Abstract: A vascular endoprosthesis (1) is disclosed which is capable of being arranged internally to the aortic arch (O), comprising: a tubular main body (2), to be housed in the internal lumen of the aortic arch (O); three tubular secondary bodies (3, 4, 5), originating from the main body (2) and to be housed in the right carotid artery (R), in the left carotid artery (L) and in the subclavian artery (S); and stent-type engagement means (10, 11, 13, 14, 15), intended to hold a longitudinal end portion (21, 22, 31, 41, 51) of the main and secondary bodies onto the internal wall of the respective vessel (FIG. 5).

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: A branch vessel suture stent system and method including a branch vessel suture stent having a stent body having a first end, a second end, and a central axis, the first end having a first periphery; and shape memory hooks disposed about the first periphery, each of the shape memory hooks being attached to the first periphery at an attachment point, the shape memory hooks being elongated in a stressed state and looped in a parent state, each of the shape memory hooks defining a loop plane in the parent state. The shape memory hooks are substantially parallel to the central axis in the stressed state, and the first periphery at the attachment point for each of the shape memory hooks is substantially orthogonal to the loop plane for each of the shape memory hooks in the parent state. The delivery system allows the main body of the branch device to expand while maintaining the hooks in an undeployed configuration using individual hypotubes.

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: A stent comprises one or more circumferential serpentine bands and having alternating peak portions and trough portions. The peak portions include shorter peak portions and longer peak portions. The longer peak portions are of a longitudinal extent greater than the shorter peak portions. The longer peak portions include first bent peak portions which extend in a first direction non-parallel to the longitudinal axis of the stent and second bent peak portions which extend in a second direction non-parallel to the longitudinal axis of the stent. Each first bent peak portion is circumferentially adjacent to one second bent peak portion which points toward the first bent peak portion and to one second bent peak portion which points away from the first bent peak portion. Adjacent first and second bent peak portions which point toward one another are separated one from the other by at least one shorter peak portion.

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: Normally, when stents are bent, inside the body of the stented patient, there is head-to-head collision between facing V-points on the inside of the bend. However, by alternating between two whole numbers the number of struts between successive connectors around the circumference of each of the stenting rings, the V-points are caused to veer circumferentially in opposite directions as they approach each other on the inside of the bend, so allowing them to pass by each other without collision, thereby allowing in the same stent both close packing of the ring stack, and an enhanced ability to tolerate severe bending, after placement in the body.

Abstract: An endoluminal prosthesis, comprising a tubular body, said tubular body developing along a longitudinal axis, said tubular body comprising a plurality of serpentines, which develop along a substantially circumpherential direction, each of said serpentines comprising arm portions of a preset width transversal to their main longitudinal extension, and bend portions joining two subsequent arms, at least one bridge, having a main longitudinal extension, connecting two adjacent serpentines, wherein the bends facing an adjacent serpentine are circumpherentially staggered relative to the opposite bends of the adjoining serpentine, both when the prosthesis is collapsed and when the prosthesis is expanded or partially expanded, wherein the at least one bridge connecting adjacent serpentines extends substantially straight, and wherein the at least one bridge has a width transversal to its main longitudinal direction of a greater value than the arm width.

Abstract: An expandable endovascular implant (10) of the stent type is described, which is suitable in particular for occlusion of a blood vessel (31). The implant comprises a circumferential tubular wall extending about a longitudinal axis and composed of a radially expandable, flexible lattice structure, said wall enclosing a cylindrical hollow space with a cross section, characterized in that the cylindrical hollow space defined by the wall is narrowed at least one location along its axis.

Abstract: Superelastic and/or shape memory nickel-titanium alloys having an increased fatigue life that is superior to known nickel-titanium alloys are disclosed. The nickel-titanium alloys have a minimum fatigue life that may be at least about 10 million strain cycles at a strain of at least about 0.75. The minimum fatigue life may be due, at least in part, to the nickel-titanium alloy having at least one of an oxygen concentration of less than about 200 ppm, a carbon concentration of less than about 200 ppm, the absence of oxide-based and/or carbide-based inclusions having a size greater than about 5 microns (?m), the presence of an R-phase, or combinations of the foregoing. Articles manufactured from such fatigue-resistant nickel-titanium alloys can be more durable because they are more resistant to repetitive strain and crack propagation.

