Subclavian Steal Syndrome: Balloon-Expandable Stent-Assisted Angioplasty of Near-Total Occlusion of the Subclavian Artery Using a Retrograde Transradial Approach with Immediate Complete Clinical Improvement

Abstract

Subclavian steal syndrome (SSS) is a fascinating vascular phenomenon in which a steno-occlusive lesion of the proximal subclavian artery (SA) causes retrograde flow in the ipsilateral vertebral artery (VA), away from the brain stem, leading to vertebrobasilar insufficiency. Because the vertebrobasilar circulation is a closed hydraulic system, this pressure difference creates retrograde flow, pulling blood from the contralateral vertebral artery to the basilar artery, and then down the ipsilateral VA, “stealing” from the cerebral circulation. For most patients, subclavian steal is well tolerated with medicinal therapy. In patients who have failed conservative treatment or have marked symptoms, endovascular intervention has become the primary treatment modality. Different endovascular antegrade or retrograde, catheter-based balloon- or stent-supported angioplasty approaches are used. Surgical options such as carotid-subclavian bypass are generally reserved for patients who have failed endovascular treatment.

This 51-year-old woman presented with a history of uncontrolled arterial hypertension, dyslipidemia, and heavy smoking. She had consulted a neurologist after suffering from orthostatic headaches, dizziness, and visual alterations for the last 18 months, and she had at least three syncopal episodes during that period. The patient had quit her job as a secretary and abandoned her tertiary studies because of her inability to concentrate due to persistent headaches and dizziness. Remarkably, she found that her symptoms were significantly alleviated when she was lying down. She also presented left arm dysesthesia and intermittent pain.

Blood tests showed hypertriglyceridemia and hypercholesterolemia, normal hemoglobin and C-reactive protein levels, and a normal erythrocyte sedimentation rate. Blood pressure measured on the right arm was 154/96 mmHg and on the left arm was 105/76 mmHg. On physical examination, her left arm was cool, and her left radial and ulnar pulses were nonpalpable. She had a mild left facial asymmetry and reported left perioral paresthesias and dizziness when standing up rapidly. Her neurologic exam was otherwise nonfocal.

Cardiological studies (echocardiogram and Holter) and cervical spine (MRI) evaluations were reported as unremarkable. First-ever neuroradiological studies included brain MRI, which was found unremarkable except for mild microvascular disease. MRA of the aortic arch and supra-aortic trunks revealed moderate stenosis of the origin of the left common carotid artery (CCC) and near occlusion of the proximal left SA. The right-hand VA was dominant, and the left VA was poorly seen. Diagnostic aortogram confirmed severe stenosis of the proximal left SA and selective angiogram of the right-hand VA confirmed retrograde flow in the left VA and left subclavian steal.

After extensive discussion with the patient and family regarding treatment options, including surgical bypass, the decision was taken to proceed with neuroendovascular intervention. Loading doses of 500 mg of aspirin and 50 mg of prasugrel were administered orally. Ninety minutes after prasugrel was administered, VerifyNow testing confirmed a platelet activity level of 48 platelet (P2Y12) reaction units (PRUs). Under local anesthesia, a 5F introducer sheath was placed at the right femoral artery, and a 6F introducer sheath was placed at the left radial artery. Through the femoral access, we navigated a pigtail catheter, which was used for control angiography and as a subclavian ostium marker/reference. Through the radial access, SA balloon angioplasty followed by stent-assisted angioplasty was performed. A final aortogram showed SA revascularization with normal antegrade flow through the SA and left VA. Examination of her left hand demonstrated significantly improved capillary refill, and the left arm blood pressure was considerably enhanced with near equalization compared to the right side. The patient had an uncomplicated subsequent hospital course with a remarkably rapid and complete reversal of her clinical symptoms.

This chapter describes this revascularization strategy, its rationale, and possible limitations.