Abstract: A non-radioactive metallic stent is coated with a biodegradable or non-biodegradable thin coating of less than about 100 microns in thickness selected to avoid provoking any foreign body reaction. The coating contains a radioactive source of beta emitting properties for irradiation of tissue when the stent is implanted in a blood vessel treated by angioplasty, to inhibit proliferation of smooth muscle cells in response to trauma to the wall of the blood vessel from the angioplasty, and thereby prevent restenosis of the vessel. The stent coating incorporating the radioactive source constitutes a first layer atop the surface of the stent, and the coating further includes a second layer incorporating an anti-coagulant substance to inhibit early thrombus formation of the stent. The second layer is adhered to and atop the first layer. The composite layer of the coating has a thickness of less than about 100 microns. The activity level of the radioactive source is approximately one microcurie.
Abstract: A stent is adapted for deployment at a preselected site in a duct within the body of a patient to inhibit the lumen of the duct at that site from narrowing to a point that resists passage through the lumen. The stent is a generally cylindrical open-ended element having a perforated self-supporting sidewall of substantially uniform thickness adapted to be selectively expanded radially when the stent is to be deployed, to engage the wall of the duct and to resist radial contraction under forces exerted on said sidewall by the wall of the duct in the region of the engagement. The sidewall has greater rigidity in the midsection of the length of the cylindrical element and greater flexibility at each end thereof, by virtue of its having a composite design of different patterns, each pattern being a network of interconnected links with openings therebetween that determine the relative rigidity and flexibility of the sidewall along the length of the cylindrical element.
Abstract: A vascular or endoluminal stent adapted for deployment in a vessel or tract of a patient to maintain an open lumen therein is formed from a metal open-ended tube which is the single component of the stent. The tube has a multiplicity of holes cut by laser through its wall. The through-holes are encompassed by serpentines that constitute the wall, the serpentines extending sinusoidally each in multiple 360.degree. wavelengths in a single turn about the axis of the tube and juxtaposed in plural substantially identical segments disposed with regularity along the axis. Each segment has a length equal to the distance between crests and troughs of the sinusoid. Adjacent serpentines are joined together at crest and trough, respectively, so that their interconnections are 180.degree. out of phase relative to their wavelength.
February 14, 1996
Date of Patent:
December 1, 1998
Inflow Dynamics Inc.
Eckhard Alt, Thilo Fliedner, Robert Alter, Axel Stemberger
Abstract: A vascular or endoluminal stent is adapted for deployment in a vessel or tract of a patient to maintain an open lumen therein. The stent includes a biocompatible metal hollow tube having a multiplicity of openings through an open-ended tubular wall thereof, the tube constituting a single member from which the entire stent is fabricated, and a thin, tightly adherent layer of gold overlying the entire exposed surface area of the tube including edges of the openings as well as exterior and interior surfaces and ends of the wall. The layer may include at least a trace of another noble metal to improve the adherence of the layer to the underlying metal surface of the tube. Plural tightly bonded films superposed one atop another may be used to form a composite layer, but in any event the overall layer has a thickness in a range from approximately 1 micron to approximately 20 microns.
Abstract: A method is disclosed for coating a biomaterial to be placed in contact with a patient's blood flow to inhibit blood coagulation from adhering to the biomaterial that would otherwise result from such contact. A biodegradable material of liquid state compatible with the blood and tissue of the human body is prepared, and an anti-coagulant drug is incorporated into the liquid state of the biodegradable material to form a liquid coating material. The liquid coating material is adhesively applied to a surface of the biomaterial in a substantially continuous overlying layer having a formulation, pattern and thickness selected according to the period of time over which the coating material is to perform its anti-coagulant action. Thereafter the coating material is dried to a layer thickness less than about 100 microns for continuous disintegration thereof as a function of time when the layer is in contact with flowing blood.