Saturday 10 November 2012
Occasional patients who have undergone IPAA develop persistent or recurrent episodes of pouchitis (chronic pouchitis), from which a subset also develop gastrointestinal and systemic complications that are identical to those seen in Crohn’s disease.
These complications include enteric stenoses or fistulas in the pouch or pouch inlet segment, perianal fistulas or abscesses, pouch fistulas, arthritis, iridocyclitis, and pyoderma gangrenosum.
The development of Crohn’s-like gastrointestinal complications in a patient with chronic pouchitis frequently engenders concern that the pathologist misinterpreted the proctocolectomy specimen as ulcerative colitis instead of Crohn’s disease.
Some patients develop chronic pouchitis and Crohn’s-like complications after IPAA and total proctocolectomy. They have ulcerative colitis. Crohn’s-like complications are most likely related to chronic pouchitis, which probably is a form of recrudescent ulcerative colitis within the novel environment of the pouch.
A diagnosis of Crohn’s disease after IPAA surgery should only be made when reexamination of the original proctocolectomy specimen shows typical pathologic features of Crohn’s disease, Crohn’s disease arises in parts of the gastrointestinal tract distant from the pouch, pouch biopsies contain active enteritis with granulomas, or excised pouches show the characteristic features of Crohn’s disease, including granulomas.
There are no histologic differences in the total colectomy specimens between the ulcerative colitis study patients and control ulcerative colitis patients who had a favorable clinical outcome after IPAA surgery groups.
Crohn’s-like complications and chronic pouchitis does not necessarily imply an incorrect original interpretation of ulcerative colitis by the pathologist.
Crohn’s-like complications in patients with ulcerative colitis after total proctocolectomy and ileal pouch-anal anastomosis. Goldstein NS, Sanford WW, Bodzin JH. Am J Surg Pathol. 1997 Nov;21(11):1343-53. PMID: 9351572