Acute management of brain arteriovenous malformations.

OPINION STATEMENT: Major reasons to treat brain arteriovenous malformations (AVMs) are to reduce the risk of brain hemorrhage, control intractable seizure, and in some cases alleviate neurologic deficits. Once an AVM has hemorrhaged, the risk of further hemorrhage is increased and it should be treated. The treatment plan ideally is based on interdisciplinary discussion between neurosurgery, endovascular neuroradiology, and radiotherapy, moderated by neurology in an experienced center. Complete removal or obliteration of the malformation should be the goal, as partial treatment only exposes the patient to treatment risks with a residual hemorrhage risk. If an AVM is surgically accessible with acceptable treatment risk, neurosurgical removal leads to the fastest and most complete reduction of hemorrhage risk. Radiotherapy is best used in small AVMs with contraindications to surgery. Endovascular embolization can be used as an adjunct for both to facilitate removal or obliteration or to reduce risks from associated aneurysms or high-flow fistulae, and may in some cases lead to complete occlusion. Unbled AVMs require a thorough assessment of projected hemorrhage risk versus treatment risks, as the natural course is influenced by clinical and morphological factors. Given recent scientific evidence, those with low projected hemorrhage risks should be managed conservatively, receiving the best medical treatment of accompanying symptoms, and careful clinical and follow-up imaging monitoring. Thorough and objective counselling of the patients about pros and contras of therapy, detailed explanation of recommendations, and possible reevaluation of treatment decisions at later timepoints are recommended.