Abstract: The invention provides a process by which tubular tissue supports (stents) can be removed from hollow organs of humans or of animals after heating to a temperature below the transition temperature Ttrans until softening occurs.

Abstract: Methods and systems of delivering a stent at an elevated temperature are disclosed herein.

Abstract: A medical device-includes a polymer stent crimped to a catheter having an expansion balloon. The stent is crimped to the balloon by a process that includes heating the stent to a temperature below the polymer's glass transition temperature to improve stent retention without adversely affecting the mechanical characteristics of the stent when later deployed to support a body lumen.

Abstract: Articles made of shape memory alloys having improved fatigue performance and to methods of treating articles formed from shape memory alloy materials by pre-straining the articles (or desired portions of the articles) in a controlled manner so that the resultant articles exhibit improved fatigue performance. The shape memory articles are preferably medical devices, more preferably implantable medical devices. They are most preferably devices of nitinol shape memory alloy, most particularly that is superelastic at normal body temperature. The pre-straining method of the present invention as performed on such articles includes the controlled introduction of non-recoverable tensile strains greater than about 0.20% at the surface of a desired portion of a shape memory alloy article. Controlled pre-straining operations are performed on the shape-set nitinol metal to achieve non-recoverable tensile strain greater than about 0.20% at or near the surface of selected regions in the nitinol metal article.

Abstract: A process to load a medical device comprising a shape memory material into a delivery system is described herein. According to one aspect, the method includes applying a force to the medical device to obtain a delivery configuration thereof, where the device is at a first temperature within an R-phase temperature range of the shape memory material during application of the force. The medical device is cooled in the delivery configuration to a second temperature at or below a martensite finish temperature of the shape memory material. The force is then removed from the medical device, and the device is loaded into a delivery system. Preferably, the medical device substantially maintains the delivery configuration during the loading process.

Abstract: A stent made of nitinol having improved axial or radial stiffness, the stent having a support structure which comprises peripheral struts around the circumference, wherein the peripheral struts are linked to one another in the axial direction via connection struts. The support structure may assume a first compressed state and a second expanded state. The nitinol is in the support structure in a martensitic microstructure in the compressed state and largely in an austenitic microstructure in the second expanded state. One or more support structure sections, however, are entirely or partially in a martensitic microstructure in the second expanded state.

Abstract: A guide wire includes a distal core member made of a ferrous alloy which has shape memory properties and superelasticity. The ferrous alloy preferably includes substantially two phases, and has a difference of 100° C. or less between an Af point and an Ms point in a thermal hysteresis of martensitic transformation and reverse transformation. The guide wire may include a proximal core member made of an iron-containing alloy and having a higher modulus of elasticity than the distal core member. The two core members may be joined together by welding to form a core of the guide wire.

Abstract: A stent includes a coiled-up sheet having overlapping inner and outer longitudinal sections extending parallel to a longitudinal axis thereof, and defining a periphery, the coiled-up sheet being unrollable between contracted and enlarged conditions. A plurality of stretchable elements are formed in the coiled-up sheet, the stretchable elements being expandable about the periphery between an unstretched condition to facilitate placement in a delivery device in the contracted condition and a stretched condition to facilitate expansion of the coiled-up sheet to the enlarged condition upon deployment from the delivery device. Preferably, the coiled-up sheet is biased to the enlarged condition, and the stretchable elements are biased to the stretched condition. More preferably, at least one of the biases is provided by a shape memory property of the coiled-up sheet, which is activated by exposing the stent to body temperature.

Abstract: Described herein are devices and methods fabricating devices having nanostructures that allow adhesion or growth of one cell type, such as endothelial cells, more than another cell type, such as smooth muscle cells. In particular, stent covers having such nanostructures are described, and methods for fabricating these stent covers. Also described herein are methods for optimizing the nanostructures forming the devices.

Abstract: This invention relates to medical devices comprising shape memory alloys which have been subjected to a thermal and mechanical treatment to increase the austenite start temperature As to As? such that the shape memory alloy is martensitic at body temperature and when subsequently subjected to a controlled deformation, the shape memory alloy preferentially reverts to the parent phase. The shape memory alloy comprises nickel, titanium and a ternary element, preferably 3 at. % to about 20 at. %. The ternary element is insoluble in a Ni—Ti matrix. In a preferred embodiment, the element is selected from the group consisting of niobium, tantalum and zirconium.

