Superior Vena Cava Syndrome..What you should know

The superior vena cava (SVC) is easily compressed by tumors arising from the lung, mediastinal structures, or lymph nodes.

Malignancies are the most common cause for superior vena cava syndrome (SVCS).  The leading cause of malignancy associated with SVCS is lung cancer, accounting for as many as 60% to 85% of all cases

But, as more and more indwelling central venous access devices are used, intrinsic thrombus is becoming a significant cause for SVCS,accounting for as many as 20% to 40% of all cases.

Clinical picture

SVCS causes edema in the upper body, particularly in the head and neck . This edema may be significant enough to compromise the lumen of the larynx, causing

dyspnea and stridor, and compromise of the pharyngeal lumen, causing dysphagia.

The most concerning symptoms are neurologic, such as headaches, confusion, or even coma, suggesting cerebral ischemia. Brain stem herniation and death can potentially occur.

However, the usual course of SVCS is that collaterals eventually develop, and symptoms tend to improve when this happens.

Management

 
However, its presence is, in itself, a poor prognostic marker.

If a true emergency exists, then a stent can be emergently placed in the SVC if the expertise to do so is available. Stenting is now considered first-line treatment of SVCS from benign causes, and many experts believe this can also be extrapolated to malignant causes.

Otherwise, therapy directed at the underlying cause should be used, and symptoms usually start improving rapidly if the tumor is responsive.

Although not a true emergency unless central nervous system (CNS) symptoms are present, the presence of SVCS at diagnosis does portend a poor prognosis in lung cancer and lymphoma, with overall median survival only 5 months.

SVCS is not considered a true oncologic emergency unless neurologic symptoms are present