Table 3.

Definitions of postoperative morbidity and mortality

Event	Criteria
Postoperative mortality	Any reason of death within 90 days after major liver resection.
Postoperative morbidity
Posthepatectomy liver failure	Increasing INR and bilirubin on or after postoperative day 5 plus deviation from regular clinical management (Grade B definition according to the International Study Group of Liver Surgery [ISGLS]) [14].
Cholangitis	Elevation in temperature more than 38.5°C and Leukocytes ≥10*109/L, thought to have a biliary cause, without concomitant evidence of acute cholecystitis, requiring invasive intervention [13].
Hepaticojejunostomy (biliary) leakage	Drainage of fluid with an increased bilirubin level three times greater than the serum level on or after postoperative day three; or the need for interventions as the result of bile collections or biliary peritonitis; or direct visual evidence of defect at anastomoses (definition according to ISGLS) [15].
Intra-abdominal abscess formation	Intra-abdominal fluid collection with positive cultures identified by ultrasonography or computed tomography, associated with persistent fever and elevations of white blood cells [13].
Wound infection	Requiring intervention; otherwise considered as minor complication [13].
Portal vein thrombosis	Conclusive radiologic evidence of thrombosis [13].
Hemorrhage	A drop in haemoglobin level >3 g/dl post-operatively compared with the post-operative baseline level and/or post-operative transfusion of ≥2 units packed red blood cells for a falling haemoglobin and/or the need for radiological intervention (such as embolization) and/or re-laparotomy to stop bleeding (Grade B/C haemorrhage according to ISGLS) [16].
Emergency re-laparotomy	Any (other) reason following major liver resection [13].
Pneumonia	Pulmonary infection with radiological confirmation and requiring antibiotic treatment [13].