Gamma knife surgery for the treatment of spontaneous dural carotid-cavernous fistulas.

Endovascular treatment for a spontaneous dural carotid-cavernous fistula (CCF) is an established treatment, but stereotactic radiosurgery might provide a less-invasive alternative in selected cases. Four women aged 67 to 79 years (mean 72.0 years) with spontaneous dural CCFs presented with chemosis or bruit. Angiography revealed arteriovenous fistulas in the cavernous portion. Three cases were Barrow type D and one was type B converted from type D. Stereotactic gamma knife surgery was performed with a marginal dose of 13-15 Gy and a maximum dose of 26-30 Gy with a volume from 824 to 1755 mm3. The target point of radiosurgery for type D CCFs was the compartment of the cavernous sinus supplied by multiple feeders from the external carotid artery. All patients responded favorably to the treatment, with improvement of symptoms beginning after 1 to 3 months. Angiography confirmed the complete disappearance of the CCFs in all patients. There were no recurrences, and the follow-up period was 14 to 32 months (mean 24 months). No significant side effects were observed. Stereotactic radiosurgery is a useful method to treat CCFs and is indicated for elderly patients, low-flow CCFs, and cases in which endovascular treatment has failed.