Unilateral cerebral perfusion: right versus left.

Objectives: Unilateral cerebral perfusion for brain protection is gaining increasing interest, although the pathways of collateral flow as well as many aspects of the surgical strategy regarding optimal perfusion pressure, flow and temperature remain unclear. This study evaluates the differences between right- and left-sided unilateral cerebral perfusion, if any, especially with regard to neurovascular monitoring findings and clinical outcome.

Methods: Between January 2005 and April 2008, 200 consecutive patients underwent elective aortic arch surgery at our facility. One-hundred patients were selected for left-sided unilateral cerebral perfusion supplying the brain through the left common carotid artery and another 100 patients for unilateral cerebral perfusion supplying the brain through the right-sided carotid and vertebral arteries. Arterial return of the cardiopulmonary bypass and the unilateral cerebral perfusion were performed in all patients via cannulation of a corresponding carotid artery using a side graft.

Results: Arch repair was performed under mild hypothermic circulatory arrest with a rectal temperature of 30.1 + or - 1.8 degrees C and 31.6 + or - 1.6 degrees C in the left- and right-sided cerebral perfusion, respectively. The duration of circulatory arrest with unilateral cerebral perfusion was identical for both groups (17.2 + or - 2 min). Brain perfusion was performed through the arterial line at a blood temperature of 28 degrees C and a flow rate of 0.9 + or - 0.2 l min(-1) on the left and 1.5 + or - 0.3 l min(-1) on the right. The flow velocities in the median cerebral artery contralateral to the side being perfused revealed no differences between the groups. There was no 30-day mortality. Two patients (one in each group) with severe calcification of the aortic valve suffered minor strokes.

Conclusion: Unilateral cerebral perfusion under mild hypothermia is an efficient method of cerebral protection. The advantage of the right-sided perfusion in which two brain-supplying arteries are perfused could not be verified.