JMIR Publications

ABSTRACT

Background:

Complete mesocolic excision (CME) with central vascular ligation has been proposed to improve lymph-node harvest compared with standard colectomy for colon cancer, though prior reviews report inconsistent heterogeneity and safety findings.

Objective:

This review aims to comprehensively synthesize lymph-node harvest as the primary outcome across the most current available evidence comparing CME with standard colectomy.

Methods:

PubMed, Cochrane CENTRAL, and ScienceDirect were searched to August 2026 per PRISMA 2020 guidelines. Risk of bias was assessed using RoB 2 and ROBINS-I; certainty was rated using GRADE. Continuous outcomes were pooled as mean differences and dichotomous outcomes as risk ratios using random-effects models in Review Manager (RevMan), with heterogeneity assessed via I² and Tau². Studies reporting outcomes in incompatible formats were synthesized narratively alongside pooled estimates.

Results:

Eighteen studies were included. For lymph-node yield, eight studies (n=926 CME, 1,145 comparator) pooled as mean differences showed CME significantly increased yield (MD 6.62, 95% CI [4.40, 8.84]; I²=80%), reduced after confounder-based subgrouping (confound-free MD 8.78, I²=61%; confounded MD 4.14, I²=58%; p=.010); narratively, all remaining studies reporting yield as medians, graded exposure, or unpooled means also favoured CME without exception. For the ≥12-node threshold, four studies showed no overall difference (RR 1.07, 95% CI [0.95, 1.21]; I²=81%), becoming significant after excluding one outlying study (RR 1.13, 95% CI [1.02, 1.24]; I²=51%); two additional studies reported this narratively, one non-significant and one showing the largest individual effect (94.7% vs. 79.1%, p<.001). Node positivity showed no pooled difference across thirteen studies (RR 0.99, 95% CI [0.87, 1.13]; I²=47%), while narratively synthesized studies showed mixed, largely non-significant findings. Postoperative complications showed no difference across eight pooled studies (RR 1.00, 95% CI [0.88, 1.13]; I²=0%), corroborated narratively across nine further studies with only one exception showing higher non-severe morbidity.

Conclusions:

CME consistently increases lymph-node harvest without increasing perioperative complications, though evidence certainty remains low-to-moderate and long-term oncological benefit is unconfirmed.