Cystourethropexy to correct refractory urinary incontinence due to urethral sphincter mechanism incompetence. Preliminary results in ten bitches

Long-term outcome of the transobturator vaginal tape inside out for the treatment of urethral sphincter mechanism incompetence in female dogs

OBJECTIVE

To evaluate the long-term efficacy of the transobturator vaginal tape inside out (TVT-O) in female dogs with urethral sphincter mechanism incompetence (USMI).

STUDY DESIGN

Retrospective study.

ANIMALS

Incontinent spayed female dogs (n = 12).

METHODS

TVT-O tape was inserted in 12 incontinent bitches diagnosed with USMI. Follow-up information was evaluated by a telephone questionnaire, and a continence score was attributed.

RESULTS

One year after surgery, 7 of 12 (58%) dogs were completely continent. Two dogs were removed from the long-term analysis (1 dead and 1 lost). At a median follow-up time of 85 months (range, 28-95), 4 of 10 dogs were completely continent without medical treatment. Incontinence recurred in 6 dogs at a median time of 2 months after surgery (range 1-20). Among these 6 dogs, 4 regained continence, and 2 had sporadic episodes of incontinence with additional medical treatment. No postoperative complications were encountered.

CONCLUSION

TVT-O alone was successful in maintaining long-term continence in 40% of the dogs. Additional postoperative medical treatment was effective in restoring continence in another 40% of the dogs.

CLINICAL SIGNIFICANCE

TVT-O provides an alternative treatment of USMI in female dogs that is safe and less invasive than standard surgical techniques.

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.

Urethral Sphincter Mechanism Incompetence in Dogs: An Update

Urethral sphincter mechanism incompetence (USMI) is the most common cause of acquired urinary incontinence in dogs. The pathogenesis of USMI is multifactorial and complex. Studies have shown variable results regarding the effects and timing of sterilization on the incidence of USMI. Diagnosis of USMI is often based on history, physical examination, and elimination of other differentials. Treatment options for USMI include medications, such as α-adrenergic agents and estrogen products, minimally-invasive urethral bulking procedures, surgical procedures (e.g., indwelling urethral occluders), or combination therapy. The overall prognosis for USMI is typically fair to good with long-term therapy.

The outcome of combined urethropexy and colposuspension for management of bitches with urinary incontinence associated with urethral sphincter mechanism incompetence

OBJECTIVE

To report 1) a combined technique of urethropexy and colposuspension; 2) intra- and postoperative complications; and 3) medium term outcome.

STUDY DESIGN

Retrospective case series.

ANIMALS

Female dogs (n = 30) with urinary incontinence associated with urethral sphincter mechanism incompetence (USMI) unresponsive to medical management.

METHODS

Through a ventral median celiotomy, the bladder was positioned abdominally to permit the urethra to be anchored with single interrupted polypropylene sutures to the prepubic tendon and linea alba. The vagina was freed from the vesicovaginal and rectovaginal attachments and advanced cranially by traction before attachment to the prepubic tendon with polypropylene mattress sutures. Bitches were re-examined 2 weeks postoperatively; medium term outcome (>6 months) was evaluated by telephone interview of owners.

RESULTS

At a median follow up of 39.5 months, 21 bitches (70%) were considered to have an "excellent" medium term outcome with complete resolution of their urinary signs; 8 (26.6%) had a "good" outcome, and 3 (10%) had mild transient dysuria postoperatively.

CONCLUSION

Combined urethropexy and colposuspension resulted in complete resolution of urinary incontinence in 70% of bitches with USMI and was not associated with major complications.

Subtotal vaginectomy for management of extensive vaginal disease in 11 dogs

OBJECTIVE

To report (1) a surgical technique for subtotal vaginectomy using a combined abdominal and vestibular approach; (2) intra- and postoperative complications; and (3) long-term outcome.

STUDY DESIGN

Retrospective case series.

ANIMALS

Female dogs (n = 11) with extensive intramural vaginal disease.

METHODS

Through a ventral median celiotomy, the cranial aspect of the vagina was freed and ovariohysterectomy (OVH) was performed in intact females. After episiotomy, the vaginal wall was incised at the vestibulovaginal junction cranial to the urethral orifice, and the vagina freed from any remaining pelvic attachments. Dogs were reexamined at 4 weeks and 6 months. Long-term outcome was evaluated by contacting the primary veterinarian by phone.

