Upper Extremities and Aortic Arch

Key Points

Arterial disease in one vascular bed is a harbinger of disease in other vascular beds.
The differential diagnosis of diseases involving the upper extremity (UE) and aortic arch branch vessels is vast and requires extensive knowledge and a thorough history and physical examination.
In patients with suspected arterial disease, blood pressure should be measured in both UEs, and if Takayasu arteritis is suspected, blood pressure should be measured in all four extremities.
Anatomic variation in the UE vessels and aortic arch occurs in 20% to 30% of the population, and the pathologic significance depends on the anomaly.
The physical examination of a patient with UE disease is incomplete in the absence of performing diagnostic maneuvers to evaluate for thoracic outlet syndrome (TOS).
Before performing percutaneous intervention for UE large vessel disease, the relationship of branch vessels to the lesion and ostial involvement of the lesion should be thoroughly evaluated.
Percutaneous intervention in the brachiocephalic artery is more complicated than revascularization of the subclavian artery due to the potential for embolization to the anterior cerebral circulation.
Percutaneous revascularization has become first-line therapy instead of surgery for treating atherosclerotic brachiocephalic or subclavian stenosis because of the high technical success rates, the low restenosis and high patency rates, and lower cost with quicker recovery times.
Management of UE arterial and aortic arch vascular disease requires discernment of when to refer patients to surgery and an understanding of the management of aneurysmal disease.

INTRODUCTION

From the inception of the subspecialty of interventional cardiology, to the Centers for Medicare and Medicaid Services (CMS) physician specialty designation for interventional cardiology, the scope of interventional cardiology has continued to expand. The discipline has grown beyond percutaneous management of coronary artery disease to include therapy for valvular and structural heart disease and endovascular treatment of aortic aneurysm, venous disease, and peripheral arterial disease (PAD), including management of vascular disease in the upper extremity (UE) and proximal arch vessels.

The continued evolution of cardiology in the field of vascular medicine has been a natural extension because atherosclerosis is a systemic process that is not isolated to the coronary vasculature, and a high degree of correlation exists between the extent of atherosclerosis in the coronary, carotid, and brachial arteries. Coronary disease is associated with an increased risk of PAD, and among those with PAD, the risk of coronary and cerebrovascular ischemic events with significant morbidity and mortality is extremely high. Most of the management concepts and techniques for coronary arterial disease are transferable to the treatment of PAD when a conservative medical strategy or percutaneous therapy is employed.

General and interventional cardiologists care for patients with coexistent coronary and peripheral vascular disease and those with significant risk factors for the development of arterial vascular disease. These clinicians must have a thorough understanding of PAD, including the application of screening tools and management strategies.

This chapter discusses the anatomy, epidemiology, risk factors, diagnosis, and treatment of PAD involving the UE (i.e., axillary and brachial arteries) and proximal arch vessel (i.e., subclavian artery). It excludes carotid arterial disease evaluation and management, which are discussed in Chapter 46 .

Epidemiology and Risk Factors for Peripheral Arterial Disease

Considering an age-adjusted prevalence of about 12%, PAD is estimated to affect at least 8 to 12 million individuals in the United States. Advancing age is strongly associated with the increased prevalence of PAD, and approximately 20% of U.S. adults older than 70 years have PAD.

PAD has been reported to affect males and females equally, but studies have demonstrated a greater predilection for PAD among blacks versus nonHispanic whites (38% vs. 25% of men), and the ethnic propensity is independent of traditional risk factors for cardiovascular disease such as hypertension, hyperlipidemia, diabetes, kidney disease, and tobacco use. An estimated 25% to 40% of patients seen in the general cardiology clinic have PAD, and up to 50% of patients with PAD may be asymptomatic, illustrating the need for careful evaluation of patients of advancing age and those with risk factors for cardiovascular and peripheral vascular disease.

Unlike PAD involving the lower extremities, atherosclerosis is estimated to account for only about 5% of cases of UE ischemia. Obstruction of the brachiocephalic (innominate) or subclavian (inflow) arteries accounts for most cases due to the propensity for atherosclerosis at those sites, with a fourfold higher occurrence on the left than the right. However, not all UE ischemia is related to inflow obstruction. Because of the relatively uncommon occurrence of atherosclerosis distal to the inflow arteries, numerous causes of UE arterial disease involving the large or medium-sized arteries (proximal to the wrist) or small arteries (distal to the wrist) must be considered. Conditions such as vasculopathies, aneurysm or entrapment syndromes, embolic phenomena, medications, and chemical exposures can complicate the diagnosis due to the similarity of symptoms. Additional testing beyond the comprehensive history and physical examination may be required to elucidate the cause. Table 40.1 provides the differential diseases, exposures, and other conditions that should be considered.

