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.     

Use of a particulate extracellular matrix bioscaffold for treatment of acquired urinary incontinence in dogs

OBJECTIVE: To evaluate use of a particulate bioscaffold consisting of the extracellular matrix (ECM) of the urinary bladder from pigs for treatment of acquired urinary incontinence in dogs resistant to medical treatment. DESIGN: Case series. ANIMALS: 9 female dogs with acquired urinary incontinence. PROCEDURE: In 6 dogs, 30 mg of particulate ECM in 1.0 mL of a carrier consisting of glycerin and saline 10.9% NaCI) solution was injected into each of 3 equally spaced sites around the circumference of the internal urethral sphincter via an endoscopic technique. In the remaining 3 dogs (control dogs), 1.0 mL of the carrier alone was injected in 3 equally spaced sites around the circumference of the internal urethral sphincter in a similar manner. RESULTS: For dogs treated with the ECM, median duration of urinary continence following treatment was 168 days (range, 84 to 616 days), whereas for the control dogs, median duration of urinary continence following the procedure was 14 days (range, 7 to 31 days). Two of the 3 control dogs were treated with the ECM at the end of the study and were continent for 119 and 252 days. No adverse effects were observed in any dog. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that endoscopically guided injection of particulate ECM into the internal urethral sphincter may be useful for the treatment of acquired urinary incontinence in female dogs.     

Clinical response and urethral pressure profile changes after phenylpropanolamine in dogs with primary sphincter incompetence

Based on clinical response, urethral pressure profile changes, and lack of side effects, phenylpropanolamine was effective and safe in treating dogs with primary sphincter incompetence. Primary sphincter incompetence was diagnosed in 11 female and 8 male dogs with urinary incontinence. Urodynamics of the dogs were assessed, using a combined urethral pressure profile and urethral sphincter electromyography. Male and female dogs had significantly (P less than 0.05) lower maximal urethral closure pressures, when compared with clinically normally dogs (36.91 +/- 8.20 cm of H2O vs 79.72 +/- 4.61 cm of H2O for female dogs and 48.63 +/- 8.68 cm of H2O vs 99.77 +/- 11.71 cm of H2O for male dogs). After treatment with phenylpropanolamine, there was a significant increase in maximal urethral closure pressure in both sexes to within normal range (77.73 +/- 8.70 cm of H2O in females and 92.50 +/- 14.60 cm of H2O in males). Electromyographic activity was normal before and after treatment. Urinary incontinence resolved clinically in all but 1 male and 1 female dog; however, the condition in these 2 dogs improved considerably. Minimal side effects were seen clinically. Mean arterial blood pressure was not altered by treatment. Plasma estrogen and testosterone concentrations in 8 female dogs were not different from those in continent female dogs. The incontinence in these dogs was considered a sphincter incompetence rather than estrogen responsive.     

Evaluation of a selective neurectomy model for low urethral pressure incontinence in female dogs

OBJECTIVE: To develop a model of low urethral pressure incontinence and compare the relative contributions of the pudendal and hypogastric nerves with urethral function by performing selective neurectomy and ovariohysterectomy in dogs. ANIMALS: 19 healthy Foxhounds. PROCEDURE: Dogs were allocated into 2 groups. The first group (10 dogs) underwent bilateral hypogastric neurectomy and ovariohysterectomy and subsequent bilateral pudendal neurectomy. The second group (9 dogs) underwent bilateral pudendal neurectomy and subsequent hypogastric neurectomy and ovariohysterectomy. Urethral pressure profilometry and leak point pressure (LPP) tests were performed before and after each neurectomy. RESULTS: Before surgery, mean +/- SD LPP and maximal urethral closure pressure (MUCP) in all dogs were 169.3 +/- 24.9 cm H2O and 108.3 +/- 19.3 cm H2O, respectively; these values decreased to 92.3 +/- 27 cm H2O and 60.7 +/- 20.0 cm H2O, respectively, after both selective neurectomy surgeries. There was a progressive decline of LPP after each neurectomy; however, MUCP decreased only after pudendal neurectomy. Fifteen dogs had mild clinical signs of urinary incontinence. All dogs appeared to have normal bladder function as indicated by posturing to void and consciously voiding a full stream of urine. Urinary tract infection did not develop in any dog. CONCLUSIONS AND CLINICAL RELEVANCE: Hypogastric and pudendal neurectomy and ovariohysterectomy caused a maximum decrease in LPP whereas pudendal neurectomy caused a maximum decrease in MUCP. IMPACT ON HUMAN MEDICINE: This model may be useful for evaluation of treatments for improving urinary control in postmenopausal women.     

