[Hemorrhage in arteriovenous malformations: clinical and anatomic data].

Background And Purpose: Potential severity of hemorrhage often leads to treat a cerebral arteriovenous malformation. Consequences can be very various and serious. Our first purpose is to define the different types of hemorrhage. Our second purpose is to appreciate more precisely individual hemorragic risk of a cerebral arteriovenous malformation with the study of his angioarchitecture. We performed a prospective study in order to validate a logistic model and a classification previously described.

Patients: and method. From the whole series of 705 patients, 57% (n=394) suffered a parenchymal, subarachnoid or ventricular hemorrhage. Logistic model and classification of the hemorrhagic risk were prospectively tested on a consecutive population of 78 patients. Comparisons of theorical (calculated hemorrhagic risk) and real (hemorrhage or not) were performed by non parametric tests.

Results: Characteristics and clinical consequences of the hemorrhage were analyzed. Results of the prospective study confirmed data of the classification and showed a hemorrhage risk increasing with the grade: grade Ia 0%, grade Ib 30%, grade II 44%, grade III 57%, grade IV 88%.

Conclusion: The study of the angioarchitecture of a cerebral arterio-venous malformation allowed to assess with accuracy his individual hemorrhagic risk. However, this precision may be improved by the study of other parameters of intracranial arteriovenous malformation.