The clinical application of oversleeve anastomosis in laparoscopic sphincter-preserving surgery for ultra-low rectal cancer

Objective This study aims to explore the clinical safety and feasibility of oversleeve anastomosis in laparoscopic sphincter-preserving surgery for ultra-low rectal cancer. Methods From April, 2018 to February, 2019, we conducted laparoscopic sphincter-preserving surgery using the oversleeve anastomosis technique in patients with ultra-low rectal cancer in Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Data regarding clinical characteristics, pathological characteristics, surgical and postoperative outcomes, perioperative complications and anal functions were collected and analyzed. Results We successfully performed laparoscopic sphincter-preserving surgery with the oversleeve anastomosis technique in 40 patients, including 2 patients receiving prophylactic stoma due to bad blood supply of the colonic stump. Among the patients, 21(52.5%) patients received neoadjuvant therapy. The median distance of the tumor from the anal verge was 4.0 cm. The median operation time was 166.5 minutes and intraoperative blood loss was 20.0 mL. The median length of tumor was 2.5 cm. The median proximal and distal resection margin was 10.63 cm and 1.0 cm. The median time to ground activity, time to fluid diet intake, time to flatus, and length of hospital stay were 19.0 hours, 12.5 hours, 20.5 hours and 6.0 days, respectively. The mean hospitalization cost was 47 646.0 RMB. During the follow-up period, the median time of colonic stump retracted back to the rectal cavity was postoperative day 12.0. Four patients (10%) experienced anastomosis leakage, one patient (2.5%) experienced colonic stump bleeding, four patients (10%) experienced perianal fecal dermatitis and two patients (5%) experienced anal pain. All of them recovered after symptomatic treatment. The low anterior resection syndrome (LARS) score was used to evaluate the anal function on 3 months after surgery. 8 patients (20%) had no LARS, 23 patients (57.5%) had minor LARS, and 9 patients (22.5%) had major LARS. No tumor recurrence or metastasis were observed in any patient. Conclusions This study indicates that oversleeve anastomosis shows promise as a safe and feasible procedure with satisfactory short-term outcomes in laparoscopic sphincter-saving surgery without the routine use of prophylactic stoma for ultra-low rectal cancer. But the long-term outcomes need to be explored. Key words: Rectal neoplasms; Laparoscopes; Ultra-low rectal cancer; Oversleeve anastomosis; Sphincter-saving surgery; Anal function