Underwater hybrid ESD versus conventional ESD for colorectal laterally spreading tumors: a retrospective study

Conventional endoscopic submucosal dissection (C-ESD) is standard for colorectal laterally spreading tumors (LSTs) but is time-consuming. Underwater hybrid ESD (U-Hybrid ESD) is an emerging technique. We compared the efficacy and safety of U-Hybrid ESD versus C-ESD for colorectal LSTs.

This exploratory, single-center retrospective study included 300 patients with LSTs ≥20 mm (U-Hybrid ESD, n = 150; C-ESD, n = 150). Procedure time, postoperative hospital stay, time to resume oral diet, R0 resection rate, and adverse events were compared. Hypothesis-generating stratified analyses by lesion size and pathology were also performed.

After multivariable adjustment, U-Hybrid ESD had significantly shorter procedure time (adjusted mean 21.29 vs. 31.99 min, adjusted mean difference -10.70, P < 0.001), shorter hospital stay (2.38 vs. 2.61 days, P = 0.008), and earlier oral diet (25.28 vs. 28.32 h, P = 0.004). The R0 resection rate showed a numerical difference between groups (96.67% vs. 100%), which did not reach statistical significance on Fisher's exact test (P = 0.060). Adverse events did not differ significantly (5.33% vs. 9.33%, P = 0.318).

In this exploratory analysis, U-Hybrid ESD was associated with shorter procedure time and modest improvements in postoperative recovery metrics, without a significant increase in complications. These hypothesis-generating findings suggest that U-Hybrid ESD may offer efficiency benefits for selected lesions, but the potential trend toward lower R0 rates for large or high-grade lesions warrants caution and prospective validation before any definitive size-based recommendations can be made.