Selective preservation of the anal transition zone in ileoanal pouch procedures.

PURPOSE: A prospective trial was conducted to evaluate use of certain preoperative criteria in the choice of operative technique for ileal pouch-anal anastomosis (IPAA). Handsewn vs. stapled anastomotic techniques were compared as was preservation vs. excision of the anal transition zone (ATZ).
METHODS: Over an 18-month period, 40 consecutive patients underwent restorative proctocolectomy with IPAA for ulcerative colitis (31 cases) or familial adenomatous polyposis (9 cases). In 28 patients, ATZ was completely excised, by either a transanal mucosectomy with handsewn anastomosis (Group I, 13 cases) or by double-stapled technique (Group II, 15 cases). The ATZ was preserved and the anastomosis was double-stapled in colitis patients with suboptimum sphincter function and/or greater than 50 years of age in the absence of dysplasia or severe distal proctitis (Group III, 12 cases).
RESULTS: Groups I and II patients were homogeneous in their preoperative variables and had equivalent functional outcome. Group III patients were older (P = 0.0001), with weaker preoperative anal sphincter resting tone (P = 0.024). Compared with Groups I and II, patients in Group III had significantly greater 24-hour stool frequency (P = 0.0056), daytime stool frequency (P = 0.0125), and incidence of daytime fecal seepage (P = 0.007). There was no significant difference in other outcome variables in Group III patients. There was no difference in morbidity in the three groups.
CONCLUSIONS: Transanal mucosectomy with handsewn anastomosis provided early functional results equivalent to low anal transection with double-stapled IPAA in younger patients with excellent preoperative sphincter function. A double-stapled technique with preservation of the ATZ may be reserved for older patients, with poorer anal sphincter function, at minimum dysplasia/cancer risk, to optimize continence figures.