The superior vena cava transports blood from the head, neck, upper extremities, and upper chest to the right atrium. Obstruction in this large vessel can result in several symptoms and may constitute a medical emergency. It should be treated immediately if airway obstruction or cerebral edema are present.
SVC syndrome most commonly occurs because of compression due to a mediastinal mass. Malignancies are frequently found (60-70%) but benign tumors have also been reported, too.
Thrombus formation in the superior vena cava can result in blockage of blood flow that can lead to superior vena cava syndrome. This etiology is mostly associated with the usage of indwelling intravascular devices including catheters, pacemakers, and implantable cardioverter-defibrillators (ICDs). Other factors may also contribute to thromboses such as inflammation and hypercoagulability.
The superior vena cava is connected to the left and right brachiocephalic veins which collect blood from the head, neck, and upper extremities. By obstructing the superior vena cava, blood can build up back to the head causing edema of the face (facial plethora) and edema of upper extremities. Jugular venous distention (JVD) can also occur because of the connection between jugular veins and brachiocephalic veins.
A large buildup of blood in the superior vena cava can result in massive engorgement of the veins of the upper extremity, face, and chest. These may show visible dilation and tortuosity in the skin.
Excess collection of blood in the head can increase intracranial pressure (ICP) which can increase the risk of aneurysms and their rupture. This can also lead to venous stroke. This condition is rare, but headache, cerebral edema and papilledema should be considered a medical emergency.
Based on clinical diagnosis, management should begin by elevating the patient's head to reduce the amount of congestion at the top of the body. Further management is to treat the underlying disorder of SVC syndrome. If it is caused by a thrombus due to an indwelling intravascular device, removal should be the choice. Anticoagulation therapy and catheter-directed thrombolysis should be considered during the removal. If it is due to a malignancy, chemotherapy and radiotherapy should be given as indicated. Endovascular stenting is widely considered to be useful.
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