[Cerebral arteriovenous malformations: evaluation of the hemorrhagic risk and its morbidity].

Evaluation of the hemorrhagic risk associated with intracranial arteriovenous malformation is a keypoint question for physicians involved in the management of these patients. Indeed, this hemorrhagic risk including its morbid-mortality consequences has to be balanced with the therapeutic risk. All the published studies have estimated the annual bleeding risk between 2 to 4%; a first hemorrhagic event is associated with an increased risk of a new bleeding. Mortality associated with AVM bleeding is estimated between 10 to 15%, with a 50% risk of morbidity. Factors associated with an increased risk of bleeding include existence of aneurysms (intranidal or flow related pedicular, proximal or distal) and some venous drainage patterns such as deep venous drainage or venous stenosis.