An alternative treatment modality in closing bladder exstrophy: use of rectus abdominus muscle flap--preliminary results in a rat model.

The aim of this study was to find a new alternate method for bladder exstrophies with small capacity and inelasticity, and to resolve complications of other bladder augmentation techniques. In 50 Wistar albino rats, a large bladder defect was created excising at least one half of their original bladder, keeping the peritrigonal zone intact. In each rat, a 2.5 x 1-cm inferiorly based rectus abdominus muscle flap was prepared from the lower abdominal quadrant. This flap was then rotated to cover the bladder defect. The inner layer formed by the peritoneum was sutured to the edges of the bladder defect by 6-0 separate sutures. The post-operative radiologic and scintigraphic examination of the urinary system done at different intervals showed no difference from that of normal rats. The only observed disadvantage of this technique was the formation of calculi in the bladder in 8/50 rats in the late post-operative period. Post-mortem histopathologic investigations performed at different intervals showed the inner layer of the flap to be completely covered by the transitional urinary epithelium of the bladder. We think this technique is easy to perform, non-time-consuming, and has a low complication rate. It may be useful in infants with small, noncompliant, inelastic bladder exstrophies.