INTRODUCTION

Progressive atherosclerosis complicated by thromboembolic events is by far the most common cause of peripheral arterial disease (PAD). The atherosclerotic process is a generalized disorder that almost invariably affects many vascular beds; therefore, any patient who presents with symptoms or signs suggestive of atherosclerotic disease in one vascular bed is likely to have other territories involved as well (Fig. 25.1). The common risk factors for atherosclerosis also apply to PAD, but the order of importance varies: smoking and diabetes correlate most strongly with disease of the leg arteries and predict its progression. The disease in the leg arteries remains clinically silent as long as no hemodynamically significant obstructive lesions develop. With the aid of simple noninvasive tests in middle-aged adults, subclinical disease is detected three to four times more often than is symptomatic disease (Fig. 25.2). Intermittent claudication, or leg pain on exercise that is relieved by rest, develops when the distal perfusion pressure decreases secondary to the high resistance in the proximal diseased arteries and the collateral vessels. Progression of the disease, to the extent that the blood flow is unable to meet the metabolic and nutritional demands of resting tissues, is clinically manifested by rest pain and skin lesions on the feet.