Abstract Background Heparin-based anticoagulation is the first-line therapy for pulmonary embolism and deep vein thrombosis. However, when thrombus progresses despite adequate anticoagulation, placement of an inferior vena cava (IVC) filter may be considered. Thrombus extension following IVC filter placement may complicate retrieval and necessitate thrombolytic therapy, which carries a risk of bleeding. Here, we report a case in which catheter-directed thrombolysis (CDT) using monteplase was successfully performed for thrombus progression after IVC filter placement without any hemorrhagic complications. Case Summary A 33-year-old man presented with sudden chest pain and dyspnea. He developed pulseless electrical activity (PEA) shortly after arrival and was resuscitated with veno-arterial extracorporeal membrane oxygenation (ECMO). Pulmonary arteriography and CT revealed bilateral pulmonary artery thrombi. Anticoagulation therapy was initiated, and ECMO was discontinued on day 8 to stabilize his hemodynamics. However, pulmonary embolism recurred and deep vein thrombosis progressed despite adequate heparinization, necessitating placement of an IVC filter and ultimately CDT using monteplase via the pulse-spray method. The thrombus burden resolved without significant bleeding. Discussion If thrombus progression is observed after IVC filter placement, pulse-spray CDT using monteplase may help prevent complications, such as difficulty in filter retrieval and development of post-thrombotic syndrome, without any bleeding, particularly when urokinase is unavailable.
Sato et al. (2026) studied this question.