ACUTE KIDNEY INJURY AFTER AORTIC ROOT REPLACEMENT FOR ASCENDING AORTIC ANEURYSM

Objective: Acute kidney injury (AKI) following cardiac surgery is a vexing problem and a continuing source of morbidity and mortality. Although several studies have attempted to determine its etiology and prophylactic measures, limited data exist after major aortic surgery. The objective of this study was to evaluate the incidence and risk factor for AKI in patients undergoing aortic root replacement (ARR) for ascending aorta aneurysms. Methods: A multi-center observational study of 408 patients undergoing ARR was conducted, focusing on clinical outcome and AKI defined by consensus RIFLE (risk, injury, failure, loss of function, end-stage renal disease) criteria. Results: Mean age was 62±12 years (range: 21–82) with 322 males (79%). Emergent procedures occurred in 31 cases (8%), while 306 and 102 patients underwent isolated ARR (75%) and combined operations (25%). Incidence of postoperative AKI (all RIFLE classes) was 16.9% with 2% of patients requiring renal replacement therapy. Mortality increased with RIFLE class severity of AKI (P<0.001). Independent AKI risk factors were coexistent coronary artery disease (CAD; OR 2.72; 95% CI 1.48–5.01); transfusion requirement (OR 4.8; 95% CI 1.45–15.89) and redo procedures (OR 2.13; 95% CI 1.04–4.39). Age, deep hypothermic circulatory arrest and preoperative creatinine level were not independently associated with AKI. Conclusions: Aortic root replacement for ascending aorta aneurysm can be performed with low rates of postoperative AKI, similarly to other common cardiac surgical procedures. Coexistent CAD transfusion requirement, and redo procedures as independent AKI predictors merit further focused researches enhancing possible preventive AKI strategies.