Long term use of hydraulic artificial urethral sphincters in nine dogs from New Zealand with urethral sphincter mechanism incompetence.

AIMS: To report on the long-term outcomes of hydraulic artificial urethral sphincter (HAUS) placement for the correction of urethral sphincter mechanism incompetence (USMI) in New Zealand dogs. METHODS: Retrospective data were obtained from cases of dogs which had a HAUS placed after failed medical and/or surgical management of USMI between August 2012 and November 2016. Owner assessment of urinary incontinence was evaluated by an online survey in May 2017 using a visual analogue scale (0 being normal, 100 being severely affected) for the frequency, volume and severity of any straining to urinate, immediately prior to the placement of the HAUS and at the time of the survey. The number of days between surgery and the completion of survey were recorded. RESULTS: Seven females and two male dogs, which were all desexed except for one female, were eligible for inclusion in the study. The period of follow-up following HAUS placement ranged from 206-1,685 days. Following HAUS placement, frequency and volume of urinary incontinence decreased for six dogs and were practically unchanged for three dogs. The median frequency score decreased from 70 to 13 and the volume score decreased from 73 to 12. There was no consistent change in the perceived degree of straining to urinate. Complications occurred in three dogs; one required repositioning of a dislodged injection port, one required management for haematuria and a hypoplastic bladder, and one required surgical removal of fibrous tissue around the HAUS cuff. CONCLUSIONS AND CLINICAL RELEVENCE: HAUS placement was an effective method for the treatment of persistent USMI in most dogs and provided good clinical results based on owner assessment. The technique was associated with few complications and allowed successful long-term control of urinary incontinence without the need for medical management.

Laparoscopic placement and urodynamic effects of an artificial urethral sphincter in cadaveric dogs.

OBJECTIVE: To describe a laparoscopic approach for placement of a percutaneously controlled artificial urethral sphincter (AUS) in female cadaver dogs and compare the change in urethral pressure and lumen diameter after filling the device. STUDY DESIGN: Experimental study. ANIMALS: Canine female cadavers (n = 10). METHODS: A laparoscopic technique was used to implant the AUS in 10 cadaver dogs. Maximum urethral closure pressure (MUCP), cystourethral leak point pressure (CLPP), and urethral luminal area were measured at 0, 25, 50, and 75% cuff inflation. Necropsy was performed after urethral pressure profilometry and cystoscopy data collection to assess for trauma caused by the procedure. RESULTS: Laparoscopic implantation was performed successfully in all 10 cadavers with no evidence of inadvertent trauma. Median MUCP at 0% AUS fill (48.9 cmH2 O) was significantly lower than 75% fill (243.5 cmH2 O). Median CLPP at 0% fill (5.0 cmH2 O) was significantly lower than 75% fill (23.2 cmH2 O). Significant differences were also found comparing urodynamic values 25 to 50%, 25 to 75%, and 50 to 75%. Cystoscopic evaluation revealed progressive decreases in urethral lumen area and significant differences between the urethral luminal area values as the AUS cuff was inflated. CONCLUSION: Laparoscopic placement of an AUS can be performed successfully in cadaver dogs, improved urethral pressure profile parameters, and visibly occluded the urethral lumen. Further studies of laparoscopic placement in clinical cases affected by urethral sphincter mechanism incompetence are warranted.

Placement of an artificial urethral sphincter in 8 male dogs with urethral diverticulum.

BACKGROUND: Urethral diverticulum (UD) is a poorly defined anomaly consisting of an outpouching of the urethra. Management without surgical resection is not previously reported in dogs. HYPOTHESIS/OBJECTIVES: Report the outcome of male dogs presented for urinary incontinence with UD treated with an artificial urethral sphincter (AUS). ANIMALS: Eight client-owned dogs with UD treated with an AUS. METHODS: Multicenter retrospective study. Medical records from male dogs with urinary incontinence were reviewed. INCLUSION CRITERIA:  diagnosis of a UD by retrograde cystourethrography, cystoscopy, abdominal ultrasonography or contrast computed tomodensitometry (CT) or a combination of these modalities, AUS placement, and at least 1 follow-up. Urinary continence score (UCS) was attributed retrospectively. RESULTS: Median UCS at presentation was 1/5. A contrast cystourethrogram was diagnostic in 8/8 dogs. All diverticula were saccular, and 7/8 were within the prostatic urethra and 1/8 extended up to the membranous urethra. A congenital origin was suspected in 7 dogs and acquired in 1. Concurrent anomalies included renal dysplasia or chronic pyelonephritis (n = 4), bilateral cryptorchidism (n = 3), and pelvic urinary bladder (n = 3). All dogs were poorly/moderately responsive to phenylpropanolamine. Artificial urethral sphincter placement resulted in improvement in continence in all dogs with a median UCS of 4/5 (5/5 in 2/8 dogs, 4/5 in 5/8 dogs, 3/5 in 1/8 dogs). CONCLUSION: Urethral diverticulum should be considered in male dogs with persistent urinary incontinence not responding to medical management. Artificial urethral sphincter placement is an effective therapeutic option that improved continence scores in all dogs.

