SVC Syndrome

---

Topic: Superior Vena Cava Syndrome
Definition: 

• Any condition leading to obstruction of blood flow through the SVC

Pathophysiology: 

• Pathology in adjacent anatomy (lung, lymph node, thymus, mediastinum) or within the SVC itself obstructs venous return to the right atrium. As the SVC is compressed, venous collaterals form alternative pathways returning blood to the right atrium which can dilate over several weeks. As a result, upper body venous pressure increases, which in extreme cases lead to airway congestion and venous cerebrovascular congestion and edema. Hemomdynamic compromise is most often by direct compression of the heart, not from SVC obstruction. 

Risk factors:

• Indwelling device through the SVC (Central line, dialysis catheter, pacemaker)
• Lung cancer
• Lymphoma
• Thymoma

Presentation:

• Signs – plethoric appearance, dilated neck and chest veins, swollen face/neck/chest
• Symptoms – congestive symptoms (head fullness, swelling), cardiopulmonary symptoms (chest pain, dyspnea, stridor, hoarseness), and neurologic symptoms (headache, confusion, obtundation, visual disturbances)

Work-up​:

• Is the patient unstalbe? Do they have severe SVC?
  • If yes, secure airway, support breathing, support circulation
  • Consult vascular/cardiothoracic surgery
• Patient is stable
  • Confirm diagnosis and evaluate for malignant obstruction
    • CBC, CMP, PT/INR, CXR, CT chest w/contrast
  • Does the patient have a malignant obstruction or thrombosis?
    • Yes -> consult heme/onc and admit
    • No -> observe in ED

References:

1. García Mónaco R, Bertoni H, Pallota G, et al. Use of self-expanding vascular endoprostheses in superior vena cava syndrome. Eur J Cardiothorac Surg 2003; 24:208.
   
2. Rice TW, Rodriguez RM, Light RW. The superior vena cava syndrome: clinical characteristics and evolving etiology. Medicine (Baltimore) 2006; 85:37.
   
3. Schraufnagel DE, Hill R, Leech JA, Pare JA. Superior vena caval obstruction. Is it a medical emergency? Am J Med 1981; 70:1169.
   
4. Wilson LD, Detterbeck FC, Yahalom J. Clinical practice. Superior vena cava syndrome with malignant causes. N Engl J Med 2007; 356:1862.