Patient-level predictors of safety and recurrence after cold versus hot snare resection of large, non-pedunculated colorectal polyps: an individual patient data meta-analysis of four randomised-controlled trials.

BACKGROUND

Cold resection is standard for small colorectal polyps and sessile serrated lesions (SSLs). For large (≥20 mm) non-pedunculated adenomas, it appears safer than hot snare endoscopic mucosal resection (EMR) but is associated with higher rates of residual/recurrent adenoma (RRA).

OBJECTIVE

To pool individual patient data from all available randomised controlled trials (RCTs) and determine whether RRA differs across polyp subgroups.

DESIGN

International, multicentre post hoc individual patient data meta-analysis of four RCTs. Primary outcomes were rates of major adverse events (AE) (AE=deep mural injury III-V/perforation and/or delayed bleeding) and RRA. Subgroup analyses assessed outcomes by location, size, morphology and histology.

RESULTS

1509 polyps in 1423 patients (mean age 66.1 years; mean size 31.3 mm) from 50 centres were included. Major AE occurred in 1.7% of cold versus 5.9% of hot snare resections (OR 0.26; p<0.001). Cold snare was the only factor to reduce major AE in multivariate analysis (OR 0.21; 95% CI 0.07 to 0.60; p=0.004). RRA was higher after cold resection (26.5% vs 12.8%; OR 2.61; p<0.001), with a significant interaction by lesion diameter (p=0.035). By histology, differences were the smallest in SSLs (15.0% vs 8.1%; OR 2.13; p=0.053) and greatest in adenomas with high-grade dysplasia (40.8% vs 18.0%; OR 2.88; p=0.002).

CONCLUSIONS

Cold resection is safer than hot EMR but results in more than double the RRA in all adenoma subgroups, especially those with high-grade dysplasia. It may be appropriate for SSLs between 2 cm and 4 cm and selected cases under anticoagulant/antiplatelet therapy or multimorbid patients, for which further studies are needed.