LONG-TERM APPRAISAL OF THE HISTOLOGICAL APPEARANCES OF THE ILEAL RESERVOIR MUCOSA AFTER RESTORATIVE PROCTOCOLECTOMY FOR ULCERATIVE-COLITIS

Between November 1976 and December 1985, 110 patients had restorative proctocolectomy for ulcerative colitis. The histological appearances i n the reservoir mucosa were followed up in 60 of 109 survivors over 19 -173 months (median 97). The median number of biopsy specimens taken p er patient was six with a range of 3-13. These were examined by one pa thologist (ICT) unaware of the clinical details using a scoring system previously described to assess the degree of chronic and acute inflam mation. There was a significant correlation between the degree of seve rity of chronic and acute changes (r=0.6192, p<0.000001). There was no correlation between the severity of inflammation and the following va riables: preoperative duration of disease, presence of cancer or dyspl asia in the original operative specimen, extra-alimentary manifestatio ns or the type of reservoir. A significant correlation between severe inflammation and male sex was found (p<0.035). The 60 patients could b e divided into three groups based on the severity and fluctuation of h istological inflammation. In group A (n=27, 45%) chronic changes were minor and acute inflammation was never seen, In group B (n=25, 42%) ch ronic changes were more severe and there were transient episodes of ac ute inflammation. In group C (n=8, 13%) severe chronic and severe acut e inflammation were constantly present. Differentiation of the three g roups had clearly occurred within six months from closure of the ileos tomy. Patients in group C could be identified on histological criteria within weeks of closure of the ileostomy and were those exclusively a t risk of developing chronic pouchitis. Chronic pouchitis never occurr ed in patients of groups A and B. No case of dysplasia was seen. Histo logical assessment of the reservoir mucosa within a few months after c losure of the ileostomy seems to define patients who will and who will not subsequently develop pouchitis.