Abstract: A method of crimping a stent to a support element is disclosed, the method comprising: positioning a polymeric stent around a support element; heating the stent, wherein the heated stent is above ambient temperature; and allowing the heated stent to radially contract onto the support element, wherein the heated stent radially contracts at least partially due to heating the stent.

Abstract: A method of loading a medical device into a delivery system includes providing a two-stage shape memory alloy at a temperature at which at least a portion of the alloy includes austenite. A stress which is sufficient to form R-phase from at least a portion of the austenite is applied to the medical device at the temperature. A delivery configuration of the medical device is obtained, and the medical device is loaded into a restraining member. Preferably, the delivery configuration of the medical device includes stress-induced R-phase.

Abstract: A stent for treating a physical anomaly. The stent includes a skeletal support structure for expanding in the physical anomaly and a shape memory material coupled to the skeletal support structure.

Abstract: Methods and systems of delivering a stent at an elevated temperature are disclosed herein. Methods of delivering a stent include allowing reactants to react within a delivery system exothermically. The heat generated from the exothermic reaction increase a temperature of a stent mounted on a support member. The increase in temperature increases the flexibility of the stent which reduces or eliminates formation of cracks in the stent when it expands. A system can include a first reactant disposed within at least a portion of the support member, a catheter in fluid communication with the support member, or both. The first reactant being disposed in such a way to react exothermically with a second reactant disposed within the delivery system.

Abstract: A process for assembling a medical device made from a nickel-titanium alloy for use in a mammalian body while avoiding the formation of stress-induced martensite and a medical device used in combination with a delivery system for deployment into the mammalian body are disclosed. By heating the nickel-titanium alloy of the medical device to a temperature above Md, and deforming and installing the device into a delivery system or holding capsule, it is possible to avoid the formation of stress-induced martensite in the stent, which stays in the austenitic phase throughout.

Abstract: Venous filters having at least two struts (110) each having a connected end and a non-connected end, wherein each of the struts includes a strut portion and an anchor portion (116), and wherein the strut portion and the anchor portion are attached via an electrolytically active thread (221, 222); and a head (118) that connects the connected ends of the struts, wherein the strut portion can be separated from the anchor portion at least in part by the application of an electrical current. The invention also includes a venous filter having at least two struts, wherein each of the struts includes a temperature sensitive portion and an anchor portion; wherein the anchor portion is separated from the temperature sensitive portion at least in part by changing the temperature around at least the temperature sensitive portion.

Abstract: Medical dilatation balloons comprise a polymer that has the attribute of memory, and/or is crosslinked to impart memory. Such balloons exhibit a reduced tendency to overinflate at high inflation pressures. Furthermore, such balloons when shrunk radially by the application of heat while restraining axial shrinkage, exhibit customizable linear or non-linear compliance curves and lower crosslinking profile relative to the same balloon when unshrunk. Also disclosed is an expansive element within a tube whose outer diameter is equal to the outer diameter of the tube from which it was made. In addition, disclosed are (a) processes for preparing crosslinkable polymers, (b) joining crosslinked balloons to catheter systems, (c) forming shrunk balloon elements, and (d) forming an expansive element within a tube whose outer diameter is equal to the outer diameter of the tube from which it was made.

Abstract: A method of crimping a stent to a support element is disclosed, the method comprising: positioning a polymeric stent around a support element; heating the stent, wherein the heated stent is above ambient temperature; and allowing the heated stent to radially contract onto the support element, wherein the heated stent radially contracts at least partially due to heating the stent.

Abstract: A vacuum deposition method for fabricating high-strength nitinol films by sputter depositing nickel and titanium from a heated sputtering target, and controlling the sputter deposition process parameters in order to create high-strength nitinol films that exhibit shape memory and/or superelastic properties without the need for precipitation annealing to attenuate the transition conditions of the deposited material. A vacuum deposited nitinol film having high-strength properties equal to or better than wrought nitinol films and which are characterized by having non-columnar crystal grain structures.

