Peripheral Arterial Disease

Peripheral arterial disease (PAD) is most commonly caused by atherosclerosis  or hardening  of the arteries. This common affliction can go unnoticed for many years because it usually progresses slowly and onset of symptoms is gradual until it is finally diagnosed. The presence of  arterial insufficiency produces very specific symptoms and therefore diagnosis can often be made by a careful history and physical examination. Simply feeling for pulses can alert the physician to the presence of any significant artery blockages. Very often testing may be indicated to determine the severity and pattern of the disease and establish unequivocally if the symptoms you experience are due to PAD. Testing can be done non-invasively and consists of a variety of techniques that can measure the pressure and volume of blood in the affected limb. If this is abnormal, a complete overview of the circulation in the legs is most often made with ultrasound, a relatively inexpensive, completely safe and noninvasive technique that obtains pictures of the vessels and information about the blood flow in real time. No other technique provides both the anatomic and physiologic information which is of prime importance in PAD. 

How the lower extremity artery system works -

The arterial system is a series of branching vessels all originating from the heart—the central pump of the body. Similar to tree branches, the arteries become smaller and smaller as they extend to the periphery of the body. the aorta is the main artery that arises from the heart and gives rise to all other arteries. The abdominial aorta branches into the iliac arteries at the umbilicus or belly button. These in turn branch again and again until vessels course all the away to the abdomen.

ATHEROSCLEROSIS -

Normally the inner wall of an artery called the intima is smooth and elastic, allowing blood to flow freely. In vessels affected by atherosclerosis, the intima becomes thickened and rough by a build up cholesterol or fatty materials. This build up, much like rust in a pipe, is called plaque. As this plaque increases, it obstructs the opening or lumen of the blood vessel and may alter or limit the flow of blood. If the artery is severely narrowed, the amount of blood getting past can be so limited, that various symptoms can result. However, as long as this is a gradual process, the body is often very good at developing alternative pathways for blood flow called collaterals. 

SYMPTOMS - 

• Claudication  - leg pain with exercise is the classical symptom for lack of blood flow to the legs. An ache or cramp develops in the calf, thigh, or  buttocks when the muscle cannot get enough oxygen, Resting, even  for a short time, will allow the blood supply to “catch up” with the demand and symptoms subside. 
• Rest pain - severe and steady aching or pain, usually in the toes, heel, or foot, this suggests severe arterial disease. 
• Gangrene  - blood supply is insufficient to support the tissues and they begin to die ( tissue necrosis). 

There are other reasons why a person may experience leg pain with exertion or even at rest - commonly neuropathy or a nerve compression (neurospinal) syndrome. The testing equipment at QVI is well suited to determine with a high degree of certainty if pain is from a vascular cause (vasculogenic) or not.              

DIAGNOSIS - 

is typically done with a combination of  physiologic testing and duplex ultrasound (click for more on these testing procedures.) This non-invasive test can determine if disease is present, its severity, and if it is a likely source of your symptoms. We can also provide an overview of the arterial tree showing the pattern of disease. For example, it is important to know specifically where the disease is, if there is an isolated area of narrowing or is there diffuse disease throughout long segments, and if a vessel is severely narrowed of completely occluded. This information allows your physician to make specific recommendations as to the best way to treat your disease.

These ultrasound images show tibial arteries in the calf. The vessel on the left depicted in gray scale with the Doppler information displayed in color is widely patent and normal. In contrast, the vessel on the right shows a severe narrowing with the resultant flow disturbance.

The vessel on the left shows a flow limiting narrowing in the popliteal artery behind the knee - the main blood supply to the lower leg. The popliteal artery on the right reveals a large aneurysm with thrombus inside. While peripheral artery aneuryms rarely rupture, they are potentially quite dangerous if they shower this thrombus to the lower leg. 

TREATMENT -

• Modify risk factors - Patients with disease can dramatically lessen the likelihood of the narrowing becoming worse. Stop smoking, control blood pressure, blood sugar, and cholesterol levels, maintain proper weight and diet.

• Exercise - Most importantly, a regular exercise regimen can build collaterals and actually reduce the severity of the symptoms. Experience shows walking a loop is a useful method. Choose a distance where you get the pain a few minutes before you finish. Remember, you must walk some distance with the pain to get maximum benefit. Then gradually try to lengthen the loop. Regularly walk short or moderate distances, instead of longer distances sporadically. Regularity is key!

• Follow-up - This can usually be done clinically. “Are you walking farther without pain?” If necessary, the severity of the plaque buildup can be followed by ultrasound and / or physiologic testing to determine if there is any progression of disease.

• Medicine - While medicine will generally not lessen the plaque, there are several medications that may be prescribed to aid in modifying risk factors or reduce symptoms.

• Endovascular Intervention - There are a multitude of “minimally invasive” options to treat blockages. Most common is balloon angioplasty with a stent inserted to hold the artery open.

• Surgery - If blockages are too extensive, bypass surgery can be done to get blood to the affected area. A vein from the leg or arm or a synthetic tube can be used to bypass the blocked artery. This is usually done for rest pain or gangrene.

Here is a great link from the Society of Vascular Surgery that thoroughly outlines the all the options -   Society of Vascular Surgery