PERIPHERAL VENOUS DISEASE



The most common disorder involving the pe­ripheral veins is venous thrombosis and throm­bophlebitis. Thrombophlebitis refers to inflam­mation of the vein, usually from thrombus but occasionally from trauma or infection. Predispos­ing factors to thrombophlebitis are venous stasis, local venous injury, and hypercoagulable states. Particular risk factors for thrombophlebitis in­clude oral contraceptives, trauma or fractures of the extremities, pregnancy, major surgery, pro­longed immobilization, heart disease, varicose veins, and myeloproliferative syndromes. Local thrombophlebitis may occur from administration of irritating drugs such as chemotherapeutic agents or from indwelling intravenous catheters, especially if infection has supervened (septic phlebitis). Patients with malignancies appear to be prone to migrating, recurrent thrombophlebi­tis. Thrombophlebitis can occur with thromboan­giitis obliterans or processes causing extrinsic ob­struction of venous flow. In some patients no predisposing factors can be found. Low-dose sub­cutaneous heparin appears to be effective pro­phylaxis against deep vein thrombosis in patients with a variety of medical or surgical conditions.

Symptoms and signs of venous thrombosis and thrombophlebitis in the leg vary. The onset may be inapparent until pulmonary embolism occurs. Warmth and edema may occur, and the affected leg may become larger than the other. Tenderness over the deep vein upon palpation or inflation of a blood pressure cuff may be noted. Pain upon dorsiflexion of the foot (Homans’ sign) is neither sensitive nor specific. Skin changes such as mot­tling or cyanosis may be present. A palpable ven­ous “cord” occurs in only about 20 per cent of patients. When thrombophlebitis is superficial, red, tender, indurated areas occur just beneath the skin, often corresponding to the distribution of the superficial veins. The distinction, usually re­quiring laboratory evaluation, between deep and superficial thrombophlebitis is critical because the former is prone to embolization whereas the latter is not.

The clinical presentation of iliofemoral throm­bosis is characterized by unilateral leg swelling, and the diagnosis usually can be confirmed by Doppler examination. The main differential di­agnosis of this syndrome is extrinsic venous ob­struction by tumor or adenopathy. Deep venous thrombosis in calf veins is more difficult to di­agnose clinically. Doppler studies and impedance plethysmography may be helpful, but a venogram is usually necessary. Venograms are usually re­liable diagnostically; however, inadequate opa­cification of the deep venous system may occur, and areas of previous thrombophlebitis may be difficult to distinguish from new thrombophle­bitis. Phlebitis may occur as a complication of venography in a small number of patients.

Management of deep venous thombosis in­cludes heat, elevation of the extremity, and ad­ministration of anti-inflammatory agents. Anti­coagulation is required to prevent additional thrombus formation and pulmonary embolism. Heparin should be used for immediate anticoa­gulation to keep the activated partial thrombo­plastin time 2 to 2.5 times normal. Heparin is con­tinued for seven to ten days. Warfarin should be given for several days before heparin is discon­tinued, and its effect may be estimated using the prothrombin time. Bed rest is necessary for sev­eral days until pain and swelling have improved. Upon ambulation, an elastic support stocking should be worn. The duration of anticoagulation therapy is controversial but is usually between six weeks and six months. If risk factors for throm­bophlebitis cannot be corrected or if recurrent thrombophlebitis occurs, chronic anticoagulation may be necessary. In patients with deep vein thrombosis who have contraindications to anti­coagulation or in whom pulmonary embolism re­curs despite anticoagulation, surgical plication of the inferior vena cava pr insertion of an inferior vena caval umbrella is indicated to prevent pul­monary embolism. Fibrinolytic agents such as urokinase or streptokinase may be useful to treat deep venous thrombosis but should be used only in patients with serious iliofemoral thrombophle­bitis Superficial thrombophlebitis caused by intra­venous indwelling catheters is treated by removal of the catheter and warm heat. Because of this po­tential complication, IV’s should not be inserted in the leg. If infection is present, appropriate an­tibiotics should be given. Anticoagulation is not used unless lower extremity deep venous involve­ment is present. Heat and elevation should be ap­plied. Ambulation with elastic stockings is pos­sible. Anti-inflammatory drugs may aid in alleviating the symptoms.

Varicose veins (distended, tortuous superficial veins with incompetent valves) can result from thrombophlebitis but may also occur congenitally or in conditions associated with increased venous pressure such as pregnancy, prolonged standing, and ascites. In most people the edema resolves overnight. Many people cpmplain of aching dis­comfort from the superficial varicosities, relieved by elastic stockings and leg elevation. Occasion­ally stripping or sclerosing of the saphenous veins may be necessary. Chronic deep venous insuffi­ciency is more serious and gives rise to more edema, darkening and induration of the skin and sometimes indolent skin ulcers (stasis dermatitis). Arterial pulses are normal. The post-phlebitic syndrome refers to chronic swelling and skin changes in extremities due to chronic venous in­sufficiency, often caused by a previous episode of thrombophlebitis.

Swelling of an extremity can also occur from obstruction of the lymphatic outflow (lymphed­ema). Lymphedema may be idiopathic (primary) or more commonly secondary (for example, due to lymphangitis, neoplasms, adenopathy, or sur­gical removal of lymph nodes). Venous disten­tion, stasis dermatitis, and ulcers are usually not present, but lymphangiography and/or venog­raphy may be necessary to differentiate lymphed­ema from venous obstruction.