Incidence and natural history of dysplasia of the anal transitional zone after ileal pouch-anal anastomosis

Abstract

Anal transitional zone dysplasia after ileal pouch-anal anastomosis is infrequent, is most common in the first two to three years postoperatively and may apparently disappear on repeated biopsy. Anal transitional zone preservation did not lead to the development of cancer in the anal transitional zone after five to ten years of follow-up. Long-term surveillance is recommended to monitor dysplasia. If repeat biopsy confirms persistent dysplasia, anal transitional zone excision with neoileal pouch-anal anastomosis is recommended.