__...__, - - - - - - - - - - I. -'- AN ANALWIS 05 FHE STAPES MOBILIZATEON SURGICAL PROCEDURE AS A TREA'FMENT FOR OTOSCLEROT! C DEAFNESS Thesis for “12 Degree of M. A. MiCBIGAN STATE UNIVERSITY Davici Charles Shepherd 1957 LIBRARY Michigan State University AN ANALYSIS OF THE STAPES MOBILIZATION SURGICAL PROCEDURE AS A TREATMENT FOR OTOSCLEROTIC DEAFNESS by David Charles Shepherd A THESIS Submitted to the College of Communication Arts Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF ARTS Department of Speech 1957 2 DAVID CHARLES SHEPHERD ABSTRACT The stapes mobilization surgical procedure was originally conceived in 1876,by Kessel; abandoned in the early nineteen hundreds in favor of the fenestration operation; and revived in 1952 by Rosen. Since its revival, stapes mobilization has been practiced internationally and new surgical techniques have been developed. The purpose of this study was to present a picture of the current status of the stapes mobilization surgical procedure. The methodology involved bibliographical research of the following: (a) anatomy and physiology of the human ear; (b) nature of the fenestration operation; (c) history of stapes mobilization; (d) nature of otosclerosis; (e) history of stapes mobilization; (f) nature of the fenes- tration operation; (g) preoperative audiometric testing; (h) diagnosis of, and candidate selection for, stapes mobilization; (i) objectives of stapes mobilization; (j) preoperative care; (k) anesthesia involved; (1) surgical techniques; (m) surgical audiometry; (n) operative compli- cations; (o) post-operative care; (p) evaluation criteria; (q) review of stapes mobilization results; (r) personal opinions of surgeons regarding stapes mobilization. The other research source involved the personal ob- servation by the author, of three stapes mobilization operations performed by Dr. Harold F. Schuknecht at Henry 3 DAVID CHARLES SHEPHERD ABS TRACT Ford Hospital on April 27, 1957. Dr. Schuknecht is an Associate Surgeon in the Division of Otolaryngology at Henry Ford Hospital in Detroit, Michigan. The author had the opportunity to assist Dr. Schuknecht by performing the surgical audiometrical phases of the operations. The conclusions were as follows: A. In regard to diagnosis of stapes ankylosis and the selection of prospective candidates for stapes mobili- zation: (l) A thorough otologic examination and audiometric testing battery are necessary in the diagnosis of stapes ankylosis. (2) Post-operative results cannot be predicted accurately. (3) A stapes mobilization candidate classified as "ideal" cannot be guaranteed a successful post-operative result. B. In regard to the operation: (1) The stapes mobilization surgical procedure is not a standard operation. Surgical methods that are employed depend upon the otologic surgeon performing the Operation. (2) Stapes mobilization l surgery is not‘"simple,' its administration requires a skilled otologic surgeon. (3) Surgical audiometry is essential as a guide to aid the surgeon in determining the effectiveness of his mobilization techniques. (4) Pre- operative and post-operative care are minor. C. In regard to post-operative results: (1) Stapes mobilization has restored normal hearing in some cases. u DAVID CHARLES SHEPHERD ABSTRACT (2) Operative complications can produce post-operative hearing losses more severe than preoperative hearing losses. (3) Immediate post—operative successful results have re- gressed, in some cases, to their preoperative level over a period of time following the operation. (A) The time span between the operation and post-operative audiogram is signi- ficant when evaluating post-operative results. (5) The amount of time necessary, before a post-operative gain in hearing will stabilize, is unknown at this time. (6) Stapes reankylosis can result post-operatively. However, if this occurs, another stapes mobilization operation, or a fenes— tration operation on the same ear, can be performed. (7) Recent improvements in mobilization techniques have increased the percentage of successful results. ACKNOWLEDGMENTS The author wishes to express his sincere appreciation to Dr. Max Nelson for his interest, unfailing cooperation and invaluable guidance; to Miss Lucy Moore for her con- structive criticism and counsel;and to Dr. Charles Pedry for his helpful comments initiated during the production of this thesis. The author is deeply indebted to Dr. Harold F. Schuknecht, Associate Surgeon, Division of Otolaryngology, Henry Ford Hospital, Detroit, Michigan, for the opportunity and privilege he extended in allowing the author to observe and assist in three stapes mobilization operations performed by him. Dr. Schuknecht was also instrumental in providing valuable information, through personal correspondence, which was unobtainable in the published materials reviewed by the author. Totflsswife whose encouragement and understanding provided the sufficient motivation to complete this study and whose assistance in proofreading the material was in— valuable, the author expresses his extreme gratitude. D.C.S. TABLE OF CONTENTS CHAPTER I. INTRODUCTION. The problem . Purpose of the study . Limitations imposed Value of the study. Definition of terms Otosclerosis. Otosclerotic deafness. Stapes mobilization Method of procedure Procedure. II. ANATOMY AND PHYSIOLOGY OF THE HUMAN EAR. External ear. The auricle External auditory meatus. The middle ear Tympanic membrane Tympanic cavity. Eustachian tube. . . . Ossicular chain. . . . . . The malleus . . . . The incus. PAGE \OCIDCIDNU'IUWUTJI'UOUUUUIDD.) H O 11 12 14 IA 14 15 iv CHAPTER PAGE The stapes. . . . . . . . . l6 Ligaments of the ossicular chain . l6 Muscles of the ossicular chain .. . 17 Value of the ossicular mechanism . 18 Assemblage of the middle ear components 18 The internal ear. . . . . . . . . 2O Bony labyrinth . . . . . . . . 20 The vestibule. . . . . . . . 22 Oval window . . . . . . . . 22 Semi-circular canals . . . . . 23 Bony cochlea . . . . . . . . 23 Round window . . . . . . . . 24 Membranous labyrinth . . . . . . 2A Membranous cochlea . . . . . . 25 Organ of Corti . . . . . . . 26 Process of sound transmission within the inner ear. . . . . . . . 26 Assemblage of the human ear components . 28 III. BACKGROUND. . . . . . . . . . . . 30 Nature of otosclerotic deafness. . . . 31 Histopathology of otosclerosis . . . 32 Air conduction deafness due to otosclerotic growth. . . . . . 38 Etiology of otosclerosis . . . . . AO Incidence . . . . . . . . . AA CHAPTER PAGE History of stapes mobilization. . . . . A5 Kessel. . . . . . . . . . . . A6 Miot . . . . . . . . . . . . 48 Blake . . . . . . . . . . . . 50 Jack . . . . . . . . . . . . 51 Sibenmann. . . . . . . . . . . 52 Stapes mobilization discontinued . . . 53 The advent of fenestration . . . . . 53 Holmgren . . . . . . . . . . . 5A Herberts . . . . . . . . . . . 55 Rosen . . . . . . . . . . . . 56 Fenestration operation . . . . . . . 58 Pure-tone audiometric testing . . . . 59 Pure-tone audiometer . . . . . . 60 The decibel . . . . . . . . . 60 The audiogram . . . . . . . . 61 Air conduction and bone conduction . 61 Selection of prospective candidates . . 61 Objectives of fenestration . . . . . 6A Fenestration operation procedure . . . 66 Fenestration results . . . . . . . 69 Causes of fenestration failures . . . 7O Post-operative complications . . . . 71 IV. PREOPERATIVE AUDIOMETRIC TESTING_. . . . . 73 Pure-tone audiometric testing . . . . . 75 - A??? u -_ 3..-; tall“ I CHAPTER The administration of pure- audiometric tests. Pure-tone audiometry as an diagnosis Pure-tone audiometry as an candidate selection Problem of bone-conduction Tuning fork tests. Rinne test . . . . Interpretation of Rinne Weber test Interpretation of Weber Schwabach test. tone aid in aid in testing . test results test results Interpretation of Schwabach test results. Gelle test . . . . Interpretation of Gelle Speech audiometry. Speech reception threshold test results test . . . The administration of speech recep- tion threshold tests Interpretation of speech reception results. .. . Speech discrimination test. Speech discrimination test "Score" and "loss". . . vi PAGE 76 78 81 BA 86 88 89 89 90 92 93 93 94 9A 95 97 99 99 101 CHAPTER Interpretation of speech discrim- ination results. Value of audiometric testing. V. STAPES MOBILIZATION. . . . . . Diagnosis and candidate selection Other factors to be considered in diagnosis . . . . . . . . Diagnosis of uncomplicated cases of stapes ankylosis. . Diagnosis of complicated cases of stapes ankylosis. Diagnostic summary . Selection of prospective candidates Objectives of stapes mobilization Objective in uncomplicated cases Objectives in complicated cases. . Physiological objective of stapes mobilization . . . . Stapes mobilization possibilities . Preoperative care . . . . . . . Preoperative medication . Preoperative medication prior to hospital entry . . . . . Preoperative medication employed after hospital entry . . . . vii PAGE 101 102 103 104 104 108 110 111 111 113 113 114 116 117 118 119 119 120 CHAPTER Preoperative physical preparation of the patient. . . . . . . . Anesthesia . . . . . . . . . . Solution components . . . . . Methods of injection. . . . . . Surgical techniques . . . . . . The incision . . . 9 o'clock to 3 o'clock incision . 12 o'clock to 6 o‘clock incision. No incision . . . . . . . Purpose of incision . Entrance into the tympanic cavity . The superior method . The anterior method Control of bleeding . . . . . Exposure of the middle ear structures The bony canal rim Chorda tympani nerve. . . . . Mobilization of the stapes footplate Application of pressure. Initial test of mobility . . The indirect methods of mobilization The "no incision" method of mobili- zation . . . . . . . . . . The direct methods of mobilization The determination of footplate mobilization . viii PAGE 122 124 124 126 128 131 131 132 134 134 134 135 136 139 140 140 143 145 148 149 154 165 167 171 CHAPTER Closure of the tympanic cavity. . . Tympanic membrane and skin flap replacement. . . . . . . . Packing and dressing application. Surgical audiometry Live-voice surgical audiometry. . Pure-tone surgical audiometry . Step 1. . . . . . . . . . Step 2. . . . . Step 3. . . . . . . . . . Step 4. . . . . . . . . . Schuknecht's surgical audiometric procedure. . . . . . I. . . Operations of Dr. Harold F. Schuknecht The first operation . . . . . Preoperative audiogram . . . Narrative of the surgical procedure Post-operative audiometric results The second operation . . . . . . Preoperative audiogram . . . . Narrative of the surgical procedure Post-operative audiometric results The third operation . . . . Preoperative audiogram . . . . Narrative of the surgical procedure Post—operative audiometric results ix PAGE 174 174 175 177 178 179 182 182 183 184 184 185 186 186 188 191 192 192 192 195 196 196 197 199 CHAPTER VI. Operative complications; Crural fractures . . . . . . Luxation of the inducostapedial joint Perforations of the tympanic membrane Facial nerve injury . . . . . . Inner ear complications. Other complicating factors. Incidence of permanent complications Post-operative care . . Ambulation . Alleviation of pain . Antibiotic administration . Alleviation of vertigo and nystagmus Hospital dismissal Dressing and packing removal Healing of the surgical field. Post-operative audiometric testing . EVALUATION OF STAPES MOBILIZATION Evaluation criteria . Success criteria . . . . . . Achievement of the 30 db level Eradication of the air-bone gap Partial gain criterion . Failure criteria . Over-all evaluation criteria . PAGE 200 200 201 203 204 205 206 207 208 208 209 209 210 211 212 213 214 215 215 216 217 218 219 219 220 xi CHAPTER PAGE Review of stapes mobilization results. . 221 Results obtained by Goodhill. . . . 221 Results of Goodhill's first one- hundred cases . . . . . . . 222 Results of Goodhill‘s second, or most recent group of eighty-nine cases . . . . . . . . . . 222 Goodhill‘s over-all results . . . 223 Results obtained by Derlacki, Shambaugh and Harrison . . . . . . . . 223 Results of technique #1 . . . . 224 Results of technique #2 . . . . 225 Results of technique #3 . . . . 225 Results of technique #4 . . . . 226 Over-all results of Derlacki, Sham- baugh and Harrison. . . . . . 226 Results obtained by Scheer . . . . 227 Results obtained by Rosen. . . . . 229 Results obtained by Meurman and Meurman 230 Results obtained by Myers and Ronis . 231 Results obtained by House. . . . . 232 Review of significant result trends . 233 Personal opinions of surgeons regarding stapes mobilization. . . . . . . 234 General opinions. . . . . . . . 234 xii CHAPTER PAGE Current status of stapes mobilization 234 Success determinants. . . 236 Causes of failures . . . . . . 237 Comparison of the value of stapes mobilization and fenestration. . . 238 The future prospects of stapes mobilization . . . . . 24O VII. CONCLUSIONS. . . . . . . . . . . . 242 Diagnosis and candidate selection . . . 242 The operation . . . . . . 242 Post-operative results . . . . . . . 243 BIBLIOGRAPHY . . . . 245 LIST OF FIGURES* Figure Page 1. The Auricle. . . . . . . . . . . . 8 2. The External Auditory Meatus . . . . . . 9 3. The Tympanic Membrane . . . . . . . . 11 4. The Malleus. . . . . . . . . . . . 15 5. The Incus . . . . . . . . . . . . 15 6. The Stapes . . . . . . . . . . . . l6 7. Assemblage of the Middle Ear Components .. . l9 8. The Bony Labyrinth -. . . . . . . . . 21 9. The Membranous Labyrinth . . . . . . . 25 10. The Placement of the Membranous Labyrinth within the Bony Labyrinth . . . . . . 27 11. The Assemblage of the Human Ear . . . . . 29 12. The Right Ear Canal after Incision, the Dis- section of the Skin Flap and Tympanic Membrane, and Folding According to the Superior Method. . . . . . . . . . 135 13. The Right Ear Canal After Incision, the Dis- section of the Skin Flap and Tympanic Membrane, and Folding Accoring to the Anterior Method. . . . . . . . . . 136 14. Indirect Method of Mobilization, with Pressure Applied to the Stapes Neck . . . . . . 156 Figure 15. Indirect Method of Mobilization with Pressure Applied to the Incudostapedial Joint. Myerson Technique. 16. Indirect Method of Mobilization with Pressure Applied to the Incus and Directed through the Incudostapedial Joint 17. Indirect Method of Mobilization, with Pressure Applied to the Head of the Stapes l8. Indirect Method of Mobilization, with Pressure Applied to the Short Process of the Malleus, According to the Myerson Technique 19. Direct Method of Mobilization, Used Anteriorly and Inferiorly 20. Direct Method of Mobilization, Applied Directly to the Footplate with Explorer with Pressure xiv Page 158 160 161 166 168 169 *The Figures included within this study were designed and painted in water colors by the author. were reproduced by the Michigan State University Photography Laboratory using the "Negative-Positive Eastman Color Process. The final copies are termed, "C— —type prints The original copies Ideas for picture composition were gather from those pic- tures appearing in the various publications reviewed by the author. 11 Audiogram 1. LIST OF AUDIOGRAMS Page Stapes ankylosis in the right ear. The Carhart notch is indicated in the bone conduction curve. . . . . . . . . 80 Degree of bone conduction loss allowed in order that the patient may receive favorable results from fenestration . . 82 Degree of bone conduction loss allowed in order that the patient may receive favorable results from stapes mobilization 83 Preoperative audiometric results of the first patient. . . . . . . . . . 187 Preoperative audiometric results of the second patient . . . . . . . . . 192 Preoperative audiometric results of the third patient. . . . . . . . . . 197 CHAPTER I INTRODUCTION Stapes mobilization is a recently revived surgical procedure administered as a treatment for otosclerotic deafness. Deafness of this type is the result of the form- ation of spongy bone substance within the bone of the inner ear capsule that impairs the stapes and inhibits its mobility. The mobility of the stapes is a necessary function for the proper transmission of sound waves from the ear drum, through the middle ear, into the inner ear. 'The idea of stapes mobilization was originally con- ceived in 1876, by Kessel.l Since the early nineteen hundreds it had been disregarded by most members of the medical pro- fession because of various unsuccessful attempts to prove its value. In 1916, Holmgren2 introduced a surgical method of opening the horizontal semi-circular canal to create an acoustic route, in order that sound waves could by-pass the 1Victor Goodhill, "Present Status of Stapedolysis," The Laryngoscope, 66:333,April, 1956. 2Meyer Wiener and others (eds.), Progress in Optholom- molo y and Otolaryngology (New York: Grune and Stratton, 1952;, p. 408} fixed stapes. This idea was later developed by Sourdille3 4 developed the technique further in 1926 and in 1938 Lempert and termed it the fenestration operation. This operation was then adopted universally as a surgical treatment for otosclerotic deafness. In 1952, Rosen5 revived the method of stapes mobili- zation and with it the interest of many of those persons engaged in the field of Otology. Since its revival there has been much skepticism on the part of otologic surgeons regarding the value of stapes moblization. Goodhill reasons, "the earlier failures in the stapes approach, and recent refinements and successes in fenestration surgery, obviously created a skeptical attitude toward its revival."6 I. THE PROBLEM Purpose of the Study The purpose of this study is to present a picture of the current status of the stapes surgical procedure. Limitations Imposed Research is limited to bibliographical sources and personal observations by the author of three stapes mobili- zation operations. 31bid. “Ibid. 5Goodhill, op; cit., p. 333. 6Ibid. w — Value of the Study A study of the nature of stapes mobilization would be of considerable value to persons directly affected by otosclerotic deafness as an aid toward their understanding of its history, preoperative care, method, postoperative care, complications, successes, failures and value as a surgical treatment for otosclerotic deafness. This study would be of primary value to the author and other students in the field of Audiology as a direct insight into one of the functions of the audiologist. A major role in the stapes mobilization surgical procedure is played by the audiologist. II. DEFINITION OF TERMS Otosclerosis Black's Medical Dictionary defines otosclerosis as being, . . . the condition in which spongy bone forms in the capsule of the labyrinth of the ear. ."7 The word "otosclerosis" is a combination of the two .1! ll terms, oto and "sclerosis." The definitions of these two terms are: "8 oto-, a word meaning "ear. 7John D. Comrie and William Thomson, Black's Medical Dictionary (London: Adam and Charles Black, 1952), p. 658. 8Clarence L. Barnhart (ed.), The American College Dictionary (New York: Harper and Brothers, 1953), p. 858. sclerosis,.a hardening or induration of a tissue or part; increase of connective tissue or the like at the expense of more active tissue.9 A definition of otosclerosis derived from the com- bination of the meanings of "oto" and "sclerosis" might be, a hardening of a tissue that increases at the expense of more active tissue in the labyrinth of the inner ear. Otosclerotic Deafness Otosclerotic deafness occurs when the otosclerotic bone growth forms in the region of the oval window of the labyrinth (bony casing of the inner ear), grows to its margin and from here through the annular ligament of the stapes footplate.lO At this point, the otosclerotic bone causes the stapes to become immobile and therefore produces a conductive block in the middle ear prohibiting sounds waves from entering the inner ear. Otosclerotic deafness is primarily of an air con- ductive nature. Air conduction can be defined as the transmission of sound waves through the external ear canal and middle ear to the inner ear. However, it can also be of a nerve type if the otosclerotic condition impairs the auditory nerve. 91bid., p. 1087. 10L. Meurman and O. Meurman, "Stapes Mobilization in Otosclerosis; Primary Results of a Review of 63 Cases," A.M.A. Archives of Otolaryngology, 62:166. August, 1955. This study will be concerned mainly with the air conductive type, as stapes mobilization is of little value to sufferers of nerve deafness caused by otosclerosis. Stapes Mobilization Stapes mobilization is a surgical procedure employed for the reopening of a closed acoustic pathway in the middle eearn It is a method practiced by an otologic surgeon to 211.1eviate the condition of otosclerotic deafness. The procedure involves the artificial mobilization <3;f‘ the fixed stapes by a surgeon in an effort to break it :ffizree from an otosclerotic condition. The stapes is the fithLnermost of three small bones in the middle ear of man. III. METHOD OF PROCEDURE I?1?ocedure The method of procedure for the development of this Eftudy'involved bibliographical research of the following: (a) Anatomy and physiology of the human ear; (b) nature of f the ear-wax and hairs. Polyak says: The function of this earwax and the hairs is to protect the skin of the meatus from desiccation (to dry up) and to prevené intrusion of insects and other foreign bodies. The purpose of the external auditory meatus is to Clirect the sound vibrations to the tympanic membrane. II. THE MIDDLE EAR The component parts of the middle ear that will be <1iscussed in this section are the tympanic membrane, the tympanic cavity, the eustachian tube, the auditory ossicles and.their ligaments, and the muscles of the ossicular chain. All of the above mentioned components play important Ixales in the basic function of the middle ear in the hearing Errocess. In regard to the function of the middle ear, Browd 6Bast and Anson, op. cit., p. 13. 7Poiyak, loc.cit. 81bid. 11 explains, "It is nothing more than an amplifier. It picks up sound waves, increases their intensity and delivers them to the oval window (the oval window is discussed in Section 111)."9 Browd further states: The middle ear operates on the principle that sound waves lose intensity when they pass from rare medium (air) to a denser medium (fluid), but that this loss can be overcome if they are first made to strike a larger vibrating surface than that which separates the two media. This surface is the ear- drum, or tympanic membrane,10 UDympanic Membrane The tympanic membrane, Figure 3, better known as the eardrum, separates the external auditory canal from middle ear. Polyak describes the tympanic membrane n as a, . . . glistening, greyish-pink curtain, placed at a slant at the 11 deepest point of the meatus;" Figure 3. The tympanic membrane According to East and Anson the tympanic membrane is <3omposed of three layers. The layer facing the external Eruditory meatus is skin. The medial layer consists of 9Victor L. Browd, The New Way to Better Hearing (New ift>rkz Crown Publishers Inc., 1951), p. 29} lOIbid. llPolyak, op. cit., p. 67. 12 fibrous lamina (narrow thin plates of sensitive tissue). The layer facing the tympanic cavity consists of a mucous membrane.12 The tympanic membrane seals the external auditory canal completely. Polyak describes the placement of the eardrum in the following manner: The tympanic membrane is held in place by a thickened fibrous annulus, or ring, fitted into a circular grove. at the inner end of the bony meatus. In this way the tension of the tympanic membrane is maintained at a constant level. Browd describes the size of the eardrum in relation to the eize of the membrane covering the oval window. He also explains its value. Browd states: Its area is about thirty times that of the skin covering the oval window and it increases a pfirson's hearing acuity by approximately 30 per cent. When viewing this membrane there may be seen running from above and extending to approximately the center, an opaque whitish streak. This streak indicates the handle of the malleus, which is one of the bones of the ossicular chain. Tympanic Cavity The tympanic cavity is principally a chamber sheltering the bones, ligaments, and muscles of the ossicular l2Bast and Anson, op. cit., p. 15. 13Polyak, op. cit., p. 69. luBrowd, loc. cit. l3 mechanism. A necessary function of this cavity is that of neutralizing sound waves. Polyak explains: Of no less significance is its role as a barrier . . . an acoustically dead space. . . against whose irregular walls thg sound waves break up and are thus neutralized. This author also explains that it serves to: . . . maintain the atmospheric pressure on the inner, acoustically blind side of the tympanic membrane equal to the pressure on its outer, acoustically active side.1 The tympanic cavity separates the external auditory meatus from the bony labyrinth of the inner ear (the bony labyrinth is discussed in Section III). East and Anson describe: The tympanic cavity consists of an upper part, the epitympanic recess, which extends upwards beyond the level of the tympanic membrane; and the tympanum proper which is situated medial to the membrane. Within the wall separating the tympanic cavity from the bony labyrinth are two covered holes, one above the other. The upper hole is oval shaped and the lower hole is round. These two apertures allow for the passage of sound waves from the tympanic cavity to the bony labyrinth. They communicate directly with the oval and round windows of the bony labyrinth. East and Anson observe that the walls of the tympanic cavity are lined with a thin mucous membrane. This membrane l5Po1yak, op. cit., p. 115. 15110161. l7Bast and Anson, op. cit., p. 16. 14 also covers the bones of the ossicular chain and the tendons of the stapedius and tensor tympanic muscles, all of which are located within the tympanic cavity.18 Eustachian Tube The eustachian tube extends from the back of the nose and throat to the tympanic cavity. Stevens explains its function in the hearing process: Ordinarily the eustachian tube is closed at its lower end, but it regularly opens during the act of swallowing and thereby allows equalization of any difference in pressure on the two sides of the tympanic membrane.1 Ossicular Chain The principal parts of the ossicular chain are three small bones. The first bone is connected to the tympanic membrane. This bone is called the malleus or hammer. Con- nected to the malleus is the incus or anvil. The third bone in the chain is named the stapes or stirrup, and it joins the entire ossicular chain to the oval window of the bony inner ear labyrinth. The malleus. Bast and Anson describe the malleus, Figure 4, as consisting of a head, neck, a manubrium (resembling a handle) and two processes (bony outgrowths). The manubrium is attached to the tympanic membrane. The 181b1d. 19Stanley Smith Stevens and Hallowell Davis, Hearing (New YOrk: John Wiley and Sons, Inc., 1938), p. 249. 