LOS ANGELES — Claudication in peripheral arterial disease can present in many different ways, a fact that isn't always appreciated by physicians, Allan V. Abbott, M.D., said at the annual meeting of the California Academy of Family Physicians.
About 33% of patients with peripheral arterial disease (PAD) present with classic claudication, “which means that pain comes on during exercise but goes away within 10 minutes of rest,” said Dr. Abbott, professor of family medicine at the University of Southern California, Los Angeles.
Another one-third will have atypical exertional leg pain symptoms, “which means that they have similar pain but it doesn't cause them to stop walking,” or they have similar pain that that does not involve the calves or does not resolve within 10 minutes of rest.
As for the remaining patients, he said, “some of them will have pain both at rest and on exertion, a few of them will have no exertional leg pain and be physically active, and some won't have any exertional leg pain because they aren't active.”
In the general population, claudication affects 10% of people over age 70 years compared with just 1%–2% of those aged 37–69 years.
In your differential diagnosis, nonvascular causes of claudication include arthritis of the hips, restless leg syndrome, peripheral neuropathies, spinal stenosis, and a prolapsed intervertebral disk. Vascular causes include thromboangiitis obliterans (Buerger's disease), and deep venous thrombosis.
Most of the lesions in PAD occur in the middle part of the leg around the knee. The most common kind of claudication occurs in the calf. “It's most commonly in the upper part of the calf,” said Dr. Abbott, who is also associate dean for curriculum and continuing medical education at the Keck School of Medicine in Los Angeles. “That's usually due to superficial femoral artery stenosis.”
Claudication that occurs in the lower third of the calf is usually due to popliteal disease. Thigh claudication can happen occasionally, usually due to femoral artery stenosis, while foot claudication “is really rare,” he said.
Buttock and hip claudication can occur from aortoiliac disease. “After you've ruled out arthritis, patients with aortoiliac disease will generally be impotent,” Dr. Abbott said. “If they are not impotent, chances are they don't have serious vascular disease at all.”
If you suspect PAD, the ankle-brachial index (ABI) is an effective noninvasive test for diagnosis. “Examination of pulses alone is not a reliable way to diagnose PAD,” he said.
In patients with PAD, the resting systolic pressure in the ankle should equal or exceed that of the arm. Any time the ABI ratio is below 0.9, “it's abnormal, it's PAD,” he said. “If it's between 0.5 and 0.9 it's mild to moderate. If it's less than 0.5 it's severe.”
When ABI indicates PAD, the level and extent of disease are determined by segmental limb pressure testing. “This can be done in your office but it's more commonly done in the vascular lab,” he said.
Other noninvasive tests for PAD include exercise treadmill tests, segmental volume plethysmography, ultrasonography, MRI, and magnetic resonance angiography.
Chronic Arterial Insufficiency Signs
Limb exam (and comparison with the opposite limb) includes:
▸ Hair loss.
▸ Poor nail growth (brittle nails).
▸ Dry, scaly, atrophic skin.
▸ Dependent rubor (redness).
▸ Pallor with leg elevation after 1 minute at 60 degrees. Normal color should return in 10–15 seconds. If it takes longer than 40 seconds, this indicates severe ischemia.
▸ Ischemic tissue ulceration (punched-out, painful, with little bleeding), gangrene.
▸ Absent or diminished femoral or pedal pulses, especially after exercising the limb.
▸ Arterial bruits.
Source: Dr. Abbott