Peripheral Vascular Disease and its Symptoms
Obstructive vascular disease of the lower extremities is a widely recognized peripheral vascular disease (PVD) in adults. In 90% of cases, atherosclerotic plaques cause the obstruction (27). PVD increases with age, with an estimated prevalence of 12% to 17% among those over age 50 (28).
PVD may be present for many years before symptoms and signs of obstruction develop. Approximately 7% to 9% of persons with PVD develop intermittent claudication, (IC) the primary symptom of obstructive vascular disease of the lo wer extremity. With severe arterial insufficiency, necrosis, neuropathy and atrophy may occur (29,30,31). The occurrence of pain at rest marks the onset of a critical degree of ischemia.
Diagnosis
At times, the clinical history of IC may be confused with other medical conditions, including venous claudication, chronic compartment syndromes, peripheral nerve pain from a herniated disc, spinal cord compression, and osteoarthritis of the hip. However, each of these other disease entities has specific symptoms and findings that aid in making the diagnosis.
The diagnosis of IC may be suspected from the characteristic history of slowly developing aching leg pain on exercise that is relieved by rest. Absence of a femoral artery, posterior tibial or dorsalis pedis pulse on physical examination may indicate PVD, although approximately 10% of normal adults lack at least one of these three pulses. In addition to palpation, auscultation over the arteries may detect a bruit, indicative of partial obstruction with resulting turbulence of the blood flow.
The skin of the legs may have changes in color and temperature. The skin may also reveal changes associated with chronic ischemia, including thin, dry skin, loss of hair, loss of subcutaneous fat, and thickened nails.
The level and the extent of the blockage determine the location of the pain and the amount of exercise required to cause the pain. Among those under 40, aortoiliac disease is more common, while femoral-popliteal disease causes two-thirds of the cases of claudication in people over age 40. Superficial femoral obstructive disease generally causes pain in the calf; aortoiliac or internal iliac disease usually causes aching pain in the thigh, hip or buttocks (31,32,33).
142 Associated Cardiovascular Disease
Muluk et al. reported that the yearly mortality rate was 12% among those with IC, much more than the age-adjusted mortality in the United States population (34). The
atherosclerotic changes found in the peripheral arteries are often present in other vessels in the body (29). Among those with symptomatic PVD, the 10- year mortality rate from CVD is 10 to 15 fold greater compared to those without symptoms. A significant majority of patients with PVD die from cardiovascular diseases, with the majority of deaths from coronary heart disease (29,35,36,37).
Clinical Course
PVD is usually a slowly progressive disease with a benign course and essentially no risk for sudden incapacitation. Approximately 25% of those with claudication develop
worsening symptoms, usually in the first year (30,31,38). Systolic hypertension, cigarette use, diabetes and hyperlipidemia can each increase the likelihood of developing
increasingly severe PVD (33,39,40). In more advanced cases, ulceration and/or gangrene may be present.
For the commercial vehicle driver, rest pain represents a critical degree of ischemia and is disqualifying because of the likelihood of reduced dexterity of the affected limb. The reported rates for surgical revascularization, angioplasty or amputation have ranged from 3% to 22%. The amputation rate is less than 10% at 10 years (29,31,34).
Treatment
Risk factor modification, especially stopping smoking, is the cornerstone of treatment. Staying active carries little risk for the person with IC; an exercise program designed to increase the activity of a person with IC has been effective (38).
Although more promising pharmacotherapy is being researched, there is currently limited pharmacological treatment for IC. Anti-platelet agents are used to treat a variety of atherosclerotic conditions. The effectiveness of oral anticoagulants is more uncertain. Tangelder reported that use of an oral anticoagulant at a dose to maintain the INR
between 3.0 and 4.0 is optimal therapy to prevent infrainguinal bypass occlusion. In this study, there were 0.9 ischemic and 2.9 hemorrhagic events per 100 patient years (41). The use of oral anticoagulant is not disqualifying, but does require more intensive monitoring, with at least monthly INR measurements to help assure appropriate
anticoagulation. The role of aspirin after lower extremity grafting has been difficult to define. Current drug treatments do not appear to prevent the commercial vehicle driver from working (42,43).
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Surgery and angioplasty are successful in treating persons with severe leg ischemia when other non- invasive treatments, including risk factor modification, have failed.
Angioplasty is more effective in the treatment of common iliac disease and for short segment disease. Below the inguinal ligament, however, the patency rate is decreased (44). Chetter reported a cumulative patency rate with angioplasty of 75% at six months, at the same time noting that patency rates from 50% to 90% had been reported for iliac lesions and 43% to 75% for femoral-popliteal lesions (45). Lower extremity bypass graft patency rates of 70% at five years, with a limb salvage rate of 91% at five years reported (46).
The commercial driver who has had a vascular procedure needs time to recover from the surgery, to be regulated on medication(s), and observed for early graft failure. The majority who return to commercial driving after surgery have done so by six months.
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