The EverFlex self-expanding peripheral stent system from Medtronic has been proven to provide sustained patency in the treatment of long, complex lesions in the superficial femoral and popliteal arteries, according to the three-year results of the DURABILITY II study, which are reported in Catheterization and Cardiovascular Intervention.
EverFlex is a nitinol stent system that expands to a predetermined diameter to re-open stenotic regions of the superficial femoral artery and proximal popliteal arteries that supply blood to the legs. Narrowing of these arteries is associated peripheral arterial disease.
“DURABILITY II is the first controlled study to focus on treating long, complex lesions, and to specifically test the use of a single nitinol stent in the superficial femoral artery,” said Krishna J Rocha-Singh, chief scientific officer, Prairie Heart Institute, Springfield, USA. “After 36 months, the durable patency and low fracture rates support the validity of a single stent strategy.”
DURABILITY II, a prospective, multicentre, non-randomised, single-arm study, enrolled 287 patients at 44 centres in the USA and Europe. The mean lesion length was 8.9cm and included 48.1% occluded arteries with 43.2% severely calcified lesions. Subjects were followed annually for three years with independent ultrasound core lab adjudicated duplex ultrasound to determine stent patency, radiograms of the stented extremity to assess stent fractures and ankle brachial indices.
Duplex ultrasound-assessed patency (PSVR <2.0) rate at three years was 60%; freedom from loss of primary patency was significantly higher for lesions <=8cm at 71%, compared to lesions >8cm at 50.5% (p=0.0001). The three year freedom from target lesion revascularisation was 70%. The three-year stent fracture rate was 0.9%.
“Restenosis and stent fractures are concerns when treating long lesions in the superficial femoral artery and proximal popliteal arteries,” said Mark Turco, medical director for the Aortic and Peripheral Vascular business, which is part of the Cardiac and Vascular Group at Medtronic. “In the DURABILITY II study, the use of a single long stent demonstrated the ability to achieve long-term vessel patency, while minimising the need for re-interventions.”