Liver function following extended hepatectomy can be accurately predicted using remnant liver volume to body weight ratio.

Abstract

Standardised measurement of remnant liver volume (RLV), where total liver volume (TLV) is calculated from patients' body surface area (RLV-sTLV), has been advocated. Extrapolating the model of living donor liver transplantation, we showed in a pilot study that the simplified RLV/body weight ratio (RLVBWR) was accurate in assessing the functional limit of hepatectomy. The aim of the study was to compare in a prospective series of extended right hepatectomy the predictive value of the RLVBWR and the RLV-sTLV at a cut-off of 0.5% (RLVBWR0.5%) and 20% (RLV-sTLV20%), respectively. We studied the impact of RLVBWR0.5% and of RLV-sTLV20% on three months morbidity and mortality in 74 non-cirrhotic patients operated on for malignant tumours. Of these, 47 patients who were not included in the initial pilot study were enrolled in a prospective validation cohort to reappraise the predictive value of each method. RLVBWR and RLV-sTLV were highly correlated (Pearson correlation coefficient, 0.966). Three months overall and severe morbidity (grade 3b-5) and mortality were significantly increased in groups RLVBWR ≤ 0.5% and RLV-sTLVs ≤ 20% compared to groups >0.5% and >20%, respectively. The sensitivity and specificity in predicting death from liver failure were 100 and 84.1% for RLVBWR0.5% and 60 and 94.2% for RLV-sTLV20%, respectively. Similar results were observed in the validation cohort for the RLVBWR0.5% (lack of statistical power for RLV-sTLV as only 2 patients showed a RLV-sTLV ≤ 20%). The RLVBWR0.5% is a method of assessing the remnant liver that is simple and as reliable as the standardised RLV-sTLV20%.