Chemical ablation of the bladder urothelium and intestinal de-epithelialization in augmentation cystoplasty: An experimental study

ABSTRACT

To determine the chemical de-epithelialization effect of protamine sulphate and urea treatments on the bladder epithelium and mucosa of the ileal segments used in augmentation cystoplasty using segment. Three groups of dogs [5 dogs in each one] were used in the study. All groups underwent augmentation cystoplasty using ileal segment. The first one [Group I] was a control group with no treatments after operation, the bladder was filled with normal saline and emptied after 30 minutes and the catheter was removed. The second group [Group II] was treated through infusion of the augmented bladder by 5 mg/ml protamine sulphate for 15 minutes. The bladder was emptied and filled with urea at concentration of 100 gm/L solution for 15 minutes then emptied, and the catheter is removed. The third group [Group III] was infused with the two drugs but in a double concentration. Biopsies from the intestinal and bladder segments were taken immediately after augmentation cystoplasty and after an interval of one month and evaluated microscopically for epithelial changes. At the same time, 24-hour urine was collected for determination of urine mucoprotins among the studied groups. Serum electrolytes; urea nitrogen and creatinine were within normal values in all groups of the study. The use of protamine sulphate and urea as chemical de-epithelialization agents for the bowel segment had led to atrophy of the mucosal villi and decrease number of goblet cells significantly so decreasing the absorptive capacity of the villi and secretory capacity of the goblet cells. Mucoprotein measurement immediate and at one month postoperatively showed that there was insignificant difference in mucoprotein in urine of 24 hours immediate postoperative between all groups. On the other hand, there was a significant difference between all groups after one month. Also, mucoprotein secretion in Group II was significantly less than that of Group I [P < 0.05]. While as regard mucoprotein secretion in Group III, the decrease was highly significant than that in Groups I and II [P < 0.001]. De-epithelializatjon of both the bladder and intestinal segments occurred promptly by using protamine sulphate and urea. This is supposed to be followed by reepithelialization by transitional epithelium later on. These results were confirmed by the decreased mucoprotein secretion in urine. This approach may be of possible use as a chemical ablation for the intestinal mucosa used in the augmentation cystoplasty or ileal neobladder and as a possible treatment alternate for bladder carcinoma in situ