Preclinical Evaluation of the Safety of the Dedicated Gel for Gel Immersion Endoscopy With Gastrointestinal Perforation and Peritoneal Leakage.

Objectives: Gel immersion endoscopic mucosal resection or endoscopic submucosal dissection has been developed as an alternative to saline immersion therapeutic endoscopy. However, in cases of gastrointestinal perforation, gel may leak from the lumen into the peritoneal cavity, and the safety of such events remains unclarified. This study aimed to evaluate the safety of the dedicated gel (Viscoclear, VC) in the event of perforation and peritoneal leakage. Methods: A perforation model was created to compare the colonic burst pressure after VC or saline injection. Acute toxicity was assessed by intraperitoneal VC administration in rats at a maximum dose of 20 mL/kg. Results: The burst pressure was significantly higher for VC injection than for saline. There were no abnormalities indicative of toxicity observed in the general condition or at necropsy after VC administration, and the hematological and biochemical parameters were within normal limits. VC did not promote bacterial growth compared with saline. VC was not cytotoxic and did not cause skin sensitization. Intradermal reactivity tests showed that VC caused negligible irritation that was judged "acceptable". Conclusions: These results suggest that VC is less likely to leak than saline and that, even in the event of a minor leakage into the peritoneal cavity, VC has no acute systemic toxicity and acceptable biocompatibility.