15 lateral process of the malleus rests against the eardrum, and its anterior process serves as a point of attach- ment for its anterior ligament. A ligament is also attached to the head of the malleus. Bast and Anson Figure 4. The malleus state, "On the posterior (rear) aspect there is a notch-like articular surface, for articu- lation with the body of the incus;"20 The incus. Connected to the articular surface of the malleus is the incus, Figure 5. According to Bast and Anson, the incus is shaped like a premolar tooth. They state, "It is divisible into a body and two crura (limbs) of unequal Figure 5. length."21 The short crus is a point The incus of attachment for a ligament. The longer crus extends downward. On the bottom end of the long crus there is a small knob of bone. It is called the '"lenticular process" and serves as an articulation surface for the head of the stapes.22 2OBast and Anson, op. cit., pp. 19-20. 2lipid. 22 Ibid. 16 The stapes. The stapes, Figure 6, is attached to the incus and is the last link in the ossicular chain. According to Bast and Anson, the principle parts of the stapes are the head, neck, two crura and the staples footplate. The foot- plate fits into the oval window of Figure 6. The stapes the inner ear labyrinth and completes the sound transmission chain from the tympanic membrane across the tympanic cavity to the inner ear.23 Ligaments of the ossicular chain. There are five ligaments that are attached to the bones of the ossicular chain. East and Anson explain that the ligaments are, " certain bands which connect the bones to the walls of the tympanic cavity and serve to restrain their movements."2u Three ligaments connect the malleus to the tympanic cavity. One is attached to the head of the malleus, one extends from the neck, and one extends from its anterior process. The short crus of the incus is a connecting point for the ligament attaching it to the tympanium wall. The ligament that is of primary concern in otosclero- tic deafness is the annular ligament. This is the ligament 2 3Ibid. 24East and Anson, op. cit., p. 21. 17 of the stapes that connects the margin of the stapes foot- plate to the oval window of the bony labyrinth. Otosclerotic bone grows through the annular ligament and fuses the foot- plate to the margin of the oval window. Muscles of the ossicular chain. There are two muscles attached to the bones of the ossicular chain. These are the tensor tympani muscle and the stapedial muscle. Stevens and Davis describe the placement of the tensor tympani and its effect upon the ossicular chain: The tensor tympani attaches to the handle of the malleus and draws it inward, thereby placing the tympanic membrane under tension. The effect of its action on the stapes is to force the footplace up- ward and inward into the oval window and its action is thus antagonistic to the action of the stapedius.25 These authors state that the stapedius muscle: . is attached to the head of the stapes close to its articulation with the incus. Its contraction draws the head of the stapes outward and downward in the direction opposite to the inward and upward move- ment of the long process of the incus caused by in- crease of pressure on the outside of the tympanic membrane.2 Browd explains his opinion of the function of these two muscles: By contracting automatically when sound waves of great force strike the ear, they reduce the movements of the middle ear parts by as much as 4Q%. This function enables us to understand conversation and 2 5Stevens and Davis, op. cit., pp. 250-251. 26Ibid. 18 hear in comfort in noisy surroundings, and makes the middle ear the pnly amplifier which boasts an auto- matic control.2 These muscles cannot be seen in the tympanic cavity, only their tendons project into this area. The muscles lie within bony canals in the cavity walls. Value of the ossicular mechanism. Stevens and Davis list the following four primary values of these structures. They state: 1. They provide for preferential delivery of sound-energy to the oval window as opposed to the round window. 2. They serve to collect energy from a relatively large cross-section of air and deliver it to the much smaller area of the footplate of the stapes. 3. Theyprovide a slight mechanical reduction in amplitude of motion between the tympanic membrane and the part of the stapes which is directly in contact with the fluid of the cochlea. (This fluid is dis- cussed in Section III.) 4. In conjunction with the intra-aural muscles, they provide a protective mechanism for the inner ear against loud low tones without undue impaégment of hearing for faint tones of high frequency. Assemblage of the Middle Ear Components Figure 7, illustrates the assemblage of the eardrum, the assemblage of the eardrum, malleus, incus, stapes, and ligaments and muscles of the ossicular chain within the tympanic cavity. 27Browd, op. cit., p. 31. 28Stevens and Davis, op. cit., p. 259. l9 Figure 7. Assemblage of the middle ear 0 components The tube running down toward the right-hand corner of the illustration indicates the eustachian tube. The blue area seen on the right-hand side of the eustachian tube represents a section of cartilage that supports the tube. The red muscle extending toward the tympanic cavity is the tensor tympani muscle. Its tendon can be seen as a thin white line running toward the handle of the malleus. As was previously stated, this tendon attaches to the handle. The stapedius muscle and its tendon cannot be seen in the illustration. However, the tendon extends from the rear wall of the tympanic cavity and attaches itself to.the head of the stapes. Only three ligaments can be seen. Two extend from the malleus, one is attached to the neck and one is attached to the head. The other ligament pictured is attached to the head of the incus. 20 III. THE INTERNAL EAR The internal ear is a very intricate and complicated mechanism. A detailed discussion of its complete make-up is not necessary to this study. However, an understanding of its basic components and their functions is of importance in comprehending the hearing process and the effects of oto- sclerotic growth on the hearing mechanism. This section will be concerned with the bony labyrinth and its divisions, which are the vestibule, the semi-circular canals and the cochlea. Other elements that will be con— sidered are the oval window, the round window, the membranous labyrinth, the membranous cochlea, and the organ of Corti. The fluids of the inner ear and the auditory nerve will be included within the discussions of the specific inner ear components to which they are related. All of these elements are important for the proper transference of sound waves from the stapes of the ossicular chain to the brain. Bony Labyrinth This portion of the inner ear is a bony capsule that encases all of the inner ear mechanism. According to Wolfson and Fischer the bony labyrinth consists of three bone layers. The external layer (periostal capsule) is made up of compact bone tissue. The medial (en- chondral capsule) consists of a very thick compact layer of bone enclosing interglobular bodies (a spherical mass). 21 The innermost layer (endostal capsule) is made up of a layer of membranous bone. It is within the bony layers of the labyrinth that otosclerotic growth takes place.29 The bony labyrinth, Figure 8, is divided into three parts; the vestibule, the semi-circular canals, and the cochlea. All of these divisions of the labyrinth contain perilymph. Stevens and Davis explain, "They contain a clear fluid, the perilymph, in which the membranous labyrinth is situated."30 These three divisions are in direct communi— cation with each other. Figure 8. The bony labyrinth 29Louis E. Wolfson and Jose n Fischer The Inner Ear (New YOrk: Grune and Stratton, l9 3), p. 178. 30 Stevens and Davis, op. cit., p. 268. I rim"? I'Q - r‘ The vestibule. In Figure 8, the vestibule can be seen as the central portion of the labyrinth. Stevens and Davis observe: The vestibule is the central part of the osseous (bony) labyrinth, and is situated just medial (toward the medium plane which divides the body gpto right and left halves) to the tympanic cavity. Within the wall of the vestibule directly facing the tympanic cavity is the oval window into which the footplate of the stapes is attached. Oval window. In Figure 8, the oval window is located in the upper surface of the vestibule. Marshalland Lazier explain that the stapes footplate: . . . lies in a small oval aperture, the fenestral vestibule, in the bony median wall of the tympanig cavity leading to the vestibule of the inner ear. 2 According to Browd, the oval window, ". . . is sealed with a delicate membrane so that no fluid can escape."33 He further states, in reference to the placement of the stapes, the stirrup, rests with its footplate firmly secured against the delicate skin covering of the oval window."34 31Ibid. 32Clyde Marshall and Edgar L. Lazier, Human Anatomy (Philadelphia: W. B. Saunders Company, 1955), p. 351. 33Browd, loc. cit. 34 Ibid. 23 The area of the oval window is of principle concern in the stapes mobilization surgical procedure. It is in this region that the stapes becomes fused and thus leaves the ossicular chain immobile. Semi-circular canals. Extending posteriorly (to the rear) from the vestibule are the semi-circular canals.. They can be seen in the left-hand portion of Figure 8. Marshall and Lazier state, "These canals are at right angles from one another."35 There are three canals. Their primary function involves the sheltering of the orgal of balance. Stevens and Davis state: They are not concerned with the function of hearing. They do, nevertheless, form part of the total chamber to which changes of pressure, generated by movement of the footplate of the stapes, are delivered.3 In Chapter III, Section III, the semi-circular canals will be of some concern. That portion of this study will concern the fenestration operation. The area of the semi- circular canals is of utmost importance in the fenestration operation. Bopy cochlea. Opening anteriorly (to the front) of the vestibule is the bony cochlea. It can be seen in the right-hand portion of Figure 8. Stevens and Davis describe its appearance: 35Marshall and Lazier, op. cit., p. 352. 36Stevens and Davis, op. cit., p. 269. 24 In shape it resembles a snail-shell. It measures some 5 mm. from base to apex, and its breadth across the base is about 9 mm.3 The bony cochlea protects the most important organ of heaxfiixng, the organ of Corti. The organ of Corti is encased withjxrl the bony cochlea. Round window. When the bony labyrinth in Figure 8, the rw:n4nd window can be seen below the oval window. Marshall and Lazier explain: Below the fenestra vestibulae (oval window) is a snTLaller-hole, the fenestra cochlea (round window), MHfLiCh.iS closed by the secondary tympanic membrane.38 The function of the round window and its membrane in thelneezaring process is to yield to the inner ear fluid waves activeagted by the action of the stapes footplate against the membrane of the oval window. MembrfiaJnous Labyrinth It was earlier stated that all three divisions of the bCDIly labyrinth contain a fluid called perilymph. Within this IDeerilymph the membranous labyrinth, Figure 9, is some- what ESIlspended. IMarshalland Lazier explain: 'Within the bony labyrinth lies a system of iI‘L'tferconnected, delicate, membranous sacs and tubes, tklea nmmfluenous labyrinth, lined with epithelium N 37Ibid . :38Marshall and Lazier, op. cit., p. 351. 25 (tissue, one cell layer thick). . . . The membranous labyrinth is filled with a clear fluid, the endolymph. 39 Figure 9. The membranous labyrinth The membranous labyrinth extends throughout the vestibule, semi-circular canals and the cochlea. Membranous cochlea. This is the portion of the mem- branous labyrinth extending into the bony cochlea. It can be seen in the right-hand side of Figure 9. Polyak states: Like the rest of the membranous labyrinth, the membranous cochlea is filled with fluid, the endolymph, and like it, is surrounded by the. . . ossious cpghlea of the bony labyrinth, which contains perilymph. Polyak describes the membranous cochlea in the following manner: . . a long and narrow membranous duct (tube) wound spirally around its axis, clockwise in the 4 left ear and counterclockwise in the right ear. 1 39Ibid. 40Polyak, op. cit., p. 7. 41Ibid. 26 The principal organ of hearing, the organ of Corti, is enclosed within the membranous cochlea. Organ of Corti. According to Polyak the organ of Corti extends throughout the entire length of the membranous cochlea. This author explains that in structure it is a stripe of especially modified sensory epithelium. He states that it also: . .consists of specific sensory hair cells, lodged in the supporting framework. There are, besides, in contact with the hair cells, nerve fibersuglong which impulses are transmitted to the brain. Browd explains the cmgan of Corti by compairing its hair cells and nerve fibers to the keys of a piano keyboard. He explains: . . . it has an entire keyboard of fifteen hundred keys. Each key responds to the pressure of pure tones of a particular frequency (number of vibrations per second) and to no others; each produces a sound whose pitch differs from that of any other key on the board . . . actual size of our keyboard is one and one- quarter iflghes in length and one-hundredth of an inch in width. The above mentioned nerve fibers are part of the auditory nerve that carries the nerve impulses, that are transformed from the initial sound waves, to the brain. Process of Sound Transmission Within the Inner Ear A complete description of the workings of the inner ear mechanism is beyond the scope of this study. However, 4 4 ' 2Ibid. 3Browd, op. cit., p. 18. 27 its essential function within the hearing process will be discussed briefly. Figure 10._ The placement of the membranous labyrinth within the bony labyrinth. Figure 10 illustrates the placement of the membranous labyrinth within the bony labyrinth. In summary, the mem- branous labyrinth is surrounded with perilymph and contains another fluid called endolymph. Within the cochlear portion of the membranous labyrinth is the receptor organ of hearing, the organ of Corti. Stevens and Davis explain the structure of the bony labyrinth which makes the inner ear accessible for the transmission of sound vibrations by its fluid medium. They state: The bony labyrinth is a practically closed chamber with rigid walls, except for the oval and round windows. The fluid within it is incompressible, and therefore, when the footplate of the stapes vibrates, significant mass movements of the fluid within the labyrinth can occur only by virtue of the yielding of the round window membrane. 4 M‘Stevens and Davis, op. cit., p. 276. 28 Therefore, the sound vibrations carried to the oval window membrane by the bones of the ossicular chain are, in this area, transferred into the fluids of the inner ear. Browd explains: Air waves strike against the oval window and con- tinue on as fluid waves. These fluid waves are STrPASIE Sibigiigigbfigrd according to the frequency Each hair cell of the keyboard, or organ of Corti is activated by the fluid waves possessing the specific fre- quency the cell is designated to receive. The nerve fibers are then activated by each fiber's corresponding hair cell. At this point, the frequencies carried by the fluid waves are transformed into nerve impulses. These nerve impulses are conveyed along the auditory nerve to a specific area of the brain. Within this brain area the nerve impulses are interpreted into understandable messages. It should be mentioned that the above explanation of the inner ear function is very simply stated. By no means does it include the many specialized membranes and other intricate mechanisms that are involved in the hearing process. The author feels that a discussion involving these elements would not be pertinent to this study. IV} ASSEMBLAGE OF THE HUMAN EAR.COMPONENTS In order that the reader may not be misled by the sizes of the foregoing illustrations of the human ear uBBrowd, op. cit., p. 20. 29 components, a total assemblage of these components in approx- imate actual size is represented in Figure 11. Figure 11. The assemblage of the human ear. Figure 11 illustrates the assemblage of the auricle, external auditory meatus, tympanic membrane the ossicular mechanism within the tympanic cavity, and the approximate placement of the bony labyrinth of the inner ear. Actually the bony labyrinth would not be seen, for it is encased within the petrous bone. However, in order that the reader can visualize its relationship with the other components, it is represented as a darkened area to the right of the tympanic cavity. CHAPTER III BACKGROUND. This chapter of the study will concern a discussion of the background information directly or indirectly related to the stapes mobilization surgical procedure. The information directly related to stapes mobili- zation that will be considered involves the nature of oto- sclerosis and the history of the stapes mobilization operation. The author feels that a discussion concerning these two elements is necessary in order that the reader may obtain an understanding of the cause of otosclerotic deafness and the development of one surgical procedure (stapes mobilization) employed to alleviate this condition. The fenestration operation is indirectly related to stapes mobilization in regard to the selection of prospective candidates and final operational goals. A patient who is suitable for the fenestration operation is also suitable for stapes mobilization. Both operations are administered in an effort to alleviate the condition of otosclerotic deafness, although their methods of approach differ. This chapter of the study will be divided into the following three sections: nature of otosclerosis, history of stapes mobilization, and the fenestration operation. 31 I. NATURE OF OTOSCLEROTIC DEAFNESS In 1897, Politzer gave a clinical picture of oto- 1 According sclerosis which is unchanged since that time. to Wolfson and Fischer, Politzer was the first to recognize otosclerosis as a primary disease of the labyrinthine capsule. He described the otosclerotic foci (points from which the disease develops) as proliferating (budding) bone growths occurring in certain areas of the capsule. There is a general feeling among most authors that this term is inaccurate in classifying the disease. Eggston and Wolff explain that "otosclerosis" is a misnomer because sclerosis does not begin until late in the development of the disease.3 Wolfson and Fischer reason, "Even though we know the term is wrong. . . we use the old name applied by Politzer."u 'This section of the chapter will be divided into the following four parts: histopathology of otosclerosis, air conductive deafness due to otosclerotic growth, etiology of otosclerosis, and incidence of otosclerosis. 1Scott R. Stevenson, Recent Advances in Otolaryngology (Philadelphia: The Blakiston Company, 1949)‘,"p. 271. 2Wolfson and Fischer, op. cit., p. 176. 3Andrew Eggston and Dorothy Wolff, Histopathology pf tine Ear, Nose and Throat (Baltimore: Williams and Wilkens Company. 19117). p. 453. “Wolfson and Fischer, loc. cit. 32 Histopathology of Otosclerosis Brunner describes otosclerosis as being a primary disease of the bony capsule of the labyrinth originating within the bone of the labyrinth.5 Wolfson and Fischer explain that otosclerosis is a disease of the labyrinthine capsule and occurs in this bone of the ear organ. They mention that it has never been observed in other bones of the skeleton.6 Brunner is of the opinion that otosclerosis can be classified as a tumorous disease. He calls these tumors "otosclerotic tumors."7 Brunner states: The otosclerotic tumors are primary tumors of the bony capsule of labyrinth and probably originate in the area of the b rderline of the enchondral and periostal layers. Eggston and Wolff believe that otosclerosis is a lesion (localized structural change) of unknown etiology (cause) resumbling a tumor. Although it resembles a tumor they do not feel that it can be classified as a tumor.9 The author found that the term "tumor" is not applied to this bone disease by most authors. It is referred to as being a "lesion." 5Hans Brunner, "Pathology of Otosclerosis," A.M.A. Archives pf Otolaryngology, 55:372, March, 1952. 6Wolfson and Fischer, op. cit., p. 178. 7Brunner, op. cit., p. 376. 8Ibid. 9Eggston and Wolff, loc. cit. 33 Wolff describes an otosclerotic lesion as being, "A circumscribed (limited) area of spongy pathologic bone clearly demarcated (separated) from normal bone."lo Jackson and Coates explain the pathology of otosclero- sis in the following manner: The essential pathology of otosclerosis is absorp- tion of normal bone of the labyrinth capsuleland its replacement by a new type of bone formation. Fowler observed that otosclerosis starts as one or more foci in the otic capsule (labyrinth). From these small inactive areas of compact bone it can spread throughout the whole capsule sometimes involving the semi-circular canals. He also found cases in which these foci caused the closure of both the round and oval windows.12 Jackson and Coates state in regard to the nature of the otosclerotic foci, "The bony changes may affect the capsule in one or more foci or diffusely, and are usually symmetrical in both labyrinths."l3 Such is the nature of these foci when they are near the anterior margin of the oval window; when they are in the walls of the internal lODorothy Wolff, "Otosclerosis: Hypothesis of its Orgin and Process," A.M.A. Archives pf Otolarygology, 52:853, December, 1950. llChevalier Jackson and George Morrison Coates, The Nose, Throat and Ear and Their Diseases (Philadelphia: W. B. Saufiders Company, 19307: p. 505. 12Edmund Prince Fowler, Medicine 93 the Ear (New York: Nelson and Sons, 1947), p. 251. 13Jackson and Coates, loc. cit. 34 auditory meatus; when they appear in the apex of the cochlea; and when they appear in the areas of the semi-circular canals.lu According to Eggston and Wolff the initial phase of otosclerotic growth is characterized as being a spongifi- cation of the bone. They explain, "The disease areas are no longer solid ossified (hardened bone) structures and contain an excessive number of marrow spaces and blood vessels."15 Meurman and Meurman state that the initial phase of otosclerosis begins with the development of periosteal bone within the enchondral layer of the bony wall of the inner ear. They state, "The most usual site is right in front of the oval window."l6 Jackson and Coates describe this new bone in the following manner: Microscopically, the new bone manifests two distinct types of osseous growth: (1) A pink, rose-colored bone, due to an affinity for eosin, with thick osteoid beams and small marrow spaces; (2) a deep blue hematoxy- éinstaining spongiod bone consistinglpf a network of ony beams with large marrow spaces. Fowler explains that when the otosclerotic foci became active, there is a distinct tendency of progression. 141222. 15Eggston and Wolff, loc. cit. 16Meurman and Meurman, op. cit., p. 166. 17Jackson and Coates, op. cit., p. 508. 35 There is a localized resorption of the old bone caused by the slow destruction of the minute cavities within the bone. Within the diseased areas there is a replacement of old bone tissue by weblike bone. This process continues with more resorption of bone and its replacement by more mature web— like bone tissue with fibers, into which, later on lamellar bone is disposited.18 Brunner states: At the onset of actual otosclerosis the original bone of the labyrinth capsule is resorbed by osteoclasts and the defects are filled with newly formed bone which differs in structure from the original bone.l According to Jackson and Coates the bone changes can be grouped into four phases: 1. A primary new-bone formation. It consists of a network of blue-staining osteoid beams with small triangular or irregular-shaped bone corpuscles. Nucleated red cells, myelocytes, and fat cells, so characteristic of the red bone marrow, are not found in these spaces. This type is found in the very young or in the very rapidly progressing forms of the disease. 2. A secondary absorption of the normal capsular bone of the labyrinth. The advancing new bone by its pressure on the normal capsular bone and its blood- vessels produces a simple atrophy of the old bone with- out signs of cell activity. 3. A resorption of the new blue-staining bone. This resorption takes place through the joint action of a canaliculization process in which the bone cell cavities distend, communicate, and form canals in the bone. Giant-cell osteoclasts aid in the resorption. 18Fowler, op. cit., p. 263. 19Brunner, op. cit., p. 372. 36 4. A replacement of the new blue-staining bone by a new pink-colored bone. This pink, eosin-staining bone is laid down by osteoblasticartivity. It consists of a network of thick bony beams with nearly normal bone corpuscles. The marrow spaces contain connective tissue with lymphocytes, spindle-cells, and small blood-vessels. In the older areas of pink-colored bone, the bony beams become thicker and more compact, with lamellar systems developing around blood-vessels. 