C. V. Ghincea1, M. Aftab1, M. Eldeiry1, G. Roda1, M. Bronsert2, J. D. Pal1, J. C. Cleveland1, D. Fullerton1, T. B. Reece1 1University Of Colorado Denver,Cardiothoracic Surgery,Aurora, CO, USA 2University of Colorado,Aurora, CO, USA
Introduction: Acute kidney injury (AKI) following aortic arch surgery is a frequent complication associated with increased morbidity and mortality. The purpose of this study was to evaluate risk factors for post-operative AKI in patients who underwent open aortic arch surgery utilizing hypothermic circulatory arrest.
Methods: We evaluated 295 consecutive patients undergoing aortic surgery between January 2011 and March 2018. AKI was defined according to KDIGO (Kidney Disease Improving Global Outcomes) Guidelines. Mean age was 58.3 ±13.9 years (range 20-88), 29% (79/295) were female. Mean BMI was 28.7 ±5.9 (range 15.4-52.8) and 33% (96/295) were classified as either urgent or emergent. There were 20% (60/295) reoperations. Chi-squared (and Fisher’s exact when necessary) was used for categorical variables, results expressed as odds ratios. T-test was used for continuous variables, results expressed as means ±standard deviation. Multivariate logistic regression analysis was performed using statistically and clinically significant variables from the univariate analyses.
Results: Of the 295 patients, 93 (32%) developed Stage 1 AKI or greater, 9.2% (27/295) Stage 2 AKI or greater, and 3.7% (11/295) had Stage 3 AKI. In the bivariate analysis, significant predictors of Stage 1 AKI or greater included: history of hypertension (OR 2.78, 95% CI 1.51-5.12, p=0.0008), diabetes (OR 2.36, 95% CI 1.05-5.32, p=0.0337), operative urgency (OR 1.97, 95% CI 1.18-3.29, p=0.0092), cardiopulmonary bypass (CPB) time (p=0.0006), cross clamp time (p=0.0085), circulatory arrest time (p=0.0062), total post-operative transfusions (p=0.0004), and the need for reoperation during hospitalization (OR 3.58, CI 1.80-7.09, p=0.0001). All of these, except cross clamp time, remained significant predictors for Stage 2 AKI or greater. In the multivariate analysis, significant predictors of any AKI were history of hypertension (p=0.0101), CPB time (p=0.0363), and total post-operative transfusions (p=0.0155). Operative urgency, circulatory arrest time, nadir operative bladder temperature, and reoperation during hospitalization were not significant in the multivariate analysis.
Conclusion: Hypertension, CPB time, and total post-operative transfusions significantly predicted AKI in cases undergoing circulatory arrest. Interestingly, circulatory arrest time and nadir temperature were not significantly associated with AKI in the multivariate analysis, but prolonged bypass time was associated with poor renal outcomes. In conclusion, approaches to reducing bypass time should be the focus of decreasing risk for post-operative AKI in hypothermic circulatory arrest cases.
