Comparison of the Clinical Outcomes Between Gel Immersion and Underwater Endoscopic Mucosal Resection for Superficial Non-ampullary Duodenal Epithelial Tumors (With Video).

Objective. Gel immersion endoscopic mucosal resection (GIEMR) has recently emerged as a novel technique for superficial non-ampullary duodenal epithelial tumors (SNADETs). However, its clinical advantages over underwater EMR (UEMR) remain unclear. This study compared the short- and long-term outcomes of GIEMR and UEMR for SNADETs.Methods. We retrospectively analyzed patients with SNADETs who underwent UEMR or GIEMR. The R0 resection rate, procedural duration, adverse events, and local recurrence were compared between the groups. Risk factors for non-R0 resection were evaluated using logistic regression analyses.Results. Thirty-two and 49 patients in the UEMR and GIEMR groups, respectively, were included. The R0 resection rate was higher in the GIEMR group than in the UEMR group (GIEMR vs. UEMR; 47.4 vs. 25.7%, p = 0.039). The procedural duration from liquid injection to completion of resection was shorter in the GIEMR group (4 vs. 6 min, p = 0.038). No delayed bleeding or perforation occurred in either group. Kaplan-Meier analysis demonstrated no significant difference in the cumulative local recurrence rate at 3 years between the groups (log-rank test, p = 0.902). Tumor size and UEMR were identified as risk factors for non-R0 resection in the univariate analysis; however, in the multivariate analysis, tumor size was identified as the only independent risk factor for non-R0 resection (odds ratio, 1.172; 95% confidence interval, 1.050-1.309; p = 0.005).Conclusions. GIEMR achieved a higher R0 resection rate and shorter procedural duration than UEMR without increasing adverse events; longer follow-up is warranted.Trial registration. N/A (Only approval of the research protocol by an Institutional Reviewer Board of Fukushima Medical University).