Relevance of bleeding pattern on clinical appearance and outcome in patients with hemorrhagic brain arteriovenous malformations

Although several descriptions of the angioarchitectural features of brain arteriovenous malformations (AVMs) associated with higher hemorrhagic risk have been reported, the prognostic value of the different bleeding patterns still needs to be elucidated. This study evaluated the influence on clinical appearance and outcome of the parenchymal and non-parenchymal (subarachnoid hemorrhage - SAH - and intraventricular hemorrhage - IVH) bleedings associated with ruptured AVMs. Clinical records and neuroradiological examinations of 30 patients with hemorrhagic AVMs were reviewed in order to identify their angioarchitectural features and the associated bleeding pattern. These data along with demographic characteristics and treatment modality were dichotomized and their relationship with clinical status at admission and follow-up was tested. IVH as well as parenchymal hematomas larger than 20 cm³ appeared associated with a severe clinical status at admission, whereas SAH involving basal cisterns was significantly associated with unfavorable outcome. Age, sex and angioarchitectural features did not show significant association with the severity of the prognosis. However, none of these bleeding patterns appeared as an independent risk factor of poor outcome at multivariate analysis. In conclusion, our data emphasized the possibility that non-parenchymal bleeding may worsen the outcome of patients with hemorrhagic AVMs.