Angiographic findings and clinical significance of the anterior and posterior spinal arteries in therapeutic parent artery occlusion for vertebral artery aneurysms.

Three of 16 patients with vertebral artery (VA) aneurysms treated by parent artery occlusion suffered ischemic complications. The cause of the ischemic complications was brain stem or upper cervical spinal cord infarction due to occlusion of the anterior spinal artery (ASA), posterior spinal artery (PSA) and perforating arteries arising from the VA. Angiographic detection of ASA and PSA was studied in 71 consecutive patients (142 VAs) with various diseases who underwent digital subtraction angiography. The ASA and PSA originated from the bilateral VAs in 14% and 9%, unilateral VA in 73% and 35%, and were not detected in 13% and 56%, respectively. These results indicate that the rate of angiographic detection of the ASA originating from the bilateral VAs is considerably lower than that of previously reported anatomical studies. Special attention must be paid to the ASA, PSA and perforating arteries on preoperative vertebral angiography to prevent ischemic complications associated with therapeutic parent artery occlusion for VA aneurysms.