RESULTS

Five dogs had benign vaginal disease and 6 had malignant vaginal neoplasia. A combined abdominal and vestibular approach permitted subtotal vaginectomy in all dogs; 6 dogs also had OVH. No major complications occurred and clinical signs had resolved by 4 weeks. One dog with malignant neoplasia was euthanatized 3 months later for metastatic disease and 1 dog developed postoperative urinary incontinence. Local recurrence or metastases were not identified in the other dogs.

CONCLUSION

Combined abdominal and vestibular approach for subtotal vaginectomy allowed complete resection of extensive vaginal lesions, was not associated with major complications, and outcome was favorable.

Laparoscopic procedures in dogs and cats

Laparoscopic procedures are gaining wider application in veterinary medicine. The following article contains description of indispensable equipment for performing surgical procedures with use of laparoscopic technique and reviews some laparoscopic procedures which found application in veterinary medicine.

Acquired urinary incontinence in the bitch: update and perspectives from human medicine. Part 3: The urethral component and surgical treatment

Urethral sphincter mechanism incompetence (USMI) is the most common cause of urinary incontinence in dogs. Surgery may be recommended if the animal does not respond to medical treatment or becomes refractory. In this third part of a three-part review, surgical options for the treatment of USMI are described. Colposuspension is the most frequently described procedure and offers a fair prognosis, with about 50% of the dogs being continent after surgery and most of the reminder being improved or more responsive to medical treatment. Urethropexy offers a similar success rate, but with a higher rate of complications. Endoscopic injection of collagen is an attractive technique due to its minimally invasive nature and low risk of adverse effects. Initial results may however deteriorate with time. Other procedures have been reported, but involve a low number of cases and have resulted in variable success rates. In women, stress urinary incontinence is mainly treated by minimally invasive procedures involving vaginal placement of sub-urethral slings.

Transobturator vaginal tape inside out for treatment of urethral sphincter mechanism incompetence in female dogs: cadaveric study and preliminary study in continent female dogs

OBJECTIVES

(1) To describe a surgical technique adapted from the "transobturator vaginal tape inside-out" (TVT-O) used in women and to define the trajectory of the tape on canine cadavers, and (2) to determine the urodynamic and morphological effects of the TVT-O in continent bitches.

STUDY DESIGN

Cadaveric and experimental in vivo study.

ANIMALS

Fresh female canine cadavers (n=12) and spayed female Beagle dogs (2).

METHODS

(1) TVT-O was inserted in 12 cadavers. Dissection was performed and distances between the tape and neighboring structures were recorded. (2) TVT-O was inserted in 2 continent female Beagle dogs. Urethral pressure profilometry and vaginourethrograms were performed preoperatively, immediately after surgery, and 2, 4, and 6 months postoperatively. Histopathology was performed 6 months after surgery.

RESULTS

(1) TVT-O tape was consistently located in a perineal space before entering the obturator foramina and was located at a safe distance from major neurovascular structures including the femoral vessels and obturator nerve. (2) TVT-O was performed without any surgical or postoperative complications in 2 continent bitches. Histopathologic examination of the tissues surrounding the tape revealed a mild fibroblastic proliferation with a mild to minimal lymphoplasmacytic inflammatory infiltration.

CONCLUSIONS

TVT-O is a feasible and accurate procedure that can be performed in continent bitches with a low risk of complications.

Transobturator vaginal tape inside out for treatment of urethral sphincter mechanism incompetence: preliminary results in 7 female dogs

OBJECTIVES

To evaluate the clinical efficacy of the transobturator vaginal tape inside-out (TVT-O) in incontinent female dogs affected with urethral sphincter mechanism incompetence (USMI) and to determine its urodynamic and morphologic effects.

STUDY DESIGN

Case series.

ANIMALS

Incontinent spayed female dogs (n=7).

METHODS

TVT-O tape was inserted in 7 incontinent female dogs diagnosed with USMI. Urethral pressure profilometry (UPP) and vaginourethrograms were performed preoperatively, and 1 and 3 months postoperatively. Clinical efficacy of the technique was evaluated and complications reported. Follow-up information was evaluated by a telephone questionnaire.

RESULTS

All dogs were continent immediately after the procedure. Incontinence recurred 2 months after surgery in 1 dog and was treated by phenylpropanolamine administration. At mean follow-up time of 11.3 months, 6 of 7 dogs were continent. An iatrogenic urethral tear occurred intraoperatively in 1 dog. No postoperative complications were encountered. The postoperative UPPs showed significantly increased maximal urethral closure pressure and integrated pressure. Postoperative vaginourethrograms were unremarkable. The surgical procedure did not modify the location of the urinary bladder neck in dogs with a "pelvic urinary bladder" preoperatively.

