Complete resolution of vertebrobasilar dissection and aneurysm following treatment of subclavian steal physiology

Abstract

Subclavian steal syndrome results from subclavian artery stenosis that results in retrograde blood flow through the ipsilateral vertebral artery. Rarely, this retrograde flow can affect the vertebrobasilar junction and cause vertebrobasilar insufficiency, ischemia, and even aneurysm formation. We describe a unique presentation of a vertebrobasilar aneurysm presenting with subarachnoid hemorrhage in the setting of subclavian steal syndrome. The subclavian stenosis was endovascularly managed, with complete resolution of both retrograde flow and the dissection itself. Reestablishment of native flow mechanics in the subclavian artery may treat aneurysms at the vertebrobasilar junction, potentially eliminating the need for further interventions.

Keywords: Endovascular stenting; Subclavian steal; Subclavian stenosis; Vertebrobasilar aneurysms.

Fig 1

(A) Initial diagnostic cerebral angiogram demonstrating saccular aneurysm (yellow arrow) and small dissection flap (red arrow) of the distal left vertebral artery, just proximal to the VBJ. This angiogram also demonstrated retrograde flow in the left vertebral artery. (B) Three-dimensional rotational angiography demonstrating the aneurysm. (C) Preoperative computed tomography angiogram demonstrating left subclavian stenosis. Three-dimensional rotational angiography demonstrating the aneurysm.

Fig 2

(A) Completion angiogram after stent deployment in the proximal left subclavian artery, demonstrating restoration of antegrade flow mechanics. The origin of the left vertebral artery may appear stenotic in this projection, but it is just a result of the angulation and tortuosity of the origin. (B) Near complete resolution of saccular and fusiform aneurysm of the distal left vertebral artery approximately 3 months after intervention. (C) Computed tomography angiogram at the 2-year follow-up demonstrating patent subclavian stent.