A Case Report on Acquired Pial Arteriovenous Fistula Supplied by Both Internal and External Carotid Arteries

Abstract

Here, we report a case of acquired pial arteriovenous fistula (AVF) supplied by both internal and external carotid arteries. The patient was a 69-year-old man who had subarachnoid hemorrhage due to a ruptured left middle cerebral artery aneurysm and underwent neck clipping in 2009. Magnetic resonance imaging revealed infarction in a portion of the left temporal lobe. Digital subtraction angiography demonstrated obstruction of the inferior trunk of the left middle cerebral artery and blood flow to the left temporal lobe through a leptomeningeal anastomosis from the left posterior cerebral artery. Follow-up digital subtraction angiography 9 years after the operation showed an AVF supplied by the middle meningeal artery, middle deep temporal artery, and artery of the foramen rotundum from the external carotid artery and by some branches of the middle cerebral artery from the internal carotid artery. The drainage route was the superficial Sylvian vein with retrograde cortical venous drainage. Endovascular embolization was performed using fiber coils, followed by surgical ligation of the AVF. The obvious fistulous point that connected the dura and the superficial Sylvian veins was not identified, but the AVF located on the brain surface was mainly supplied by the cortical middle cerebral arteries and drained into the Sylvian vein via a venous pouch. Therefore, we diagnosed a pial AVF. The fistulous point was removed after coagulation, and some arteries were cut and connected to the venous pouch. This case demonstrated the possibility of pial AVF supplied by both internal and external carotid arteries after cerebral infarction and craniotomy.