Selective preservation of the anal transition zone in ileoanal pouch procedures

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).

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).

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.

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.