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Updated: Oct 25, 2025

Underwater Endoscopic Injection Sclerotherapy for Gastroesophageal Varices
Published on: August 1, 2025
Efficacy of partial injection underwater endoscopic mucosal resection for superficial duodenal epithelial tumor:
Yusaku Takatori1, Motohiko Kato1, Teppei Masunaga1
1Division of Research and Development for Minimally Invasive Treatment, Cancer Center, Keio University School of Medicine, Tokyo, Japan.
Background And Aim:
Underwater endoscopic mucosal resection (UEMR) has been reported as effective endoscopic treatment for superficial duodenal epithelial tumors (SDETs). However, it has been reported that a notable problem of UEMR for SDETs is that en bloc resection rate is relatively low. Therefore, we proposed a novel technique to improve en bloc resection rate: UEMR combining partial submucosal injection (PI-UEMR). The aim of this study is to evaluate efficacy and safety of PI-UEMR for SDETs by comparing to UEMR.
Methods:
This is a retrospective observational study in a single center. The patients who underwent UEMR or PI-UEMR from June 2010 to August 2020 were included in this study. Eligible patients were selected from included patients in a 1:1 ratio using propensity score matching. The clinical outcomes of endoscopic resection (procedure time, en bloc resection rate, complication rate [immediate perforation, delayed bleeding, delayed perforation]), and histopathological diagnosis (adenoma/cancer) were compared between each group.
Results:
Two hundred and twenty-eight patients were included in this study. Of included patients, 47 patients were selected in each group by propensity score matching. There were no statistical differences in procedure time (11 ± 1.2 min vs. 9 ± 1.2 min, P = 0.30), complication rate (immediate perforation [0% vs. 2%, P = 0.12], delayed bleeding [0% vs. 2%, P = 0.12], and no delayed perforation) and histopathological diagnosis (adenoma; 100% vs. 96%, P = 0.14) in each group. However, en bloc resection rate of PI-UEMR was significantly higher than UEMR (96% vs. 83%, P < 0.05).
Conclusion:
Partial submucosal injection UEMR might be superior procedure for en bloc resection in SDETs compare to UEMR.
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