Similar to the other vessels in the circulatory system, the vein walls are composed of three layers. The innermost layer of epithelial tissue is the tunica intima, the tunica media is the middle layer, and the outer layer is the tunica externa. The tunica externa is made up of collagen and elastic fibers and is the thickest layer of the vein walls [3].

Veins in the legs are divided into three major groups based on their relationship to the muscular fascia: deep veins, superficial veins, and perforator veins [5]. The deep venous system consists of the posterior and anterior veins and includes the common iliac veins, the femoral veins, and the popliteal veins [3]. These veins are located under the muscular fascia inside the muscle compartments of the leg, usually in close proximity to their companion arteries [5]. However, there is considerable variability in individual anatomy [6]. The deep veins are responsible for draining blood from the lower extremity muscles.

Among these three pumps, the calf pump is the most important and is responsible for the greatest pressures [6]. During ambulation, this pump is responsible for propelling 70% of the blood out of the calf [8]. When the calf muscle pump contracts, blood is pushed out of the veins and the resting pressure in the veins decreases. Because blood flows from areas of high pressure to areas of low pressure, this decrease in the pressure gradient in the deep venous system after contraction allows blood to flow from the superficial veins to the deep veins via the perforating veins [6]. As long as the valves of the venous system are functioning correctly, there is little retrograde blood flow [9].

There is some evidence that chronic venous insufficiency is more common in white individuals than in racial/ethnic minorities [16,17]. However, when present, venous disease in black patients is more likely to present at a more advanced stage at a younger age compared with white patients, resulting in increased ulcer debridement, deep vein thrombosis rates, and hospital charges [17].

When taking a patient history, it is important to explore risk factors for lower extremity venous disease [9]. Some of the more common prevailing risk factors are [5]:

There are two forms of edema: pitting and non-pitting. Non-pitting edema presents as a swollen area that is hard to the touch. With pitting edema, pressure in the swollen area results in a persistent indentation. Pitting edema around the ankle that worsens through the day is a typical finding in advanced venous disease.

Stasis dermatitis, also known as venous dermatitis or venous eczema, is dry, scaling skin of the lower extremities [18]. The first presentation is a reddish-brown skin discoloration, typically of the medial ankle. As the disease progresses, eczematous changes may be present, with weeping patches and plaques. Stasis dermatitis is often the first and most common skin change associated with venous disease. It is extremely pruritic (with insidious onset), which is a source of significant discomfort for patients.

Lipodermatosclerosis is an inflammation and hardening of the subcutaneous fat and dermal tissue found in longstanding venous insufficiency. It is caused by protein accumulation in the tissues, most noticeably in the "gaiter area" of the leg (between the knee and ankle) [18]. Lipodermatosclerosis presents as hard, waxy, hyperpigmented tissue with swelling of the surrounding areas. This has given rise to the description of a "bottle leg" formation [18].

During the physical examination, the femoral and pedal pulses should be assessed. The pedal pulses include the dorsalis pedal pulses, located between the first (great) toe and the second toe on the dorsum of the foot, and the posterior tibial pulse, located behind the medial malleolus. In younger patients, it may be possible to palpate these pulses; however, in older patients, use of a handheld Doppler is often necessary to detect a pulse beat [22].

It has been documented that individuals with venous disease and those who progress to venous ulceration have higher skin temperatures around the ankle than the general population [5]. A sudden elevation in temperature more than 4 degrees Fahrenheit may be indicative of a developing leg ulcer [5].

Venous ultrasound is an important tool to determine the source of venous insufficiency [18]. A duplex ultrasound is used to locate malfunctioning perforator veins that may exist between the superficial and deep veins [10]. The American College of Phlebology has also recommended assessment of the patency and competency of the common femoral and popliteal veins [25]. Duplex ultrasound is regarded as the most reliable noninvasive test for diagnosing venous insufficiency [5].

All patients with venous insufficiency should have ankle-brachial index (ABI) studies done regularly, usually every three months [5]. The ABI is a noninvasive, indirect measurement of arterial blood flow to the lower extremities. Approximately 26% of those with venous problems also have arterial insufficiency, and the ABI value will help determine if the diagnosis is severe arterial disease, mixed arterial and venous pathology, or primarily venous disease [26,27]. An ABI value greater than 0.8 indicates primarily venous disease, while a value of 0.5–0.8 suggests a mixed etiology [24]. An ABI value less than 0.5 points to severe arterial disease, and compression therapy is not recommended for these patients [5].

ABI testing is done by comparing the systolic blood pressures in the ankle to the systolic brachial blood pressures [28]. When obtaining an ABI reading, start by explaining the procedure to the patient and allowing him or her to rest in the supine position. The most accurate results are obtained when the patient is relaxed in a comfortable position with an empty bladder [26]. After about 15 minutes, take brachial blood pressure readings in both arms; the higher of the systolic pressure readings will be used to calculate the ABI value.

