Solitary spinal artery aneurysms as a rare source of spinal subarachnoid hemorrhage: potential etiology and treatment strategy

Abstract

Solitary aneurysms of spinal arteries lacking associated vascular malformations are rare. We report three patients with spinal subarachnoid hemorrhage (SAH) due to rupture of such aneurysms, which regressed spontaneously, as confirmed on conventional angiography. One patient had spinal SAH with presumed spontaneous dissection of a segmental artery. In the other two, SAH resulted from ruptured fusiform aneurysms of the artery of Adamkiewicz immediately proximal to the anterior spinal artery. Solitary aneurysms of the spinal arteries appear to be etiopathologic entities completely different from intracranial aneurysms. Spontaneous occlusion seems to be common, justifying a wait-and-see strategy rather than urgent treatment.

Fig 1.

Case 1. Sagittal T1- (left) and T2-weighted (right) MR images show SAH extending from T2 to T6.

Fig 2.

Case 1. Left, Posteroanterior angiogram shows a small fusiform aneurysm of the radiculopial artery at the level of T5 collateralized by segment artery T6. Image does not show the segment of the artery at T5. Right, Posteroanterior control angiogram does not show the aneurysm but does depict the opacified segment of the arteries at T5 and T6.

Fig 3.

Case 2. Thoracolumbal MR images and contrast-enhanced MR angiogram (CE-MRA) shows a severe SAH and aneurysm at the level of T12 (arrow).

Fig 4.

Case 2. Posteroanterior angiograms show a partially thrombosed fusiform aneurysm of the radiculomedullary branch of the artery of Adamkiewicz originating from the left side of L1. The aneurysm occurs immediately before the radiculomedullary artery reaches the longitudinal anterior axis supplying the anterior spinal artery. This aneurysm, with spatial extension of about 5 × 7 mm, was nearly identically depicted on MR angiography (Fig 3).

Fig 5.

Case 2. Control MR images obtained 6 months after initial episodes of transient paraplegia show posthemorrhagic adhesions and a central spinal cord infarct at level T12 but not the patient’s aneurysm.

Fig 6.

Case 2. Control angiograms of the segment artery at left L1. Images show complete occlusion of the aneurysm, as well as the artery of Adamkiewicz and the anterior spinal artery.

Fig 7.

Case 3. Posteroanterior angiogram (left and middle) and 3-month control angiogram (right) in a patient with a fusiform aneurysm in the artery of Adamkiewicz originating from the left side of L1. Like case 2, the aneurysm occurs immediately before the radiculomedullary artery reaches the longitudinal anterior axis supplying the anterior spinal artery. Control image shows spontaneous aneurysm occlusion without therapy.