Microvascular anatomy of Heubner's recurrent artery.

The microvascular anatomy of Heubner's recurrent artery (RAH) was studied in 50 human brains (100 hemispheres) using acrylic paint under the operative microscope. The recurrent artery of Heubner was always found as a single vessel in 28 cases (28%) and multiple vessels in 72% (double vessels in 48%, triple in 23% and quadruple in 1%). Altogether 197 RAH were found in 100 hemispheres, averaging 1.97 arteries per hemisphere. In 44 instances, it originated from the proximal part of the A1-segment of the anterior cerebral artery. The diameters of the RAH ranged from 0.4 to 1.5 mm. Their vascular territory was variable. Four groups of distributing branches were found in the RAH: frontal and hypothalamic, olfactory, perforating and sylvian-fissure branches. In 12 hemispheres, anastomoses were found between the perforating branches of the RAH and the middle cerebral artery. In five cases (5%) anastomoses were present between the perforating branches of the MCA and the olfactory branch of the RAH. In one case (1%), an anastomosis was found between two RAH.