BACKGROUND AND AIMSAfter endoscopic full-thickness resection (EFTR), defects require a reliable and sustained closure. We present a novel, through-the-scope "bow-tie" (TTS-BT) closing device enabling direct defect closure without scope withdrawal. This preclinical study aimed to evaluate the feasibility and safety of this device for large defect closure after EFTR in a porcine model.METHODSExposed EFTR was performed for virtual lesions >2 cm in the stomach of 12 pigs. Subsequently, TTS-BT closing devices were used for defect closure. Conventional metal clips were used to close any remaining defects. Gastroscopy was performed for 8 weeks to examine the wound sites, and the pigs were subsequently killed. After killing the pigs, the wound healing was histologically verified by hematoxylin and eosin staining. The primary outcome was a successful closure rate; secondary outcomes were complete healing rate, closure time, and incidence of adverse events.RESULTSThe median long and short diameters of perforations were 4.0 cm (range, 3.0-6.0 cm) and 3.0 cm (range, 2.0-4.0 cm), respectively. Defect closure using novel TTS-BT closure devices and conventional metal clips was successfully performed in all pigs. Complete healing was achieved in the defects of 12 pigs. The median closure time was 13 minutes (range, 9-38 minutes). No serious adverse events occurred during the 8-week follow-up.CONCLUSIONSThe novel TTS-BT closure device is feasible and safe for closing large gastric perforations and could be a promising tool for clinical practice.