The different clinical manifestations of PAD are a major cause of acute and chronic illness, leading to an impaired functional capacity and quality of life, as well as source of limb amputation or increased risk of death. Because atherosclerosis is a systemic process patients presenting with PAD frequently also present concomitant disease of the arteries to the heart and brain. This multi-level impairment of the arterial bed is the leading cause of morbidity and mortality in these patients, who frequently will experience several cardiovascular ischemic events, such as MI, or ischemic cerebral
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stroke. Since many years, PAD has become a major health problem in western countries with huge social and economic burden especially in the United States and Europe, and due to an upcoming increased prevalence of cardiovascular risk factors, mostly diabetes, also in Asia and other developing countries, PAD is increasingly recognized as a health burden worldwide.
TransAtlantic Inter-Society Consensus (TASC) Working Group
In 2000 the TASC working group published an international document dealing with the
“Management of Peripheral Arterial Disease” (1). This TASC document, which was update in 2007 (2), was aimed to create a consensus that provides an evidence-based, detailed review of the diagnosis and treatment of intermittent claudication (IC), critical limb ischemia (CLI) and acute limb ischemia (ALI).
The purposes of these guidelines were to (1) aid in the recognition, diagnosis, and treatment of PAD of the aorta and lower extremities; (2) aid in the recognition, diagnosis, and treatment of renal and visceral arterial diseases; and (3) improve the detection and treatment of abdominal and branch artery aneurysms. This document was addressed to all vascular and endovascular specialists, including angiologists, interventional radiologists, cardiologists and vascular surgeons who deal daily by treating PAD patients with these different types of atherosclerotic manifestations.
Patients with PAD often present with symptoms of leg ischemia. However, many patients are asymptomatic, particularly those first detected by ABI screening, and, among symptomatic patients, atypical symptoms are more common than classic claudication (15, 29). Accordingly, the TASC II and the 2005 ACC/AHA guidelines on PAD suggested the following distribution of clinical presentation of PAD in patients ≥50 years of age (2, 3):
Asymptomatic — 20 to 50%
Atypical leg pain — 40 to 50%
Classic claudication — 10 to 35%
Critical limb ischemia — 1 to 2%
1.5.3.1 Asymptomatic disease:
The majority of individuals with lower extremity PAD do not experience recognizable limb ischemic symptoms, and by this definition, they are “asymptomatic.”
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Many patients with PAD have unrecognized disease as illustrated by the following observations.
Detection of asymptomatic PAD has value because it identifies patients at increased risk of atherosclerosis at other sites. As an example: as many as 50 percent of patients with PAD have at least a 50 percent stenosis in one renal artery (58). Thus, patients with asymptomatic PAD, most often detected by ABI, should be aggressively treated with risk factor reduction (e.g. aspirin, lipid lowering, blood pressure control). In addition to protecting against coronary disease and stroke, lipid lowering may also slow progression of the PAD (59).
1.5.3.2 Symptomatic disease:
Intermittent claudication is the most common symptom in patients with lower extremity PAD.
Patient interviews, however, can be both an insensitive and poorly reproducible tool to define lower extremity PAD symptoms. In epidemiological surveys, population-based classification of lower
extremity PAD symptom status is performed by use of standardized questionnaires (60, 61). Data from such surveys in both the United States and Europe have demonstrated that asymptomatic lower extremity PAD is 2 to 5 times more prevalent than symptomatic lower extremity PAD.
By using the common ABI definition of lower extremity PAD (i.e. ABI<0.9), 11.7% of the
population may present large vessel lower extremity PAD on noninvasive testing, with a prevalence of intermittent claudication in this population of 2.2% in men and 1.7% in women (10).
Similarly, abnormal femoral or posterior tibial pulses were present in 20.3% of men and 22.1%
of women, suggesting that, the fraction of individuals with intermittent claudication dramatically underestimated the true prevalence of lower extremity PAD. Conversely, the presence of claudication symptoms was also an imperfect marker (i.e., had poor specificity) for lower extremity PAD, because an ABI<0.90 was found in only 69% of those with claudication symptoms. This suggests that the vast majority of lower extremity PAD patients have no classic claudication symptoms.
