Abstract
Five autopsied cases of dissecting aneurysms with spontaneous subarachnoid hemorrhage (SAH) of the intracranial vertebro-basilar artery are reported, and the literature is reviewed to investigate the pathological characteristics and pathogenesis of this lesion. The location and pathological features of the aneurysms differed in each presented case. Subadventitial hemorrhage associated with SAH, multiple noncontiguous intramural hemorrhages, and new vessels in and around the arterial wall were noteworthy findings in our series. All 20 reported autopsided cases of the vertebrobasilar artery have a dissection between the media and adventitia with a rupture site in the thin adventitia. Seventeen had disruption of the entire arterial wall, but the remaining three had no apparent luminal connection. The clinico-pathological features of this disease are various. Based on the pathological investigations of these reported cases, the pathogenesis of this lesion is discussed. Intramural hemorrhage associated with dissection without luminal connection should not be disregarded as a causative factor.
