Comparative Study of Three Modalities of Endoluminal Approaches for Closure of Gastrotomy after NOTES

Abstract

Purpose: Reliable closure of transgastric NOTES access with simple technique is greatly needed. The aims of this study were (i) to systematically compare effectiveness and reliability of three endoluminal approaches for gastrotomy closure to open surgical hand suturing and (ii) to re-validate the role of omentoplasty in closure of balloon-created gastric defects. Methods: Standard gastrotomy accesses were created by endoscopic needleknife incision and balloon dilation. After completing exploratory peritoneoscopy, the democratic dogs were randomly assigned to four groups: the gastric defects in group A were closed by Endoclip; group B used omentoplasty; group C used the over-the-scope clip system (OTSC); and group D served as a control with hand suturing via open surgery. In non-survival experiments, leak-proof tests were performed. Other 20 dogs after closure were survived two weeks. On necropsy, the healing in gastrotomy site, clip retention, intraperitoneal infections, tissue adhesions, and injury of adjacent organs were evaluated, and the gastrotomy site was excised for histological assessment of wound healing. Results: Successful gastrotomy closures were performed in all cases. Mean procedure duration was shorter for omentoplasty closure (6.0±1.1 min) and OTSC group (6.5±1.3 min) compared to Endoclip group (34.9±12.4 min), (P<0.001, no statistical difference between omentoplasty group and OTSC group). Leakproof test revealed the burst pressure in OTSC group was (81.5±10.6mmHg) comparable to that of hand suture group, and higher than that of omentoplasty group (43.0±11.5 mmHg) or Endoclip group (36.3±12.5 mmHg) (P=0.002, no statistical difference between omentoplasty group and OTSC group). 2 dogs in Endoclip group died 1 week after closure due to leakage of closure and peritoneal abscesses, and the remaining 18 animals survived for two weeks with no signs of illness. With exception of the two dogs died in Endoclip group, all gastrotomies healed satisfactorily without leakage and no significant intraperitoneal infections or adhesions were detected. Complete healing of gastrotomy site achieved in all animals of OTSC and omentoplasty group, and the apparent incorporation of omentum flap into gastric wall was easily identified in omentoplasty group. Conclusion: Both omentoplasty and OTSC can reliably make closure of gastrotomy accesses for peroral NOTES with comparable results to surgical hand suturing. Omentoplasty in gastrotomy site, despite of a relative low burst pressure, can effectively seal the transgastric opening with technical simplicity and facilitate the wound healing process through histological remodeling into gastric wall.