Feasibility of non-exposed endoscopic wall-inversion surgery with sentinel node basin dissection as a new surgical method for early gastric cancer: a porcine survival study.

Non-exposed endoscopic wall-inversion surgery (NEWS) has been developed as an endoscopic full-thickness resection technique without translumenal communication to avoid intraabdominal infection or tumor seeding. We aimed to investigate the feasibility and safety of NEWS with sentinel node basin dissection (SNBD), which can minimize the area of lymphadenectomy for early gastric cancer (EGC), in 10 porcine survival models. After placing laparoscopic ports and making markings on both the mucosal and serosal sides of a simulated lesion, indocyanine green fluid was endoscopically injected into the submucosa at 4 quadrants around the lesion. An SN basin including the stained SNs was dissected, and a circumferential sero-muscular incision around the lesion and sero-muscular suturing were performed laparoscopically, with the lesion inverted toward the inside of the stomach. Finally, circumferential mucosal incision and transoral retrieval were made endoscopically. In all cases, the lesion was resected in an en bloc fashion, and all pigs survived without adverse events. After 1 week of observation, pigs were sacrificed for macroscopic investigation. The average procedural duration was 170 min (range 130-253 min). Intraoperative perforation occurred in 1 case, which could be safely treated by laparoscopic suturing. The number of dissected SN basins was 1 in 9 cases and 2 in 1 case. Necropsy revealed no signs of severe complication. This animal survival study demonstrated that NEWS with SNBD was safe and feasible. It may provide patients with possibly node-positive EGC a minimally-sized local resection and minimally-ranged lymphadenectomy without the risk of tumor dissemination.