TOTAL REPLACEMENT OF URETHRAL MUCOSA WITH ORAL-MUCOSA IN DOGS

Purpose: If the urethral mucosa is replaced by another mucosa, urethra l recurrence might decrease in patients who undergo neobladder constru ction for bladder cancer. We determined whether such replacement is po ssible. Materials and Methods: Six dogs underwent an operation consist ing of a longitudinal urethral incision at its full length and immedia te closure. In 6 other dogs, after the urethral mucosa was totally rem oved, a tubularized sublingual mucosa was closely set inside the ureth ral lumen. Postoperatively, the urinary stream and external meatus wer e observed every day. To measure urine leakage, a 10-minute pad test w as performed once a month. All dogs were sacrificed 3 to 12 weeks afte r the operation for histological examination of the urethra. The excis ed urethras were examined with a 12F catheter for urethral patency. Re sults: All dogs were continent postoperatively. The results of the 10- minute pad test showed no significant difference in the weight increas e of the pad among the control, sham-operated and mucosa-replaced dogs . Urethral stricture developed in 1 mucosa-replaced dog. Histological examination revealed that all of the grafted oral mucosa survived in t he urethra. Conclusion: These results indicate that the urethral mucos a can be replaced by oral mucosa without damaging the continence mecha nism in female dogs.