The Micro Neuro-stent will be specifically designed for intracranial vessel implant. The intracranial arteries are 8x thinner than coronary vessels and far more susceptible to damage by instrumentation. These vessels require devices engineered specifically for this application, having more flexibility and more delicate stenting action than a coronary counterpart. To this effect, our neuro-stent is approximately half the thickness of a coronary stent and has a larger expandability ratio. The cell size and the struts are approximately a third of the size of the average coronary stent design. What makes these features possible is the vapor-deposited alloy characteristics. Our basic manufacturing process, physical vapor deposition (PVD), yields a material of higher purity and, therefore, homogeneous crystal arrangement and structure. Vapor deposited alloy has superior metallurgical characteristics allowing for micromachining which is impossible with conventional medical grade tubing.
Our coronary stent will include our technology platform that will be used for our neuro-stent: Vapor-deposited material and micro-engineering of the flow surface. Either self-expanding or balloon-expandable platforms will carry or patented parallel grooves in the inner surface for accelerated healing. The mechanical characteristics of the stent will be optimized, thanks to the superior qualities of our vapor deposited material. Higher alloy strength will allow for lower profiles, while radiopacity will be enhanced by the unique flexibility PVD has in introducing high atomic weigh components into the material. Low profile designs, high purity materials free of contaminants, and the micro-grooved flow surface will result in improved performance over conventional bare metal stents (BMS) while avoiding the threat of late adverse effects associated with polymer covers and drugs. In other words, our coronary stent will have all the advantages of the BMS, including the avoidance of long-term anti-thrombotic medication and the proven long-term reliability -- in addition to the improved short-term performance of our platform.
The Palmaz Scientific all metal micromesh stent is composed of a frame and a micromesh metal cover for highly embologenic applications. The cover is a less than 5 micron nitinol film etched by laser and micro-welded on the frame. The openings in the axially expandable mesh, approximately 100 microns wide, prevent fragments of friable plaque material from embolizing downstream. This is a limitation in angioplasty-stenting of coronary artery bypass graft (CABG), carotid bifurcation and renal arteries, where significant embolic complications are associated with vascular instrumentation. Currently, we believe that there is no thin-film device for pre-emptive embolic protection such as our covered stent.
The struts of a bare metal or drug eluting stent dig into the plaque material on the walls of the vessel after deployment, producing an inflammatory injury. DES has an added problem as cells do not attach to polymers as readily as they do to high purity metals, and over time polymers may become brittle, crack and create voids in cell layer coverage on the stent surface.
The injury and inflammation cause proliferative restenosis, leading to loss of the luminal diameter gained from the stent procedure.