Unilateral antegrade cerebral perfusion through the right axillary artery provides uniform flow distribution to both hemispheres of the brain - A magnetic resonance and histopathological study in pigs

Background-Bilateral antegrade cerebral perfusion (ACP) has decreased in po pularity over the past decade because of its complexity and the risk of cer ebral embolism. We used magnetic resonance (MR) perfusion imaging to assess flow distribution in both hemispheres of the brain during unilateral ACP t hrough the right carotid artery via a cannula placed in the right axillary artery in conjunction with hypothermic circulatory arrest. Methods and Results-Twelve pigs were randomly exposed to 120 minutes of eit her bilateral ACP through both carotid arteries (n = 6) or unilateral ACP t hrough the right axillary artery (n = 6) at pressures of 60 to 65 mm Hg at 15 degrees C, followed by 60 minutes of cardiopulmonary bypass at 37 degree s C. MR perfusion images were acquired every 30 minutes before, during, and after ACP. The brain was perfusion fixed for histopathology. During initia l normothermic cardiopulmonary bypass, MR perfusion imaging showed a unifor m distribution of flow in the brain. In both the bilateral and unilateral A CP groups, the same pattern was maintained, with an increase in regional ce rebral blood volume during ACP and reperfusion. The changes in regional cer ebral blood volume and mean transit time were similar in both hemispheres d uring and after unilateral ACP. No difference was observed between the 2 gr oups. Histopathology showed normal morphology in an regions of the brain in both groups. Conclusions-Both bilateral ACP and unilateral ACP provide uniform blood dis tribution to both hemispheres of the brain and preserve normal morphology o f the neurons after prolonged hypothermic circulatory arrest.