Superior vena cava syndrome arising from subclavian vein port catheter implantation and paraneoplastic syndrome.

Central venous thrombosis is an important complication of venous catheterization. We presented a 49-year-old male patient who developed massive central venous thrombosis causing superior vena cava (SVC) syndrome after placement of a right subclavian vein port catheter. The patient had inoperable gastric cancer for which he had been receiving chemotherapy for two years. He had a six-month history of fixed port catheter placement into the right subclavian vein. Contrast-enhanced computed tomography (CT) of the chest showed complete obstruction of the SVC and CT angiography showed extensive thrombosis from the subclavian vein to the end of the SVC. Extensive lung and mediastinal metastases were also observed. Surgical intervention was not considered. Fibrinolytic therapy was instituted with 75 mg tissue plasminogen activator (tPA) infusion for 18 hours. The patient's symptoms and the signs of SVC syndrome disappeared and clinical parameters returned to normal within several hours. The day after completion of fibrinolytic therapy, repeat contrast CT angiography showed total resolution of SVC thrombosis. Slow infusion of tPA may be effective in the treatment of SVC syndrome caused by acute thrombosis.