1. Field of the Invention
The present invention generally relates to expandable endoprosthesis devices, in particular expandable intraluminal vascular grafts, generally called stents, which are adapted to be implanted into a patient's lumen, such as a blood vessel, to maintain the patency of the vessel. These devices are frequently used in the treatment of atherosclerotic stenosis in blood vessels, especially after percutaneous transluminal coronary angioplasty (PTCA) procedures, to prevent restenosis of a blood vessel. The present invention also relates to an expandable intraluminal vascular graft that can be used in any body lumen, and be used for drug delivery.
2. Description of Related Art
In expandable stents that are delivered with expandable catheters, such as balloon catheters, the stents are positioned over the balloon portion of the catheter and expanded from a reduced diameter to an enlarged diameter greater than or equal to the artery wall, by inflating the balloon. Stents of this type can be expanded and held in an enlarged diameter by deformation of the stent (e.g., Palmaz U.S. Pat. No. 4,733,665), by engagement of the stent walls with respect to one another (e.g., Kreamer U.S. Pat. No. 4,740,207; Beck et al. U.S. Pat. No. 4,877,030; and Derbyshire U.S. Pat. No. 5,007,926), and by one-way engagement of the stent walls together with endothelial growth into the stent (e.g., Stack et al. U.S. Pat. No. 5,059,211).