Treatment of urinary incontinence in dogs by endoscopic injection of Teflon

Twenty-two dogs with urethral sphincter incompetence, nonresponsive to phenylpropanolamine administration, were treated by urethral submucosal injection of Teflon. Urinary continence was achieved in all dogs for at least 2 months. Urinary incontinence recurred in 14 dogs (64%) and was controlled by a second Teflon injection in 11 of 12 dogs (92%). Minor complications included transient stranguria, with or without hematuria, after 4 of 35 injection procedures. One dog had temporary partial urethral obstruction after treatment.     

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.     

Treatment of urinary incontinence in bitches by endoscopic injection of glutaraldehyde cross-linked collagen

Thirty-two spayed bitches with urinary incontinence due to urethral sphincter incompetence, non-responsive to phenylpropanolamine administration, were treated by urethral submucosal injection of glutaraldehyde cross-linked collagen. Urinary incontinence resolved after a single injection in 19 of the bitches. Additional medication with phenylpropanolamine was necessary in five of these dogs, however. Of the 13 bitches that remained incontinent, the injections were repeated in nine. This resulted in a return to continence in five dogs, although two of these required additional medication for complete continence. The cure rate due to collagen injections alone is 53 per cent (17 of the 32 cases). A total of 41 injections were performed and no postoperative complications were observed.     

Evaluation of colposuspension for treatment of incontinence in spayed female dogs

OBJECTIVE: To determine the long-term effects of colposuspension in spayed female dogs with urinary incontinence and identify preoperative anatomic or urodynamic measurements associated with a successful outcome. DESIGN: Prospective study. ANIMALS: 23 client-owned spayed female dogs with urinary incontinence. PROCEDURE: Prior to surgery, a history was obtained, and a physical examination, CBC, serum biochemical analyses, urinalysis, bacterial culture of a urine sample, vaginourethrocystography, urethral pressure profilometry, and leak point pressure test were performed. Colposuspension was performed, and preoperative tests were repeated 2 months after surgery. Clients were interviewed 2 weeks, 1 month, and 1 year after surgery. RESULTS: 22 dogs were followed up for 1 year. Twelve had complete urinary control 2 months after surgery, and 3 had complete urinary control 1 year after surgery. Dogs with normal urinary control at 2 months had an increased leak point pressure (LPP), compared with preoperative measurements, and their LPP was the same as normal dogs. Eight dogs had complete urinary control, and 9 were considered greatly improved 1 year after surgery when medical treatment was added to the effect of colposuspension. Client satisfaction was high, with 19 of 22 (86%) owners being pleased with their decision to have surgery performed. The only predictors of complete urinary control 2 months after surgery were a more caudal position of the external urethral opening in relation to the pubis on preoperative radiographs and a longer overall urethral length. CONCLUSIONS AND CLINICAL RELEVANCE: Colposuspension alone will result in complete urinary control in few dogs with urinary incontinence but may improve urinary control sufficiently that owners will be pleased. Preoperative vaginourethrocystography may be helpful in predicting response to surgery, and the LPP test correlates with improved urinary control.     

Evaluation of palliative stenting for management of malignant urethral obstructions in dogs

OBJECTIVE: To evaluate use of balloon-expandable and self-expanding metallic stents in management of malignant urethral obstructions in dogs. DESIGN: Original study. ANIMALS: 12 dogs with malignant urethral obstructions. PROCEDURES: The extent and location of urethral obstructions and the diameter of adjacent unaffected luminal segments were determined by use of fluoroscopically guided wires and measuring catheters. Stents were chosen to extend approximately 1 cm proximal and distal to the obstruction. Stent diameters were chosen to be approximately 10% greater than the diameter of healthy portions of the urethra to prevent displacement. Stents were placed in the urethra under fluoroscopic guidance to restore luminal patency. RESULTS: 3 dogs received balloon-expandable metallic stents, and 9 dogs received self-expanding metallic stents. The placement procedures were rapid, safe, and effective at restoring luminal patency and were not associated with major complications. Complications included recurrent urethral obstruction secondary to blood clot formation and urethral edema in 1 dog and stent dislodgement into the urinary bladder in 1 dog. All dogs were able to urinate immediately after the procedure. Nine dogs (3/4 females and 6/8 males) were continent or mildly incontinent after stent placement. Of the remaining 3 dogs, 2 developed severe incontinence and 1 had an atonic bladder. Seven dogs were considered to have good to excellent outcome, 3 had fair outcome, and 2 had poor outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Transurethral placement of metallic stents was a safe and effective palliative treatment option for dogs with malignant urethral obstructions.     

