A METHOD FOR SURGiCAL CORRECTEON 0F RECURREWT URETHRAL BLOCKAGE EN THE MALE CAT UTiLIZlNG A PELWC SYMPHYSEOTDMY APPROACH Thesis for the Degree of M. S. MICHiGAN STATE UNIVERSITY JOE KASHNER 1968 ”film W. ' f?" = ' l 'O _I 3: I. If? Eli->13“ Michigan 8mm ~ ' University ABSTRACT A METHOD FOR SURGICAL CORRECTION OF RECURRENT URETHRAL BLOCKAGE IN THE MALE CAT UTILIZING A PELVIC SYMPHYSIOTOMY APPROACH By Joe Kashner The purpose of this study was to evaluate a technique for surgical correction of recurrent urethral blockage in the male cat° The surgical procedure was used on 15 normal research animals and 20 clinical cases of urethral obstruction which were admitted to the Michigan State University Veterinary Clinics. Since the most common site for urethral obstruction in the male cat is in that portion of the urethra which extends from the glans penis to the bulbourethral glands, most surgical procedures for correcting this condition have entailed attempts to circumvent this area. The technique studied in this experiment utilizes a median pelvic symphysiotomy approach which provides maximal exposure of the surgical area. 'With this approach, it is possible to amputate the penis, remove the penile urethra, and anastomose the pelvic urethra to the base of the prepuce. The normal preputial Opening is preserved and utilized for urine passage. The pelvic symphysis is closed with stainless steel wire and postoperatively supported by immobilizing the rear legs with hobbles for 48 hours. Placement of a retention catheter, which is removed on the fourth postsurgical day, is recommended to support the anastomosis site° For best results, those patients which are obstructed or suffering from acute urethritis should be treated to minimize the urethral Joe Kashner inflammation before surgery is performed. Since the success of this surgi— cal procedure depends on the patency of the anastomosis, the viability of the urethral tissue is very important. Histological examination of the anastomosis site in the experimental animals revealed no serious pathological changes. Isolated areas of inflam- mation were noted, apparently caused by the surgical gut which was used. Urethrograms indicated that various degrees of urethral narrowing can be expected at the anastomosis site. Bacteriological samples taken from the clinical cases did not show evidence of any specific bacterial frequency; however, the majority of these animals were on antibacterial therapy prior to collection of samples. The chemical content of the obstructing material was analyzed in 6 of the 20 clinical cases. In all cases the material was composed of cal- cium, ammonium and magnesium phosphates. The major complication of the procedure was leakage of urine at the anastomosis site. The cause of death in 3 clinical cases was attributed to this problem, which can be minimized by proper selection of the surgical patient. Disruption of the anastomosis site from urine leakage also occurred in one experimental animal which would indicate a potential com— plication even in those clinical animals determined to be in good physical condition. Two other clinical deaths which occurred were unrelated to failure of the anastomosis. Urethral stricture observed in 2 clinical cases was successfully treated using dilators. Transient hematuria develOped in 2 cases, both of which responded satisfactorily to antibacterial therapy. Joe Kashner The major advantages of this procedure are attainment of maximal exposure of the surgical area, and utilization of the anatomical components necessary for urination to occur through the preputial orifice. Surgical irrigation of the bladder was not incorporated into this procedure; how- ever, the abdominal approach provides ready access to the bladder should irrigation be indicated. A METHOD FOR SURGICAL CORRECTION OF RECURRENT URETHRAL BLOCKAGE IN THE MALE CAT UTILIZING A PELVIC SYMPHYSIOTOMY APPROACH By Joe Kashner A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Surgery and Medicine 1968 ACKNOWLEDGEMENTS The author wishes to thank the graduate degree committee members, Dr. W. 0. Brinker, Dr. R. G. Schirmer, Dr. R. F. Langham, and especially Dr. W. F. Keller, Department Chairman, for their assistance and guidance throughout the various phases of this project. A special note of appreciation is due the many students who assisted in the surgical aspects of this experiment. The assistance of Dr. U. V. Mostosky for the surgical photography and Dr. G. L. Waxler for the photomicrography is gratefully acknowledged. In addition, the author wishes to thank Mrs. G. M. Bronson for retrieval of case histories, Miss D. L. Middleton for preparing the radio- graphs, Mrs. M. K. Sunderlin for preparing the tissue sections, and Mrs. S. L. Volk for preparing the bacteriological samples. Sincere thanks are especially forthcoming to my wife, Carole, and daughter, Heather, without whose encouragement and perseverance this pro- ject would not have reached completion. ii TABLE OF CONTENTS Page INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 REVIEW OF LITERATURE. . . . . . . . . . . . . . . . . . . . . . . . 3 A. Etiology of Urolithiasis in Animals. . . . . . . . . . . . 3 B. Etiology of Urolithiasis in Man. . . . . . . . . . . . . . 8 C. Surgical Management of Urolithiasis in the Male Cat. . . . 11 D. Surgical Application of Pelvic Symphysiotomy . . . . . . . 16 MATERIALS AND METHODS . . . . . . . . . . . . . . . . . . . . . . . 17 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . 17 B. Surgical Procedure . . . . . . . . . . . . . . . . . . . . 17 C. Bacteriological Technique. . . . . . . . . . . . . . . . . 30 D. Radiological Technique . . . . . . . . . . . . . . . . . . 30 E. Laboratory Identification of Calculous Material. . . . . . 31 F. HistOpathological Technique. . . . . . . . . . . . . . . . 31 A. Introduction . . . . . . . . . . . . . . . . . . . . . . . 33 B. Bacteriological Studies. . . . . . . . . . . . . . . . . . 34 C. Chemical Analysis of Obstructing Material. . . . . . . . . 34 D. Radiological Studies . . . . . . . . . .'. . . . . . . . . 34 E. Histopathological Studies. . . . . . . . . . . . . . .~. . 36 DISCUSSION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 BIBLIOGRAPHY. . