Primary dissecting aneurysm of the extracranial part of the internal carotid and vertebral arteries

Abstract

Primary dissecting aneurysms of the extracranial part of the internal carotid and vertebral arteries were found in 3 subjects above 50 years. In 2, the aneurysm was localized to the cervical part of the internal carotid artery and, in 1, to both vertebral arteries. In the latter case, a dissecting aneurysm in each renal artery was found. In 2 of the cases the dissecting aneurysm was seen incidentally at necropsy and in 1 by X-ray during life. Degeneration of the media with damage to the smooth muscle tissue and elastic tissue was seen in all 3 cases. Degeneration of the media was conceived as a cause of the dissecting aneurysm and was probably a sign of aging. The clinical picture varied with the degree of ischemia produced by the vascular lesions in the respective fields of supply of the arteries. Rupture of vasa vasorum due to hypertension and ischemia of the vascular wall produced by incipient shock and toxic factors were possibly the direct cause of the hemorrhage.