Abstract
This chapter discusses the surgical management of unruptured arteriovenous malformations (AVMs). Cerebral arteriovenous malformations (AVMs) are clinically the most significant vascular malformations affecting the central nervous system. These complex lesions, generally thought to be of congenital origin, are characterized by aberrant connections between arteries and veins without an intervening capillary component. Surgical excision of arteriovenous malformations remains the definitive treatment. It remains the only treatment modality that provides the patient with the best chance of immediate and permanent cure. With the craniotomy and dural opening complete, the AVM is carefully inspected and study is made of its appearance in relation to the preoperative angiogram. One of the most feared complications following the removal of an AVM is delayed hemorrhage that commonly occurs within the first 12–24 hours following the operative procedure. The most common cause of delayed hemorrhage is bleeding from residual malformation. The risks of harboring an unruptured AVM have been shown not to differ from those of harboring an AVM that has bled in the past. The recommendation for treatment is a highly individual decision made only after consideration of many factors. The most important factors relate to the AVM itself which include size, location, configuration, blood supply, and venous drainage. It is suggested that the age, medical condition, and psychological implications must also be considered.