TABLE 40.1

Differential Diagnosis of Upper Extremity Vessel Obstructive Disease

Data from Rajagopalan S, Mukherjee D, Mohler E. Manual of Vascular Diseases . Philadelphia: Lippincott Williams & Wilkins; 2005:216; and Stone JH. Immune complex-mediated small vessel vasculitis. In: Firestein GS, Budd RC, Gabriel SE, et al, eds. Kelley’s Textbook of Rheumatology . 9th ed. Philadelphia: Saunders; 2012.

Vessel Size	Site, Disease State, and Substance	Symptoms and Physical Examination Findings	Symmetry and Acuity
M edium to Large
Atherosclerosis	Brachiocephalic artery Subclavian artery Axillary artery	Arm claudication Hand or finger pain Bruit, pulse deficit	Typically unilateral Chronic and progressive
Aneurysm	Thoracic outlet syndrome Trauma, crutch syndrome Vasculitis Fibromuscular dysplasia	Pulsatile mass in the supraclavicular fossa, hoarseness, dyspnea, transient ischemic attack (subclavian artery)	Unilateral Chronic and progressive
Thromboembolism	Heart Aortic arch Proximal great vessels	Varies (e.g., ischemia, pallor) according to cause Skin ulcers Osler nodes Janeway lesions	Unilateral, can be bilateral Typically acute
Entrapment	Trauma Thoracic outlet syndrome Neoplasm	Pain, especially with movement or certain positions	Unilateral Chronic and progressive unless it is an acute injury
Vasculitis or arteritis	Giant cell (temporal) arteritis Kawasaki disease Takayasu arteritis Radiation-induced arteritis	Constitutional symptoms (e.g., fever, weight loss, fatigue, arthralgias, myalgias), rash, bruit, pulse deficit	Unilateral or bilateral
Vasospasm	Nicotine Cocaine Methamphetamine	Digital pallor Cyanosis	Unilateral or bilateral Acute on chronic
S mall
Hematologic disorders	Cryoglobulinemia (types I, II, III) Myeloproliferative syndrome Multiple myeloma Leukemia Primary macroglobulinemia	Constitutional symptoms	Unilateral or bilateral, typically bilateral Progressively worsening
Hypercoagulable states	Antiphospholipid syndrome Antithrombin III, protein C, or protein S deficiency Heparin-induced thrombocytopenia	Variable, typically mimicking thromboembolic disease	Unilateral or bilateral, typically bilateral Progressively worsening
Rheumatologic disorders (vasculitis)	Rheumatoid arthritis Systemic lupus erythematosus Scleroderma, CREST syndrome, mixed connective tissue disease Henoch-Schönlein purpura	Constitutional symptoms, dysphagia, nail pitting, prominent nailbed capillary loops, skin lesions (e.g., erythema nodosum, petechial rash, pyoderma gangrenosum, palpable purpura), sclerodactyly, telangiectasias	Unilateral or bilateral, typically bilateral Progressively worsening
Infectious diseases	Hepatitis C Mycoplasma pneumonia	Variable, typically mimicking thromboembolic disease	Unilateral or bilateral, typically bilateral Progressively worsening
Embolic and thrombotic diseases	Buerger disease Atheromatous disease Aneurysms Atrial fibrillation Atrial myxomas Left ventricular thrombus ASD/PFO Endocarditis or valvular disease	Varies according to cause Skin ulcers Osler nodes Janeway lesions	Bilateral Acute
Vasospasm	Raynaud phenomenon Medications or illicit substances	Finger pain, fixed cyanosis, ulcers, gangrene	Typically bilateral Acute, chronic, or acute on chronic
Exposures	Vinyl chloride	Digital pallor Cyanosis	Unilateral or bilateral Chronic and progressive

ASD/PFO , Atrial septal defect or patent foramen ovale; CREST , calcinosis cutis, Raynaud phenomenon, esophageal dysfunction, sclerodactyly, telangiectasia.