Results of cystometry and urethral pressure profilometry in dogs sedated with medetomidine or xylazine

OBJECTIVE: To compare effects of medetomidine and xylazine hydrochloride on results of cystometry and micturition reflexes in healthy dogs and results of urethral pressure profilometry (UPP) in sedated and conscious dogs. ANIMALS: 20 dogs. PROCEDURES: Urodynamic testing was performed 6 times in each dog (3 times after administration of xylazine [1 mg/kg of body weight, IV] and 3 times after administration of medetomidine (30 microg/kg, IM). Before each episode of sedation, UPP was performed. Heart and respiratory rates and indirect blood pressures were recorded prior to and 5, 10, 20, and 30 minutes after injection of sedative. Cystometry measurements included threshold volume, threshold pressure, and tonus limb. The UPP measurements included maximal urethral closure pressure (MUCP), functional profile length, and, in male dogs, plateau pressure. RESULTS: Mean MUCP was decreased markedly in xylazine- and medetomidine-sedated dogs. Xylazine and medetomidine also decreased plateau pressure in male dogs. The MUCP measurements were consistent among days for conscious and xylazine-sedated dogs but were inconsistent for medetomidine-sedated female dogs. The proportion of valid cystometry measurements was greater for xylazine (39 of 60) than for medetomidine (27 of 60). Cystometry was considered invalid when bladder pressure reached 30 cm H2O without initiation of a micturition reflex. CONCLUSIONS AND CLINICAL RELEVANCE: Medetomidine and xylazine have similar effects on measurement of UPP and cystometry. Medetomidine was less consistent among days for UPP in female dogs and produced fewer valid cystometry tests, compared with xylazine. For urodynamic evaluations, medetomidine administered IM cannot be substituted for xylazine administered IV.     

Prostatopexy as a treatment for urethral sphincter mechanism incompetence in male dogs

OBJECTIVES: The incidence of urinary incontinence due to urethral sphincter mechanism incompetence (USMI) in male dogs is relatively rare compared with the incidence in bitches, but the medical management of USMI in male dogs is less rewarding than in bitches. Attempts have been made to manage this condition surgically using either urethral bulking agents such as Teflon or by relocating the intrapelvic bladder neck to an intra-abdominal position by vas deferentopexy. This paper reports the response to prostatopexy in male dogs with USMI. METHODS: The response to prostatopexy was determined in nine severely incontinent male dogs with USMI that were followed up for periods ranging from 10 months to five years (mean 2.3 years). RESULTS: One dog was cured, four were improved, and no improvement in the frequency or degree of urinary incontinence occurred in the remaining four animals. No complications were seen in any of the dogs. CLINICAL SIGNIFICANCE: Prostatopexy may provide a further method of treating male dogs with USMI that do not respond to medical therapy.     

Four cases of lowered urethral pressure in canine ectopic ureter

To evaluate the function of the constrictor urethrae of dogs that had urinary incontinence and were diagnosed as having ectopic ureter, the urethral pressure profile (UPP) was measured by means of a microchip catheter transducer. The UPPs (14.5 +/- 3.3 mmHg) of the four dogs suffering from ectopic ureter were much lower (p<0.001) than the UPPs of clinically healthy female dogs (35.3 +/- 5.7 mmHg). In the cases of ectopic ureter, it was shown that the UPP was lowered, and it was suggested that this would lead to the expression of urinary incontinence.     

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.     

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.     

