Efficacy of gel immersion endoscopic submucosal dissection for colorectal lesions

Endoscopic submucosal dissection (ESD) for colorectal lesions has become widely accepted but remains technically demanding, with perforation risk related to luminal distension and suboptimal visualization. Gel immersion ESD (GI-ESD) may offer mechanistic advantages over conventional CO ² -insufflation ESD (C-ESD), including reduced colonic distension, improved visibility/depth perception, buoyancy-assisted dissection stability, and heat-sink protection. We hypothesized that these features would improve short-term safety and procedure stability.

In this single-center retrospective study, 426 consecutive colorectal ESD cases (from January 2022 to December 2024) were analyzed. C-ESD was performed from January 2022 to March 2024; GI-ESD using Viscoclear (Otsuka Pharmaceutical Factory, Tokushima, Japan) from April to December 2024. After excluding non-epithelial lesions, 392 patients were included, including interrupted procedures. The primary outcome was adverse events (perforation, delayed bleeding). Secondary outcomes were en bloc and R0 resection rates, procedure time, and postoperative inflammatory response.

Of 392 patients, 293 underwent C-ESD and 99 underwent GI-ESD were analyzed. En-bloc and R0 resection rates were comparable between GI-ESD and C-ESD (97.0% vs. 99.9%, P = 0.16, 90.6% vs. 91.4%, P = 0.35). The perforation rate was significantly lower in GI-ESD (0% vs. 4.1%, P = 0.04). Postoperative fever (≥ 37.6°C; 4.2% vs. 12.7%, P = 0.02) and median CRP elevation (0.33 mg/dl vs. 0.42 mg/dl, P < 0.01) were also significantly reduced in GI-ESD; however, incidence of post-endoscopic submucosal dissection electrocoagulation syndrome (PECS) was not significantly different between groups.

GI-ESD achieved curative outcomes comparable to C-ESD while reducing perforation risk; PECS remained comparable between groups.