20 These authors add, "These different types of new bone may represent different intensities, or rates of growth in the new forming bone, rather than cycles in its development."21 In describing the method of otosclerotic progression Fowler says: This takes place by continuous lacunar, (grooves in developing bone which is undergoing resorption), resorption of the immediate surrounding bone along a wide front or by the diffuse occurrence of finger- like processes of a peculiar bluish bone tissue in the center of which a small blood vessel is located.22 These fingerlike processes of bluish bone tissue are called "blue mantles." Fowler reasons that perhaps these blue mantles represent the beginning of otoslerosis and are distributed by the blood stream into the labyrinth.23 According to Wolff, "blue mantles" may be considered as chemical indicators of the type of calcium being deposited. She states that these "blue mantles" occur in temporal bones and are a prominent feature of otosclerosis. Wolff believes that otosclerosis advances along blood channels and congestion 20Jackson and Coates, loc. cit. 21Ibid. 22Fowler,op. cit., p. 263. 23Ibid. 37 and hemostosis (blood formation) are frequent. The blood vessels exhibit "blue mantles."24 In summary, Brunner discusses the following character- istics of the otosclerotic lesion, or as he terms it, the "otosclerotic tumor." It is discovered only in the human labyrinth of the ear. It develops without any apparent cause. At any time it may become active or regain activity. The resorption process may result in a moderate reconstruction of the rest of the labyrinth. Thickening of the bone is often a result of otosclerosis. There is no pain connected with otosclerosis. Otosclerotic bone grows within bone.25 Wolfson and Fischer state, "There is usually a sharp line of demarcation between the normal and diseased bone."26 These authors observed that interglobular bodies are absent in the diseased area, and very large spaces of bone marrow I are seen in the otosclerotic focus. They state, "There are no changes of the bone surrounding the otosclerotic focus."27 Brunner supports this preceding statement of Wolfson and Fischer. He observed that, "There is no degeneration of the bone surrounding a growing otosclerotic foci."28 However, he also adds the following statement in reference 24Wolff, loc. cit. 25Brunner, op. cit., p. 378. 26 Wolfson and Fischer, op. cit., p. 181. 27Ibid. 28Brunner, op. cit., p. 373. 38 to the effect of otosclerosis upon the frame of the oval and round windows. '"I hold the opinion that there is an atrophic degeneration of cartilage which precedes actual otosclerosis."29 Air Conduction Deafness Due to Otosclerotic Growth Otosclerotic deafness of the air conductive type does not occur unless the foci affect the regions of the round or oval windows. In these instances the otosclerotic growth interferes with the transmission of sound waves to the auditory nerve. LindsayznuiHemenway explain the effect of the oto- sclerotic process involving the round window: if a small area of the round window membrane remains free the hearing will not be affected. occlusion of the round window could cause air con- duction loss comparable with that produced by stapes ankylosis.3O In cases where only the round window is affected, mobilization of the stapes is of no value, and therefore will be of little concern in this study. When the foci occur in the area of the oval window and grow through the annular ligament of the stapes foot- plate, partial or complete ankylosis of the footplate may result. Jackson and Coates state in reference to the oto- sclerotic foci growth in the oval window region: 291bid. “In 30J. R. Lindsay and W. G. Hemenway, "Occlusion of Round Window by Otosclerosis," The Laryngoscope, 64:18, January, 1954. w 39 With any marked new-bone formation in this area, involvement of the annular ligament and fusion of the stapes foot-plate must result. Unless this involve- ment and fusion take place, otosclerosis of the middle- ear type, the common clinical form of the disease, will not be present.31 Covell does not feel that fusion of the stapes foot- plate is inevitable if the foci appear in this region. However, he explains that even though ankylosis of the foot- plate does not result, loss of hearing is still possible. He says: A lesion which does not ankylose the stapes plate to the oval window margin may, however, impair the efficiency of the ossicles as a conducting mechanism. This is caused by the distortion in the oval window niche and interference with norm 1 function of the stapediovestibular articulation. Stapes ankylosis is of primary concern in this study - because it is this condition that may be alleviated by the stapes mobilization surgical procedure. Covell explains the stapes ankylosis phenomenon in the following manner: Otosclerosis which results in the fixation of the stapediovestibular joint impairs the mobility of the ossicular chain by displaggment_of the incudiostapedial and malleoincudal joints. The stapediovestibular joint is the connective area between the vestibule of the oval window and the stapes. The incudiostapedial joint is the connective area between the incus and the stapes, and the malleoincudal joint is the 31Jackson and Coates, op. cit., p. 10. 32W. P. Covell, "The Ossicles in Otosclerosis," Acta Oto-Laryngoscope, 28:275-276, June, 1940. 33Ibid. 40 connective area between the malleus and the incus. When the stapes is fixed, it becomes inactive, therefore causing the incus and malleus to become inactive. The ossicular chain becomes frozen and is ineffective in transmitting the sound waves to the inner ear. Etiology of Otosclerosis The author found that, to date, little proof has been found to transform the many hypotheses that have been pre- sented in regard to the origin of otosclerosis into reliable theories. In their book entitled, The Nose Throat and Ear and Their Diseases, published in 1930, Jackson and Coates state, "The numerous theories advanced as to the etiology of otosclerosis prove that not one is wholly satisfactory."3u In their discussion concerning possible treatment for otosclerosis, Wolfson and Fischer state in their book entitled, The Inner Ear, published in 1943: The basis for any rational treatment of a disease lies in the proper knowledge of its etiology. The complete lack of such knowledge in otosclerosis ex- plains the failurg of all the therapeutic measures applied hitherto. 5 Lindsay wrote in 1950, when discussing the etiology of otosclerosis: Attention has been directed to various diseases of glands of internal secretion, hormone inbalance, 3U’Jackson and Coates, op. cit., p. 504. 35Wolfson and Fischer, op. cit., p. 187. 41 vitamin deficiencies and metabolic disturbances but laboratory investigat%ons have so far revealed no specific connection.3 There have been many attempts to explain the origin of this disease in relation to other diseases. Wolfson and Fischer state: A study of the literature concerned with the etiology of otosclerosis reveals the amazing fact that only a few diseases exist that are not brought into relation with otosclerosis in the effect to explain is genesis.37 Theories that have been developed from these studies involving the relationship between diseases and otosclerosis do not appear to be totally accepted by most members in the field of otology. Perhaps this is due to the lack of suffi- cient proof or evidence to support them. Fowler states: "It is thought that its etiology may be hidden in some inherited factor."38 In regard to this hypothesis Lindsy found: Presence of a hereditary predisposition to oto- sclerosis has been in as high as 50 per cent of some large series of clinical cases. . . existence of heredity factor seems definite.39 36J. R. Lindsay, "Influence of Systemic and Local Factors on the Development of Otosclerosis," A.M.A. Archives pf Otolaryngology, 52:868, July-December, 1950. 37Wolfson and Fischer, op. cit., p. 181. 38Edmund Prince Fowler, "Emotional Factors in Oto— sclerosis," The Larypgoscope, 61:254, February, 1951. 39Lindsay, op. cit., p. 868. 42 Jackson and Coates observed that the results of a study undertaken to determine whether or not there was a heredity factor involved in the etiology of otosclerosis revealed: Over 50 per cent gave a family history of non— SIlepurative deafness, and like other conditions of a. Tieredity naturfi it tends to be transmitted through tides female line. 9 lKopetsky is of the opinion that there are inherited e1emer1t:s that could be the cause of later otosclerotic growth. He exp 1 ains: 'The congenitally deafened have carbohydrate metabolic nmacrhanism defects transmitted to them which develop oto— sc:lxerotic lesions on the otic capsule in intrauterine 1:11Pe, or they carry in their blood the biochemical EH11:hologic changes of otosclerosis which develop lesions alf1:er-birth, owing to the immediate etiohogic role which ari intercurrent irritant factor induces. 1 This author further states: It follows that any intercurrent severe systemic irlifection or the presence of puberty, pregnancy or menopause may present the locally irritant factor which will start a cellular pathologic condition 4 ‘1r11:o activity and create symptomatic otosclerosis. 2 Lindsay appears to agree with Kopetsky and reports that, "Existence of a hereditary predisposition has been indicélt:ed by clinical observations."'43 He mentions the f0110v¢fllng irritant factors: AOJackson and Coates, loc. cit. ‘alSamuel J. ertsky, "A Study of the Deafness Heritage in Otosclerosis," A.M.A. Archives 93 Otolaryngology, 52:416, JU1Y‘De cember, 1950. 43 Ibid., p. 403. Lindsay, op. cit., p. 880. 43 Certain constitutional states may furnish the en- vironmental influence necessary to activate the disease. . . . Prolonged terminal illness due to intracranial diseases may play an important role in starting the otosclerotic process in a subject possessing a hereditary tendency. . . . Environmental influence of prolonged constitutional disturbances and pregnancy is suggested by clinical observation. . Chronic inflammatory chaflges in the ear may act as environmental factors. That pregnancy is an irritant factor in the develop- ment of otosclerotic growth is generally accepted by most authorities who believe that the initialelement is inherited. However, Walsh lists the following common beliefs regarding pregnancy and otosclerosis, and states that evidence indicates that these beliefs are erroneous. Walsh reviews: (a) The deafness due to otosclerosis is made worse by pregnancy. (b) A woman with otosclerosis should be advised not to have children. (c) A woman with deaf- ness caused by otosclerosis can reasonably be advised to have a therapeutic abortion.u5 Barton appears not to completely accept the theory of pregnancy as an irritant factor in promoting otosclerotic growth. He does not advise abortion in pregnancy cases involving otosclerosis inherent in the prospective mother. He warns, "Abortion is never justified in management of .n46 otosclerosis. He further explains: Effect of pregnancy on otosclerosis is extremely variable and unpredictable and no exact relation exists ““1bid. 2+5Theodore E. Walsh, "Effect of Pregnancy on Deafness Due to Otosclerosis," Journal of American Medical Association, 154:1407, April 24, 1954. ‘— 46Richard T. Barton,'"The Influence of Pregnancy on Otosclerosis," NerEngland Journal of Medicine, 233:436, October 11, 19451 __'-_—“‘_—_ 44 between the two conditions. . . . Favorable effect of abortion on otosclerosis is inconstant; progression of deafness filth pregnancy may or may not be arrested by abortion. 7 To date, there does not seem to be any universal agreement among the authorities in the field of otology as to the specific etiology of otosclerosis. The author found the most accepted hypothesis to be that of there being an inherited element being activated by some irritant factor into progressive otosclerotic growth. Incidence. Little information was found revealing the incidencecfl‘otosclerosis. The information found appears to be quite general with little evidence to support the findings. For example, Fowler reports: It is markedly less prevalent in the Negro race, and less prigalent in males than in females, as far as we know. Nylen reveals the findings of a study he conducted involving the examination of 121 temporal bones: Otosclerosis was as common in men as in women in 121 temporal bones examined. . . women showed a greater tendency for stapes snkylosis. . . 90 per cent had foci in window regions. . . 40 per cent no stapes ankylosis . . . two thirds of the bones wiEh stapes ankylosis had foci in other areas as well. 9 47Ibid. uBFowler, op. cit., p. 254. 49Bengt Nylen, "Histophathologic Investigations on Localization, Number, Activity and Extent of Otosclerotic Foci," Acta Oto-Laryngology, 38:88, February, 1950. 45 Apparently otosclerosis affects the young as well as the adults. Kopetzky, in his study of deafness heritage in otosclerosis used subjects under 10 years of age. This study involved 25 deaf-mutes, l5 severely deafened children, and 25 children with serviceable hearing, but deafened. All showed symptoms of otosclerosis.50 II. HISTORY OF STAPES MOBILIZATION The surgical procedure of attacking the ankylosed area.of the stapes footplate through the auditory canal began in 1876 with Kessel. One technique practiced involved the removal of the eardrum, malleus, incus and leaving the stapes intact. The author found thatxmastotologists in the late eighteen hundreds used this method. Meurman and Meurman review the results of Laucae's successes using this technique, reported in 1885: In 53 cases operated on, considered improvement in hearing was obtained in 9, some improvement in 19, no improvement in 18 and deterioration of hearing in 7. Another technique used concerned the complete removal of the eardrum, malleus, incus and stapes. Brunner explains, "Extraction of the stapes results in the formation of a new 50Kopetzky, loc. cit. 51Meurman and Meurman, op. cit., p. 164. 46 membrane in the oval window."52 Therefore, if this method is successful the membrane in the oval window receives the sound vibrations directly without the aid of the eardrum or the bones of the ossicular chain. Brunner reports in regard to one operation of this type: In one of Blake's cases perilymph drained through the oval window for 10 days. Gradually the overflow of fluid and dizziness decreased, but the gain in hearin , which was noticed after the extraction was lost.5 The above mentioned techniques produced few favorable results. However, they led to the development of the stapes mobilization surgical procedure. This section of the study will concern the history of stapes mobilization, which began with Kessel in 1876; was discontinued in the early nineteen- hundreds in favor of the fenestration operation; and was rediscovered by Rosen in 1952. Kessel Schneider reports that, "Mobilization of the stapes began with Kassel in 1876, who first advised it."54 This was before the true nature of otosclerosis was known. At this time otosclerosis was considered to be a dry sclerosis of the middle—ear-mucosa.55 53lbid., p. 19. 54Danial C. Schneider, "Revision of the Miot Technique in Moblization of the Ossicle System," A.M.A. Archives pf Otolaryngology, 61:207, January-June, 1955. 55Meurman and Meurman, loc. cit. Rosen and Bergman state in reference to Kessel's endeavor: Kessel, in 1876, tried improving hearing in cases of stapes ankylosis by removing the drum membrane, malleus, and incus. Later he tried mobilization and complete removal of the stapes . . . all unsuccessful.56 Brunner reviews Kessel's attempts at stapes mobili- zation in the following manner: The favorable results of experimental extraction of the stapes encouraged Kessel to mobilize the stapes in cases of conductive deafness by removing adhesions from the niche of the oval window and cutting the tendon of the stapedius muscle. Since final results were unfavorable it was replaced by extration of the stapes.57 The next man to be considered in the history of stapes mobilization is Boucheron. Rosen and Bergman state that Bourcheron reported in 1888, mobilization of the_ stapes in 60 cases. He first excised the posterior half of the drum and then separated the incus from the stapes.58 Meurman and Meurman describe Boucheron's technique as using a special hook to mobilize the stapes in the oval window, after he first separated the incus and the stapes from each other. These authors state that he did obtain some good results. However, the favorability of such 59 results were not reported. 56Samuel Rosen and Moe Bergman, "Mobilization of the Stapes for Otosclerotic Deafness," A.M.A. Archives pf Oto- laryngology, 61:197, January-June, 1955. 57Brunner, op. cit., p. 18. 58Rosen and Bergman, op. cit., p. 197 59Meurman and Meurman, op. cit. 48 Schneider reports that Boucheron was enthusiastic about stapes mobilization. He says: Boucheron stated it was possible to quadruple a patient‘s hearing by this method. He hailed stgpes mobilization as, "Our operation of the future." Miot Schneider states that, "In 1890, otosclerosis was brought to a high state of development by Camille Miot."61 Meltzer feels that Miot should receive the real credit for enlightening the otologists of that period about stapes mobilization. Meltzer explains: With the exception of modern incisions to expose the typanum he described with infinite detail the as? warm senseless, , . The author could find little information concerning Miot's technique or his personal description of the operation. However, Scheer reports: Miot described in fair detail his technique of applying pressure by a palate-like instrument on the incudostapedial joint.6 6OSchneider, op. cit., 61lbid. _ 62Symposium, "Operation for the Mobilization of the Stapes in Otosclerotic Deafness," The Laryngosque, 66:730, July, 1956. 63Alan Austin Scheer, "Restoration of Hearing in Otosclerosis by Transtympanic Mobilization of the Stapes," A.M.A. Archives pf Otolarynogology, 61:513, January-June, 1955. 49 In reference to Miot's technique Schneider explains: Miot had exerted force only in the direction per- pendicular to the line of the ossicular movement. He used a backward and downward pull to "break" the ankylosis . . . he pullegubackward in the direction of the stapedial tendon. According to Schneider,Miot experienced 74 good results in 126 cases involving stapes mobilization.65 Meurman and Meurman report that Miot obtained satisfactory improvement in 28 cases out of 56.66 Rosen and Bergman report that Miot obtained slight and only temporary improve- ment among 200 cases.67 These authors did not state what was considered at that time to be good, satisfactory, slight or temporary results. Although confusion exists concerning the degree of Miot's stapes mobilization successes, all of the above mentioned otologists agree that he did obtain some success. It is also mentioned by Rosen and Bergman that Miot had operated on the same ear in some cases, three times within the first three months.68 64Schneider, op. cit., p. 209. 65Ibid.,p.207. 66Meurman and Meurman, loc. cit. 67 , Rosen and Bergman, op. cit., p. 197. Ibid. 50 Blake Little information was found concerning the success of Dr. Clarence Blake's attempts at stapes mobilization. However, some of his attitudes towards stapes mobilization, and the technique of the removal of the drum, malleus and incus are reviewed. Blake reported in 1892, his feeling toward the removal of the eardrum, malleus and incus: The removal of the membrana tympani, malleus and incus not only offers an unnecessary degree of violence to the middle ear but is unscientific in the sense that it leaves untouched that portion of the ossicular chain, the stapes, which has beSn justly demoninated the key to the labyrinth. Blake explains the reported successes with this tech- nique by saying: The improvement in hearing in the cases so operated upon has been due in the great majority of them to the mobilization of the stapes incident to the removal of the two larger ossicles rather than to the removal of an obstruction presented by these bones themselves . . unless the stapes itself be mobile removal of the membrana tympani and the other ossicula must be in a measure ineffectual. This author reports the degree of success he obtained with one of his early attempts at stapes mobilization: In Oct., 1881, it was decided to attempt mobili- zation of the stapes with a result of slight improve- ment in hearing aerially, which lasted for three days and then gradually decreased. 7OClarence J. Blake, "Operation for Removal of the Stapes," Bogton Medical and Surgical Journal, 127:470, 1892. 71Ibid. 72Clarence J. Blake, "Operation for Removal of the Stapes without Ether," Boston Medical and Surgical Journal, 132:35: 1895. 51 Whether or not Blake actually practiced stapes mobili- zation to any extent or remained exclusively with the old techniques was not discovered by the author. Jack Meltzer bestows upon Jack the credit for the intro- duction of stapes mobilization into the United States. He states: I In this country it had its inception at the insti- tution where I had my otological training; in fact, it was under the very man who in 1892 introduced 73 stapes mobilization, namely Dr. Frederic L. Jack.. Jack appears to agree with Blake concerining the omprovement in hearing after the eardrum, malleus, and incus are removed. He explains in an article he wrote in 1895: From our present knowledge it seems plausible to attribute the improvement in any individual case, of removal of the membrana tympani, malleus or incus, in part or whole, chiefly to liberating or mobilizing the stapes.( It appears that during that period the two primary operations practiced by otologists were the removal of the stapes, and stapes mobilization. Jack reports: The interest in operations for the relief of deafness, vertigo and tinnitus has naturally centered during the last two years, upon mobilization or removal of the stapes. 73Symposium, loc. cit. 74Frederick L. Jack, "Remarks on Stapedectomy," Boston Medical and Surgical Journal, 132:35, 1895, 75Ibid. 52 Jack advocates the use of cocaine while performing the stapes mobilization operation. He felt that cocaine will allow the patient to give aid in determining the operation's progress. In this way the patient can respond if the hearing isimproved.76 Brunner says that Jack used a set of magnification lenses to perform the operation.77 No information was found in regard to the degree of Jack's successes or failures. .However, Jack explains: My results in so-called cases of sclerosis have been extremely discouraging,for in nearly every instance the bone has been found so firmly ankylosed, usually in the neighborhood of the foot-place, that upon pressure a fracture of the cura hag occurred, leaving the footplate firmly adherent.7 Jack states that, "Most operations for mobilizing the stapes or freeing the oval window must be looked upon as largely experimental.“79 However, he adds: In cases of non-suppurative diseases of the middle ear, surgical mobilization should first be trieg before an attempt is made to remove the stapes. O Sibenmann Sibenmann is included here, not because of his experi- ence with stapes mobilization, but because of a statement he made that seems to reflect the feeling among many otologists 76 77 Ibid. Brunner, op. cit., p. 19. cit 79 78Jack, op. . Ibid. 80Ibid. 53 of the early nineteen-hundreds. In 1900 Sibenmann stated, '"All endeavors at mobilization of the stapes are not only useless but often harmful." Stapes Mobilization Discontinued Attemps at stapes mobilization were generally dis- continued during the early nineteen-hundreds. Meltzer answers the question as to why stapes mobilization was given up, "Why? I can only venture a guess. It failed; hearing was not lastingly improved."82 Rosen and Bergman state that one reason for stapes mobilization failures at this time might be because: In all these operations the attempt to mobilize the stapes was through a myringotomy (incision in the eardrum). It may be that in many cases myringotomy did not provide sufficient vigion of the stapes to allow precise manipulation. 3 The Advent of Fenestration Further exploration into stapes mobilization ceased after the introduction of a new technique to alleviate hearing loss due to stapes ankylosis. This technique con— cerns the creation of a new window in the labyrinth after by-passing the fixed stapes. This new window is made in the area of the semi—circular canals. The fenestration 81 82 Schneider, loc. cit. Symposium, op. cit.,p.73l. 3Samuel Rosen and Moe Bergman, "Restoration of Hearing in Otosclerosis by Mobilization of the Fixed Stapedial Footplate. An Analysis of Results," The Laryngoscope, 65:224, April, 1955. 54 operation will be discussed in the following section of this study. The basic idea of the fenestration operation began with Holmgren. Stevenson explains: In 1917, Holmgren, of Stockholm, began the researches in the surgery of the labyrinth which he continued with varying success over many years. influencing Sourdille, Simson Hall and others. To Maurice Sourdille, of Nantes, must be given credit of devising the first successful fenestration for otosclerosis . . . Julius Lempert of New York, in 1938 developed Sourgille's operation into a practicable procedure. It was Lempert who termed this procedure the fenes- tration operation.85 From Holmgren up to Rosen, fenestration had taken over the limelight. The operations directed through the auditory canal against the ossicular chain and the alkylosed area of the stapes footplate received little attention. Holmgren Schneider reports that in 1923, Holmgren experienced some success with stapes mobilization. However, it was not intentional on Holmgren's part. He was performing a routine pre-fenestration examination on one of his patients. During this examination Schneider explains, "He accidentally twisted the stapes in such a way that the oval window was 84Stevenson, op. cit., p. 110. 85Ibid. 55 opened."86 Holmgren then gave the patient an immediate hearing test. The test revealed an improvement in hearing.87 This author reviews Holmgren's explanation of why twisting the stapes may be advantageous in stapes mobili- zation: 'I‘he stapes normally does not simply move "back and forth, "it also moves, being the end-plate of 88 an oscillating acoustic system, in a rotary fashion. Schneider adds, "Great caution must be observed, as Holmgren reported, it is possible to dislocate the stapes."89 The author found no further information regarding Holmgren's other experiences with stapes mobilization, if there were any. Herbert s Meurman and Meurman quote Dr. Herberts as saying in 1947, " The time is ripe for new attempts in the area of the stapes. H 90 However, Herbert's interest was placed primarily upon Stapedectomy. Meurman and Meurman describe Herbert's en- deavors: After demonstration on cadaver material that the membr‘ane covering the inner surface of the stapedial fOOtp late is thicker than usual in otosclerosis, he exPOSed the middle ear in two patients through the \_ Schneider, op’. cit., p. 209. 