Histologic aspects from ruptured and nonruptured aneurysms.

AbstractWe performed light microscopic examinations on 76 aneurysms from 72 patients (multiple aneurysms in four patients). The slides were stained with HE, Elastica-van-Gieson, Coldner and Prussian blue for iron. Based on morphological findings we were able to differentiate 4 groups of aneurysms. Aneurysmal walls frequently showed complete fibrosis or intimai hyperplasia. One third of the patients had prodromal signs such as headache or neurological deficits before the first subarachnoidal haemorrhage. These aneurysmal walls also had atherosclerotic changes in most cases. Haemodynamic stress as a causal factor seemed to be very important in aneurysmal wall formation. Four patients presented with giant aneurysms with thick fibrotic walls and intimai hyperplasia. 11 aneurysms had never bled. Their walls showed likewise atherosclerotic changes, intimai hyperplasia and sometimes haemosiderin deposits indicating earlier, local’ clinically silent bleeding. In aneurysms after one or multiple bleedings, granuloc...