Impact of contrast exposure from computed tomography angiography on acute kidney injury after neonatal cardiopulmonary bypass surgery

Abstract

Objective: Acute kidney injury (AKI) is a frequent complication after cardiopulmonary bypass (CBP) for cardiac surgery in neonates. It is unclear if exposure to computed tomography angiography (CTA) in the preoperative period increases the risk of AKI. We hypothesized a short interval between CTA and CPB surgery would be associated with higher rates of AKI in infants.

Design: In this single center retrospective review of patients between 2012 and 2015, neonates less than one month old were analyzed if they had CTA prior to cardiac surgery with CPB. Baseline, demographic, fluid balance, and laboratory data was analyzed. AKI was staged according to KDIGO criteria.

Results: Fifty-six neonates were analyzed. AKI developed in 42 (75%) of patients; severe AKI (KDIGO stages 2 and 3) occurred in 18 (32%). Patient characteristics were similar at baseline and at time of CTA between those with and without severe AKI. Patients with severe AKI had longer CPB time, lower postoperative urine output, higher peak serum creatinine, and longer hospital length of stay. When considering intervals between CTA and CPB surgery ≤1 day (n = 19), ≤3 days (n = 28), and >3 days (n = 28); there was no difference in AKI incidence nor postoperative outcomes among these three interval cohorts.

Conclusion: Routine exposure to CTA and CPB surgery in close succession does not appear to increase the risk of AKI after neonatal cardiac surgery. Though other risks need to be weighed (eg, sedation, intubation, radiation exposure), this result may enable more liberal utilization of CTA for preoperative surgical planning of congenital heart operations in patients with unclear or complex anatomy.

Keywords: acute kidney injury; congenital heart disease; congenital heart surgery.