Patterns of distribution of endoscopic and histological changes in the ileal reservoir after restorative proctocolectomy for ulcerative colitis. A long-term follow-up study.

Abstract

This study was undertaken to assess the long-term macroscopic appearance of the ileal reservoir after restorative proctocolectomy for ulcerative colitis, to determine whether there is any correlation between macroscopic and histological changes and whether the distribution of these is homogeneous, focal or patchy. No study has examined the macroscopic appearance of the ileal reservoir over a long period and it is still unknown to what degree histological changes are diffuse or patchy. Moreover, the relationship between macroscopic and histological changes is poorly understood. Fifty-nine patients were examined by one clinician (PSC) 5.3-14.5 years (median 8.2 years) postoperatively. A rigid sigmoidoscopy of the reservoir was performed. Four zones in the posterior midline at 5-cm intervals from the ileoanal anastomosis were inspected. At each level a macroscopic score of severity of inflammation was given and a biopsy taken. The degree of acute and chronic inflammation was assessed using a histopathological scoring system. All reservoirs showed macroscopic abnormalities, which were more marked distally in 14 (24%). There was no case in which severity of inflammation was greater in proximal than in distal zones. Endoscopy overall correlated with both acute and chronic histological changes. On histological examination the patients could be divided into three groups as follows: (1) all four biopsies were normal (group 1, n = 8, 14%), (2) the score of acute and chronic inflammation decreased from distal to proximal zones (group 2, n = 25, 42%) and (3) all four biopsies were abnormal with the same score (group 3, n = 26, 44%). The latter group significantly correlated with a present or past history of pouchitis. The study has shown that when there is a gradation of inflammation within the ileal reservoir this is more severe in distal than in proximal zones.