Urinary Liver-Type Fatty Acid Binding Protein as a Postoperative Marker of Acute Kidney Injury in Patients Undergoing EndovascularAortic Aneurysm Repair

Objective: To evaluate the role of urinary liver-type fatty acid binding protein (L-FABP) in early detection of acute kidney injury (AKI) after endovascular aortic aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). Design: Prospective, observational, multicenter study. Setting: Four university hospitals from January 2024 to June 2024. Participants: Fifty-nine hospitalized patients with AAA. Interventions: Patients undergoing EVAR were included. Demographic data, comorbidities, and renal function data were recorded at baseline and after intervention. L-FABP data were collected at baseline and at 6 hours and 24 hours after surgery. Measurements and Main Results: The cohort had a mean age of 70.2 ± 7.3 years and was predominantly male (84.7%). Positive L-FABP results were observed in 24.1% of patients at 6 hours post-EVAR and in 23.7% at 24 hours post-EVAR. A positive L-FABP status at both time points was significantly associated with elevated postoperative serum creatinine (SCr) and reduced estimated glomerular filtration rate (eGFR) (p ≤ 0.015), reduced urine output (p = 0.009 and p < 0.001), and shorter hospital length of stay (LOS) (p = 0.004 and p = 0.013). Multivariable logistic regression analysis fully confirmed these associations. Predictive models incorporating L-FABP achieved high accuracy for identifying patients with reduced diuresis (up to 86.1%). Additionally, L-FABP at 6 hours and 24 hours predicted LOS, whereas SCr and eGFR values did not. Conclusion: Urinary L-FABP is emerging as a sensitive biomarker for AKI in patients undergoing EVAR.