Abstract: A radiopaque nitinol stent for implantation in a body lumen is disclosed. The stent is made from a superelastic alloy such as nickel-titanium or nitinol, and includes a ternary element including tungsten. The added tungsten in specified amounts improve the radiopacity of the nitinol stent comparable to that of a stainless steel stent of the same strut pattern coated with a thin layer of gold. Furthermore, the nitinol stent has improved radiopacity yet retains its superelastic and shape memory behavior and further maintains a thin strut/wall thickness for high flexibility.

Abstract: Devices and methods of making devices having one or more components made of single crystal shape memory alloy capable of large recoverable distortions, defined herein as “hyperelastic” SMA. Recoverable Strains are as large as 9 percent, and in special circumstances as large as 22 percent. Hyperelastic SMAs exhibit no creep or gradual change during repeated cycling because there are no crystal boundaries. Hyperelastic properties are inherent in the single crystal as formed: no cold work or special heat treatment is necessary. Alloy components are Cu—Al—X where X may be Ni, Fe, Co, Mn. Single crystals are pulled from melt as in the Stepanov method and quenched by rapid cooling to prevent selective precipitation of individual elemental components. Conventional methods of finishing are used: milling, turning, electro-discharge machining, abrasion. Fields of application include aerospace, military, automotive, medical devices, microelectronics, and consumer products.

Abstract: A medical device has a structure differentiated in terms of its stiffness or elasticity. Such stiffness differentiation is achieved through the use of superelastic or shape-memory materials which transition between a relatively malleable phase to a stiffer phase at a transition temperature which is adjustable by heat treatment. A differentiation of the stiffness of the structure forming the medical device is achieved by differentially adjusting the transition temperature of select portions of the medical device before the medical device is placed in its operational mode, usually implanted in a body at body temperature.

Abstract: The invention concerns a micro-muscle designed to be immersed in a biological liquid, comprising a deformable chamber whereof one portion at least consists of a semipermeable membrane, said chamber containing a solution capable of osmotic activity. The solution is preferably activated by a product to be injected into the biological liquid.

Abstract: Medical devices for in vivo medical applications are disclosed. The medical devices are constructed of shape memory polymer (SMP) materials capable of assuming a memory shape at physiological temperatures. These medical devices may be used in surgical procedures and in both vascular and non-vascular applications. These SMP medical devices have a post-implantation memory shape that is substantially identical to or slightly larger than the insertion site to adapt to vessel growth or size changes. SMP medical devices may be formed as stents or occlusion devices (i.e., plugs) having a number of different structural features. The SMP medical devices may be formed from a first monomer and a second cross-linking monomer, wherein the weight percentages of the first and second monomers are selected by performing an iterative function to reach a predetermined glass transition temperature (Tg) and a predetermined rubbery modulus to optimize post-implantation memory shape properties of the devices.

Abstract: The object of this invention is to provide a stent for high frequency thermotherapy, which is fabricated by knitting first superlastic shape-memory alloy wires as a way to allow the first superelastic shape-memory alloy wires to cross each other at different positions to make a hollow cylindrical stent body having a net structure with a plurality of meshes. The stent body is covered with an insulating substance. A hollow cylindrical conductive body surrounds a waist part of the stent body while any one end or both ends of the conductive body is attached to the waist part of the stent body. At this time, the conductive body is fabricated by knitting second superelastic shape-memory alloy wires as a way to allow the second superelastic shape-memory alloy wires to cross each other at different positions.

Abstract: A method of sequentially transitioning a thermally active shape memory device progressively translocates the thermally active shape memory device through a first controlled temperature zone and through an additional controlled temperature zone. The thermally active shape memory device is thermally transitioned and changed in geometric shape as a result of thermal communication of the shape memory device with either or both of the controlled temperature zones to produce a transitioned thermally active shape memory device. Novel devices produced according to the method are also disclosed.