87Ibid. 8 8Ibi‘d‘. 89Ibid. 9 3Meurman and Meurman, loc. cit. 56 process and removed the stapes leaving the membrane in site. These authors mention that Herbert's results were good, but it is unknown whether or not they were permanent .92 Rosen IMeltzer says, "To Rosen must go the credit of re- discovery of stapes mobilization."93 Dr. Samuel Rosen, like Holmgren, accidentally mobilized the stapes in one of his fenestration patients. In this respec t , Rosen and Bergman explain: On April 3, 1952, Rosen was performing a procedure on a patient described as a method of palpating the stapes as a means of determining suitability for fenestration. . . . Result, a return of acute hearing. . . The footplate was accidentally mobilized while the fixed stapes was being palpatated. 9 Since Rosen's rediscovery, stapes mobilization has generated new interest and enthusiasm in the field of otology. Goodhill states, ". . . Rosen rewakened our inter- est in the direst approack to the ankylosed stapes foot- plate."95 Meltzer says, "Rosen's recent technique has definitely given otologists a new enthusiasm."96 It has also motivated some adverse criticism because or its eEirlier failures. In this respect Meltzer reasons: \ 9 lIbid. 92Ibid. 93Symposium, loc. cit. 9)413osen and Bergman, o . cit., p. 224. 9t5C+oodhill, op. cit., p. 333. 96Symposium, loc. cit. 57 What difference does it make what these early results were? Does it matter if three or four patients are improved by stapes mobilization in ten attempts? Are not three or four successes a real attainment? Given time and experience and under- standing as to why we fail, should we not expect better results just as we improve our results with the fenestration operation? I believe so. He adds: The hearing improvement brought about by stapes mobilization is of such magnitude that I confidently look forward to its becoming as firmly established a procedure for the improvement of hearing én oto- sclerosis as the fenestration operation.9 It seems that Dr. J. H. Thomas Rambo views Rosen's re—awakening of stapes mobilization primarily from the standpoint of the method of attack. That is, the attack made directly upon the area of the ankylosed footplate and the oval window, through the auditory canal. Rambo explains: I believe that experience with the footplate approach in mobilization techniques is leading us inevitably to the recognition that hearing through even a small opening at the oval window is a much more physiological way for airborne sound to mobilize inner ear fluids; and we are, therefore, getting surprising good results when sound reaches the inner ear through this natural route, even without the ossicular chain.9 Rambo summarizes by saying: today we-have been reminded by several of the participants that mobilization is not a standard procedure; that there are many techniques used; and that we are all looking for a special procedure which will offer a better solution to this surgery. I imagine that approximately the same situation probably existed following Miot's experiences with mobilization which prompted Jack in Boston after repeating them, to perform stapedectomy.lOd 971bid. 98Ibid. 99Ibid., p. 781. lOOIbid.,p.782. 58 If such be the case, that we continue to follow faith— fully the experiences of the otologists of over half a century ago, which we have done so far, we will again arrive full-circle to stapedectomy.lOl Whether or not Dr. Rambo's above mentioned prediction is correct naturally remains to be seen in the future. How- ever, many otologists in this country and other countries are practicing stapes mobilization, and to date, there appears to be a great deal of enthusiasm in regard to its possibilities. III. FENESTRATION OPERATION Today, there are but two surgical procedures commonly practiced by otologists for the possible alleviation of deafness due to stapes ankylosis. These procedures are the fenestration operation and stapes mobilization. The primary differences between the two operations concern the method of attack and the degree of simplicity in regard to the surgical procedures. Criteria for the selection of candidates is basically the same. It was mentioned earlier in this study that Holmgren, Sourdille, and Lempert are the principle otologists respon- sible for the development of the fenestration operation. In 1916, Holmgren introduced the method, Sourdille developed it further, and Lempert perfected the operation and gave it its name. Farrior and Bagby state that today, "All lolibid. ~a£z I -_. -- 59 fenestration operations are Lempert fenestration opera- tions."102 However, they mention that some otologists have added their own individual techniques to various phases of the procedure.103 This section of the study will include a discussion of fenestration in regard to the selection of prospective candidates, the objectives of fenestration, the operation itself, the results of fenestration, the causes of fenes- tration failures and post-operative complications. The author feels that such a discussion is pertinent to this study in order that the reader may understand the advantages and disadvantages of stapes mobilization more effectively by comparison with those of the fenestration operation. Pure—Tone Audiometric Testing In discussing the criteria for the selection of fenestration candidates and for determining operation suc— cess, it will be necessary to use such terms aS'"decibel," '"audiogram," "aid conduction,‘ and "bone conduction." These terms are primarily related to the testing of hearing by the pure-tone audiometric method. An explanation of such terms is of value at this point. There are various methods employed for testing an individual's degree of hearing loss due to otosclerosis. 102J. Brown Farrior, Richard Bagby, and Cecil Thomas, "Fenestration Operation Analyzied for Nonfenestrating Otologist," A.MtA, Archives pf Otolaryngplogy, 59:7,Jan.1954. lo31bid. la 60 One series of tests involves the use of tuning forks. Other types of tests employed are the speech reception threshold and speech discrimination tests. All of these tests of hearing and their relationship to the testing of otosclerotic severity will be discussed in Chapter IV of this study. However, the author feels that an explanation of pure-tone audiometric testing and its terms will be adequate for this section of the study. Pure-tone audiometer. A pure-tone audiometer is an electrical instrument used for measuring the degree of hearing existing within an individual. Saltzman states that an audiometer is: . . . calibrated for a frequency range of 64 d.v. to about 10,000 d.v., or more and is capable through an attenuator . . . to deliver sound in steps of 5 db. to the intensity level of 100 db. or higher. The "zero line" is the no loss line which signifies average normal hearing, while the -5 and -10 lines represent degrees of acuity of hearing that excel the average as far as the threshold level is ooncerneleLl The decibel. Hearing losses are measured in decibels. Stevenson defines a decibel in the following manner: an arbitrary unit of sound intensity, which expresses the ratio of the acoustic energy required to stimulate a given ear at a given frequency to the acoustic energy found by a large number of investi- gations to constitute the threshold for the normal ear at this frequency.10 lO“Maurice Saltzman, Clinical Audiology (New York: Grune and Stratton, 1949), p. 152. 105Stevenson, op; cit., p. 37. 61 The audiogram. An audiogram is a graphic record used for recording the information measured by an audiometer. Generally speaking, an audiogram consists of a series of horizontal lines crossed by a series of vertical lines. The horizontal lines designate the intensity measurements, and are labeled in the following order, ~10 db, -5 db, 0 db, 5 db, 10 db, 15 db, and on up to 100 db. The vertical lines indicate the frequencies. They are generally labeled in the following manner, 64, 128, 256, 512, 1024, 2048, 4096, and 8192. Air conduction and bone conduction. Air conduction is a term meaning the transmission of sound waves through the external ear canal, the middle ear, to the inner ear. Bone conduction is a term meaning the transmission of sound waves through the temporal bones of the skull to the fluids of the inner ear. For air conduction testing regular earphones are worn by the individual being tested. When testing by bone con- duction an oscillating unit is worn usually on the mastoid bone behind the auricle. Selection of Prospective Candidates for Fenestration Not all persons suffering from a hearing loss due to otosclerosis can benefit from the fenestration operation. However, Farrior states: 62 In the ideal candidate with the ideal fenestration operation the patient should always rpggive a maximum and permanent restoration of hearing. Basically, if the otosclerotic bone growth has done extensive damage to the cochlear nerve, fenestration will be of little value. It is the individual with impaired hearing due to stapes ankylosis, but whose cochlear nerve is unaffected by the bone growth that may best benefit from this operation. Farrior offers the following definition of the ideal fenestration candidate: The ideal candidate for the fenestration operation is the otosclerotic patient with a flat ascending air conduction audiogram with a 40 to 60 decibel hearing loss for the speech frequencies and normal bone con- duction.lO The interpretation of this audiogram reveals that there is considerable air conductive loss, and that because of the normal bone conduction, the cochlear nerve is un- affected. It should be mentioned here that the speech frequen- cies are those frequencies important to the comprehending of normal speech. On an audiogram these frequencies are 512, 1024, and 2048. If the hearing loss at these frequencies is greater than 30 db, an individual will not have adequate hearing to communicate effectively in society. 106J. Brown Farrior, "The Fenestration Operation in the Ideal Candidate," The Laryngoscppe, 64:414, May, 1954. 107Ibid. 63 Walsh and Silverman state in regard to the require- ments for prospective fenestration candidates, a patient: 1. who is young between adolescence and forty- five years of age . . . 2. who has a progressive loss of hearing». . . 3. whose air conduction curve on audiometry is generally flat or rising in the high tones, and, . . . 4. whose bone conductive loss is not more than 20 db from 200 to 4000, presents an ideal case.108 These authors add,'"We would, however, disagree with rigid adherence to these criteria.“109 They feel that age is important only as far as the patient's response to trauma and his ability to heal is concerned. Ferrior classifies fenestration candidates into the following three categories: Good Candidate: . . . hearing for speech frequencies of 512, 1024 and 2048 below the critical level of 30 db. The bone conduction is normal for speech fre- quencies. Fair Candidate: . . . more severe loss of auditory acuIty for the higher tone frequencies indicating loss of cochlear nerve. Bone conduction is still normal at 512, slight loss at 1024, but at this frequency bond conduction has not fallen below 20 db. level. Bone conduction for 2048 is near 30 db. Poor Candidate: Bone conduction is normal at 512. At 1024 bone cdfiduction is below the critical level 110 of 20 db. and bone conduction is below 30 db. at 2048. Jones discusses the various fenestration candidates in the following manner: lOBTheodore E. Walsh and 3. Richard Silverman, "Diag- nosis and Evaluation of Fenestration." The Laryngoscope, 56: 538, September, 1946. 109Ibid. 110J. Brown Farrior, "The Fenestration Operation- Indications, Technique and Result," The Laryngoscgpe, 59: 516-517: May, 19490 64 1. Ideal cases, comparatively rare. . . 2. A good risk, is satisfactory and common. . . 3. A poor risk, the few who have a chance to recover some hearing. . . 4. Unsatisfactory,occasionally, operated on after a thorough explanation to the patient, fol- lowed by a period of three months for consideration.111 Pure-tone audiometric testing is not the only method used in selecting candidates for the fenestration operation. In fact, some otologists place little confidence in the results obtained from audiometric bone conduction results for determining the state of the cochlear nerve. Reasons for this, and other methods of testing for cochlear nerve damage will be discussed in the following chapter. Objectives of Fenestration Basically, the principal objective of the fenes- tration operation is to create, a new window within the horizontal (external) semi-circular canal to compensate for the occluded oval window. If this procedure is successful, sound waves that are collected by the auricle, will be directed to this new window by passing through a newly created cavity within the mastoid bone. These sound waves will strike an artifi- cial membrane that is placed over the new window, and innervate the inner ear fluids, which will in turn innervate the cochlear nerve. lllMarvin F. Jones, "Critical Survey of the Lempert Endural Fenestration Operation," The Laryngoscopg, 57:263- 264, March, 1947. 65 The artificial membrane is constructed from the thin epithelium that lines the external auditory meatus, however, otologists have experimented using other tissues. A successful fenestration operation restores some of the patient's hearing by air conduction, although air- born sounds by-pass the normal ossicular chain acoustic route. Lempert says, " the normally functioning ossicular chain channels 30 times the pressure of sound from the tympanic cavity to the perilymph and endolymph."112 In cases of stapes ankylosis he adds,'"A newly created fenestra in the external semicircular canal . . . channels approximately 30 to 100 times the sound of pressure of the . . . func- tionally impeded, ossicular chain."113 Lempert lists the following three objectives of fenestration surgery: Objective l.-The primary objective of creating a new fenestra is to render the perilymph and endolymph freely mobilizable by normal air-borne sound. . . . Objective 2.-The second objective is to permit normally tolerated air-borne sound to do the mobilizing of the perilymph and endolympth. Objective 3.-The third objective is to reconstruct the middle ear surgically so that it would permit the mobilization of the cochlear fluids by air-borne sound energy through both the new vestibule fenestra and nature's cochlear fenestra (round wifldow) under the most favorable phase relationship. 112Juluis Lempert,'"Physiology of Hearing," A.M.A. Archives pf Otolarynogology, 56:104, August, 1952. 113Ibid. 114Ibid., p. 105-108. * 66 In analyzing the article within which Lempert states these three objectives it seems that his means to these ends are as follows. In regard to Objective 1, he found that the new window must be placed within the external semicircular canal. If placed within the cochlear promontary instead of the external semicircular canal, remobilization of the inner ear fluids will not be accomplished. In reference to Objective 2, he feels that in order that the best possible mobilization of the inner ear fluids is accomplished, the tympanomeatal membrane sealing the new window must be, '". . . flexible and readily yielding."115 Concerning Ob- jective 3, he found that it is important that the tympanic membrane be kept intact so that it hermetically seals the tympanic air space. He states that this is important so that the proper difference in phase or intensity relation- ship of the sound pressure exerted on the vestibular and cochlear windows be accomplished.116 Fenestration Operation Procedure It has been stated that there are two basic differ- ences between the fenestration operation and stapes mobili- zation. In fenestration the method of attach differs from stapes mobilization in that it is not directed against the ankylosed area of the footplate, but it by-passes this area. In regards to the other difference, fenestration is a more complicated procedure. 115Ibid., 106. 116Ibid., 105—108. 67 According to Sullivan and Smith the operation is performed under either a local or general anesthesia.117 Farrior and Bagby describe the initial incision as a crescentric incision at the inner depth of the cartilagin- ous canal. The point of this incision is within the posterior wall of the external auditory meatus where the cartilage meets the bony portion. The flap that is created by this 118 Sullivan incision is elevated before bone surgery begins. and Smith explain that the flap is then covered by a paraffin gauze to protect it from the mechanical burr that is used for bone surgery, and possible bone chips.119 The next procedure concerns the creation of the new cavity. When completed, this cavity provides an acoustic route from the outer afl1*through the bone encasing the external auditory canal, the mastoid bone and to the horizon- tal semi—circular canal. At one phase of this procedure the incus and the head of the malleus are exposed. These portions of the ossicular chain are removed. The final step in the creation of the cavity is explained by Sullivan and Smith: Using a diamond burr, the posterior canal wall over the facial nerve is lowered still further and the bone cells around the superior, horizontal and posterior semicircular canals are removed. . . . This latter procedure is carried out with magnifying glasses so that the facial nerve may be discerned. 2 117Wiener and others (eds.), OE. Cit-: p. 409- 118Farrior, Bagby, and Thomas, op. cit., p. 6. 120 119Wiener and others (eds.), loc. cit. Ibid. 68 These authors further explain that after the semi- circular canal is exposed, the stapes is tested for its mobility.121 According to Rosen palpation of the stapes could be useful in determining for which cases of otosclero— sis that fenestration should or should not be done. This author states: One cannot determine with absolute certainty if the stapes is completely fixed by any method except palpation of it with a probe during the fenestration operation. . . . A completely fixed stapes is patho- gnomonic (indicative) of an otosclerotic condition which is ideal for treatment. . . . The fenestration operation should therefore be performed on patients with compéetely fixed stapes to insure the best results. 2 Sullivan and Smith state that the next step is admin- istered through a dissecting microscope using the diamond and finishing burrs. It involves the creation of the new whmiow within the horizontal semi-circular canal. These authors state, "Opposite the oval window, the fenestra is made on top of this dome by grooving the endosteal bone which is removed as a lid'."123 They further explain that this exposes the membranous duct and the endosteal membrane (lining of the labyrinth).124 Farrior says,‘The cutaneous lining of the anterior wall of the canal provides the thinness possible covering 121Ibid. 122Samuel Rosen, "Palpation of Stapes for Fixation," A.M.A. Archives pf Otolaryngology, 56:610, December, 1952. 124 123Wiener and others (eds.), op. cit. Ibid. 69 for the fenestra."125 This lining is a portion of the flap created by the initial incision. Sullivan and Smith explain that this covering is held in place over the fenestral rim by two or three paraffin mesh packs, which are later removed.126 Fenestration Results Jones states in regard to the results of fenestration: Fenestration operation sometimes results in normal hearing, but the usual improvement falls in the zone between 15 db. and 25 db. loss. This is a useful hearing level, but it is not norma1.127 Farrior, Bagby, and Thomas feeltfluuzif the patient has a good bone conduction prior to the operation he will obtain, ".A. . a gratifying restoration of hearing. . . will last in more than 95% Of cases."128 He further implies that the restored hearing will be permanent provided the fenestra and flap and microscopically perfect. This author says: While initial result is primarily dependent upon the quality of bone conduction . . .the permanent result is primarily dependent upon the quality of the surgery. 9 Jones believes that a satisfactory operation depends upon the following criteria: 125Farrior, "The Fenestration Operation-Indications, Technique and Result," op. cit., p. 252. 126Wiener and others (eds.), op. cit. l27Jones, op. cit., p. 268. 128Farrior, Bagby and Thomas. op. cit., p. l. 129%. 7O Pure-tones in the conversational range, (512, 1024, and 2,048) must all have better than a 0 db. loss in order to be classified as satisfactory. In regard to the amount of time required to determine the permanency of such results, Jones is of the opinion that one year is reasonable and two years are safe. If the restored hearing has lasted two years, Jones feels that the hearing is permanently improved. He further states that if any surgeon has attained 60% permanent improvement in his fenestration operations, he is getting excellent results.131 Sullivan and Smith explain why a hearing improvement of 30 db. or better is the best result that can be expected from the fenestration operation: . hearing at the 0 db. level is almost impossible since the normal mechanics of hearing are interfered with. It is a makeshift but ingenious operation. Nature supplied us with middle ear bones to concentrate the sound into a little window which we initiate in size in the horizontal canal, but it will not be possible to obtain the gain in volume until some mechanical device or other improvement is devised.132 Causes of Fenestration Failures According to Jones, "Fenestration is not a 100% effec- tive operation. We do have failures."133 He says that the three most common causes for failure are, a bony regrowth which closes the newly created window, wrong diagnosis, and 134 surgical accidents. 130 Jones, op. cit., p. 270. 131Ibid. l32Wiener and others (eds.), op. cit., p. 414. 133Jones, op. cit., p. 209. 134Ibid. l: 71 In regard to surgical accidents Jones states: Motor driven instruments, vagaries of electrical equipment, mechanical defects in instruments, and just plain slips have been the cause of failures. I might also add they will probably continue to cause failures. When a r0tating burr tangles with a deli- cate and carefully made membrane and flap, the damage is done. When the adjustment on electrical devices is accidentally altered or a "short" occurs, damage may be done. When a defective instrument breaks, the gods of chance control the outcome. When some entheusiastic observer bumps the surgeon's arm while he is using a suction nearlgpe fenestration, the only thing left to do is swear. Post-Operative Complications Jones states, ”A discharging ear has proven to be the most annoying post-operation feature with which I have had to deal.“136 Farrior and Bagby believe that, "Chronic dis- charge is one of the greatest nuisance factors in fenes- tration surgery."137 Such post-operative discharges are generally caused by inflammation of the newly created cavity 138 walls. Farrior and Bagby state that, "The fenestration operation leaves a denuded area of 5 to 8 sq. cm. It takes time for this area to heal, but eventually it almost always does heal.“139 Another complicating post-operative factor is that of labyrinthitis (inflammation of the labyrinth). Farrior and Bagby describe the three phases of labyrinthitis: 1351bid. 136Ibid., p. 267. 137Farrior, Bagby and Thomas, op. cit., p. 11. 138Ib1d; 139Ibid. 72 1. Primary surgical labyrinthitis . . . immediate effect of surgical injury or hemmorrhage is demonstrable on the first post—operative day. 2. Secondary serious labyrinthitis . . . results of inflammatory response, reaches its peak on the fifth to tenth day. 3. Tertiary degenerative labyrinthitis . . . the end result. Loss of high tonefi is the mildest form, and nerve deafness the severe.1 0 If the facial nerve is severed during the creation of the cavity, facial paralysis will result.lb'l However, in this respect Farrior and Bagby state, “Such an accident might occur, but par for facial paralysis should be zero."142 Vertigo is another possible result of the fenestration operation. Farrior and Bagby say, "Lasting vertigo is regis- tered as a complaint by a small percentage of fenestration patients."143 After the operation the fenestration patient remains under the care of an otologist. Farrior, Bagby and Thomas explain: Postoperatively, when a patient returns to the care of his referring otologist, we ask him to consult this physician once a week for three weeks, one a month for three months, and three times a year thereafter. The purposes of these visits are cleansing the cavity and removal of any crust.144 14 14 14 1Ibid. '2Ibid., p. 10. 