Reply to Fu et al.

We are grateful for the letter by Fu et al., addressing the application of underwater cap-suction pseudopolyp formation for endoscopic mucosal resection (CAP-UEMR) in flat and challenging colorectal lesions [11].

The authors mention in their letter that CAP-UEMR [22] seems to be a laborious and time-consuming procedure due to the process of prefilling the colonic lumen with water. However, this may not be the case, as underwater endoscopic mucosal resection (UEMR) appears to offer potential advantages in terms of speed compared with classic EMR with submucosal injection, as suggested by a recent randomized controlled trial [33]. Indeed, we believe that CAP-UEMR is a simple technique that could be helpful in some challenging situations. Nevertheless, it should be noted that colonoscope insertion can be more difficult with the distal cap, especially in the narrow sigmoid and flexures. Therefore, our recommendation might be to explore underwater colonoscopy for smooth insertion.

We agree with the authors that hybrid EMR, involving circumferential mucosal incision of the lesion, facilitates snare capture of the target lesion and can provide clear visualization of the lesion margins. Additionally, hybrid EMR could be performed using only one instrument (snare tip for mucosal incision or specialized snares with a knife tip). In expert hands, it could be a viable alternative for en bloc resection of flat colonic lesions

A comparative study evaluating hybrid EMR against CAP-UEMR and other EMR-based techniques or endoscopic submucosal dissection is necessary to enhance our understanding of the most efficacious approach for treating medium-sized, benign, flat, colonic lesions. Meanwhile, it is important to recognize that all these techniques remain valid alternatives, dependent on the operator’s experience and preference.

Publication History

Article published online:
29 May 2024

• References

• 1 Fu M, Zhao L, Jiang X. et al. Endoscopic mucosal resection for challenging colonic mucosal lesions. Endoscopy 2024; 56 DOI: 10.1055/a-2233-0029.
• 2 Uchima H, Calm A, Muñoz-González R. et al. Underwater cap-suction pseudopolyp formation for endoscopic mucosal resection: a simple technique for treating flat, appendiceal orifice or ileocecal valve colorectal lesions. Endoscopy 2023; DOI: 10.1055/a-2115-7797. (PMID: 37348544)
• 3 Sanchez JR, Alvarez-Gonzalez MA, Pellise M. et al. Underwater versus conventional EMR of large nonpedunculated colorectal lesions: a multicenter randomized controlled trial. Gastrointest Endosc 2023; 97: 941-951.e2