Study at SIR Shows Endovascular Treatment of Chronic DVT May Ease Postthrombotic Syndrome

March 26, 2012—Data presented at the Society of Interventional Radiology's (SIR) annual scientific meeting in San Francisco demonstrated that endovascular treatment of chronic deep vein thrombosis (DVT) reduced disabling symptoms and improved the quality of life for patients experiencing postthrombotic syndrome. The study was led by Mark J. Garcia, MD, who also serves as Chair of SIR's Venous Service Line.

“The important message from our study is there is hope for those patients suffering from postthrombotic syndrome who have been told there are no treatment options available,” commented Dr. Garcia in a press release. “Although great strides have been made in the treatment of acute clots, there have been no real improvements in treatment strategies for chronic clot and postthrombotic syndrome. Medical management with blood thinners and elastic compression stockings are both aimed at the prevention of symptom progression rather than resolution.”

Dr. Garcia noted that the investigators found encouraging technical and clinical outcomes when patients were aggressively treated for chronic DVT that caused postthrombotic syndrome. “Contrary to popular belief, anticoagulants do not actively dissolve the clot; they just prevent new clots from forming,” he stated. “If people are treated with blood thinners alone, the clot remains in the leg. While the body can dissolve a clot over time, the vein often becomes permanently damaged during that time.”

He continued, “While postthrombotic syndrome used to be considered an unusual, long-term after-effect of DVT, it actually occurs frequently and can occur within 2 years of developing DVT. There is increasing evidence that early and complete removal of the blood clot is likely to give people their best chance to avoid disabling symptoms, such as pain, swelling, skin changes, and ulcer formation.”

Over a 3-year period, the investigators performed minimally invasive treatments to restore blood flow in more than 100 patients with from lifestyle-limiting postthrombotic syndrome from chronic DVT. The investigators evaluated their ability to pass through the blocked area and restore blood flow using a combination of treatments, including angioplasty and stenting.

“We asked each person to grade his or her quality of life before and after the procedure, and we evaluated whether the veins remained opened, using ultrasound to look for continued flow or clot recurrence,” said Dr. Garcia.

The investigators reported that successful navigation through the blocked vein occurred in 120 of 122 limbs (98%), with blood flow restored to 118 of 122 limbs (97%). At follow-up, 93% of the patients in the study reported significant symptomatic improvement and 7% were unchanged; none were worse.

Allowing for the loss of some individuals to follow-up, ultrasound exams demonstrated patency in 95% (95 of 100 limbs) at 1 month, 92% (71 of 77 limbs) at 3 months, 88% (57 of 65 limbs) at 6 months, 79% (30 of 38 limbs) at 12 months, and 58% (11 of 19 limbs) at 2 years. No major adverse events were noted.

“This study is important because it demonstrates the ability to potentially change the way individuals with chronic DVT and postthrombotic syndrome are being treated, offering them hope for a significantly improved quality of life,” concluded Dr. Garcia. “We identified a patient need and, as experts in minimally invasive techniques originally devised by our specialty, we were able to fulfill that need. We believe that being able to restore blood flow in veins previously blocked is imperative to ensuring any possibility of long-term success.”

SIR also highlighted the role of interventional radiologists in the ATTRACT (Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis) study, which will be the first United States multicenter randomized trial of a catheter-based treatment for DVT. ATTRACT will determine if the delivery of clot-dissolving drugs into a blood clot using specialized catheter-based treatment prevents postthrombotic syndrome in people with DVT.

The study is led by SIR Fellow Suresh Vedantham, MD, who serves as a Principal Investigator, as well as Principal Investigator Clive Kearon, MB, PhD, and Study Chair Samuel Z. Goldhaber. SIR stated that ATTRACT is the result of an SIR Foundation-sponsored Research Consensus Panel and is sponsored in part by the National Institutes of Health, and endorsed by the Office of the US Surgeon General.

“The ATTRACT trial could fundamentally shift the 50-year-old DVT treatment paradigm to one that includes interventional clot removal as an essential element of standard DVT care,” commented Dr. Vedantham.