Superior Vena Cava Syndrome

Superior Vena Cava Syndrome

Anand Swaminathan and Tarlan Hedayati

• Superior vena cava (SVC) syndrome is an obstruction of the superior vena cava leading to decreased drainage of blood from the upper extremities, head, and neck.
• Causes:
  • Intraluminal pathology such as thrombosis or a tumor-invading vessel.
    • Thrombosis can uncommonly be related to an implantable device like a pacemaker/AICD or dialysis catheter.
  • Extraluminal pathology such as compression of SVC from a mass.
    • Most common: Lung cancer, lymphoma.
• History:
  • This is a challenging diagnosis to make due to vague symptoms that are typically subacute in nature.
  • SVC syndrome is a constellation of signs and symptoms and is diagnosed on history and physical examination, most often with a combination of dyspnea and evidence of upper body venous engorgement and edema to the organs of the upper body.
  • Symptoms are often vague.
    • Dyspnea (shortness of breath) is the most common symptom.
      • Patients will often have clear lungs with dyspnea.
      • Bendopnea: dyspnea when bending forward.
    • Facial swelling (edema)
      • This is a common complaint but may be absent on presentation.
      • Can often be related to position (eg., lying flat) and can be evoked by having a patient lie flat.
    • Nasal congestion, cough, or watery eyes
    • Tongue swelling
    • Prominent neck or chest veins
    • Upper extremity swelling
    • Neurologic symptoms
      • Dizziness (particularly with bending forward), headaches, blurred vision, or altered mental status (less common).
• Physical exam:
  • Physical exam features are often absent on presentation.
  • Distended neck or chest veins.
  • Pemberton’s sign: Elevate both of the patient's arms. 
    • A positive sign is development of intense facial plethora and cyanosis in less than 1 minute. 
  • Patients rarely present with hemodynamic compromise or respiratory distress.
  • This syndrome typically develops subacutely thus patients have developed collateral drainage to mitigate symptoms.
  • An acute SVC obstruction without collateral drainage is possible but less common.
• Diagnostics
  • Chest x-ray
    • Approximately 80% of SVC syndrome cases will have abnormalities.
    • Nonspecific findings are common including: widened mediastinum, abnormal contour of mediastinum.
  • CT chest with IV contrast
    • Prefered study for diagnosis.
    • Can identify location and type of malignancy.
    • Can identify thrombus or filling defects.
  • Ultrasound
    • Helpful in ruling out VTE in upper extremity or vessels leading to superior vena cava.
• Management
  • Immediate threats (airway, hemodynamic compromise) are uncommon but can be present in patients with acute, rapid onset of obstruction.
  • Endovascular stenting is the current mainstay of treatment with a high success rate (85-100%).
    • Who does this will depend on the institution: interventional cardiology, interventional radiology or minimally invasive cardiothoracic surgery.
  • Anticoagulation is the mainstay treatment in those with thrombosis causing obstruction.
    • If the patient is unstable, interventional treatment may be indicated with catheter-directed thrombolysis or thrombus aspiration.
  • Steroids may be an option if the patient has a steroid-responsive malignancy (eg., lymphoma or thymoma).