Superior vena cava syndrome in critically ill cancer patients

Abstract

Superior vena cava syndrome (SVCS) is the result of any condition that causes obstruction to blood flow. The clinical picture depends on the idiosyncrasies of the patient, location, and time of the obstruction. The diagnosis of SVCS is clinical and is complemented with testing such as computed tomography (CT) and radiography (X-ray) of the thorax. The causes of SVCS range from benign to malignant. However, malignant tumors represent 85-95% of cases with non-small cell lung cancer representing 50% of all malignant causes. SVCS is an oncological emergency; nonetheless, it is an uncommon complication. Each year 15,000 North Americans suffer from this condition, and 10% of patients with left hemithorax malignancies will develop SVCS. In SVCS, a venous obstruction of the superior portion causes increased venous pressure. This leads to a dilation of the superficial collateral veins; facial edema; conjunctival edema, with or without proptosis; and central nervous system (CNS) symptoms. Dyspnea is the most common symptom, followed by chest pain, cough, and stridor, among other signs. Cerebral edema can also be present which produces headache, confusion, and coma. Radiotherapy and chemotherapy continue being first-line treatments with a high success rate. However, the definitive treatment plan depends on the etiology of SVCS. Almost 20 years ago, a recommendation was made to conduct a randomized clinical trial on SVCS comparing particular treatment modalities; such a trial has not yet taken place. Much research is needed, in terms of classification, treatment, and management.