Comparison of urine and serum neutrophil gelatinase-associated lipocalin after open and endovascular thoraco-abdominal aortic surgery and their meaning as indicators of acute kidney injury.

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL) has been described as a potential biomarker of acute kidney injury (AKI) in different settings, but its behaviour under influence of open and endovascular repair of thoraco-abdominal aortic aneurysms (TAAA) has not been assessed yet. In this study, the course of NGAL was observed and differences of serum- (sNGAL) and urine-NGAL (uNGAL) levels following TAAA repair, especially with regard to AKI, were evaluated.

PATIENTS AND METHODS: In this retrospective single centre study, 52 patients (mean age 64.5 years, [43-85 years]), including 39 (75 %) men, were enrolled (2014-2015, 13.2 months mean follow-up). Levels of sNGAL and uNGAL were measured perioperatively for 48 hours on intensive care unit. Twenty-three patients were treated by endovascular and 29 by open TAAA-repair.

RESULTS: Logistic regression revealed an increase in NGAL (sNGAL p = 0.0263, uNGAL p = 0.0080) corresponding with an increase in serum creatinine within the first 48 hours. Fourteen patients (26.9 %) developed AKI and 11 (21.1 %) required dialysis. The course of NGAL differed significantly (uNGAL p < .0001, sNGAL p = 0.0002) between patients suffering from AKI requiring dialysis and patients without AKI. The predictive power of uNGAL was three times higher than that of sNGAL (estimate of the regression slope 0.1382 vs. 0.0460). No significant difference between patients undergoing open or endovascular TAAA repair regarding the perioperative course of sNGAL and uNGAL was observed.

CONCLUSION: serum-NGAL and urine-NGAL correlate with serum creatinine levels and AKI requiring dialysis. Furthermore, the postoperative course of sNGAL and uNGAL after open and endovascular TAAA repair is not significantly different. Taken together, the results indicate that uNGAL and, to a lesser extent, sNGAL could be considered biomarkers for early detection of perioperative AKI after open and endovascular TAAA surgery.