Morphological analysis of the residual rectal mucosa in 12 postoperative ulcerative colitis patients

Abstract

Background: There are no reports on the degree of inflammation in the residual rectal mucosa in asymptomatic UC patients after an operation for ileal pouch anal canal anastomosis (IACA).
Methods: We studied the residual rectal mucosal biopsies and rectal mucosa from the surgical specimens of 12 asymptomatic postoperative UC cases. We analyzed the degree of inflammation, including crypt architecture and mucus content in the rectal mucosa.
Results: Two pathological active cases (16.7%), four resolving cases (33.3%), and six remission cases (50%) were observed in the residual rectal mucosa. In terms of the degree of pathological inflammation in the residual rectal mucosa, one case (1/12, 8.3%) was upregulated, seven cases (7/12, 58.3%) were stable, and four cases (4/12, 33.3%) were downregulated compared with the rectal mucosa of the surgical specimens.
Conclusions: We determined the natural history of the degree of inflammation on the residual rectal mucosa in postoperative UC patients. Eight cases (8/12, 66.6%) of asymptomatic UC patients were associated with prolonged inflammation after an IACA operation in the residual rectal mucosa compared with that in the rectal mucosa of the surgical specimens. Therefore, we could identify patients with prolonged inflammation in asymptomatic UC cases by a residual rectal mucosal biopsy.