Abstract: A stent assembly comprises a stent and a side branch flap. The stent has a substantially tubular body which defines a primary lumen and is comprised of a plurality of interconnected stent members. Adjacent stent members define a plurality of stent openings that extend through the body and which are in fluid communication with the primary lumen. At least one stent opening is a side branch opening. The side branch flap is a non-tubular body having a planar structure. A first region of the planar structure is overlappingly positioned across a portion of the side branch opening prior to deployment. A second region of the planar structure is engaged to a portion of the body of the stent immediately adjacent to the perimeter of the side branch opening. When the assembly is deployed the first region of the flap is displaced radially outward from the side branch opening.

Abstract: An intravascular stent especially suited for implanting in curved arterial portions or ostial regions. The stent can include an end region which is fabricated to have a greater radial strength than the remaining axial length of the stent. Such a stent is particularly suited for use in ostial regions, which require greater support near the end of the stent. The stent alternatively can include sections adjacent the end of the stent with greater bending flexibility than the remaining axial length of the stent. Such a stent is particularly suited for use in curved arteries. The stent can also be constructed with an end that has greater radial strength and sections adjacent the end with greater bending flexibility. Such a stent prevents flaring of the stent end during insertion.

Abstract: A stent for treating a region of a body lumen wherein at least two vessels form a junction includes a compressed state and an expanded state. In the expanded state, the stent is generally an ellipsoidal, spheroidal, or spherical shape. The stent is delivered to the junction in the compressed state disposed within a sleeve. Once at the junction, the sleeve is withdrawn proximally relative to the stent such that the stent is released from the sleeve and expands to the expanded state. A balloon may further expand the stent to appose the walls of the body lumen at the junction.

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: To provide a stent which holds various performances such as deliverability, prevention of restenosis, flexible shape conformability, and so on and is therefore adaptable not only to a bile duct but also to a blood vessel system such as a tortuous coronary artery substantially without causing restenosis. A stent with an autonomic function is made of a Ti—Ni based shape memory alloy and has a maximum expanding force at a center portion in its lengthwise direction.

Abstract: An intravascular device for minimally invasive deployment within a vessel includes a closed loop of flexible material configured to assume a first state in which the closed loop is folded on itself and straightened to allow delivery through a minimally invasive delivery system. When deployed, the loop assumes a second substantially ring-shaped state to become lodged against an inner wall of the vessel. The loop is preferably formed from a shape memory alloy preset to the second state and temporarily deformed to assume said first state during deployment.

Abstract: A medically implantable stent comprising at least one piezo-electric material may be active, such as by one or more of: delivering an anti-coagulant or other therapeutic effect to a patient in which it is implanted; powering itself; and/or sending an outbound electronic signal to a remote device. When a stent can send such an outbound signal, a physician may non-invasively ascertain the condition of the tissue near the stent.

Abstract: An endoprosthesis comprises a member capable of supporting a body passageway. The member has a surface region overlying a bulk region, and comprises a shape memory alloy and boron. The concentration of boron in the surface region is greater than the concentration of boron in the bulk region.

Abstract: A balloon or dilatation activated stent particularly for use in a body vessel for specific lesions, particularly in the region of the ostium of a vessel or a bifurcation featuring at least two different stent characteristics (20, 30) as needed for optimal stent treatment. The main portion is predominantly plastically deformable and at least one end portion is elastically deformable and opens to a diameter significantly larger than the diameter of the main portion thereby covering the area of a vessel bifurcation or the ostium and the adjacent vessel wall by conforming to it. The second stent is protruding axially from at least one end (proximal and/or distal) of the first stent.

