Implanted device for middle cerebral artery occlusion in conscious cats.

A simple implantable device was applied to the left middle cerebral artery of adult cats. One week later the artery was occluded acutely while the animals were conscious. Forced circling and tonic deviation of the head and neck toward the left were noted within seconds of occlusion. A right hemiparesis developed one to two minutes later. Cerebral angiography confirmed the presence of the middle cerebral artery occlusion when the occluding stylet was inserted. Removal of the stylet resulted in reopening of the artery. Light microscopic examination of the brains revealed severe acute ischemic changes in a large left cortical and subcortical area. Partial loss of endothelial lining and thinning of the media were demonstrated in the compressed segment of the middle cerebral artery.