A risk model to predict 90-day mortality among patients undergoing hepatic resection

Abstract

Background: Reliable criteria to predict mortality after hepatectomy remain poorly defined. We sought to identify factors associated with 90-day mortality, as well as validate the "50-50" and peak bilirubin of >7 mg/dL prediction rules for mortality after liver resection. In addition, we propose a novel integer-based score for 90-day mortality using a large cohort of patients.

Study design: Data from 2,056 patients who underwent liver resection at 2 major hepatobiliary centers between 1990 and 2011 were identified. Perioperative laboratory data, as well as surgical and postoperative details, were analyzed to identify factors associated with liver-related 90-day death.

Results: Indications for liver resection included colorectal metastasis (39%), hepatocellular carcinoma (19%), benign mass (17%), or noncolorectal metastasis (14%). Most patients had normal underlying liver parenchyma (71%) and resection involved ≥3 segments (36%). Overall morbidity and mortality were 19% and 2%, respectively. Only 1 patient fulfilled the 50-50 criteria; this patient survived and was discharged on day 8. Twenty patients had a peak bilirubin concentration >7 mg/dL and 5 died within 90 days; the sensitivity and specificity of the >7-mg/dL rule were 25% and 99.3%, respectively, but overall accuracy was poor (area under the curve 0.574). Factors associated with 90-day mortality included international normalized ratio (odds ratio = 11.87), bilirubin (odds ratio = 1.16), and serum creatinine (odds ratio = 1.87) on postoperative day 3, as well as grade of postoperative complications (odds ratio = 5.08; all p < 0.05). Integer values were assigned to each factor to develop a model that predicted 90-day mortality (area under the curve 0.89). A score of ≥11 points had a sensitivity and specificity of 83.3% and 98.8%, respectively.

Conclusions: The 50-50 and bilirubin >7-mg/dL rules were not accurate in predicting 90-day mortality. Rather, a composite integer-based risk score based on postoperative day 3 international normalized ratio, bilirubin, creatinine, and complication grade more accurately predicted 90-day mortality after hepatectomy.