Urethral Lengthening is a surgical alternative for treatment of canine incontinence.
Urethral lengthening has been used to treat congenital USMI in cats and dogs with a notably shortened urethra resulting in pelvic displacement of the bladder neck. A significantly short urethra (urethral hypoplasia) prohibits cranial movement of the bladder neck into the abdominal cavity, eliminating the ability to use surgical procedures such as colposuspension, urethropexy, and urethral slings to treat USMI. Reconstruction of the bladder neck and the use of ventrally based bladder tube flaps have been reported to taper the bladder neck, thereby elongating the proximal urethra. Excellent or good results were reported in seven of eight cats treated with this technique, and a good outcome was described in one dog.16,17 Urethral lengthening using bladder wall flaps has also been described for treatment of urinary incontinence in people. This technique may warrant further consideration with expanded clinical evaluation for the treatment of USMI in small animals with pelvic bladder.
Position the patient in dorsal recumbency and clip and aseptically prepare the ventral abdomen. Perform a caudal midline celiotomy from the umbilicus, extending over the cranial aspect of the pubis. Expose the bladder, urethra, and uterine body remnant. Make a ventral cystotomy incision, extending into the proximal urethra, and create two V-shaped flaps in the ventral aspect of the ventral bladder wall, using the caudal extent of the incision in the proximal urethra as the point of both V flaps. The widest portion of each V flap is located at the level of the ureteral orifices, at the tip of the trigone. Use 4-0 monofilament absorbable sutures in a continuous or interrupted pattern to primarily close the linear defect created in the ventral wall of the bladder neck and proximal urethra, thereby decreasing the diameter of the bladder neck lumen and elongating the proximal urethra.
The initial descriptions of this procedure recommended suturing the bladder flaps to each other to prevent a loss in bladder capacity.17 Alternatively, resection of the bladder flaps makes the surgical procedure and closure much simpler, and the resultant loss of bladder capacity is usually inconsequential. Due to the tremendous regenerative capacity of the bladder, presurgical vesicular capacity is restored within a few weeks to months after surgery.
Increased frequency of urination and stranguria are the most commonly anticipated adverse effects after reconstructive procedures to lengthen the urethra. Stranguria may be noted for several weeks. Avoid placement of a urethral catheter unless complete urethral obstruction occurs. Intermittent cystocentesis can be performed over a 24- to 36-hour period, and administration of an NSAID is indicated to reduce soft tissue inflammation of the lower urinary tract. Acepromazine administered at a low dose (0.01 to 0.025 mg/kg SC, IM, or IV q8h) may help relax the urethra, reducing stranguria and facilitating urine flow.