Vessel

Superior Vena Cava Obstruction

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Superior Vena Cava Obstruction, Superior Caval Vein Obstruction, Superior Vena Cava Occlusion, Superior Vena Cava Syndrome, SVC Syndrome, Collar of Stokes

  • Pathophysiology
  1. Superior Vena Cava Obstruction to flow
    1. Internal Vascular Invasion
      1. Vena cava thrombosis (uncommon complication of implantable devices, pacers, AICD, Dialysis Catheter)
      2. Tumor infiltration
    2. External Compression (e.g. right lung or Mediastinal Mass)
      1. Most common Mediastinal Masses include Lung Cancer and Lymphoma
      2. Mediastinal Mass gradually compresses superior vena cava, blocking entry into right atrium
      3. Results in retrograde flow and regional edema
  2. Superior Vena Cava Obstruction Compensation
    1. SVC is a thin walled, low pressure large vein 2 cm in width and 4-6 cm in diameter
    2. Upper body venous engorgement distributes the fluid
    3. High venous pressures within SVC may be compensated with collateral circulation over 1-2 weeks
      1. Example: Azygous vein may provide some collateral drainage
  • Causes
  1. Malignancy (60% of all cases)
    1. Bronchogenic Carcinoma (80% of malignancy causes)
    2. Malignant Lymphoma (15% of malignancy causes)
    3. Metastatic Disease (to lung, mediastinum or Lymph Nodes)
      1. Breast adenocarcinoma
      2. Testicular seminoma
  2. Vena Cava thrombosis (majority of non-malignant cases)
    1. Long-term venous catheters (40% of thrombosis cases)
    2. Idiopathic
    3. Behcet's Syndrome
    4. Polycythemia Vera
    5. Paroxysmal Nocturnal Hemoglobinuria
    6. Long-term shunts
    7. Long-term Pacemakers
  3. Other Benign Disease (Rare)
    1. Mediastinal fibrosis
      1. Post-Radiation Therapy
      2. Idiopathic
      3. Histoplasmosis
      4. Actinomycosis
      5. Tuberculosis
    2. Benign Mediastinal tumor
      1. Aortic aneurysm
      2. Dermoid tumor
      3. Goiter
      4. Sarcoidosis
  • Symptoms
  1. Presentations are typically subacute and progressive
  2. Dyspnea (50%)
    1. Worse with bending forward
  3. Neck and facial swelling (40-82%)
    1. Head fullness or pressure Sensation
    2. Provoked by lying supine
  4. Swelling of trunk and upper extremities (40%)
  5. Local Airway Compression
    1. Cough
    2. Dysphagia
    3. Choking Sensation
    4. Hoarseness
    5. Lacrimation
    6. Nasal Congestion
  6. Headache
    1. Common presenting complaint
    2. Secondary to Increased Intracranial Pressure
  7. Referred Pain
    1. Chest Pain
    2. Shoulder Pain
  8. Neurologic
    1. Dizziness (provoked by bending forward)
    2. Visual changes or Blurred Vision
    3. Headaches
    4. Syncope
    5. Altered Mental Status
  • Signs
  1. Thoracic chest vein distention (65%)
  2. Neck vein distention (55%)
  3. Facial Edema (55%)
  4. Tachypnea (40%)
  5. Plethora of the face and Cyanosis (15%)
  6. Edema of upper extremities (10%)
  7. Paralysis of Vocal Cords (3%)
  8. Horner's Syndrome (3%)
  9. Distended antecubital veins
  10. Tongue Swelling
  11. Pemberton's Sign
    1. Patient elevates both arms and observe face for one minute
    2. Positive if significant facial swelling (plethora) and Cyanosis within the first minute
  12. Clear lungs despite Dyspnea and Tachypnea
    1. See Causes of Dyspnea with Clear Lung Sounds
  • Associated Conditions
  • Imaging
  1. Chest XRay
    1. Mass identified in 90%
    2. Right superior mediastinum widening (75%)
    3. Hilar Adenopathy (50%)
    4. Right Pleural Effusion (25%)
  2. Chest CT with IV Contrast (preferred)
    1. Identifies mass lesions and sites of SVC obstruction and thrombosis
    2. Collateral vessel development is a sensitive and specific marker of SVC Syndrome
      1. Test Specificity: 96%
      2. Test Sensitivity: 92%
  3. Ultrasound
    1. Consider in the evaluation for upper extremity Deep Vein Thrombosis
  4. Other Imaging modalities
    1. MR Venogram
    2. Cavogram
  • Management
  1. Severity of airway and vascular compromise varies by timing of progression
    1. Rapid progression may not allow for compensation, resulting in acute airway compromise (uncommon)
  2. Supportive care for airway compromise
    1. ABC Management
    2. High-Dose Corticosteroids
      1. Most effective in steroid-responsive malignancy such as Lymphoma or thymoma
    3. Elevate the head of the bed
    4. Avoid Diuretics
  3. Identify mass etiology
  4. Reduction in mass size
    1. Emergent Intervention RadiologyConsultation
    2. Other modalities
      1. Radiation Therapy (e.g. Non-Small Cell Lung Cancer)
      2. Chemotherapy
      3. Surgical decompression
  5. Consult Oncology and Cardiothoracic Surgery acutely
    1. Palliative CareConsultation once stabilized
  6. Anticoagulation with Heparin
    1. Indicated for venous thrombosis
    2. Consult for catheter directed Thrombolysis or thrombectomy in hemodynamically unstable patients
  7. Endovascular stenting
    1. Common acute management with 85 to 100% success rate
    2. Improvement is seen within days
    3. Effective even when tumor mass is not reducible
  • Prognosis
  1. Poor prognostic sign
    1. Predicts 90% mortality in 3 years
    2. Median survival: 6 months
  • References
  1. Long, Long and Koyfman (2020) Crit Dec Emerg Med 34(11): 17-24
  2. Swaminathan and Hedayati (2022) EM:Rap 22(6): 7-9
  3. Higdon (2018) Am Fam Physician 97(11):741-8 [PubMed]