Efficacy analysis of Onyx embolization in combination with gamma knife surgery for the treatment of intracranial arteriovenous malformation

Objective To investigate the effectiveness and safety of Onyx embolization in combination with gamma knife surgery for the treatment of intracranial arteriovenous malformations (AVMs). Methods A total of 86 patients with AVM admitted to the Neurological intervention Center, Beijing Neurosurgery Institute, Capital Medical University and treated with Onyx embolization in combination with gamma knife surgery from April 2004 to September 2011 were analyzed retrospectively. The related complications and clinical prognosis of embolization were counted and analyzed. During the embolization of AVMs, the combined high risk of bleeding (intracranial aneurysms, hemodynamic aneurysms, and AVM-related arteriovenous fistula) were assessed and embolized. According to the risk factors and embolization or not, the intracranial AVMs with high risk factors were divided into either a targeted embolization group or a non-targeted embolization group. The effect of targeted embolization on hemorrhage risk was assessed. Results The overall annual hemorrhage rate in patients with AVM was 1.66%, and the ruptured AVM was 2.26%, the unruptured AVM was 1.08%, and the annual mortality rate was 0.74%. One of 16 patients with embolization related complications had permanent neurological dysfunction. Twenty-four of 29 patients complicated with intranidal aneurysm underwent targeted embolization; 4 of 5 patients with hemodynamic aneurysm underwent targeted embolization; and 8 of 9 patients with arteriovenous fistula underwent targeted embolization. Chi square test showed that the hemorrhage complications of the targeted embolization group was significantly lower than that of the non-targeted embolization group (P<0.01). Conclusion The targeted embolization in combination with gamma knife surgery may decrease the risk of intracranial AVM hemorrhage, improve clinical prognosis and occur less permanent complications. This method is suitable for the treatment of intracranial AVMs of larger volume and those can not be cured with a single program. Key words: Intracranial arteriovenous malformations; Cerebral angiography; Radiotherapy; Hemorrhage; Postoperative complication