Report from ISET: Fast ultrasound-targeted thrombolysis brings down bleeding risk

A new endovascular sonic lysis system reduces thrombolytic dosage for treating peripheral thrombi while lessening the risk of hemorrhage by dissolving clots in as little as 12 hours, according to a report from southern Florida interventionalists at the 2009 International Symposium on Endovascular Therapy held last week in Hollywood, FL.

Catheter-directed thrombolysis remains the standard of care for the treatment of thrombi that cause deep vein thrombosis or peripheral arterial occlusive disease, conditions that may lead to limb amputation, pulmonary embolism, or death. The procedure is time-consuming and costly, however, and may be marred by severe hemorrhages.

Several new techniques that combine conventional thrombolysis with mechanical thrombectomy or ultrasound-enhanced delivery devices have proven effective and so fast that treatment times have been cut from three days to about one day. A new commercially available system could do the job in a fraction of even that time, according to Dr. Constantino Peña, an interventional radiologist at the Baptist Cardiac & Vascular Institute in Miami.

"(The device) is one of several techniques that allow us to treat patients faster and more safely," Peña said in an interview with Diagnostic Imaging. "It would hopefully give patients better outcomes and diminish the risk of complications from these procedures."

Peña showed how the procedure works during a live televised case demonstration at ISET. A 74-year-old patient with a blocked leg artery underwent ultrasound-enhanced catheter thrombolysis with a tenecteplase(Drug information on tenecteplase)/heparin infusion. The procedure required only half the thrombolytic dose and ended with a completely dissolved blood clot 12 hours later. BCVI specialists have performed the procedure on more than 100 patients over the last four years using this technique, Peña said.

Interventional radiologists know that treatment time and thrombolytic dose factor into the bleeding risk and that some patients face a higher likelihood of hemorrhage when treatment goes beyond 24 hours, Peña said. Bleeding complications lessen if physicians apply lower doses in a shorter period of time, precisely what the ultrasound device helps to accomplish.

During conventional catheter thrombolysis, physicians infuse the drug in the clogged area and wait for results. The endovascular ultrasound system combines the catheter with a soundwave-emitting ultrasound wire that helps the lytic infusion macerate and break the clot faster. BCVI physicians are planning to incorporate soon another, even faster computer-controlled endovascular ultrasound-enhanced thrombolysis device.

"It's supposed to increase the speed of lysis up to four times," Peña said.

For more information from the Diagnostic Imaging archives:

Mechanically assisted thrombolysis boosts thrombosis therapy

Intravascular 'sonic lysis' busts peripheral thrombi

Minimally invasive therapies break through in DVT

Ultrasound shows promise for treatment of thrombosis