Impact of mild acute kidney injury (AKI) on outcome after open repair of aortic aneurysms.

Recently, mild AKI has been considered as a risk factor for mortality in different scenarios. We conducted a retrospective analysis of the risk factors for two distinct definitions of AKI after elective repair of aortic aneurysms. Logistic regression was carried out to identify independent risk factors for AKI (defined as $25% or $50% increase in baseline SCr within 48 h after surgery, AKI 25% and AKI 50%, respectively) and for mortality. Of 77 patients studied (mean age 68 +/- 10, 83% male), 57% developed AKI 25% and 33.7% AKI 50%. There were no differences between AKI and control groups regarding comorbidities and diameter of aneurysms. However, AKI patients needed a supra-renal aortic cross-clamping more frequently and were more severely ill. Overall in-hospital mortality was 27.3%, which was markedly higher in those requiring a supra-renal aortic cross-clamping. The risk factors for AKI 25% were supra-renal aortic cross-clamping (odds ratio 5.51, 95% CI 1.05-36.12, p = 0.04) and duration of operation for AKI 25% (OR 6.67, 95% CI 2.23-19.9, p < 0.001). For AKI 50%, in addition to those factors, post-operative use of vasoactive drugs remained as an independent factor (OR 6.13, 95% CI 1.64-22.8, p = 0.005). The risk factors associated with mortality were need of supra-renal aortic cross-clamping (OR 9.6, 95% CI 1.37-67.88, p = 0.02), development of AKI 50% (OR 8.84, 95% CI 1.31-59.39, p = 0.02), baseline GFR lower than 49 mL/min (OR 17.07, 95% CI 2.00-145.23, p = 0.009), and serum glucose > 118 mg/dL in the post-operative period (OR 19.99, 95% CI 2.32-172.28, p = 0.006). An increase of at least 50% in baseline SCr is a common event after surgical repair of aortic aneurysms, particularly when a supra-renal aortic cross-clamping is needed. Along with baseline moderate chronic renal failure, AKI is an independent factor contributing to the high mortality found in this scenario.