Chronic disturbances of venous blood flow are associated with vein dilation, functional impairment of vascular walls and surrounding tissues as well as local inflammation. Minor trauma to affected tissues may result in poor wound healing and venous stasis ulcer.
Venous stasis primarily occurs in body regions situated below the heart. Granulation tissue is often visible at the base of the ulcer. For physical reasons, the lower legs are most frequently affected. Ulcers are commonly situated over bony prominences because these sites are more prone to trauma. Still, patients may not associate a VSU with any traumatic event. They are irregularly shaped, shallow cutaneous lesions of varying size. Edematous swelling, erythema and shiny skin consistent with stasis dermatitis may be noted in close proximity to VSU . Lipodermatosclerosis and atrophie blanche are commonly observed . Patients may claim tenderness and dull aching pain in regions affected by VSU. In the case of systemic disorders, symptoms occur bilaterally. In contrast, post-traumatic VSU and similar conditions are generally limited to one leg.
Leg ulcers are very common and are diagnosed clinically. Anamnestic data generally support the diagnosis of VSU. Because these ulcers occur in patients suffering from chronic disease, affected individuals typically have a medical history of venous insufficiency, varicose veins, phlebitis and/or eczematous dermatitis. Complaints associated with these pathologies subside when the legs are elevated.
In case of doubt, further measures are required to distinguish VSU from ulcers resulting from arterial disorders and vasculitis :
It is important to note that malignancies may develop from chronic wounds like VSU . In this context, biopsy specimens should be obtained for histopathological and immunohistochemical analyses.
Venous blood flow depends on the activity of the surrounding musculature as well as cardiac function :
Both venous insufficiency and cardiovascular disease - often occurring concomitantly - may thus result in venous hypertension and blood stasis. Moreover, venous stasis may be related to a mechanical obstruction of veins, as is the case in patients suffering from vein thrombosis. Less common causes of venous stasis include phlebitis, malignancy , post-traumatic formation of an arteriovenous fistula , and congenital malformations , among others.
Venous stasis may affect superficial veins, a common condition known as varicose veins, or deep veins. In any case, chronic venous stasis leads to structural changes in venous walls and surrounding tissues. It has been suggested that fibrin leakage may result in the development of perivascular fibrinogen cuffs that hinder the passage of oxygen, nutrients and a variety of other molecules to dependent tissues. In the case of a traumatic lesion, this condition would largely impair wound healing and predispose for the onset of venous stasis ulcer (VSU). Of note, other hypotheses have been proposed regarding the pathogenesis of VSU .