Among symptomatic patients, the perception of claudication can vary from severe, debilitating discomfort at rest to a bothersome pain of seemingly little consequence. The severity of symptoms of claudication depends upon the degree of stenosis, the collateral circulation, and the vigor of exercise.
Patients with claudication can present with buttock and hip, thigh, calf, or foot pain, either singly or in combination. The usual relationships between pain location and corresponding anatomic site of arterial occlusive disease can be summarized as follows:
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Buttock and hip = aortoiliac disease
Thigh = aortoiliac or common femoral artery
Upper two-thirds of the calf = superficial femoral artery
Lower one-third of the calf = popliteal artery
Foot claudication = tibial or peroneal artery
Physical examination in the patient with claudication can be normal, but commonly reveals diminished or absent pulses below the level of stenosis with occasional bruits over stenotic lesions and evidence of poor wound healing over the area of diminished perfusion (62). Other physical findings may include a unilaterally cool extremity, a prolonged venous filling time, shiny atrophied skin, and nail changes (63).
Buttock and hip claudication:
Patients with aortoiliac occlusive disease (Leriche's syndrome) may complain of buttock, hip, and, in some cases, thigh claudication. Bilateral aortoiliac disease that is severe enough to cause symptoms almost always causes erectile dysfunction in men; another diagnosis should therefore be entertained if impotence is absent. Conditions that resemble Leriche's syndrome are:
Osteoarthritis of the hip or knee joints,
Neurogenic claudication
Osteoarthritis can be distinguished clinically from aortoiliac disease because osteoarthritic pain may not disappear promptly after exercise, may be associated with weather changes, and may vary in intensity from day to day (usually worse in the morning or upon wakening).
Neurogenic claudication, also called pseudoclaudication, describes a pain syndrome due to lumbar neurospinal canal compression, which is usually due to osteophytic narrowing of the neurospinal canal. The clinical presentation often helps to distinguish vasculogenic (i.e. true) claudication from pseudoclaudication. Unlike true claudication, which occurs with walking and is relieved by stopping, pseudoclaudication causes pain with erect posture (lumbar lordosis) and is relieved by sitting or lying down. Patients with pseudoclaudication may also find symptomatic relief by leaning forward and straightening the spine.
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Thigh claudication:
Atherosclerotic occlusion of the common femoral artery may induce claudication in the thigh, calf, or both. Patients with occlusive disease of the superficial femoral or popliteal arteries have normal groin pulses but decreased pulses distally.
Calf claudication:
Calf claudication is the most common complaint. It is usually described as a cramping pain that is consistently reproduced with exercise and relieved with rest. Cramping in the upper two-thirds of the calf is usually due to superficial femoral artery stenosis, whereas cramping in the lower third of the calf is often due to popliteal disease. This type of cramping pain in the calf can be confused with two other conditions:
Nocturnal leg cramps — Nocturnal leg cramps occur among older and infirmed patients and are not associated with exercise. This complaint is thought to be neuromuscular rather than vascular in origin.
Calf pressure and tightness — This symptom is primarily seen in athletes, and is usually associated with chronic exercise. It is thought to be due to increased compartment pressure and may persist even after rest.
Foot claudication
Claudication of the foot is usually accompanied by occlusive disease of the tibial and peroneal vessels. Isolated foot claudication is rarely seen with atherosclerotic occlusive disease, but is commonly seen with thromboangiitis obliterans (Buerger's disease).
Ischemic rest pain
A severe decrease in limb perfusion can result in ischemic rest pain. Such discomfort typically occurs at night and involves the digits and forefoot. The pain may be more localized in patients who develop an ischemic ulcer or gangrenous toe. Affected patients frequently find that the pain is relieved by hanging their feet over the edge of the bed or, paradoxically, by walking around the room because of the gravitational effect of dependence on limb blood pressure. Chronic tissue ischemia may also result in ischemic neuropathic pain that is frequently described as throbbing or burning with a superimposed severe shooting pain up the limb.