11: INNOMINATE AND SUBCLAVIAN ARTERY PERIPHERAL ARTERIAL DISEASE

PATIENT STORY

A 62-year-old woman presented to the emergency department (ED) with worsening digital ecchymosis of her second through fifth fingers of the left hand with progressive pain over the preceding 3 weeks. She denied any history of dizziness, syncope, or symptoms of a stroke in the past. She also denied symptoms of upper extremity claudication. She was examined and found to have weak pulses in the brachial, radial, and ulnar arteries on the left side. The hand did not appear to be acutely threatened.

The patient underwent a computed tomographic angiogram (CTA) with findings of a significant proximal left subclavian artery stenosis (Figure 11-1). She subsequently underwent an angiogram with left subclavian artery stent placement (Figure 11-2). She was maintained on clopidogrel and recovered uneventfully.

EPIDEMIOLOGY

Peripheral Arterial Disease

• Progressive narrowing of the arteries due to atherosclerosis.¹

• Mostly silent in early stages until luminal narrowing exceeds 50% of the vessel diameter.²

• Prevalence of peripheral arterial disease (PAD) in adults over 40 years in the United States is approximately 4%.²

• Prevalence of PAD in adults over 70 years in the United States is approximately 15%.²

• 20% to 25% of patients will require revascularization.²

• Approximately 5% of patients will progress to critical limb ischemia.²

• Patients with limb loss have 30% to 40% mortality in the first 24 months.²

ETIOLOGY AND PATHOPHYSIOLOGY

Peripheral Arterial Disease

• Global arterial tree inflammation accounts for atherogenesis and participates in local, myocardial, and systemic complications of atherosclero-sis.³

• Vascular risk factors including diabetes, hypertension, hyperlipidemia, and tobacco abuse augment cell adhesion molecules, which promote leukocyte binding to the arterial cell wall. This process perpetuates, causing remodeling of the arterial wall and lipid deposition within the tunica me-dia. This process continues and begins to narrow the vessel lumen, and eventually causes calcification of the arterial wall.³

• Disease of the brachiocephalic arteries can manifest in several ways including stroke or transient ischemic attack (TIA), upper extremity ischemia or claudication, and vertebrobasilar insufficiency related to subclavian steal syndrome.⁴

• The brachiocephalic arteries including the innominate and subclavian can be affected by vasculitides like Takayasu arteritis and giant cell ...