Chapter 33: Lower Extremity Peripheral Arterial Disease

INTRODUCTION

Lower extremity peripheral arterial disease (LEPAD) is a major cause of poor quality of life, disability, and significant morbidity and mortality in the United States.^{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17} In this chapter, LEPAD is used to refer to any arterial disease affecting the lower extremity, including occlusive, aneursymal, and vasculitic disease states. Even when asymptomatic, LEPAD has been shown to decrease mobility and bone mineral density^8,9,12,18; leads to foot ulcers and amputations^8,19; and be a strong predictor of subsequent cardiovascular (CV) disease, nonfatal CV events (e.g., myocardial infarction and stroke), and mortality.^6,10,20 Standard therapy for LEPAD should include antiplatelet therapy and be directed at control of risk factors including smoking cessation, lipid management, strict diabetic therapy, and control of blood pressure²¹ in attempts to stop progression of the systemic atherosclerotic process. Current therapy on symptomatic disease includes exercise therapy, antiplatelet medications, and a variety of percutaneous interventional and surgical procedures. Therefore, early diagnosis and appropriate therapy for LEPAD can significant improve quality of life and decrease significant morbidity and CV mortality.

This chapter will attempt to concisely

• review the epidemiology and determined risk factors of LEPAD,

• discuss the embryologic development and subsequent normal and variant anatomic features of LE vasculature,

• summarize the classification and grading schemata for LEPAD,

• discuss the pathophysiology underlying LEPAD and limb ischemia,

• review the common and uncommon etiologies of LEPAD,

• discuss the typical clinical presentation, physical examination findings, and natural history of LEPAD,

• summarize the various diagnostic modalities for LEPAD,

• review the medical and nonpharmacologic therapies for LEPAD,

• discuss the percutaneous and surgical revascularization procedures for LEPAD and outline the appropriate clinical indications for use of each therapy,

• discuss more specific therapy for critical limb ischemia (CLI), and

• summarize the current investigations and future directions in the treatment of LEPAD.

EPIDEMIOLOGY

Prevalence

It is without question that LEPAD is a common disease process affecting a significant portion of the adult population. There are a reported 413 000 discharges per year with chronic peripheral arterial disease (PAD), 88 000 inpatient lower extremity arteriographies, and nearly 30 000 discharges involving patients who had undergone embolectomy or thrombectomy of the lower limb arterial vasculature.²² Numerous epidemiologic studies have been performed in attempts to accurately quantify the prevalence of LEPAD in the adult population and although these studies have reported a variety of rates, most experts and consensus statements agree that up to 12 million individuals in the United States are affected by PAD. The variability found in these numerous studies evaluating LEPAD is widely attributable to the differing clinical presentations (namely asymptomatic individuals), ...