Arteriovenous malformations of the basal ganglia region: Rationale for surgical management

Surgical indications for arteriovenous malformations (AVMs) arising at the region of the basal ganglia are questionable and the majority of cases are considered inoperable. Albeit not free from risks of morbidity and mortality, the treatment of choice is usually radiosurgery for small lesions, and embolization plus radiosurgery for larger lesions. Nevertheless, some lesions may be amenable for surgical resection due to their favorable location. Eighteen cases of such AVMs were selected for a direct approach in our series. Seventeen cases were classified as Spetzler and Martin [22] grade III, and one case was a grade V. Ten patients were males and eight females. The mean age was 28.3 years (ranged from 2 to 43 years). Sixteen patients had had previous hemorrhagic events prior to hospital admission. Eleven patients had pre-operative well stablished neurological deficits, and seven patients although symptomatic had a normal neurological exam at admission. Fifteen patients had their AVMs completely resected. Among the eleven patients with previous neurological deficts nine had no change in their pre-operative condition and two experienced postoperative neurological worsening. In the long-term follow-up six patients had a complete recovery and five recovered only partially. Among the seven patients whose neurological examination was normal pre-operatively five remained unchanged, one had a transient motor deficit, and one died due to a thalamic venous infarction and massive bleeding into the thalamus. The anatomical knowledge and the precise localization of the arteriovenous malformation through the aid of neuroimage studies has provided the means to classify these AVMs and plan operative strategies for some small selected cases with relatively low morbidity.