It has been suggested that SVCS arises when a thrombus forms in a partially occluded vein. In patients with a documented thrombus in the SVC, treatment may include thrombectomy, with or without tissue plasminogen activator or other thrombolytic agents such as streptokinase or urokinase.
There have been numerous small studies using an intravascular expandable stent to reopen the occluded SVC; however, no prospectively designed comparative studies have been published. The reported response rates have been about 90% or greater.[Level of evidence: II] There is no agreement on the need for anticoagulant therapy after stent placement. In one series that used anticoagulant therapy for patients as part of the treatment protocol, there were reports of reocclusion after this therapy was stopped.[Level of evidence: II] However, in another study, 17 cancer patients who were treated with stents and who did not have anticoagulant therapy had no occlusions.[Level of evidence: II]
Surgical bypass of an obstructed SVC is more appropriate for patients with a benign obstruction than with a malignant obstruction, although surgical bypass has also been used for patients with malignant obstructions.
Patients and family members are often frightened and anxious because of the symptoms produced by SVCS, particularly swelling, dysphagia, coughing, and hoarseness. It is important to provide information to patients and family members on the cause of the symptoms and on short-term measures for palliation, especially during the diagnostic period. When aggressive treatment is declined because of the terminal nature of the underlying disease, it may be necessary to teach symptom management approaches to patients and family members.
Because most adult patients who develop SVCS have lung cancer, the treatment and psychologic support approaches that are developed for SVCS should take into account the patient's prognosis and psychologic condition, goals of care, and other symptoms caused by the malignancy.
As described in other sections of this summary, SVCS refers to the symptoms associated with the compression or obstruction of the SVC; the compression of the trachea is termed superior mediastinal syndrome (SMS). Because SMS and the resulting respiratory compromise frequently occur in children with SVCS, the two syndromes have become almost synonymous in pediatric practice.[26,27] In adults, the trachea and the right mainstem bronchus are relatively rigid structures compared with the vena cava, but in children these structures are more susceptible to compression. In addition, the relatively smaller intraluminal diameters of a child's trachea and bronchus can tolerate little edema before respiratory symptoms occur. Because of this accompanying respiratory component, SVCS in children differs from the adult syndrome and constitutes a serious medical emergency.
The most common symptoms of SVCS in children are similar to those in adults and include coughing, hoarseness, dyspnea, orthopnea, and chest pain. Symptoms that are less common but more serious are anxiety, confusion, lethargy, headache, distorted vision, a sense of fullness in the ears, and, especially, syncope.