Refractory Spontaneous Chronic Subdural Hematoma: A Rare Presentation of an Intracranial Arteriovenous Fistula.

The author has encountered a 67-year-old man with dural arteriovenous fistula (AVF) presenting as a non-traumatic chronic subdural hematoma (CSDH). This previously healthy patient was hospitalized due to progressive headache with subacute onset. He underwent burr-hole surgery twice for evacuating the left CSDH that was thickest at the posterior temporal area. The operative procedure and finding was not extraordinary, but subdural hematoma slowly progressed for days following the revision surgery. After investigation by super-selective external carotid angiography, a dural AVF found near the transverse-sigmoid sinus was diagnosed. Dural AVF was completely occluded with trans-arterial injecting polyvinyl alchol particles into the petrosquamosal branch of the middle meningeal artery. The patient showed a good neurological outcome with no additional intervention. Brain surgeons have to consider the possibility of dural AVF and perform cerebral angiogram if necessary when they manage the cases that have a spontaneously occurred and repeatedly recurring CSDH.