Abstract: An expandable tubular endoluminal prosthesis for maintaining the patency of a bodily vessel has a plurality of axially spaced serpentine bands. Each serpentine band has a proximal and distal end and a plurality of interconnected struts. Serpentine bands which are adjacent one another are connected one to the other. The prosthesis has a flow path therethrough and is capable of radial outward expansion from a first diameter to a second enlarged diameter. In a cross-section perpendicular to the flowpath, the struts have thicker portions with a narrower portion therebetween and have a greater width than thickness.
August 17, 2006
January 11, 2007
INFLOW DYNAMICS INC.
Eckhard Alt, Thilo Fliedner, Robert Alert, 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. The stent constitutes a scaffold formed from a single open-ended tube having a multiplicity of through-holes in its wall. The through-holes are defined by a plurality of struts that bound the holes. Each of the struts has an optimized cross-section of oval shape with a long diameter generally aligned with the length or circumference of the tube wall and a short diameter generally aligned with the thickness of the tube wall. The oval shape of the struts provide several advantages including enhancing flexibility of the stent, easing advancement of the stent through a lumen of the vessel or tract for deployment at a target site therein, protecting the balloon of a balloon catheter on which the stent is tightly crimped, and enhancing expansion of the stent during deployment while maintaining its capability to withstand compression in response to recoil of the vessel or tract following deployment.
Abstract: In a process of fabricating a stent composed primarily of niobium alloyed with a trace amount of zirconium, tantalum, or titanium for hardening, the stent is annealed under vacuum in a substantially oxygen-free environment. The vacuum is preferably maintained at pressure less than 10?4 millibars, oxygen-content less than about 80 parts per million, and the annealing temperature exceeds 400° C. for at least one hour, and is preferably kept in a range from about 1100–1200° C. for several hours. This may be followed by applying a surface layer of oxide, such as iridium oxide, with a thickness of 299–300 nm to the stent.
Abstract: A stent is adapted to be implanted in a duct of a human body to maintain an open lumen at the implant site, and to allow viewing body tissue and fluids by magnetic resonance imaging (MRI) energy applied external to the body. The stent constitutes a metal scaffold. An electrical circuit resonant at the resonance frequency of the MRI energy is fabricated integral with the scaffold structure of the stent to promote viewing body properties within the lumen of the stent.
February 8, 2001
Date of Patent:
July 27, 2004
Inflow Dynamics Inc.
Eckhard Alt, Torsten Scheuermann, Michael Kühling
Abstract: A catheter having a distal end for insertion into a lumen of a patient's body includes a deployable semi-permeable membrane for trapping debris dislodged by a stent while allowing perfusion of body fluid through the membrane, mounted distally on said catheter; a stent mounted proximally of the membrane on the catheter; and a deployment system on the catheter for deploying the membrane in advance of deploying the stent. The deployment system is common to both the membrane and the stent. It includes a respective deployment balloon for each of the membrane and the stent. Deployment of the membrane in advance of the stent is controlled by differences in pressure-diameter characteristics of the respective deployment balloons. The deployable semi-permeable membrane is a selectively controllable collapsible mechanism.
Abstract: A vascular or endoluminal stent is adapted to be implanted in a vessel, duct or tract of a human body to maintain an open lumen at the site of the implant. The sidewall of the open-ended tubular structure of the stent is a base layer of a metal biologically compatible with blood and tissue of the human body. An intermediate metal particle layer of substantially greater radiopacity overlies the base layer, with particles bonded to the base layer and to each other to leave interstices therebetween as a repository for retaining and dispensing drugs or other agents for time release therefrom after the stent is implanted, to assist the stent in maintaining the lumen open. The particles are composed primarily of a noble metal—an alloy of platinum-iridium. The sidewall has holes extending therethrough, and the particle layer resides along the outward facing and inward facing surfaces, and the edges of the through holes and open ends of the sidewall.
August 29, 2003
February 26, 2004
Inflow Dynamics, Inc., a Delaware corporation
Abstract: In a process for producing a biocompatible stent, a tubular substrate of the stent adapted for diametric expansion has a layer of a noble metal oxide formed over at least the outer surface of greater diameter of the substrate, the substrate being composed of a metal or an alloy thereof that is non-noble or less-noble than the layer's noble metal. An interface region adapted to prevent corrosion and to provide a firm bond between the surface of the substrate and the noble metal oxide layer is established, at least in part, by forming the noble metal oxide layer with a progressively varying concentration of noble metal-to-oxide with depth of the layer such that a surface of pure noble metal and negligible oxide of the layer is in closest proximity to the surface of the substrate. In one embodiment of the process, the interface region is established by forming the surface of pure noble metal and negligible oxide thereof in direct contact with the metal or alloy of the substrate surface.
Abstract: In a process of fabricating a stent composed primarily of niobium alloyed with a trace amount of zirconium, tantalum, or titanium for hardening, the stent is annealed under vacuum in a substantially oxygen-free environment. The vacuum is preferably maintained at pressure less than 10−4 millibars, oxygen-content less than about 80 parts per million, and the annealing temperature exceeds 400° C. for at least one hour, and is preferably kept in a range from about 1100-1200° C. for several hours. This may be followed by applying a surface layer of oxide, such as iridium oxide, with a thickness of 299-300 nm to the stent.