Abstract: An implantable, radially distensible stent includes a plurality of helically wound elongate members. The members include an overlapping portion having a longitudinal extent, opposed and convexly rounded sides defining a width of the members and opposed luminal and exterior surfaces. The members include shape memory polymer. The side of one elongate member slidingly overlaps the side of an adjacent elongate member to form a self-supporting wall structure of a stent. The stent wall is self-supporting without other support structure incorporated into or abutting the elongate members. Further, the shape memory polymer may comprise a biodegradable or bioabsorbable elements.

Abstract: A stent comprises a tubular member having openings therein and having a plurality of interconnected members and one or more frangible restraining members. The frangible restraining members break upon partial expansion of the stent. Thereafter, the stent self-expands.

Abstract: Methods of selectively treating linear elastic materials to produce localized areas of superelasticity and/or shape-memory are disclosed. In an illustrative method, a linear elastic workpiece may be formed into a particular shape by cold-forming or other low-temperature process, and incorporated into a medical device such as an embolic protection filter, vena cava filter, stent or guidewire. A heat source may be used to apply thermal energy to selective areas of the workpiece, imparting superelasticity to the material.

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: Endolumenal prostheses that readily and extensively convert from a delivery configuration to a deployed configuration are disclosed. Endolumenal prostheses may be fabricated from one or more shape memory polymers, a high modulus elastomer, a polymer that is both elastomeric and exhibits shape memory behavior, a hydrogel, or some combination thereof. Polymers used to fabricate the prostheses are selectively synthesized to exhibit desired characteristics such as crystallinity, strain fixity rate, strain recovery rate, elasticity, tensile strength, mechanical strength, cross-linking density, extent physical cross-linking, extent of covalent cross-linking, extent of interpenetrating networks, rate of erosion, heat of fusion, crystallization temperature, and acidity during erosion. The endolumenal prostheses convert to the deployed configuration following delivery to a treatment site, upon exposure to an initiator either present within the body naturally or introduced into the body.

Abstract: A stent and method of its use, the stent in its expanded configuration, exhibiting varying outward radial force along its length. In use, the expanded stent is of a tapered configuration which provides greater force in vessel regions requiring greater force and less force in regions requiring less. In particular the stent is useful in the ostium regions and at areas of bifurcation in vessels. Varying force over the length of the stent is achieved by varying the number of elements, the density of elements, the thickness of the elements making up the stent body, and maintaining a substantially metal to artery ratio in the expanded stent over its length.

Abstract: Devices and methods are provided for reducing the lateral displacement of an endovascular device, e.g. a stent graft, within an aneurysm sac. A stabilization system comprising one or more stabilizing elements is inserted within the aneurysm space between an implanted device and the vessel wall. Filling this space prevents changes in curvature of the implanted endovascular device, and prevents longitudinal displacement, thereby providing for improved long-term stability and durability of endovascular repair.

Abstract: An implantable vascular prosthesis is provided for use in a wide range of applications wherein at least first and second helical sections having alternating directions of rotation are coupled to one another. The prosthesis is configured to conform to a vessel wall without substantially remodeling the vessel, and permits accurate deployment in a vessel without shifting or foreshortening.

Abstract: An endoluminal prosthesis, comprising a tubular body, said tubular body developing along a longitudinal axis, said tubular body comprising a plurality of serpentines, which develop along a substantially circumpherential direction, each of said serpentines comprising arm portions of a preset width transversal to their main longitudinal extension, and bend portions joining two subsequent arms, at least one bridge, having a main longitudinal extension, connecting two adjacent serpentines, wherein the bends facing an adjacent serpentine are circumpherentially staggered relative to the opposite bends of the adjoining serpentine, both when the prosthesis is collapsed and when the prosthesis is expanded or partially expanded, wherein the at least one bridge connecting adjacent serpentines extends substantially straight, and wherein the at least one bridge has a width transversal to its main longitudinal direction of a greater value than the arm width.

