New Clot-Busting DVT Treatments
Pharmacomechanical catheter-directed thrombolysis (PCDT) refers to the injection of a clot-busting drug (such as TPA) directly into the blood clot through a specially-designed, catheter-mounted device that may also break up the clot and/or remove the clot fragments. This combined drug-device approach can significantly reduce the amount of drug that needs to be given (which probably improves safety), the treatment time, the length of stay in the intensive care unit, and hospital costs. Several PCDT methods are available but two have sparked particular interest because they can enable clot removal treatment to be completed in a single 2-hour procedure, which is must faster than previous methods which involved 24-48 hours of drug treatment. In the ATTRACT Trial, most patients will be treated with one of these two methods:

“Powerpulse” refers to a method of using the AngioJet Rheolytic Thrombectomy System (MEDRAD Interventional - Possis, Minneapolis, MN) to treat DVT in a single procedure. The AngioJet uses high velocity saline jets to fracture and remove blood clots. With the Powerpulse method, the AngioJet is first used to deliver and disperse a clot-busting drug directly into the blood clot by a powerful pulse-spray injection. The drug is allowed to sit within the clot for 30 minutes, then the AngioJet is used to remove the softened thrombus fragments.

“Isolated Thrombolysis” refers to use of the Trellis Peripheral Infusion System (Covidien - Bacchus, Santa Clara, CA) to treat DVT in a single procedure. This device delivers a clot-busting drug directly into the clot, then spreads the drug within the clot using an oscillating wire.

The AngioJet and Trellis devices are FDA-approved for the delivery of thrombolytic drugs into the peripheral blood vessels. The AngioJet is also FDA-approved for the removal of clot from the iliac and femoral veins. The clot-busting drugs (e.g. TPA) that are commonly used for PCDT in modern clinical practice are approved for the treatment of heart attacks and strokes, but are used “off-label” by physicians for the treatment of DVT.