Acute kidney injury (AKI) is a severe complication after liver resection and is associated with morbidity and mortality. The incidence of postoperative AKI is significantly higher in elderly patients, especially in those with comorbidities.

There is currently limited evidence on the incidence and associations of postoperative AKI in elderly patients following liver resection.

This study will evaluate the incidence and associations of AKI in elderly patients after liver resection and its impact on postoperative mortality.

The occurrence of postoperative AKI is independently associated with increased morbidity and mortality. Advanced age reduces renal autoregulatory capacity due to physiological and functional changes, thus render the elderly to suffer postoperative AKI and probably the consequent chronic kidney disease.

Although elderly patients account for approximately 25% of surgical procedures, the incidence and associations of AKI in this group of patients are rarely understood.

Thus, it is essential to identify those patients at high risk to develop postoperative AKI to optimize perioperative prevention and protection strategies.

This study is a retrospective cohort study, aim to access risk factors of postoperative AKI and its association with outcomes. The investigators will develop and validate a predictive model for postoperative AKI.

The principal clinical outcome of the study is postoperative AKI, defined as an absolute increase in serum creatinine of 0.3 mg/dL within 48 hours or a 1.5-fold increase from preoperative baseline within seven days after surgery, according to the Kidney Disease: Improving Global Outcomes (KDIGO) criterion.

Inclusion Criteria:

• Elderly patients aged ≥65 years
• Benign and malignant liver diseases

Exclusion Criteria:

• Emergency operation
• Liver transplantation

Elderly patients (aged ≥ 65 years) with benign and malignant liver diseases of the Chinese PLA General Hospital HPB (Hepato-Pancreato-Biliary) Center undergoing liver resection from 2012-2019