Acute kidney injury in patients operated on for type A acute aortic dissection: incidence, risk factors and short-term outcomes

OBJECTIVES: Acute kidney injury (AKI) is a relatively common complication after an operation for type A acute aortic dissection and is indicative of a poor prognosis. We examined the risk factors for and the outcomes of developing AKI in patients being operated on for thoracic aortic diseases. METHODS: We retrospectively analysed 712 patients with acute type A dissection who had deep hypothermic circulatory operations from January 2014 to December 2018, emphasizing those who developed AKI. Logistic regression models were used to identify predisposing factors for the postoperative development of AKI. RESULTS: Among all enrolled patients, 359 (50.4%) had AKI; of these, 133 were diagnosed as stage 1 (18.7%), 126 were stage 2 (17.7%) and 100 were stage 3 (14.0%). Postoperative haemodialysis was required in 111 patients (15.9%). The development of AKI after aortic surgery contributed to the higher mortality rate within 30 days after surgery (P <0.001), longer stay in the intensive care unit (P= 0.01) and longer hospital stay (P < 0.001). Binary logistic regression analysis showed that preoperative cystatin C levels [odds ratio (OR) 2.615, 95% confidence interval (CI) 1.139-6.002; P = 0.023] and postoperative ventilation time (OR 1.019, 95% CI 1.005-1.034; P = 0.009) were independent risk factors for developing AKI. Multiple ordinal logistic regression analyses showed that the preoperative cystatin C level (OR 2.921, 95% CI 1.542-5.540; P= 0.001) was an independent risk factor associated with the severity of AKI. CONCLUSIONS: Our data suggested that the development of AKI after surgery for type A acute aortic dissection was common and associated with an increased short-term mortality rate. The preoperative cystatin C level was identified as an indicator for the occurrence and severity of AKI postoperatively. Furthermore, we discovered that longer postoperative ventilation time was also associated with the development of AKI.