Superior vena cava obstruction

Superior vena cava (SVC) obstruction can occur from extrinsic compression, intrinsic stenosis, or thrombosis. Malignancies are the main cause and are considered an oncologic emergency. Superior vena cava syndrome (SVCS) refers to the clinical syndrome with symptoms that results from this obstruction.

Clinical presentation depends on the speed, severity, and location of superior vena cava obstruction 5. Collateral drainage may develop with slow obstruction and patients may have no or only mild symptoms.

With acute superior vena cava obstruction, symptoms include facial and neck swelling, facial flushing, bilateral upper extremity swelling, neurological signs, dyspnea, headache, and cough.

The Pemberton maneuver 8 might be a useful physical examination tool. The maneuver is achieved by having the patient elevate both arms until they touch the sides of the face. A positive Pemberton's sign is marked by the presence of facial congestion and cyanosis, as well as respiratory distress after approximately one minute.

In long-standing cases with 60% or more stenosis, collateral channels are formed to restore venous return. Various collaterals are formed depending on the site of the obstruction:

  • pre azygos: in this conditions mainly the right superior intercostal veins serves as the collateral pathway to drain into the azygos vein.
  • azygos: when the azygos vein is also obstructed the collateral circulation establishes between SVC and IVC via minor communicating channels i.e. internal mammary veins, superior and inferior epigastric veins to iliac veins, and finally into the IVC.
  • post azygos: in this case, the blood from the SVC is distributed into the azygos and hemiazygos and then into the IVC tributaries i.e. ascending lumbar and lumbar veins.

The most efficient collateral system is right superior intercostal and azygos circulation. For this reason, most of the patients with pre azygos obstruction of SVC remain asymptomatic for a long period of time.

Indirect signs on chest x-ray, such as superior mediastinal widening and right hilar prominence that may indicate the presence of mediastinal mass. 

Is the imaging modality of choice. Enhanced CT shows the location and severity of the SVC obstruction, superimposed thrombosis, a mediastinal mass or lymphadenopathy, collateral vessels, and associated lung masses. 

See: superior vena cava obstruction: grading 

Treatment of SVCS will depend on the cause of the compression. Thrombolysis and anticoagulation may be indicated for thrombosis. In cases of compression, endovascular treatment with self-expandable bare stents is an effective SVCS therapy 6. With carcinoma or infection, specific drugs or radiation may be used 7.  

Article information

rID: 19760
Section: Syndromes
Synonyms or Alternate Spellings:
  • SVC stenosis
  • Superior vena cava stenosis
  • SVC syndrome
  • Superior vena cava compression
  • SVC obstruction
  • Obstruction of the superior vena caval
  • Obstruction of superior vena caval
  • Superior vena caval compression
  • SVC compression
  • Superior vena cava syndrome
  • Superior vena cava syndrome (SVCS)

ADVERTISEMENT: Supporters see fewers/no ads

Cases and figures

  • Case 1: with SVC syndrome
    Drag here to reorder.
  • Case 2
    Drag here to reorder.
  • Case 3
    Drag here to reorder.
  • Case 4: tumor thrombus
    Drag here to reorder.
  • Case 5
    Drag here to reorder.
  • Case 6: treated with stent
    Drag here to reorder.
  • Case 7: with internal mammary vein collaterals
    Drag here to reorder.
  • Case 8
    Drag here to reorder.
  • Case 9: pre azygos obstruction of SVC and resultant right superior intercostal-azygos collaterals.
    Drag here to reorder.
  • Case 10: likely chronic
    Drag here to reorder.
  • Case 11: causing hepatic hot spot sign
    Drag here to reorder.
  • Case 12
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.