Chronic venous insufficiency: causes, symptoms, diagnosis, treatment

Chronic venous insufficiency is an altered venous outflow, sometimes causing discomfort in the lower limb, swelling and skin changes. Postphlebitic (postthrombotic) syndrome is a chronic venous insufficiency accompanied by clinical symptoms. The causes are disorders that lead to venous hypertension, usually damage or insufficiency of venous valves, which occurs after deep vein thrombosis (DVT). Diagnosis is established by collecting anamnesis, using physical examination and duplex ultrasonography. Treatment includes compression, injury prevention and (sometimes) surgical intervention. Prevention includes treatment of deep vein thrombosis and wearing compression stockings.

Chronic venous insufficiency affects 5% of people in the United States. Postphlebitic syndrome may occur in 1/2 to 2/3 of patients with deep vein thrombosis, usually within 1 to 2 years after acute deep vein thrombosis.

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Causes of chronic venous insufficiency

Venous drainage from the lower extremities is accomplished by contraction of the calf muscles to force blood from the intramuscular (plantar) sinuses and gastrocnemius veins into the deep veins. Venous valves direct blood proximally toward the heart. Chronic venous insufficiency occurs when venous obstruction (eg, in deep vein thrombosis), venous valvular insufficiency, or decreased contraction of the muscles surrounding the veins (eg, due to immobility) occurs, decreasing venous flow and increasing venous pressure (venous hypertension). Long-term venous hypertension causes tissue swelling, inflammation, and hypoxia, leading to symptoms. Pressure may be transmitted to the superficial veins if the valves in the perforating veins, which connect the deep and superficial veins, are ineffective.

Deep vein thrombosis is the most common known risk factor for chronic venous insufficiency, with trauma, age, and obesity also contributing. Idiopathic cases are often attributed to a history of silent deep vein thrombosis.

Chronic venous insufficiency with clinical symptoms following deep vein thrombosis resembles postphlebitic (or postthrombotic) syndrome. Risk factors for postphlebitic syndrome in patients with deep vein thrombosis include proximal thrombosis, recurrent unilateral deep vein thrombosis, overweight (BMI 22-30 kg/m2), and obesity (BMI > 30 kg/m2). Age, female sex, and estrogen therapy are also associated with the syndrome but are probably nonspecific. Use of compression stockings after deep vein thrombosis reduces the risk.

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Symptoms of chronic venous insufficiency

Chronic venous insufficiency may cause no symptoms, but always has characteristic manifestations. Postphlebitic syndrome always causes symptoms, but may not have noticeable manifestations. Both disorders are worrisome because their symptoms can simulate those of deep vein thrombosis, and both can lead to significant limitations in physical activity and a decrease in quality of life.

Symptoms include a feeling of fullness, heaviness, pain, cramps, fatigue, and paresthesia in the legs. These symptoms are aggravated by standing or walking and are relieved by rest and by raising the legs. Itching may accompany skin changes. Clinical symptoms gradually increase: from no changes to varicose veins (sometimes) and then to stasis dermatitis of the shins and ankles, with or without ulceration.

Clinical classification of chronic venous insufficiency

Class	Symptoms
0	No signs of venous damage
1	Dilated or reticular veins*
2	Varicose veins*
3	Edema
4	Skin changes due to venous congestion (pigmentation, stasis dermatitis, lipodermatosclerosis)
5	Skin changes due to venous stasis and healed ulcers
6	Skin changes due to venous stasis and active ulcers

* May occur idiopathically, without chronic venous insufficiency.

Venous stasis dermatitis presents with reddish-brown hyperpigmentation, induration, varicose veins, lipodermatosclerosis (fibrosing subcutaneous panniculitis) and venous varicose ulcers. All of these features indicate long-standing, persistent disease or more severe venous hypertension.

Venous varicose ulcers may develop spontaneously or after the affected skin is scratched or injured. They typically occur around the medial malleolus, are shallow and oozing, and may be foul-smelling (especially if poorly cared for) or painful. These ulcers do not penetrate the deep fascia, unlike ulcers due to peripheral arterial disease, which eventually involve tendons or bone.

