Pure NOTES sigmoid resection in an animal survival model

The potential to use single-site transluminal access to perform major surgical procedures is limited. In the current study, a pure natural orifice transluminal endoscopic surgery (NOTES) technique was developed for sigmoid resection, with combined transgastric and transvaginal access to the abdominal cavity and assisted by colonoscopy.

This experimental study was conducted on a porcine model. Transgastric access was achieved by needle-knife incision and balloon dilation. Colonoscopy was used to maneuver the colon and expose the colic mesentery. Mesocolic dissection close to the bowel was carried out gastroscopically using a coagulating forceps. To prepare the anastomosis, a circular stapler anvil was introduced endoluminally. Subsequently, sigmoid resection was performed using a roticulating linear stapler inserted transvaginally. Bowel extraction was performed by invagination transrectally. After extracorporeal distal linear stapling of the sigmoid, colorectal anastomosis was completed by application of a circular stapling device transrectally. Gastric access closure was achieved using the over-the-scope clipping system (OTSC).

The procedure was successful in all animals, with the operation time ranging from 150 to 270 minutes. The first animal died at postoperative day 5 from peritonitis due to an infected hematoma following spleen injury by an observation trocar. All other animals gained weight postoperatively. Animals were sacrificed after postoperative day 35. The work-up showed complete anastomotic healing and healed gastric closure. The OTSC clip was still in situ in all animals.

The presented study shows that pure NOTES resection and anastomosis of the large bowel are feasible. Intraluminal organ manipulation provided excellent organ exposition and rendered one additional access site unnecessary. Transgastric preparation was shown to be safe and effective.