A Study on the Gastrocystoplasty of the Rats

Chung, In Young; Kim, Kap Byung; Park, Jae Bok

Abstract

PURPOSE: This study was to investigate how stomach flaps and graft adapt their normal function to the urinary milieu after gastrocystoplasty. Also, it was studied to find out whether the stomach graft can survive as a part of bladder and function effectively.
MATERIALS AND METHODS
The rats were divided into 5 groups; 1) normal 2) partial cystectomy 3) gastrocystoplasty with left gastroepiploic artery 4) gastrocystoplasty with stomach graft 5) gastrocystoplasty with right gastroepiploic artery. Their bladder capacity, end-filling pressure, serum electrolytes, BUN/Cr and urinalysis were measured. And histological examinations were performed periodically on group 3 and 4.
RESULTS
All rats of gastrocystoplasty with right gastroepiploic artery expired due to bleeding, vasovagal reflex and urine leakage. But most rats with left gastroepiploic artery and stomach graft survived. Their bladder capacity increased a little more than the partial cystectomy group. Their end-filling pressures were not significantly decreased compared with partial cystectomy group. Renal function and serum electrolytes remained normal throughout the study. Serum Na+ of gastrocystoplasty rats were significantly decreased compared with normal rats(p<0.05). Microscopic hematuria developed in 15% of gastrocystoplasty rats with left gastroepiploic artery. Histological examination showed the urothelialization from the site of anastomosis toward the central portion of the graft. There were hyperplastic and squamous metaplastic changes on the bladder mucosa adjacent to the transplanted gastric patch. Bladder ulceration was observed in the gastrocystoplasty group with left gastroepiploic artery, but not in the gastrocystoplasty group with stomach graft. The gastric glands were observed and alive throughout the study in the gastrocystoplasty group with left gastroepiploic artery, but were not seen at postoperative 4 weeks in the gastrocystoplasty group with stomach graft.
CONCLUSIONS
Based on the experimental data, it is suggested that augmentation gastrocystoplasty with left gastroepiploic artery pedicle is preferable to right gastroepiploic artery pedicle. It was concluded that the gastrocystoplasty using stomach graft and flap in rats could adapt to the bladder urodynamically, histologically and biochemically, and that the stomach graft could be used as one method of complete tissue graft.