143Ibid. 11mIbid. OIbido , ppo 9-10. CHAPTER IV PREOPERATIVE AUDIOMETRIC TESTING The various techniques of audiometric testing used in the preoperative diagnosis of stapes ankylosis, and the selection of prospective candidates for the stapes mobiliza- tion surgical procedure will be considered within this chapter. As an aid in diagnosis, autiometric testing is employed to determine whether or not a conductive hearing loss is present, whether or not this loss is caused by stapes ankylosis, and whether or not the condition is com- plicated by a cochlear nerve impairment. Audiometric testing is also emp10yed in the selection of prospective stapes mobilization candidates. By revealing the severity and characteristics of a hearing loss due to stapes ankylosis, audiometric testing can aid the otologist in selecting affected individuals who may best benefit from surgery. Myers and Ronis offer the following information re- garding the preoperative value of audiometric testing: The diagnosis of otosclerosis can be made . audiometrically. The degree of stapes fixation cannot be predicted by the preoperative audiologic survey. At the present time, the successful 74 candidate cannot be predicted preoperatively. The amount of hearing improvement cannot be predicted preoperatively.l It appears that Bergman contradicts Myers and Ronis on their last two points regarding the value of preoperative audiometric testing. Bergman states that with adequate audiometric testing the otologist: can evaluate the preoperative hearing function in all its aspects . . . can predict the amount and kind of hearing gain which can be obtained from suc- cessful surgery. . . and can determine the goal of the operation for each patient. The belief that the degree of stapes fixation cannot definitely be determined preoperatively is supported by most ‘otologists reviewed by the author. Due to the limitations of present day audiometric testing methods, the severity of stapes ankylosis can only be ascertained after an entrance has been made into the tympanic cavity. Because of this, it would seem that Myers' and Ronis‘ opinions that a suc- cessful candidate cannot be predicted preoperatively nor can the amount of hearing improvement be predicated pre— operatively, are most plausible. However, audiometric testing can aid the otologist in choosing affected individuals who may best benefit from stapes mobilization. Goals may be set with the aid of 1David Myers and Bernard J. Ronis, "Improvement of Hearing in Otosclerosis by Means of Stapes Moblization Operation," A.M.A. Archives pf Otolaryngplogy, 64:308, Dec— ember, 1956. aMoe Bergman, "Audiologic Aspects of Audiosurgery," AWM.A. Archives pf Otolaryngology , 63:280, March, 1956- 75 audiometric testing, but the accurate prediction of such goals is difficult because of the above mentioned unknown factors. According to Bergman: The assessment of hearing function prior to surgery should be intensive and extensive . . . . Because of the limitations of tests currently in use it is nec- cessary frequently to employ a variety of tests, to reduce doubts about the suitability of a patient for the operation and to develop realistic goals for the treatment.3 Audiometric tests used in the diagnosis of stapes mobilization are pure-tone audiometric tests (both air conduction and bone conduction), tuning fork tests and monitored speech reception tests. It seems apparent to the author, after reviewing the material concerning the subject, that only the results obtained from pure-tone and speech reception tests are used extensively in selecting prospec- tive candidates and determining post-operative results that might be gained through successful surgery. I. PURE-TONE AUDIOMETRIC TESTING Pure-tone audiometric testing has been discussed previously in Section III, Chapter III, of this study. It was explained in relation to the selection of prospective candidates for the fenestration operation. However, the method of administering a pure—tone audiometric test was 3Ibid. 76 not considered. Within this section of the study the method of administration will be explained, along with the value of pure-tone audiometry in the diagnosis of stapes ankylosis and in the selection of candidates for the stapes mobilization surgical procedure. The Administration of Pure-Tone Audiometric Tests The audiologist can test an individual's hearing by either air conduction or bone conduction with a pure-tone audiometer. The administration of air conduction and bone con- duction tests are basically the same. The difference lies in the type of receiver worn by the individual being tested. It was previously stated in Section III, Chapter III, that in air conduction testing the individual being tested wears a regular air conduction earphone, while in bone conduction testing an oscillating unit is worn on the mastoid bone behind the ear. It is the purpose of pure-tone testing to obtain an individual's "threshold" for each of the following frequen- cies in cycles per second: 128, 256, 512, 1024, 2048, 4096, and 8196. In some audiometers these frequencies in cycles per second are represented in round numbers in the following manner, 125, 250, 500,1000, 2000, 4000, 6000, and 8000. The term'"threshold" is explained by Saltzman: By means of the modern audiometer, it became possible to standardize the least amount of sound 77 power necessary to arouse an auditory sensation in a normal ear, and the term'"threshold" has been adopted to designate this point.l‘L To obtain these thresholds of hearing for the various frequencies the audiologist explores each frequency by introducing it into the air or bone receiver at different intensities. The audiologist is able to regulate the trans- mission of frequencies by manipulating a "tone interrupter" located on the audiometer panel. He is able to choose the frequencies to be transmitted and their intensities, by ad- justing two dials on the audiometer panel. One dial selects the frequency to be transmitted and the other*dial selects the intensity of the frequency. During the test the individual being tested is seated so that he cannot see the movements of the audiologist mani- pulating the "tone interrupter." Therefore, if the audiolo- gist has an effective technique and does not follow a rhythmic pattern of tone transmission, the individual being tested is aware of the tone transmission only when hearing it. In order that realistic thresholds may be obtained, it is necessary that the audiometer be properly calibrated and the test be performed in an acoustic environment free from disturbing noise. The individual being tested signals when he hears the tone. When hiS‘"threshold" for a given frequency has “Saltzman, op. cit., p. l. 78 been reached the audiologist records the finding on the audiogram and proceeds to another frequency. This method of recording the'"thresholds" on the audiogram involves the use of symbols. Generally, the symbols used in recording right ear thresholds are "0" (in red) for air conduction and'" ‘" (in red) for bone conduction. Those used for left ear thresholds are "X" (in blue) for air conduction and "/1" (in blue) for bone conduction. These symbols are placed at the point on the audiogram where the verticle line designating the fre- quency crosses the horizontal line designating the intensity. Audiogram 1, page 80, illustrates the use of the above described symbols. When all thresholds have been found the audiologist can obtain a profile of the individual‘s hearing acuity by connecting each threshold with a line. Connell and Trow- bridge explain in general the interpretation of audiograms: No definite rule can be laid down for the inter- pretation of audiographs; however, as a working prin- ciple it can be stated that frequency losses not exceeding 30 db up to the frequency 1024, indicate damage to the conductive mechnaism, whereas losses above 1024 cycles and those exceeding 30 db below 1024 cycles indicate damage to the perceptive mechanism.5 PureeTone Audiometry as an Aid in Diagnosis Saltzman describes the general characteristics of an audiogram revealing the presence of stapes ankylosis: ¥ 5E. S. Connell and B. C. Trowbridge, "Essential Pro- cedure in the Diagnosis of the Abnormalities of Hearing with Some Audiometric Findings," The Laryngoscope, 52:548,July,1942. 79 Audiometry gives frequently a rather characteristic IDELttePn. . . . By air conduction the low tones are irlvariably affected and most often the hearing loss 113 uniform for all frequencies, but shallow v-curves said.dips at the higher side of the audiogram do occur. Ekone conduction, in gn uncomplicated case, is usually within normal range . Shambaugh explains the characteristics of an air con- dllcztxican audiogram indicating stapes ankylosis: The air conduction audiogram oftnueestapes ankylosis eeJChibits certain rather characteristic configurations. IIrl the early stages of beginning stapes fixation, the satiffness of the ossicular chain is increased resulting 111 a greater loss for low than for high frequencies. 'Ifiiis is termed the "stiffness tilt" in the audiogram fo‘partial stapes fixation. As the ankylosis becomes cuomplete, the stapes and labyrinthine capsule become (bile, and the mass of the capsule is added to the stiff- rress of the sound conducting system, with a hearing 1433s for the high frequencies, termed the "mass ffilattening" in the audiogram of complete stapes ankylosis. Uflne maximum hearing loss of pure stapes ankylosis (with- Crut complicating nerve degeneration) is around 60 Ciecibels for the speech frequencies.7 In regard to the characteristics of a bone conduction and iOgram, Shambaugh explains: The bone conduction audiogram of pure stapes ankylosis nlight be expected to give a "zero" threshold reading, trut Carhart has recently called attention to a charac- tkeristic notching of the bone conduction audiogram of C>tosclerosis, deepest at 2048, which largely disappears Elfter fenestration. Carhart suggests that this notch 3.8 a mechanical effect of stapes ankylosis, and that to Cietermine the true cochlear nerve response of a patient VVith otosclerosis the bone conduction audiogram should 1be corrected for this notch. The depth of the oto- EBclerotic notch probably varies, but it averages a loss (bf 5 decibels for 512, 10 decibelg for 1024, 15 decibels :for 2048 and 5 decibels for 4096. \ 6Saltzman, op. cit., p. 70. 7Wiener and others (eds.), op. cit., pp. 399-400. 8Ibid., p. 400. 80 Audiogram l, is an example of an audiogram indicating stapea-ES. ankylosis without cochlear degeneration in the right ear. The notch of Carhart is seen in the bone conduction curve - Saltzman states in regard to otosclerotic involvement of b0 th ears: Most often both ears are involved but not to the same degree. . . . In the case of otosclerosis, ES‘trapedial ankylosis is usually more marked in one €3>eagr than the other. Conversly, the ear with greater 1.1Trpairment for air-born sounds due to obstruction by exxdjxylosis should theoretically have better bone con- cirLlction than the other.9 '6 o E O 10 1o )2 15 15 20 20 30 so 35 35 .4o u 3 '5 50 so 0 D .E 60 60 3: “570 n 2 E. 80 ” Shaded Area N Is Beyond Mai-mum 9° Limits of Auduomefcr 100 . 100 Audiogram 1. Stapes ankylosis in the right ear. The Carhart notch is indicated in the bone conduction curve. (Note: Frequencies in cycles per second are represented in round number.) According to Saltzman the reason for their being be 1:t3631? bone conduction in the more seriously impaired ear is \ 9Sa1tzman, op. cit. 81 because of the fixation of the stapes footplate within the oval window. If this fixation is severe, the sound vibrations initiated through bone conduction are more effected within the bony labyrinth because their pressure is increased by the oval window closure. Only the unoccluded round window acts to reduce this pressure after the sound waves have innervated the nerve endings on the organ of Corti.10 Rure —'I‘one Audiometry as an Aid in Candidate Selection After it has been determined that stapes ankylosis is present within an individual, the otologist must then deGide whether or not the individual may benefit from the Stapes mobilization surgical procedure. In this respect, Nye PS and Ronis state: The best results are obtained in the ideal cases Of otosclerosis. Here, one should have the bone conduction above the 30 db level, preferably from 0—15 db, and a wide air-bone gap of 20-30 db.llThe air-conduction curve will vary from 30-50 db. The above mentioned criteria are also necessary for favoI‘able post-operative results from a successful fenes- tr.‘a~ti|.0n operation. However, Goodhill and Holcomb explain the differences in results that may be obtained from suc- ce SSfill fenestration operations and successful stapes mobili- Za ‘ ' tion operations. These author-s state: \ 10Ibid., p. 71. 11Myers and Ronis, op. cit., p.308. 82 The fenestration (detour) operation has a far more limited audiologic application in the treatment of otosclerosis than the stapedolysis (direct) approach. . A physiologic deficit must of necessity occur in fenestration surgery. . . . This means that post- operative air conduction will seldom be better than 15 db. below the preoperative bone-conduction response. Since an average of not worse than the 30 db. level in the speech frequencies is necessary for the restora- tion of practical physiological unaided hearing, it is necessary to start out with a good bone—conduction level, one not lower than 15 to 20 db. in the speech frequencies.l2 (As previously indicated in Section III, Chapter III, the speech frequencies are 512, 1024 and 2048.) Audiogram 2 illustrates the maximum amount of hearing loss by bone conduction that can be allowed in order that a successful fenestration operation can restore an individual's hearing to a level of practical hearing, according to the above quotation. ‘ BONE CONDUCTION . 250 500 1000 2000 4000 ‘ .1. -10 '5 0 ° e g 1. 10 l 15 15 l»’° ” 2 .5 ,0 3o 8 35 35 .5 40 40 l>~ 1% so 50 ‘5 E so 60 Audiogram 2. Degree of bone conduction loss allowed in order that the patient may receive favorable results from fenestration. In regard to stapes mobilization, Goodhill and Hal- comb explain: l2Victor Goodhill and Arthur L. Holcomb, "The Surgical Audiometric Nomograph in Stapedolysis," A.M.A. Archives pf Otolaryngology, 63:399, April, 1956. 83 There is no minimal physiological deficit in stape— dolysis (direct) surgery comparable to that in fenes- tration surgery . . . one can expect greater flexibility in the application of the stapedolysis (direct) approach . . a patient with a 20 db bone—conduction level and a 70 db. air-conduction level may still achieve a post- operative 30 db air conduction level. . .13 Audiogram 3 illustrates the maximum amount of hearing loss by bone conduction that can be allowed in order that a successful stapes mobilization operation can restore an (individual's hearing to the level of practical hearing, according to the above quotation. BON E CON DUCTION 250 500 1000 2000 4000 Normal I 8 388 853 o Intensity in Decibels 60 Audiogram 3. Degree of bone conduction loss allowed in order that the patient may receive favorable results from stapes mobilization. The physiologic deficit mentioned within the previous quotations concerns the absence of the normal air conductive route by way of the ossicular chain, after the fenestration operation. From the above information it appears that the pre- operative qualifications for post-operative adequate hearing 13Ibidu 84 are more flexible for stapes mobilization candidates than for fenestration candidates. This is true especially as, far as preoperative bone conduction.resu1ts are concerned. Providing there are no pathologic or surgical complications to interfere with the stapes mobilization surgical procedure, post-operative air conduction can equal preoperative bone conduction. Pathologic complications that could interfere with stapes mobilization surgical success are severe ankylosis that does not allow complete stapes mobilization and oto- sclerotic occulsion of the round window. Surgical complicationswill be discussed in Section VIII, Chapter V. Because it is not possible to predict the presence or occurrance of pathologic and surgical complications, accurate predictions as to the selection of ideal candidates and the amount of hearing that can be gained post-operatively can- not be made preoperatively. Problem of Bone Conduction Testing Suitability for the stapes mobilization surgical pro- cedure is greatly dependent upon the state of the cochlear nerve. The only present day methods of determining the state of the cochlear nerve, involve the employment of the various tests for bone conduction. However, many otologists feel that bone conduction tests are not totally reliable. Walsh and Silverman state: 85 Bone conduction tests are unreliable, we pay little attention to them except from the point of View of general screening of patients.1 These authors further explain that such tests of bone Q s U c1“Otion are primarily designed to determine cochlear ‘4. Q 4% tion, but that a loss of hearing by bone conduction fl 6%; ILot necessarily indicate cochlear damage.15 In this respect Walsh and Silverman explain: ‘Variables in the thickness of the cortex the pneu- InELtization and thickness of the tracebulae (partitions tmetween mastoid air cells) in the mastoid tegether vwith variations in thickness of the sub-cutaneous ‘tissues must influence the conduction of sound to the cochlga from a source placed on the bone behind the ear.1 Saltzman agrees with Walsh and Silverman. He feels that the degree and ease with which sound transmission through bone conduction will take place depends upon the characteristics of the respective tissues of the individual. He explains that the structure of the tracebulae within the mastoid bone is important for the proper transmission of sound waves to the labyrinth by bone conduction.l7 Saltzman refers to a study in which the mastoid bones were examined, post mortem, of individuals with known impaired ‘bone conduction, but whose hearing by air conduction was normal. The results revealed that all the trabeculae in the luWalsh and Silverman, op. cit., p. 544. 15Ibid. 16Ibid., p. 540. l7Saltzman, op. cit., p. 24. 86 SLlbadicus region were fractured. This author reports, "It appears that fractures of the trabeculae are common occur- I‘ehce S . ll8 $4 Although the reliability of bone conduction tests is QMlo nable, they are used extensively in testing for leear damage. The author found no evidence of other pre sent day methods used by otologists to determine the State of the cochlear nerve. II. TUNING FORK TESTS As an additional aid in the diagnosis of stapes ankylosis, tuning fork tests are employed by many otologists. Hirsh says, "Many clinicians still prefer the classical bone conduction tests with tuning forks."19 Farrior, Bagby, and Thomas state: In testing of bone conduction the tuning forks are, in the average quiet office, the most reliable method of testing the otosclerotic patient.20 The author could find no explanation presented by Brown and Farrior to support the above quotation. Hirsh believes, in reference to tuning fork tests: ' The otologist who has had experience with these tests, administered with a particular set of tuning forks, makes extremely accurate diagnostic judgments . . . designed to tell the clinician whether his 18Ibid. 19Ira J. Hirsh, The Measurement pf Hearin (New York: McGraw-Hill Book Company, Inc., 1952), p. 2 9. 2O Farrior, Bagby, and Thomas, op. cit., p. 2. 87 patient has a hearing loss of the conductive type or of the more central perceptive, or nerve type.2 Hirsh adds: In the hands of a precise, experienced clinician it appears that the tuning fork is a more useful diagnostic instrument than is the more precise pure- tone audiometer in the hands of an inexperienced, Oareless tester.22 Tuning forks are made of iron or an aluminium alloy, and. are designed to transmit the same frequencies as the Enlrwe-etone audiometer. One fork transmits one frequency. “Hue :fork:in structure, has a hilt or handle, and two tines. Wkanng fork tests are among the earliest methods used in bone conduction testing. Davis explains: The principles of high—tone deafness and of bone conduction were established by means of tuning forks, and the met od is still often used for rapid approxi- mate work. Generally, tuning fork tests are administered in the following manner. The fork is struck, which causes the tines to vibrate at the frequency the fork was designed to trans- mit. Davis states, "As the vibrations die down, the sound becomes fainter, and some idea of the patient's sensitivity can be obtained by noting how long he continues to hear the tone."24 However, all tuning fork tests results are not determined by how long the patient hears the tone. The Weber test is designed to determine where the tone is heard. 21Hirsh, op. cit., p. 282. 22Ibid., p. 283. 23Hallowell Davis (ed.), Hearing and Deafness (New York: Rinehart Books, Inc., 1953), p. 128. 24Ibid. 88' Davis feels that a serious limitation of tuning fork testing concerns the uncertainty as to the intensity of the sound produced. He further states, "This is true even when the blow used to start the fork is standardized as far as possible."25 Tuning fork tests that are used by many otologists as diagnostic aids in determining whether or not stapes ankylo- sis is present are the Rinne test, the Weber test, the Schwabach test and the Gelle test. Rinne Test According to Watson and Tolan the Rinne test has been used since 1885.26 Its results are obtained by comparing air conduction to bone conduction. Heller, Anderman, and Singer explain that this comparison concerns the duration of time the tuning fork is heard by air conduction and the duration of time it is heard by bone conduction.27 Watson and Tolan describe the administration of the Rinne test: The hilt of the vibrating tuning fork . . . is pressed against the mastoid bone behind the ear. When the subject indicates that it is no longer audible by bone conduction, it is instantly renoved and the vibrating tines of the fgrk are held directly in front of the open ear canal.2 251bid. 26Leland A. Watson and Thomas Tolan, Hearing Tests and Hearing Instruments (Baltimore: The Williams and Wilkins Company, 1949). p. 93. 27Morris F. Heller, Bernard M. Anderman and Ellis E. Singer (New York: Springer Publishing Co., 1955), p. 94. 28Watson and Tolan, loc. cit. 89 Interpretation ofRinne test results. According to ' is indicated when the Watson and Tolan, a "positive Rinne,‘ tuning fork is heard by air conduction after it is no longer heard by bone conduction. A "positive Rinne" is said to reveal a perceptive hearing loss.29 If the fork is no longer heard by air after it has ceased to be audible by bone, but is heard by bone con- duction after it is no longer heard by air conduction, Watson and Tolin, say that the test is a "negative Rinne." Such results would reveal a hearing loss attributed to defective air conduction.30 Saltzman states that, "Hearing by air conduction and bone conduction may be alike and the response is called Rinne neutral."31 As an aid in the diagnosis of stapes ankylosis, Saltz- man explains: Fork 512 d.v. is generally used for this test, but in otosclerosis also forks 1024 and 2048 are employed. If the Rinne is negative with all these forks, added confirmation of the diagnosis is obtained.32 Weber Test The Weber tuning fork test has been in use since 1834, according to Watson and Tolan.33 Hirsh explains that the 2 0 9Ibid. 3 Ibid. 31Saltzman, op. cit., p. 151. 2 3 Ibid. .33Watson and Tolan, op. cit., Do 95- 9O '" concerns the apparent localization of a Weber test, sound that is heard when the stem of a vibrating tuning fork is placed somewhere along the mid-line of the skull."34 Heller states that the Weber test is, ". . . employed to ascertain the lateralization of sound by bone conduction."35 Localization and lateralization are terms used in the field of audiology that concern the ear-that is stimulated by a transmitted sound. The element of time is not involved in determining tests results, as it is in the Rinne test. The localization of the transmitted sound:B of primary concern. Watson and Tolan state that usually the 512 cycle fork is used in the Weber test. To administer the test, the vibrating fork is placed in the center of the skull on the frontal bone.36 Interpretation of Weber test results. Hirsh offers the following judgments regarding Weber test results: . . . a person who has normal hearing in both ears usually localizes the sound either in the center of the head or "nowhere." . . . a patient with a unilateral (one ear) conductive loss will usually report the sound is heard on the side of the affected ear . . . a person with a unilateral perceptive type loss will repor§ that the sound appears on the side of the healthy ear. 7 34Hirsh, loc. cit. 35Heller, Anderman and Ellis, loc. cit. 36Watson and Tolan, op. cit. 37Hirsh, loc.cit. 91 Hirsh further explains: There are many variations of these judgments, de- pending on combinations of these different types of hearing loss and various amounts in the two ears.3 The author could find no information presented by Hirsh, or other authors, regarding the above mentioned judgment variations. Saltzman states that: For a reason not yet definitely determined, a vibrating tuning fork, the handle of which is placed on the vertex of the skull, will lateralize to the side of the ear having conductive deafness. Because stapes ankylosis produces a conductive hearing loss, it can be assumed in the diagnosis of otosclerosis in cases of unilateral losses, the ear that received the tone produced by the tuning fork during the administration of the Weber test is the affected one. The author found no information regarding Weber test results directly related to bilaterial (both ears) hearing losses, due to stapes ankylosis. However, the author assumes from the gathered infor- mation concerning the characteristics of bone conduction results in cases of stapes ankylosis, that in cases of bilateral deafness due to stapes ankylosis the tone may lateralize in the ear having the most severe ankylosis, providing both cochlear nerves are unimpaired. In cases 372239. 39Saltzman, op. cit., p. 148. 92 involving nerve impairment in both ears accompanied by stapes ankylosis, the tone may lateralize in the ear with the least amount of nerve impairment, providing neither stapes is com- pletely inhibited due to ankylosis. Schwabach Test Heller, Anderman and Ellis explain that the Schwabach test, compares the duration of bone conduction of the patient with the duration of the bone conduction of normal hearing.“lo Hirsh states: The schwabach test is essentially a crude test of absolute threshold by bone conduction. . . . Time, rather than intensity, is used as a dependent variable.l~ll The length of time is measured in seconds by a stop- watch. According to Hirsh the person administering the Schwabach test tries to strike the tuning fork in such a way that the initial amplitude is always the same. This author explains, " since the decay of the fork may be assumed to exhibit the same characteristics on successive trials the clinician may use time as a measure."42 The duration that is measured is the time taken for the fork to decay from its initial amplitude to whatever amplitude corresponds to the patient's threshold. uoHeller, Anderman, and Ellis, loc. cit. ulHirsh, op. cit., p. 283. 4 2I'bi'd' . * 93 Interpretation of Schwabach test results. Watson and Tolan describe the interpretation of Schwabach test results in the following manner: The bone conduction is said to be increased, normal, or decreased depending upon whether or not he hears the tuning fork by bone conduction longer, the same or for a shorter time than the normal hearing person. 