Superior Vena Cava Syndrome

Malignancy is the most common cause of the superior vena cava (SVC) syndrome. With the increasing use of intravascular devices, the incidence of the SVC syndrome arising from benign etiologies is increasing. We reviewed the etiology and outcome of 78 patients with SVC syndrome over 5 years. Malignancy was the etiology in 60% of the cases, and bronchogenic carcinoma was the most common malignancy. Small cell and non-small cell lung cancer accounted for 17 (22%) and 19 (24%) cases, respectively, but a higher percentage of patients with small-cell lung cancer developed the syndrome (6% vs 1%). Lymphoma and germ cell tumors were other significant malignant causes (8% and 3% of cases, respectively). An intravascular device was the most common etiology in benign cases (22 of 31 cases; 71%), with fibrosing mediastinitis the second most common benign etiology (6 cases). The most frequent signs and symptoms were face or neck swelling (82%), upper extremity swelling (68%), dyspnea (66%), cough (50%), and dilated chest vein collaterals (38%). Dyspnea at rest, cough, and chest pain were more frequent in the patients with malignancy. Procedures performed for diagnostic or treatment purposes did not increase morbidity or mortality.

The superior vena cava (SVC) is the largest central systemic vein in the mediastinum. Imaging (ie, radiography, computed tomography [CT], magnetic resonance [MR] venography, and conventional venography) plays an important role in identifying congenital variants and pathologic conditions that affect the SVC. Knowledge of the basic embryology and anatomy of the SVC and techniques for CT, MR imaging, and conventional venography are pivotal to accurate diagnosis and clinical decision making. Congenital anomalies such as persistent left SVC, partial anomalous pulmonary venous return, and aneurysm are asymptomatic and may be discovered incidentally in patients undergoing imaging evaluation for associated cardiac abnormalities or other indications. Familiarity with congenital abnormalities is important to avoid image misinterpretation. Acquired abnormalities such as intrinsic and extrinsic strictures, fibrin sheath, thrombus, primary neoplasms, and trauma can produce mild narrowing to complete occlusion, the latter leading to SVC syndrome. Each imaging modality plays a role in evaluation of the SVC, helping to determine the site, extent, and cause of pathologic conditions and guide appropriate management. Commonly performed interventional procedures for fibrin sheath and benign and malignant strictures include low-dose thrombolytic infusion, fibrin sheath disruption, venous angioplasty, and stent placement.