Venous thromboembolic disease

Thrombosis can occur in any vein, but the veins of the leg and pelvis are the most common sites.

Risk factors for venous thromboembolism:

• Increasing age
• Obesity
• Varicose veins
• Immobility (bedrest >4 days)
• Pregnancy
• OCP
• Previous DVT
• Thrombophilia
• Trauma/surgery
• Malignancy
• Infection

Superficial thrombophlebitis:

• Commonly involves the saphenous vein
• Often associated with varicosities
• Occasionally the axillary vein is involved (usually as a result of trauma)
• Local, superficial inflammation of the vein wall, with secondary thrombosis
• The clinical picture is of a painful, tender, cord-like structure with associated redness and swelling
• Treatment:
• Rest
• Elevation of the limb
• Analgesics (e.g. NSAIDs)
• Anticoagulants are NOT necessary as embolism does not occur from superficial thrombophlebitis

Deep vein thrombosis (DVT):

• Thrombosis commonly occurs after periods of immobilization, but it can occur for apparently no reason
• A DVT in the leg occurs in 50% of patients after prostatectomy or following a CVA
• 30% of patients with a MI have a DVT
• Thrombosis can occur in any vein of the leg but it is particularly found in the veins of the calf
• Is often asymptomatic

Clinical features of a DVT:

• Asymptomatic
• Calf DVT:
• Pain
• Redness
• Swelling
• Engorged superficial veins

• Iliofemoral DVT:
• Severe pain
• Thigh swelling
• Ankle oedema

PE can occur with any DVT but is more frequent from an iliofemoral thrombosis and is rare with thrombosis confined to veins below the knee

Investigations of DVT:

• Doppler ultrasound
• Venography

Treatment:

• All patients with thrombi above the knee are anticoagulated
• Anticoagulation of below-knee thrombi is controversial but is usually recommended for 6 weeks
• Heparin is usually given for 2-3 days whilst warfarin (which is started immediately) becomes effective
• Target INR should be 2.5
• Warfarin is usually continued for 3 months
• Thrombolytic therapy is sometimes used for patients with a large iliofemoral thrombosis

Prognosis:

• Approximately 50% of patients with a DVT will have destruction of the deep vein valve. This produces a:
• Clinically painful, swollen limb
• Made worse by standing
• Oedema
• Venous eczema
• Elastic support stockings are required for life