Leg swelling is most often unilateral or asymmetrical. Bilateral, symmetrical swelling is more likely to indicate a systemic disease (eg, heart failure, hypoalbuminemia) or the use of certain medications (eg, calcium channel blockers).

If the lower extremities are not carefully cared for, patients with any manifestation of chronic venous insufficiency or postphlebitic syndrome are at risk of the disease progressing to a more severe form.

Diagnosis of chronic venous insufficiency

Diagnosis is usually based on history and physical examination. The clinical scoring system, which takes into account five symptoms (pain, cramp, heaviness, pruritus, paresthesia) and six signs (edema, hyperpigmentation, induration, varicose veins, redness, pain on compression of the calf), ranges from 0 (absent or minimal) to 3 (severe). It is increasingly accepted as a standard diagnostic method. A score of 5-14 on two examinations performed more than 6 months apart indicates mild to moderate disease, and a score > 15 indicates severe disease.

Duplex ultrasonography of the lower extremity helps to exclude deep vein thrombosis. The absence of edema and a reduced ankle-brachial index distinguish peripheral arterial disease from chronic venous insufficiency and postphlebitic syndrome. The absence of pulsation in the ankle joint suggests peripheral arterial pathology.

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Prevention and treatment of chronic venous insufficiency

Primary prevention involves anticoagulant therapy after deep vein thrombosis and the use of compression stockings for 2 years after deep vein thrombosis or venous injury of the lower extremity. Lifestyle changes (eg, weight loss, regular exercise, reduction of table salt intake) also play an important role.

Treatment includes elevation of the leg, compression with bandages, stockings, and pneumatic devices, care of skin lesions, and surgery depending on the severity of the condition. Drugs have no role in the routine treatment of chronic venous insufficiency, although many patients are given aspirin, topical glucocorticoids, diuretics to reduce swelling, or antibiotics. Some experts believe that weight loss, regular exercise, and a reduction in dietary salt may be beneficial for patients with bilateral chronic venous insufficiency. However, these measures are difficult to implement for many patients.

Elevating the leg above the level of the right atrium reduces venous hypertension and edema, which is suitable for all patients (this should be done at least 3 times a day for 30 minutes or more). However, most patients cannot maintain this regimen throughout the day.

Compression is effective for the treatment and prevention of chronic venous insufficiency and postphlebitic syndrome and is indicated for all patients. Elastic bandaging is used first until the swelling and ulcers have resolved and the leg size has stabilized; then ready-made compression stockings are used. Stockings that provide a distal pressure of 20-30 mm Hg are prescribed for small varicose veins and moderate chronic venous insufficiency; 30-40 mm Hg for large varicose veins and moderate severity of the disease; 40-60 mm Hg and more for severe disease. Stockings should be put on immediately after waking up, before leg swelling increases due to physical activity. Stockings should provide maximum pressure in the ankle area and gradually reduce the pressure proximally. Compliance with this treatment modality varies: many younger or active patients find stockings irritating, restrictive, or cosmetically unsightly; older patients may have difficulty putting them on.

Intermittent pneumatic compression (IPC) uses a pump to cyclically inflate and deflate hollow plastic gaiters. IPC provides external compression and forces venous blood and fluid up the vascular bed. It is effective in severe postphlebitic syndrome and venous varicose ulcers, but may be comparable in effect to wearing compression stockings.

Skin care is very important for venous stasis ulcers. Almost all ulcers heal with the application of an Unna boot (a zinc oxide impregnated dressing) covered with a compression bandage and changed weekly. Compression devices [eg, hydrocolloids such as aluminum chloride (DuoDERM)] provide a moist environment for wound healing and stimulate new tissue growth. They can be used to treat ulcers to reduce exudation, but are likely to be little more effective than a regular Unna dressing and are expensive. Regular dressings are absorbent, which may be helpful for more severe exudations.

Drugs have no role in the routine treatment of chronic venous insufficiency, although many patients are given aspirin, topical glucocorticoids, diuretics to reduce edema, or antibiotics. Surgical treatment (eg, vein ligation, stripping, valve reconstruction) is also generally ineffective. Autologous skin grafting or skin created from epidermal keratocytes or dermal fibroblasts may be an option for patients with resistant venous ulcers when all other measures have failed, but the graft may reulcerate if the underlying venous hypertension is not corrected.