Restorative Proctocolectomy with Ileo-anal Reservoir, a Histopathological, Histochemical, and Electron Microscopic Study

This study was conducted to investigate the nature of colonic metaplasia in ileo-anal pouches and incidence/frequency of pouchitis in the same. Biopsy specimens from 8 patients with functioning ileal pouches were studied using routine histology, mucin histochemistry and electron microscopy, over a 2 – year period. All 8 patients had villous abnormalities in the form of blunting of villi and sub total or partial villous atrophy. 6 patients had an increase in the goblet cell population and Paneth cell hyperplasia. These changes were supported by electron microscopic findings of a decrease in number and flattening of ileal type microvilli and their transformed morphologic resemblance to colonic type microvilli. All the ileal pouches also had acquired colorectal type sulphomucin, when sections stained with Alcian-blue and High Iron Diamine – Alcian blue, were studied. However, no case of pouchitis as defined in literature, was found in this study.