Nonexposure laparoscopic and endoscopic cooperative surgery (closed laparoscopic and endoscopic cooperative surgery) for gastric submucosal tumor.

Laparoscopic and endoscopic cooperative surgery (LECS) is increasingly applied for gastric submucosal tumors (SMTs) such as gastrointestinal stromal tumors. However, the conventional LECS procedure has the potential risk that gastric contents and even tumor cells could spread into the abdominal cavity because the gastric wall has to be opened during the resection. To avoid this problem, we have developed a modified LECS procedure named "closed LECS." Ten patients underwent closed LECS for the resection of gastric SMTs. Closed LECS consists of the following steps: endoscopic submucosal layer dissection around the tumor, laparoscopic marking of a resection line on the serosal surface along submucosal dissection line, seromuscular suturing with the marked lesion inverted into the inside of the stomach, endoscopic circumferential seromuscular dissection, and peroral retrieval. In three of the initial five cases, the closed LECS procedure was not completed as planned because of the tumor size and endoscopic inappropriate seromuscular dissection. After modification of the procedure, the entire procedure was successful in all five cases. The mean resected tumor diameter was 24.1 ± 7.6 mm. The mean operation time was 253 ± 45 min. One patient experienced an intra-abdominal abscess potentially related to delayed perforation as a postoperative complication. The closed LECS procedure for gastric SMTs can theoretically be applied without contamination and tumor cell dissemination into the abdominal cavity.