The importance of the origin of vertebral arteries in cerebral ischemia in the rabbit.

The aim of this study was to verify whether experimentally induced total cerebral ischemia in rabbits actually corresponds to total ischemia on the basis of the origin of certain vessels. We observed morphological variations in the origin and course of the arteria vertebralis as one of the vessels supplying the brain with blood. Investigations were carried out on 50 adult New Zealand rabbits. We prepared corrosion casts of the arterial system using Duracryl Dental. We found that in 86% of cases (43 animals) the arteria vertebralis sinistra originated directly from the arteria subclavia sinistra, in 10% of cases (5 animals) it originated from the arcus aortae as an independent branch, and in 4% of cases (2 animals) it arose from the arcus aortae as a common trunk with the arteria scapularis descendens. The arteria vertebralis dextra originated from the arteria subclavia dextra in 98% (49 animals) of cases. In one case we observed two arteria vertebralis dextra with two different origins. Bilateral variability in the origin of the arteria vertebralis was observed in 12% of cases (6 animals). Our results show that ligation of the truncus brachiocephalicus and of the arteria subclavia sinistra do not necessarily cause total cerebral ischemia.