- Underwater endoscopic mucosal resection (UEMR) led to a greater frequency of R0 resection of 10-20-mm sessile colorectal lesions compared with conventional endoscopic mucosal resection (CEMR), with no significant difference in adverse events or procedure time.
Why this matters
- The study is the first randomized controlled trial to compare UEMR and CEMR.
- 211 patients with 214 polyps, at 5 institutions in Japan, were randomly assigned to UEMR or CEMR.
- Funding: None.
- The UEMR group had a higher R0 resection rate (69% vs 50%; P=.011) and a higher en bloc resection rate (89% vs 75%; P=.007).
- There was no significant difference in median procedure times (165 vs 175 seconds; P=.629).
- There were no incidents of intraprocedural hemorrhage requiring transfusion, interventional radiology, or surgery.
- 2 patients in the CEMR group and 3 in the UEMR group experienced delayed bleeding from the treatment site within 48 hours of the procedure.
- There were no significant differences in adverse events between the 2 groups.
- A subset analysis showed that UEMR performed best for lesions 15 mm or higher (P=.016).
- Recurrence rate was not evaluated.
- Endoscopists were not blinded.