CONCLUSIONS

TVT-O was efficient in maintaining short term continence in 6 of 7 dogs affected with USMI.

Surgical management of urinary incontinence

Urethral sphincter mechanism incompetence and ureteral ectopia are the two most common causes of urinary incontinence in dogs and cats. Surgical treatments for both disorders have been described. Once a diagnosis is made, surgical intervention may lead to improved outcomes with resolution of incontinence in many patients. Proper case selection and surgical technique are critical in achieving clinical success when managing these difficult cases.

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.

Laparoscopic-assisted cystopexy in dogs

OBJECTIVE

To develop a laparoscopic-assisted technique for cystopexy in dogs.

ANIMALS

8 healthy male dogs, 7 healthy female dogs, and 3 client-owned dogs with retroflexion of the urinary bladder secondary to perineal herniation.

PROCEDURES

Dogs were anesthetized, and positive pressure ventilation was provided. In the healthy male dogs, the serosal surface of the bladder was sutured to the abdominal wall. In the healthy female dogs, the serosa and muscular layer of the bladder were incised and sutured to the aponeurosis of the external and internal abdominal oblique muscles. Dogs were monitored daily for 30 days after surgery.

RESULTS

All dogs recovered rapidly after surgery and voided normally. In the female dogs, results of urodynamic (leak point pressure and urethral pressure profilometry) and contrast radiographic studies performed 30 days after surgery were similar to results obtained before surgery. Cystopexy was successful in all 3 client-owned dogs, but 1 of these dogs was subsequently euthanatized because of leakage from a colopexy performed at the same time as the cystopexy.

CONCLUSIONS AND CLINICAL RELEVANCE

The laparoscopic-assisted cystopexy technique was quick, easy to perform, and not associated with urinary tract infection or abnormalities of urination.

Urethropexy for the management of urethral sphincter mechanism incompetence in the bitch

Urethropexy was performed on 100 bitches for the management of urethral sphincter mechanism incompetence (SMI). The dogs ranged in age from 12 months to nine years (mean 4.5 years). Diagnosis of the condition was based upon clinical, laboratory and contrast radiographic examinations, and clinical response to medical management. In all bitches, incontinence developed in the adult individual and in the majority (89 bitches) after spaying. Radiographic findings were unremarkable in 22 bitches, apart from the presence of an intrapelvic bladder neck. Follow-up periods ranged from 12 months to seven years (mean 2.9 years). Fifty-six bitches were completely cured by surgery, 27 became less incontinent and 17 either failed to respond (nine animals) or showed an initial improvement in urinary function, but then relapsed (eight animals). Nine of these 17 animals underwent a second urethropexy procedure, resulting in a cure in six and an improvement in three cases (follow-up 12 to 41 months, mean 22.2 months). A deterioration in the response rate was observed over time. Postoperative complications were seen in 21 bitches and included an increased frequency of micturition (14 bitches), dysuria (six bitches) and anuria (three bitches).

Detrusor myopathy in young beagle dogs

Hematoxylin and eosin-stained sections of urinary bladder were examined microscopically from 449 male and female beagle dogs after 2- to 4-week toxicology studies. Degenerative lesions (detrusor myopathy) of the urinary bladder muscular tunic were present in 59 of 449 (13%) dogs. Myopathic lesions consisted of focal to multifocal areas of smooth muscle fiber atrophy with cytoplasmic basophilia and vacuolation, individual cell necrosis, enlarged smooth muscle nuclei and nucleoli, and occasional mitotic figures. Adjacent areas of arteritis and periarteritis were present in 10 of 59 (17%) beagles with detrusor myopathy suggesting a possible ischemic pathogenesis of the smooth muscle lesions. There was no significant difference in prevalence of myopathy in beagles administered vehicle or various test compounds. Prior urinary catheterization procedures appeared to augment the prevalence of myopathy; some lesions were adjacent to minor, iatrogenically traumatized urinary bladder mucosa. Muscle lesions were not observed in urinary bladders from mongrel dogs, monkeys, cats, rats, or microswine. When compared to crossbred dogs and other laboratory species, the beagle dog thus appears to be sensitive to development of detrusor myopathy.

