Direct incision versus submucosal tunneling as a method of creating transgastric accesses for natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy: Randomized controlled trial

Aim: The optimal approach for creating accesses for transgastric peritoneoscopy is still uncertain. The present study aims to assess the feasibility of carrying out transgastric submucosal tunnel (SMT) peritoneoscopy and to determine whether this approach improves or restricts access to various sectors within the peritoneal cavity. Methods: This was a randomized comparative study carried out in an in-vivo survival porcine model. Sixty-six beads in six swine were visualized and touched via gastrotomies created by either direct incision (DI) or SMT. The influence of the type of gastrotomy on improving or restricting access to particular sites within the peritoneal cavity for natural orifice transluminal endoscopic surgery (NOTES) peritoneoscopy was compared. The main outcome measurements were localization score of beads, overall procedural time, morbidities and mortalities. Results: A significantly higher mean (SD) localization score was observed in peritoneoscopies carried out in the DI group (P < 0.001). Both the visualization and the touching scores were significantly better with the DI technique, and the overall yield of NOTES peritoneoscopy with DI and SMT were 72.73% and 60.6%, respectively (P = 0.043). Significantly more beads that were not touched in the SMT group were located in the sub-phrenic area (P = 0.013). The overall procedural time was significantly shorter in the DI group (P = 0.004). No major morbidities or mortalities occurred in any procedures. Conclusions: SMT resulted in lower visualization and touching scores for transgastric NOTES peritoneoscopy. Alternate methods to improve the diagnostic yield to the sub-phrenic area are required.