Evaluation of percutaneously adjustable hydraulic urethral sphincters with and without induced mechanical failure.

OBJECTIVE: To describe (1) the radiographic appearance of intact hydraulic urethral sphincters (HUS) and (2) the success of leak detection using clinically feasible methods. STUDY DESIGN: Prospective, blinded in vitro study. SAMPLE POPULATION: Thirty HUS devices (10 each of 8, 10, and 12 mm diameter sizes). MATERIALS AND METHODS: All devices were inflated with saline (0.9% NaCl) solution to complete occlusion, inspected, and weighed over a 24-hour period for manufacturing defects. HUS phantoms were created to mimic surrounding soft tissues. One randomly selected HUS of each size was evaluated radiographically at different inflation volumes and angles. All HUS systems were then evaluated in random order before and after puncture with volumetry, manometry, radiography, and contrast fluoroscopy. Volumetry was the total volume (mL) retrieved from each HUS system. Manometry was the pressure (cm H2 O) within each HUS system. The HUS devices were filled to a known volume before each measurement. RESULTS: When all HUS sizes were considered, volumetry did not reveal significant differences before and after puncture, but manometry was significantly different (P < .001). Radiography was 63.8% sensitive and 88.3% specific for puncture diagnosis, with inter-observer agreement of 0.58. Contrast fluoroscopy was 78.4% sensitive and 100% specific, with inter-observer agreement of 0.97. CONCLUSIONS: Of those methods tested, contrast fluoroscopy was the most sensitive, specific, and consistent method of leak detection. Manometry was also helpful, but may be difficult to use clinically. Volumetry and radiography were relatively poor indicators of leakage in this model.

Use of a percutaneously controlled urethral hydraulic occluder for treatment of refractory urinary incontinence in 18 female dogs.

OBJECTIVE: To evaluate the efficacy and safety of a percutaneously controlled urethral hydraulic occluder (HO) device for the treatment of refractory urinary incontinence (RUI) in female dogs with various urogenital anomalies. STUDY DESIGN: Case series. ANIMALS: Female dogs with RUI (n = 18). METHODS: Retrospective evaluation of dogs after a silicone ring (HO) was surgically placed around the proximal urethra. The ring was connected to a subcutaneous injection port with actuating tubing. Residual incontinence was treated with percutaneous infusion of sterile saline into the device to provide extraluminal urethral compression. Dogs were assessed for continence (owner-assessed 10-point continence scale) and complications at standard time points. RESULTS: All 18 dogs had significantly improved continence scores (P < .001) after HO placement (median and mean score pre-HO = 2.8 and 3.3; post-HO = 10 and 8.9, respectively) with a median follow-up time of 32 months. "Functional" continence (score ≥ 9) was achieved in 67% of dogs after HO placement, though only 13/18 clients were compliant with inflations. Of dogs belonging to compliant owners, 12 (92%) had a functional continence score. Six dogs (33%) did not require inflation to achieve continence. Urethral obstruction occurred as a complication in 3 dogs. CONCLUSIONS: Use of an HO device was an effective long-term treatment for RUI when traditional options failed. The technique was associated with some complications, and these risks should be considered before use.

Outcome after placement of an artificial urethral sphincter in 27 dogs.

