| Abstract: | Total colectomy and the construction of an ileal pouch reservoir that preserves the patient's continence has become a surgical option for the treatment of patients who undergo total colectomy. By using histologic, electron microscopic, and morphometric methods, the histoarchitecture of the terminal ileal pouch, now functioning as a neorectum, was compared with preoperative biopsies from the normal terminal ileum, transverse colon, and rectum from patients undergoing the construction of a pouch as well as controls. Twelve patients, each of which had undergone a total colectomy with an ileal J-pouch anal anastomosis in our hospital between 1984 and 1987, were included in the study. Over a three year period a progressive transformation to a colonic type mucosa was observed in the ileal pouch. While total mucosal thickness remained unchanged, the number and size of the crypts increased dramatically, making some specimens indistinguishable from normal colonic mucosa on histologic examination. The number of mucus producing goblet cells and Paneth cells increased, whereas the endocrine cell population demonstrated no change. The possible metabolic and physiologic consequences of this mucosal transformation are discussed. |
