Endoscopic submucosal dissection effective for colorectal polyp regardless of lesion size

Endoscopic submucosal dissection (ESD) seems to be a more effective approach to colorectal polyps than endoscopic mucosal resection (EMR), with the former resulting in better surgical outcomes and lower recurrence rates, according to a recent Singapore meta-analysis.

“Evidence from this meta-analysis suggests that with appropriate training, ESD is preferred over EMR as the first-line therapy for resection of colorectal polyps, without restricting to lesions greater than 20 mm and those with high suspicion of submucosal invasion,” the researchers said.

“Our overall findings are consistent with previous meta-analyses showing ESD is associated with higher rate of en bloc and complete resection, and lower recurrence compared to EMR, but at the cost of increased procedural time, need for additional surgical operations, and perforation risk,” they added.

A total of 21 studies were retrieved from the databases of Embase and Medline, providing 281,344 colorectal polyps available for analysis. Pooled analysis revealed that ESD led to a significantly higher rate of en bloc resection (risk ratio [RR], 1.837, 95 percent confidence interval [CI], 1.464–2.305; p<0.001) than EMR. [World J Gastroenterol 2021;27:3925-3939]

Complete resection was likewise significantly better with ESD (RR, 1.504, 95 percent CI, 1.041–2.174; p<0.03), while positive lateral margin involvement was less likely (RR, 0.292, 95 percent CI, 0.089–0.995; p=0.042). Rate of polyp recurrence was also significantly suppressed after ESD vs EMR (RR, 0.269, 95 percent CI, 0.112–0.648; p=0.003).

On the other hand, ESD required a longer procedural time than EMR (RR, 72.709, 95 percent CI, 54.487–90.931; p<0.001) and needed more additional surgical operations (RR, 3.139, 95 percent CI, 1.360–7.243; p=0.007).

In terms of complications, ESD led to a significantly higher risk of perforation than EMR (RR, 7.597, 95 percent CI, 4.281–13.479; p<0.001), but no differences were detected for bleeding risk (RR, 1.277, 95 percent CI, 0.896–1.820; p=0.175).

The principal meta-analysis findings were robust to subgroup analysis by region, as well as to sensitivity analysis by lesion size. In particular, the rates of en bloc resection and polyp recurrence were comparable after stratifying lesions into ≥20 vs <20 mm subgroups, suggesting that ESD remained effective even without size restrictions.

On the other hand, meta-regression analysis revealed that right colonic polyps were at a higher risk of perforation under ESD (β, 7.731, 95 percent CI, 4.965–10.497; p<0.001).

“As such, training should ensure endoscopists achieve procedural proficiency in left sided lesions before proceeding to attempt right sided lesions,” the researchers said.

“The inclusion of 21 studies with a total of 281,344 polyps based on our search strategy and inclusion criteria represents the most extensive meta-analysis on this issue,” they added, noting however that there are still no randomized controlled trials that directly compare the performance of EMR and ESD.

“This highlights the need for a randomized study to better understand the efficacy and safety of these techniques in the management of colorectal polyps,” they said.