Chronic Venous Insufficiency

Introduction

Essentials of Diagnosis

• History of phlebitis or leg injury.
  
• Ankle edema is the earliest sign.
  
• Late signs are stasis pigmentation, dermatitis, subcutaneous induration, varicosities, and ulceration.

General Considerations

Chronic venous insufficiency is most often secondary to DVT, although a history of phlebitis is not obtainable in about 25% of patients. Other possible causes are leg trauma, varicose veins, neoplastic obstruction of the pelvic veins, or congenital or acquired arteriovenous fistula.

The basic physiologic abnormality in patients with chronic venous insufficiency is chronic elevation in venous pressure. The normal venous capacitance can accommodate large-volume changes that occur during exercise with only minimal changes in venous pressure. However, when valves in the deep or perforating veins are destroyed by thrombophlebitis, valvular reflux and bidirectional blood flow result in abnormally high ambulatory venous pressures. Proximal venous obstruction also results in venous hypertension. High ambulatory venous pressure transmitted through perforating veins of the calf and ankle results in superficial varicosities, edema and fibrosis of the subcutaneous tissue and skin, hyperpigmentation, and, later, dermatitis and ulceration.

Clinical Findings

Chronic venous insufficiency is characterized by progressive edema of the leg that begins at the ankle and calf and is accompanied by a dull aching discomfort. Typically, the edema is worst at the end of the day and improves with leg elevation. Varicosities are often present. Stasis dermatitis, brownish pigmentation, brawny induration, and ulceration develop with long-standing disease. The skin is usually thin, shiny, atrophic, and cyanotic. Cellulitis may appear in scaly, dry, itchy regions with skin breakdown; in other areas, a weeping dermatitis may develop. Venous stasis ulcers are large, painless, and irregular in outline. They have a shallow, moist granulation bed and occur in the gaiter area on the medial or lateral aspects of the ankle. Healing of these ulcers results in a thin scar on a fibrotic base that often breaks down with minor trauma.

Differential Diagnosis

Congestive heart failure and chronic renal disease may result in bilateral edema of the lower extremities. Lymphedema is associated with a brawny thickening in the subcutaneous tissue that does not respond readily to elevation; edema is particularly prominent on the dorsum of the feet and in the toes; varicosities are absent, and there is often a history of recurrent cellulitis.

Primary varicose veins or acute DVT may be difficult to differentiate from chronic venous insufficiency without diagnostic tests.