Diagnosis and surgical management of ectopic ureters

Ureteral ectopia is a congenital abnormality of the terminal segment of one or both ureters in which the ureteral orifice is located distal to the trigone of the bladder. Continuous or intermittent urinary incontinence is the most frequently reported clinical symptom associated with ureteral ectopia. A variety of anatomic morphologies of ectopic ureters have been reported. Historically, surgical therapy focused on reestablishing drainage of the ureters into the bladder lumen. However, continued urinary incontinence after surgery is the most frequently reported complication. Specific classification and successful management of the various types of ectopic ureters remain diagnostic and therapeutic challenges to the veterinary clinician. Cystoscopic evaluation of the lower urinary tract and urodynamic evaluation of bladder and urethral function has improved the presurgical assessment of the patient. Surgical procedures, which are aimed at repositioning the ureteral orifice(s) within the bladder lumen and treating primary sphincter incompetence, are necessary to successfully manage small animal patients with ectopic ureters.

Evaluation of a transpelvic sling procedure with and without colposuspension for treatment of female dogs with refractory urethral sphincter mechanism incompetence

OBJECTIVE

To evaluate a sling procedure using a polyester ribbon passed through the obturator foramen, around the urethra, and fixed outside the pelvis for the treatment of female dogs with refractory urethral sphincter mechanism incompetence (USMI).

ANIMALS

26 female dogs with USMI that had not improved with medical management.

METHODS

All dogs underwent a transpelvic sling procedure, and in 13, with a radiographic diagnosis of a pelvic bladder, additional colposuspension was performed. Multichannel urethral pressure profilometry (UPP) and diuresis cystourethrometry (UCM) were performed in all dogs before and in seven dogs 2 to 14 months after surgery. Long-term results of surgery and medical therapy were determined.

RESULTS

13 dogs (50%), 6 of these without additional colposuspension, were continent after surgery and remained continent during a follow-up period of 12 to 36 months (mean, 19 months). Seven, three of which had colposuspension, had improved markedly. Four of these dogs became continent with additional medical therapy. Five dogs did not improve, and three of these were eventually euthanatized. In one dog, the sling was removed after 5 days because of persistent stranguria. Surgery and medical therapy together resulted in continence in 17 dogs (65%) during a follow-up period of 6 to 36 months (mean, 22 months). Postoperative dysuria or stranguria occurred in six dogs, and four of these underwent a colposuspension procedure. Two dogs developed a fistula, 2 and 3 years after surgery. Preoperatively, decreased urethral resistance was suggested by the findings of UPP and UCM in 25 dogs, and an abnormally high compliance was found in 3, detrusor instability in 2, and a low threshold pressure in 1 dog. There was no apparent correlation between these findings and the outcome of surgery. Urethral closure pressures measured after surgery were significantly increased but were still lower than the normal range in all dogs with persistent or recurrent incontinence.

CONCLUSIONS

A transpelvic sling procedure, with or without additional colposuspension, can be useful in the management of dogs with refractory urinary incontinence. The procedure is not beneficial if it does not increase urethral pressure close to, or within, the normal range.

Surgical treatment of male dogs with urinary incontinence due to urethral sphincter mechanism incompetence

A modified technique for fixation of the deferent ducts to the abdominal wall as a therapy for urinary incontinence caused by urethral sphincter mechanism incompetence (USMI) in male dogs is described, and the results in seven dogs are reported. The goal of this treatment was to achieve an effect similar to colposuspension in female dogs with USMI. An increase in urethral length of an average of 28 mm was obtained (range, 5 to 50 mm, measured radiographically). Preoperatively, the neck of the bladder was located intrapelvically in five of seven dogs. Postoperatively, the neck of the bladder was located intra-abdominally, near the caudo-ventral abdominal wall, in all dogs. After a follow-up period of 12 to 49 months, the response to surgery, based on lack of or decrease of incontinence, was excellent in three dogs, good in another three, and poor in one dog.

Developments in the understanding of the pathophysiology of urethral sphincter mechanism in competence in the bitch

Developments in understanding the pathophysiology of urinary incontinence caused by urethral sphincter mechanism incompetence (SMI) are reviewed. SMI is a multifactorial condition; affected bitches have shorter urethras, reduced urethral tone and more caudally positioned bladder necks than continent bitches. Other factors thought to be important in the aetiology of SMI include neutering, breed, body size, docking and obesity. Most of the recent developments in the understanding of SMI have resulted from radiographic and urodynamic investigations of normal and affected bitches. The urodynamic technique of urethral pressure profilometry is discussed and its contribution as an investigative tool reviewed.