Vascular Anatomy of the Upper Extremity and Aortic Arch

Normal Anatomy

The normal branching pattern of vessels coming off the aortic arch in approximately 70% of the population includes the initial branch, the right brachiocephalic artery, the left common carotid artery, and the left subclavian artery. Variations from the typical branching pattern are discussed in the next section.

The right brachiocephalic artery (innominate) divides into the right subclavian and the right common carotid artery behind the right sternoclavicular joint. The right subclavian artery then becomes the axillary artery at the lateral border of the first rib. The brachial artery, a continuation of the axillary artery, begins at the lateral border of the teres major muscle and terminates at the neck of the radius as it divides into the radial and ulnar arteries. The radial artery continues in the hand as the deep palmar arch, whereas the ulnar artery continues in the hand as the superficial palmar arch, which gives rises to the digital arteries. The left subclavian artery, the third branch off the aorta after the innominate and the left common carotid, has a branching pattern in the left UE that is analogous to the right. Fig. 40.1 demonstrates normal anatomy angiographically.

Smaller vessels provide extensive collateral circuits in the shoulder, elbow, and palm regions and are protective in allowing perfusion to the UE despite significant obstruction. UE large vessel disease is typically asymptomatic until the collateral support is insufficient or exhausted. Despite having protective collateral circuits, the UE remains vulnerable to ischemia if the obstruction occurs proximally because the UE is supplied by only one artery from the aorta.

Anatomic Variants

The anomalous circulation in the UE and aortic arch primarily results from alterations in embryologic development ( Fig. 40.2 ). Although an exhaustive review of embryologic development is beyond the scope of this chapter, the resultant aortic arch and proximal branching vessel variants are the consequence of aberrant formation, including persistence or abnormal regression, of the endocardial tube, the ventral and dorsal aortae, and the six paired branchial arch arteries or the intersegmental arteries.

Fig. 40.2, Embryologic transformation of the aorta to a normal adult pattern.

Table 40.2 lists some of the more commonly encountered variants, their frequencies in the population, associated pathologic significance, and diagnostic physical examination findings. The more common arterial variants in the forearm and collateral pathways that may form in the presence of main arterial obstruction are included. Figs. 40.3-40.5 show examples of variant anatomy.

TABLE 40.2

Arterial Variants and Collateral Pathways of the Upper Extremity and Aortic Arch

Data from Rajagopalan S, Mukerjee D, Mohler E. Manual of Vascular Diseases . Philadelphia: Lippincott Williams & Wilkins; 2005:39–43, 215; Kadir S. Atlas of Normal and Variant Angiographic Anatomy . Philadelphia: WB Saunders; 1991:xi, 529; Kaufman JA, Lee MJ. Vascular and Interventional Radiology : The Requisites . 2nd ed. Philadelphia: Elsevier; 2014 [chapter 6]; and Pellerito JS, Polak JF. Introduction to Vascular Ultrasonography . 6th ed. Philadelphia: Saunders; 2012 [chapter 13].

Anatomic Variants	Prevalence (%)	Pathologic Significance	Physical Examination Clues
Bovine arch: common origin of brachiocephalic and left common carotid arteries	22	None	No specific findings
Origin of left common carotid from the brachiocephalic (middle to upper)	8–10	None	No specific findings
Origin of left vertebral artery from the aorta	4–6	None	No specific findings
Origin of right subclavian from left aortic arch, distal to left subclavian (arteria lusoria)	2	Compression due to esophageal ring, prone to rupture and aneurysm (Kommerell diverticulum)	Dysphagia
Common origin of carotids	<1	None	No specific findings
Origin of radial artery from brachial or axillary artery	15–20	None	No specific findings
Origin of ulnar artery from brachial or axillary artery	2–3	None	No specific findings
Collateral Obstruction Site	Donor Artery	Pathologic Significance	Physical Examination Clues
Proximal subclavian or innominate obstruction	Vertebral, other neck, abdominal, or pelvic	Subclavian steal syndrome	Weak or absent pulse Decreased blood pressure Arm weakness or pain
Distal subclavian or axillary	Subscapular, intercostals, lateral thoracic	None, unless collateral supply insufficient, then ischemia	No specific findings
Brachial artery	Profunda brachialis, radial, ulnar	None, unless collateral supply insufficient, then ischemia	No specific findings