Background: Spinal artery aneurysms are rare, and are usually found in association with arteriovenous malformations or coarctation of the aorta.
Case report: A 42-year-old man with a ruptured anterior spinal artery aneurysm is presented here. He experienced subarachnoid hemorrhage, which was confirmed by computed tomography. Magnetic resonance imaging revealed an aneurysm in front of the upper part of the medulla. Angiography demonstrated bilateral vertebral artery occlusion. Distal vertebral arteries and the basilar artery were perfused via the dilated anterior spinal artery, which originates in the right subclavian artery. The aneurysm was located at the distal part of the anterior spinal artery, and was successfully clipped through a lateral suboccipital craniotomy 2 months after bleeding from the aneurysm. After rehabilitation, the patient was able to walk with no apparent neurologic deficit.
Conclusions: This case suggests that the anterior spinal artery as a collateral route after bilateral vertebral artery occlusion is under hemodynamic stress, resulting in aneurysm formation and rupture.