RAT MIDDLE CEREBRAL-ARTERY OCCLUSION BY AN INTRALUMINAL THREAD COMPROMISES COLLATERAL BLOOD-FLOW

We compared in Wistar rats collateral blood flow through leptomeningea l anastomoses after middle cerebral artery occlusion using craniotomy ('extravasal occlusion'), which results in a small volume of cerebral infarction, and after intraluminal thread occlusion ('intravasal occlu sion'), which produces a large Volume of cerebral infarction. Simultan eous laser-Doppler flowmetry with two probes placed on the cerebral co rtex was used to measure and compare collateral blood flow. Extravasal occlusion caused a cortical blood flow reduction along a gradient in lateral direction, whereas blood flow reduction after intravasal occlu sion was more uniformly distributed. It is concluded that permanent in travasal occlusion compromises collateral blood flow and therefore may not be a suitable model for measuring the ability of pharmacotherapeu tic agents, if any, to improve collateral blood flow acutely after mid dle cerebral artery occlusion, The two models can be useful for testin g drugs on parenchymal neuroprotective properties. Thereby, the intral uminal technique is preferred because of the possibility to study repe rfusion damage when transient occlusion is applied. (C) 1998 Elsevier Science B.V.