Understanding the differences between arterial and venous ulcers is important in the effective treatment of lower leg and foot wounds. Determining the type of vascular wound you are dealing with can save vast amounts of time in the healing process. Let’s look at some of those differences and how to treat each type.
Venous ulcers
According to the National Library of Medicine, venous leg ulcers are the most common type of lower leg wound and are more common in women than men. Venous ulcers are an indication of venous insufficiency in the lower leg vasculature. Risk factors for developing venous insufficiency include obesity, smoking, lack of exercise, standing or sitting for prolonged periods of time, a family history of venous problems, pregnancy, and a history of injury, surgery, or blood clots in the lower leg.
These factors can cause the valves of the veins to malfunction resulting in poor blood flow back to the heart. Signs of venous insufficiency in the lower legs include pain, swelling, varicose veins, heaviness, open wounds, weeping, and skin color changes.
Venous ulcers are normally located on the lower leg above the ankle. They are shallow ulcers with uneven edges. They may have necrotic tissue such as slough present in the wound bed. Venous ulcers typically have serous or serosanguineous drainage and are often painless or only mildly painful.
The surrounding skin may look dark compared to the skin over the rest of the leg. This dark staining is called hemosiderin staining and is due to hemoglobin from red blood cells being released into the tissues. Ankle Brachial Index readings are typically in the normal range with venous disease.
Venous insufficiency may be diagnosed by a medical exam along with a person’s medical history. A venous reflux ultrasound can confirm this diagnosis and will show the actual areas of obstruction or incompetence within the venous system. This tool is useful for a provider to determine pathways of treatment of the venous insufficiency.
Venous ulcer treatment
Treatment of a venous ulcer includes cleansing the ulcer and choosing a type of dressing that will control the drainage. Compression of the lower leg is essential for healing to take place. This compression helps move the pooled blood, improves drainage of the lower leg, and reduces associated pain and swelling. Compression is achieved by the use of wraps, bandages, or stockings. Ideally, compression wraps are placed and changed once or twice weekly during the duration of wound treatment. Once the wound has healed, transitioning to a daily compression stocking is necessary for the prevention of future ulcers.
Patients should be taught to wear their compression stockings daily, removing at night and replacing first thing in the morning. Patients should also be educated on the benefits of exercise, lower leg elevation, and a low sodium diet as lifestyle changes necessary for maintenance of venous insufficiency. Without these daily modifications, patients with venous insufficiency can expect to have ongoing issues with leg ulcers.
Referral to a vascular surgeon may be necessary for patients with confirmed venous insufficiency whose wounds are not responding to conventional treatment of wound dressings and compression. Surgical procedures, such as vein ablation, may be necessary to treat more significant venous disease.
Arterial ulcers
Narrowing or blockages in the arteries to the lower leg and foot contribute to the formation of arterial ulcers. Risk factors for atherosclerosis leading to arterial ulcer formation include advanced age, smoking, obesity, diabetes, renal insufficiency, sedentary lifestyle, hypertension, dyslipidemia, and family history. Reduced blood flow keeps necessary nutrients and oxygen from the tissues of the lower leg and foot. This lack of nutrients contributes to the breakdown of skin.
Signs of poor perfusion to the lower leg include mottled or dusky colored skin, coolness to touch, poor capillary refill, lack of hair to the lower leg, weak or no palpable pulse, tight/shiny skin, and pain. Patients with poor arterial flow usually have pain with walking and exercise.
Elevating the lower legs may cause an increase in pain. Advanced arterial disease patients may have pain even at rest and will often sleep with the affected leg dangling over the edge of the bed. This dependent position uses gravity to help bring as much blood flow as possible to the lower leg, thereby decreasing the pain.
Patients with arterial disease will have a lower-than-normal Ankle Brachial Index reading. A patient with poor arterial perfusion that sustains an injury to the lower leg is at risk of developing an arterial ulcer. Also, patients with wounds of the lower leg or foot that are not showing signs of healing should be assessed for arterial compromise.
Arterial ulcers often look like they are “punched out” of the skin. They have even, well-defined edges and are often deep. Support structures such as tendon and ligament may be exposed. There is typically unhealthy, dry tissue in the wound bed and necrotic tissue is often present. The toes, heel, and outer ankle are common areas for arterial ulcers to develop.
Arterial disease may be diagnosed by a medical exam and medical history. An arterial duplex can confirm the diagnosis and will show the areas of stenosis or obstruction. This is useful to help guide treatment.
Arterial ulcer treatment
Treatment of an arterial ulcer consists of creating a moist healing environment, preventing infection, and reducing pain. A referral to a vascular surgeon is often necessary. Procedures such as angioplasty and stenting are often needed to restore blood flow to the lower leg and foot.
A patient with significant stenosis is unlikely to achieve wound healing without a procedure such as these. In the most severe cases, or in the presence of a gangrenous infection, amputation of the digit or limb is likely.
Mixed disease
It is quite common for a patient to exhibit signs of both venous and arterial disease. A physical exam and diagnostic testing can determine which of these is the most significant. The initial course of treatment should follow the more extensive disease.
When differentiating between a venous and arterial ulcer, it is often helpful to imagine liquid being poured over the ulcer. Will that liquid slide right down the leg or will it pool in the ulcer? If it seems more likely that the liquid will pool, chances are the ulcer has a significant arterial component.
Differentiating between venous and arterial ulcers takes a little practice and time, but your patients will benefit from your ability to make the correct diagnosis as early in their treatment as possible.
Want to learn more about arterial ulcers or venous ulcers? Take WCEI's Skin and Wound Management course and elevate your expertise in wound care.
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