Superior vena cava (SVC) syndrome results from obstruction of flow through the vessel either by external compression or thrombosis. External compression by intrathoracic neoplasms is the most common etiology, especially lung cancer and lymphoma. Thrombosis is becoming increasingly common due to the use of indwelling catheters and implantable central venous access devices. Most patients are unresponsive to anticoagulation alone which appears to be effective only in the mildest cases. However, recent advances in catheter-based interventions have led to the development of a variety of minimally invasive endovascular strategies to remove venous thrombus and accepted as an important first-line treatment given its high overall success rate and low morbidity as compared with medical and surgical treatments. Ultrasound accelerated catheter-directed thrombolysis (UACDT) has been developed to rapidly and completely resolve the existing thrombus. This technique integrates high frequency, low intensity ultrasound (US) with standard CDT in order to accelerate clot dissolution, reducing treatment time and the incidence of thrombolysis-related complications. An US wave enhances drug permeation through thrombus by disaggregating the fibrin matrix, exposing additional plasminogen receptor sites to the thrombolytic agent. The US energy affects thrombus in the entire venous segment, increasing the probability of complete thrombus clearing. We report the case of a 56-year-old man who presented with a 5 days history of SVC syndrome symptoms who had been receiving chemotherapy for colon cancer through a right subclavian vein port catheter. The patient successfully treated with UACDT with EkoSonic (R) Mach4e Endovascular device with an overnight infusion. (c) 2013 Wiley Periodicals, Inc.