Venous Insufficiency of the Lower Extremities – A Diverse Range of Risks, Manifestations, and Complications

Epidemiology and Risk Factors

Official statistics regarding the prevalence of chronic venous insufficiency (CVI) show considerable variability, which is due to the diversity of the population monitored, classification, or methodology. Generally, it can be said that varicose veins (with or without swelling) are found in about 25% of people. The main risk factors for this disease include older age, obesity, family history, and gender – it is slightly more common in women, especially pregnant ones. Anatomically, we distinguish between the superficial and deep venous systems; when we talk about CVI, it is almost always the superficial system, which includes the saphenous veins (mainly vena saphena magna and v. s. parva).

Pathogenesis

The pathogenesis of CVI is not clearly established, but it is described as reflux, obstruction, or a combination thereof. The main causes of venous reflux include valve insufficiency, inflammation of the vascular walls, hemodynamic factors, and venous hypertension. The condition may be further worsened by, for example, a dysfunctional pumping mechanism (in muscles or veins) in immobile patients or stiff joints.

It is not yet clear whether venous insufficiency is a result of inflammatory changes or precedes them. Venous hypertension and hemodynamic changes are associated with the release of vasoactive substances by the endothelium and the expression of adhesion molecules, chemokines, and inflammatory mediators. In the veins of patients with CVI, there is an increased amount of collagen and less elastin and laminin. The overall state of chronic inflammation thus leads to the clinical picture of CVI with lipodermatosclerosis and ulcers. Obstruction is then a result of thrombosis.

Clinical Manifestation

Patients often complain mainly of the following issues:

• feeling of heavy legs
• tendency to evening swelling
• itching
• pain
• nocturnal cramps in the lower extremities

The initial stages, i.e., C1 (telangiectasia, "spider veins") or C2 (varicose veins with a diameter > 3 mm without clinical symptoms), are not associated with any specific symptoms. Telangiectasia and reticular varices, usually around the ankles, are often the first warning signs of CVI. Telangiectasia are dilated intradermal veins with a diameter < 1 mm, while reticular varices are located subcutaneously and have a diameter of 1–3 mm. In both cases, it is more of a cosmetic issue, although it can also be painful.

In the next stage, i.e., C3, varicose veins develop. These are insufficiently functional subcutaneous veins with a diameter > 3 mm, and without treatment, their diameter increases significantly. In combination with swelling, which is initially spontaneously reversible overnight but can persist without treatment, the presence of varicose veins defines the onset of CVI. Venous hypertension leads to extravasation of erythrocytes and dermal deposition of hemosiderin, which is manifested by typical hyperpigmentation. Chronic swelling can lead to stasis dermatitis, characterized by erythematous, scaly, or occasionally itchy lesions on the lower part of the legs. In some cases, it may be confused with erysipelas or cellulitis.

Further progression of this condition leads to lipodermatosclerosis, which is caused by chronic inflammatory processes in the skin and subcutaneous tissue. Lipodermatosclerosis is associated with erythema, swelling, fibrosis, and pain and often results in venous ulcers.

Complications

Venous ulcers usually appear around the ankle and their complete healing requires long-term care for the resulting wound. Acute complications of CVI include thromboembolic events. In rare cases, superficial thrombophlebitis may develop, which manifests as an erythematous, soft, swollen, warm nodule or cord.

In about 18–25% of cases, it can also be associated with deep vein thrombosis or pulmonary embolism (7%). After deep vein thrombosis, up to 50% of patients develop post-thrombotic syndrome, i.e., obstruction of the deep venous system, possibly associated with valve insufficiency, venous hypertension, and pathological reflux.

Due to these poorly treatable complications, early diagnosis and adequate treatment of CVI are very important.

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Source: Santler B., Goerge T. Chronic venous insufficiency - a review of pathophysiology, diagnosis, and treatment. J Dtsch Dermatol Ges 2017; 15 (5): 538–556, doi: 10.1111/ddg.13242.