Transanal Rectosigmoidectomy Using a Single Port in a Swine Model

Background. Natural orifice transluminal endoscopic surgery (NOTES) and single access surgery are emerging techniques that reduce surgical invasiveness. This study was performed to evaluate the feasibility of NOTES transanal rectosigmoidectomy using a single port in a swine model. Methods. Ten male pigs were used to conduct 2 studies, 4 for a nonsurvival study and 6 for a survival study. After anesthesia, the rectum was occluded transanally with a purse-string suture, and then a single port was placed. CO₂ gas was insufflated, and full-thickness rectal dissection was extended using laparoscopic instruments as far cephalad as possible. A 5-mm trocar was placed on the abdominal wall for transabdominal laparoscopic view, and then further colonic mobilization was performed using the endoscope through the anus. When the dissection was completed, the specimen was exteriorized and colorectal anastomosis was performed using a circular stapler. In the survival study, necropsies were performed on postoperative day 7. Results. Full-thickness circumferential rectosigmoid mobilization was achieved in all cases. The mean length of resected colon was 10 cm (range = 8-15 cm). No anastomotic defects were noted. All resected rectosigmoid specimens were grossly intact. No mortality or significant postoperative complications was observed in the survival group. On necropsy, a small abscess in the pelvic cavity was noted in 1 case and bladder distention was noted in 3 cases. Conclusions. NOTES transanal rectosigmoidectomy using the single port is feasible and safe. Further experimental studies are warranted, especially in human cadaver model.