A technique for perineal urethrostomy in the cat

A technique for perineal urethrostomy in the cat is described and the results of its successful use in fifteen consecutive cases reported. The pelvic urethra is sutured to skin to produce first intention healing.     

Modified perineal urethrostomy using preputial mucosa in cats

A modified perineal urethrostomy was performed in 14 males cats with partial or complete urethral obstruction. Follow-up information was available for 2 to 18 months. By use of this method, the preputial tissues were preserved, and the penile urethra was anastomosed to the preputial mucosa to enlarge and lengthen the urethra. Urine flow was reestablished in all cats without evidence of urethral stenosis or other major complications. Appearance of the perineal region and prepuce was not substantially altered.     

Retrospective study of indications for and outcome of perineal urethrostomy in cats

OBJECTIVES: To evaluate indications for and outcome of perineal urethrostomy in cats. METHODS: The medical records of 59 cats that had undergone perineal urethrostomy were evaluated. Short-term follow up information (for a period of four weeks following surgery) was available for all of the cats. Long-term follow up information (for a period of at least four months) was available for 39 cats. RESULTS: Early complications occurred in 25.4 per cent of cats and late complications were observed in 28.2 per cent of cats. The most frequent late complication was recurring bacterial urinary tract Infection. CLINICAL SIGNIFICANCE: Despite frequent complications and recurring signs of lower urinary tract disease, 32.2 per cent of the cats had a disease-free long-term outcome (mean four years, median 3.9 years), and 88.6 per cent of clients interviewed thought that their cats had a good quality of life after surgery.     

Surgical revision of the urethral stoma following perineal urethrostomy in 11 cats: (1998-2004)

Eleven cats required urethral stoma revision because of urethral stricture following perineal urethrostomy. At surgery, eight cats had evidence of inadequate dissection to the bulbourethral glands, and three cats had evidence of urine extravasation into the subcutaneous tissues. Following revision of the stoma, long-term follow-up was obtained in nine cases. For eight cats, owners reported no complications after the revision. Failure to dissect beyond the bulbourethral glands and inadequate mucosa-to-skin apposition resulted in postoperative stricture formation. Stoma revisions were performed a median of 71 days following the initial perineal urethrostomy, indicating that long-term evaluation of cases is necessary.     

Management of incontinence following pre-pubic urethrostomy in a cat using an artificial urethral sphincter

A 14-year-old male neutered domestic shorthair cat presented with a 4-year history of urinary incontinence following prepubic urethrostomy. Physical examination confirmed peristomal dermatitis, urine scalding and constant urine leakage. Haematology, serum biochemistry and urinalysis were unremarkable. Ultrasonography revealed a non-distended urinary bladder. An artificial urethral sphincter mechanism, with subsequent incremental inflation of the cuff 6 weeks later, resulted in complete resolution of clinical signs, return to normal urinary function and excellent quality of life. The cat was still continent at 5-year follow-up. Further studies including additional cases are required to highlight effectiveness and harms of the procedure.     

Prevalence of bacterial urinary tract infection after perineal urethrostomy in cats.

It has been reported that the prevalence of bacterial urinary tract infection (UTI) increases after perineal urethrostomy in male cats. Perineal urethrostomy, using a surgical technique preserving striated urethral sphincter function, was performed on 2 groups of cats. The first group consisted of healthy castrated cats. The second group of cats had recurrent or persistent urethral obstruction. All cats had normal urethral sphincter function after surgery, as measured by urethral pressure profilometry and electromyography. Long-term periodic urinalysis and bacterial culturing of urine was performed on all cats. Twenty-two percent of the previously obstructed cats had recurrent bacterial UTI, compared with none of the healthy cats. On the basis of these findings, we suggest that perineal urethrostomy per se does not predispose cats to bacterial UTI, but surgical alteration of the urethral meatus combined with an underlying uropathy may increase the prevalence of ascending bacterial UTI after surgery.     

