Canis ISSN: 2398-2942

Urethral sphincter mechanism incompetence (USMI): surgical management

Synonym(s): Colposuspension for urinary incontinence

Contributor(s): Jill Sammarco, Pieter Nelissen

Introduction

  • The surgical approaches to the management of acquired urinary incontinence Urinary incontinence associated with urethral sphincter mechanism incompetence (USMI) in female dogs are discussed below.

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 fully understood:
    • Acquired incontinence may be linked to ovariohysterectomy Ovariohysterectomy and the presence of a 'pelvic bladder' Pelvic bladder.
    • Obesity 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 Ureter: ectopic should also be considered.

Advantages

  • Surgery, when successful, precludes the need for on-going medical management.
  • Colposuspension has been reported to produce immediate continence in 53% of dogs suffering from confirmed USMI.
  • Urethropexy has a success rate comparable to colposuspension. Postoperative complications were observed in approximately 20% of patients.
  • Combined urethropexy/colposuspension: a recent publication described colposuspension combined with urethropexy in a single procedure, giving reported resolution of incontinence in 70% with a low complication rate of 10% comprising transient dysuria.
  • Artificial urethral sphincters (AUS): although early reports had mixed results, the reported success rates have improved significantly in recent years, with a 2013 study reporting 22/25 patients as having a median continence score of  9 (where 1 = constant leakage and 10= completely continent). 
  • Submucosal urethral collagen injection: this is typically considered under the heading of 'conservative' treatment rather than surgical due to its minimally invasive mature. Urethral submucosal injections consist of endoscopic injection of bulking agents to increase urethral resistance. Teflon was the original product used; currently, collagen is the preferred option. After a single injection of collagen, temporary continence can be expected for anything from a few months to a few years.

Disadvantages

  • No surgical technique has been shown to be uniformly effective in curing acquired USMI.

Requirements

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Preparation

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Procedure

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Aftercare

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Outcomes

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Prognosis

  • The colposuspension procedure has been reported as curing incontinence in 53% of patients.
  • Other patients may have incontinence improved by surgery and require a lower dose of medical treatment than before surgery.
  • For combined urethropexy and colposuspension the reported resolution of incontinence was 70% with a low complication rare of 10% comprising transient dysuria.
  • In a study by Currao: all 18 dogs had significantly improved continence scores after AUS placement with a median follow-up time of 32 months. "Functional" continence (score  ≥9) was achieved  in 67% of dogs after AUS placement. Though only 13/18 clients were compliant with inflations, 12 of these (92%) had a functional continence score. 6 dogs (33%) did not require inflation to achieve continence. Urethral obstruction occurred as a complication in 3 dogs.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Martinoli S, Nelissen P, White RAS (2014) The outcome of combined urethropexy and colposuspension for management of bitches with urinary incontinence associated with urethral sphincter mechanism. Vet Surg 43 (1), 52-57 PubMed.
  • Currao R L, Berent A C, Weisse C et al (2013) Use of a percutaneously controlled urethral hydraulic occluder for treatment of refractory urinary incontinence in 18 female dogs. Vet Surg 42 (4), 440-447 PubMed.
  • Delisser P J, Friend E j, Chanoit G P A et al (2012) Static hydraulic urethral sphincter for treatment of urethral sphincter mechanism incompetence in 11 dogs. JSAP 53 (6), 338-343 PubMed.
  • Rose S A, Adin C A, Ellison G W et al (2009) Long-term efficacy of a percutaneous adjustable hydraulic urethral sphincter for treatment of urinary incontinence in four dogs. Vet Surg 38 (6), 747-753 PubMed.
  • Rawlings C A (2002) Colposuspension as a treatment for urinary incontinence in spayed dogs. JAAHA 38 (2), 107-110 PubMed.
  • Rawlings C A, Barsanti J A, Mahaffrey M B et al (2001) Evaluation of colposuspension for treatment of incontinence in spayed female dogs. JAVMA 219 (6), 770-775 PubMed.
  • 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 Surg 27 (2), 94-104 PubMed.
  • 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 Vet 18 (5), 525-540 VetMedResource.
  • Gregory S P, Holt P E (1994) The immediate effect of colposuspension on resting and stressed urethral pressure profiles in anesthetized incontinent bitches. Vet Surg 23 (5), 330-340 PubMed.
  • Holt P E (1990) Long-term evaluation of colposuspension in the treatment of urinary incontinence due to incompetence of the urethral sphincter mechanism. Vet Rec 127 (22), 537-42 PubMed.
  • Holt P E (1985) Urinary incontinence in the bitch due to sphincter mechanism incompetence: surgical treatment. JSAP 26 (5), 237-46 VetMedResource.


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