A FEASIBILITY STUDY OF A NOVEL ENDOSCOPIC TECHNIQUE FOR DUODENAL TUMORS; PARTIAL SUBMUCOSAL INJECTION UNDERWATER EMR

Aims Under water endoscopic resection (UEMR) has been reported as effective endoscopic treatment for duodenal tumor. However, a notable problem of UEMR for duodenal tumor is that the rate of pathological margin negative is relatively low. Therefore, we proposed a novel technique; partial injection UEMR (PI-UEMR) that we perform partial submucosal injection into a part of the lesion before performing UEMR to visualize clearly the distal side of endoscopic snare and to capture the lesion with sufficient margin. The aim of this study is to evaluate feasibility and safety of PI-UEMR for duodenal tumor.

Methods This is a prospective observational study from tertiary care hospital. We performed PI-UEMR in consecutive patients with duodenal tumor less than 20mm from August to November in 2019. In all cases, we closed the wound with endoclips. And all specimen was stretched and pinned on rubber board for the pathological evaluation. Primary outcome was R0 resection rate that was defined as the en bloc resection rate with free vertical and horizontal margin. Secondary outcomes were mean total procedure time, technical success rate that is defined as the resection rate without remnant lesion, and intra- and postprocedural complication rate.

Results Twelve patients were included in this study. Mean age was 60.1±11.5 years old. Three fourths lesions were located at descending part of duodenum. Median lesion size was 11mm [IQR 8-14mm]. Ten cases were taken endoscopic biopsy in prior hospital and observed biopsy scar. R0 resection rate was 75% (9/12 cases). Mean total procedure time was 19.2±12.3minutes. Technical success rate was 91.7% (11/12 cases). And there was no complication in this study.

Conclusions PI-UEMR might be very useful and safe technique of endoscopic resection for duodenal tumor including relatively large lesions.