Effect of extracranial-intracranial bypass and pentobarbital on acute stroke in dogs.

Ninety-three mongrel dogs underwent intracranial carotid and middle cerebral artery occlusions. They were then randomized into four groups: 1) the untreated control group (no surgical or medical therapy) showed significant neurological deficit, 16% mortality, and 17% mean hemisphere infarction; 2) in the bypass group (superficial temporal to middle cerebral artery (STA-MCA) anastomosis completed within 3 hours of occlusion), neurological deficit was diminished, mortality was 7%, and mean infarction 5.66%; 3) in the pentobarbital group (single dose of pentobarbital, 35 mg/kg administered intravenously 30 minutes after occlusion), neurological deficit was essentially the same as in the previous group, there was no mortality, and mean infarction was 5.52%; and 4) in the pentabarbital/bypass group (pentabarbital dose plus STA-MCA bypass), neurological deficit was slightly lower than in previous treatment groups, there was no mortality , and mean hemisphere infarction was 1.78%. Extracranial-intracranial bypass produced an immediate 31.6% increase in regional cortical blood flow. The combination of pentobarbital postocclusive therapy and early extracranial-intracranial bypass beneficial synergism.