Neutrophil gelatinase-associated lipocalin and acute kidney injury in endovascular aneurysm repair or open aortic repair: a pilot study

Introduction: Acute kidney injury (AKI) occurs frequently after abdominal aortic surgery and there is currently no effective marker able to detect early onset. The aim of this study is to evaluate the ability of neutrophil gelatinase-associated lipocalin (NGAL) to early identify the development of acute renal damage in patients undergoing endovascular aneurysm repair (EVAR) or open aortic repair (OAR). Materials and methods: Serial samples of blood and urine were obtained from 25 patients undergoing both EVAR and OAR. Seven male subjects with AKI and 18 subjects with no-AKI (17 males, 1 female) were included in the study. We determined concentrations of serum creatinine (sCr) and urinary, serum and whole blood NGAL (uNGAL, sNGAL, bNGAL) collected at baseline, and after 4 and 18 hours. AKI was defined according to the RIFLE criteria (risk, injury, failure, loss of kidney function, and end-stage kidney disease): increase by 50% in sCr or reduction of at least 25% of estimated glomerular filtration rate (eGFR) from baseline. Results: Seven patients developed AKI in the stage Risk. There was no significant difference in sNGAL concentrations in the AKI group as compared to no-AKI group. However, the uNGAL/uCreatinine ratio and bNGAL concentrations were significantly higher after 18 hours in the AKI group (no-AKI 1.69 (0.91 - 2.47) vs AKI 3.2 (2.08 - 5.92) ng/mg for uNGAL/uCreatinine ratio, P = 0.036; and no-AKI 83 (59 - 131) vs AKI 164 (126 – 263) ng/mL for bNGAL, P = 0.029). Conclusions: Our results suggest that uNGAL, sNGAL and bNGAL, after abdominal aortic surgery, are not suitable as early biomarkers of AKI.