43 Hirsh says, ". . . Schwabach tests performed on oto- sclerotics in sound treated rooms seem to indicate that in some cases at least, bone conduction is better than normal."44 Therefore, in uncomplicated cases of otosclerosis, stapes I ankylosis may be present in the ear perceiving the tuning fork longer than normal during the administration of the Schwabach test. Gelle Test Heller, Anderman and Ellis state that the Gelle test, ". . . was conceived in an effort to determine the mobility of the stapes."45 . According to Bunch the Gelle test,'". . . is based on the fact that the acuity of hearing in a normal ear varies with the increase and decrease of pressure in the external auditory canal."46 Air pressure is introduced into the external ear canal during the administration of the Gelle 43Watson and Tolan, loc. cit. uuHirsh, op. cit.,p.l49. 45Heller, Anderman and Ellis, loc. cit. “6C. C. Bunch, Clinical Audiometry (St. Louis: The C. V. Mosby Company, 1943), p. 25. 94 test - Bunch describes the administration of the Gelle test: An olive tip . . . and a valveless Politzer bag are attached to the opposite ends of a rubber diagnostic tube . Insert the olive tip in the external auditory me atus and compress the Politzer bag to see that no air escapes. Press the handle of the vibrating fork against the patient‘s head. As soon as he hears the sound of the fork, increase the air pressure in the exteinal canal by gently compressing the Politzer bag - 7 Intemretation of Gelle test results. Bunch states that if the listener hears the tone more faintly when the pres sum is applied to the air in the canal, stapes ankylosis is “Qt present. Stapes ankylosis may be present if there is no Change in the intensity of the sound.u8 III. SPEECH AUDIOMETRY In regard to the selection of prospective candidates for the fenestration operation, Rosen says: Pure-tone and speech audiometry tests have increased knowledge and predictability as to the results tobrpe eJ‘ipected following fenestration for otosclerosis. Because the criteria for candidate selection for f eneE"JCI‘ation is similar to that for stapes mobilization, the a uthor‘ assumes that Rosen‘s above statement might apply to St ape S mobilization. Speech audiometry differs from pure-tone audiometry in . that the threshold does not concern just the listener‘s \\ 47Ibid. “81bid. D. 610 249Rosen, "Palpation of Stapes for Fixation," op. cit., 95 ability to hear sounds, but his ability to identify words, either in isolation or in context with other words. Saltz- man explains in regard to speech audiometry: . . . The information to be derived from the pro- cedure concerns the patient's ability to understand speech as it is delivered by his fellowman under the ordinary circumstances of life.50 Davis reports: In a speech audiometer we use as our source of power an electrical current that varies according to the pattern of the human voice. The current is generated either by speaking into a microphone pf by electrical pick-up from a phonograph record. Speech audiometry tests that are used in the diag- nosis of stapes ankylosis, and the selection of prospective stapes mobilization candidates are the speech reception threshold test and the speech discrimination test. Heller, Anderman and Ellis state, "Discrimination testing generally follows the determination of the speech reception threshold for spondaic words."52 Speech Reception Threshold Test Carter says in reference to speech reception threshold testing, "Speech reception does not reveal the pattern of hearing loss. It gives a composite threshold."53 The deter- mination of this threshold is similar to the determination 50Saltzman, op. cit., p. 144. 51David (ed), op. cit., p. 137. 52Heller, Anderman and Ellis, op. cit., p. 120. 53Howard Carter, "Review of Methods Used for Estimating Permartage of Loss of Hearing," The Laryngoscope, 52:880, N0v.,.l9 2. 96 of a pure-tone threshold. Heller, Anderman, and Ellis explain: The pure tone audiometer uses average normal hearing as the reference level. The ratio, in decibels, between the measured threshold and the normal or zero line, is taken to be the hearing loss at a given frequency. A similar concept obtains with regard to speech reception threshold. If selected material is heard by the normal ear at zero decibels, and by a defective ear at 40 decibels, then the defgfitive ear has a 40 decibel loss of hearing for speech. According to Heller, Anderman and Ellis the material used in obtaining an individual's speech reception threshold should concern words that are alike in their difficulty of audibility. These authors further state: In selecting words . . . it was considered important that they be familiar in the language, in order to minimize the importance of the factors of intelligence and knowledge of vocabulary.55 Watson and Tolan are of the opinion that: Spondee words as in Harvard test No. 9 are the most useful material for speech reception threshold tesgs, whether recorded at constant level or attenuated.5 Egan describes Spondaic words: . . . class of words having the highest homogeneity . dissyllables spoken with equal stress on both syllables. . . . Examples are railroad, iceburg, horse- shoe. 54Heller, Anderman and Ellis, op. cit., pp. 119-120. 55Ibid., p. 120. 56Watson and Tolan, op. cit., p. 147. 57James P. Egan, "Articulation Testing Methods," The Iaryggoscope, 58:965, September, 1948. 97 Spondaic words are delivered from a previously recorded phonograph record, or by live voice. Hirsh explains: The procedure for measuring the Hearing Loss for Speech may employ as a source of speech, either the live voice of the tester or speech that has been recorded on a. phonograph disc or magnetic tape. If live voice is used, precautions must be taken to provide the speaker with a visual indication of the intensity of his voice so that he may, with practice, monitor his voice and so keep his intensity constant. The control of the intensity of speech arriving at the listener's ear should be accomplished with attenuators in the equip- ment , ngt by varying the intensity of the speaker's voice.5 Other material is used, besides Spondiac word lists, to measure an individual's speech reception threshold. However, the author feels that a discussion of these other matel‘ials is beyond the scope of this study. fine administration of speech reception threshold test. Watson and Tolan explain that in live voice delivery the examiner administers, '". . . speech reception threshold tests either. through microphone speech circuit of an audiometer or through special free field reproducing equipment- ~‘"59 In free field testing the individual being tested dOes not wear earphones. In a microphone speech circuit testing situation, earphones are worn. When earphones are worn the examiner can test either by air or bone conduction. If unilateral testing is desired the individual is ins thug ted to turn the ear not being tested away from the —\ 58Hirsh, op. cit., p. 90. 59Watson and Tolan, op. cit., p. 449. 98 loudspeaker and to occlude it with his forefinger, in the free field situation. In unilateral testing where earphones are worm, the examiner can inhibit the transmission of sound into the ear not being tested by the use of masking. Masking involves the transmission of noise into the ear not being tested. Masking can also be used with free field testing. The method of test procedure involves the transmission of the Spondee word to the individual being tested and his I‘fii‘peath'ig the word as he hears it. Generally, a carrier phrase such as, '"Say the word," precedes the Spondee word. The intensity of the Spondee transmission usually begins at about 40 db depending upon previous knowledge of the eXaJninee's hearing acuity. The intensity is decreased as the test progresses. Heller, Anderman and Ellis describe one me thod of determining the intensity with which to begin the test, They state in regard to previous information learned from the individual's pure-tone audiogram, "- average the two speech frequencies showing the smallest losses - The spondiac words are then presented at a level abOUt 15 decibels above this estimate.”60 These authors further state, "Threshold is taken to be the lowest level at which fifty per cent of the words are correctly repeated by the patient.“" 61 \ 60Heller, Anderman and Ellis, op. cit., p. 127. 61Ibid. 99 Interpretation of speech reception results. Speech reception results are helpful in determining whether or not the cochlear nerve is affected. Davis states: If words are delivered to the ear, either through a. receiver or in a free field, at 50 db above normal threshold they begin to be heard by bone conduction.62 Therefore, from Davis' above observation it might be assumed that a speech reception loss 50 db above normal threshold, may indicate injury to the cochlear nerve. In this re spect he further states: 50 db loss represents probably the greatest loss fOr speech that can be caused by pure conductive Cieezamfness. . . . If tests show a loss for speech greater than 50 db it is usually safe to conclude that there is a loss of sensitivity of the sense Organ (nerve deafness) as well as conductive deafness.63 As a diagnostic aid a speech reception threshold test might prove of value in determining whether or not a conduc- tive loss due to stapes ankylosis is further complicated by a pepcZeptive loss. §Le—-e&_Dis criminat ion Te s t It was previously stated that the speech discrim- ination test generally follows the speech reception thres- h Old 1Zest. Heller, Anderman and Ellis state: Once threshold has been determined, valuable diag- 1gostic information can then be obtained by speech eLets at levels above threshold. Measurements at \ 62Hallowell Davis, "The Articulation Area and the Adequacy Index for Hearing," The Laryngoscope, 58:766, , 1948. 63Ibid., pp. 766—767. 3001 8. Angus PE 100 these supra-liminal levels are designed to explore how a defective ear operates when its hearing loss for speech is overriden by %£esenting material at a sufficiently intense level. Hirst states that speech discrimination tests are important to the clinical situation for this measure pro- viding additional information that cannot be predicted from threshold measurements. This author explains: It is well to say that a person has a 30 db hearing 1.08 s for spondees, but we do not know from this infor— mat ion alone how much speech would be intelligible if the intensity were made sufficiently great. . . . Ideally the ciling that could be reached by increasing the intensity of speech is 100 per cent, but some persons can never get more than 40 or 50 per cent no mat ter how intense the speech. In speech discrimination testing it is generally conside bed that the use of PB words produces the most I“~‘311able and valid results. Heller, Anderman and Ellis describe PB word lists in the following manner: They consist of familiar words of one syllable arranged in groupings of fifty words to a list. The 1r112eention is that each list be of comparable difficulty and of equal phonetic structure. . . the lists contain the elements of sounds spoken in gas frequency of the ir occurrence in the language. According to these authors, the PB words should be d eliveI‘ed at least 40 decibels above the speech reception th - I‘esho 1d to obtain the maximum PB score. If there is no \ 64Heller, Anderman and Ellis, op. cit., p. 121. 65 r-' Hirsh, op. cit., p. lu(. 66Heller, Anderman and Ellis, op. cit., p. 122. .00! . c-va lOl tolerance problem (inability to tolerate certain intensi- ties) the test may be administered at a greater intensity.67 Speech discrimination test "score" and'"loss." According to Heller, Anderman and Ellis, the determination of speech discrimination "score" involves the number of words heard correctly by the examinee. The speech discrim- ination "loss" is the percentage of PB words not correctly heard. For example, "If ten words are missed then the dis- crimination loss is 20%."68 Interpretation of speech discrimination results. Saltzman states that in speech discrimination testing,'"With proper amplification, the word hearing of an otosclerotic is frequently 100 per cent correct. . ."69 However, such word intelligibility is only attainable if a nerve impairment does not accompany stapes ankylosis. In regard to sensory impair- " in nerve deafness this score is "70 ment Saltzman adds, hardly attained by amplification. Therefore, from Saltzman's observations it can be assumed in the diagnosis of otosclerotic severity, that a high speech discrimination loss using PB words might indicate 67Ibid., p. 128. 68Ibid., p. 74. 69Saltzman, op. cit., p. 70. 70Ibid. 102 cmchlear damage. For the most favorable results that can In obtained from stapes mobilization, a prospective candi- date should have a speech discrimination score close to 100 per cent correct. IV. VALUE OF AUDIOMETRIC TESTING The above discussed audiometric testing battery is a valuable aid in diagnosing stapes ankylosis and selecting prospective candidates for the stapes mobilization surgical procedure. However, such a battery is only an aid to the otologist and decisions as to diagnosis and candidate selection should not be based upon the results of the audio- metric testing battery alone. It is important that audiometric testing be accom- panied by a thorough otologic examination in order that other middle ear complications that might produce similar audiometric results, as those produced by stapes ankylosis, may be ruled out. CHAPTER V STAPES MOBILIZATION The stapes mobilization surgical procedure, if suc- cessful, provides a normal conductive route for air-borne SOunds to the fluids of the inner ear. Rosen and Bergman State : Recognizing the obvious advantages of utilizing r'IESLtUJ'e's own pathway of sound conduction via the intact and freely moving ossicular chain, one of us (3 - R.) developed the employed a technique . . for the deliberate mobilization of the fixed footplate of the stapes.1 As it was previously mentioned in this study, Rosen PeViVed stapes mobilization in 1952 after it had been abandOned as a cure for otosclerotic deafness due to stapes ankle Sis in the early nineteen-hundreds. Since its revival Stape 8 mobilization has been employed by otologists through- out the world and many have added their own techniques to the 8 L1 rgical procedure . The author feels that in order that the purpose of thi s S‘tudy can be adequately fulfilled, each major phase of the stapes mobilization procedure should be considered. D1 agno sis and selection of prospective candidates, operation \ Qto 1Rosen and Bergman, "Mobilization of the Stapes for SC31erotic Deafness," op. cit., p. 177. ION g3aJ.su, surgical techniques, pre-operative and post—operative treatment, surgical audiometry, operation complications and success and failure determinants will be discussed within this chapter. All of the information that will be included within this; crkiapter has been gathered from published materials, Witkl Tifde exception of that concerning the experiences of Dr. liailrold Schuknecht. The author had the opportunity and privi:Leege to observe three of Dr. Schuknecht's stapes mobili- zation operations at Henry Ford Hospital in Detroit, Michigan. I. DIAGNOSIS AND CANDIDATE SELECTION Audiometric test results aid the otologist in diag- nosing stapes ankylosis. However, such results are limited in tha t they only reveal whether a conductive or perceptive hearing loss is present, whether a mixed hearing loss is present and the severity of a hearing loss. The cause of a hearing impairment cannot definitely be determined through audiometric testing. Therefore, in the diagnosis of stapes ankylosis other factors must be consj-Ciered. WFactors to be Considered in Diagnosis According to Shambaugh: Otosclerosis does not produce any absolutely diag- 1'1<>stic symptom or sign. The history, however, is of Clonsiderable help in suggesting that a conductive 105 type of hearing loss is of otosclerotic origin, and by excluding the other five causes of conduction deafness the definite diagnosis gf primary otosclero- tic stapes ankylosis is reached. Shambaugh further adds, "The only constant and the IHOSt characteristic symptom of otosclerosis is the slowly t 3 Progressive hearing impair-men Saltzman agrees with Shambaugh on this point and sayS, "Of utmost significance is a.hisstnary of progressiveness of the deafness in the absence Cfi’ari (otologic condition to account for it."u In discussing the rate of the hearing impairment's PPOEPe ss, Shambaugh explains: 'The rate of progress of the hearing loss is typically slow and gradual, but with definite dif- 17€Elrences between individuals and at different times erl the same individual. The progress may be con- tZfiLITuous or it may halt and the hearing remain $31:zabilized fog a period of years before it begins to 'VVCDIrsen again. Walsh lists the following four points to be consid- flfid- Zign addition to audiometric test results, upon which t ObEa-53era.diagnosis of stapes ankylosis: (l) a progressive loss of hearing, particularly leTL a young person; (2) a history of deafness in .tVFIe family; (3) no previous infections of the ear ‘:lfilat might accoung for the hearing loss; and (A) 'Cbrmal ear drums. ..~““‘~“ 2Wiener and others (eds.), op. cit., p. 396. 3Ibid. 4Saltzman, op. cit., pp. 72-73. 5Wiener and others (eds.), op. cit., p. 397. 6Davis (ed.), Hearing and Deafness, op. cit., p. 107. ||.|\f3.lll|rb 106 A pure-tone air conduction audiogram revealing the pmfiern previously described in Section I, Chapter IV, by SEUZman as being indicative of stapes ankylosis, may be Um result of other middle ear complications. Shambaugh dbscribes five other causes of conductive deafness, and expleiins how these causes can be ruled out in stapes ankylo sis diagnosis: 1. Occlusion of the external auditory meatus (czeerumen, osteoma, atresia, etc.) is easily ruled c>Litr by otoscopy. 2. Perforation of the tympanic membrane is ruled CIth: by otoscopy, with the Siegel-Bruning speculum Eirlci. inflation of the eustachian tube, if in doubt. rative otitis media (infection of the acute or chronic, is easily diagnosed 3. Sup u rnicidle ears) by otoscopy. A. Occlusion of the eustachian tube with secre- t3"¢>:I:‘~yotitis media gives a greater loss for high tones 'tikléan for low tones in the audiogram. The yellowish :i‘Z'JLor of the serum filling the middle ear may be vaaheen through a transparent tympanic membrane, often ffilth a fluid level or bubbles, especially after in- 1_1:LEsition, and by inflation there is a measureable EEEEaring improvement. Evacuation of the fluid by DELracentesis and inflation results in a restoration (35:? the hearing to normal. 5. Chronic adhesive otitis media is the end he sult of a previous severe suppurative otitis media, (1 the hearing loss very definitely dates from the (151.5charging ear. Nearly always there are marked alter- ions in the tympanic membrane as part of the adhesive 1Focess, and the hearing loss, once established soon f‘ter the suppurative process, is not progressive.7 According to Shambaugh, although hearing tests of St 31398 ankylosis are generally characteristic, and are very \ 7Wiener and others (eds.), op. cit., p. 405. 107 vaJJaertflle aids in diagnosis, ". the definite clinical diagnosis cannot be made until the other five causes for conduction deafness have been ruled out by otoscopy and 8 examination of the eustachian tubes. . ." Another element that is believed to be characteristic of otosclerotic deafness due to stapes ankylosis is “para- cusis willisi.‘" Walsh explains: The patient with otosclerosis . . . seems to hear better in a noisy place, for example, on a streetcar, 31f). an automobile, or in a factory.9 Saltzman described "paracusis willisi," as, ". the allbgility to hear better in the presence of loud surrounding noise; ‘than in a quiet room."10 Walsh is of the opinion that .11 iPaPELc21Jsis willisi," is due to the fact, ". that people Witkl rixormal hearing naturally raise their voices to over- come the surrounding noise {"11 "Tinnitus" is another factor that may be present in O"503C22Lerosis. This phenomenon is characterized by the pI‘eSel’lce of head noises. Sis, Saltzman states that in otosclero- “It is usually of the nature of a low rumbling noise but 1_t: may be high-pitched."l2 Shambaugh explains: The tinnitus of otosclerosis is an irregular E3Bnmptom, often severe, but it may be absent, or it \ 8Ibid. 9Davis (ed.), loc. cit. lOSaltzman, op. cit., p. 37. llDavid (ed.), loc. cit. l2Saltzman, op. cit., p. 73. 108 may disappear spontaneously, with no consistent relation to the hearing impairment, except that the most severe cases of tinnitus tend to be in patients with severe cochlear nerve degeneration complicating the conductive loss. We do not know th exact mech- anism of tinnitus in otosclerosis. In regard to the voice characteristics of a person dffected by stapes ankylosis Shamburgh states: First, there is a tendency for the patient to speak too softly, especially in noise, partly because Iaj;s.own voice sounds louder than normal to him, and gastrily because he is not aware of the noise. Later, ‘tldee voice tends to acquire a "hollow" quality, and .ffiizually, if marked cochlear nerve degeneration com- plicates the picture of pure stapes ankylosis, the voice tends to acquire some of the toneless quality of profoundnerve deafness.14 'Therefore, in addition to audiometric test results, alloif‘ 'the above mentioned factors must be considered in We 613451gnosis of stapes ankylosis. EEEEEiELEiis of Uncomplicated Cases of Stapes Ankylosis An uncomplicated case of stapes ankylosis would be (me 1:hlast is free from cochlear nerve impairment. Providing th . at ‘Eilfi examination by the otologist rules out the five oflmnr‘ Iniddle ear complications, and the patient shows a histgby of a slowly progressive hearing impairment, the £0110‘leng audiometric test results strongly suggest the preESEEIIAce of uncomplicated stapes ankylosis: l. A pure-tone audiometric test by air conduction is su ggestive of the presence of uncomplicated stapes ankylosis \ 13Wiener and others (eds.), op. cit., p. 397. l“Ibid., p. 398. 109 if‘ the results reveal that the low tones are affected and show a uniform hearing loss for all frequencies, or shallow v-CuI‘VeS and dips at higher frequencies. According to Shambaugh, "The maximum hearing loss of pure stapes ankylo- sis (without complicating nerve degeneration) is around 60 decibels for the speech frequencies (512, 1024 and 2048);"15 2. A pure-tone audiometric test by bone conduction is suggestive of the presence of uncomplicated stapes ankylosis if the results show that hearing for all frequen- cies, with the exception of 2048, is within the normal range of hearing. A loss at the 2048 frequency level, which is characteristic in otosclerosis according to Carhart, was explained in Section I, Chapter IV. 3 - A 3192?. tuning fork test is suggestive of stapes ankylosis free from nerve impairment if it produces “negative" results. "Negative" results are produced when the fork Vibrations are no longer heard by air conduction after they have ceased to be audible by bone, but are heard by bone conduction after they are no longer heard by air. U“ A E3923 tuning fork test is suggestive of uncom- plicated Stapes ankylosis if in unilateral deafness the tone lateralizes to the affected ear. In bilateral deafness the tone may lateralize to the worse ear. 5- A Schwabach tuning fork test is suggestive of this condition if the tone is perceived by bone conduction lon e ' g P than it is heard by a normal hearing person. \‘\\— l 532151., p. uoo. 110 6, A gill? tuning fork test is suggestive of stapes ankylosis free from nerve impairment if there is no change in the intensity of the sound after air pressure has been introduced into the external ear canal. 7. A speech reception threshold test is suggestive of this condition if the results show a threshold from 50 db to 60 db. 8. A speech discrimination threshold test is sug- gestive of stapes ankylosis free from nerve impairment if the results reveal a low "loss" and a consequent high '"score" close to 100 per cent correct. Diagnosis of Complicated Cases of Stapes Ankylosis It is difficult to determine through the use of tuning forks whether or not a nerve impairment accompanies Stapes ankylosis. Therefore, only the results that indicate complicated cases of stapes ankylosis obtained from pure-tone and Speech audiometry will be reviewed as follows: 1- A pure-tone audiometric test by air conduction is suggestive of a complicated case of stapes ankylosis if there is an extensive loss for all frequencies, or losses in the high frequencies. 2‘ A pure-tone audiometric test by bone conduction is suggestiVe of this condition if it shows a threshold r g eater thalq 20 db for some, or all frequencies. 3' A speech reception threshold test is suggestive of Stapes ankylosis accompanied by a nerve impairment if it . v-. --—J'.‘ Q V 111 .S’ éOWS a hearing loss greater than 60 db. 4. A speech discrimination test is suggestive of an accompanying nerve impairment if the results reveal a high .nlosS" and a consequent low "score." Diagnostic Summary In summarizing the diagnosis of stapes ankylosis, Sharnbaugh states: The history of a slowly progressive hearing im- pairment beginning insidiously in early adult life, with the tuning fork and audiometric tests of a con- ductive hearing loss, strongly suggests the diagnosis of otosclerotic stapes fixation. When the other five causes for a conductive loss have been ruled out, definite clinical diagnosis of otosclerosis may be the ruede.l In addition, a soft speaking voice, the presence of "‘paracusis willisi," and "tinnitus" all may be symptoms indicating a hearing loss due to stapes ankylosis. Selec tion of Prospective Candidates According to House any patient who is suitable for the fenestration operation is also suitable for the stapes m0bili zation surgical procedure. This author adds further: Many patients are suitable for mobilization who W0 uld not be eligible for fenestration surgery. . . and patients with EXaanles include the aged . PaL‘tlher far advanced cochlear deterioration. \ l6Wiener and others (eds.), op. cit., p. 407. Nobil l7Howard P. House, “Personal Experiences with Stapes Map ization,“ A.M.A. Archives of Otolargggology, 65:243, ch: 1957. ‘— __ ,_ #7 3.. 