gms | German Medical Science

Objective: Often patients with cerebral arterio-venous malformations (AVM) and high surgical risk due to their location in an eloquent area or large size were treated solely by radiosurgery and/or embolization. Some of these patients underwent neurosurgery because of recurrent hemorrhage or neurological deterioration. In a retrospective study we want to analyze the clinical features of those patients.

Methods: Over 10 years, 14 patients with cerebral AVMs who had previously undergone radiosurgery (stereotactic proton beam, gamma knife) and/or embolization in curative intention, underwent operative treatment in our department. The mean duration between initial therapy and final resection was 5 years.

Results: Preoperative angiography demonstrated a nidus size of 4-5 cm and newly developed 'en-passant' feeding vessels in all patients. Other new phenomena were venous stenosis and involvement of the external carotid circulation. The mean operation time during neurosurgery was 4 hrs. 30 min.. The clinical outcome of the patients was not favorable. Half of the patients suffered from persistent neurological deterioration. The Glasgow Outcome Scale was 5 in three, 3 in nine and 1 in two patients.

Conclusions: AVM's previously treated in curative intention by radiation and/or embolization should be assigned an additional Spetzler and Martin grade before resection. Angiographic studies revealed a 'wild-running' morphology. Neurosurgery was very challenging and led to unfavorable outcomes in many of the patients. Therefore, the radiosurgeon and/or neuroradiologist have to re-evaluate their 'curative' approach in treatment of AVMs with a nidus size over 3 cm.