A NEW METHOD FOR THE RECONSTRUCTION OF THE URINARY TRACT “BLADDER FLAP-TUBE”

Abstract

Taking a suggestion form Denis Browne's urethroplasty, I have undertaken the following experiment, in which it was found that the pediculated bladder flap posted extravesically has become a complete tube whose epithelialized canal was continuous with the bladder cavity, owing to the regenerative power of the flap epithelium. We called it as “Bladder Flap-Tube”.
Bladder of adult dog was exposed. Two parallel incisions were made at intervals of 1cm through the entire layer of bladder wall, thus forming a flap of 5-6cm length. Lifting up this flap, the bladder was closed by suturing together the outer incision edges with continuous catgut sutures. Closure of the flap roots should be made so as to prevent leakage of urine and to maintain an adequate blood supply to the flap. The abdominal wall was closed as usual, leaving a drainage tube for 2 or 3 days.
Process of development of bladder flap-tube. A few days postoperative, the cut edges of the pediculated flap posted extravesically had become adherent to the opposed bladder wall, which was covered with some granulation tissue.
This adherence became stronger, thus forming a primary tube canal between the flap and bladder wall. At the same time the regenerative growth of the flap epithelium began from its cut edges. And complete circumferential epithelialization of the canal has occured by 12 days.
After 3 weeks the granulation tissue began to take organization and to shrink, so the original cut edges of bladder flap became closer and closer to each other, while the adherence of tube to bladder became decreased. After 4-5 weeks period the separation of the flap-tube from the bladder has become very easy. At 5 weeks the flap-tube had also complete continuous muscle layers around the canal.
As the mucosa of the original bladder flap was continuous with the bladder mucosa, the newly constructed tube canal also had continuity with the bladder cavity. A valve-like action at the entry of the tube into bladder to prevent the backflow of bladder urine was confirmed.
The inner circumference of the tube canal was largest during the first 9-12 days, and owing to the rapid shrinkage in 3-5 weeks came to the width of the original bladder flap, thereafter remained constant for as long as 240 days. (The length of the flap-tube was always about the same as the original flap.)
Utillizetion of Bladder Flap-Tube.
After cutting one end of the tube from the bladder at 4-6 weeks period, we can succeed in the practical urilization of flap-tube for the reconstruction of the lower ureter or urethra in dogs and also in human beings.
As a method of urinary-tract repair, though a preliminary operation is needed 4-5 weeks before the practical application, it has the advantage that one can handle a vivid and completely formed tube made from the urinary tract itself and there are few possibilities for getting urine leakage and atrophy of the tube. Also there occurs a valve-like action at the entry of tube into the bladder.