Comparative evaluation of the efficacy and safety of endoscopic removal of superficial epithelial lesions of the colon using EMR and UEMR: a multicenter study

Objective. To conduct a comparative assessment of the immediate efficacy and safety of endoscopic removal of superficial epithelial lesions of the colon≤25 mm in size using endoscopic mucosal resection (EMR) and underwater endoscopic mucosal resection (UEMR). Material and methods. The study included 109 patients from 5 clinical institutions who underwent removal of 149 superficial epithelial lesions of the rectum and colon. The work was prospective multicenter. Results. Both groups were comparable in all parameters from the side of patients and lesions, however, the size of lesions removed by EMR (n=72) was larger (p=0.004) than those resected by UEMR (n=77), 15 [13; 20] mm and 14 [12; 18] mm, respectively. The complication rates were similar, while direct perforation was observed only in the EMR group, with borderline significance (p=0.052). Prophylactic hemostatic therapy was prescribed significantly more often in the EMR group. The duration of removal was shorter in the UEMR group (p<0.001); 180 [120; 270] versus 240 [180; 400] sec. There were no significant differences in the rates of en bloc removal and R0 (p=0.7 and p=0.5, respectively). Conclusion. Underwater resection has a number of advantages over traditional EMR, such as: theoretical cost-effectiveness (no need to use an injector), higher speed of execution, and probably a lower risk of direct perforation. The rates of en bloc removal and R0 removal for lesions ≤25 mm do not differ. Thus, underwater resection is an effective alternative to traditional EMR for the removal of superficial epithelial lesions ≤25 mm in size. Further studies involving other patient groups and assessing long-term results are needed for subsequent clinical implementation of this technique.