Evaluation of trends in frequency of urethrostomy for treatment of urethral obstruction in cats

OBJECTIVE: To determine hospital proportional morbidity rates (HPMR) for urethral obstructions, urethral plugs or urethroliths, and urethrostomies in cats in veterinary teaching hospitals (VTH) in Canada and the United States between 1980 and 1999. DESIGN: Epidemiologic study. ANIMALS: 305,672 cats evaluated at VTH. PROCEDURES: Yearly HPMR were determined for cats with urethral obstructions, urethral plugs or urethroliths, or urethrostomies from data compiled by the Purdue Veterinary Medical Database. The test for a linear trend in proportions was used. RESULTS: Urethral obstructions were reported in 4,683 cats. Yearly HPMR for urethral obstructions declined from 19 cases/1,000 feline evaluations in 1980 to 7 cases/1,000 feline evaluations in 1999. Urethral plugs or urethroliths affected 1,460 cats. Yearly HPMR for urethral plugs or urethroliths decreased from 10 cases/1,000 feline evaluations in 1980 to 2 cases/1,000 feline evaluations in 1999. A total of 2,359 urethrostomies were performed. Yearly HPMR for urethrostomies decreased from 13 cases/1,000 feline evaluations in 1980 to 4 cases/1,000 feline evaluations in 1999. CONCLUSIONS AND CLINICAL RELEVANCE: Frequency of feline urethrostomies performed at VTH in Canada and the United States declined during the past 20 years and paralleled a similar decline in frequency of urethral obstructions and urethral plugs or urethroliths. These trends coincide with widespread use of diets to minimize struvite crystalluria in cats, which is important because struvite has consistently been the predominant mineral in feline urethral plugs during this period.     

Buccal mucosal graft urethroplasty for reversal of a perineal urethrostomy in a goat wether

OBJECTIVE: To describe the use of buccal mucosa as a urethral graft for reversal of perineal urethrostomy (PU) in a castrated male goat. STUDY DESIGN: Clinical case report. SAMPLE POPULATION: One client-owned castrated male goat. RESULTS: An 8-month-old Pygmy cross wether was admitted for urolithiasis and PU stricture. After repeated unsuccessful attempts at urethrostomy reversal and urethral reconstruction, a buccal mucosal graft was used for urethroplasty. Buccal mucosa proved to be an excellent graft for urethral repair. Normal urination has occurred through the reconstructed region for at least 24 months. CONCLUSIONS: Buccal mucosa worked well as a graft for urethroplasty and PU reversal. CLINICAL RELEVANCE: Grafting with buccal mucosa may also prove useful in other urethral repair techniques in small ruminants.     

Preservation of cadavers for surgical technique training

OBJECTIVE: To evaluate a technique for preservation of organoleptic tissue characteristics (color, odor, texture, and flexibility) in cadavers used for surgical instruction. STUDY DESIGN: Experimental study. ANIMALS: Forty-three canine cadavers. METHODS: Cadavers were preserved with a modified Larssen solution of the Hospital Cochim, Paris and cryopreservation. Tissue handling qualities were evaluated in surgical laboratory sessions. RESULTS: All cadavers kept texture and tissues consistency, especially skin and muscle, similar to those of live animals. Some skin desquamation and pallor of the mucous membranes occurred with repetitive freeze-thaw cycles. CONCLUSIONS: This preservation technique provides acceptable cadaver quality and tissue handling for use in surgical instruction. CLINICAL RELEVANCE: Preparation of patient cadavers by intravascular injection of modified Larssen solution yielded suitable instructional models for surgical training.     

Use of fine-wire electrodes for electromyographic evaluation of the external urethral sphincter during urethral pressure profilometry in male cats

Evaluation of urethral pressure profilometry (UPP) with simultaneous fine-wire electromyography of the external urethral sphincter (EUS) was conducted in 11 healthy adult male cats sedated with xylazine and ketamine. A 3.5-F urethral catheter with a closed end and two 1-mm side-ports was infused with sterile 0.9% NaCl solution at a rate of 2 to 3 ml/min. A fine-wire electromyographic (EMG) electrode was placed percutaneously into or near the external urethral sphincter prior to the onset of the UPP. The maximal urethral pressure achieved and functional profile length were recorded from UPP. Setting both catheter withdrawal rate and paper speed at 5 mm/s enabled the measurement of actual urethral length directly from UPP. Sphincter EMG activity was rated as slight (+), moderate (+ +), or intense (+ + +). All recordings were replicated once during each trial for 8 cats and trials were replicated 5 to 7 days later in 4 cats. Before catheterization, EMG activity of the external urethral sphincter was rated slight (+), whereas intense (+ + +) activity accompanied insertion. The activity evoked by movement of the catheter subsided, but intense EMG activity of the external urethral sphincter was recorded from onset to completion of catheter withdrawal in all cats in both trials. The mean maximal urethral pressure was 93.1 +/- 13.29 cm H2O. The mean function urethral length was 8.1 +/- 0.93 cm. Maximal urethral pressure or function profile length did not differ significantly between recordings within trials or between trials. Simultaneous recording of EMG activity and UPP of the external urethral sphincter was shown to be a simple, noninvasive technique for assessing neuromuscular and anatomic urethral function.     

