Multiparametric Monitoring of Early Pathophysiological Changes in a Porcine Model of Sequential Focal and Global Cerebral Ischemia.

Large animal models of cerebral ischemia have the potential to increase the translational value of stroke research. This study aims to measure early changes of brain tissue oxygen pressure (ptiO 2) and cerebral blood flow (CBF) to characterize a porcine model of sequential middle cerebral artery occlusion (MCAO) and common carotid artery occlusion (CCAO). Eight juvenile German Landrace pigs received unilateral MCAO via a frontotemporal approach under continuous intraparenchymal multiparametric monitoring. Insufficient reduction (i.e., <50% in both ptiO 2 and CBF) was followed by additional bilateral CCAO. Neurodegenerative changes were detected by Fluoro-Jade B (FJB) staining. Only 1 of 8 animals demonstrated a decrease of >50% in both ptiO 2 and CBF after MCAO. Additional CCAO in 7 pigs led to a significant reduction of both ipsilateral and contralateral ptiO 2 (P < 0.01) but not of CBF. There was no difference in ptiO 2 and FJB positive area between hemispheres in this group. Measurement of ptiO 2 correlated negatively with the FJB positive area (P < 0.05). Intraparenchymal multiparametric measurements of acute changes in ptiO 2 and CBF were variable after MCAO. Bilateral CCAO led to a consistent decrease in ptiO 2 and correlated with early degenerative histologic changes, but CBF did not. Real-time procedural ptiO 2 monitoring could provide useful guidance in large animal ischemia models. Feasibility in the context of global cerebral hypoperfusion is demonstrated. [ABSTRACT FROM AUTHOR]