Isolated thrombolysis is an effective and safe therapy for DVT, research presented at the Society of Interventional Radiology's 33rd Annual Scientific Meeting suggests.

Researchers looked at registry data from 532 patients presenting with upper and lower extremity DVT, between February 2005 and August 2007 at US and international sites.

The thrombus was located in the iliac vein in almost 70 per cent, the femoropopliteal vein in almost 19 per cent, and the subclavian vein in the remainder.

All patients underwent removal of the thrombotic occlusion with the Trellis-8 Peripheral Infusion System, using tPA as the lytic in 92 per cent of the cases with an average dose of 5.9mg.

The researchers said that combined Grade II and Grade III lysis were achieved in 96.8 per cent of cases with acute onset of symptoms, and 90.9 per cent with chronic onset. Adjunctive measures were warranted in 88 per cent owing to underlying chronic obstruction or culprit lesions.

The researchers concluded: "Isolated thrombolysis combined with adjunctive measures form an effective and safe strategy for comprehensive vascular treatment of lower and upper extremity DVT." But they added that prospective, randomized trials with longer follow-up were necessary.

Presenting the findings Dr Gerard O'Sullivan, an interventional radiologist at University College Hospital in Galway, Ireland, said: "This is a very significant advance in DVT treatment, which hasn't changed in more than 40 years."

He described the procedure as "commonplace" in his center. "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."

He noted that not all partial clots would require treatment, but added: "If the vein is completely or severely blocked, immediate treatment is needed."