OBJECTIVETo investigate the security and efficacy of a new endoscopic closure method of large defects after endoscopic full-thickness resection (EFTR) double purse-string suture using two endoloops and metallic clips via single-channel endoscopy.

METHODSClinical data of 23 cases with submucosal tumors (SMT) who received endoscopic resection from June 2015 to July 2016 in our National Cancer Center were collected. For gastric and esophageal SMTs or the mucosa layer injured during submucosal tunneling endoscopic resection (STER), double purse-string suture was conducted after EFTR. The key steps of closure were as follows: the endoloop was installed onto the delivery system and inserted into the gastric cavity to the defect location with endoscopy and then opened; the clips were transported into the gastric cavity from the biopsy channel; the endoloop was fixed onto the full thickness of gastric wall along the edge of the defect by clips one by one between the interval of about 5 mm; the endoloop was tightened slowly till the entire circumference of the defect was sutured, thus, one purse-string suture was done; in accordance with the operation above, another endoloop was released, and the second endoloop was fixed at 5-10 mm to the outer edge of the original one, and tied the endoloop gently; this sequence was continued till there was no gap, thus, the double-purse string suture was finished. A total of 23 patients were enrolled in the study, including 18 with gastric tumor and 5 with esophageal tumor, 15 males and 8 females, with the average age of 56 (19 to 76) years.

RESULTSEighteen cases of gastric SMT were successfully treated by endoscopic EFTR and double purse-string suture. The esophageal mucosa layer of all the 5 cases of esophageal SMT, including tumors of 3 cases located in cervical esophagus at 15-20 cm from the fore-tooth, 1 esophageal leiomyoma case complicated with squamous cell carcinoma in situ, and 1 case of mucosal layer injury during submucosal tunneling endoscopic resection (STER), was successfully repaired by using double purse-string suture. The mean maximum diameter of tumor was 2.3 cm, and the average suture time was 22.8 min. Postoperative pathology showed that 13 cases were gastrointestinal stromal tumors (GIST), 7 cases were leiomyoma, 2 cases were neurilemmoma, and 1 case was leiomyoma complicated with early squamous cell carcinoma in situ. No severe complications occurred during or after the operation.

CONCLUSIONSThe double purse-string suture by using metallic clips and endoloops with single channel endoscope is a relatively safe, easy, and reliable technique for repairing large gastric defect after EFTR. For cervical esophageal SMT, or the SMT combined with superficial mucosal lesions, and for the mucosa layer injury during submucosal tunneling endoscopic resection(STER), double purse-string suture is helpful to perform the closure.