Predicting complications in hepatic resection for colorectal liver metastasis: the lymphocyte-to-monocyte ratio

Colorectal cancer is one of the most common malignancies worldwide; whilst approximately 20% of patients have hepatic disease at presentation. Hepatic resection remains the gold standard of care; however, it is associated with significant morbidity. We sought to establish whether the lymphocyte-to-monocyte ratio (LMR) could help predict post-operative complications, thus improving patient outcomes.

We performed a retrospective cohort study of patients undergoing hepatic resection at a single centre. Baseline demographics and complications within 30 days following surgery were recorded. White blood cell counts and C-reactive protein (CRP) were recorded pre-operatively, and until post-operative day 7.

A total of 188 operations were included. About 47.3% of resections had a complicated recovery, of which 31.46% were major. The median LMR was 1.29 across the cohort, 1.60 for uncomplicated procedures, 1.14 for those with complications and 0.85 in major complications. For detecting major complications versus an uncomplicated recovery, median LMR was the best parameter (area under the curve 0.78), whilst it was the only parameter to accurately predict such complications within 48 hours of surgery (area under the curve 0.72 on day 1). It was consistently the most accurate parameter at detecting uncomplicated versus complicated recovery, minor versus major complications, and major complications versus an uncomplicated recovery, at numerous timepoints over the post-operative period.

The LMR appears better at predicting complications following hepatic resection for colorectal liver metastases, as opposed to conventionally measured parameters.