Abstract: A modular stent comprises at least one stent module including an intermediate segment consisting of one of either a closed-cell segment or a Z-segment and a pair of end segments connected to respective longitudinal ends of said intermediate segment, each end segment consisting of the other of said closed-cell segment or Z-segment, each closed-cell segment consisting solely of at least one annular closed-cell ring and each Z-segment consisting solely of at least one annular Z-ring. A method of manufacturing a stent form a small diameter tube includes laser-cutting the small diameter tube to define a plurality of longitudinally adjacent Z-rings, providing interconnector portions of said tube integrally joining facing aligned or offset Z-rings, expanding the small diameter tube, and removing predetermined interconnector portions from the expanded tube to provide the predetermined desired arrangement of interconnected closed-cell rings and Z-rings.

Abstract: A branch vessel in a human patient is located or mapped using in vivo tracked field sensors where in one variation the sensor positions can be located by determining the positions of the sensors relative to a plurality of magnetic field sources of known location. This approach is used, for example, in locating the opening in a renal artery and positioning the proximal end of the AAA stent-graft adjacent to the opening. In another example, the sensors are tracked along the inner wall of an aneurysm and the acquired sensor location data processed to map the contour of the aneurysm to size a prostheses for spanning the aneurysm. The portions of the vessel adjacent the aneurysm also can be mapped. In a further embodiment, an in vivo sensor is positioned in a deployed prosthesis to create a reference for a prosthetic member having a sensor to track to during cannulation of the deployed prosthesis with the prosthetic member.

Abstract: A medical implant, having a proximal and a distal end, that is preformed to assume a superimposed structure at an implantation site but can be made to take on a volume-reduced form making it possible to introduce it by means of a micro-catheter and a guide wire arranged at the proximal end, with the implant in its superimposed structure assuming the form of a longitudinally open tube and having a mesh structure of interconnected strings or filaments. The implant has a tapering structure at its proximal end where the strings or filaments converge at a connection point.

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: Methods and devices are provided for providing a protective framework for treating an aneurysm with embolic coils and preventing mitigation of the embolic coils from the aneurysm. A dynamically remodelable stent having a first and a second configuration is delivered into the blood vessel patient, such as a human or other animal, and positioned adjacent an ostium of an aneurysm while in the first, linear configuration. The dynamically remodelable stent may then be activated to assume a second, expanded configuration and thereby provide a protective framework spanning the neck of the aneurysm during and after delivery of embolic devices, such as embolic coils, to the aneurysm. The stent can be activated within the body of a patient in a minimally invasive or non-invasive manner such as by applying energy percutaneously or external to the patient's body. The energy may include, for example, acoustic energy, radio frequency energy, light energy and magnetic energy.

Abstract: An improved guiding member for use within a body lumen having a unique combination of superelastic characteristics. The superelastic alloy material has a composition consisting of about 30% to about 52% (atomic) titanium, and about 38% to 52% nickel and may have one or more elements selected from the group consisting of iron, cobalt, platinum, palladium, vanadium, copper, zirconium, hafnium and niobium. The alloy material is subjected to thermomechanical processing which includes a final cold working of about 10 to about 75% and then a heat treatment at a temperature between about 450° and about 600° C. and preferably about 475° to about 550° C. Before the heat treatment the cold worked alloy material is preferably subjected to mechanical straightening. The alloy material is preferably subjected to stresses equal to about 5 to about 50% of the room temperature ultimate yield stress of the material during the thermal treatment.

Abstract: A self-expandable shape memory alloy stent includes first and second wires made of super-elastic shape memory alloy. The first wire extends downwardly from the top to the bottom of the stent without interlocking with itself but extends upwardly from the bottom to the top of the stent while interlocking with itself to leave a multiplicity of rhombic spaces. Similarly, the second wire extends downwardly from the top to the bottom of the stent without interlocking with itself but extends upwardly from the bottom to the top of the stent while interlocking with itself, in such a manner as to divide the rhombic spaces formed by the first wire into four small rhombic spaces. The first wire and the second wire are woven with each other in such a manner that the second wire passes alternately below and above the first wire at intersection points.