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 iii Figure 10 11 12 13 14 15 16 17 18 19 20 21 LIST OF FIGURES Abdominal area prepared for surgery . Exposure of median raphe. . . . . . . . Exposure of pelvic symphysis. . . . . . Positioning of osteotome for division of pelvic symphysis . . . . . Symphyseal separation . . . Isolation of membranous urethra . . . . Incision of penile urethra posterior to bulbourethral glands O O O O O O O O I O O O O O O O O Incision of penile urethra anterior to reflection of prepuce onto penis. . . . . . . . . . Amputation of penis . . . . . . . . . . Incision of membranous urethra anterior glands O I O O O O O O O O O O O O O O O Insertion of catheter . . . . . Placement of tension suture . . . . . . Completed anastomosis . . . . . . . . . to bulbourethral Insertion of 18 gauge needles through pubis . Placement of 26 gauge stainless steel wire. . Approximation of pelvic symphysis . . . Closed incision with catheter in place. Bowman probes . . . . . . . . . . . Urethrogram of dilated urethra. . 0 G Urethrogram showing marked narrowing at anastomosis site. Urethrogram showing minimal narrowing at anastomosis site . iv Page l9 19 20 20 21 21 23 23 24 24 25 25 27 27 28 28 29 .35 35 37 37 Figure 22 23 24 25 26 27 28 29 30 31 32 Urethrogram of male cat with recurrent urethral blockage. Urethrogram of normal male cat. . . . . . . Photomicrograph of isolated inflammation at anastomosis Site. 0 O O O I O O O O O I O O O O O O I O I O O O O O O Photomicrograph showing higher magnification of Figure 24 . Photomicrograph of surgical gut reaction at anastomosis Site. 0 O O O O O O O O O O O O O O O O O O O O O O Photomicrograph showing higher magnification of Figure 25 . Photomicrograph of urethra anterior to anastomosis site . Photomicrograph of urethra posterior to anastomosis site. Photomicrograph of urethral stenosis in male cat with recurrent urethral blockage . . . . . . . . . . . . . . Photomicrograph of urethral obliteration in male cat with recurrent urethral blockage. . . . . . . . . . Photomicrograph showing higher magnification of Figure 31 Page 38 39 40 40 41 41 43 43 44 INTRODUCTION Several surgical techniques have been reported for correction of recurrent urethral blockage in the male cat. These procedures have been develOped because of the sometimes unsuccessful attempts to control this condition medically resulting in severe impairment of normal urethral function. Since the pelvic urethra had been utilized to redirect the urine flow in many of these techniques, the thought of approaching this area via a pelvic symphysiotomy procedure seemed logical. The surgical exposure of the pelvic cavity utilizing a median pelvic symphysiotomy approach had been used to facilitate correction of certain conditions affecting this area in both man and animals. Because of the location of the obstructing material in the penile urethra, posterior extension of the initial surgical incision made this area readily accessible. This segment of the urethra had to be removed or bypassed for the surgical procedure to be successful. The idea was therefore conceived to utilize a median pelvic symphysi- otomy approach to the surgical area, remove the penile urethra, amputate the penis at the preputial reflection and anastomose the pelvic urethra to the prepuce. This approach would provide maximal exposure of the surgical area and a normal body opening through which urination would occur. To evaluate the effectiveness of the procedure, contrast radiography and histopathological sections would be used, as well as routine bacterio- logical sampling of the urinary tract and identification of the obstructing material. A desire to determine the feasibility of this surgical procedure stimulated the following study. LITERATURE REVIEW The medical management of urethral obstruction in the male cat has remained an unsolved problem. Since treatment with various therapeutic agents has not proved totally successful, several procedures have been advanced for the surgical correction of recurrent urethral blockage in the male cat. Etiology of Urolithiasis in Animals Voluminous investigational work has been accomplished in an attempt to discover the etiological factors of urolithiasis in animals; however, most of the research in man and animals has dealt with the study of only one etiological factor at a time. While this information has been reward- ing, it appears that the complexities of stone formation necessitate the consideration of several factors at one time. The chemical composition of uroliths varies between the different species of animals, and information regarding the obstructing sabulous material in cats is rather scarce. Carbone (1965) reported on a study of 82 cats of which 29 were suffering from urethral obstruction. He found that the obstructing material was composed of ammonium magnesium phosphate crystals. The small mucous plugs causing the obstruction in 4 cats did not contain any crystals in the urinary sediment. Brody (1955) compiled results from a study of 52 cases of canine uro— lithiasis. It was found from this study that 42 of the 52 dogs had phos- phatic calculi, either ammonium magnesium phosphate or calcium phosphate. Many of these calculi contained some fibrin, uric acid, cholesterol, 3 oxalate and carbonate. The remaining 10 dogs had calculi composed of uric acid or one of its salts, mainly ammonium urate. White _£__l, (1961) studied the chemical composition of calculi from 122 dogs in different parts of England, Scotland, and Wales, and found that 61.5% were composed mainly of phosphate, 15.5% of oxalate, 11.5% of urate, and 11.5% of cystine. Swingle (1953) analyzed the chemical composition of calculi from 63 cases of urethral obstruction in Montana range cattle, and all of these stones contained protein, suggesting the possibility of a mucoprotein com- plex. All calculi except one contained silica. Frequently associated with the protein and silica components were calcium, oxalate and occasionally magnesium, but only rarely were ammonium, carbonate, and phosphate identi- fied. In only one case was ammonium magnesium phosphate detected, and it was thought to be associated with a urinary infection. Aluminum and urate were not detected. Romanowski (1965) stated that urinary calculi in range cattle are composed mainly of silica, while in feedlot cattle and sheep they are com- posed mainly of ammonium magnesium phosphate. Nutritional factors have been incriminated as possible causes of uro- lithiasis. Since urinary calculi are