Breakthrough in pulmonary embolism thrombectomy

Mermaid Medical’s Angel Catheter is an innovative vascular interventional device. Its core technology seamlessly integrates an inferior vena cava (IVC) filter with a multi-lumen central venous catheter (CVC), specifically designed for patients in the intensive care unit (ICU) at high risk of pulmonary embolism (PE) and with contraindications to anticoagulation.

Structurally, the device uses a 9F outer diameter, 30cm effective length three-lumen catheter as its main body. A conical, self-expanding Nitinol filter is permanently connected to the distal end of the catheter. The filter is 50mm long with a maximum expanded diameter of 30mm. Its conical structure features a wide proximal opening, allowing blood flow while capturing thrombi at the distal end. The distal end of the filter is designed to float freely, automatically adjusting its expansion according to the diameter of the vena cava to ensure close contact with the vessel wall without damaging the intima. The outer wall of the catheter has 1cm depth markers and a hydrophilic coating within a 24cm range, facilitating insertion and positioning during femoral vein puncture. The three independent chambers are used for drug infusion, blood sampling, and central venous pressure monitoring, respectively. The distal and proximal ports support high-pressure injection of contrast agents and are compatible with standard ICU monitoring equipment.

Technically, this device is based on a mechanical thrombus interception mechanism. Blood flows in from the wide proximal end of the filter, where thrombi are trapped by the filter mesh, while clean blood continues to flow to the lungs. The key lies in the permanent mechanical connection between the filter and the catheter—when PE protection or central venous access is no longer clinically necessary, removing the catheter ensures simultaneous removal of the filter, fulfilling the core promise of “guaranteed retrieval” and solving the long-term complications caused by the easy forgetting of retrieval in traditional IVC filters. The insertion process can be completed at the bedside, with the location confirmed by abdominal X-ray after femoral vein puncture, eliminating the need to transport critically ill patients to the interventional operating room and significantly reducing transport risks.

This device is suitable for short-term use (<30 days). Multiple clinical studies have demonstrated its effectiveness in preventing PE, with a thrombus capture rate of approximately 29.4% within the filter, and no device-related serious adverse events.