Novel and simple preoperative score predicting complications after liver resection in noncirrhotic patients.

OBJECTIVE: To develop and validate a simple score to predict postoperative complications by severity after liver resection, using readily available preoperative risk factors.

BACKGROUND: Although liver surgery has enjoyed major development with dramatic reduction in mortality rates, the incidence of serious yet nonlethal complications remains high. No scoring system is currently available to identify those patients at higher risk for a complicated course.

METHODS: Complications were prospectively assessed in 615 consecutive noncirrhotic patients undergoing liver resection at the same institution. In randomly selected 60% of the population, multivariate-logistic-regression analysis was used to develop a score to predict severe complications defined as complications grades III, IV, and mortality (grade V) (Clavien-Dindo classification). The score was validated by calibration within the remaining 40% of the patients.

RESULTS: Grades III to V complications occurred in 159 (26%) of the 615 patients after liver resection, 90 (15%) were grade III, 48 (8%) grade IV, and 21 (3%) grade V. Four preoperative parameters were identified as independent predictors including American Society of Anesthesiologists category, transaminases levels (aspartate aminotransferase), extent of liver resection (>3 vs <3 segments), and the need for an additional hepaticojejunostomy or colon resection. A prediction score was calculated on the basis of 60% of the population (369 patients) using the 4 independent predictors ranging from 0 to 10 points. The risk to develop serious postoperative complications was 16% in "low risk" patients (0-2 points), 37% in "intermediate risk" patients (3-5 points) and 60% in "high risk" patients (6-10 points). The predicted mean for absolute risk for grades III to V complications was 27% in the validation population including 40% of the patients (n = 246), whereas the observed risk was 24%. Predicted and observed risks were similar throughout the different risk categories (P = 0.8). The score was significantly associated with hospital and intensive care unit stays. Costs of the entire procedure doubled among the 3 risk groups.

CONCLUSIONS: This novel and simple score accurately predicts postoperative complications and cost in patients undergoing liver resection. This score allows early identification of patients at risk and may impact not only decision making for surgical intervention but also quality assessment and reimbursement.