A. Arteriovenous Malformations AVMs are approximately one seventh to one tenth as common as cerebral aneurysms with between 2,500 to 3,000 new cases presenting each year. An estimated 280,000 patients are afflicted with AVMs in the United States. The natural history of AVMs is incompletely understood. There is an increased risk of rupture with smaller malformations, AVMs with associated aneurysms, a single draining vein, deep venous drainage or venous stenosis. AVMs most frequently present as a consequence of hemorrhage in patients in their third and fourth decades.
Cerebral angiography remains the gold standard for diagnostic evaluation of putative AVMs.
Endovascular therapy, applying catheter administered materials for embolization, is a useful adjunct to microsurgery and stereotactic radiosurgery to diminish the degree of arterial shunt. Embolization is rarely curative alone, however. In younger patients possessing superficial lesion in noneloquent areas, microsurgery is clearly the treatment of choice. Microsurgery is also more effective than radiosurgery in ameliorating symptoms of patients with intractable epilepsy and headaches. Stereotactic radiosurgery invokes vascular injury and produces delayed thrombosis after months to years.