The immediate effect of colposuspension on resting and stressed urethral pressure profiles in anaesthetized incontinent bitches

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.

Evaluation of the ratio of collagen type III to collagen type I in periurethral tissues of sexually intact and neutered female dogs

OBJECTIVE

To determine the ratio of collagen type III to collagen type I in the periurethral tissues of sexually intact and neutered female dogs.

ANIMALS

8 neutered and 34 sexually intact female dogs.

PROCEDURES

Tissues were obtained from female dogs euthanized for non-urinary tract-related reasons. Indirect immunofluorescent antibody detection of type I and collagen type III was performed by use of confocal microscopy on 2 periurethral samples from each dog, and the ratios of collagen type III to type I area fraction and total area were determined.

RESULTS

No significant differences were detected in the collagen ratios of periurethral tissues between sexually intact and neutered female dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

In contrast to differences in periurethral collagen content found between pre- and postmenopausal women, such differences may not occur in dogs. This implies that changes in pelvic organ support structures may not play an important role in urinary incontinence in neutered female dogs. Further evaluation is needed to determine the role of age on collagen and pelvic organ support structures in the pathogenesis of canine urinary incontinence.

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.

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.

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.

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.

Immediate urodynamic and anatomic response to colposuspension in female Beagles

OBJECTIVE

To characterize urodynamic function and anatomy before and after colposuspension in anesthetized female Beagles.

ANIMALS

12 adult female Beagles. PROCEDURE; During general anesthesia (thiopental sodium induction and halothane maintenance), urethral pressure profiles, leak point pressure measurements with a 50-ml bladder volume, positive contrast cystograms, and retrograde vaginourethrocystograms were performed. A caudal midline laparotomy was used to perform colposuspension. Urodynamic and radiographic studies were repeated after surgery.

RESULTS

Leak point pressures were increased (120 to 168.9 cm H2O), and maximum urethral closure pressures decreased (43.7 to 19.3 cm H2O ) after colposuspension. The urethra and bladder were moved cranially; the external urethral orifice was positioned closer to the pelvic cavity, and the neck of the bladder was positioned more cranially into the abdomen. Length of the urethra, as measured by use of vaginourethrocystograms, was increased by 3%. As measured by use of urethral pressure profiles, total profile length was increased by 19.9%, and functional profile length was increased by 19.2%.

CONCLUSIONS AND CLINICAL RELEVANCE

Increased leak-point pressure correlated with the expected clinical improvement attributable to colposuspension. Increased exposure of the urethra to abdominal and pelvic cavity pressures may be the mechanism by which incontinent dogs become continent after colposuspension. Results of the leak-point pressure test may correlate with clinical behavior before and after colposuspension for treatment of 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.