Dissecting lesions in a culprit artery of a hemorrhagic focus in the basal ganglia: Histopathological analysis by serial sectioning.

In a hypertensive hemorrhagic focus of the basal ganglia, the culprit arteries have been reported to be associated with dissecting lesions, whose topographical relationship to the rupture sites remains to be clarified. Herein we describe multiple dissecting lesions in the culprit artery of hypertensive hemorrhage of the basal ganglia. A 1.0 × 0.8 × 0.8 cm-sized bleeding globe was confirmed at a left lenticulostriate artery and histologically analyzed by serial sectioning. Three independent dissecting lesions were identified in the culprit artery. They were situated near the bifurcations, ranging from 240 to 3200 μm in length. The dissections mainly occurred between the intima and media with disruption of the internal elastic lamina (IEL), forming a fresh thrombus within the false lumen. Two rupture sites causing the cerebral hematoma were confirmed away from the dissecting lesions. One was situated close but not adjacent to the longest dissecting lesion; the other, measuring approximately 150 μm in diameter, was adjacent to the bifurcation of an artery. The histopathological findings suggest that the dissecting lesion resulted from medial detachment following IEL disruption in the process of arterial rupture of the culprit artery. We conclude that this was a secondary manifestation during the rupture rather than a cause of the arterial rupture.