[Colonic pouch]

The tendency towards sphincter-preserving resection for distal rectal cancers has led to a revival of the technique of coloanal anastomosis (CAA) in recent years. In order to improve functional results, creation of a colonic J-pouch in conjunction with a coloanal anastomosis (CPA) was proposed. Two different operation techniques exist: i) Double-stapling with the anastomosis close to the dentate line and ii) intersphincteric resection with the anastomosis located immediately at the dentate line. A long rectal remnant after double-stapling leads to urgency in 15% of the patients due to stool retention in the atonic remnant. No propulsive motility patterns were recorded from the pouch which is emptied passively by upper colonic peristalsis. Therefore colonic pouches should be fashioned of descending colon and should not exceed a length of 6 cm in order to prevent stool fragmentation. Under these conditions the average stool frequency is reduced from 2-6/d after CAA to 1-3/d after CPA. This effect is maximal during the first postoperative months, but is still significant after 3 years. Colonic pouch construction also leads, due to better blood supply and prevention of pelvic hematomas, to a significant decrease of the anastomotic insufficiency rate from 10.0% after CAA to 5.4% after CPA. Therefore creation of a colonic J-pouch should be combined with coloanal reconstruction if the oncologic situation allows a sphincter-preserving procedure.