Risk Analysis of Acute Kidney Injury after Cardiac Surgery and Protective Effect by Less Invasive Surgery

Objective: We aimed to determine the incidence and risk of acute kidney injury (AKI) in patients after cardiac surgery, and to assess the effects of less invasive cardiac surgery on the prevention of postoperative AKI.

Methods: We retrospectively analyzed perioperative parameters in patients who underwent cardiac surgery. Risk factors for AKI were determined using univariate and multiple logistic regression models. The incidence of postoperative AKI was also compared between conventional and minimally invasive cardiac surgeries.

Results: Among 126 patients, 36 (28.6%) who developed postoperative AKI stayed significantly longer in the intensive care unit(ICU), required prolonged postoperative ventilation and had a higher frequency of renal replacement therapy. Multivariate analysis revealed cardio-pulmonary bypass (CPB) duration and red blood cell transfusion as independent risk factors for postoperative AKI. The incidence of postoperative AKI was significantly lower after off-pump coronary artery bypass grafting than conventional coronary artery bypass grafting (CABG)(0% versus 11%, p=0.025), and after minimally invasive cardiac surgery compared with conventional valve surgery( 4% versus 44%, p=0.01)

Conclusion: The duration of CPB and red blood cell transfusion were considered independent factors for the development of postoperative AKI. Less invasive cardiac surgeries might protect against postoperative AKI.