What is arterial vascular disease?

Arterial Vascular Disease Overview

Arterial vascular disease encompasses a broad spectrum of non-coronary arterial syndromes caused by structural and functional alterations in arteries supplying the brain, visceral organs, and extremities, with atherosclerosis being the predominant pathologic process worldwide. 1, 2

Definition and Scope

• Arterial vascular disease includes all peripheral arterial territories: carotid, vertebral, upper extremity, mesenteric, renal, and lower extremity arteries 1
• The term "peripheral arterial disease" (PAD) specifically refers to atherosclerotic occlusion of lower extremity arteries resulting in reduced blood flow to the limbs 3
• PAD affects approximately 20% of adults older than 55 years and up to 50% of those 85 years and older 4, 5

Primary Pathophysiologic Mechanisms

Atherosclerotic Disease

• Atherosclerosis remains the most common pathologic process affecting the aorta and arterial branches globally, with risk factors including smoking, diabetes, hypertension, hyperlipidemia, family history, postmenopausal state, and hyperhomocysteinemia 1, 2
• Atherosclerotic stenosis causes progressive narrowing or complete occlusion of arterial lumens, typically in a multifocal distribution 6
• The disease process increases with age and relates directly to modifiable risk factors 6

Non-Atherosclerotic Arterial Diseases

• Connective tissue disorders: Marfan syndrome, Ehlers-Danlos syndrome, and Loeys-Dietz syndrome cause collagen abnormalities leading to loss of arterial wall structural integrity, aneurysm formation, and dissection 6, 2
• Fibromuscular dysplasia (FMD): The most common dysplastic disease, characteristically affecting the middle and distal two-thirds of renal arteries, as well as carotid and iliac arteries, with medial fibroplasia accounting for 80-85% of cases and producing a "string of beads" angiographic appearance 2
• Thromboangiitis obliterans (Buerger disease): A nonatherosclerotic inflammatory vasculitis affecting small- and medium-sized distal arteries of hands and feet, almost exclusively in heavy tobacco smokers aged 25-45 years, with an incidence of 12.6 per 100,000 in North America 6, 2
• Popliteal artery entrapment syndrome (PAES): The most common cause of surgically correctable lower-extremity vascular insufficiency in young adults, presenting with calf claudication, paresthesia, and swelling during exercise 6
• External iliac artery endofibrosis (EIAE): A rare cause of performance-limiting claudication occurring primarily in endurance athletes, particularly cyclists 6
• Cystic adventitial disease: An uncommon cause of arterial stenosis that may lead to thrombosis 6
• Segmental arterial mediolysis (SAM): A rare non-inflammatory arteriopathy 6

Vasculitic Disorders

• Giant cell arteritis (Takayasu disease): Affects large arteries, particularly the aortic arch and its branches 2
• Temporal arteritis: A form of giant cell arteritis affecting medium vessels 2
• Polyarteritis nodosa: Classically targets medium-sized vessels 2

Thrombotic and Embolic Disorders

• Primary prothrombotic states: Include protein C, protein S, or antithrombin III deficiencies; factor V Leiden; prothrombin mutations; lupus anticoagulant; anticardiolipin antibody; and malignancy-associated states 2
• Macroemboli: Originate from cardiac sources including left atrial appendage thrombus, atrial fibrillation, and ventricular thrombus 2
• Microemboli: Arise from cardiac valvular disease or arterial sources, particularly ruptured cholesterol plaques causing atheroembolization 2

Vasospastic Disorders

• Primary Raynaud phenomenon: Represents primary vasospasm without underlying disease 2
• Secondary Raynaud phenomenon: Occurs with scleroderma or systemic lupus erythematosus 2

Clinical Manifestations

Chronic Presentations

• Up to 50% of patients with PAD are asymptomatic 1
• Classic intermittent claudication: Reproducible pain in lower extremities consistently induced by exercise and relieved with rest, present in only 10-11% of PAD patients 7, 8
• Atypical leg pain: More common than classic claudication 1
• Ischemic rest pain: Indicates advanced disease 1
• Non-healing ulcers or wounds: Result from inadequate tissue perfusion 1, 7
• Gangrene: Represents tissue necrosis in severe cases 1

Physical Examination Findings

• Diminished or absent pulses 3
• Cool skin temperature 3
• Trophic changes (hair loss, skin atrophy, nail thickening) 3
• Pallor on elevation 3
• Absence of edema is characteristic of pure arterial disease; presence of edema suggests coexisting venous disease, heart failure, or other systemic conditions 3

Acute Limb Ischemia

• Represents a rapid or sudden decrease in limb perfusion threatening tissue viability 6
• The 5 "Ps" of acute limb ischemia: Pain, paralysis, paresthesias, pulselessness, and pallor (some add a sixth "P" for polar/cold extremity) 6
• May be the first manifestation of arterial disease in previously asymptomatic patients or occur as acute deterioration in patients with pre-existing PAD 6
• Embolic occlusion: Typically causes more severe ischemia when affecting vascular beds not previously conditioned by collaterals, often lodging at arterial branch points where lumen caliber diminishes 6
• Thrombotic occlusion: Usually occurs superimposed on stenotic atherosclerotic plaques, commonly in the superficial femoral artery 6

Common Pitfalls

• Underdiagnosis in primary care: Physician awareness of PAD diagnosis is relatively low (only 49% aware of prior PAD diagnoses), despite high prevalence 8
• Atypical presentations: The majority of PAD patients do not present with classic claudication symptoms, leading to missed diagnoses 7, 8
• Misattribution of edema: Peripheral edema in suspected PAD should trigger evaluation for alternative or coexisting conditions (venous disease, heart failure, renal disease), as pure arterial disease does not cause edema 3
• Inadequate risk factor management: Patients with PAD receive less intensive treatment for lipid disorders and hypertension and are prescribed antiplatelet therapy less frequently than patients with coronary or cerebrovascular disease, despite similar cardiovascular risk 8