Leg pain can occur for a variety of reasons but when it is caused by a loss of circulation resulting from arterial blockages, it is referred to as peripheral arterial disease (PAD). PAD is a slowly developing condition where cholesterol and fatty deposits develop within the wall of the artery. This process is also known as plaque formation or atherosclerosis. Areas of plaque cause an inflammatory reaction within the arterial wall and often will lead to an accumulation of calcium within the plaque. As plaque builds up, it causes a progressive narrowing of the artery flow channel. When the flow channel becomes over 50% narrowed, blood flow is reduced to the point where symptoms begin to occur.
Symptoms of PAD are most commonly leg pain with exertion, or claudication. The pain tends to occur in muscle groups located down stream from the area of blockages. Typically the obstructed areas are identified one joint level above the muscles which are painful. Arterial blockages in the abdomen or pelvis commonly are associated with pain in the hip or buttocks while those of the groin or thigh cause pain and cramping in the calf muscles. The reason one gets pain with PAD is that exercise induces the smaller blood vessels to dilate. When the artery supplying the leg is significantly narrowed then the blood supply to the muscle groups is not sufficient to meet the demand. As a result, muscle pain occurs much in the same way one can get angina in the heart. The pain is relieved by resting and usually after stopping for a few minutes, one can resume walking. These symptoms are reproducible and can be brought about quicker or made worse by walking faster, up stairs, or uphill. If the arterial flow channel becomes obstructed abruptly or in multiple areas, then the patient may experience leg pain while at rest. This is usually quite severe and occurs more commonly in the foot and lower leg. In addition, the foot may appear pale or white, feel cold or numb. Rest pain, if untreated, can lead to gangrene or limb loss.
PAD can usually be detected through a careful history and physical examination by your physician. Additional testing is usually performed to confirm the presence of PAD and identify the exact locations of the obstructions. Non-invasive testing typically begins with measuring the ankle – brachial index (ABI). In this test, blood pressures are taken in both the arms and the ankles and compared to each other (ankle over arm) A ratio above 0.9 is considered normal range while ratios below 0.9 marking the presence of PAD. ABIs below 0.5 usually indicate more severe disease such as rest pain and those at highest risk for limb loss. Arterial ultrasound examinations are also performed which can specifically identify the location and severity of the arterial blockages.
The treatment for PAD depends on the degree of disability created by the arterial blockage. Most patients are initially managed with medical therapy. This includes a graded exercise program, smoking cessation, risk factor modification, in addition to antiplatelet therapy such as aspirin, or other agents such as Pletal or Trental. While medical therapy does not reduce the size of the blockages themselves, it retrains the affected muscle groups to work more efficiently with less fuel, thereby reducing the patients symptoms. Life style modification such as smoking cessation, weight loss, and low fat diet are important adjuncts in decreasing one’s associated cardiovascular risk. With medical therapy, most patients can double their pain free walking distance within 12 months.
For patients with more disabling or severe PAD symptoms as well as those with limb threatening ischemia, more invasive testing with angiography is needed. Symptomatic obstructions unresponsive to medical therapy or advanced arterial disease require treatments that actively provide improved blood flow into the limb. Angioplasty and stenting can be used to effectively re-open areas of arterial obstruction and improve limb blood flow. If the areas of blockage are extensive or heavily calcified, removing the offending plaque itself (endarterectomy) or surgical bypass may be required to reroute blood around the blocked arterial segment.
The physicians at EvergreenHealth Heart & Vascular Care are trained in all aspects of arterial reconstructions, from the latest minimally invasive interventional techniques to the most complex surgical bypass procedure. Our goal is to provide an individual solution to each patients specific needs, using the most appropriate techniques to provide the best outcome with the least amount of risk.