Type of submucosal injection solution for endoscopic resection of large colon polyps – results of a randomized trial

Aims The type of submucosal solution for endoscopic mucosal resection (EMR) of large colorectal polyps remains a matter of debate. Prior studies suggest that a viscous solution facilitates completeness of resection for any GI tract lesion compared to normal saline with a contrast agent (NS), however, data for large colorectal polyps are limited. The aim of the study was to examine safety and efficacy of performing EMR with normal saline (NS) compared to EMR with a viscous solution (VS).

Methods In a multicenter trial, patients with a≥20 mm non-pedunculated colorectal polyp were randomized in a 2x2 design to cold or hot EMR (primary intervention, reported at DDW 2024) and to submucosal injection with VS (either Eleview, hydroxyethyl starch, EverLift, or ORISE) or NS with a contrast agent (secondary intervention). Low dose epinephrine (1:200000 to 1:500000) was added to all injection solutions. The primary outcome was the incidence of severe adverse events (SAE) within 30 days (per patient analysis). Secondary outcomes were technical resection characteristics and recurrence at first surveillance colonoscopy (per polyp analysis). Here we report results of the secondary intervention (there was no interaction between the two interventions).

Results 660 patients were randomized, 557 patients were available for 30-day follow up, and 561 (91.2% of patients eligible for surveillance) completed their first surveillance colonoscopy after a median of 6.2 months. There was no difference in overall SAE (4% in the VS group and 2.4% in the NS group). However, postprocedure bleeding was more frequent following injection with VS (3.0%) compared to NS (0.6%, p=0.037). A reverse but non-significant difference was seen for perforation with 1 perforation in the VS group (0.3%) and 4 perforations in the NS group (1.2%, p=0.216). Polyp recurrence was not different between the groups (22.1% with VS and 19.7% with NS). Subgroup analysis by size, location, morphology, or histology showed not differences. Complete margin treatment reduced recurrence similarly in both groups to 10.9% and 10.3%, respectively. Technical outcomes showed that VS required less amount of injection volume and afforded longer lifting, while NS more often resulted in adequate coloring and facilitated assessment of the resection defect. Overall performance of NS was judged to be more often inadequate or poor compared to VS (9.0 vs 4.5%, p=0.015).

Conclusions In this large randomized trial SAEs and recurrence rates were similar following EMR of large colon polyps using a viscous solution or NS with contrast. However, postprocedure bleeding was more frequent with a viscous solution, while perforation occurred numerically more often with NS. Technical outcomes favor a viscous solution.

ClinicalTrials.gov no: NCT03865537.

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Artikel online veröffentlicht:
27. März 2025