Cerebral embolization during cardiac surgery: Impact of aortic atheroma burden

Background. Aortic atheromatous disease is known to be associated with an increased risk of perioperative stroke in the setting of cardiac surgery. In this study, we sought to determine the relationship between cerebral microemboli and aortic atheroma burden in patients undergoing cardiac surgery. Methods. Transoesophageal echocardiographic images of the ascending, arch and descending aorta were evaluated in 128 patients to determine the aortic atheroma burden. Transcranial Doppler (TCD) of the right middle cerebral artery was performed in order to measure cerebral embolic load during surgery. Using multivariate linear regression, the numbers of emboli were compared with the atheroma burden. Results. After controlling for age, cardiopulmonary bypass time and the number of bypass grafts, cerebral emboli were significantly associated with atheroma in the ascending aorta (R²=0.11, P=0.02) and aortic arch (P=0.013). However, there was no association between emboli and descending aortic atheroma burden (R²=0.05, P=0.20). Conclusions. We demonstrate a positive relationship between TCD-detected cerebral emboli and the atheromatous burden of the ascending aorta and aortic arch. Previously demonstrated associations between TCD-detectable cerebral emboli and adverse cerebral outcome may be related to the presence of significant aortic atheromatous disease.