Thalamic and basal ganglia arteriovenous malformations: redefining "inoperable".

Deep arteriovenous malformations of the basal ganglia and thalamus have an aggressive natural history and present a therapeutic challenge. More often than not, these lesions are deemed "inoperable" and are treated expectantly or with stereotactic radiosurgery. In some cases, clinical details combined with an opportune route of access dictate surgical resection. History of hemorrhage, small lesion size, and deep venous drainage each add to the aggressive natural history of these malformations. Interestingly, these same factors can point toward surgery. We present a discussion of the microsurgical techniques involved in managing these lesions, with an emphasis on situations that allow these lesions to be approached surgically.