composed of various materials found in food, dietary management has been one method of treating recurrent urolithiasis. Dickinson and Scott (1956) attempted unsuccessfully to produce uro- lithiasis in kittens by feeding a diet composed of 30.12 minerals by dry weight for as long as 24 weeks. Udall gtngl. (1958), working with range steers, found that by inducing dietary shifts, the amount of mucoprotein in the urine could be increased. They were able to bring about this shift by changing the diet from alfalfa hay to a fattening ration and by increasing the concentrate ratio from 4:1 to 8:1. They concluded that there was a reasonable probability that the mucoproteins appearing in the urine were the source of mucoproteins appearing in the calculous matrix. Udall (1962), studying the effects of increased dietary sodium chloride on the incidence of calculus in lambs, found that feeding 4 to 7% sodium chloride in the ration will effectively reduce stone formation. The sodium chloride was thought to decrease stone formation by increasing urine volumes and by lowering urine protein concentrations, both of which ‘were observed in this study. Udall ggngl. (1965) studied further the mechanism of action of sodium chloride and hypothesized that the inhibi- tory effect was due to the displacement of magnesium and phosphate by sodium chloride at the nucleation centers of the stone matrix, thus pre- venting the formation of urinary calculi. The role of early castration has long been suggested as a cause of urethral blockage in the male cat. Foster (1967) conducted a statistical analysis of 112 cases of feline urolithiasis. He concluded from this sur- vey that there was no significant difference in incidence of urolithiasis between castrates and entire males. A review of the case records for a normal male feline p0pulation over one year of age indicated that entire males constitute 31.7% and castrates 68.3%. 0f cats with urolithiasis, entire males constitute 28.4% and castrates 71.6%. The condition was found to be age associated, and it was also observed that castrated cats had longer survival and lower mortality rates after the onset of urolithiasis than entire males. The average age for the entire cat at first occurrence was 2.6 years, and for the castrate, 3.65 years. Meir (1960), in a limited histological study of feline urolithiasis, reported that castration did not produce a narrowing of the urethral lumen. Frank gt 31. (1961) measured the urethral diameters of 491 feedlot steers and found that no definite association existed between the presence of calculi and size of the urethral diameter. The mean urethral diameter of steers with calculi (0.279 inch) was not significantly different from the mean urethral diameter of steers without calculi (0.282 inch). Meir (1967) clinically evaluated 11 consecutive cases of lower urinary tract disease in male cats and suggested that bacterial infection was a predisposing cause of urethral blockage. Pseudomonas sp, was isolated in all 11 cases, and in 3 cases Proteus _p, was isolated with Pseudomonas sp, It was suggested that an inflammatory process develops which pro- duces epithelial damage, entrapment of triple phosphate crystals, ureth- ral stenosis and finally urethral blockage. The presence of ammonium magnesium phosphate crystals was thought to be a contributing factor rather than the primary etiological agent. Carbone (1965) studied 29 cases of urolithiasis in castrated and entire males. It was found that ammonium magnesium phosphate crystals appeared in normal feline urine in direct relation to the physiologic ele- vation of urine pH above 6.8. Since ammonium magnesium phosphate crystals made up the obstructing material, it was hypothesized that these crystals which form in normal urine constitute the primary cause of urethral ob- struction. It was further suggested that these crystals form small plugs which irritate the urethral wall causing inflammation, stenosis and even- tually urethral blockage. Crystals were observed in urine samples of cats with urolithiasis when the pH rose above 6.8, but crystals also appeared in 2/3 of those in which the pH was well below 6.8. Bacteriological studies were negative in 3 cats and positive for Proteus vulgaris in one cat. McCully and Lieberman (1961) reported the histopathology of a case of urolithiasis and suggested the urethral lesions could be due to the effect of the urinary calculi causing mechanical injury by their movement along the urethra. Loss of lining epithelium with necrosis in the lamina propria of the urethra suggested the probability of resultant induration and loss of urethral expansibility. Lumb (1955) mentioned the possible role that urinary colloids play in preventing urolithiasis. He believed that urinary colloids excreted in the urine would surround the crystalloid particles and prevent crystal- loid accumulation and the formation of stones. It was also suggested that testosterone and estrone, which enhance the synthesis and deposition of hyaluronic acid from which colloids are produced by hyaluronidase, might be lacking in castrated male cats. This deficiency would predispose these animals to urethral obstruction. The injection of hyaluronidase into rats increased colloid production but did not have any effect on calculous deposit. Vitamin A deficiency has been suggested as a factor in calculous for- mation. Swingle and Marsh (1956), working with steer calves, attempted to induce urolithiasis on a vitamin A deficient ration. These deficient rations by themselves were not sufficient to cause urolithiasis in cattle; however, the authors did not rule out the possibility of vitamin A de- ficiency acting as a contributing factor. Livingston (1965) suggested that hereditary factors were possibly involved in feline urolithiasis. Four cats from the same lineage were observed to have died or were euthanatized because of urolithiasis which failed to respond to any treatment, including surgery. Etiology of Urolithiasis in Man The etiology of urolithiasis in man remains a mystifying subject. King (1967) reviewed recent research concerning the etiology of urolithia— sis and remarked that the present information is so varied and contradic- tory that it is difficult to make general conclusions. Gershoff (1964) reported that only about 5% of the uroliths in man are vesical calculi. Crystallographic studies in humans with