A surgical approach to the management of acquired urinary incontinence associated with urethral sphincter mechanism incompetence (USMI) in female dogs.
Uses
Acquired urinary incontinence, especially in spayed bitches, that is not responsive to medical therapy, or in situations where the owner rejects medical management.
The precise etiology of this disorder is not understood fully:
Acquired incontinence may be associated with hormonal consequences of ovariohysterectomy and the presence of a 'pelvic bladder'.
Obesity also contributes to the condition.
In animals with a long history of incontinence, which may be of a variable nature, congenital causes such as ectopic ureter should also be considered.
Advantages
Surgery, when successful, precludes the need for on-going medical management of the condition.
Colposuspension has been reported to produce continence in 53% of dogs suffering from confirmed USMI.
Complications associated with procedure are rare.
Disadvantages
No surgical technique has been shown to be uniformly effective in curing acquired USMI.
Alternative techniques
Medical management is usually attempted first, using estrogens and/or sympathomimetic agents, eg phenylpropanolamine to improve urethral tone. If a poor response is obtained or if side-effects are noted or owner compliance becomes poor, surgical management may be recommended with the proviso that success cannot be guaranteed.
Time required Preparation
15 min.
Procedure
40-60 min.
Decision taking Criteria for choosing test
Investigation of incontinence requires a careful and methodical approach. A thorough history, clinical examination, radiographic evaluation (including contrast radiography/excretory urography) and laboratory panel (including urinalysis) should be performed prior to surgery.
Major differentials include inflammatory/infective disorders, congenital disorders, obstructive uropathies, eg neoplasia, calculi, and neurological disease.
Urethral sphincter pressure profilometry, when available, is a useful tool in the investigation of USMI.
Risk assessment
Surgical treatment of USMI is preferable to medical management when:
Diagnosis in young animal requiring lifelong medical management.
Incontinence is poorly controlled by medical means.
Make a skin incision extending from the umbilicus to the pubis.
Undermine subcutaneous tissues to expose the prepubic tendon and associated blood vessels bilaterally.
Core Procedure
Step 1 - Continue the laparotomy and expose the bladder
Incise the linea alba and elevate and retract the bladder cranially then pack-off.
Identify the bladder neck by palpating the inflated bulb of the Foley catheter.
Using gentle blunt dissection, release the urethra from the pelvic floor. Handle the bladder with Allis tissue forceps or stay sutures.
Step 2 - Displace the bladder neck cranially
An assistant should insert one finger into the vulva and deflect the vagina cranially.
Using blunt dissection, expose the vaginal wall dorsolateral to the urethra. This entails separating fat and fascia around the ventral bladder neck/proximal urethra areas.
Step 3 - Secure the cranially displaced bladder neck
Secure the bladder neck by means of two monofilament non-absorbable sutures placed full-thickness through the vaginal walls on each side of the bladder neck. Avoid blood vessels associate with prepubic tendon.
Step 4 -
These sutures are passed through the prepubic tendon on either side of the linea alba incision, and tied. Maintain cranial traction of the vagina while these sutures are tied. Ensure that the urethra is not compromised by the vagina-prepubic tendon sutures.
Exit Step 1 -
Close the laparotomy incision in routine three-layered fashion.
Monitor for normal passage of urine in the post-operative period.
Analgesia
Analgesia is required for all laparotomy patients.
Antimicrobial therapy
Antibiotics are indicated if there is evidence of urinary tract infection, when they should ideally be based on culture and sensitivity analysis of urine.
Potential complications
Compromised urethral patency is possible if sutures have not been carefully placed.
Dyssynergia (reflex spasm of urethra on urination) within 48 hours post-operatively. If dyssynergia occurs it can be managed with oral diazepam .
Nickel R F, Wiegund U & van der Brom W E (1998) Evaluation of a transpelvic sling procedure with and without colposuspension for treatment of female dogs with refractory urethral sphincter mechanism incontinence.Vet Surg27 , 94-104.
Gookin J L, Stone E A & Sharp N J (1996) Urinary incontinence in dogs and cats. Part II; diagnosis and management.Comp Cont Ed Pract Vet18 , 525-540.
Holt P E (1990) Long-term evaluation of colposuspension in the treatment of urinary incontinence due to incompetence of the urethral sphincter mechanism.Vet Rec127 , 537.
Holt P E (1985) Urinary incontinence in the bitch due to sphincter mechanism incompetence: surgical treatment.JSAP26 , 237.
Vetstream contributor(s)
Dr Jill Sammarco BVSc MRCVS DipACVS DipECVS , 32 Oakwood Avenue, Glen Ridge, NJ 07028, USA.
In animals with a long history of incontinence, which may be of a variable nature, congenital causes such as ectopic ureter 
Avoid blood vessels associate with prepubic tendon.