Comparison of urethral pressure profilometry and contrast radiography in the diagnosis of incompetence of the urethral sphincter mechanism in bitches

ACVIM consensus statement on diagnosis and management of urinary incontinence in dogs

Urinary incontinence (UI) is a disorder of micturition that can occur in dogs of any age, sex, and breed depending on the underlying cause and time of onset. Diagnosis and treatment for various causes of UI in dogs have been described by multiple comprehensive single author review articles, but large prospective clinical trials comparing treatment outcomes in veterinary medicine are lacking. The objectives of this consensus statement therefore are to provide guidelines on both recommended diagnostic testing and treatment for various causes of UI in dogs. Specifically, pathophysiology directly related to the canine urinary system will be reviewed and diagnostic and therapeutic challenges will be addressed. A panel of 12 experts in the field (8 small animal internists [L. Adams, J. Bartges, A. Berent, J. Byron, J. Foster, A. Kendall, S. Vaden, J. Westropp], 2 neurologists [J. Coates, N. Olby], 1 radiologist [G. Oetelaar], and 1 surgeon [C. Adin]) was formed to assess and summarize evidence in the peer-reviewed literature and to complement it with consensus recommendations using the Delphi method. Some statements were not voted on by all panelists. This consensus statement aims to provide guidance for management of both male and female dogs with underlying storage or voiding disorders resulting in UI.

Retrospective analysis after endoscopic urethral injections of glutaraldehyde-cross-linked-collagen or dextranomer/hyaluronic acid copolymer in bitches with urinary incontinence

OBJECTIVES

To evaluate the outcome of endoscopic injection of two different bulking agents, glutaraldehyde cross-linked collagen and dextranomer/hyaluronic acid copolymer into the urethral submucosa in female dogs with urinary incontinence caused by urethral sphincter mechanism incompetence.

MATERIALS AND METHODS

Retrospective review of records and follow-up communication with owners of dogs that received an endoscopically guided urethral bulking procedure. In each dog, either cross-linked collagen (2007 to 2011) or dextranomer/hyaluronic acid copolymer (2012 to 2015) was used. At least three injections were made in a circular arrangement in the midurethral region until the urethral lumen was closed.

RESULTS

Complete questionnaires were available from 50 of 100 pet owners. The mean interval between the treatment and interview was 67 (range: 57 to 114) months in the cross-linked collagen group and 19 (range: 2 to 48) months in the dextranomer/hyaluronic acid copolymer group. The mean duration of continence was 45∙8 months (range: 12 to 84 months) in the cross-linked collagen group and 20∙5 months (range: 12 to 48 months) in the dextranomer/hyaluronic acid copolymer group. The success rate at 6 months or more after the procedure was 71% after the injection of cross-linked collagen and 58% after injection of dextranomer/hyaluronic acid copolymer. One minor complication (transient haematuria) occurred in one dog. There were no major complications.

CLINICAL SIGNIFICANCE

Urethral injection of dextranomer/hyaluronic acid copolymer in bitches with urethral sphincter mechanism incompetence is a useful alternative to cross-linked collagen injection, which is no longer available in the European market. Dextranomer/hyaluronic acid copolymer injection is a minimally invasive alternative to surgical procedures and has a low complication rate.

Treatment of urethral obstruction secondary to caudal bladder displacement, trigonal invagination, and urethral kinking in a dog

CASE DESCRIPTION A 15-year-old spayed female mixed-breed dog was evaluated for a 7-week history of stranguria, pollakiuria, and intermittent urethral obstruction. CLINICAL FINDINGS On initial evaluation, the patient had persistent stranguria with lack of urine production; after multiple unsuccessful attempts to urinate, a large volume of urine was produced. Prior to voiding the large volume, the urinary bladder was not palpable during examination. Abdominal ultrasonography confirmed caudal displacement of the urinary bladder, and the urethra and trigone could not be located ultrasonographically. Positive-contrast cystourethrography and CT confirmed caudal displacement of the urinary bladder and also revealed trigonal invagination and urethral kinking; dysuria was attributed to these findings. TREATMENT AND OUTCOME Surgical repositioning of the lower urinary tract was performed. The urinary bladder was moved cranially and was fixed in place along the left lateral aspect of the body wall by cystopexy. After surgery, positive-contrast cystourethrography revealed a more cranial positioning of the urinary bladder and straightening of the urethra with no urethral kinking or trigonal invagination. Immediately after surgery, stranguria had resolved and the patient was able to void normally. Two years after surgery, the dog was reported to be urinating normally. CLINICAL RELEVANCE Surgical correction of caudal urinary bladder displacement with cystopexy led to resolution of trigonal invagination, urethral kinking, and urethral obstruction in the dog of the present report. Trigonal invagination and urethral kinking, although uncommon findings, should be considered as possible causes of dysuria in dogs.

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.

Clinical and radiographic findings compared with urodynamic findings in neutered female dogs with refractory urinary incontinence

Possible correlations were investigated between the clinical and urodynamic findings in 77 neutered female dogs with urinary incontinence refractory to standard medical management. The clinical data used in the analysis were age, bodyweight, breed, the characteristics of the dribbling of urine and whether it developed before or after neutering, the type of response to previous treatments, signs of polyuria/polydipsia, and the results of urinalysis and culture. In 50 of the dogs, a standardised contrast radiographic examination was made to locate the neck of the bladder and to assess the morphology of the bladder. These findings were analysed for their correlation with the results of multichannel urethral pressure profilometry and diuresis cysto-urethrometry. Logistic regression analysis revealed that neither the clinical nor the radiographic findings could predict any of the abnormal urodynamic findings. Functional abnormalities of the bladder, such as a low compliance, detrusor instability, or a low bladder capacity may therefore be particularly difficult to detect in dogs with urinary incontinence.

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.