Gel immersion endoscopic mucosal resection for gastrointestinal neoplasms: a single-center case series study

Aims Underwater endoscopic mucosal resection (UEMR) for gastrointestinal neoplasms has been reported as a simple and useful procedure with higher en bloc and R0 resection rates and a lower recurrence rate than conventional EMR [1]. However, UEMR has several problems, such as poor visual field due to mixing water with residue or blood. Recently, gel immersion endoscopic mucosal resection (GI-EMR) [2], which uses gel instead of water to maintain a good field of view without mixing with residue, has been developed, and this resection method is expected to overcome the above issues of UEMR. However, few studies have evaluated treatment outcomes with GI-EMR, especially in the stomach and colorectum. This study aimed to clarify the efficacy and safety of GI-EMR for gastric and colorectal neoplasms.

Methods The patients who underwent gastric and colorectal GI-EMR at our hospital from April 2021 to December 2023 were retrospectively evaluated for treatment outcomes. The principal indications for GI-EMR are as follows: 1) protruding or flat elevated lesion; 2) size≤20mm in gastric lesions and≤25mm in colorectal lesions. For GI-EMR, the gel was injected via the accessory channel into the stomach or colorectum using a syringe and the BioShield irrigator (U.S. Endoscopy). Then the lesion was carefully snared and resected with a blended cut current (Endocut Q; effect 3, time interval 2, time duration 2).

Results Study 1 (gastric GI-EMR): During the study period, the procedure was performed for 10 lesions in 3 patients. The median lesion size was 11 mm, and the main morphology was 0-I or 0-IIa. The median time for the procedure was 2 minutes, and en bloc resection was achieved in all cases. One lesion had bleeding immediately after resection, but hemostasis was achieved endoscopically. The R0 resection rate was 80% (8 of 10 lesions), and the two lesions that did not achieve R0 resection had unclear horizontal margins. No local recurrence was observed during the follow-up period. Study 2 (colorectal GI-EMR): Four patients (five lesions) underwent colorectal GI-EMR during the study period. The Boston bowel preparation scale at the lesion site was less than 2 points in all cases, and there were residual stools around the lesion that could not be cleared, resulting in a poor visual field under water. The median lesion size was 22 mm, and the morphology was 0-Is, 0-IIa, and 0-IIa+IIc in one, three, and one lesions, respectively. Three out of five lesions were preoperatively diagnosed as sessile serrated lesions, and acetic acid spraying was performed to further define the lesion boundaries. All lesions were resected en bloc. One lesion had immediate bleeding after resection, which could be controlled endoscopically. No perforation or delayed bleeding was observed. No local recurrence was observed at the 1-year follow-up endoscopy.

Conclusions GI-EMR may be a safe and useful treatment for gastrointestinal neoplasms even in a poor visual field under water. However, due to the small sample size, further investigation is required.

Publikationsverlauf

Artikel online veröffentlicht:
27. März 2025

• References

• 1 Nagl S, Ebigbo A, Goelder S. et al. Underwater vs Conventional Endoscopic Mucosal Resection of Large Sessile or Flat Colorectal Polyps: A Prospective Randomized Controlled Trial. Gastroenterology 2021; 161: 1460-1474.e1
• 2 Miura K, Sudo G, Saito M. et al. Gel immersion endoscopic mucosal resection for early gastric cancer near the pyloric ring Endoscopy. 2022