Laparoscopic-Assisted Modified Intersphincter Resection for Ultralow Rectal Cancer

Haiyang Zhou, Canping Ruan, Zhiguo Wang, Zhiqian Hu

Intersphincter resection (ISR) is considered to be a superior technique offering sphincter preservation in patients with ultralow rectal cancer.1 Because high-definition laparoscopy offers wider and clearer vision into the narrow pelvic cavity and intersphincteric space, ISR has been further refined.2 However, functional outcome after ISR has not been optimal. More than half of patients receiving ISR suffer partial or even complete anal incontinence.3 We therefore propose a laparoscopic-assisted modified ISR, with the aim of improving sphincter function following ISR. The video describes the technique for performing such laparoscopic-assisted modified ISR in a 62-year-old woman with ultralow rectal cancer (3 cm from anal verge). Preoperative staging by endorectal ultrasound and pelvic magnetic resonance imaging revealed stage I rectal cancer (cT2N0M0). The operation consisted of an abdominal and a perineal phase. The abdominal phase routinely involved colonic mobilization with high ligation of inferior mesenteric vessels, total mesorectal excision (TME), as well as transabdominal intersphincteric dissection. The procedure for laparoscopic TME was performed according to our published method.4 Along the TME dissection plane, the puborectalis could be reached and the intersphincteric space was entered posterolaterally. The hiatal ligament at the posterior side of the rectum was transected afterwards. The dissection of the intersphincteric space was continued caudally at the anterior side of the rectum. The distal bowel wall was mobilized for 2 cm from the lower edge of the tumor to obtain adequate distal margin. At this point, circular dissection of the intersphincteric space was completed. After the abdominal phase, perineal dissection was performed with wide exposure by use of a hooked self-retaining retractor. The lower margin of the tumor was identified under direct vision. We developed a modified ISR technique. Resection of the mucosa and internal sphincter was initiated 2 cm distal to the lower edge of the tumor at the tumor side to obtain the necessary distal margin. Meanwhile, at the opposite side of the tumor, the resection line was just above the dentate line so that partial dentate line could be preserved. After removal of the specimen en bloc per anus, the pelvic cavity was generously irrigated with diluted povidone iodine solutions. The distal margin of the specimen was then examined by frozen section for presence of cancer. If clear, coloanal anastomosis was performed using a handsewn technique. The colon was rotated 90° and anastomosed to the anal canal with interrupted absorbable 3-0 sutures. Finally, a pelvic suction drain was placed, and a temporary diverting stoma made in the terminal ileum. There were no intraoperative complications. The operating time was 180 min. Blood loss was 50 mL. The distal margin was clear, and the final pathology was pT2N0M0. The patient underwent an uneventful recovery. She began sphincter-strengthening exercises 2 weeks after surgery. The stoma was closed after examinations 3 months later. No local recurrence or distant metastasis was found. At 12-month follow-up, in terms of sphincteric function, the patient was continent to solids, liquids, and flatus. Laparoscopic-assisted modified intersphincter resection for ultralow rectal cancer is safe and feasible. This technique should be considered whenever possible as a means to offer sphincter preservation and improve sphincter function in patients with ultralow rectal cancer.