Arterial foot and leg ulcers are usually caused by arteriosclerosis obliterans (ASO), a progressive occlusive disease of the medium to large arteries. ASO is believed to begin by the formation of a fatty streak in the artery called atherosclerosis. These fatty streaks localize in the wall of the blood vessel and harden over time forming ASO. Complete occlusion of the artery results in disruption of blood flow to the target organ. In the case of a coronary artery, the end target organ is the heart and the result of arterial occlusion is a heart attack.

Arterial foot and leg ulcers occur in the same manner. Occlusion of the arteries of the leg impair healing resulting in ulcerations. Males are more predisposed to ASO. Other contributing factors include mechanical stress, lipid disorders and high blood pressure. Tobacco use, whether smoking, snuff or chew is a significant contributing factor. Circulating levels of nicotine make the blood more acidic. As a result, nicotine makes the artery wall much more permeable to atherosclerotic plaque, increasing the likelihood of ASO.

Wagner described the classification used to describe arterial ulcers and wounds used most commonly today.

Wagner Grade 1 Superficial wound with no infection. Skin is intact but erythematous.

Wagner Grade 2 Partial to full thickness erosion of the skin. Infection possible. No deep tissue or bone involvement.

Wagner Grade 3 Full thickness, deep tissue involvement. Wound is infected with probably bone infection.

Wagner Grade 4 Deep, extensive infection with gangrene.

Treatment of Arterial Foot and Leg Ulcers

The underlying cause of arterial foot and leg ulcerations is ischemia (lack of blood flow). Effective treatment of ischemia may include many different methods of care. Patients will benefit greatly from smoking cessation. Increased exercise may contribute to collateral circulation and may improve blood flow to the ulcer.

Several medications are used to improve arterial blood flow. Calcium channel blockers (Verapamil, Calan) may be used to increase small vessel peripheral blood flow. Trental has been available for several years. Trental coats the red blood cell so that it is slippery and able to travel through occluded vessels. Pletal became available in '00. Pletal (cilostazol) inhibits cellular phosphodiesterase. Recent studies have shown a significant reduction in intermittent claudication symptoms with Pletal.

Surgical revascularization is a common procedure but may only be used on the medium to large vessels of the leg.

Wound care is also important for arterial ulcerations. Treatment of infection any be necessary with antibiotics, whether topical, oral or IV. Protection of the wound is essential. Many devices have been invented for this purpose to act as a cradle or pad

Nomenclature:

Arteriole - a small artery

Arteriosclerosis obliterans - a progressive occlusive disorder of the veins and arteries due to atherosclerotic deposits

ASO - arteriosclerosis obliterans

Atherosclerosis - deposition of fat in the walls of an artery

Emboli - a term used to describe a blood clot

Spider veins - see telangectasia

Telangectasia - small, prominent surface capillaries and veins that are red or blue.

Venuole - a small vein

Symptoms:

Most patients with arterial leg ulcers are men over the age of 50 years. Their initial symptoms are suggestive of an occlusive vessel disease and include leg cramping at night and cramping when trying to walk a distance (intermittent claudication). Other symptoms may include fatigue of the leg, numbness or pain. Most symptoms are in the calf but may also occur in the thigh or buttocks.

As occlusion of the artery continues, symptoms will increase to include pain while the feet are elevated. Some patients find it more comfortable to sleep with the foot hung over the edge of the bed on the floor. Capillary refill time, the time it takes for a toe to 'pink up' after being held, becomes delayed. Pallor (whiteness) on elevation and rubor (redness) on dependency are classic findings.

Arterial ulceration may occur at any area where the arterial flow is compromised and typically these areas are areas of bony prominence such as the tip of a toe or ankle bone. Arterial ulcers commonly form as the result of continuous pressure on one focal area. This happens due to sleeping positions (side of ankle) or sitting positions (back of heel). Arterial ulcers usually begin as superficial lesions, are shallow and progress over time if the occlusive vessel disease is left untreated. Arterial ulcers are usually painful and may have a central area of necrotic (dead) debris. They are dry with little granulation tissue.

Differential Diagnosis:

ASO is a very common condition in men over the age of 50 years and should therefore be considered as the primary diagnosis in cases of arterial ulcers of the leg. Other possible conditions include;

Arterial embolism - an occlusive disorder due to a blood clot.

Burger's Disease - see thromboangitis obliterans.

Chronic venous ulcerations - typically moist and weeping at the medial distal leg.

Thromboangitis obliterans (TAO)- typically found in patients under the age of 40 years who are smokers. Found in the extremities. Characterized by intense inflammation of the walls of the vessels along with segmental occlusion. Inflammation extends to soft tissue surrounding the vessel leading to fibrosis of the extremity and eventual loss of fingers or toes.

Additional references include;

Roenigk, H.H., Young, J. R. Leg Ulcers, Medical and Surgical Management; Harper & Row Publishers, 1975
About the Author

Jeffrey A. Oster, DPM, C.Ped is a board certified foot and ankle surgeon. Dr. Oster is also board certified in pedorthics. Dr. Oster is medical director of Myfootshop.com and is in active practice in Granville, Ohio.