Acute cerebral revascularization after regional cerebral ischemia in the dog

Abstract

The efficacy of cerebral revascularization by anastomosis of the superficial temporal artery (STA) to the middle cerebral artery (MCA), performed 4 and 24 h after a regional MCA infarction had been produced by combined occlusion of the MCA and internal carotid artery, was tested in 12 dogs. To control possible intercurrent variables, 7 other dogs remained untreated and 5 had a sham operation. Clinical and pathological changes were recorded and analyzed. An incidence of 85% infarction was obtained in the untreated control group. The severity of the clinical deficits and pathological changes for the anastomosed groups were greater than those seen in the untreated control group. The extent of the infarction was significantly greater (P < 0.05) in the anastomosed groups than in the sham-operated and control groups. Hemorrhagic infarcts occurred in most of the dogs in the anastomosed groups, but were not present in either control group (P < 0.05). The 2 dogs in the 4-h and 1 in the 24-h group improved more than any control dog, but the difference was not statistically significant (P > 0.05). In 2 dogs with occluded anastomosis the clinical deficits and the pathological changes were less than those seen in animals with patent anastomosis. The severity of the pathological and clinical changes correlated well with the reestablishment of flow in the MCA territory. Cerebral revascularization at 4 and 24 h following a regional MCA infarct in the dog is followed by an exacerbation of the microcirculatory obstruction, cerebral edema and infarction. Based on improvement noted in 3 animals, revascularization under special conditions could benefit some cases following acute cerebral infarction.