112 From the gathered information presented in Section I, ChapteIT IV, the author assumes that if an individual with a hearing; loss due to stapes ankylosis, has not more than a 30 db ‘threshold by bone conduction, he is a favorable candi- date f<3r stapes mobilization. The ideal candidate is an indiviciual whose pure-tone bone conduction results reveal, not more than a 20 db threshold. This would indicate normal hearing by bone conduction. Stapes mobilization is also beneficial to individuals with severe hearing losses. Although, it. cannot restore normal or near normal hearing in such cases, it can improve hearing so that aural rehabilitation will be more effective. However, it is necessary that there be a sufficient air- bone gap in order that a patient may benefit from this Operation. In this respect House explains: Any patient with an average difference of 20 db OI‘ more between the bone conduction and air conduction in any three frequencies may be considered suitable f‘01" mobglization, regardless of the bone conduction level.)- In regard to the severity of preoperative air—bone difference Schuknecht is of the opinion that a maximum of 30 db difference indicates an ideal candidate for stapes mObilization. A 40 db difference indicates a moderate case 01" Stapes ankylosis and a 40 db to 60 db difference indicates seve re ankylosis . 19 \— 18Ibid. 1 9EStatement by Dr. Harold F. Schuknecht, Associate Su beggilg’ Division of Otolaryngology, Henry Ford Hospital, ’ 1VIichigan, Personal communication, July 18, 1957. 113 II. OBJECTIVES OF STAPES MOBILIZATION - The primary objective of the stapes mobilization surgical procedure is to restore as much of an affected individual's hearing as is physiologically and surgically possible. The degree of hearing improvement that can be obtained through surgery is dependent upon the characteris- tics of the prospective candidates hearing involvement and the success of the surgical procedure itself. Bergman states : Surgery, such as stapes mobilization, can provide a patient with normal hearing or with hearing which garb: utiiigicliirgorioifgsctively in a program of g re a a . In considering the various objectives of stapes mobilization within this section of the study, such ob- Jectives will be divided into the following three groups; that which concerns uncomplicated cases of stapes ankylosis; those which concern complicated cases of stapes ankylosis; and that which concerns the physiological aspects of the Operation . 91laECLZI-Ve in Uncomplicated Cases In operations involving patients with hearing losses due to Stapes ankylosis free from nerve impairment there \ 20 . Bergman, op. cit., p. 285. 11H is but one objective. Rosen and Bergman explain that this goal is , '"To attain normal hearing."21 These authors further add: Mobilization of the fixed stapes is capable of acklieving this goal where there is gs yet no coczhlear (perceptive) involvement.2 Providing there are no complicating factors within the surgical procedure and the round window is unoccluded, normal hearing can be attained in cases of bilateral or unilateral hearing impairment free from nerve damage. ObJectives in Complicated Cases Rosen and Berman list the following goals to be obtained through stapes mobilization in complicated cases 0f Stapes ankylosis: To restore hearing to an 11 db to 20 db level in patients with some evidence of perceptive loss in Whom normal hearing is not possible. . . . To restore useful binaural hearing. . . . To permit guccessful use of hearing aid in extreme deafness.2 In regard to the first objective these authors explain that a person, ". . . with a hearing loss between 11 db and 20 db rarely experiences any hearing difficulties." There- fore, in cases where the pre-operative pure-tone audiometric test reveals a 20 db threshold for bone conduction, and a greater loss for air conduction, it is still possible to \ MObil ElSamuel Rosen and Moe Bergman, “Functional Goals in , iZation of the Stapes," A.M.A. Archives of Otolaryngology, 6 3'11, J‘a_r1uary, 1956. e Enid” p. 19. 23Ibid., p. 12. 115 restorwe useful, unaided hearing through successful stapes mobili zation surgery . The restoration of useful binaural hearing in cases of unilateral or bilateral deafness is advantageous. Berg- man states that binaural hearing has the following advan— tages over monaural hearing: (1) localization, the ability to determine the directional source and distance of a sound; (2) selectivity, the ability to listen to a conversant's speech with little or no interference from competing noises in the area (this is implied when a patient with one normal and one defective ear reports a distressing deterioration in his abilit to under- stand speech in a noisy enviornment); {3) discrim- ination, the ability to hear speech sounds and to discriminate them more clearly both in quiet and over a background of noise; (45 sound identification, the abiifity to identify common sounds and noises better. . Therefore, the author assumes that Rosen and Bergman advocate an attempt to restore or improve hearing in all affected ears in order that binaural hearing can be achieved, if phys iologically and surgically possible. In regard to the third objective of stapes mobiliza— tion, " To permit successful use of hearing aid in extreme deafness," Rosen and Bergman state: The gain or amplification of the strongest com- merc ial hearing aid is insufficient to provide com- f0Ptable hearing for ordinary conversation in a Patient with a hearing loss in the better ear greater than 85 db. Any significant improvement in hearing in Such profound deafness increases greatly $518 benefits to be derived from the use of a hearing aid. \— 2‘Z‘LIBergman, op. cit., p. 282. 2’Sifiosen and Bergman, "Functional Goals in Mobili- Zat ion of the Stapes," op. cit., p. 16. | . '1’ 21¢] 1‘1’ 116 In cases of complicated stapes ankylosis it is possibile, through stapes mobilization, to eliminate the portioxfi of deafness due to the immobility of the stapes and leave jpure nerve deafness. Depending upon the severity of thiSjp1dre nerve deafness, an individual may receive more benefiqt from a hearing aid than he would have received had the opueration not taken place. Such benefits may be con- sidereci in light of the ability to understand normal con- versat ion, or the ability to operate more effectively in a Program of auditory rehabilitation. PiniOlogical Objective of Stapes Mobilization. Goodhill explains that the physiological objective in Stapes mobilization is, '". . . lysis (breaking down) of obstmc tion in the stapediovestibular junction so that remobilization of the footplate to air-borne sound may Occur." 26 Goodhill adds further: The ultimate physiological objective in stapedolysis depends upon two factors: a. satisfactory lysis of the footplate obstruction, and b. maintenance of the functioning middle ear mechanism. The degree to which the stapes can be mobilized is greatly dependent upon the extent of otosclerotic bone growth at the margin of the footplate. The more severe the \ p. 334 26Goodhill, "‘Present Status of Stapedolysis," op. cit., 2377 ZEbid., p. 336. N—I— 117 extent of ankylosis, the more problems the surgeon will encoun ‘ter in his attempts at mobilization. During mobilization it is possible for the surgeon to ace idently disarticulate the head of the stapes from the lenticular process of the incus. Surgeons have also reported incidents in which either of the two crura of the stapes have been fractured during mobilization. If any one of these two accidents occur a dysfunction of the middle ear apperatus will take place. It appears to be unknown if the occurrence of these two accidents is common. Sitapes Mobilization Possibilities. Generally speaking, the amount of hearing that can be gained following a stapes mobilization operation is limited by the state of the cochlear nerve. Goodhill €Xpla1n S: Upon achievement of maximum lysis surgically it is possible to expect an almost. complete eradication Of the conductive block and an elimination of the air~bone gap, so that hearing post-operatively approaches the preoperative bone conduction level. In some cases this level will even bg surpassed due to improved perilymph mobility.2 The possibilities of the stapes mobilization operation for the restoration of hearing in cases of stapes ankylosis appear. to be very favorable. However, the possibilities Should be evaluated in light of the characteristics of the \— 28Ibid., p. 331+. 118 hearing, disorder involved; the extent of otosclerotic bone growth; and the effectiveness of the mobilization techniques employed by the surgeon performing the operation. III. PREOPERATIVE CARE The author found little information concerning the amount of time the patient is required to spend in the hospital preoperatively when involved in the stapes mobili- zation surgical procedure. However, in this respect, Shambaugh tells a stapes mobilization candidate: The advantages of stapes mobilization. . are first of all, its simplicity as far as he is con- cerned, with only three days away from work as compared to three weeks with fenestration in the ave rage case . Pflyers and Ronis explain, "Our patients are hospital- ized for 24 hours. The patients are admitted on the morning 0f the operation .'" 3O Schuknecht requires that his patients enter the hoSpital the day before the scheduled operation is to take place. During the time spent in the hospital preoperatively, the patient is given proper rest, diet and is prepared for x 29Symposium, op. cit., p. 715. 3C)Myers and Ronis, op. cit., p. 309. 31Statement by Dr. Harold F. Schuknecht, Associate Su Def-13:13, Division of Otolaryngology, Henry Ford Hospital, : Michigan, personal interview, April 27, 1957. 119 Factors concerned in preparation for surgery will be consiCiered within this section of the study. Such factors invol‘Je preoperative medication and the preoperative physical preparation of the patient. Preoperat ive Medic ation As previously mentioned, many otologists have devel- oped their own individual techniques for the administration of the various phases of the stapes mobilization surgical procedure. In regard to the preoperative medication phase of Stapes mobilization, the author learned that medication is ad- ministered priorto andafter hospital entry. However, some otologists only administer medication after hospital entry. Preoperative medication prior to hospital entry. The Primary purpose for the administration of medication prior to hospital entry is to prevent post-operative middle ear infection. Myerson explains, "In order to prevent middle ear infection after operation strict asepsis (free from living germs of disease) is important."32 So that proper precautions can be taken to prevent the Possible occurrence of post-operative middle ear infection, MyeI‘SOn feels that attention should be paid to the nose, \— 0t 32Mervin C. Myerson, "Mobilization of the Stapes for Ju§>801epo sis," A.M.A. Archives 93 Otolaryngology, 64:85: y‘December, I956- will“. I in... 120 nasopharynx and external auditory canal before entry into the hospital.33 Myerson states, "The operation should not be performed in the presence of sinus suppuration or active nasal or nasopharynx infection."34 As preventive measures against such infections, Myerson explains: . . . the nasal passages are irrigated daily, for three days, before operation with warm saline solution. $23,230{it"fiifir‘éi’hiflifiit{finiithi‘éfléntiifiém °f Myerson further adds: The patient is instructed to introduce 3 minims (0.2 cc.) of a 0.125% phenolized oil into each nasal chamber three times a day for one week before surgery. 36 In regard to preventive measures against possible infections occurring in the area of the external ear canal, Myerson explains: he is instructed to introduce a dropperful of aqueous solution of benzalkonium, 1:1000, into the external ear canal three times a day for three days before the operation.37 From the information reviewed by the author, it seems apparent that such preoperative medication precautions are not commonly practiced by all otologists. Preoperative medication employed after hospital entry. The objective of this phase of preoperative medication is 33Ibid. 34Ibid. 35Ibid. 36Ibid. 37Ibid. 121 to produce a calming effect in the patient before entry into the operating room. Goodhill says: The preoperative medication for stapedolysis surgery should not be heavy. It should be sufficient to produce a calm entry into the operating room, but not deep enough to obtund aggurate responses for aduiometric threshold studies. In order that the above requirements be met, Goodhill explains: Three grains of sodium pentobarbital are sufficient for this procedure; this medication is given in divided doses about two hours and one hour before surgery.39 Rosen and Bergman state in regard to this phase of preoperative medication, "The patient is given pentobarbital (Nembutal) 1-1/2 grains (90 mg) an hour before the opera- MO tion." According to Scheer's technique, "Premedication consists of pentobarbital (Nembutal) (1-1/2 grains (0.10 gm.)) and meperidine (Demerol) hydrochloride (50 mg.)."ul Although these authors vary in their techniques of application in this step of preoperative medication, they all feel that such medication should produce a calming effect upon the patient, but should allow the patient to remain conscious so that he may adequately respond to audiometric testing. (Surgical pure-tone audiometric testing is discussed in Section VI of this chapter.) 38Victor Goodhill, "Trans-incudal Stapedolysis for Stapes Mobilization in Otosclerotic Deafness," The Laryngo- scope, 65:696, August, 1955. 39Ibid. uORosen and Bergman, op.cit.,p.198. ulScheer, op. cit., p. 513. 122 Preoperative Physical Preparation of the Patient After the patient has been taken into the operating room, he is placed on the operating table. In this respect Scheer says: The patient is placed on his back on the operating table, with the face toward the opposite shoufiger, thus bringing the selected ear into position. Hair preparation is kept at a minimum Goodhill states: The hair is not shaved but is usually kept out of the surgical field by the use of a modified bathing cap or adhesive tape.43 Scheer appears to agree with Goodhill regarding the lack of necessity Ra‘shaving the hair and applies Vasoline with a tongue depressor in order that the hair can be kept away from the auricle.uu As previously stated the author had the opportunity to witness three of Dr. Schuknecht's operations. The author observed that Schuknecht neither shaved the hair, used adhe- sive tape or applied Vasoline to keep the hair away from the surgical field. Schuknecht placed a square piece of material, with a hole in the center, over the surgical area. The ear protruded through the hold. He then placed regular green surgical draping over the material, allowing only the ear to be exposed. 42Ibid. 43Goodhill, "Trans-Incudal Stapedolysis for Stapes Mobilization on Otosclerotic Deafness," op. cit., p. 696. “AScheer, op. cit., p. 513. 123 The cleansing of the ear canal involves the following procedures, according to Goodhill: Cerumen, dead epithelium and crusts are carefully removed from the external auditory canal by the surgeon; the canal is filled with a 1-1000 aqueous zephiran solution. . . . The purpose of thiszqueous zephiran preparation is two fold: a. It is designed for antiseptic preparation; b. It servez to create edema (swelling) of the tympanic membrane. 5 The elevation of the tympanic membrane is an impor- tant stage in the stapes mobilization surgical procedure. Goodhill is of the opinion that by introducing aqueous zephiran into the ear canal and therefore creating swelling of the tympanic membrane, the elevation of the tympanic membrane is made easier with little danger of perforationf‘6 The author observed that Schknecht cleansed the surgical field by first washing the auricle and surrounding skin with antiseptic soap. He then rinsed the auditory canal three times with an antiseptic solution. The solution was left to soak in the canal for a short period of time during the last two rinses. Schuknecht feels that by letting the solution soak, it sterilizes the area effectively, pre— pares the walls of the auditory canal for incision and allows for easier tympanic elevation.47 As a final cleansing procedure, Schuknecht used a suction to remove any excess fluid, particles of dead 145Goodhill,‘"Trans-Incuda1 Stapedolysis for Stapes Mobilization of the Stapes," op. cit., p. 696. 46Ibid, 47Schuknecht, op. cit., April 27,1957. 124 epithelium and cerumen from the auditory canal. He found it necessary to clip the hairs in the auditory canal of one of the patients before surgery could take place. IV. ANESTHESIA A local anesthetic is administered in the stapes mobilization surgical procedure. As in other phases of this procedure, there is no standard method for the administration of anesthesia. Many surgeons have developed their own individual techniques. Although these techinques are similar in goals, they are dissimilar in solution components and methods of injection. Solution Components The following information will concern a review of the anesthetic solutions used by some otologists in the stapes mobilization operation. According to Rosen and Bergman an adequate solution consists of: One to 2 cc. of a mixture of 3 parts of 2% lidocaine (Xylocaine) hydrochloride to 1 part of epinephrine 48 chloride, 1:1000, is injected in equal amounts. . . Goodhill states that the cutaneous lining of the bony canal wall is adequately anesthetized by: . . . a mixture of 2 per cent xylocaine, three parts and 1:1000 adrenalin, one part. . . . A total of less 48Rosen and Bergman, "Mobilization of the Stapes for Otosclerotic Deafness," op. cit., p. 198. 125 than lcc. of this mixfipre is needed for adequate local anesthesia. . . Myerson's technique involves: . . . injection of an average of 2 cc. of procaine, 1% solution, each ounce (30 cc,) of which contains 12 minims (0.75 cc.) of ppinephrine hydrochloride has been found satisfactory. Scheer explains: A mixture of 2% lidocaine (Xylocaine) hydrochloride 3 cc.), hyaluronidase and epinephrine hydrochloride 1 1 cc. of 1:1000 solution) is used for local anesthesia? Myers and Ronis describe the solution they administer as being composed of: . . . 2% lidocaine (Xylocaine) (3cc. to which is added 1 cc. of epinephrine, lzlogg). Usually about 1 cc. of the solution is needed. Although all solutions described above differ from each other in composition, they are all intended to anesthe- tize the entire cutaneous bony canal lining and the tympanic membrane, so that surgery can be performed with as little pain as possible to the patient. 49Goodhill, "Trans-Incudal Stapedolysis for Stapes Mobilization in Otosclerotic Deafness," op. cit.,p. 697. 50Myerson,'"Mobilization of the Stapes for Oto- sclerosis," op. cit., p. 86. 51Scheer, op. cit., p. 513. 52 Myers and Ronis, loc. cit. 126 Mg of Inject-ion All methods of injection reviewed by the author are intrOduced into the walls of the external auditory canal. Such injections vary in number and exact points of attack, depending upon the technique‘of the surgeon administering the injections. The method of injection employed by Rosen involves subcutaneous injections into the posterior, superior, anterior, and inferior walls of, '" . . . the external canal at the junction of the cartilaginous and bony canal.“53 Therefore, Rosen administers four injections for anesthetic purposes in the stapes mobilization surgical procedure. Goodhill's method is similar to Rosen‘s. Goodhill states that the solution is: . .. injected with a 3-inch 22 gauge short beveled needle at the four points of the circumference of the external canal, at the jungpion of the bony and cartilaginous canal walls. Myerson‘s technique varies from those mentioned above in that he feels that one injection is sufficient for most Purposes. He states: The injection is made posterosuperiorly into the r‘e‘troauricular fold at the junction of the cartilaginoup and osseous canals. A single injection will suffice. 5 K 0t 53Rosen and Bergman, “Mobilization of the Stapes for osclerotic Deafness," op, cit., p. 198. 54Groodhill, "'Trans-Incudal Stapedolysis for Stapes Mobilization in Otosclerotic Deafness," op. cit., p. 697. Sis .. 55Myerson, '"Mobilization of the Stapes for Otosclero- QE. cit., p. 86. 127 However, this author adds that in cases where the operating surgeon does not wish to wait for the solution to infiltrate widely '". . . additional injection at a point corresponding to the mid-line of the roof and floor of the . .1156 canal may be added. . Scheer employs the use of a 24-gauge needle, which he carries down to the bone. He explains, ". . . the anesthetic is injected posteriorly and superiorly. It is desposited superficially in the inferior location."57 Myers and Ronis use a 25-gauge needle in their tech- nique. In conditioning the skin surface of the auditory canal for the injections, they employ an ear speculum. An ear speculum is a small metal funnel through which the Operation is performed by most surgeons. Myers and Ronis explain their technique in the following manner: The ear speculum is pressed against the membranous canal. This forms a ledge into which the needle is inserted. A small wheal is raised, and the point of the needle is directed against the osseous canal. The entire canal is circularized in this manner with no attempt to inject the osseous canal at this time. The Skin lining of the canal is very thin and insertion 0f the peedle directly would tear the skin of the canal .5 After the membranous canal is circularized with the aneSthetic two times, these authors add: By this time the skin is thickened and a fine beveled needle (25—gauge on a tuberculin-syringe) 18 93.81137 in‘Eier‘ted into the skin lining of the osseous canal.59 \N 56 Ibid. 57Scheer, op. cit., p. 513. 5 8Myers and Ronis, op. cit., p. 3100 59Ibid. 128 In administering their technique of anesthetic injection, Myers and Ronis state that the injection is made slowly in small amounts and therefore: . . . the operator can watch the solution spread irito the skin of the osseous canal and over the drum rneunbrane. Some of the solution probably gets into 6 'tkne middle ear and anesthetizes the mucosal surface. 0 After the anesthetic has been administered the surgeon prepares to proceed with surgery. V . SURGI CAL TECHNI QUES That the stapes mobilization surgical procedure should be performed by the skilled otologic surgeon is general ly agreed upon by all authors reviewed in this sec- tion of the study. Before the operating surgeon can supply the stapes mobilization surgical techniques effectively, many otologists feel that he should have a considerable amount of practice. Rosen and Bergman explain: This operation appears deceptively simple, yet learning to perform it skillfully is not, because all maneuvers are restricted by the limits of the bony exter'nal canal. One must learn to do the operation Skillfully through external augitory canals which are Wide, narrow, or tortuous. In this respect, Goodhill states: This is not simple surgery. Experience seems to 1C“ate that this procedure in its present early \N— ind Ibid. sclemsilRosen and Bergman, “Restoration of Hearing in Oto- An Anal 3 by Mobilization of the Fixed Stapedial Footplate. ysis of Results," op. cit., p. 232. .- 129 form should be limited to the otologic Eurgeon who is skilled in fenestration surgery. . 2 According to Goodhill, one reason for his above statement is that such a surgeon has had the specific ana- tomical training and has the surgical dexterity necessary for stapes mobilization.63 In order that the surgeon can properly prepare him- self, Rosen and Bergman state: For the mobilization operation even the skillful surgeon should perform the operation on at least 50 fresh6fiadavers before the first patient is operated upon. However, Myers and Ronis explain: While a degree of proficiency can be obtained with cadaver practice, the feel of mobilizing the stapes can only be agcomplished on the living patient with otosclerosis. 5 So that the surgeon has adequate visualization of the surgical field when administering his surgical techni- ques, magnification is employed, usually through an ear speculum. Meurman and Meurman state: 62Goodhill,'"Trans-Incudal Stapedolysis for Stapes Mobilization in Otosclerotic Deafness," op. cit., p. 695. 63Ibid. 64Rosen and Bergman, "Restoration of Hearing in Oto- sclerosis by Mobilization of the Fixed Stapedial Footplate. An Analysis of Results," op. cit., p. 231. 6 5Myers and Ronis, o . cit., p. 307. 130 The magnification requires special attention. The operation can be performed with a pinocular loupe, magnifying 2-1/2 to 3 times. . . 6 However, when using this binocular loupe these authors said: It is a disadvantage that, when working through an czar-speculum, binocular vision is much hampered. . . ELowever, when the latest model of the Ziess binocuéar alicroscope is used, binocular vision is unimpeded. The author found that various types of magnification equipnment are used by different surgeons, however, most surgeuons reviewed by the author used the latest model of the Ztiess binocular microscope. This piece of equipment has a.‘built-in light, and allows the surgeon to work without the use of a head-light. As previously described, the ear speculum is a Sma11_ Inetal funnel that is inserted into the external auditrc>ry canal. According to Derlacki, Shambaugh and Harri- son, "'The entire surgical procedure is performed through an eéaax~ speculum. . {"68 From the gathered information it “amiss apparent that most surgeons use the ear speculum. }kme‘\7<2>1:h the ear speculum and Ziess binocular microscope in \ 67Ibid. 66Meurman and Meurman, op. cit., p. 166. WEE: 68Eugene L. Derlacki, George E. Shambaugh, Jr., and :9” H. Harrison,'"The Evolution of a Stapes Mobilization T ecuIlique,“ The pamsoscepe: 62:431: May, 1957' . . I! liIlcblltl.