The effect of gastric augmentation on bladder function.

Gastrocystoplasty was performed in 29 female and 14 male patients 1 to 23 years old (average age 11 years). Urodynamic studies were completed in 20 patients preoperatively and within 6 months postoperatively. When postoperative studies were compared with the preoperative evaluation, it was noted that overall capacity increased an average of 220% (range 20 to 750%). Compliance also improved dramatically postoperatively. Bladder pressures increased from a mean volume of 34% of capacity preoperatively to 73% of the post-augment capacity. The average maximum filling pressure decreased by 32%, from 57 to 39 cm. water. Uninhibited contractions resolved completely in 6 of 10 patients who had them preoperatively. No one had uninhibited contractions postoperatively. Cyclical contractions of the stomach segment not exceeding 50 cm. water developed in 6 patients. The gastric patch seems to be an adequate source for improving the dynamics of a poorly functioning detrusor muscle in most patients. When a diamond-shaped patch of stomach is harvested and added to the bladder a spherical configuration is created, enhancing the storage properties. This result is in sharp contrast to other bowel segments, which must be detubularized to produce a suitable reservoir. The long-term effects of gastric augmentation remain to be determined.