Abstract: A stent is composed of a single homogeneous tubing of niobium with a trace of additional metal less than about 5%, preferably zirconium, for alloy formation and reinforcement. The stent surface is provided with at least a partial coating to inhibit closure of a central lumen at a site of stent implant in the body. The surface coating may be vapor deposited or plasma deposited and comprises iridium oxide, titanium nitrate, a blend of metals, or surface oxidation of the niobium. The stent may have a rough surface characteristic.
Abstract: A vascular or endoluminal stent has low surface friction for ease of navigating a vessel, duct or tract of a patient. The stent is configured as a tubular element of biocompatible material having a longitudinal axis, open ends and a multiplicity of openings of generally common shape and size through its wall throughout its length. The openings are bounded by a network of tangentially interconnected, continuous, predominantly longitudinally oriented curvilinear struts, without discontinuity, forming a sidewall of the tubular element. The stent is adapted to be deployed by exertion of outward radial pressure on the tubular element, and when deployed, at least a segment of each strut undergoes a transition to a predominantly transverse orientation relative to the longitudinal axis of the stent.
Abstract: A stent has a tubular metal base adapted to be expanded from a first vessel-navigable diameter to a larger second vessel-deployed diameter; a thin, continuous intermediate layer of noble metal or alloy thereof selected from a group consisting of niobium, zirconium, titanium and tantalum, overlying and tightly adherent to an exposed surface area of the tubular metal base; and a biocompatible outer layer of iridium oxide overlying and adherent to the intermediate layer. The outer layer has a relatively rough surface with interstices into which beneficial drugs or other substances or agents may be infused, with or without a biodegradable carrier, to preclude occlusion from restenosis or thrombosis during the acute stage following deployment of the stent.
Abstract: A stent of high longitudinal flexibility includes multiple ring elements coupled together to be articulating without fixed physical attachment therebetween when the stent is in an unexpanded state, and to uncouple automatically while maintaining their positional relationship when the stent is deployed to an expanded state. The stent is fabricated to offer radial strength suitable for supporting a wall of a vessel, duct or tract of a patient in which the stent is to be implanted, against recoil of the wall in response to deployment of the stent. The fabrication process includes forming a plurality of common ring elements aligned along a longitudinal axis; and fashioning coupling elements on each of the ring elements to mate with and pivot longitudinally relative to coupling elements fashioned on neighboring ring elements without fixed physical attachment between the coupling elements.
Abstract: A method of forming an iridium oxide coating on a metal stent to achieve a firmattachment of a thin biocompatible coating of the iridium oxide such that the iridium oxide resists being dislodged from the stent upon expansion thereof in a vessel of the human body during implantation of the stent. The method includes submerging the stent in a coating solution having an adequate concentration of iridium chloride in a suitable liquid vehicle, and subjecting the coating solution with stent immersed therein to combined heating and application of ultrasonic energy at a temperature and energy level and for a time interval sufficient to form a coating of iridium oxide of desired thickness and surface roughness on the underlying metal surface of the stent.
Abstract: A stent delivery system is sized to allow it to traverse small-sized vessels of diameter in a range from about 1.25 mm to less than about 2.5 mm in a human body. The delivery system includes a balloon which has an inflated diameter less than 2.5 mm at nominal pressure and is integrated distally on a catheter for selective inflation and deflation through a lumen of the catheter. The stent is adapted to be mounted on the uninflated balloon so that the combination of the balloon when uninflated and the stent mounted thereon has a crossing profile in a range from approximately 0.5 mm to approximately 0.8 mm, to enable the delivery system to rapidly traverse the small-sized vessel for subsequent deployment of the stent at a preselected target site of the vessel. At the target site, the balloon is inflated to expand the diameter of the stent to lodge against the wall of the vessel and remain in place when the balloon is deflated and the delivery system is withdrawn from the vessel.
Abstract: A non-radioactive metallic stent is coated with a biodegradable thin coating of less than about 100 microns in thickness selected to avoid provoking any foreign body reaction. The biodegradable material in the coating disintegrates over time in the presence of body fluid. The coating contains a radioactive source of, for example, a beta radiation emitter 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 to prevent rapid tissue growth and consequent restenosis of the vessel. The stent coating incorporating the radioactive source constitutes a first layer adherent to and overlying the surface of the stent. The coating may further include a second layer atop the first layer, incorporating an anti-coagulant substance to inhibit thrombus formation on the stent.
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.
November 5, 1998
Date of Patent:
December 12, 2000
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 constituting a base layer 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 intermediate layer of noble metal 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. A third, outermost ceramic-like layer composed of an oxide, hydroxide or nitrate of a noble metal is formed atop and in adherent relation to the intermediate layer.
Abstract: A stent delivery system includes a catheter having a balloon mounted at its distal end for advancement into and withdrawal from a patient's vascular system by manipulation of the catheter from a point external to the patient's body, a lumen extending through the catheter into the balloon to allow the balloon to be selectively inflated and deflated from a pressurizing medium external to the patient's body, and spaced-apart radiopaque projections on the catheter adjacent the proximal and distal ends of the balloon to receive and retain a stent therebetween in overlying relation to the balloon and to provide x-ray markers thereof. The stent is deployed at a designated target site by selectively inflating the balloon to radially expand the diameter of the stent against the vascular wall.