‘ 131 his stapes mobilization operations.69 The surgical techni- ques of the various surgeons, reviewed by the author, will be d1 scribed within this section of the study. Such techni- ques vary from each other in administration, but all are performed in an attempt to mobilize the stapes fOOtplate. The following discussion will be divided according to the five major phases of stapes mobilization surgery: the incision, entrance into the tampanic cavity, exposure 01‘ the middle ear structures, mobilization of the stapes footplate, and closure of the tympanic cavity. 3‘29 Incision There are two types of incisions administered in the Stapes mobilization surgical procedure, according to the material reviewed by the author. Also, it was discovered that one surgeon performs this procedure without an incision. One type of incision begins at 9 o'clock (posteriorly) and ends at 3 o'clock(anteriorly) in the wall of the auditory Canal - The other type of incision begins at 12 o'clock (Superiorly) and ends at 6 o'clock (inferiorly) in the skin of the canal wall. In classifying these incisions, the author is con- Side J3‘21ng only the incision made in the right ear. 9 o‘clock to 3 o'clockfiincision. The information reviewed by the author revealed that Rosen and only a few 0 ”1335‘ surgeons administer the 9 O'clock t0 3 O'Clock 1nCiSi°n-- \\ 69Schuknecht, op. cit., April 27, 1957. 132 Rosen describes his method of incision in the fol- lowing manner: An incision is made through the skin over the bony c:ana1 wall, beginning at about 9 o'clock and continuing cLownward and around to 3 o'clock on the right ear and \rice versa 8n the left, about 6 to 7 mm. external to tihe drum. 7 Meurman and Meurman state in regard to the incision: It is important to make the incision in the canal vvall, as Rosen advises, sufficiently lateral to the Cirum, more than 5 mm. from the margin. Figure 12, page 135, illustrates this type of inci- sion administered in the right ear. 12 o'clock to 6 o'clock incision. The author found that ssome surgeons reviewed in this area, do not strictly adhelree to the method of a 12 o'clock to 6 o'clock incision. However, all types of incisions that will follow are unique fktml t:he above described 9 o'clock to 3 o'clock incision in trhey begin at 12 o'clock in the superior margin and end These that in tlfiee inferior margin of the auditory canal wall. hufl.ss;1ons involve the posterior wall surface. Myers and Ronis explain: The incision is started in the posterior-superior C2anal wall about 4-6 mm. from the drum edge . . . at 22 o'clock, with the use of the short process of the 1'1'?l£s:.1leus to denote 12 o'clock . . . proceeds around - . to 5 'clock in doing the right ear, and to 7 ‘:> ‘clock in the left ear.72 \ . 0U) 70Rosen and Bergman, "Mobilization of the Stapes for S Qlerotic Deafness," op. cit., p. 198. 71Meurman and Meurman, op. cit., p. 167. 72Myers and Ronis, op. cit., p. 310. 133 According to these authors the incision is made in smalgl steps,'". . . making each cut through the skin and into the osseous canal."73 Derlacki, Shambaugh and Harrison describe their method of making the incision: The skin of the posterior osseous meatal wall is :lncised from approximately 12 o'clock to 6 o'clock, laeginning close to the annulus and swinging lateralward 51 good 34mm. from the annulus in most of its U-shaped course . Scheer explains: An incision is made in the skin of the bony canal vvall 6 to 7 mm. external to the tympanic membrane, exxxending from 12 o'clock to 6 o'clock on the posterior vmall.. . . Since the skin of the external canal is tfluickest in its superior portion, the incision must be =31:arted at 12 o'clock75rather than below, since this VViJJ.prevent tearing. Myerson creates the 12 o'clock to 6 o'clock incision in the following manner: The incision is made with two knives; one cuts 1Tt3rward and backward along the midline of the roof and Ileoor of the ear canal, while the other Joins these illicisions by cutting from side to side. The Juncture <:>f'these incisions is rounded, not angular. Goodhill describes his incision: The incision in the posterior half of the canal skin is omega shaped, starting superiorly at about the Junction eetween the pars tensa and pars flaccida and ending at ‘1211e inferior aspect of the annulus. The apex of the ‘CDwnega is at the lateral extremity of the posterior bony C: anal wall .77 \ 73Ibid. 74Derlacki, op. cit., P- 431- 75$cheer, op. cit.,pp. 513-514, 76Myerson,"Mobilization of the Stapes for Otosclerosis," W” p. 86. 77Goodhill, op. cit., p. 697. .lll"ll. .Ialfldll‘.l. .- 1314 Figure 13, page 136, illustrates this type of incitsion.created in the right ear. No incision. Dr. Mervin C. Myerson of Beverly Hills, Caliifcmnia, has developed a stapes mobilization technique 'by wkiich, an incision is not necessary. This method of stapeas mobilization will be described within the discussion of trie “mobilization of the stapes footplate," later on in this section of the study. Purpose of the incision. Although the above described incisions differ from each other in regard to the area in— xmflxmeci, they are all attempted with the purpose of preparing the Eslcin.flap for its elevation with the tympanic membrane in stic:h a manner that they do not suffer undue injury. It should not be assumed that these incision techni- ques Eire the only ones employed by operating surgeons in Stap€3+ss mobilization. The type of incision created depends lumn 1:he surgeon performing the operation. It is quite p0ssil—ble that other techniques have been developed or are behlég; developed at this moment. However, the author found inmI‘firuation concerning only the methods discussed above. E . imalééizlce into the Tympanic Cavity This phase of the stapes mobilization operation con- c 9mg the separation of the skin flap from the bony canal .i“-‘~__ Out 78Mervin C. Myerson, "Mobilization of the Stapes With- :[3r1cision," A.M.A. Archives pf Otolaryngology, 64:373, Ju 137~"‘I)ecember, 1956. S‘1 ,‘.1 vi ~l - 7‘ Q 135 wall, the elevation of the tympanic membrane from its cir- cular groove,and the folding of these combined components so ‘that the tympanic cavity is exposed. This procedure can be difficult, depending upon the characteristics of the partic- 'ular ear canal involved. Rosen explains: . . . in many specimens the posterior bony canal wall is concave, and the anterior canal wall is convex. Separating the skin from the bony wall without tearing it or injuring the drum in such cases is difficult.79 The techniques of performing this phase of' stapes :mobilization surgery, reviewed by the author, will be con- sidered in the following discussion. -The methods will be arranged under two classifications, the superior method, and the anterior method. The superior method. The superior method follows the 9 o'clock to 3 o'clock incision, and concerns the dissection and folding of the skin flap and tympanic membrane super- iorly. According to the method employed by Rosen, Figure 12, the skin flat is separated from the bone, beginning from gure 12. The righ ea“’ canal after incision, the the incision to the base of dissection of the skin flap and tympanic membrane, and the eardrum. At this point, folding according to the superior method. '". . . the drum is finally 79Rosen and Bergman, "Restoration of Hearing in Oto- sclerosis by Mobilization of the Fixed Stapedial Footplate. An Analysis of Results," op. cit., p. 232. 136 lifted out of its sulcus and reflected upon itself like an .1180 apron . The anterior method. The anterior method is employed after the 12 o'clock to 6 o'clock incision and involves the dissection and folding of the skin flap and tympanic membrane anteriorly. Myers and Ronis offer the following words of advice to any surgeon employing their method of performing this phase of the operation: Before any attempt is made to dissect the flap, be sure the knife can run all around the entire incision and bite into the bony ear canal. Any shreads of the skin the knife does not separate can be cut with8a small iris scissors or with Bullucci's scissors. FELgure 13. The right ear canal after incision, the dissection of the skin flap and tympanic membrane, and folding according to the anterior method. \ OtQSCl 0Rosen and Bergman, “Mobilization of the Stapes for er‘Osic Deafness,‘ op. cit., p. 198. 81Myers and Ronis, loc. cit. 137 Myers and Ronis proceed with their dissection around the entire incision, ". . .5 o'clock in doing the right ear, and to 7 o'clock in the left ear.82 These authors add: When the region of the sulcus is reached, one can feel the dissecting instrument dip into the sulcus and lift the fibrous annulus out of its bed. The dis- section then proceeds until the end of the osseous canal, where the middle ear is gntered. . . and the eardrum.easily folds on itself. 3 The technique employed by Derlacki, Shambaugh, and Harrison is described as follows: The incision and initial elevation are carried. . . down to the sulcus tympanicus where the fibrous annular ligament of the ympanic membrane lies in the bony groove. . . . The annular ligament is then elevated from the sulcus with the angled elevater . gently pushing this instrument directly inward at repeated points along the sulcus . . . and gfle tympanic membrane is folded forward upon itself. . Sheer's method is quite similar to the above described procedures. He explains: With elevators of various sizes, the skin is lifted from the bony canal down to the annulus of the tympanic membrane. The fibrous annulus is then lifted out of its sulcus, and the tympanic membrane is folded anteriorly like an apron, thus exposing the middle ear.85 To facilitate the separation of the skin flap from the canal wall, Myerson, moistens the area between the flap and bony wall with, ". . . 2 minims (O.12cc.) of saline or 82Ibid. 83Ib1d. 84Derlacki, Shambaugh and Harrison, loc. cit. v 85Scheer, o . cit., p. 513. 138 .186 epinephrine hydrochloride solution. He applies this solution by saturating small flat, elongated pieces of cotton with it, and places these pieces of cotton in the desired 87 areas - The application of the solution is carried out period- ically during the elevation procedure. Myerson describes his method of elevation: The flatter elevator is better for beginning the elevation. It is usually started posteriorly. Gentle pressure is made between the flap and the bony wall, using the dissector or suction tube . . . this prevents tearing of the flap. Elevation is continued until the point of attachment of the drum is reached. At this point the more curved of the elevators is insinuated into the sulcus to which the fibrocartilaginous rim of the tympanic membrane is attached. The membrane is cautiously lifted; . . . and the posterior half of the membrane reflected anteriorly so that the gorrespond- ing portion of the tympanic cavity is exposed.8 Goodhill states, "The elevation of the dermal-perio- steal flap can be accomplished rapidly but should be done With magnification. . . ”"89 He adds: The elevation is carried medially until the margin of the annular sulcus is reached. When the margin of the tympanic sulcus is reached, a round angulated elevator is used to enucleate the annulus fibrous fI‘Om the sulcus. Following the enucleation penetration of the tympanic air space is accomplished.9<5 8 Sis .u ESMyerson, “Mobilization of the Stapes for Otosclero- 22. cit., p. 86. 87M- 88%., p. 87. 89(7roodhill, '"Trans-Incudal Stapedolysis for Stapes Mo blejzation in Otosclerotic Deafness," op. cit., p. 597- 901nm. 139 Control of bleeding. There is a certain degree of bleeding that results during the dissection of the skin flap from the bony canal wall. Scheer says, '"As a rule, the only time bleeding is encountered is before the tympanic membrane is reflected forward."91 To insure a dry field, small dental cotton balls occasionally saturated with epinephrine are used as wipes. Narrow-gauge spinal needles (which are beveled flat) are used as suction tips, should they become necessary. Derlacki, Shambaugh and Harrison, control the bleeding by: . . . placing tiny cotton balls moistened in the xylocaine-adrenalin solution between the elevated Skin and the bone, and applying suction. Any remaining bleeding points are controlled by electro-cautery applied to the fine suction tip. 3 Myers and Ronis do nothing to control the bleeding, until they have reached the middle ear. They explain: If the surgeon moves along, by the time the middle ear is reached, most of the bleeding stops. When the dissection is completed, the blood is aspirated and the area mopped with small cottfin pellets soaked in the epinephrine solution (1:1000) . 9 The entrance into the tympanic cavity is one of the critical points in the stapes mobilization surgical procedure, according to Schuknecht. If this procedure is not adminis- tered with proper precaution, it is possible that the eardrum “- 91Scheer, op. cit., p. 514. 92Ibid. 93Derlacki, Shamburgh and Harrison, loc.£it. 9L‘lMyers and Ronis, loc. cit. 140 may be permanently perforated. Schuknecht stated that of the one hundred and fifty stapes mobilization operations he has performed, not one resulted in a permanently perforated eardrum.95 gargosure of the Middle Ear Structures After an entrance has been made into the tympanic Catertzy it is important that the surgeon have an unimpeded ldeatv' (of the middle ear structures, principally, the incudo- 8fatpeciial Joint, the stapes tendon, and the component parts or tzléiea stapes. Derlacki, Shambaugh, and Harrison explain, M: - .. we have found that direct visualization of as much 0f “trifle: footplate as possible gives the best control of the mObi l ization procedure. . {"96 Two elements that may obstruct the surgeons view ans .: ‘the bony rim of the auditory canal, and the chorda Wrap Eini nerve . The bony canal rim. According to Scheer, the size zmc1 Esliape of the patient's auditory ear canal will determine hcyvq lxruch.of the ". . . incus and stapedius tendon will be 1 mediately visible on lifting the drum"97 Sheer further adds: 95 Schuknecht, op. cit., April 27, 1957. 96Derlacki, Shambaugh, and Harrison, op. cit., p. 433. 97Scheer, op. cit., p. 514. 141 The greater the forward angulation of the canal, the less visible will be the long arm of the incus and stapedius tendon. Occasionally it will not be possible to see eggn the lower end of the long arm of the incus. . If proper visualization is impeded by the structure (if the auditory canal, after the tympanic cavity has been equcnsed, a portion of the posterio-superior bony rim of the Ceu1511; is removed. In this respect, Scheer states, "The Ing7c>zéity of cases require that some bone be removed to get PPope r exposure .'" 99 In cases involving an ideal canal for stapes mobiliz- ati<2xr1., the incudostapedial Junction is seen first after the tMmI:LeaJriic cavity is exposed. Rosen and Bergman state, "In mmcrr '835% of the cases the incudostapedial Junction is seen at Once.'"100 Goodhill reports that his experience with “RJ;>€3:E3 mobilization revealed that after the tympanic cavity 1mg ‘tbeeen exposed: . . in at least 50 per cent of cases a direct ‘JTLew of the entire incudo- -stapedial Joint will be <2>13tained, along with the chorda tympani nerve, stapedial 12€3ndon, part of the posterior stapedial crus and part Of the anterior crus. Although Rosen and Bergman state that the incudo- Sta-pedial Junction is seen at once in over 85 per cent of ROSen's cases, these authors add: \ 98Ibid. 991bid. Ot 100Rosen and Bergman, "Mobilization of the Stapes for OSclerotic Deafness," o.p cit., p.198. 101Goodhill,"Trans-Incudal Stapedolysis for Stapes V§§$ilization in Otosclerotic Deafness," op cit., p. 698. 1H2 about 2 to 3 mm. of the very edge of the posterior bony canal, Just external to the incus, is removed in order to get a much wider exposure, especially of the stapedial tendon, which is inserted into the neck of: the stapes.102 As previously inferred, Rosen's initial incision and elevation procedure exposes the inferior half of the auditory cannail opening to the tympanic cavity. The 12 o'clock to ES (3"clock incision and elevation procedure exposes the whole p0531363rior half of the canal opening. Therefore the author aSESIJJTHBS that Rosen's point of attack, in regard to the removal of t:lj£3 bony canal rim, is directed in an area that is infer- ior‘ 't:<3 the posterio-superior area involved in the following DPC>c2<3sterior-superior rim above the exit of the chorda 1::ympani nerve to expose all of the stapedial tendon.103 ‘Myerson states: Removal of bone should be confined to the region above the point of exit of the chorda tympani nerve karom the facial nerve in order to avoid inJuring the 1?acial nerve. 4 Goodhill says: If . . . clear visualization is not easily obtained, fl.t is necessary to obtain adequate exposure by removal ()f sufficient posterior-superior bony annular quadrant to make this possible.10 \ 102Rosen and Bergman, “Mobilization of the Stapes for C) . t:‘3S5clerotic Deafness," op. cit., p. 198. 103Derlacki, Shambaugh, and Harrison, loc. cit. s1“ 104Myerson,‘"Mobilization of the Stapes for Otosclero- ‘3 a?" M p- 88- 105Goodhill,'"Trans-Incudal Sta edolysis for Stapes 7Whilization in Otosclerotic Deafness;' ppp_gip., p. 700. 143 The author found that the instrument used to remove the bone from the canal rim depends upon the particular SUr‘geon performing the procedure. Schuknecht employed the use of a long slender instrument with a barbed head on one end, called a curette.106 It was also revealed that other surgeons use this instrument. In order that the ossicular chain is not inJured during the removal of the bone from the canal rim, Scheer eJtplajns, '"If the curetting is done within out, there is little danger to the underlying ossicles.‘"107 It is necessary that the surgeon keep the operating field free from bone chips and blood that may accumulate during surgery. In this phase of the operation, the col- lee 1: 111g of bone chips in the surgical field is a particular Problem. To remove these bone chips, Myerson states, °". sue t ion with fine tubes is applied when necessary to keep the Operative field clean."108 Chorda tympani nerve. The anatomical placement of t he chorda tympani nerve has created problems in some cases, a. s far as the proper visulation of the middle ear structures \ 106Schuknecht,1oc. cit. 107Scheer, op. cit., p. 515. sq: 108Myerson, '"Mobilization of the Stapes for Oto- lerosis,“ op. cit., p. 88. 1144 is concerned. In this respect, Scheer states, "The chorda tmeani nerve may be in such a position as to block complete Visualization of the incudostapedial Joint. .'"109 Myers and Ronis explain: The chorda tympani nerve is often encountered but seldom has to be disturbed since it rests in the bony ledge of the canal, at times it must be displaced from the line of Vision.110 There are two methods which are used for the displace-' melj t: (of the chorda tympani nerve, if it presents itself as an obstruction to proper visualization. One method involves mezreefllgy'pushing it out of the line of vision. The other method concerns the severing of the nerve. Derlacki, Shambaugh, and Harrison state: Depending upon its position, the chorda tympani nerve may be kept in its superior position1 gis- ];>1aoed downward, or if necessary, removed. 1 Goodhill says, in reference to the displacing of the Ch'(3’31'5'WE‘1a.tympani nerve: . . . the chorda tympani nerve . . . can usually 136 pushed aside with little difficulty. It is .IFarely, if ever, necessary to cut this nerve.112 According to Scheer, every precaution should be made t O perserve the chorda tympani nerve, '". . . since severing it Will produce changes in taste. . {"113 \ 109Scheer, op. cit., p. 515. llOMyers and Ronis, 10c. cit. lllDerlacki, Shambaugh, and Harrison, loc. cit. MC) 112Goodhill,'"Trans-Incudal Sta edolysis for Stapes tDfiLlization in Otosclerotic Deafness;‘ op. cit., p. 700. 113Scheer, op. cit., p. 515. 145 Providing the situation warrants the severing of the <fimrda tympani nerve, Scheer explains: If the nerve is cut against the canal wall with a curette, there is no pain. Should it be picked up, stretched, and then avulsed, there is a sharp pain that shoots down to the neck and the mandible. 1 When Scheer was forced to cut the chorda tympani nerves cxf‘ flis patients in the stapes mobilization operation, he fictirici that such patients experienced a,'" . bitter, met:£1:Llic taste that remained in their mouths, and that food, though in itself tasteless on that side, aggravated the bitztzeecrness;"115 Eight months after the operation, Scheer “ports that these patients, "‘. . . are still slightly con- scious of some change in taste, but they do not have the cons tant bitterness in their mouths."116 When the middle ear structures have been adequately expo Bed, the surgeon then proceeds to attempt to mobilize the S tapes foo tplate . @32£!;E£gization_of the Stapes Footplate Myerson refers to a book written by Helmholtz entitled, EEHEi, lgyechanism pf the Ossicles pf the Ear and Membrana Tympani, tbarisiated by A. H. Buck and N. Smith, New York, William Wood and Company, published in 1873. Myerson reports that Wkleerl- the stapes is functioning normally, according to \ 114 115 116 Ibid. Ibid. Ibid. 1116 E elnlholtz the ". . . excursions of the stapes at its foot- D late are from 1/18 and l/lAL mm.“117 Therefore, according t 0 MLYerson: This emphasized the very small field involved in mobilization of the stapes. It is obvious that a great deal 05 force is not necessary to mobilize this structurefLl However, when considering the force necessary to 11101311 :Lze the stapes footplate, it is important that the Ciégreee- (3f ankylosis in the footplate region be taken into a“Curt; t. - In this respect Scheer states, '"The amount of that is needed to mobilize a stapes depends on the dagr‘ee o f fixation ("119 The mobilization techniques employed by the surgeon, also depend upon the extent of stapes fixation. Goodhill explain 8 g l The actual technical maneuvers necessary for adequate fys is depend primarily upon the pathologic status of the c>:Lving rod is placed in contact with the forked instrument after the forked instrument has been placed over the incudo- Stapedial Joint. Figure .15 illustrates this method of mob 1 l ization . Figure 15. Indirect method of mobilization with pressure applied to the incudostapedical Joint. The Myerson technique. \fi 62Myerson, “Mobilization of the Stapes for Otosclero- $3 1%," op. cit., p. 86. 1631bid. 159 Myerson states: The vibrations are delicate or coarse, and generate force and amplitude according to the part of the re- volving rod in contact with it.164 Force and amplitude also depend upon the number of revolutions per minute that the dental handpiece causes the rod to rotate. In this respect, Myerson explains: One should rely upon the three speeds supplied by the foot switch. . . . At low speed approximately 1500 rpm are delivered; with medium speed approximately 5000, and with high speed approximately 9000 rpm are produced. . . . The low and medium speeds should be tried first. If they do nog prove successful, the high speed should be used.1 5 Myerson reports from clinical experience,'". . . 9000 rpm will mobilize any stapes that can be dislodged, short of causing irreparable damage."166 Myerson did not state whether or not the above described procedure is effective in cases involving atropic or weakened crura. Goodhill's application of mobilization force is directed through the incudostapedial Joint,with the mobilizer placed on the incus, if this Joint does not appear dangerously loose during the initial mobility test. Goodhill explains: If force application seems feasible by this techni- que (pressure in the areas of the incudostapedial Joint) interrupted delicate digital vibrato pressures are transmitted through the incudostapedial Joint to the footplate region in a direction determined largely by resistance encountered.l 7 154Ibid., p. 89. l651b1d. leélkié- 167Goodhill,'"Present Status of Stapedolysis," pp. cit., p. 341. ———.——— 160 However, this author further adds: . . . the direction of force is usually in a poster— ior direction. . . toward the posterior limb of the footplate to produce a surgical fracture either through the otosc erotic bone . . . or through the footplate itself.1 The above described direction of force is applied if the otosclerotic bone growth appears in the anterior area of the footplate. However, the direction of force will be in a superior direction . . . if greatest resistance is encountered in that direction on palpation."169 Figure 16. Indirect method of mobilization with pressure applied to the incus and directed through the incudostapedial Joint. In reference to the possible dislocation of the incudo- stapedial Joint, Goodhill explains: Incudostapedial dislocation will occur more fre- quently when force is in an inferior direction, pulling the stapedial capitulum away from the anchored incus. There appears to be greater tolerance for slight rotation of the stapes superiorly than inferiorly. a combined maneuver in a posterio-superioi girection will be effective in a maJority of cases. 7 168Ibid. l691bid., p. 42. 170Ibid. *_ # 161 When Derlacki, Shambaugh and Harrison first began 'pearzrfifforming the stapes mobilization surgical procedure, they err:g>21.oyed the previously described Rosen method (applying p>1r:r‘ the posterior edge of the capitulum of the stapes .11 l78 the incudostapedial Joint is too freely nicawxrzaLble . . . tlrlea The incus is not used for mobilizing movements if the incus is eccentrically placed on capitulum of the stapes . . . the incus is split or dislocated at the time pressure is applied . the incus is not at ri l7ght angles to the under- lying crura of the stapes.1 then pressure is applied to the head of the stapes, it is possible that the head may split For such cases House designed, '". . a small capitulum cup . . . to fit over t3r1€3 entire stapes head through which manipulating mo tion 8 czould be carried out."180 Goodhill, also, directs the mobilization pressure againss13, ‘the head of the stapes, if the initial mobility test SI"hams that the incudostapedial Joint is loose and sub- JeCt to dislocation.181 :Ekefore applying the point of the mobilizer to the hea ‘1 C>iT the stapes, Goodhill explains ins- . Ca. er . the lenticular process is moved away from its r1e tion upon the capitulum, and only sufficient Ditulum area is exposed to permit applicatio EBOf the eE3