Abstract: A self-contracting stent for use at a treatment site comprising shape memory material is provided. The stent may have an initial diameter for delivery to the treatment site and an expanded diameter when deployed at the treatment site. The stent further may have a contracted diameter when subjected to a temperature at or above a transition temperature. The contracted diameter is less than the expanded diameter and permits repositioning or removal of the stent from the treatment site. Additionally, a method for delivering and recovering the stent from a treatment site is provided. The method includes delivering a stent to a treatment site and expanding the stent at the treatment site so that the stent is deployed at the treatment site. The method further includes changing the temperature of the stent at the treatment site to at least a transition temperature to cause the stent to contract.

Abstract: A modular prosthetic conduit system such as a stent or stent graft system tailored for the repair of aneurysms or other compromised vessel walls. The stent or stent graft system incorporates various means to interlock the multiple modular components used in the repair procedure. The present invention further provides a modular stent graft system tailored for the repair of aneurysms or other compromised vessel walls that cross or are adjacent to a branch or bifurcation in a vessel.

Abstract: The present invention is directed to polymeric compositions comprising a biodegradable copolymer that possesses shape-memory properties and implantable devices (e.g., drug-delivery stents) formed of materials (e.g., a coating) containing such compositions. The polymeric compositions can also contain at least one non-fouling moiety, at least additional biocompatible polymer, at least one biobeneficial material, at least one bioactive agent, or a combination thereof. The polymeric compositions are formulated to possess good mechanical, physical and biological properties. Moreover, implantable devices formed of materials comprising such compositions can be delivered to the treatment site in a conveniently compressed size and then can expand to dimensions appropriate for their medical functions.

Abstract: In one preferred embodiment, a prosthesis is provided that can be selectively expanded by increasing the temperature of the prosthesis within the patient. The prosthesis is composed of a shape memory material that expands when heated to a temperature greater than an average body temperature, allowing the user to selectively heat and therefore expand the prosthesis at a desired location.

Abstract: To improve radiopacity in a stent, and to reduce trauma while improving stent anchoring, imported beads are mounted To stent precursor matrices. Specially attractive is to provide a ring of such beads on the end rings of stent structures featuring a cylindrical mid length section flanked by outwardly flared ends. The beads can be of the same or different material from that of the stent matrix. The beads can assist in drawing the stent into a sleeve of a delivery system. Beads can be used to reveal features of the stent away from an end ring, such as a fenestration in the cylinder. Beads can be fixed in a position mechanically or by welding.

Abstract: In accordance with embodiments of the present invention, a method for preparing a shape memory alloy endoprosthesis, displaying strain induced martensite phenomenon, for delivery includes inserting a shape memory alloy endoprosthesis into a delivery device, inducing a first strain within a first region of the shape memory alloy endoprosthesis, inducing a second strain within a second region of the shape memory alloy endoprosthesis, and sterilizing the delivery device while maintaining the first strain and the second strain induced within the shape memory alloy endoprosthesis. In accordance with other embodiments of the present invention, an apparatus for delivering a shape memory alloy endoprosthesis includes an inner core having a first diameter, an outer body having a second diameter greater than the first diameter, and a calibrated endcap attached to the inner core.

Abstract: A process to load a medical device comprising a shape memory material into a delivery system is described herein. According to one aspect, the method includes applying a force to the medical device to obtain a delivery configuration thereof, where the device is at a first temperature within an R-phase temperature range of the shape memory material during application of the force. The medical device is cooled in the delivery configuration to a second temperature at or below a martensite finish temperature of the shape memory material. The force is then removed from the medical device, and the device is loaded into a delivery system. Preferably, the medical device substantially maintains the delivery configuration during the loading process.

Abstract: A stent formed of polymeric material, useful for the expansion of a lumen and the delivery of one or more therapeutic agents in situ is disclosed. The stent may be multi-layered, and may change shape at a state transition temperature governed by the materials forming the layers. Methods of use and manufacture are also disclosed.

Abstract: An implant comprises a structure that may be implanted into tissue and that has a first material property at normal body temperature. The first material property is variable at elevated temperatures above normal body temperature. The implant also has a plurality of particles dispersed in the structure that are adapted to convert incident radiation into heat energy when irradiated with electromagnetic radiation. The particles are in thermal contact with the structure such that exposure of the particles to incident radiation raises the temperature of the structure thereby changing the first material property relative to the first material property at normal body temperature.

