A bioresorbable vascular scaffold that restores blood flow, releases an antirestenotic drug and dissolves within two years has been used for the first time in the treatment of critical limb ischaemia in Europe. Will this innovation offer new hope in revascularisation below the knee?
The first patient was enrolled into the ABSORB BTK trial by Marc Bosiers, head of the Department of Vascular Surgery at St Blasius Hospital in Dendermonde, Belgium. “The intervention with the absorbable stent was uncomplicated and went smoothly. After six months, the patient is doing well,” he told Vascular News.
ABSORB BTK is an international clinical trial evaluating the safety and efficacy of the Absorb bioresorbable vascular scaffold, from Abbott Vascular, for the treatment of below-the-knee critical limb ischaemia patients. Absorb restores blood flow by opening a blocked vessel, providing support to the vessel until the device dissolves within approximately two years. The device releases the antirestenotic drug everolimus. Dierk Scheinert, University of Leipzig, Germany, is the principal investigator of the trial. The primary endpoint is freedom from major adverse limb events (major amputation or major re-intervention) occurring within one year or periprocedural (30-day) death. Follow-up is scheduled at one, six and 12 months and at two and three years.
“The Absorb device represents the next generation in revascularisation therapies that may hold promise for patients with vessel disease in the lower leg. With the ABSORB BTK trial, we will test whether this novel approach – restoring blood flow with a temporary scaffold – has the potential to improve the outcomes of patients with critical limb ischaemia,” Scheinert said.
The Absorb device is made of polylactide, a biocompatible material that is commonly used in medical implants such as dissolvable sutures. Because a permanent metallic implant is not left behind, naturally occurring vessel functions may be restored. The device is 3mm x 28mm.
In January 2011, the Absorb device received the CE mark for the treatment of coronary artery disease. Absorb is currently under development and is not available for sale in the USA.
In the coronary arteries, four-year follow-up results for 29 patients have shown a major adverse events rate of 3.4% without any late complications such as stent thrombosis. Clopidogrel therapy had been discontinued in all patients.
The ABSORB BTK single-arm trial will enrol 90 patients with up to two de novo lesions in separate tibial vessels, length ≤24mm, at up to 10 clinical trial sites in Europe and New Zealand. The primary endpoint is a composite of freedom from major adverse limb events (major amputation or major re-interventions) within one year or death within 30 days of the procedure.
Vascular News has learnt that Andrew Holden has recently performed the first-in-man experience with a bioabsorbable stent (480 Biomedical) for the treatment of superficial femoral artery lesions. The first results are set to be presented at the Charing Cross Symposium (14–17 April 2012) in London, UK.