Should We Mark the Margins Before EMR?

Should We Mark the Margins Before EMR?

Douglas K. Rex, MD, MASGE, reviewing Yang D, et al. Gastrointest Endosc 2021 Nov 30.

One approach sometimes used in endoscopic mucosal resection (EMR) to improve complete resection is to use cautery to mark the normal tissue at the margins of the lesion and then extend the resection to the marks. This helps to ensure complete resection.

In a single-center study with historical controls, 210 patients, each of whom had a lesion with a median size of 30 mm, underwent either EMR with margin marking (EMR-MM; n=74) or conventional EMR (n=136). The recurrence rates at 6 months were 8% with EMR-MM and 29% with conventional EMR. There was no increased rate of adverse events with EMR-MM. On multivariable analysis, both EMR-MM (odds ratio [OR], 0.20) and increased polyp size (OR, 2.81) predicted recurrence.

Douglas K. Rex, MD, FASGE


There are obvious limitations regarding the use of historical controls, and there were differences in techniques between the groups other than the use of margin marking. To the extent margin marking works, it would support the concept derived from recent studies of thermal ablation of the margin, ie, that most recurrences after piecemeal EMR using electrocautery originate from the defect margin. Personally, I find that after submucosal injection with a contrast agent, the actual margins of colorectal adenomas are easy to delineate. Furthermore, the absolute rates of recurrence in recent large trials of thermal ablation (2%-5%) are lower than that in this study of margin marking. Finally, we don’t know that performing the marking plus extending the resection out to the markings is any more efficient than thermal edge ablation. To the extent that this technique merits consideration as a rival to thermal ablation, a prospective randomized trial would be needed.

Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.


Yang D, Draganov PV, King W, et al. Margin marking before colorectal endoscopic mucosal resection and its impact on neoplasia recurrence (with video). Gastrointest Endosc 2021 Nov 30. (Epub ahead of print) (

Related Posts

Scroll to Top