Abstract: A vacuum deposition method for fabricating high-strength nitinol films by sputter depositing nickel and titanium from a heated sputtering target, and controlling the sputter deposition process parameters in order to create high-strength nitinol films that exhibit shape memory and/or superelastic properties without the need for precipitation annealing to attenuate the transition conditions of the deposited material. A vacuum deposited nitinol film having high-strength properties equal to or better than wrought nitinol films and which are characterized by having non-columnar crystal grain structures.

Abstract: A stent for a vessel implanted in the vessel of the living body including a main body portion of the stent formed into a tube by a yarn formed of a biodegradable polymer exhibiting a shape memory function. The main body portion of the stent is shape-memorized to a size that can be inplanted in the vessel. The main body portion of the stent is implanted in the vessel of the living body as it is contracted in diameter by an external force, and is enlarged in diameter by being heated with the temperature of the living body. The main body portion of the stent is formed by winding a yarn formed of a biodegradable polymer in a tube form as the yarn is bent in a zigzag design. The main body portion of the stent is enlarged or contracted in diameter with the bends of the yarn as the displacing portions.

Abstract: An expandable stent and delivery system therefor is provided for treating vascular diseases such as partially occluded blood vessels and aneurysms. The delivery system includes proximal, intermediate and distal cylindrical members disposed about an elongated core member. The proximal, intermediate, and distal cylindrical members are spaced apart such that first and second gaps are formed. The expandable stent includes anchor members which are formed by winding a radiopaque coil onto a threaded portion of a strut member of the expandable stent. The expandable stent is mounted on the intermediate cylindrical member with the anchor members disposed within the gaps between the cylindrical members. A deployment catheter is used to compress and constrain the stent about the intermediate cylindrical member to thereby interlock the stent onto the core member.

Abstract: A stent or other intraluminal medical device may be constructed utilizing a series of split-bridges interposed between a series of fixed bridges to reduce the likelihood of deformation during stent loading and stent deployment without sacrificing overall stent flexibility. The stent comprises a plurality of hoops interconnected by a plurality of fixed bridges. The stent also comprises a plurality of split-bridges, which only make contact when the stent is subjected to compressive axial loading. The stent may also comprise markers formed from housings integral with the stent and marker inserts having a higher radiopacity than the stent. This design provides for more precise placement and post-procedural visualization in a vessel, by increasing the radiopacity of the stent under X-ray fluoroscopy. The housings are formed integral to the stent and the marker inserts are made from a material close in the galvanic series to the stent material and sized to substantially minimize the effect of galvanic corrosion.

Abstract: The invention provides a method of manufacturing a system for treating a vascular condition. A catheter including an inflatable balloon is provided. A stent is positioned over the balloon. An adhesive material is applied between an inner surface of the stent and an outer surface of the balloon. The adhesive material is heated to above a melting point of the adhesive material. The adhesive material is cooled to below a melting point of the adhesive material to provide an adhesive bond that retains the stent to the catheter during vascular delivery, wherein the stent is released from the balloon following inflation and deflation of the balloon at a treatment site.

Abstract: The present invention provides a system for treating a vascular condition, including a catheter, a stent coupled to the catheter, a drug-polymer coating on the stent including a polymeric blend of a phenoxy polymer and a styrenic block copolymer, and a bioactive drug dispersed within the drug-polymer coating.

Abstract: A medical device for use within a body lumen that is made from a binary nickel-titanium alloy that remains in its austenitic phase throughout its operational range is disclosed. The medical device, such as an intraluminal stent, is made from superelastic nickel-titanium and may optionally be alloyed with a ternary element. By adding the ternary element and/or through heat treatment, it is possible to lower the phase transformation temperature between the austenitic phase and the martensitic phase of the nickel-titanium alloy. By lowering the phase transformation temperature, the martensite deformation temperature is likewise depressed. It is possible then to depress the martensite deformation temperature below body temperature such that when the device is used in a body lumen for medical treatment, the nickel-titanium device remains completely in the austenitic phase without appearance of stress-induced martensite even if the device is placed under stress.

