Clinical application of intersphincteric resection in the anal-preserving operation for ultra-low rectal carcinoma

Abstract

To investigate the clinical application of intersphincter resection (ISR) combined with total mesorectal excision (TME) and colon-anal anastomosis in the treatment for ultra-low rectal carcinoma. To review and analyze retrospectively the data of 34 patients with ultra-low rectal carcinoma (without external anal sphincter involvement) who received treatment of ISR, TME and colon-anal anastomosis. Partial resection of internal sphincter was performed in the patients with a distal edge of the tumor greater than or equal to 2 cm from the dentate line. Subtotal removal of the rectum was performed between 1 cm and 2 cm. Total resection was performed in less than 1 cm or involvement of dentate line. Reconstruction of digestive tract was done by manual colon-anal anastomosis. The average distance from distal excised margin to the tumor was 2.3 (1.8 - 3.2) cm among 34 patients. The pathological types were as follows: 28 cases of adenocarcinoma (11 were well differentiated, 17 moderately differentiated), 1 case of papillary carcinoma and 5 cases of villous adenoma with malignant change. The postoperative pathological stages were: Dukes stage A in 28 cases, stage B in 1 and stage C in 5 cases. The pTNM staging was 28 cases in phase I, 1 in phase IIa, 4 in phase IIIa and 1 in phase IIIb. The T stages of the patients were as following: 16 Tl, 17 T2 and 1 T3. Postoperative anastomotic stenosis occurred in 3 cases, anastomotic dehiscence in 2 cases and rectovaginal fistula in 2 cases. The ability of controlling feces of patients decreased significantly in the early postoperative period, and restored gradually at 6 to 12 months after operation. Anastomotic recurrence occurred in 1 case at 5 months after operation and liver metastasis in 1 case at 40 months. With strictly grasping indications, radical resection can be attained and anal sphincter preserved by ISR combined with TME and colon-anal anastomosis. It is an effective sphincter-preserving operation.