Data Shows Clot Quickly Removed, Blood Flow Restored In Large Patient Registry
Registry data for more than 500 patients presented today at the Society of Interventional Radiology's 33rd Annual Scientific Meeting show deep vein thrombosis (DVT) treatment with the Trellis device breaks up a blood clot in most patients much quicker than using a drug alone. Using imaging, the device is guided directly to the clot via a catheter in the vein. DVT occurs when the blood clot either partially or completely blocks the flow of blood in the vein. The Trellis device removes the blood clot and restores blood flow much quicker than the current catheter-directed thrombolysis (CDT) technique, which uses a drug alone and can take as long as two to three days to be effective with the patient in an intensive care unit.
"It gets the clot out right away, restoring blood flow in the vein while the patient's blood becomes sufficiently thinned by anticoagulation medication to prevent blood clots in the future. Patients experience dramatic relief of pain, swelling and skin discoloration in just a few hours," says Gerard J. O'Sullivan, M.D., interventional radiologist. Presently, this is the largest commercial data registry by a manufacturer to assess the effectiveness and safety of this type of treatment for DVT.
"This is a very significant advance in DVT treatment, which hasn't changed in more than 40 years," added O'Sullivan. "The procedure is now so commonplace where I work that the ER, oncology and general medicine doctors all refer patients directly to me for this procedure because it works so well and is so safe. With the aid of the Trellis device, this interventional radiology procedure could really change the way DVT patients are treated and should become a standard of care," he said.
The Trellis device combines the use of clot-busting drugs with a drug dispersion device to break up the clot, providing interventional radiologists with physical assistance to break up the clot faster. Because the device disperses the drug throughout the clot, it allows the clot-dissolving drug to work much more quickly -- and often less drug is used, which may lead to a decrease in the risk of bleeding.
Currently, most patients are put on anticoagulation medication (blood thinners), which prevents future clots but does not break up the existing clot.
DVT can lead to serious consequences, including pulmonary embolism (PE) or post-thrombotic syndrome (PTS). Approximately 200,000 individuals die annually as a result of pulmonary embolism. The standard initial treatment with blood thinners is important to prevent a life-threatening pulmonary embolism, but does not treat the existing clot.
Removing these clots is important because about 50 percent of the time, untreated clots will cause PTS, a condition characterized by chronic leg pain, swelling and ulcers. The clot may eventually dissolve on its own, but in the meantime the veins are permanently damaged. PTS is caused by a combination of vein valve damage and blocked blood flow in the vein from residual thrombus (clot).
"My Trellis patients not only felt better right away, but they continued to feel good months later. With anticoagulation alone, it may take days to months for patients to feel better, and some never feel better," said O'Sullivan. Some larger clots do not break up on their own. This leaves the patient with an underlying obstruction or lesion that should be corrected to prevent a future clot. PTS -- while not life threatening -- limits a person's ability to walk or stand for a period of time and can be disabling.
There is growing awareness in the medical community about the need to aggressively treat DVT. Increased focus and awareness of DVT is being brought by new initiatives and standards from a variety of organizations including the Office of the U.S. Surgeon General, the Joint Commission and the American College of Chest Physicians.
"All acute DVT patients should be sent to the interventional radiology department for a consult. We can help their physicians determine the best course of action. If the vein is completely or severely blocked, immediate treatment is needed. Not all partial clots will require treatment, but if the area is still swollen after five to seven days, patients should ask for an appointment with an interventional physician at the hospital," said O'Sullivan. Interventional radiologists are widely available across the United States in most hospital radiology departments.