Chapter 14: Table of Contents
Canine Urethrostomy – Procedure
With the patient in dorsal recumbency, a sterile urinary catheter is advanced to the level of the obstruction or if possible into the urinary bladder. An elliptical incision is made at the base of the scrotum leaving enough cutaneous tissue to allow tension-free apposition of the urethral wall and skin. Open castration is performed in intact dogs. The penile retractor muscle, which runs along the ventral penis and urethral wall is dissected and retracted to one side to expose the urethra. Palpate the urinary catheter to identify the urethra (dark blue structure) and incise it along it’s midline with a #11 or #15 blade over a 2.5 to 5 cm length; the incision can be extended with tenotomy or Iris scissors. Hemorrhage is controlled with gentle pressure applied with a gauze sponge. Do not cauterize or ligate the urethral edges.
Although the urethrostomy site will appear long, remember that it will decrease by 1/3 to 1/2 of the original length after healing. Appose the urethral mucosa to the cut skin edge without tension using 4-0 or 5-0 monofilament, non-absorbable suture (polypropylene is ideal). Non-absorbable suture will need to be removed after healing has occurred but will lead to less inflammation and tissue fibrosis. Sutures should include good bites of tissues and should correctly appose the skin and urethral mucosa. A retrospective evaluation of 38 dogs that underwent a scrotal urethrostomy closed using a simple interrupted pattern revealed that postoperative bleeding requiring hospitalization was noted for an average of 4.2 days and up to 10 days after surgery. Although a simple interrupted pattern is acceptable, a study evaluating a modified continuous pattern for closure of scrotal urethrostomy reported that the technique was faster and resulted in less postoperative hemorrhage (amount and duration) than other closure techniques. (Newton 1996) This technique is described as the three needle bite since it incorporates a bite of mucosa, a bite of skin and a bite of tunica albuginea which adds strength to the suture line. (Newton 1996)