Transcolonic endoscopic abdominal exploration: a NOTES survival study in a porcine model

Background: Published reports on NOTES (natural orifice transluminal endoscopic surgery) have thus far been limited to the transgastric method. Objective: The aim of this study was to assess the transcolonic approach as a means of accessing and systematically exploring the abdominal cavity in a survival study design. Design: Six pigs were placed under general anesthesia and were prepped with multiple tap-water enemas, followed by instillation of a cefazolin suspension and a povidone-iodine lavage. Equipment was prepared with a high-level chemical disinfection, and an aseptic technique was used. An incision was made in the anterior colonic wall, and abdominal exploration was performed by using a double-channel endoscope. The incision was subsequently closed with endoscopic clips, endoloops, or a prototype closure device. Patients: Six female Yorkshire pigs that weighed 25 to 30 kg. Results: Stomach, liver, gallbladder, spleen, small bowel, colon, and peritoneal surfaces were identified in all animals in less than 3 minutes. The lower pelvic organs were not consistently visualized. All animals were alive for 14 days without apparent complications. At necropsy, the colonic incision sites were completely closed and appeared well healed. Microscopic inflammatory changes were seen at the closure site in all animals, including microabscesses. Incision-related adhesions were identified in 4 of 6 animals. Conclusions: This study demonstrated the use of a novel transcolonic approach to successfully access and explore the abdominal cavity. In contrast to the transgastric method, a transcolonic approach provides more consistent identification of structures in the upper abdomen and provides better en face orientation and scope stability Therapeutic interventions in the upper abdomen, including organ resection, may be more tenable by using a transcolonic method; however, further studies are needed to address issues of sterility and colonic closure.