Lower extremity peripheral arterial disease (PAD) represents a significant disease burden in the United States with over 10 million Americans suffering from its effects. Also known as hardening of the arteries, PAD is a common circulatory problem in which narrowed arteries reduce blood flow to the limbs. The condition is considered to be a red flag for vascular disease, heart attack and stroke, and its progression can result in loss of limb and death. Current treatments for PAD include balloon angioplasty, placement of a covered or open stent, and open bypass surgery. Unfortunately, no treatment has proven to be completely successful in the treatment of PAD. In the case of the latter two, in-stent or graft thrombosis (i.e. clot formation at the site of device implantation that prevents blood flow) are commonly encountered and thus present serious complications. Therefore, a critical need exists for developing endovascular technology to treat PAD that is non-thrombogenic or at least comparable to vein grafts, which remain the gold standard for revascularizing complicated lesions of the lower extremity.
Our group has been examining the utility of covering stents with surface treated thin film nickel titanium to treat a wide range of vascular disease processes. Nitinol is a biologically inert material that is already used in many medical applications due to its superelastic properties. Part of its biocompatibility can be attributed to the formation of a titanium oxide (TiO2) surface layer that prevents the diffusion of Ni atoms into the blood stream while also keeping it relatively non-thrombogenic. Using a UCLA patented process, our group can create thin film nitinol made to uniform thicknesses as small as one micron. This ultra low-profile, smooth, and non-thrombogenic material is ideally suited to be used in small-diameter peripheral vessels.
Our UCLA research team was recently awarded a $1 million Challenge Grant from the National Institute of Health to conduct further work into the unique properties of thin film nitinol covered stents.