# US 6,290,721 B1 · Tubular medical endoprostheses > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,290,721 B1 - Document ID: US6290721B1 - Status: Granted - Kind: B1 - Application number: 08/955,268 - Filed: 1997-10-21 - Granted: 2001-09-18 - Earliest claimed: 1992-03-31 - Assignees: Boston Scientific Corporation - Inventors: Kevin R. Heath - Web page: https://patentgrep.com/patent/US6290721B1 ## CPC - A61F 2/90: characterised by a net-like or mesh-like structure - A61B 90/39: {Markers, e.g. radio-opaque or breast lesions markers} - A61L 31/022: {Metals or alloys} - A61L 31/088: {Other specific inorganic materials not covered by A61L31/084 or A61L31/086} - A61L 31/18: Materials at least partially X-ray or laser opaque - A61M 25/0108: {using radio-opaque or ultrasound markers} - A61F 2210/0019: operated at only one temperature whilst inside or touching the human body, e.g. constrained in a non-operative shape during surgery, another temperature only occurring before the operation - A61F 2230/0006: circular - A61F 2230/0013: Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped - A61F 2240/001: Designing or manufacturing processes - A61F 2250/0098: radio-opaque, e.g. radio-opaque markers - A61M 2025/09166: {having radio-opaque features} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## 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. ## Claims ### Claim 1 A tubular prosthesis device for use within the body comprised at least in part of an elongated filament-form metal element adapted to be subjected to elastic deformation to enable the device to be forced into a characteristic deformed configuration during a stage of use and to elastically self-recover from said deformation when deformation forces are relieved, said filament-form metal element comprised of a core of a first metal of a first selected thickness and an intimately surrounding sheath of a second selected metal of a second thickness, said first metal being of a substantially higher radiopacity than that of said second metal, said second metal being substantially more elastic than said first metal, the metals in said filament-form metal element serving to enhance the radiopacity of said filament-form metal element to provide improved fluoroscopic or x-ray visualization of said filament-form metal element in said body while imparting sufficient elasticity to enable the filament-form metal element to elastically self-recover from said characteristic deformed configuration. ### Claim 2 (depends on 1) The device of claim 1, wherein said filament-form metal element is the product produced by draw-forming. ### Claim 3 (depends on 1) The device of claim 1, wherein said second metal is nitinol. ### Claim 4 (depends on 3) The device of claim 3, wherein said high density metal is tantalum. ### Claim 5 (depends on 1) The device of claim 1, wherein said tubular prosthetic device is formed into said tubular shape by knitting into loosely interlocked loops of said filament-form metal element. ### Claim 6 (depends on 1) The device of claim 1, wherein the transverse cross-sectional dimension of said filament-form metal element is about no greater than 0.015 inch. ### Claim 7 (depends on 1) The device of claim 1, wherein said transverse cross-sectional dimension of said filament-form metal is about 0.0045 to about 0.006 inch and said core has a transverse cross-sectional dimension of about 0.0014 to about 0.00195 inch. ### Claim 8 (depends on 1) The device of claim 1, wherein said core has a density of about at least 9.9 g/cc. ### Claim 9 (depends on 8) The device of claim 8, wherein said core is selected from the group consisting of tungsten, tantalum, rhenium, iridium, silver, gold, bismuth and platinum. ### Claim 10 (depends on 1) The device of claim 1, wherein said outer member is selected from superelastic alloys and precursors of superelastic alloys. ### Claim 11 (depends on 10) The device of claim 10, wherein said outer member is nitinol. ### Claim 12 (depends on 11) The device of claim 11, wherein said core is tantalum. ### Claim 13 (depends on 1) The device of claim 1, wherein a transverse cross-sectional dimension of said core is about 1 to 40% of a transverse cross-sectional dimension of said filament-form metal element. ### Claim 14 (depends on 13) The device of claim 13, wherein said core is about 25 to 40% of a transverse cross-sectional dimension of said filament-form metal element. ### Claim 15 (depends on 13) The device of claim 13, wherein said core is about 33% of a transverse cross-sectional dimension of said filament-form metal element. ### Claim 16 (depends on 1) The device of claim 1, wherein said core has a modulus of elasticity of about no greater than 500 GPa. ### Claim 17 (depends on 1) The device of claim 1, wherein said core has a modulus of elasticity of about no greater than 200 GPa. ### Claim 18 (depends on 1) The device of claim 1, wherein said filament-form metal element has a transverse cross-sectional dimension of less than about 0.0075 inch. ### Claim 19 (depends on 1) The device of claim 1, wherein said filament-form metal element has a transverse cross-sectional dimension of about 0.0045 inch to about 0.006 inch. ### Claim 20 (depends on 1) The device of claim 1, wherein said stent device has a diameter of about 4 mm to about 12 mm. ### Claim 21 (depends on 1) The device of claim 1, wherein said stent device has a length of about 2 cm to about 8 cm. ### Claim 22 (depends on 1) The device of claim 1, wherein said filament-form metal element is in an overlapping pattern. ### Claim 23 (depends on 1) The device of claim 1, wherein said stent device is a weave of said filament-form metal element. ### Claim 24 (depends on 1, 18, 19, 20, 21, 22, 23) The device of claim 1 or 18-23, wherein said first metal is tantalum. ### Claim 25 A tubular prosthesis for use within the body comprised at least in part of an elongated filament-form metal element, said filament-form metal element being arranged in an overlapping pattern