Abstract: A catheter deliverable stent/graft especially designed to be used in a minimally invasive surgical procedure for treating a variety of vascular conditions such as aneurysms, stenotic lesions and saphenous vein grafts, comprises an innermost tubular structure and at least one further tubular member in coaxial arrangement. In one embodiment, the innermost tubular structure is of a length (L1) and is formed by braiding a relatively few strands of highly elastic metallic alloy. The pick and pitch of the braid are such as to provide relative large fenestrations in the tubular wall that permit blood flow through the wall and provide the primary radial support structure. A portion of the innermost tubular structure of a length L1 is surrounded by a further braided tubular structure having relatively many strands that substantially inhibit blood flow through the fenestrations of the innermost tubular structure.

Abstract: An improved guiding member for use within a body lumen having a unique combination of superelastic characteristics. The superelastic alloy material has a composition consisting of about 30% to about 52% (atomic) titanium, and about 38% to 52% nickel and may have one or more elements selected from the group consisting of iron, cobalt, platinum, palladium, vanadium, copper, zirconium, hafnium and niobium. The alloy material is subjected to thermomechanical processing which includes a final cold working of about 10 to about 75% and then a heat treatment at a temperature between about 450° and about 600° C. and preferably about 475° to about 550° C. Before the heat treatment the cold worked alloy material is preferably subjected to mechanical straightening. The alloy material is preferably subjected to stresses equal to about 5 to about 50% of the room temperature ultimate yield stress of the material during the thermal treatment.

Abstract: An aneurysm neck covering device which is particularly useful for sealing the neck of an aneurysm located in the vicinity of a bifurcated blood vessel. The neck covering device includes a self-expanding stent for supporting and retaining a self-expanding neck cover which seals the neck of the aneurysm.

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: The present invention provides a stent for delivering drugs to a vessel in a body, including a stent framework with a plurality of reservoirs formed therein, a drug polymer positioned in the reservoirs, and a polymer layer positioned on the drug polymer. The present invention also provides a method of manufacturing a drug-polymer stent and a method of treating a vascular condition using the drug-polymer stent.

Abstract: A medical device comprises a catheter having a catheter shaft and a balloon located at the distal end of the catheter shaft, and a bifurcated stent. The bifurcated stent comprises a trunk and at least two joined cylindrical parts extending from the trunk. A first part is capable of radially self-expanding and a second part is radially expandable only by means of a force applied thereto. At least a portion of the second part is disposed about the balloon prior to being radially expanded.

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 tubular prosthesis device for use within the body. The device includes, a metal filament material formed of metal outer member having an exposed outer surface and a core within the extended outer member formed of a different metal than the outer member. The core is secured within and substantially enclosed by the outer member. The device can be reduced to a small size for introduction into the body lumen and expandable to a sufficiently large size to engage the wall of the body lumen. Stents formed of composite wires are shown.

Abstract: A method for treatment of mitral annulus dilatation comprises reducing the circumference of the mitral valve annulus. The method further comprises inserting an elongate body into the coronary sinus in the vicinity of the posterior leaflet of the mitral valve, fixing the position of the elongate body relative to the coronary sinus, and changing the shape of the elongate body in order to remodel the mitral valve annulus.

Abstract: New tubular vascular implants (stents) that consist of biocompatible, thermoplastic material that have a shape memory and that contain at least one active ingredient are described. In addition, a process for their production and their use as vascular implants for prophylaxis of restenosis are described.

Abstract: A flexible covered stent having a stent covered on a first surface by a first layer of biocompatible material and on a second surface by both a second and third layer of biocompatible material, the first and second layers and the first and third layers of biocompatible material being bonded to one another through openings in a wall in the stent. The first layer of biocompatible material is longer than both the second and third layers of biocompatible material such that at least a portion of the second surface of the stent is not covered by either second or third layer, imparting flexibility to the stent.

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: 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: Medical devices may be made of shape-memory materials portions of which have been heat treated to exhibit spatial variations in the stiffness of the material. Devices including stents, vena cava filters and guidewires may be constructed from such materials. Devices may also be made from shape-memory materials which have been locally heat treated such that the superelasticity of the treated portion is destroyed while the remainder of the shape-memory material can transition between the martensitic and austenitic states.