Morphologic aspects of the influence of experimental microembolism on cerebral microcirculation

1. A precision method to study in three dimensions the influence of the angio-architecture on microembolism of the canine brain is described. 2. Of 14 dogs embolized, the brains of two, one hypertensive, the other with middle cerebral artery ligation, were chosen for study. The arterial hypertension and middle cerebral artery ligation did not significantly influence the results. 3. Larger emboli (diameter 60–80μ) in meningeal arteries when abundant produced extensive ischemia with infarction of both cerebral cortex and underlying white matter. 4. In the canine brain, an isolated embolus (diameter 55–60μ) in a penetrating cortical artery will produce a single cortical infarct. 5. The meningeal arterial plexus, with the anastomosing arterial loops serve to prevent infarction in the cerebral cortex. Under adverse hemodynamic conditions, the efficiency of the meningeal arterial plexus to prevent infarction is influenced by structural variations in diameter and in the pattern of the vessels.