Vulvovaginectomy and perineal urethrostomy for neoplasms of the vulva and vagina

Vulvovaginectomy and perineal urethrostomy were performed in three dogs with extensive neoplasms of the vulva and vagina. One benign tumor (fibroleiomyoma) and two malignant tumors (transitional cell carcinoma and anaplastic spindle cell sarcoma) were diagnosed. Survival times were 9 weeks to 10 months. Urinary continence was preserved in all three dogs. The procedure may be curative for benign tumors or malignant tumors that have not yet metastasized; it is a palliative procedure for advanced malignancies.     

Electromyographic evaluation of the external urethral sphincter during cystometry in male cats

Electromyographic (EMG) evaluation of the external urethral sphincter (EUS) was conducted during cystometry in 11 adult male cats sedated with xylazine and ketamine. A percutaneously placed antepubic catheter was used for bladder infusion and recording intravesicular pressures during cystometrography (CMG). A fine-wire electrode was placed percutaneously into or near the EUS for recording EMG during CMG. The bladder was infused with sterile 0.9% NaCl solution at a rate of 2 to 3 ml/min until a detrusor reflex was initiated. Intravesicular pressures at the onset of infusion, immediately prior to micturition, at the onset of urine flow, and at the maximal voiding pressure were recorded. The time from infusion to micturition, from opening pressure to return to baseline, and from the beginning to the end of the CMG were also recorded. The total volume of 0.9% NaCl solution infused and the residual bladder volume after micturition were also measured. Recordings were replicated once during each trial in all cats, and trials were replicated once approximately 1 week later in 4 cats. Micturition patterns were characterized by slight to moderate EUS EMG activity during vesicular filling, with reduction in activity during emptying. Maximal EMG activity was recorded at the completion of the reflex and was associated with pulsatile expulsion of small amounts of urine. The simultaneous recording of CMG and EUS EMG with fine-wire electrodes was simple and reliable for assessing the neuromuscular integrity and synchrony of detrusor and EUS muscles. There were no significant differences in variables between recordings within trial 1, but there were differences (P less than or equal to 0.05) between trials for pressure at the onset of urine flow and maximal voiding pressure.     

Static hydraulic urethral sphincter for treatment of urethral sphincter mechanism incompetence in 11 dogs

Objective : To review the postoperative results and complications associated with urethral sphincter mechanism incompetence managed with a static hydraulic urethral sphincter. Methods : Case records and a telephone owner questionnaire were retrospectively used to assess postoperative urinary continence scores (1 – dripping constantly to 10 – completely dry) and presence and frequency of complications. Results : Eleven spayed females were included. Median continence score/10 (range) awarded preoperatively was 3 (2 to 6), and scores at two weeks, three and six months were 8 (4 to 10), 9 (4 to 10) and 8 (4 to 10), respectively. At the last survey, the median continence score of 9 (5 to 10) was significantly better (P=0·004) than before surgery. Complete continence was achieved in 36·4% of dogs. The median (range) follow‐up time was 412 (118 to 749) days. Complications occurred in 9 of 11 dogs and included dysuria (n=7), bacterial cystitis (n=7), longer urination time (n=8), urinary retention (n=3), haematuria (n=1), pain (n=3) and incisional seroma (n=3). Clinical Significance : Static hydraulic urethral sphincter was frequently associated with minor complications but no major complications (i.e. those requiring further surgery). Continence scores were significantly improved compared with those before surgery, with the possibility of further improvement following inflation of the sphincter.     

Catheter-induced urethral trauma in cats with urethral obstruction

Fifteen cats were evaluated with urethral obstruction. Penile trauma by catheterization was the major indication for perineal urethrostomy. Ten cats had developed a urethral stricture and five had rupture of the urethra following medical management. All cats had abnormalities in penis and/or prepuce and/or scrotal sacs including hyperemia or swelling. Perineal urethrostomy was performed in all cases and they were evaluated for 6 months after surgery. Few complications were noted. Urinary tract infection was the most frequent complication observed. The clients considered their cats to have a good quality of life following surgery.