Study Hints Stenting Tops Angioplasty Alone for Stubborn DVT

Download this article's Factoid (PDF & PPT for Gold Subscribers)

In patients with deep venous thrombosis (DVT) who have persistent high-grade residual stenosis even after thrombectomy or catheter-delivered thrombolysis, stenting offers more durable protection from recurrent disease than balloon angioplasty alone. Late-breaking results from a small randomized study were presented May 6, 2011, at the Society for Cardiovascular Angiography and Interventions Scientific Sessions in Baltimore, MD.

For the EVISTA-DVT (Endovenous Infra-inguinal Stenting and Angioplasty in Deep Venous Thrombosis) trial, Mohsen Sharifi, MD, of Arizona Cardiovascular Consultants (Mesa, AZ), and colleagues enrolled 141 DVT patients who experienced residual stenosis greater than 70% after an initial round of percutaneous endovenous intervention. Subjects were randomized to further treatment with stenting (n = 71) or balloon angioplasty alone (n = 70), then underwent venous duplex scanning every 6 months, or sooner if symptomatic. Patients in whom DVT recurrence was suspected (6 patients in the stent group and 15 in the control group) underwent repeat venography with intravascular ultrasound.

Over a mean follow-up of 35 months, 4% of stent patients and 10% of balloon angioplasty patients experienced a recurrence of DVT. Most cases in the stent group were asymptomatic, while most in the control group were mildly symptomatic. For stented patients, the causes of DVT were extension and external compression to venosclerosis, not neointimal proliferation. There were no stent fractures, extrusions, or perforations.

A ‘Paradigm Shift’

Dr. Sharifi told TCTMD in a telephone interview that a “paradigm shift” is needed in the approach to treating venous thromboembolic disease, including DVT.

“The interventional community should look at venous thromboembolic disease more seriously and consider an early invasive approach in suitable candidates to try to reduce the [risk of] post-thrombotic syndrome and recurrent . . . disease, and give a better quality of life to such people,” he urged.

Dr. Sharifi noted that stents are still rarely used in the venous circulation. “Not many interventionalists have an interest. It’s dismissed and can be regarded as virgin territory for the cardiologist,” he said, adding that technically the procedures are no more difficult than those performed in the arterial vasculature, but clinicians may require a “learning curve to know what the venographic views tell us.”

EVISTA-DVT focused on a specific population: those with proximal occlusive thrombus involving their iliac or femoropopliteal veins. The patients presented with an acute inflammatory picture, Dr. Sharifi said, meaning that they experienced rapid development of edema, erythema, induration, and pain to the extent that their activity and walking were impaired. Although stents should not be considered a first-line treatment in these cases, the current results indicate that “these areas can be effectively targeted with stents once the clot has been dissolved with thrombolysis,” he concluded.

Stephen Jenkins, MD, of the Ochsner Medical Center-Kenner (Kenner, LA), agreed in a telephone interview with TCTMD that cardiologists have been very reluctant to perform venous stenting. In fact, until recently the US cardiology societies had no specific guideline recommendations for such procedures. But in April 2011, the American Heart Association published a statement, which Dr. Jenkins coauthored, about the management of venous thromboembolism (Jaff MR. Circulation. 2011;123;1788-1830).

Importantly, the document classified angioplasty and stenting of DVT after thrombolysis a class IIb, level of evidence C designation, Dr. Jenkins said. “What’s new is that this trial, if we had had it, would have allowed us to give [stents] a level of evidence B,” meaning that the literature includes 1 randomized trial, albeit small.

The reluctance on the part of cardiologists to stent veins arises from a lack of data and education, he noted, as well as simply being out of their comfort zone. Before stenting, “[y]ou have to keep these patients in the hospital for several days, thrombolysing them to clean them up before you can find out where the narrowing is and what caused it,” Dr. Jenkins said, adding that only then is it apparent where to place the stent.

Asked about the durability of stenting for this indication, Dr. Jenkins clarified that stent use does not affect other aspects of treatment such as medical management and anticoagulation. Serial follow-up also remains key. “What happens, though, a vein is a different bird than an artery. When we stent veins, we have a different long-term outcome. We don’t have as much neointimal hyperplasia, restenosis, fibrosis, etc,” he explained, adding that stents help prevent extrinsic compression, which can be an underlying cause of DVT.

Cost Considerations

In a telephone interview with TCTMD, Ajay J. Kirtane, MD, SM, of Columbia University Medical Center (New York, NY), acknowledged that although DVT is traditionally managed by medical therapy alone, there is an “emerging interest” in percutaneous interventions to prevent patients from experiencing persistent swelling and pain as well as possibly leg ulceration.

“The big thing, though, is if you were to look nationally at how many people were actually getting thrombolysis and interventional therapies for DVT, it’s very few,” he said, stressing that many DVT patients do not, in fact, need invasive treatment.

Recent data on thrombolysis and adjunctive therapies are encouraging, Dr. Kirtane noted, “but everything we do incrementally is going to add cost.”

“Each of these stents is very expensive,” he said, pointing out that the DVT recurrence rate was low in the study. “So, do we want to add that much more cost to a procedure that already is going to be somewhat costly?”

Dr. Jenkins countered that when considering cost, “[w]hat you’re asking is the difference between a plain old balloon for angioplasty vs. a stent. Peripheral stents, because they’re not drug coated, are much cheaper than coronary stents. A balloon is several hundred dollars, and a stent may be $500 or $600 depending on which one you use. So it’s a minimal increase in cost for the stent, and it looks like you’re [significantly] decreasing repeat procedures just by virtue of cutting restenosis in half. It doesn’t take many procedures saved to buy a whole lot of stents. Come in the hospital, get thrombolyzed, stay several days—that’s $50,000.”

For his part, Dr. Sharifi noted that his research in the TORPEDO trial has suggested that prompt use of percutaneous endovenous intervention reduces the likelihood of recurrence and post-thrombotic syndrome, both of which can add cost by requiring repeat trips to the doctor and the hospital. “Now if the stent further contributes to that reduction, and I think it does,” the treatment could be cost effective, he said. “But we need more studies to look at it from an economic perspective.”

Study Details

Percutaneous endovenous intervention modalities included Angiojet (Medrad; Warrendale, PA), Trellis (Bacchus Vascular; Santa Clara, CA), and thrombolytic therapy via infusion catheter.

In the stent group, 45 subjects were treated with the Gore Viabahn Endoprosthesis (WL Gore & Associates; Newark, DE), 24 with the Protege stent (ev3; Plymouth, MN), and 16 with the Absolute stent (Abbott; Abbott Park, IL).

 

---

Source:
Sharifi M. Endovenous infra-inguinal stenting and angioplasty in deep venous thrombosis trial (EVISTA-DVT). Presented at: Society for Cardiovascular Angiography and Interventions Scientific Sessions; Baltimore, MD; May 6, 2011.

 

 

Related Stories:

• Ultrasound Tests Equivalent for Detecting DVT
• Catheter-Based Device Can Bust DVT Clots Safely and Effectively
• Stenting of Obstructions Effective in Treating Deep Venous Reflux