Abstract: A radiopaque nitinol medical device such as a stent for use with or implantation in a body lumen is disclosed. The stent is made from a superelastic alloy such as nickel-titanium or nitinol, and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, or hafnium. The nitinol stent has improved radiopacity yet retains its superelastic and shape memory behavior and further maintains a thin strut/wall thickness for high flexibility. Another embodiment includes a balloon expandable stent made from a radiopaque and MRI compatible alloy such as nitinol and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, hafnium, osmium, zirconium, niobium, or molybdenum.

Abstract: A stent and a method of making it from a wire, which method includes winding the wire on a mandrel, heating to form a coiled spring, and reversing the winding direction of the coiled spring to form the reversed coiled spring stent. The stent so formed may be reheated over a special mandrel so as to partly relax the outer portion of some or all of the stent coils. The stent may be made up of two or more sections, with adjoining section wound in opposite senses. Such a stent may be deployed by winding the stent onto a catheter, immobilizing the two ends of the wire and one or more intermediate points, bringing the stent to the location where it is to be deployed, and releasing first the intermediate point or points and then the end points. The release of the wire may be accomplished by heating the thread immobilizing the wire so that the thread breaks and releases the wire.

Abstract: A prosthesis for insertion into a body passage is disclosed. The prosthesis includes a plastic or polymer base material which is compatible with living tissue and which possesses a memory of a predetermined configuration. The base material further has a glass transition temperature at which the prosthesis can be molded intravascularly from the predetermined configuration to a larger-radius implant configuration, which is sized and shaped to conform to an internal anatomy of the body passage to expand a narrow segment of or to occlude an opening of an out pouch of the body passage. The glass transition temperature is greater than a temperature of the body passage so that the prosthesis after being molded can be allowed to cool to the temperature of the body passage.

Abstract: The invention provides a method of manufacturing a system for treating a vascular condition. A catheter including an inflatable balloon is provided. A stent is positioned over the balloon. An adhesive material is applied between an inner surface of the stent and an outer surface of the balloon. The adhesive material is heated to above a melting point of the adhesive material. The adhesive material is cooled to below a melting point of the adhesive material to provide an adhesive bond that retains the stent to the catheter during vascular delivery, wherein the stent is released from the balloon following inflation and deflation of the balloon at a treatment site.

Abstract: An implantable expandable medical device in which selected regions of the device are in a martensite phase and selected regions are in an austenite phase. The martensitic regions exhibit pseudoplastic behavior in vivo and may be deformed without recovery under in vivo body conditions.

Abstract: A radiopaque nitinol medical device such as a stent for use with or implantation in a body lumen is disclosed. The stent is made from a superelastic alloy such as nickel-titanium or nitinol, and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, or hafnium. The added ternary element improves the radiopacity of the nitinol stent comparable to that of a stainless steel stent of the same size and strut pattern coated with a thin layer of gold. The nitinol stent has improved radiopacity yet retains its superelastic and shape memory behavior and further maintains a thin strut/wall thickness for high flexibility.

Abstract: In accordance with embodiments of the present invention, a method for preparing a shape memory alloy endoprosthesis, displaying strain induced martensite phenomenon, for delivery includes inserting a shape memory alloy endoprosthesis into a delivery device, inducing a first strain within a first region of the shape memory alloy endoprosthesis, inducing a second strain within a second region of the shape memory alloy endoprosthesis, and sterilizing the delivery device while maintaining the first strain and the second strain induced within the shape memory alloy endoprosthesis. In accordance with other embodiments of the present invention, an apparatus for delivering a shape memory alloy endoprosthesis includes an inner core having a first diameter, an outer body having a second diameter greater than the first diameter, and a calibrated endcap attached to the inner core.

Abstract: A radiopaque nitinol medical device such as a stent for use with or implantation in a body lumen is disclosed. The stent is made from a superelastic alloy such as nickel-titanium or nitinol, and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, or hafnium. The nitinol stent has improved radiopacity yet retains its superelastic and shape memory behavior and further maintains a thin strut/wall thickness for high flexibility. Another embodiment includes a balloon expandable stent made from a radiopaque and MRI compatible alloy such as nitinol and includes a ternary element selected from the group of chemical elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, hafnium, osmium, zirconium, niobium, or molybdenum.