Middle cerebral artery occlusion in Macaca fascicularis:: acute and chronic stroke evolution

Background An intravascular stroke model designed for magnetic resonance imaging was developed in Macaca fascicularis (M. fascicularis) to characterize serial stroke lesion evolution. This model produces a range of stroke lesion sizes which closely mimics human stroke evolution. This paper describes the care of animals undergoing this stroke procedure, the range of outcomes we experienced and the cause of mortality in this model. Methods Anesthesia was induced with atropine and ketamine and maintained with isoflurane or propofol. Non-invasive blood pressure, oxygen saturation, heart rate, respiration rate, temperature and end tidal CO2 were monitored continuously. The stroke was created by occluding a distal branch of the middle cerebral artery. During catheter placement animals were heparinized and vasospasm was minimized using verapamil. Results Anesthetic induction and maintenance were smooth. Animals with small strokes showed very rapid recovery, were able to ambulate and self-feed within 2 hours of recovery. Animals with strokes of >= 4% of the hemispheric volume required lengthy observation during recovery and parenteral nutrition. Large strokes resulted in significant brain edema, herniation and brainstem compression. Conclusions Intracerebral hemorrhage and or subarachnoid hemorrhage coupled with a stroke of any size was acutely fatal. In the absence of an effective acute stroke therapy, the spectrum of outcomes seen in our primate model is very similar to that observed in human stroke patients.