defining a tube and adapted to be subjected to elastic deformation to enable the device to be forced into a characteristic deformed configuration during a stage of use and to elastically self-recover from said deformation when deformation forces are relieved, said filament-form metal element having transverse cross-sectional dimension of about 0.0075 inch or less and being comprised of a core of a first metal of a first selected thickness and an intimately surrounding sheath of a second selected metal of a second thickness, said first metal being tantalum and having a substantially higher density and demonstrating characteristically substantially higher radiopacity than that of said second metal, said second metal being substantially more elastic than said first metal, the combined effect of said first and second metals in said filament-form metal element to provide improved fluoroscopic or x-ray visualization of said filament-form metal element in said body while imparting sufficient elasticity to enable the filament-form metal element to elastically self-recover from said characteristic deformed configuration. ### Claim 26 An implantable tubular medical stent, comprising: a metal wire composed of multiple metal layers, including a first layer formed of a first metal and a second layer formed of a second metal, the first metal having a greater density than the second metal and the first layer being disposed inwardly of the second layer. ### Claim 27 (depends on 26) The implantable tubular stent of claim 26, wherein the wire is formed by draw-forming. ### Claim 28 (depends on 26) The implantable tubular stent of claim 26, wherein the second metal is nitinol. ### Claim 29 (depends on 28) The implantable tubular stent of claim 28, wherein the first metal is tantalum. ### Claim 30 (depends on 26) The implantable tubular stent of claim 26, wherein the stent is formed by knitting, weaving or crocheting the wire. ### Claim 31 (depends on 26) The implantable tubular stent of claim 26, wherein the wire has an overall diameter of no greater than about 0.015 inch. ### Claim 32 (depends on 26) The implantable tubular stent of claim 26, wherein the first metal has a density of at least about 9.9 g/cc. ### Claim 33 (depends on 26) The implantable tubular stent of claim 26, wherein the first metal is selected from the group consisting of stainless steel, tantalum, rhenium, iridium, silver, gold, bismuth and platinum. ### Claim 34 (depends on 26) The implantable tubular stent of claim 26, wherein the second metal is selected from the group consisting of stainless steel, superelastic alloys and precursors of superelastic alloys. ### Claim 35 (depends on 26) The implantable tubular stent of claim 26, wherein the second metal is nitinol. ### Claim 36 (depends on 35) The implantable tubular stent of claim 35, wherein the first metal is tantalum. ### Claim 37 (depends on 26) The implantable tubular stent of claim 26, wherein the core has a diameter of about 1 to 40% of an overall diameter of the wire. ### Claim 38 (depends on 37) The implantable tubular stent of claim 37, wherein the wire has an overall diameter of about 0.0045 to 0.006 inch and the core has a diameter of about 0.0014 to 0.00195 inch. ### Claim 39 (depends on 37) The implantable tubular stent of claim 37, wherein the core has a diameter of about 25% to 40% of the overall diameter of the wire. ### Claim 40 (depends on 39) The implantable tubular stent of claim 39, wherein the core is about 33% of the overall diameter of the wire. ### Claim 41 (depends on 26) The implantable tubular stent of claim 26, wherein the first metal has a modulus of elasticity of no greater than about 500 GPa. ### Claim 42 (depends on 41) The implantable tubular stent of claim 41, wherein the first metal has a modulus of elasticity of no greater than about 200 GPa. ### Claim 43 (depends on 26) The implantable tubular stent of claim 26, wherein the stent has a length in the range of about 2-8 cm. ### Claim 44 (depends on 43) The implantable tubular stent of claim 43, wherein the stent has a diameter in the range of about 4-12 mm. ### Claim 45 An implantable tubular medical stent, comprising: a metal wire composed of multiple metal layers, including a first layer formed of a first metal and a second layer formed of a second metal, the first metal having a greater density than the second metal and being selected from the group consisting of tantalum, platinum, tungsten and iridium, the first layer being disposed inwardly of the second layer. ### Claim 46 (depends on 45) The implantable tubular stent of claim 45, wherein the first metal is tantalum. ### Claim 47 (depends on 45) The implantable tubular stent of claim 45, wherein the core has a diameter greater than about 1% of an overall diameter of the wire. ### Claim 48 (depends on 47) The implantable tubular stent of claim 47, wherein the core has a diameter of about 50% or less of the overall diameter of the wire. ### Claim 49 (depends on 45) The implantable tubular stent of claim 45, wherein the second metal is selected from the group consisting of stainless steel, superelastic alloys and precursors of superelastic alloys. ### Claim 50 (depends on 45) The implantable tubular stent of claim 45, wherein the stent has a length of about 2-8 cm and a diameter in the range of about 4-12 mm. ### Claim 51 (depends on 45) The implantable tubular stent of claim 45, where in the wire has a diameter of about 0.0075 inch or less. ### Claim 52 (depends on 46) The implantable tubular stent of claim 46, where in the wire has a diameter of about 0.0075 inch or less. ### Claim 53 (depends on 47) The implantable tubular stent of claim 47, where in the wire has a diameter of about 0.0075 inch or less. ### Claim 54 (depends on 48) The implantable tubular stent of claim 48, where in the wire has a diameter of about 0.0075 inch or less. ### Claim 55 (depends on 49) The implantable tubular stent of claim 49, where in the wire has a diameter of about 0.0075 inch or less.