A feasibility study comparing gel immersion endoscopic resection and underwater endoscopic mucosal resection for superficial nonampullary duodenal epithelial tumors

Background Although gel immersion endoscopic resection (GIER) is a potential alternative to underwater endoscopic mucosal resection (UEMR) for superficial nonampullary duodenal epithelial tumors (SNADETs), comparisons between the two are currently insufficient. Methods 40 consecutive procedures performed in 35 patients were retrospectively reviewed; the primary outcome was procedure time, and the secondary outcomes were en bloc and R0 resection rates, tumor and specimen size, and adverse events. Results Lesions were divided into GIER (n = 22) and UEMR groups (n = 18). The median (range) procedure time was significantly shorter in the GIER group than in the UEMR group (2.75 [1–3.5] minutes vs. 3 2 3 4 5 6 7 8 9 10 minutes; P = 0.01). The en bloc resection rate was 100 % in the GIER group, but only 83.3 % in the UEMR group. The R0 resection rate was significantly higher in the GIER group than in the UEMR group (95.5 % vs. 66.7 %; P = 0.03). The median specimen size was larger in the GIER group than in the UEMR group (14 mm vs. 7.5 mm; P < 0.001). The tumor size was not significantly different between the groups and no adverse events were observed. Conclusions GIER is efficacious and safe to treat SNADETs, although additional studies are needed.