[Analysis of 53 ruptured middle cerebral artery aneurysms].

In spite of a recent remarkable progress in operative results of ruptured middle cerebral artery aneurysms, a mortality rate of 2-8% appears to be unavoidable. In the present study, 53 ruptured MCA aneurysms were retrospectively analyzed to determine causative factors of unfortunate outcome (fair, poor and dead). Surgical results of 53 ruptured MCA aneurysms are shown in Table 1, where the outcome was unfortunate in 7 cases (17%). Intracerebral hematoma was responsible for 4 cases, two of which were fatal and postoperative vasospasm for 3 cases. There were 13 cases with intracerebral hematomas (25%) ranging from 21 mm to 68 mm in diameter. Although hematomas less than 40 mm in diameter localized in temporal or frontal subcortical areas and yielded no neurological deficits, those more than 60mm extended to the caudate nucleus or thalamus through the internal capsule and led to deep coma (Table 2, Fig. 1). Intracerebral hematoma with the diameter between 50 to 60 mm seems to be critical in regard to postoperative outcome. Repeated rupture caused intracerebral hematoma (50%) more frequently than single rupture (21%) and aneurysm with intracerebral hematoma was liable to bleed (27%), resulting in acute deterioration of neurological conditions by marked enlargement of the hematoma (Fig. 2). Accordingly it is essential for the cases with intracerebral hematoma to prevent rerupture. Subarachnoid hemorrhage and symptomatic vasospasm were observed less frequently in hematoma group than in non-hematoma group. However, prophylactic treatment of vasospasm is important even in the cases with intracerebral hematoma since more than half of them suffer from relatively thicker subarachnoid clot.