[Branches of the perforating portions of the internal carotid arteries and their commissural anastomoses].

By means of injection methods allowing microscopic preparation of vessels 0.015 mm and less in diameter the author examined 25 block-specimens of the base of the skull which contained the left and right cavernous parts of the internal carotid arteries and structures adjacent to them. The specimens were obtained in cases in which death was caused by the disease not associated with pathological conditions of the central nervous system. Arteries arising from the cavernous part of the internal carotid artery are described. The author determined the existence of a system of permanent commissural anastomoses between the cavernous parts of the left and right internal carotid arteries which is formed by the branches of the dorsal meningeal, inferior hypophyseal, and capsular arteries (McConnell arteries). The importance of the system in the diagnosis and treatment of pathological processes of parasinus and parasellar localization, particularly arteriosinus malformations of this region, is pointed out.