Augmentation cystoplasty in rats: development of an animal model

An animal model of the Long-Evans species of rats was developed to study the short-term and long-term effects of enterocystoplasty. Various enterocystoplasties were performed in 39 rats, including ileal in 29, colonic in 5 and gastric in 5. The followup period was 3 months. Frequency and pattern of voiding, 24-hour urinary collection for mucus production, and blood and urinary electrolytes were analyzed. All voiding parameters, renal function and biochemical studies remained normal. Mucus production was higher in the gastrocystoplasty and colocystoplasty than in ileocystoplasty cases. Postmortem histopathological examination of the enteropatch was performed, which showed urothelialization of the graft with native transitional epithelium extending over the junctional margin of the graft and covering the enteropatch mucosa. The enteropatch muscle orientation was maintained in all 3 types of grafts. We believe that the Long-Evans species of rats is a good model for the study of enterocystoplasty.