Intestinal de-epithelialization and augmentation cystoplasty: An animal model

An animal model of augmentation cystoplasty was developed in New Zealand rabbits to study the effects of intestinal de-epithelialization on subsequent re-epithelialization by bladder urothelium. Methods. Twenty-four rabbits underwent augmentation cystoplasty using intestinal segments that were either treated with protamine sulfate and urea solution or else anastomosed with an intact epithelium. Half of the rabbits receiving the de-epithelialized intestinal segments were subjected to glycosaminoglycan replacement therapy by administration of intravesical heparin. Experimental and control rabbits were sacrificed at 1-, 2-, and 3-month intervals. Histologic examination of the augmented sections showed small areas of urothelium growing over the intestinal epithelium (approximately 15%). The heparin-treated group demonstrated the greatest amount of re-epithelialization. There was no obvious histologic difference in the amount of collagen present in the augmented tissues in any of the experimental groups. In a preliminary study, New Zealand rabbits appear to be satisfactory as an experimental animal for studying the augmentation cystoplasty procedure and for the development of therapeutic interventions for enhancing epithelial growth. Protamine and urea will de-epithelialize the bowel and heparin may promote epithelialization of augmented intestinal segment by transitional epithelium.