Superior Vena Cava (SVC) Syndrome

SVC Syndrome

• • 80-90% caused by malignant tumors

  • -Lung cancer (90%)

    -Thymoma

    -Hodgkin disease

    -Lymphosarcoma

    -Metastatic melanoma

    -Breast or thyroid cancer

  • Benign tumors unusual

  • -Substernal goiter

    -Large benign mediastinal masses

    -Atrial myxoma

  • The following thrombotic conditions are unusual causes:

  • -Polycythemia

    -Mediastinal infection

    -Indwelling catheters

  • Trauma may produce acute obstruction

  • Clinical presentation varies with: abruptness of onset, extend of occlusion, collateral pathways

  • Venous pressure in arms/head: 200- 500 mm H2O

  • Severity of symptoms correlates with pressure

  • Cerebral edema can occur with complete obstruction

  • Symptoms milder with patent azygous vein

  • Azygous venous flow can increase to 35% of venous return (normal is 11%)

  • Thrombus can propagate proximally to innominate and axillary veins

Epidemiology

• • 80-90% caused by malignant tumors

  • Lung cancer 90% of malignant tumors

  • Incidence is 3-5% in lung cancer patients

  • Male:female ratio is 5:1

  • Malignant SVC obstruction: 35% have thrombosis of innominate or axillary vein, 15% have complete caval obstruction without thrombosis, 50% have partial SVC obstruction

Symptoms and Signs

• • Nasal congestion often earliest symptom

  • Swelling in face, arms, shoulders

  • Blue/purple discoloration of skin

  • Headache, nausea, dizziness, vomiting, vision changes, drowsiness, stupor

  • Cough, hoarseness, dyspnea (edema of vocal cords)

  • Symptoms may be worse when patient lies on back or bends forward

  • Esophageal varices may develop: GI bleeding

  • Neck, arm veins may be visibly distended

  • Fibrosing mediastinitis: Early morning edema of face and head

  • Unilateral symptoms suggest ipsilateral occlusion

  • Effort thrombosis or axillary vein and innominate vein obstruction from elongation and buckling of innominate artery in unilateral cases

Imaging Findings

• • Chest film: May show right upper lobe lung lesion or right paratracheal mass

  • Venography: Determines location and extent of obstruction

  • Interosseous azygography: Useful to determine patency of azygous vein

  • Aortography or CT scan: Excludes aortic aneurysm

• • Measure upper extremity venous pressure: > 350 mm H2O

  • Location/extent of obstruction determined by venography

Rule Out

• • Angioneurotic edema

  • Congestive heart failure

  • Constrictive pericarditis

• • Physical exam

  • Chest x-ray

  • Chest CT scan

  • Venography

• • Etiology of obstruction determines treatment

Cancer

• • Diuretics, restriction, head elevation prompt radiation or chemotherapy

  • Often subsides at 7-10 days of treatment

  • Fibrinolytics or anticoagulation can be considered but rule out metastatic cerebral metastases with CT/MRI

  • Percutaneous stents allows good immediate drainage; long-term results unknown

  • Tissue diagnosis often needed for therapy (via fine-needle aspiration, bronchoscopy, mediastinoscopy, or thoracotomy)

  • Avoid operation if acutely obstructed due to high bleeding rate

Benign Tumors

• • Surgical excision for incomplete obstruction

  • For complete obstruction: Many ...