Gel Immersion Endoscopic Submucosal Dissection Using a Scissor‐type Knife for Superficial Non‐ampullary Duodenal Epithelial Tumors

Objectives This study aimed to compare the short‐term therapeutic outcomes between conventional endoscopic submucosal dissection (C‐ESD) and gel immersion ESD (GI‐ESD) for superficial non‐ampullary duodenal epithelial tumors (SNADETs). Methods A retrospective analysis was conducted on patients with SNADETs who underwent C‐ESD or GI‐ESD between June 2016 and May 2024. To reduce proficiency bias, the first 50 cases per endoscopist were excluded. C‐ESD was performed using a scissor‐type knife under CO 2 insufflation, while GI‐ESD was performed using the same knife under gel immersion. Primary outcomes included en bloc and R0 resection rates; secondary outcomes were resection time, adverse events, and inflammatory response. Results Overall, 51 C‐ESD and 49 GI‐ESD procedures were analyzed. Both groups achieved 100% en bloc resection. R0 resection rates were comparable (C‐ESD: 92.6%, GI‐ESD: 90.2%, p = 0.661). Muscle layer exposure was significantly lower in the GI‐ESD group (1.9%) than in the C‐ESD group (16.7%, p = 0.032). The mean white blood cell count was also significantly lower in the GI‐ESD group ( p = 0.038). The incidence of adverse events in the C‐ESD and GI‐ESD groups was 5.6% and 1.9%, respectively ( p = 0.627). However, no cases of perforation or aspiration were observed in the GI‐ESD group. Conclusions GI‐ESD is a safe and effective alternative to conventional ESD for SNADETs, offering comparable resection outcomes and low risk of adverse events with a reduced risk of muscle layer exposure.