We report a case of high-flow arteriovenous malformation with a giant feeder, which was treated by staged therapy without causing retrograde thrombosis. A 24-year-old woman was referred to our hospital with a giant arteriovenous malformation (AVM) in the right frontal lobe. She had experienced a dozen or more epileptic seizures since childhood. The main feeder of the AVM arose from one of the branches of the right middle cerebral artery (MCA). This feeder was thicker than the right internal cerebral artery and was 5 times thicker than the main trunks of the MCA. In addition, the AVM was supplied by the perforating arteries of the MCA and the anterior cerebral artery, and drained into deep veins with venous aneurysms. The main feeder was so thick that it was thought that sudden interruption could produce retrograde thrombosis, which could then cause occlusion of the main trunk of the MCA or total occlusion of the MCA. Therefore, we selected staged therapy.
In the first endovascular treatment session, we embolized one branch of the main feeder with coils and highly concentrated n-butylcyanoacrylate (NBCA), which slightly reduced the flow of the main feeder. The second endovascular treatment session was performed 1 month later via another branch of the main feeder. We inserted a microcatheter into the venous aneurysm through the shunt of the AVM and embolized part of the nidus that involved an aneurysm in the branch of the feeder using coils and a low concentration of NBCA. At that time, flow in the main feeder was reduced and flow in the normal branches of the MCA was moderately improved. One month after the second treatment, right carotid angiogram demonstrated further reduction of the main feeder and normalization of the MCA. Thereafter, we completely removed the AVM without any neurological deficit, and a postoperative angiogram demonstrated extirpation of the AVM without retrograde thrombosis.
There have been some reports of fatal artery occlusion due to retrograde thrombosis after sudden interruption of giant feeders of an AVM. In such cases, it is useful to perform staged therapy by a series of endovascular treatments followed by surgery.