Helical Centerline Stent Improves Patency

Peripheral arterial disease (PAD) is common and expensive; in the United States alone, Medicare-funded inpatient costs in 2001 were estimated at $4.4 billion. The superficial femoral artery (SFA) is the most frequently involved segment in symptomatic PAD, irrespective of sex or race. Although endovascular intervention in the SFA is generally considered safe and efficacious, simple angioplasty has a poor outcome in the majority of patients. In a review of the outcome in the angioplasty control arm of 3 femoropopliteal stenting studies that resulted in Food and Drug Administration approval, the 12-month vessel patency after angioplasty of lesions 4to 15-cm long was only 28%. Initial attempts to improve outcome using nondedicated stents proved futile. Although contemporary dedicated nitinol stents have shown benefit over simple angioplasty and are now widely used to treat occlusive disease of the femoropopliteal artery, the 12-month patency remains far from ideal. Furthermore, when drug-coated balloons are used primarily to treat disease in this area, there will still be a need for stents to treat suboptimal results. Arterial geometry is commonly helical, generating swirling flow, which is known to elevate wall shear. Atherosclerosis and intimal hyperplasia (IH) mainly occur at locations where wall shear is low. A stent that can deform the vessel centerline into a helix has previously been demonstrated in a porcine model to reduce neointimal hyperplasia through mechanisms, including the elevation of wall shear. The purpose of the Mimics trial was to evaluate the safety and effectiveness of the BioMimics 3D helical stent (Veryan Medical Ltd, Horsham, United Kingdom) in the treatment of symptomatic PAD affecting the femoropopliteal artery.