Comparison between intrasylvian and intracerebral hematoma associated with ruptured middle cerebral artery aneurysms: clinical implications, technical considerations, and outcome evaluation

Background: Subarachnoid hemorrhage (SAH) due to a middle cerebral artery (MCA) aneurysms rupture is often associated with intracerebral (ICH) or intrasylvian hematomas (ISH). Materials and methods: We reviewed 163 patients with ruptured MCA aneurysms associated with pure SAH or SAH+ICH/ISH. Patients were first dichotomized according to the presence of a hematoma (ICH/ISH). Then, we performed a subgroup analysis comparing ICH versus ISH in order to explore their relationship with the most relevant demographic, clinical, and angioarchitectural features. Results: Overall, 85 patients (52%) had a pure SAH, whereas 78 (48%) presented an associated ICH/ISH. No significant differences were observed in demographics and angioarchitectural features between the two groups, but Fisher grading and Hunt-Hess score were higher in patients with hematomas. A good outcome was observed in a higher percentage of patients with pure SAH compared with the others (76% Vs 44%), although mortality rates were comparable. Age, Hunt-Hess and treatment-related complications were the main outcome predictors at multivariate analysis. Patients with ICH appeared clinically worse than those with ISH. We also found that older age, higher Hunt-Hess, larger aneurysms, decompressive craniectomy and treatment-related complications were associated with poor outcome among patients with ISH, but not with ICH, which appeared per se as a more severe clinical condition. Conclusions: Our study confirm that age, Hunt-Hess and treatment-related complications influence the outcome of patients with ruptured MCA aneurysms. However, in the subgroup analysis of patients with SAH associated with ICH or ISH, only the Hunt-Hess at onset appeared as an independent predictor of outcome

Geometry and Symmetry of Willis' Circle and Middle Cerebral Artery Aneurysms Development

Background: A relationship between the geometry and symmetry of Willis' circle and intracranial aneurysms was reported for anterior communicating and posterior communicating (PCom) aneurysms. A similar association with the middle cerebral artery (MCA) aneurysms instead appeared weaker. Methods: We reviewed 432 patients from six Italian centers with unilateral MCA aneurysms, analyzing the relationship between the caliber and symmetry of Willis' circle and the presence of ruptured and unruptured presentation. CT-angiograms were evaluated to assess Willis' circle geometrical characteristics and the MCA aneurysm side, dimension and rupture status. Results: The hypoplasia of the first segment of the anterior cerebral artery (A1) was in approximately one-quarter of patients and PCom hypoplasia was in almost 40%. About 9% had a fetal PCom ipsilaterally to the aneurysm. By comparing the aneurysmal and healthy sides, only the PCom hypoplasia appeared significantly higher in the affected side. Finally, the caliber of the internal carotid artery (ICA) and the first segment of MCA (M1) caliber were significantly greater in patients with unruptured aneurysms, and PCom hypoplasia appeared related to the incidence of an ipsilateral MCA aneurysm and its risk of rupture. Conclusions: Although according to these findings asymmetries of Willis' circle are shown to be a risk factor for MCA aneurysm formation and rupture, the indifferent association with ipsilateral or contralateral hypoplasia remains a datum of difficult hemodynamic interpretation, thereby raising the concern that this association may be more casual than causal