Anastomoses among the perforating arteries of the brain. Microanatomy and clinical significance.

Abstract

Anastomoses among the perforating arteries were examined in 50 human brains using injection technique with India ink and gelation, or methylmethacrylate. Anastomoses were not found among the perforators of the internal carotid artery and the thalamogeniculate branches. Anastomotic channels involving perforating branches of the anterior choroidal, middle cerebral, and anterior cerebral arteries were noted in 1% of the cases. Vascular connections of the premamillary arteries were observed in 30% of the brains. They varied from 60 to 280 microns) in diameter, and from 0.3 to 3.6 (mean 1.5 mm) in length. Anastomoses among the interpeduncular (thalamoperforating) branches of the posterior cerebral artery were present in 79% of the cases. They ranged from 80 to 400 microns (mean 146 microns) in caliber, and from 0.9 to 6.1 mm (mean 3.3 mm) in length. Since anastomoses among the interpeduncular and the premamillary arteries are much more frequent than those among other perforators, thalamic, subthalamic, and midbrain's infarctions seem to be less frequent than capsular and ganglionic ischemic lesions.