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  • Author or Editor: Robert M. Crowell x
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Robert M. Crowell and Yngve Olsson

✓ Anastomosis of the superficial temporal artery (STA) to a middle cerebral artery (MCA) branch was completed about 2 hours after occlusion of the MCA root in 20 dogs. Occlusion of the MCA root without bypass grafting was performed in 11 control animals. All dogs were evaluated clinically. Two days to 3 months (usually 2 weeks) after surgery, STA catheter angiograms were made and the animals sacrificed by perfusion fixation. The brains were evaluated pathologically. Animals with patent or occluded STA-MCA bypass grafts fared better both clinically and pathologically than the controls. Hemorrhagic infarction and blood-brain barrier damage were common in untreated dogs and uncommon in treated animals. STA-MCA bypass grafts rarely led to occlusion of intrinsic collateral blood supply to the brain. The data suggest that prompt STA-MCA branch anastomosis might lead to restoration of neurological function and parenchymal structural integrity in certain patients with acute middle cerebral artery occlusion.

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Robert M. Crowell and Yngve Olsson

✓ Impairment of microvascular filling was demonstrated in relation to focal cerebral ischemia in the monkey. Temporary or sustained middle cerebral artery (MCA) clipping was achieved with a microsurgical technique. Animals were sacrificed by perfusion with a carbon black suspension. Brains were fixed in formalin, and the extent of microvascular carbon filling was estimated grossly and microscopically. In most animals, MCA occlusion of 2 hours to 7 days produced diminished filling in small vessels in the MCA territory of supply. The impairment of filling was most pronounced in the deep subcortical structures but also affected the cortex in some animals. Temporary and sustained occlusion of equal duration produced roughly equivalent areas of abnormal filling. The impairment of vascular filling tended to be more extensive with increasing duration of occlusion. Hypotension during MCA occlusion caused almost total non-filling of the microvasculature in the entire MCA territory. Impaired filling of vascular channels may play a role in the pathogenesis of some clinical cerebrovascular diseases.