Surgery after embolization of cerebral arterio-venous malformation: experience of 123 cases

A group of 123 patients with large or critically located arterio-venous malformations (AVMs), operated on between 1990 and 2011 and who underwent preoperative embolization, was assessed in order to clarify the risks of this combined treatment. AVM location, volume, and Spetzler's grade were assessed in each case; AVM volume was over 20 cm(3) in 49 % of the cases; Spetzler's grade was 3 or above in 76 % of the cases (with 34 cases in grades 4-5). A mean of 2.3 embolization procedures per patient were carried out, using bucrylate and, more recently, Onyx and/or Glubran; a 4.5 % procedure-related complication rate was observed. Complications occurring after surgery were classified as hemorrhagic (16 cases, 8 requiring surgical evacuation) or ischemic (4 cases); hemorrhagic complications were more common for AVMs with volumes >20 cm(3) and/or deep feeders. Surgery-related unfavorable results (modified Rankin Score > 2) were observed in 6 % of patients in Spetzler's grade 3, and in 20-25 % of patients in grades 4-5. More recently, a triple treatment (radiosurgery + embolization + surgery) allowed for obtaining favorable results (mRS 0-2) in all patients. It has been concluded that a combined treatment with embolization and surgery constitutes a reasonable choice for complex cerebral AVMs; the association of radiosurgery may improve the patients outcome.