Impact of en bloc resection on long-term outcomes after endoscopic mucosal resection: a matched cohort study

Abstract

Background and Aims: Residual or recurrent adenoma (RRA) is the major limitation of piecemeal EMR (p-EMR) for large colonic laterally spreading lesions (LSLs) 20 mm. En bloc EMR (e-EMR) has been shown to achieve low rates of RRA but specific procedural and long-term outcomes are unknown. Our aim was to compare long-term outcomes of size-matched LSLs stratified by whether they were resected e-EMR or p-EMR.Methods: Data from a prospective tertiary referral multicenter cohort of large LSLs referred for EMR over a 10-year period were analyzed. Outcomes were compared between sized-matched LSLs (20-25 mm) resected by p-EMR or e-EMR.Results: Five hundred seventy LSLs met the inclusion criteria of which 259 (45.4%) were resected by e-EMR. The risk of major deep mural injury (DMI) was significantly higher in the e-EMR group (3.5% vs 1.0%, P Z .05), whereas rates of other intraprocedural adverse events did not differ significantly. Five of 9 (56%) LSLs, with endoscopic features of submucosal invasion (SMI), resected by e-EMR were saved from surgery. RRA at first surveillance was lower in the e-EMR group (2.0% vs 5.7%, P Z .04), but this difference was negated at subsequent surveillance. Rates of surgical referral were not significantly different between the groups at either surveillance interval. Conclusion:When comparing e-EMR against p-EMR for lesions 25 mm in size of similar morphology in a large prospective multicenter cohort, e-EMR offered no additional advantage for predicted-benign LSLs. However, it was associated with an increased risk of major DMI. Thus, en bloc resection techniques should be reserved for lesions suspicious for invasive disease.

Impact of surgical versus endoscopic management of complex nonmalignant polyps in a colorectal cancer screening program

“…Therefore, organized population-based CRC screening programs have been established worldwide. Many of these programs use fecal immuno-chemical testing (FIT) as a primary test, with referral to colonoscopy as a follow-up [3].While most of the detected polyps in screening programs can be removed endoscopically, some complex nonmalignant polyps are referred for surgical resection [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. This is due to their large size, flat shape, location, or suspected submucosal invasion, which is a sign of malignant behavior.…”

Cold versus hot endoscopic mucosal resection for large sessile colon polyps: a cost-effectiveness analysis

“…Finally, we assumed that all hot EMRs were performed in a piecemeal fashion. While we acknowledge that the use of hot EMR facilitates en bloc resection in roughly 13 % of LSCPs ≥ 20 mm [19,24], recent data suggest that there is no significant difference in the rates of long-term recurrence between piecemeal and en bloc EMR, therefore this did not impact our model [25]. Furthermore, the most recent European Society of Gastrointestinal Endoscopy (ESGE) clinical guidelines recommend limiting en bloc EMR to lesions < 20 mm outside the rectum [26] because of its association with higher rates of deep mural injury.…”

Response

“…We thank Wang et al 1 for their letter discussing our article. 2 We would like to address their points as follows: 1. This study was designed as a comparative analysis of size-matched lesions (20-25 mm).…”

“…This study was designed as a comparative analysis of size-matched lesions (20-25 mm). 2 This size criterion was selected because of the inability to reliably and safely achieve complete en bloc EMR (e-EMR) for laterally spreading lesions (LSLs) >25 mm. 3,4…”