nephrolithia- sis indicated that 33% were pure calcium oxalate and 33% were mixtures of calcium oxalate and calcium phosphate. Three to five per cent were com- posed of uric acid and one per cent was composed of cystine and rarely zanthine. The remaining stones were composed of pure calcium phosphate and various mixtures of ammonium magnesium phosphate, calcium phosphate and calcium oxalate. Gershoff further stated that since approximately 95% of renal stones contain calcium, a relationship might exist between the formation of urinary calculi and dietary calcium levels. Henneman (1959) reported that in 9 of 207 consecutive patients with kidney stones the most likely cause was excessive milk intake. Urinary calcium in these patients was decreased by omitting milk from their diets, and they did not form further stones. He further stated that the renal stone to milk relationship was sufficient to postulate that a high milk intake was a common cause of renal stones. Vermeulen and Roberts (1963), working with rats, demonstrated that the calculogenic factor in milk could not be attributed to calcium alone, but that the lactose in milk was the additional factor accounting for the calculous production. By using a synthetic diet designed to mimic the composition of powdered milk, substitution of glucose for lactose sharply reduced both urine calcium and the occurrence of stone formation. Metrecal* was also included, since its carbohydrate is largely lactose. It, too, resulted in stone production similar to that seen with powdered milk. To further confuse the role of calcium in stone formation, Gill 35 3;, (1959) reported that adding calcium to the diet of rats prevented not only calcium phosphate stones, but also those of the ammonium magnesium phosphate variety. It was noted that acidification of the urine with ammonium chloride completely prevented stone growth and alkalinization with sodium bicarbonate increased stone growth. Since approximately 60% of renal stones contain phosphate, it is therefore conceivable that diets high in phosphorus would induce greater stone formation. Vermeulen.g£_§l, (1959) reported that the addition of sodium phytate or hexametaphosphate (Calgon) will prevent stones both of the magnesium and calcium types. The inhibitory action of these compounds was attributed to the high content of available phosphate in these sub- stances. Apparently, excess dietary phosphate interferes with intestinal absorption of calcium and magnesium. Though the phosphorus rises to very high levels in the urine, the concentration of calcium falls and the stone process is inhibited. Fleisch and Bisaz (1962) isolated an inorganic perphosphate from human urine which they determined by ig;zizg.evaluation to be a calcium inhibitor. It was suggested that because of the apparent inability of * Mead Johnson and Co., Evansville, Ind. lO pyrophOSphate to inhibit calcification, this compound might be beneficial in cases of urolithiasis. Oxalates are a common component of urinary calculi in man. Gershoff and Prien (1960) reported that most patients who form renal stones contain- ing calcium oxalate do not excrete abnormally large amounts of oxalate. Oxalic acid is poorly absorbed and there is no evidence that oxalate stones are normally caused by eating foods high in oxalic acid. Uric acid and cystine stones are related to metabolic derangements rather than to the ingestion of diets containing high levels of uric acid or purines. Another area which has received much attention is the role that urinary muc0proteins may play in the formation of stone matrix. Grant (1959) isolated 12 antigenic components, not detectable in normal serum, from normal human urine. He grouped these into 3 subdivisions: (a) those arising from the kidneys, ureters, and bladder, (b) trace components from the male genital tract, especially the prostate, and (c) trace components common to male urine, female urine and semen, which possibly originate in both sexes from the urethra. Boyce.g£_al, (1962) isolated an immunological component of urine which they termed matrix substance A. This component had been identified only in matrix substance of urinary calculi and from the non-ultrafiltrable solids of urine in patients with renal calculi. Keutel and King (1964) further studied the mucoprotein, matrix sub- stance A, and reported the presence of this substance was not limited to calculous disease, but appeared to be generally associated with renal disorders, especially urinary infections. Seneca gtugl. (1963), as cited by Keutel and King (1964), found that sera from pyelonephritic patients and patients with calculi contained ll antibodies to substances present in stone matrix and that this reactive sera seemed to be associated with specific bacteria. They suggested that intestinal absorption of gram negative endotoxins gave rise to antibodies which concentrated in the renal papillae and there encountered endotoxins released from bacteria invading the urinary tract. The resultant antigen- antibody precipitates were postulated to form an important part of the organic matrix of calculi. It was determined, however, that not all patients with urinary tract infections produce stones. They demonstrated that Escherichia coli, Aerobacter aerogenes and Klebsiella s2, were immuno— logically reactive with stone matrix, although other bacilla and cocci, including Proteus sp, and Pseudomonas sp,, gave no such reaction. Surgical Management of Urolithiasis in the Male Cat Various surgical procedures have been developed to provide relief for the male cat suffering from recurrent urethral blockage. The most common site of urethral blockage in the male cat is in the portion of the urethra which extends from the bulbourethral glands to the glans penis. Most surgical procedures have been attempts to circumvent this area of the urethra. Archibald and Cawley (1967) reported the sabu— lous material causing the blockage to rarely occupy more than the last 1/4 inch of the penile urethra. Meir (1960) observed obstructions of the lower urinary tract in the male cat to be predominantly at the end of the glans penis. Crawford (1940) described a urethrotomy procedure for relief of urethral blockage in the male cat. A longitudinal incision was used to incise the terminal inch of the penis down to the urethra. A silver probe was inserted to dislodge the obstructing material. The