TUESDAY, Dec. 13 (HealthDay News) -- A procedure in which doctors use a catheter to help reduce complications after deep vein thrombosis (DVT) appears beneficial, a new Norwegian study finds.

DVT involves a blood clot in the legs that can travel to the lungs and become even more dangerous. Nearly half of patients with a DVT can also develop a cluster of complications called post-thrombotic syndrome, characterized by pain, swelling, a sensation of heaviness and skin deterioration.

The new study included 189 patients with DVT who received either conventional blood-thinning treatment alone or conventional treatment plus additional catheter-directed thrombolysis (CDT) using the powerful clot-busting drug alteplase.

In CDT, X-ray imaging is used to help guide a special medication or medical device to the site of the blood clot in order to dissolve it, according to the American College of Radiology and the Radiological Society of North America.

After two years of follow-up, complications linked to DVT had occurred in 41 percent of the patients who received additional CDT and in 56 percent of those who received conventional treatment alone, say a team led by Dr. Per Morten Sandset of the department of hematology at Oslo University Hospital.

That means that adding CDT to treatment reduces the rate of complications by about a quarter. For every seven patients treated with additional CDT, one case of these post-clot complications was prevented, the researchers said.

There were 20 bleeding complications associated with the treatment, however, including three major and five clinically relevant bleeds.

The study appears online Dec. 13 in The Lancet and was to be presented the same day at the annual meeting of the American Society of Hematology in San Diego.

The addition of CDT lowered the complication rate for people with DVT compared to blood-thinners alone, "but was associated with a small additional risk of bleeding," the researchers wrote. But compared with standard therapy, "this bleeding risk seems acceptable," they added.

One expert agreed that the finding could prove valuable.

"This study adds to the evidence base that catheter-directed thrombolysis [clot-busting] should be routinely offered as a safe and effective treatment for patients" with DVT in the legs, said Dr. Robert Lookstein, director of cardiovascular imaging at Mount Sinai Medical Center, in New York City.

More information

The U.S. National Heart, Lung, and Blood Institute has more about deep vein thrombosis.