Venous ulcers normally develop on the medial malleolus, ankle, or posterior calf; over a perforating vein; or along the route of the great or small saphenous veins. They do not occur above the knee or in the area of the forefoot [20,22]. In appearance, the ulcers are usually irregular and shallow, with granulation tissue and fibrin evident in the wound bed [11].

If a venous ulcer has not yet developed, the primary goal of treatment of chronic venous insufficiency is to reduce venous hypertension and prevent ulceration. The plan of care for these patients will include weight management, compression therapy, leg elevation, setting realistic goals to become more physically active, and patient education. If an ulcer is present, the goal is to achieve complete healing and prevent ulcer reoccurrence.

The Unna boot provides inelastic compression, meaning that the pressure gradient is high while the patient is walking but low (or lacking) when the patient is resting. As such, multilayer compression bandages may supply more effective compression for non-ambulatory patients than the Unna boot. The Unna boot also does not adapt to changes in the patient's leg size, which can lead to complaints of pain and discomfort [11].

The degree of compression therapy can be categorized as light, moderate, or high [5]. Light compression applies 20–30 mm Hg of pressure to the ankle area and is recommended for patients with venous insufficiency who are unable to tolerate higher levels of compression. Approximately 35–40 mm Hg of compression (moderate) is regarded as the most appropriate level for venous ulcer wound healing. A high level of compression is obtained with a pressure gradient of 40–50 mm Hg. As noted, there is strong evidence that approaches that achieve higher levels of compression (i.e., 35 mm Hg or greater), including multilayer elastic systems, achieve the best healing outcomes [9].

Compression stockings are available in most large stores or pharmacies or mail ordered from several companies and can be worn with the patient's normal footwear. Patients and caretakers should be advised to buy at least two pairs of stockings to facilitate washing and drying. Manufacturer instructions should be followed for washing, but in most instances, hand-washing and air-drying are preferred. Lower levels of compression are better than no compression at all or stockings that are "left in the drawer" [9]. However, patients should be informed that nonmedical support hosiery and anti-embolism stockings (with a pressure gradient of 8–18 mm Hg) are not suitable for compression therapy and were not made for this purpose [5].

The major drawback is that people may find it difficult to don the stockings independently, especially if they have arthritis or neurologic deficits. There are stockings available with a side zipper that makes them easier to apply and remove, although they may be more expensive. It is also possible to purchase an inner silk lining sleeve to facilitate sliding the compression stocking on and off. Several brands of compression stockings also come with a wide band at the top, which provides a better grip [10]. Some people find that wearing rubber gloves helps to get the stockings on easily, but others do not find this helpful.

Bioengineered therapy in conjunction with compression therapy is an option for the treatment of venous ulcers that have not healed after 30 days [30]. Single-layered and bilayered bioengineered skin cellular substitutes do not provide a graft covering to the wound, but rather donate multiple growth factors to the wound bed to stimulate healing [24]. The Wound Healing Society states that bilayered artificial skin in conjunction with compression therapy is better than compression and a simple dressing [41].

Patients with venous ulcers and their caregivers should be taught how to assess the wound with each dressing change done in the home. This should include the signs of wound infection, such as changes in the amount of wound drainage, odor, and the color of the wound bed (e.g., changing from a bright red to a dark ruddy color). Changes in the periwound area, including alterations in appearance, swelling, tenderness, and pain level, are also important to note. The occurrence of any of these symptoms should prompt the patient and/or caregiver to contact his or her physician immediately.

An honest discussion should be held with the patient and significant others about what treatment is going to entail, including the necessity for weekly visits to the wound clinic for debridement and dressings changes. If a patient has difficulty keeping appointments, treatment will not be successful and healing may not be achieved.

It is vital to listen carefully to patients' concerns about treatment. Patients may be worried about missing work, transportation to appointments, wound care at home, and/or the cost of supplies. All members of the team caring for the patient should be aware of the concerns and support the patient to explore solutions. The input of the team social worker and/or case manager is particularly important at this time.

Many individuals with venous disease do not have sufficient knowledge to manage their condition successfully in the long term. The focus should be extended beyond wound healing and to making changes to maintain a healthy lifestyle. If a patient smokes, the benefits of smoking cessation for wound healing should be discussed. Weight management, safe exercise (e.g., walking), and prevention of trauma to the lower extremities should be explored with the patient/family. Concrete suggestions are better than general recommendations. For example, a patient may be instructed to take a brisk walk every day, not to cross his/her legs, and not to stand for more than 30 minutes at a time.