wound was allowed 12 to heal without suturing. No mention was made as to the number of cases treated in this manner. McCully (1955) described an antepubic urethrostomy technique for re- lief of recurrent urethral obstruction in the male cat. This procedure eliminated the necessity for urine to pass through the penile urethra. The urethra was transplanted to the skin on the ventral abdomen just anterior to the brim of the pelvis. Whitehead (1961) observed 2 problems in those animals in which the antepubic urethrostomy technique had been performed. The first was a severe ammonia dermatitis on the ventral abdo- men at the urethral orifice, and secondly the urethra developed a dorsal deviation in one patient which impeded urinary outflow. He modified the technique by placement of a permanent indwelling polyethylene catheter into the urethral orifice. It was observed that several patients lost the indwelling catheters 6 to 10 months postoperatively. Beamer (1959) advocated ureterocolostomy for relief of urethral blockage in the male cat. Because of the small diameter of the ureter, difficulty was encountered in keeping the ureteral lumen patent both at time of transposition and after anchorage in the wall of the colon. Poly- ethylene tubing inserted at the anastomosis site seemed to cause additional trauma. Since the ureterocolostomy procedure proved unsuccessful, further work was continued utilizing a urethrocolostomy technique. In this pro- cedure, the neck of the urinary bladder was transected just anterior to the prostate gland and anastomosed to the colon. The anastomosing site was supported with polyethylene tubing which was sutured in place at the anus for 7 days postOperatively. This procedure was used on 4 cats, 3 of which made uncomplicated recoveries. One cat died of peritonitis. In 13 this surgical experiment an attempt was also made to transplant into the colon a small segment of the wall of the urinary bladder in conjunction with the distal end of the ureters. The lumen of the ureters became occluded and the cat expired. Whittick and Bonar (1961) utilized the urethrocolostomy technique reported by Beamer on 4 cases. Three of the surgical patients made uneventful recoveries and one died postOperatively. This animal was considered a poor surgical risk. Howard (1959) reported a variation of the urethrocolostomy technique in which the fundus of the bladder was anastomosed to the ileum. A rub- ber urinary catheter extending from the bladder to the anus.was used to support the anastomosing site. No complications were observed in this animal 4 months postOperatively. Gale (1962) reported successful use of Howard's urethrocolstomy technique on 3 of 5 cases with urethral obstruc- tion. It was suspected that one death was due to peritonitis from fecal or urinary contamination. Baines and Bone (1963) described the urethro- colostomy as primarily a salvage procedure, but preferable to bringing the urethra out through the abdominal wall. Carbone (1963) reported the use of a perineal urethrostomy for relief of urethral obstruction in the male cat. In this procedure the urethra was transected just anterior to the bulbourethral glands which were removed. The membranous urethra was then sutured to a skin Opening in the perineal area. Successful use of this technique was described in 5 cats with chronic urethral obstruction and in 2 normal cats. The only postoperative compli- cations seemed to be transient dysuria and hematuria. Carbone (1965) re- ported further on 20 clinical cases utilizing the perineal urethrostomy technique. The original procedure was modified by amputating the penis 14 to prevent recannulation of the penile urethra. Immediate postoperative results indicated that 5 made uncomplicated recoveries, 8 had minor com- plications and 7 had major complications. The complications consisted of persistent cystitis or urethritis, persistent crystalluria, surgical gut reaction, stricture and recannulation of the penile urethra. Evaluation of the original 20 cases at time intervals from 6 months to 2 years revealed that 2 cats had recurrence of cystitis, one cat had recurrence of mild urethritis, one cat develOped a urinary fistula, one cat was euthanatized, and contact was lost with 2 cats. The remaining 13 cats made complete recoveries. Carbone (1967) further modified the perineal urethrostomy technique and successfully used this procedure on 26 of 28 male cats with urethral obstruction. One cat died of infectious anemia and one was euthanatized because of recurrent obstruction. This modification consisted of altering the location of the skin incision in the perineal region which facilitated the surgical procedure and shortened the operating time. Christensen (1964) reported a modification of the perineal urethros- tomy. This procedure utilized the same approach in the perineal region, but the prepuce was preserved and anastomosed to the membranous urethra. It was believed that this change would reduce the chances of dermatitis and urethral stricture. The procedure was successful on 22 of 24 male cats. Failures were attributed to uremia in one case and a urethral fistula in another case. Four to six months postsurgically, 6 clinical and 3 experimental cats had develOped no urethral blockage. Manziano and Manziano (1966) described a further modification of the perineal urethrostomy procedure which was used on 13 cases. A catheter was used as a guide during the entire operation. This change reportedly 15 eliminated the necessity for magnification devices and reduced operating time more than 50%. Manziano and Manziano (1967) described the use of a stainless steel and synthetic prosthesis, originally developed for the permanent cannula— tion of certain organs, to relieve urethral blockage in the male cat. The prosthesis was inserted into the bladder through a ventral midline abdominal incision and secured to the abdominal wall. In the event of an attack of urethral blockage a threaded rod in the prosthesis could be Opened and the bladder drained. This device was installed in 5 cats with urethral blockage and all were reported to have excellent bladder control and were leading normal lives. Fishler (1967) utilized a procedure for irrigation of the bladder to prevent recurrence of urethral obstruction in the male cat. This technique consisted of performing a cystotomy, scraping the bladder mucosa with a gall