On factors related to growth and rupture of intracranial aneurysms

Summary

The incidence of calcification and of fatty plaques was investigated in 70 autopsy cases with 85 intracranial aneurysms. Seventy aneurysms had ruptured. Stereomicroscopic microradiographic and histopathological methods were utilized. Anomalies of the circle of Willis were observed in 55%, corresponding to what is usually found in previous aneurysm series. Fatty plaques and/or calcifications were observed in the aorta and carotid arteries in 60% and were more widely generalized in 24% of the cases. Several of the patients were relatively young. Fatty infiltration was found in the walls of all aneurysms. Adjacent to the plaques the walls of the aneurysms were thin and frequently bulging. Empty thin outpouchings were also found. The sites of rupture were related to the outpouchings. The fatty plaques were considered to be prestages of calcifications. Calcification was found in the walls of 25 aneurysms. In older patients fatty atheromatous plaques and calcifications were larger and situated nearer the necks of the aneurysms; in younger patients they were nearer the domes, often at the widest diameter of the aneurysms. The sites of rupture were close to the fatty plaques of calcifications and generally distal to them. The importance of using a microscope at operation is stressed.

Zusammenfassung

Die Häufigkeit von Verkalkungen und Fettplaques wurde an 70 Autopsiefällen mit 85 intrakraniellen Aneurysmen untersucht. 70 Aneurysmen waren rupturiert. Es wurden stereomikroskopische, mikroradiographische und histopathologische Methoden verwendet. Anomalien des Circulus arteriosus Willisii fanden sich in 55%, was den Befunden früherer Aneurysmaserien entspricht. Fettplaques und/oder Verkalkungen der Aorta und Carotiden fanden sich in 60% und waren weitgehend generalisiert in 24% der Fälle. Einige Patienten waren verhältnismäßig jung. Fettige Infiltration fand sich in der Wand aller Aneurysmen. Nahe den Plaques war die Aneurysmenwand dünn und oft vorgewölbt. Leere, dünne Ausbuchtungen waren nachweisbar. Die Fettplaques werden als Vorstufen der Verkalkungen angesehen. Verkalkungen fanden sich in der Wand von 25 Aneurysmen. Bei älteren Patienten waren die atheromatösen Lipidplaques und Verkalkungen größer und näher dem Aneurysmenhals; bei jüngeren Patienten waren sie näher der Kuppe und oft im weitesten Durchmesser des Aneurysmas. Die Rupturstellen waren nahe den Fettplaques oder Verkalkungen und meist distal davon. Die Bedeutung der Verwendung eines Mikroskops bei der Operation wird hervorgehoben.