Assessment of subclinical acute kidney injury after abdominal aortic aneurysm surgery using novel markers: L-FABP and H-FABP.

BACKGROUND One of the most severe complications of repair surgery for abdominal aortic aneurysms (AAA) is acute kidney injury (AKI). Even small rises in serum creatinine are associated with increased mortality. The aim of this study was to assess the dynamics of AKI after elective AAA surgery using novel markers. METHODS The study group consisted of 22 patients with AAA. We measured urinary liver- (u-L-FABP) and heart-type fatty acid-binding proteins (u-H-FABP) before, during and within 3 days after surgery. RESULTS We found an abrupt and significant elevation of both urine FABPs normalized to urinary creatinine; u-L-FABP reached its peak value 2 hours after aortic clamp release {137.79 (38.57-451.79) vs. 9.94 (6.82-12.42) ng/mg baseline value, p<0.05; values are medians (lower-upper quartile)}. The peak value of u-H-FABP was reported 72 hours after aortic clamp release {16.462 (4.182-37.595) vs. 0.141 (0.014-0.927) ng/mg baseline value, p<0.05}. The serum creatinine level did not changed significantly during the investigation period. CONCLUSIONS The significant rise of both u-L-FABP and u-H-FABP after AAA surgery indicates renal proximal and distal tubule injury in this population. Our results suggest that, after AAA surgery, the distal tubules could be more affected than the proximal ones. u-FABPs could serve as sensitive biomarkers of kidney tubular injury and may allow to detect the very early phases of AKI.