BALTIMORE—Endovenous stents in the femoropropliteal veins are safe and effective; however, the natural history of stenting in the venous circulation is different than arterial stents, according to the late-breaking EVISTA-DVT trial presented May 6 at the 2011 Society for Cardiovascular Angiography and Interventions (SCAI) scientific sessions.
Percutaneous endovenous intervention (PEVI) has been shown as an effective tool in the treatment of acute proximal deep vein thrombosis (DVT) and the sequelae associated with it, according to the study’s lead author Mohsen Sharifi, MD, from Arizona Cardiovascular Consultants in Mesa, Ariz., who added that endovenous stenting is part of therapeutic armamentarium.
Yet, data are lacking on the outcome of stents placed in the femoropopliteal veins. Therefore, the researchers embarked to assess the efficacy and safety of stenting in the femoropopliteal veins in the setting of DVT and compare it with balloon venoplasty in a randomized fashion.
Patients with high grade residual stenosis of greater than 70 percent after PEVI were randomized to receive stenting (stent group, 71 patients) or balloon venoplasty alone (control group, 70 patients).The mean follow-up was 35 months.
All participants underwent venous duplex scanning every six months or sooner if symptomatic. Those with suspicion of redevelopment of DVT underwent repeat venography with intravascular ultrasound (IVUS) evaluation.
There were six patients of the stent group and 15 of the control group, who underwent venography and IVUS for presumed DVT. The researchers found DVT in 4 percent and 10 percent of the patients, respectively.
Sharifi reported that DVT was “asymptomatic” in most patients in the stent group and “mildly symptomatic” in the control group. The mechanism of stent thrombosis was thrombus extension and external compression due to venosclerosis.
He also said that there was no neointimal proliferation as the cause of stent stenosis. There were no stent fractures, extrusion or perforation.
Stent thrombosis occurred in 4 percent of cases and is not due to neointimal proliferation, according to the researchers. “It does not occur independently and is usually an extension of DVT in the adjacent venous segments with high grade stenosis—inflow or outflow obstruction,” Sharifi said. “External compression is an important factor in preventing full stent expansion.”
The researchers concluded that stenting is superior to balloon venoplasty alone.
"We are encouraged by these study results," said Sharifi. "For patients with DVT, stenting is a viable option, as demonstrated by the success rates for patients studied in this trial."