LECTURE 4: PERIPHERAL ARTERIAL DISEASE OF THE LOWER EXTREMITIES
PAD of the lower extremities affects the aortoiliac, femoral, popliteal, tibial, or peroneal
The classic symptom of PAD of the lower extremities is intermittent claudication,
which is defined as ischemic muscle ache or pain that is precipitated by a consistent level
of exercise, resolves within 10 minutes or less with rest, and is reproducible.
Paresthesia, manifested as numbness or tingling in the toes or feet, may result from nerve
tissue ischemia. Gradually diminishing perfusion to neurons produces loss of both
pressure and deep pain sensations.
Physical findings include thin, shiny, and taut skin; loss of hair on the lower legs;
diminished or absent pedal, popliteal, or femoral pulses; pallor or blanching of the foot in
response to leg elevation (elevation pallor); and reactive hyperemia (redness of the foot)
when the limb is in a dependent position (dependent rubor).
Rest pain most often occurs in the forefoot or toes, is aggravated by limb elevation, and
occurs when there is insufficient blood flow to maintain basic metabolic requirements of
the tissues and nerves of the distal extremity.
Complications of PAD include nonhealing ulcers over bony prominences on the toes,
feet, and lower leg, and gangrene. Amputation may be required if blood flow is not
Tests used to diagnose PAD include Doppler ultrasound with segmental blood pressures
at the thigh, below the knee, and at ankle level. A falloff in segmental BP of more than 30
mm Hg indicates PAD.
Angiography is used to delineate the location and extent of the disease process.
The first treatment goal is to aggressively modify all cardiovascular risk factors in all
patients with PAD, with smoking cessation a priority.
Drug therapy includes antiplatelet agents and ACE inhibitors. Two drugs are approved to
treat intermittent claudication, pentoxifylline (Trental) and cilostazol (Pletal).
The primary nonpharmacologic treatment for claudication is a formal exercise-training
program with walking being the most effective exercise.
Ginkgo biloba has been found to increase walking distance for patients with intermittent
Critical limb ischemia is a chronic condition characterized by ischemic rest pain, arterial
leg ulcers, and/