Ultrastructural Studies of Cerebral Berry Aneurysms Obtained Operatively

Abstract

Since the first description of cerebral berry aneurysms (RUFUS von EPHESUS, 1549), this pathologically changed tissue of the cerebral vessel-wall has been studied mainly by histological methods. The findings can be summarized as follows:

• Saccular aneurysms of the cerebral arteries occur as a result of a mural defect in the widest sense. These lesions can be caused by congenital abnormalities, inflammation of the vessel-wall, arterio-sclerosis and injury. This means that currently there are two basic views. The first is that they are the result of maldevelopment of the cerebral arteries — the so-called congenital theory. The second is that they are caused by acquired degenerative changes in the arterial wall — the degeneration theory (STEHBENS, 1972). Compared with the great number of histological studies, examinations of cerebral berry aneurysms by electron microscopy are very rare. The first description of the ultrastructure of cerebral arteries (NYSTROEM, 1963) supported the so-called congenital theory, whereas the foll owing studies (LANG and KIDD, 19 65; HASSLER, 1965; STEHBENS, 1975; EBHARDT et al., 1977) support the degeneration theroy. However, systematic studies are not available.