The operative treatment of ulcerative colitis has changed with the development of the stapled technique of pouch construction and the procedure of double-stapled ileal pouch-anal anastomosis (IPAA). This technique is being used at many specialist centres as the procedure of choice for restorative proctocolectomy (RPC) for ulcerative colitis because of its many advantages, including a shorter operating time, a comparatively easier technique owing to the omission of the mucosectomy, a lower rate of pelvic sepsis and also some evidence that the reduced anal manipulation and preservation of the anal transitional zone mucosa lead to a better functional outcome. However, the major theoretical disadvantage of this technique is the possible development of dysplasia and eventually carcinoma in the retained mucosa. The aim of this study was to evaluate this risk of dysplasia in the retained anal mucosa in patients with ulcerative colitis who underwent RPC with a double-stapled IPAA without mucosectomy. Patients and methodsThe records of 109 patients who underwent RPC with nonmucosectomy double-stapled IPAA for ulcerative colitis from September 1988 to December 1993 were reviewed. A minimum follow-up of 1 year was obtained. Patients who had IPAA for any condition other than ulcerative colitis were excluded, as were those with ulcerative colitis who were found to have carcinoma or dysplasia in the colon at the time of surgery. The histology of the distal rectal doughnut as well as the follow-up biopsies were reviewed by one of two pathologists. Follow-up studies included clinical evaluation with digital examination, endoscopy and random 2-mm pinch biopsies of the retained mucosal cuff. These biopsies were undertaken at the time of ileostomy closure and then annually, and any dysplasia was noted and graded. If the doughnut and two consecutive biopsies revealed squamous epithelium, further follow-up biopsies were not performed. ResultsThere were 69 men (mean age 42.5 (range 14-72) years) and 40 women (mean age 3 7 5 (range 23-71)years). A total of 109 rectal doughnuts were reviewed. During follow-up of 1-6 (mean 2.6) years, a total of 186 biopsies of the anal mucosa were examined (mean 1.7 follow-up biopsies per patient; all patients had at least one biopsy). Only one patient was noted to have low-grade dysplasia in the distal rectal doughnut at the time of operation. Four 1406 follow-up biopsies of the retained mucosa in this patient over a period of 3 years, however, revealed no evidence of dysplasia. There was no recorded case of dysplasia in the follow-up biopsies of the retained mucosa in any patient in the series. No carcinomas were noted, either at the time of surgery or during the follow-up period. DiscussionDouble-stapled IPAA has become the procedure of choice in patients with ulcerative colitis after RPC. Ambroze et al. ' have questioned the advisability of nonmucosectomy ileoanal reservoir because of the potential for malignant change in the retained mucosa. However, there have been no reports of carcinoma in the ...