New methods
Clinical endoscopy
“Underwater” EMR without submucosal injection for large sessile colorectal polyps (with video)

https://doi.org/10.1016/j.gie.2011.12.022Get rights and content

Background

Submucosal injection is widely performed before EMR of large sessile colorectal polyps to facilitate resection and decrease perforation risk. We developed a novel method of water immersion (“underwater”) EMR (UEMR) that eliminates submucosal injection.

Objective

To evaluate the feasibility and outcomes of UEMR without submucosal injection for large sessile colorectal polyps.

Design

Prospective, observational study.

Setting

Single, tertiary-care referral center.

Intervention

The standardized EMR technique involves full water immersion for the entire procedure and piecemeal resection with a 15-mm “duck bill” snare.

Main Outcome Measurements

Complete resection, bleeding, perforation, postpolypectomy syndrome, residual or recurrence adenoma.

Results

Sixty patients with 62 large sessile colorectal polyps underwent UEMR. The mean/median polyp size was 34/30 mm, and the mean/median resection time was 21/18 minutes. Histology revealed the following: tubular adenoma (n = 22), tubulovillous adenoma (n = 19), villous adenoma (n = 4), serrated adenoma (n = 11), and high-grade dysplasia/carcinoma in situ (n = 6). The mean/median interval until a follow-up colonoscopy in 54 patients (90%) was 20.4/15.2 weeks. One of 54 patients (2%) had an adenoma smaller than 5 mm outside of the postresection scar, consistent with a residual lesion missed on index UEMR.

Complications

There was no perforation or postpolypectomy syndrome. Delayed bleeding occurred in 3 patients and was managed conservatively.

Limitations

Limited follow-up; single-center, single-endoscopist, uncontrolled study.

Conclusions

The underwater resection technique enables complete removal of large sessile colorectal polyps without submucosal injection. The technique was safe in a large patient cohort, and the early recurrence rate appears low. Use of a water interface for UEMR has potential advantages that deserve further study.

Section snippets

Patients

UEMR was performed on consecutive patients referred for endoscopic treatment of large sessile colorectal polyps starting in June 2010. The inclusion criteria for the cohort were (1) sessile polyp defined as a lesion with a thickness less than half of the maximum width; (2) benign adenoma on previous biopsy; (3) benign appearance on high-definition colonoscopy without stigmata of malignancy (ulceration, bleeding, induration, Kudo pit pattern V)5; and (4) size equal to or greater than 2 cm.6

Procedures

Results

Over 11 months, 60 consecutive patients referred for resection of large sessile colorectal polyps were treated with UEMR (Table 1). Complete resection was successful in all patients without early complication. Piecemeal resected specimens floated away from the immediate site of resection, but remained within segmental reach of the colonoscope and were easily retrieved, usually by direct suctioning through the working channel. Only a minority of postresection defects (27%) were amenable to clip

Discussion

With the standard colonic EMR technique, the lumen is insufflated with air, which has the drawback of distention and subsequent thinning of the colon wall. The rationale for submucosal injection is to decrease the risks of accidental ensnaring of the muscularis propria and transmural thermal injury that can lead to perforation.

We describe a new technique of water-immersion EMR. This was inspired by the observation during EUS that, when filled with water, the colonic muscularis propria remains

Cited by (0)

DISCLOSURE: All authors disclosed no financial relationships relevant to this publication.

If you would like to chat with an author of this article, you may contact Dr Binmoeller at [email protected].

View full text
Copyright © 2012 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.