Location of SBI
Based on the evaluation of SBI location, a high number of lesions were
localized in the right hemisphere. We speculated the possible causes of
SBI in the right hemisphere, which were as follows: First, MICS is
performed while the patients are in the left lateral decubitus position
at our institution, and this might have made it easier for debris and
air to reach the right-dominant vasculature area. Floyed et al. reported
a similar tendency on MRI after median sternotomy 6.
In the reports of Knipp et al. 11 and Barbut16, the percentage of embolic lesions in the posterior
cerebral circulation was high. However, the actual cause of lesion
localization in these studies was not identified. Second, the
brachiocephalic artery, which is the first artery from the heart other
than the coronary artery, is the final point of blood flow in retrograde
perfusion. Therefore, air and debris in the heart are most likely to
burst out during the time at which cardiac beating begins after the
release of the aortic clamp, and the brachiocephalic artery becomes the
boundary between retrograde perfusion and cardiac output. Then, the air
and debris can flow to the brachiocephalic artery.