Impact of retrograde cerebral perfusion on S100β release during hypothermic circulatory arrest for thoracic aortic surgery

Abstract

Introduction. The efficacy of retrograde cerebral perfusion (RCP) as an adjunct for brain protection during hypothermic circulatory arrest (HCA) remains controversial. The purpose of this study was to use S100β (a serum marker for cerebral injury) to evaluate the impact of RCP during thoracic aortic surgery Methods. Thirty-seven adult patients undergoing thoracic aortic surgery using HCA were evaluated. RCP was used during HCA in 25 patients (68%). Blood was collected preoperatively, 30 minutes after cardiopulmonary bypass (CPB), and 24 hours postoperatively; S100β levels were measured using a standard immunoradiometric assay. Results. Patients in the RCP and non-RCP groups had similar CPB times (125 ± 47 vs 135 ± 20 minutes, p = 0.376), HCA times (34 ± 13 vs 35 ± 14 minutes, p = 0.80), and baseline S100β levels (0.09 ± 0.12 vs 0.09 ± 0.08 μg/L, p = 0.827). S100β levels were significantly elevated 30 minutes after CPB and 24 hours postoperatively in both groups. RCP did not reduce S100β levels 30 minutes after CPB (3.76 ± 2.28 μg/L with RCP vs 4.22 ± 2.79 μg/L without RCP, p = 0.599) or at 24 hours postoperatively (0.83 ± 1.69 μg/L with RCP vs 0.53 ± 0.38 μg/L without RCP, p = 0.413). Conclusions. RCP does not significantly affect S100β release during HCA in patients undergoing thoracic aortic surgery. Using serum S100β as a marker for brain injury, RCP does not provide improved cerebral protection over HCA alone.