Introduction

Superior vena cava syndrome is a rare disorder caused by partial or complete obstruction of the superior vena cava. The most frequent causes are (1) superior mediastinal tumors (responsible for over 80% of cases), such as adenocarcinoma of the lung, lymphoma, thyroid carcinoma, thymoma, teratoma, synovial cell carcinoma, or angiosarcoma; (2) chronic fibrotic mediastinitis, either idiopathic or secondary to tuberculosis, histoplasmosis, pyogenic infections, or drugs (such as methysergide); (3) thrombophlebitis secondary to indwelling central venous catheters or pacemaker wires; (4) aneurysm of the aortic arch; and (5) constrictive pericarditis.

Clinical Findings

A. Symptoms and Signs
Symptoms include swelling of the neck and face, headache, dizziness, visual disturbances, stupor, and syncope related to progressive obstruction of the venous drainage of the head, neck, and upper extremities. Bending over or lying down accentuates the symptoms; sitting quietly is generally preferred.

The severity of symptoms is dependent on the degree and duration of stenosis and the development of venous collateral circulation. Dilated anterior chest wall veins and facial flushing ultimately can progress to brawny edema and cyanosis of the face and arms. Cerebral and laryngeal edema result in impaired mental status and respiratory insufficiency.

B. Diagnosis
Diagnosis is usually suggested by the history and physical examination. Duplex ultrasound can be suggestive, but more specific anatomic information is obtained with CT scan or MRA, which can also disclose etiologic causes. Contrast venography is reserved for cases in which surgical or endoscopic treatment is anticipated.

Treatment
Therapy is dictated by the cause of the disease and the severity of symptoms. Benign thrombosis is treated with central venous catheter removal, head elevation, and short-course warfarin anticoagulation or thrombolysis and venous angioplasty. Venous bypass (left atrial appendage to internal jugular or innominate vein) has good patency rates in selected patients refractory to more conservative measures. Surgical excision of the fibrous tissue encasing the great vessels may reestablish flow in patients with mediastinal fibrosis or pericardial constriction. Unless concomitant tumor resection is planned, superior vena cava syndrome secondary to malignant disease is preferentially treated by endovascular stenting. Chemotherapy or external beam radiation may also achieve symptomatic improvement in patients with malignancy.

Kalra M et al: Open surgical and endovascular treatment of superior vena cava syndrome caused by nonmalignant disease. J Vasc Surg 2003;38:215.