Depth of the cutting plane with underwater and conventional endoscopic mucosal resection: Post‐hoc analysis of a randomized study

Abstract

Background and Aim:A multicenter randomized controlled trial reported a better R0 resection rate for intermediate-sized (10-20 mm) colorectal polyps with underwater endoscopic mucosal resection (UEMR) than conventional endoscopic mucosal resection (CEMR). To clarify whether UEMR removes enough submucosal tissue in the removal of unpredictable invasive cancers, we investigated the cutting plane depth with UEMR versus CEMR. Methods: This was a post-hoc analysis of a randomized controlled trial in which 210 intermediate-sized colorectal polyps were removed in five Japanese hospitals. One pathologist and two gastroenterologists independently reviewed all resected specimens and measured the cutting plane depth. The cutting plane depth was evaluated as (i) maximum depth of submucosal layer and (ii) mean depth of submucosal layer, calculated using a virtual pathology system. Results: We identified 168 appropriate specimens for the evaluation of the cutting plane depth, resected by UEMR (n = 88) and CEMR (n = 80). The median resection depth was not significantly different between UEMR and CEMR specimens, regardless of the measurement method ([i] 1317 vs 1290 μm, P = 0.52; [ii] 619 vs 545 μm, P = 0.32). All specimens in the UEMR and CEMR groups contained substantial submucosa and no muscularis propria. Conclusions: The cutting plane depth with UEMR was comparable with that with CEMR. UEMR can be a viable alternative method that adequately resects the submucosal layer for the histopathological assessment of unpredictable submucosal invasive cancers.

Efficacy and safety of intensive downstaging polypectomy (IDP) for multiple duodenal adenomas in patients with familial adenomatous polyposis: a prospective cohort study

“…In our current strategy, we combined new-generation polypectomy for colorectal polyps, including cold polypectomy and UEMR, which have been reported previously 8 9 26 27 28 . While CSP has a shallow cutting plane and can leave dysplastic tissue in situ when it removes lesions invading deeper than the muscularis mucosa 12 , the cutting plane of UEMR is reportedly as deep as conventional EMR 29 30 . Conversely, CSP reportedly has a low risk of adverse events 16 ; however, UEMR involves the risk of perforation and delayed hemorrhage.…”

“…removes lesions invading deeper than the muscularis mucosa [12], the cutting plane of UEMR is reportedly as deep as conventional EMR [29,30]. Conversely, CSP reportedly has a low risk of adverse events [16]; however, UEMR involves the risk of perforation and delayed hemorrhage.…”

Present situation of minimally invasive surgical treatment for early gastric cancer

“…The results of a multicenter randomized controlled trial indicated that UEMR, with a cutting plane depth comparable to that of CEMR, which can adequately resect the submucosal layer and is a feasible alternative for the histopathological evaluation of unpredictable submucosal invasive tumors[ 16 ].…”

Underwater endoscopic mucosal resection for the diagnosis of metastatic gastric cancer in the descending colon

“…Underwater EMR was first reported by Binmoeller et al in 2012 [1], and we reported its usefulness for resecting colorectal polyps [2] and duodenal tumors. The cutting depth with underwater EMR was comparable to that of conventional EMR [3]. For cases in which pathological diagnosis is difficult by endoscopic biopsy because only nontumor epithelium is obtained, endoscopic ultrasonographyguided fine-needle aspiration may be performed [4]; however, this procedure ▶ Fig.…”