Superior Vena Cava (SVC) Syndrome

Superior vena cava (SVC) syndrome is caused by the severe obstruction or occlusion of the SVC and can result in significant morbidity and mortality
Malignancy is the most common cause of SVC obstruction, accounting for approximately 70% of cases
Recently the incidence of device related SVC syndrome from central venous catheters and pacemaker or defibrillator leads has been increasing


The most common presenting symptoms include facial and neck edema, distended neck and chest veins, watering eyes, and dizziness particularly when leaning forward
Some patients with malignant SVC syndrome may present with life-threatening symptoms of cerebral, laryngeal, and pharyngeal edema due to sudden elevation in venous pressures from rapidly occluding SVC


In SVC obstruction, the flow of blood is diverted to the right atrium through a collateral venous network, which can take several weeks to accommodate the usual blood flow of the SVC
The severity of presentation of SVC syndrome is inversely related to the development of these collateral veins and the rapidity with which SVC obstruction develops
The diagnosis of SVC syndrome is based on the clinical presentation and advanced imaging Contrast-enhanced CT scanning provides optimal visualization of the SVC and can localize the extent of venous blockage, differentiate thrombosis from extrinsic compression, and identify collateral pathways


The management of SVC syndrome is evolving
In the past, radiation therapy (RT) was considered first line treatment, particularly in patients with airway obstruction
However, in recent years, endovascular therapy (ET) is more frequently used first, or in combination with RT, to provide rapid relief of clinical symptoms with reduced