bladder scoop to remove trapped calculi and flushing the bladder with cooled Ringers solution. The bladder flush was essential to help cause contraction of the bladder and control hemorrhage. A 15% recurrence could be expected following this procedure; however, an 80% recurrence could be expected when the cystotomy was not performed and the technique was limited to removing the urethral calculi and treating symptomatically. Blake (1968) advocated the use of a perineal urethrostomy which con- sisted of bisecting the penis longitudinally and suturing the bisected cavernous tissue to the adjacent skin in the perineal region. Twenty-two cats were subjected to this procedure and 5 required further postsurgical care for urethral complications. The most common problems encOuntered ‘were skin stricture, transient hematuria and phosphocrystalluria. One cat died 2 days postsurgically with a urethral obstruction and 2 cats ex- pired from problems unrelated to urinary obstruction. 16 Surgical Application of Pelvic Symphysiotomy Freak (1962) reported the use of a pelvic symphysiotomy to approach a lacerated rectum in a cat. The pelvic symphysis was divided with a scalpel blade and separation of approximately one inch was obtained. The floor of the pelvis was closed with a single stainless steel wire suture through a drilled hole on each side of the symphysis. The cat was returned 4 months later with complaints of occasional pain when handled. The stain— less steel wire was removed and no further discomfort was reported. Ward (1967) utilized a pelvic symphysiotomy approach to increase the pelvic diameter of a cat suffering from multiple fractures of the pelvis. Holder and Peltier (1966) described the use of a pelvic symphysiotomy to approach tumors in the pelvic cavity of man. The use of wire sutures, a Parham band through the obturator foramen and Steinman pins were men- tioned as methods for approximating the pelvic symphysis. Knecht and Schiller (1966) reported prostate removal was facilitated by incising the pelvic symphysis. The pelvic symphyseal separation was reduced and fixed with 2 simple interrupted stainless steel sutures placed through predrilled holes in the pubis and through the obturator foramen. The technique provided better exposure of prostatic vessels for ligation and better exposure of the urethra and bladder in effecting an anastomosis. MATERIALS AND METHODS A. Introduction Fifteen healthy entire male cats, approximately one year of age, were obtained from a local animal supplier for use in this experiment. In ad- dition, the surgical procedure was performed on 20 clinical cases of recur— rent urethral blockage admitted to the Michigan State University Veteri- nary Clinics. B. Surgical Procedure Basal anesthesia was achieved in the clinical patients with 4% thia- mylal sodium* given intravenously to effect. These animals were then intubated and surgical anesthesia was maintained with a mixture of methoxy— flurane** and oxygen, utilizing a closed system anesthetic machine.*** The experimental animals were anesthetized with 6% pentobarbital sodium+ given intravenously to effect. All animals were premedicated with atropine sulfate++ (1/120 gr./m1.) given subcutaneously at a dosage of 0.02 mg./lb. of body weight. *Surital, Parke, Davis and Co., Detroit, Mich. **Metafane, Pitman and Moore Co., Indianapolis, Ind. ***Ohio Heidbrink, Model 960, Madison, Wisc. 1'Halatal, Jensen-Salsbery Labs, Kansas City, Mo. ++AtrOpine sulfate, North American Pharmacal, Dearborn, Mich. l7 18 The ventral abdomen was clipped from the umbilicus to the scrotum (Fig. 1) and scrubbed with a liquid antiseptic solution.* After surgical preparation, the animals were positioned in dorsal recumbency with the forelegs secured to the side and the hind legs secured over the back of the surgical table. A midline pelvic symphysiotomy approach was used to expose the surgical area. The skin incision extended on the ventral mid— line from just anterior to the pubis to the penile sheath. The subcutaneous tissues were incised to expose the median raphe of the gracillus and ad— ductor longus muscles (Fig. 2). The median raphe consists of fibrous tissue much like the linea alba. Care was exercised to avoid the external pudendal vessels and spermatic cord which occupy a position on either side of the midline. The ventral pelvic muscles were incised on the mid— line down to the pelvic symphysis (Fig. 3), and this incision was carried forward approximately one—half inch to Open the abdominal cavity. Blunt dissection was extended posteriorly to expose the penile urethra. The pelvic symphysis was separated with an osteotome, working anterior to posterior (Figs. 4 and 5), and fragments of the internal obturator muscle still attached to the midline were cut with scissors. The symphyseal separation was widened by placing a curved hemostat in the pelvic cavity and Opening the jaws laterally. The membranous urethra was isolated and lifted through the symphyseal separation by placing a curved hemostat under the urethra (Fig. 6). The urethra was isolated as far posteriorly as possible. The bulbourethral glands prevent elevation of the membranous urethra at the pelvic outlet. By exerting upward force on the curved *Betadine Surgical Scrub, The Purdue Frederick Co., Yonkers, N.Y. 19 Fig. l. Abdominal area prepared for surgery. Fig. 2. Exposure of median raphe by reflection of sub- cutaneous tissue. 20 Fig. 3. Exposure of pelvic symphysis by reflection of pelvic muscles. Fig. 4. Positioning of osteotome for division of pel— vic symphysis. 21 Fig. 5. Symphyseal separation obtained by pressure from hemostat. Fig. 6. Isolation of membranous urethra. 