Underwater Endoscopic Mucosal Resection Is Associated With Fewer Recurrences and Earlier Curative Resections Compared to Conventional Endoscopic Mucosal Resection for Large Colorectal Polyps

Underwater endoscopic colorectal polyp resection: Feasibility in everyday clinical practice

“…lesions within this size range. However, since UWP and GIP lesions were resected with different electrosurgical generator settings, as also previously reported, 11 the observed differences might be related to the settings themselves, underwater resection, or both.…”

“…for the resection of large lesions. 11 Our study has some strengths. Resection time, when available, was collected prospectively.…”

“…4 Furthermore, there is the risk of dysplastic seeding into deeper wall layers; 23 or the inadvertent injection outside the bowel wall may trigger local peritonitis and infection. 4 UEMR is a safe and effective technique, relatively easy for experienced endoscopists, 4,[8][9][10][11] obviating the aforementioned drawbacks of submucosal injection, and the accidental capture of the circular muscular layer of the colon wall with the resecting snare is less probable. 4 Compared with GIP, a heat-sink effect has been described for UEMR.…”

“…3 Underwater endoscopic mucosal resection (UEMR) is a novel technique: the bowel lumen is filled with water rather than gas eschewing submucosal injection, 4 based on the endoscopic ultrasound (EUS) observation that in the water-filled lumen the mucosa and submucosa float away from the deeper layers. 4,5 Reports attesting to the feasibility, efficacy and safety of UEMR were limited to small series of single and/or tertiary-care referral centres, [5][6][7][8][9][10][11] with limited number of cases 8,9 and with single 5,7,11,12 or supervised operators, 9,10 using caps fitted at the tip of the colonoscope, [5][6][7][8]10,11 pediatric instruments 7,11 or EUS evaluation of the polyps prior to resection. 5,9,10 Minimal data exist from community-based practices where most colonoscopies are performed.…”

Underwater EMR without submucosal injection: Is less more?

“…In a retrospective study comparing UEMR with conventional EMR, UEMR was associated with a higher rate of complete macroscopic resection (98.6% vs 87.1%, P Z .012) and lower rates of adenomatous recurrence for lesions 15 mm. 13 Upon initial follow-up, recurrent adenoma was found in 7.3% of cases after UEMR but in 28.3% after conventional EMR (odds ratio 5.0). Interim results of an international multicenter randomized controlled trial comparing injection-assisted versus underwater EMR for the treatment of 219 large colorectal laterally spreading tumors demonstrated a significantly higher en bloc resection rate for UEMR (51% vs 25%, P Z .001) and significantly fewer additional ablative techniques (11% vs 26%, P Z .006).…”