Comparing underwater endoscopic submucosal dissection and conventional endoscopic submucosal dissection for large laterally spreading tumor: a randomized controlled trial

Abstract

Background and AimsColorectal endoscopic submucosal dissection (ESD) is challenging despite its usefulness. Underwater ESD (UESD) provides better traction and a clearer view of the submucosal layer than conventional ESD (CESD). This study compared the efficiency of UESD and CESD for large (20–50 mm) laterally spreading tumor (LST). MethodsPreplanned sample size was calculated from our previous experience. As a results, 28 patients were required to UESD group or CESD group, respectively. The primary outcome was total procedure time while the secondary outcome was dissection speed. ResultsFifty-six patients were enrolled and a total of 28 patients were assigned to each group. The mean size of LST was 31.6 mm and 31.3 mm in the UESD and CESD group, respectively. Fibrosis was observed in 67.9% and 60.7% patients in the UESD and CESD group. Total procedure time (mean [SD]) for the UESD group was significantly shorter than that for the CESD group, respectively (49.5 minutes [20.3] vs 75.7 minutes [36.1]; mean difference, -26.2 minutes; 95% CI, -42.0 to -10.5). Dissection speed of the UESD group was significantly faster than that of the CESD group (21.9 mm2/min [6.9] vs 15.2 mm2/min [7.3]; mean difference, 6.7 mm2/minutes; 95% CI, 2.8–10.4). There was no difference between groups in the R0 resection rate or en bloc resection rate. No perforations were observed in either group. ConclusionsUESD was superior to CESD in total procedure time and dissection speed. UESD can be recommended as the preferred method for the resection of large LST.