New treatment effective for deep vein thrombosis
A new treatment that injects, or laces, blood clots with a fiber-binding thrombolytic agent effectively treats deep vein thrombosis (DVT) and reduces the risk of subsequent recurrence or bleeding, according to a pilot study published in the February issue of Radiology.

“This treatment regimen is able to clear blood clots rapidly and safely, restoring blood flow in the veins of the lower leg, and the results are durable,” said lead author Richard Chang, MD, chief of interventional radiology, department of radiology at the National Institutes of Health (NIH) in Bethesda, Md.

Most patients with DVT are treated solely with anticoagulation therapy (blood thinners) and compression stockings, which can lead to post-thrombotic syndrome.

Treatments with thrombolytic therapy could potentially protect against the occurrences, but can pose a bleeding risk. Therefore, Chang and colleagues worked to develop a new thrombolytic treatment regimen for DVT.

The researchers examined 20 patients with acute DVT, who were treated with direct intraclot lacing of the thrombus with a clot-dissolving agent, called alteplase, and full systemic anticoagulation. With the treatment, after lacing one vein segment with alteplase, the interventional radiologist can immediately direct catheters to treat other vein segments to ensure that the entire clot has been adequately treated, the study reported.

The results of the study showed that blood flow was restored throughout the deep venous system in 16 (80 percent) of the 20 patients during therapy with complete resolution of symptoms in 18 patients (90 percent) after six months of anticoagulation, according to the researchers. The study found that alteplase was cleared from the patients' circulatory system within two hours of treatment, reducing the risk of subsequent bleeding.

The authors said that there were no serious complications or bleeding during the treatment, and no cases of post-thrombotic syndrome or recurrent clotting during follow-up of 3.4 years.

"With this therapy, pain and swelling resolve rapidly, and, in most cases, the patient is able to resume all normal activity within a week," said the study's co-author, McDonald K. Horne III, MD, hematology, department of lab medicine at NIH.

The authors suggested that larger clinical trials are required to further support the efficacy of the treatment.