Multimodal thrombectomy device holds promise in DVT treatment

A novel thrombectomy device using a sequestered approach delivers positive clinical outcomes in the treatment of high-risk, large-volume deep vein thrombosis (DVT), according to a study.

“Current treatment options for DVT are limited in both effectiveness and safety, in part because the treatment of the DVT cannot be confined to a defined sequestered treatment zone,” the researchers said. “We therefore developed and tested a novel thrombectomy device that enables the sequestration of a DVT to a defined treatment zone during fragmentation and evacuation.”

Lead researcher Usama Ismail of Caeli Vascular, Inc., and his team, in collaboration with Nordson Medical, Inc., developed a thrombectomy device that separated a treatment zone between two balloons. This multimodal sequestered thrombectomy catheter (MMSTC) contained several extruded tubes, with multiple inner lumens.

The device had a proximal catheter made of polyether block amide, coated to make the surfaces water-resistant. This catheter was then inserted over a guide wire, terminating in an inflatable proximal balloon that demarcated and sealed the proximal end of the treatment zone.

A second component of the MMSTC was a thinner but longer distal catheter. This could be inserted over the same guide wire through the lumen of the proximal catheter and terminated in a second distal balloon that “defied” the distal end of the treatment zone.

Notably, the distal catheter contained flush ports, allowing surgeons to infuse drugs such as thrombolytics, as well as introduce fluid to the treatment zone that flushes fragments of thrombus down the lumens of the proximal catheter. In addition, this lumen can deliver simultaneous suction.

Compared to a predicate thrombectomy device, the MMSTC attenuated distal DVT embolization during ex vivo thrombectomy. The sequestered approach also enabled isovolumetric infusion and suction, facilitating clearance of the sequestered zone without substantially affecting the vein wall diameter. [Sci Rep 2022;12:5295]

The ex vivo flow model demonstrated the effectiveness of the adjustable double-balloon design of this device at isolating the thrombus and reducing distal embolization. This finding was consistent with previous studies using similar thrombosis circuits to assess embolus volume, size, and particle counts. [Neuroradiology 2008;50;43-52; CardioVasc Interv Radiol 2021;44:318-324; Stroke 2010;41:647-652]

“The MMSTC prototype demonstrated effective thrombus removal, significant reduction of distal embolization, and a mechanism to decrease vein wall collapse and over-distension during flushing of a defined treatment zone,” the researchers said. “Furthermore, results with the MMSTC suggest incremental benefits over predicate devices that are already in clinical practice such as the Penumbra Indigo CAT 5 Fr suction thrombectomy catheter.”

Earlier studies have reported the risk of distal thrombus embolization, which can result in severe haemodynamic compromise, need for invasive measures, or even death. [Cardiovasc Interv Radiol 2001;24:42-48; Ann Intern Med 2008;149:698-707; Circulation 2011;123:1788-1830]

“DVT is characterized by the formation of blood clots within the deep venous system of the body,” the researchers said. “If a DVT dislodges it can lead to venous thromboembolism and pulmonary embolism, both of which can lead to significant morbidity or death.”