22 hemostat, urine flow was inhibited and prevented from contaminating the surgical field. Three incisions were used to transect the urethra and one to ampu- tate the penis. The first incision was made through the penile urethra adjacent and posterior to the bulbourethral glands (Fig. 7). The second incision was made in the penile urethra adjacent and anterior to the reflection of the prepuce onto the penis (Fig. 8). This reflection was visualized as a bulbous enlargement on the urethra. The penile urethra was bluntly dissected free and discarded. The penis was next grasped with a hemostat and extended posteriorly to reveal the exact location of the preputial reflection onto the penis (Fig. 9). The penis was then ampu- tated at this reflection. This step achieved maximal preservation of preputial tissue. The fourth incision was made through the membranous urethra adjacent and anterior to the bulbourethral glands (Fig. 10). The bulbourethral glands and associated urethra remained in place. A grooved director was inserted through the external preputial orifice which turned the prepuce inward, and a 6 French radiographic catheter* was inserted through the preputial orifice to the bladder (Fig. 11). The preputial mucosa was identified. Maximal expansibility of the prepuce and membran- ous urethra was attained by blunt dissecting around these structures. The prepuce and membranous urethra were anastomosed with 000 medium chromic surgical gut with attached curved needle** in all cases except one, in which 000 surgical silk** was used. A closely placed simple interrupted *Radiographic Catheter, American CytoscOpe Makers, Inc., Pelham Manor, N. Y. **Ethicon, Inc., Somerville, N. J. Fig. 7. Incision of penile urethra posterior to bulbo- urethral glands. Fig. 8. Incision of penile urethra anterior to reflec- tion of prepuce onto penis. 24 Fig. 9. Amputation of penis at preputial reflection. Fig. 10. Incision of membranous urethra anterior to the bulbourethral glands. 25 Fig. 11. Insertion of catheter prior to anastomosis. Fig. 12. Placement of tension suture. 26 suture pattern was used to effect the anastomosis around the catheter. The suture pattern was started dorsally and continued 180 degrees to the ventral side. A tension suture was then placed across the partially com- pleted anastomosing site which allowed rotation of the urethra (Figs. 12 and 13). This procedure facilitated placement of the sutures around the remaining 180 degrees of the urethra. Prior to closure Of the pelvic symphysis, the fibrous preputial tis- sue was grasped with thumb forceps posterior to the anastomosing site and tensed in a forward direction. This procedure reduced tension on the anastomosing site. The pelvic symphysis was prepared for closure by inserting an 18 gauge l-l/2 inch needle* through each side of the pubis (Fig. 14). Twenty-six gauge stainless steel wire** was threaded through the needles. The needles were removed and the stainless steel wire tied to approximate the pelvic symphysis (Figs. 15 and 16). During the clo- sure, slight upward tension was placed on the wire, which helped to re— place the urethra into the pelvic cavity. Originally, 2 stainless steel wires, one inserted through the pubis and one around the obturator foramen, were used to close the symphyseal separation. In later cases, one metal suture proved to be sufficient. The gracillus and adductor longus muscle fascia, subcutaneous tissue and skin were closed by layers utilizing simple interrupted nylon*** sutures (Fig. 17). The catheter was secured to the perineal area with one simple interrupted nylon suture and removed on the *Becton, Dickinson and Co., Rutherford, N. J. **Steri-spool, Thomas W. Halliday, Los Angeles, Calif. ***Tasalon, Coats and Clark, New York, N. Y. 27 Fig. 13. Completed anastomosis. Fig. 14. Insertion of 18 gauge needles through pubis. 28 Fig. 15. Placement of 26 gauge stainless steel wire. Fig. 16. Approximation of pelvic symphysis. 29 — -. ‘-.—n‘ Fig. 17. Incision closed with catheter in place. 30 fourth postsurgical day. The rear legs were placed in hobbles for 2 days following surgery to minimize stress on the symphyseal area. All entire male animals were castrated at the completion of the surgery. C. Bacteriological Technique Ten of the experimental cats and 11 of the clinical cases had samples taken for bacteriological studies at the time of surgery. A urine sample and bladder mucosal swab were taken through a cystotomy incision. These samples were plated on tryptose base agar enriched with 7% bovine blood and on MacConkey's agar.* In addition, brain—heart semisolid infusion tubes* enriched with 0.15% agar were used to detect the presence of anaerobic bacteria. The blood agar plates were observed for a period of 5 days, the MacConkey plates for 2 days, and the semisolid tubes for 2 weeks. A swab of the bladder and urethral mucosa was taken on all experimental cats at the time of necropsy. D. Radiological Technique At the completion of the experiment, voiding urethrograms were per- formed on the experimental cats, one normal cat and one male with re- current urethral blockage. The animals were anesthetized with 6%‘pento- barbital sodium** given to effect. A metal catheter was used to empty the bladder of urine and 20 ml. Of 20% sodium iodide*** were infused into the bladder. A radiograph was taken of the urethral area simultaneous to manual compression of the bladder. *Difco Scientific Labs, Detroit, Mich. **Halatal, Jensen-Salsbery Labs, Kansas City, Mo. ***Sodium Iodide, Jensen-Salsbery Labs, Kansas City, MO. 31 E. Laboratory Identification of Calculous Material The calculous material was analyzed for chemical content in 6 of the 20 clinical cases. The analysis was conducted in accordance with the methods described by Hepler (1962). F. Histopathological Technique At time intervals varying from 52 to 191 days postsurgically, the experimental animals were euthanatized with pentobarbital sodium* and a necropsy performed. In order to properly evaluate the effects of this surgical procedure on the urinary system, sections for histopathological examination were taken from the kidneys, ureters, bladder, urethra and anastomosing site. Division of the anastomosing site into 3 areas, one incorporating the site, one anterior and one posterior, provided represen- tative tissues from the entire area of anastomosis. Four random sections were taken from each of the above areas for microsCOpic examination. Clo- sure of the urethral lumen from tissue shrinkage was prevented at the anastomosis site by placing a 0.050 inch diameter polyethylene catheter into the urethra. All tissues were fixed in Zenker's solution, washed in running tap water for 24 hours, trimmed and placed in 70% alcohol. The polyethylene catheter was withdrawn prior to placing the urethral tissues in 70% alcohol. *9: The tissues were processed in an Autotechnicon, embedded in Paraplast*** *Toxital, Jensen-Salsbery Labs, Kansas City, Mo. **Technicon Co., Chauncey, N. Y. ***Aloe Scientific Division of Brunswick, St. Louis, Mo. 32 and sections were cut at 6 microns. The slides were stained with hema- toxylin and eosin as described in the Manual of Histologic and Special Staining_Techniques of the Armed Forces Institute of Pathology, Washington, D.C. (1957). The tissues were examined by light microsc0py. RESULTS A. Introduction 1. Experimental Cases. Thirteen of the original 15 male cats were alive at the completion of the experiment. Both of the cats which expired developed complications at the anastomosis site. One cat develOped a stricture and the other a retroperitoneal abscess from apparent leakage of urine. 