Transurethral resection in the management of urethral and prostatic neoplasia in 6 dogs

OBJECTIVE: To assess cystoscopic transurethral resection (TUR) for the palliative management of dogs with neoplastic infiltration of the urethra. STUDY DESIGN: Prospective clinical trial. ANIMALS: Six client-owned dogs. METHODS: Cystoscopic examination and electrosurgical TUR were performed in dogs with urination difficulties caused by prostatic or urethral neoplasia. TUR was performed in a retrograde manner in female dogs and antegrade in male dogs via exploratory celiotomy and ventral cystotomy. Cystoscopic examination was used to determine the extent of neoplastic involvement of the urethra. TUR involved piecemeal removal of neoplastic tissue from the urethral lumen using an electrocautery cutting loop. Hemorrhage was controlled with a cystoscopic cauterized roller-ball. In 2 male dogs, intraoperative radiation therapy (IORT) was used to treat both prostatic neoplasia and the sublumbar lymph node bed. Surgical technique, complications, adjuvant treatment, and outcome were recorded. RESULTS: TUR was performed in 3 male dogs with prostatic carcinoma and 2 female dogs with urethral transitional cell carcinoma (TCC). In 1 female dog, TUR was attempted but not successful because of cystoscope diameter. Iatrogenic urethral perforation occurred during TUR in 3 dogs. In 2 dogs, prolonged exposure to lavage fluid resulted in clinical and biochemical abnormalities consistent with TUR syndrome. Dysuria resolved in 5 dogs within 10 days of TUR. Treatment-related complications included urinary tract infection and tumor seeding. Local tumor progression and metastasis occurred in all dogs. CONCLUSIONS: TUR (in combination with chemotherapy+/-IORT) resulted in rapid palliation of urination difficulties in male dogs with prostatic carcinoma. In female dogs with urethral TCC, however, electrosurgical TUR cannot be recommended because of a high intra- and postoperative complication rate with no improvement in postoperative management compared with historical reports of tube cystostomy. CLINICAL RELEVANCE: TUR is a novel alternative for the palliation of male dogs with prostatic carcinoma. In female dogs with urethral TCC, electrosurgical TUR does not provide any advantages compared with tube cystostomy.     

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.     

Repair of an incompetent urethral sphincter in a mare

Objective: To describe successful surgical treatment of urinary incontinence caused by a ruptured and/or transected urethral sphincter in a mare. Study Design: Clinical report. Animal: A 7‐year‐old, Swedish Warmblood mare with urinary incontinence. Methods: The urethral sphincter, which had been damaged during removal of a cystic urolith, was repaired by apposing the ends of the disrupted urethralis muscle and tunica muscularis. Results: The mare was no longer incontinent after repair of the defect by apposition of the ends of the urethralis muscle and tunica muscularis. Conclusions: Transection and/or rupture of the urethral sphincter of a mare may result in urinary incontinence. Clinical Relevance: Apposition of the ends of the ruptured or transected urethralis muscle and tunica muscularis can correct urinary incontinence caused by this defect.     

Urodynamic and morphologic changes in the lower portion of the urogenital tract after administration of estriol alone and in combination with phenylpropanolamine in sexually intact and spayed female dogs

OBJECTIVE: To compare the urodynamic and morphologic effects of the administration of estriol alone and in combination with phenylpropanolamine on the lower portion of the urogenital tract in female dogs. ANIMALS: 3 sexually intact and 3 spayed female Beagles without urinary incontinence. PROCEDURE: Dogs received estriol (2 mg, PO) once daily for 7 days followed by estriol (2 mg, PO) and phenylpropanolamine (1.5 mg/kg, PO) once daily for 7 days. Urethral pressure profilometry, diuresis cystometry, and vaginourethrography were performed before treatment (day 0) and at days 7 and 14. The maximum urethral pressure (MUP) and closure pressure (MUCP), urethral functional and anatomic profile lengths, integrated pressure (IP), plateau, distance before MUP, maximum meatus pressure, threshold pressure, threshold volume, compliance, urethral length, and vaginal length and width were measured. RESULTS: Before treatment, no urodynamic differences were observed between the 2 groups; however, vaginal length and width were significantly shorter in spayed dogs. Compared with day 0 values, estriol treatment significantly increased MUP, MUCP, and IP values at day 7, but at day 14, this effect decreased despite phenylpropanolamine administration. No morphologic changes from baseline were detected after either treatment in any dog. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that estriol mainly acts on the urethral sphincter mechanism by increasing urethral resistance in sexually intact and spayed female dogs without urinary incontinence. Administration of estriol and phenylpropanolamine did not increase the urethral resistance more than estriol alone. The urodynamic effects of estriol in female dogs with urinary incontinence remain to be elucidated.