OBJECTIVE: To evaluate the safety and efficacy of an adjustable artificial urethral sphincter (AUS) in a population of dogs with acquired or congenital urinary incontinence. STUDY DESIGN: Case series. ANIMALS: Dogs (n = 27) with naturally occurring urinary incontinence. METHODS: Medical records (January 2009-July 2011) of dogs that had AUS implantation for treatment of urinary incontinence were reviewed and owners were interviewed by telephone to assess outcome. Continence was scored using a previously established analogue scale, with 1 representing constant leakage and 10 representing complete continence. RESULTS: Twenty-four female and 3 male dogs had AUS implantation. Causes of incontinence included urethral sphincter mechanism incompetence (n = 18), continued incontinence after ectopic ureter repair (6), and pelvic bladder (3). Medical therapy was unsuccessful in 25 dogs before AUS implantation. Surgery was performed without major complications in 25 dogs; 2 developed partial urethral obstruction after 5 and 9 months. Median (interquartile range) follow-up for the other 25 dogs was 12.5 (6-19) months. Continence scores were significantly improved (P < .0001) between the preoperative period (2 [1-4]) and last follow-up (9 [8-10]). Overall, 22 owners described themselves as very satisfied, 2 as satisfied, and 3 as unsatisfied. CONCLUSIONS: AUS implantation was successful in restoring continence in male and female dogs with both congenital and acquired urinary incontinence. Dogs that develop partial urethral obstruction may require AUS removal.

Artificial urethral sphincter in male dogs with urethral sphincter mechanism incompetence: 19 cases (2010-2017).

OBJECTIVE: To assess the outcome and safety of surgically placed artificial urethral sphincters in male dogs with urethral sphincter mechanism incompetence. MATERIALS AND METHODS: We included dogs with urethral sphincter mechanism incompetence treated by placing an artificial urethral sphincter from January 1, 2010 to December 31, 2017. The continence score (scale 1 to 5, with 5 indicating complete continence) was evaluated before and after implantation. Follow-up information was obtained from the institution's medical records (short-term up to 12 months) and questionnaires were completed by telephone (long-term ≥12 months) for evaluation. RESULTS: Medical therapy was unsuccessful in 18 dogs and unknown in one dog before the artificial urethral sphincter placement. Short-term continence improved in 16 of the 19 (84%) dogs. Four patients were lost to follow-up. Nine of 15 (60%) dogs showed long-term continence improvement, eight of 15 (53%) remained completely continent. The median follow-up was 1785 (range 2 to 3234) days. The complication rate was 56% (9/16). Minor complications, including haematoma, stranguria/temporary dyssynergia and mild inflammation at the port, were reported in four of 16 (25%) dogs. Five of 16 (31%) experienced major complications, including stranguria/mechanical urethral obstruction, persistent dyssynergia, fistula at the port and port rotation. CLINICAL SIGNIFICANCE: Artificial urethral sphincter placement is a valid option for treating incontinent male dogs that show an insufficient response or become refractory to medical or other prior surgical management. A high-complication rate is associated with this procedure.

Diagnosis, management, and outcome of urethral obstruction secondary to the capsule associated with the artificial urethral sphincter device.

BACKGROUND: Urethral obstruction secondary to artificial urethral sphincter (AUS) implantation is a recognized complication in dogs. However, urethral obstruction secondary to AUS-associated capsule formation has been described rarely. HYPOTHESIS: Describe clinical and diagnostic findings, management, and outcome in 6 dogs with urethral obstruction secondary to AUS-associated capsule formation. ANIMALS: Six client-owned dogs. METHODS: Retrospective study. Medical records between January 1, 2010, and June 30, 2021, were reviewed to identify dogs with urethral obstruction associated with the AUS device. RESULTS: The AUS device was implanted a median of 884 days (range, 20-2457 days) before presentation for urethral obstruction. Median age at time of urethral obstruction was 4.7 years (range, 3.1-8.7 years). Clinical signs at the time of urethral obstruction were stranguria (n = 4), pollakiuria (3), weak urine stream (2), and worsened urinary incontinence (1). In all dogs, the urethra was noted to be stenotic during urethroscopy and positive contrast cystourethrography. All dogs underwent surgery, and a fibrous capsule associated with the AUS was found to be causing urethral stenosis. Resolution of urethral obstruction occurred in all dogs after transection or removal of the capsule. Positive bacterial cultures were obtained from the capsule, AUS, or both in all dogs. Recurrence of urethral obstruction had not occurred in any dog at the time of follow-up. CONCLUSIONS AND CLINICAL IMPORTANCE: Urethral obstruction secondary to capsule formation is an uncommon but clinically important complication associated with use of the AUS. Continued investigation is needed to evaluate this complication more thoroughly, and its possible association with infection.

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.

Long-Term Outcome of Female Dogs Treated with Static Hydraulic Urethral Sphincter for Urethral Sphincter Mechanism Incompetence.