2. Clinical Cases. Fifteen of the original 20 cases are alive at the present time. Five animals, which were considered poor surgical risks at the time of surgery, expired 6, 7, 10, 12, and 14 days postsurgically. These animals had suffered previous attacks of urethral blockage and at the time of admittance were showing signs of depression and bladder dis- tention. Three of the animals expired as a result of urine leakage at the anastomosis site. Patency of the anastomosed urethra was established at the time of necropsy in the remaining 2 cats. NecrOpsy findings revealed a mild cystitis in one and the isolation of Pseudomonas aeruginosa from the lungs and small intestine of the other. The longest postsurgical observation time for the clinical cases has been 11 months. Two of the remaining 15 clinical cases appeared to be developing strictures as evidenced by dysuria postsurgically. The urethras were 33 34 successfully dilated utilizing Bowman probes* (Fig. 18). Two cats developed a transient hematuria 2 and 6 months postsurgically which responded to antibacterial therapy. B. Bacteriological Studies 1. Experimental Cases. 0f the 10 cases subjected to bacteriological studies, only one case was positive for bacterial growth at the time of surgery. In this case a Clostridium‘_p, resembling Clostridium fallax was isolated. At the time of necropsy, bacteriological swabs were taken from the urethral mucosa and bladder. Both hemolytic and nonhemolytic Escherichia coli were isolated in 2 cases, pure isolates of nonhemolytic Escherichia coli in 3 cases and pure isolates of hemolytic Escherichia coli in 3 cases. An Enterobacter _p, was isolated in one case. NO bac- terial growth was evidenced in 5 cases. 2. Clinical Cases. Eleven clinical cases had bacteriological samples taken at the time of surgery. Ten of these cases were negative for bac- terial growth. A nonhemolytic Micrococcus _p, was isolated in one case. C. Chemical Analysis of Obstructing Material The calculous material present in the urethra and bladder was analyzed in 6 of the 20 clinical cases. All of these were positive for calcium, ammonium and magnesium phosphates. No other chemical components were detected. D. Radiological Studies Voiding urethrograms were taken of all the experimental animals, *Arista Surgical Supply, New York, N. Y. 35 Fig. 18. Bowman probes, used to dilate urethral lumen. xl/2. Fig. 19. Experimental cat with urethral dilatation (A). 36 one normal male cat and one male cat with urethral blockage. Two of the urethrograms illustrated gross dilatation of the pelvic urethra as depicted in Figure 19. The remaining 11 cases showed various degrees of urethral narrowing, which varied from marked narrowing in Figure 20 to only minimal narrowing (Fig. 21). The cat with recurrent urethral blockage (Fig. 22) demonstrated marked narrowing of the urethra when compared to the normal male cat (Fig. 23). E. HistOpathological Studies The primary histOpathological change observed in the experimental cats was the presence of an inflammatory reaction at the anastomosis site. These changes were characterized by isolated areas of lymphocytic infil- tration and fibrous connective tissue proliferation. This varied from a mild response as shown in Figures 24 and 25 to a more marked response (Figs. 26 and 27). The granulomatous reaction in Figures 26 and 27 was associated with the presence of surgical gut which was thought to be the primary inciting agent. Pathological changes were not Observed in the experimental cats from the histological sections taken anterior to the anastomosis site (Fig. 28), or posterior to the anastomosis site (Fig. 29). The inversion of the pre— puce did not produce any evidence of contact dermatitis from urine, as might be expected. The sections in which a catheter was used to prevent closure of the urethra during fixation demonstrated the presence of kera— tinous debris in the preputial lumen (Fig. 29); however, test sections made not utilizing the catheter did not show evidence of this material. It was concluded that catheter withdrawal caused dislodgement of this keratinous debris. 37 Fig. 20. Experimental cat showing marked narrowing at the anastomosis site (A). Fig. 21. Experimental cat with minimal narrowing at anastomosis site (A). 38 Fig. 22. Male cat with recurrent urethral blockage. Notice extreme narrowing of urethra (A). Fig. 23. Normal male cat. Notice absence of urethral narrowing (A). Fig. 25. Higher magnifica- tion of Fig. 24. Note area of lymphocytic infiltration around nerve (A) and connective tissue proliferation (B). Hematoxylin and eosin. x 100. 39 Fig. 24. Photomicrograph of anastomosis site in experi- mental cat. Note areas of lympho- cytic infiltration (A), edema (B), muscle degeneration (C), and isolated areas of undefined necrosis (D). Hematoxylin and eosin. x 40. yak; .-\ Fig. 27. Higher magnifi- cation of Fig. 26. Note area of granulomatous reaction around surgical gut (A). Hematoxylin and eosin. x 100. 40 aflOA‘ . P: Fig. 26. Photomicrograph of anastomosis site in experi- mental cat. Note presence of 3V suture granuloma. Hematoxylin J and eosin. x 40. Fig. 29. Photomicrograph of inverted normal prepuce pos- terior to anastomosis site. Hematoxylin and eosin. x 40. 41 Fig. 28. Photomicrograph of urethra anterior to anasto- mosis site. Note absence of inflammatory response. Hema- toxylin and eosin. x 40. 42 MicroscOpic examination of tissues from the kidneys, ureters, bladder and urethra did not demonstrate any significant histopathological changes associated with this surgical procedure. Histopathological sections taken from the penile urethra of a male cat with urethral obstruction demonstrated a marked inflammatory reaction with resultant urethral stenosis (Fig. 30). Figures 31 and 32, taken from the same animal, show the complete obliteration of the urethral lumen. ‘t