OBJECTIVETo evaluate the clinical efficacy of intersphincteric resection in the sphincter- preserving operation for ultra-lower rectum cancer.

METHODSThirty-one rectal cancer patients with the distal edge of the tumour less than 2 cm from the dentate line were evaluated. Eighteen advanced rectal cancer patients received preoperative chemo-radiation. Total mesorectal excision (TME) was performed with the rectum immobilized down, and the puborectal ligament and partial levator cut to the level of the dentate line. In some well-exposed patients, it was possible to further immobilize the rectum between the external sphincter ring and the rectum inner sphincter wall. In anal approach,good exposure was attained and the cut-line was made vertically to the anal canal 2 cm below the lower edge of the tumor, and further intersphincteric immobilization was made upright. Colon or colon pouch were anastomosed to the distal anal wall.

RESULTSThere was no peri-operative death. Thirty patients had good fecal control. Twenty-nine patients showed no evidence of recurrence or metastasis after follow-up for 12 months. Recurrence occurred in one case 1 year after operation. Another one had higher CEA 19.9 level, but without evidence of metastasis.

CONCLUSIONRadical resection can be attained and anal sphincter preserved by intersphincter resection which is an alternative sphincter-preserving operation.