The purpose of the study was to report the postoperative outcome, complications, and long-term follow-up of the use of a static hydraulic urethral sphincter for the management of urethral sphincter mechanism incompetence in female dogs. Medical records were reviewed to extract information on long-term (>365 days) outcome data. Telephone owner questionnaire was performed to assess postoperative urinary continence scores (scale 1-10, where 10 is complete continence) and the presence and frequency of complications. Twenty female dogs were included. Mean (±standard deviation) time to follow-up was 1,205.1 (±627.4) days. Median continence score/10 (range) was 3.5 (2-6) preoperatively, and 9.0 (7-10) at the last follow-up. Median continence score was significantly higher at all time points postoperatively compared with before surgery (P < .001). Complete continence was achieved in 90% of bitches. Minor complications occurred in 13 bitches and included dysuria (8), bacterial cystitis (8), longer urination time (10), incisional seroma (5), urinary retention (3), hematuria (2), and pain when urinating (2). Major complications occurred in one dog (static hydraulic urethral sphincter removed 28 mo after placement). Continence scores were sustainably improved in the long-term. Complications were mostly minor. Urinary tract infections were the most common but resolved with conventional antibiotic treatment.

Urodynamic effects of a percutaneously controlled static hydraulic urethral sphincter in canine cadavers.

OBJECTIVE: To describe a percutaneously controlled static hydraulic urethral sphincter (SHUS) and evaluate urodynamic effects of the SHUS in canine cadavers. SAMPLE POPULATION: Cadavers of 6 adult female dogs. PROCEDURE: Cadavers were obtained immediately after dogs were euthanatized. Baseline maximal urethral closure pressure (MUCP) and cystourethral leak point pressure (CLPP) were measured by use of a urethral pressure profilometer. An SHUS system was constructed by use of a silicone vascular occluder and subcutaneous infusion port. The SHUS system was then placed around the pelvic urethra in each cadaver. Measurements of MUCP and CLPP were repeated after varying occlusion of the SHUS (0%, 25%, and 50% occlusion). Baseline MUCP and CLPP values were compared with values obtained at 0%, 25%, and 50% occlusion of the SHUS by use of repeated-measures ANOVA. RESULTS: Mean +/- SD MUCP for canine cadavers was 7 +/- 1.3 cm H2O at baseline, which increased to 127 +/- 53 cm H2O after 50% occlusion of the SHUS. Mean CLPP was 11 +/- 8.6 cm H2O at baseline, which increased to 73 +/- 38 cm H2O after 50% occlusion of the SHUS. Mean MUCP and CLPP were significantly associated with the amount of occlusion. CONCLUSIONS AND CLINICAL RELEVANCE: The SHUS had positive effects on MUCP and CLPP in canine cadavers. Therefore, additional evaluation of the SHUS in live dogs is warranted.

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.

Retrospective evaluation of urethral bovine cross-linked collagen implantation for treatment of urinary incontinence in female dogs.

BACKGROUND: Transurethral collagen injections are an alternative treatment for canine urinary incontinence. There is controversy regarding the long-term effectiveness of collagen and the impact urethral coaptation and injection site have on outcome. HYPOTHESIS/OBJECTIVES: To evaluate outcome and client satisfaction after urethral collagen injections, and correlation between degree of urethral coaptation and collagen placement with outcome. ANIMALS: Thirty-six procedures on 31 dogs, 10 with ureteral ectopia. METHODS: Retrospective review of records and video evaluation of injection procedures. Follow-up communication with owners was performed between 1 and 56 months after bovine cross-linked collagen implantation to evaluate duration of continence, need for additional medical therapy, and owner satisfaction. Continence score was evaluated before and after the procedure, and after additional medical therapy, if needed. Injection location and degree of urethral coaptation was assessed with respect to duration of continence. RESULTS: Dogs had a significant increase in continence score after the procedure. Mean (SD) duration of continence in dogs without addition of medication was 16.4 (15.2) months, and 5.2 (4.3) months in dogs needing additional medical therapy. No significant difference was found with respect to degree of coaptation. Median client satisfaction with the procedure was 100%. CONCLUSIONS AND CLINICAL IMPORTANCE: Transurethral collagen implantation may be a viable option for treatment of female dogs with urethral sphincter mechanism incompetence, particularly after medical failure. Duration and degree of improvement are variable. Client satisfaction was excellent despite lack of complete continence in some dogs, and highlights the importance of discussing outcome expectations with owners.