Natural orifice transluminal endoscopic surgery applied to sigmoidectomy in survival animal models: using paired magnetic intra-luminal device

The clinical application of natural orifice transluminal endoscopic surgery (NOTES) for sigmoidectomy is associated with several difficulties that need to be overcome before wider clinical application of the procedure. The purpose of this study was to evaluate the technical feasibility and safety of transgastric sigmoidectomy in a survival animal model, as well as to evaluate the safety and usability of a custom paired magnetic intraluminal device, which we developed for the NOTES procedure. Survival experiments were conducted on 24-33-kg dogs. After anesthesia, a gastrotomy was created using double-channel endoscope, and peritoneoscopy was performed. The sigmoid colon was retracted laterally using paired magnetic intraluminal device, the mesocolon was dissected, and the branch vessel was sealed. The anvil was placed into the descending colon through anus. A proximal and distal colonic transection was then performed. The circular stapler was passed through the anus and performed end-to-end anastomosis. Afterwards the specimen was removed through gastrotomy, and the gastric incision was closed. Postoperatively, all dogs were recovered and monitored for well-being during convalescence. Reexploration was practiced under anesthesia 2 weeks after surgery for evaluation of intra-abdominal complications, and intra-peritoneal cultures for microorganism. The mean operative time was 141 (range, 122-157) min. There were no complications or physical evidence of sepsis or bowel obstruction during the observation period. Only one dog exhibited decreased body weight, decreasing to 20.4 kg from 22.4 kg after surgery; all of the other dogs exhibited increased body weight. We observed no evidence of peritonitis, intra-abdominal abscess, bleeding, or organ injury on reexploration conducted on day 14 after surgery. Transgastric NOTES sigmoidectomy is a safe operation technique as evaluated in a dog model. The paired magnetic intraluminal device that was used in this study was useful to avoid an abdominal incision for retracting the sigmoid colon.