Background: For intermediate-sized (10–20 mm) superficial non-ampullary duodenal epithelial tumors (SNADETs), various endoscopic resection (ER) techniques are available, including conventional endoscopic mucosal resection (EMR), underwater EMR (UEMR), and endoscopic submucosal dissection (ESD). However, the optimal method remains uncertain. Summary: We conducted a systematic review of studies published from January 2013 to August 2023 using PubMed and the Japan Medical Abstracts Society database. Eligible studies reported ER outcomes for SNADETs of ≤20 mm. Data were extracted from 14 cohort studies (3 multicenter of lesions 10-20 mm in size and 11 single-center of lesions less than 20 mm), including en bloc and R0 resection rates, delayed bleeding, intraoperative and delayed perforation, and recurrence. In the multicenter studies, the pooled en bloc resection rates for EMR, UEMR, and ESD of intermediate-sized SNADETs were 82.7%, 74.8%, and 94.6%, respectively. The corresponding R0 resection rates were 54.2%, 50.6%, and 80.9%. Delayed bleeding rates were similar across methods (3.3% for EMR, 3.2% for UEMR, and 5.4% for ESD). However, intraoperative and delayed perforation were more frequent with ESD (7.9% and 3.0%) than with EMR (1.1% and 0.3%) and UEMR (0.0% and 0.0%). Single-center studies showed consistent trends, with ESD achieving higher resection rates but also showing greater variability in adverse events. Recurrence rates were about 5% for EMR and UEMR, with no recurrences reported after ESD. Key messages: While ESD provides superior resection quality, EMR and UEMR offer favorable outcomes with fewer adverse events. Given their safety and efficacy profiles, EMR and UEMR should be considered appropriate first-line treatment options for intermediate-sized SNADETs.
Yamasaki et al. (2026) studied this question.