WO2014162903A1 - Galvanic corrosion stent - Google Patents

Galvanic corrosion stent Download PDF

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Publication number
WO2014162903A1
WO2014162903A1 PCT/JP2014/057906 JP2014057906W WO2014162903A1 WO 2014162903 A1 WO2014162903 A1 WO 2014162903A1 JP 2014057906 W JP2014057906 W JP 2014057906W WO 2014162903 A1 WO2014162903 A1 WO 2014162903A1
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Prior art keywords
metal material
stent
galvanic corrosion
connecting portion
galvanic
Prior art date
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PCT/JP2014/057906
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French (fr)
Japanese (ja)
Inventor
猛士 馬場
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テルモ株式会社
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Publication of WO2014162903A1 publication Critical patent/WO2014162903A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61L31/00—Materials for other surgical articles, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices
    • A61L31/02—Inorganic materials
    • A61L31/022—Metals or alloys
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
    • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
    • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
    • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
    • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
    • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
    • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
    • A61F2002/91533—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other characterised by the phase between adjacent bands
    • A61F2002/91541—Adjacent bands are arranged out of phase
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
    • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
    • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
    • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
    • A61F2002/9155—Adjacent bands being connected to each other
    • A61F2002/91558—Adjacent bands being connected to each other connected peak to peak
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
    • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
    • A61F2/91—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
    • A61F2/915—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes with bands having a meander structure, adjacent bands being connected to each other
    • A61F2002/9155—Adjacent bands being connected to each other
    • A61F2002/91566—Adjacent bands being connected to each other connected trough to trough
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2210/00—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2210/0004—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof bioabsorbable
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2250/0014—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
    • A61F2250/0043—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis differing in electric properties, e.g. in electrical conductivity, in galvanic properties
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2250/0058—Additional features; Implant or prostheses properties not otherwise provided for
    • A61F2250/0071—Additional features; Implant or prostheses properties not otherwise provided for breakable or frangible
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • 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
    • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2250/0058—Additional features; Implant or prostheses properties not otherwise provided for
    • A61F2250/0096—Markers and sensors for detecting a position or changes of a position of an implant, e.g. RF sensors, ultrasound markers
    • A61F2250/0098—Markers and sensors for detecting a position or changes of a position of an implant, e.g. RF sensors, ultrasound markers radio-opaque, e.g. radio-opaque markers

Definitions

  • the present invention relates to a stent, particularly a galvanic corrosion stent in which a connecting portion is cut by galvanic corrosion after being placed in a living body.
  • ischemic heart diseases such as angina pectoris and myocardial infarction are less likely to invade patients, such as percutaneous transluminal coronary angioplasty (PTCA) for stenosis of coronary arteries.
  • PTCA percutaneous transluminal coronary angioplasty
  • Hematologic diseases and the like are treated by percutaneous transluminal angioplasty (PTA) or the like for the stenosis of these arteries.
  • PTA percutaneous transluminal angioplasty
  • Each of these treatment methods is a technique for securing and resuming blood flow by dilating a blood vessel that has been narrowed or occluded by using a catheter equipped with a balloon folded at the tip.
  • the present invention has been made in view of such circumstances, and its purpose is to generate a sufficient radial force in the initial stage after expansion, but its rigid characteristics after a certain period of time has elapsed after expansion. It is an object of the present invention to provide a stent capable of relieving unnecessary stress on a living body lumen such as a blood vessel due to the above.
  • a galvanic erosion stent that is composed of linear components and is in close contact with a living body lumen by being deformed during an indwelling operation in a living body, and the stent is annularly formed by the linear components.
  • a plurality of bodies are arranged in the axial direction, and adjacent annular bodies are connected by a connecting portion, and the annular body is formed of a first metal material, and at least a part of the connecting portion is The above-mentioned problem is solved by providing a galvanic corrosion stent that is formed of a second metal material that is more noble than the first metal material, is placed in a living body, and then the connection portion is cut by galvanic corrosion. As a result, the present invention has been completed.
  • a stent that generates sufficient radial force in the initial stage after expansion, but can release extra stress on the living body lumen after a certain time has elapsed after expansion.
  • FIG. 2 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 1;
  • FIG. 4 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 2.
  • FIG. 6 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 3; It is a figure which shows the apparatus for measuring a galvanic current. It is a figure which shows the measurement result of the galvanic current in the reference example 2.
  • X to Y indicating a range means “X or more and Y or less”, “weight” and “mass”, “weight%” and “mass%”, “part by weight” and “weight part”. “Part by mass” is treated as a synonym. Unless otherwise specified, operations and physical properties are measured under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.
  • each metal has its own potential.
  • galvanic a potential difference between a base metal (a metal with a high ionization tendency) and a noble metal (a metal with a low ionization tendency).
  • Potential occurs to form a battery (local battery, galvanic battery), current flows (local current), and corrosion occurs.
  • galvanic corrosion sometimes referred to as intermetallic corrosion or local battery corrosion.
  • the galvanic corrosion stent of the present invention a plurality of annular bodies formed in an annular shape by linear components are arranged in the axial direction and adjacent annular bodies are connected by a connecting portion.
  • the specific period of the “certain period” in the present specification is preferably about 1 to several months, for example, assuming 1 to 6 months, 2 to 5 months, or about 3 to 4 months. ing. It may be cut over a longer period, but it may be unpreferable if it is only 1 year or 2 years or more because excessive stress on the blood vessel continues more than necessary. Needless to say, the above period is general and may not always be the above depending on the severity and age of the patient.
  • the stent of the present invention includes a first metal material and a second metal material in order to generate this galvanic potential. More specifically, a plurality of annular bodies formed by annularly forming linear components formed of the first metal material are arranged in the axial direction, and the adjacent annular bodies are the first metal material. It is connected by a connecting portion formed to contain a noble second metal material. Then, when a difference in natural immersion potential exists between the first metal material and the second metal material, local current is generated, galvanic corrosion occurs, and the connection portion can be cut in the living body. . The greater the potential difference, the greater the local current that flows and the more corrosion is promoted.
  • the difference in natural immersion potential at this time is not particularly limited, but a difference in natural immersion potential that is cut after the elapse of the predetermined period is preferable.
  • natural immersion between the first metal material and the second metal material is preferable.
  • the difference in potential is more than 200 mV and preferably 1000 mV or less, more preferably about 210 to 800 mV, more preferably about 210 to 500 mV, still more preferably about 210 to 300 mV, and about 210 to 250 mV. Is particularly preferred. If it is 200 mV or less, current may hardly flow and galvanic corrosion may not easily occur. If it exceeds 1000 mV, corrosion may progress too quickly, preventing remodeling of blood vessels.
  • the “natural immersion potential” is measured by the method described in JIS T0302: 2000, and specifically, is a value (mV) measured by the following method. That is, first, the sample (first metal material and second metal material) is cut into appropriate sizes. In order to remove the influence at the time of cutting, the sample is polished under running water using water-resistant abrasive paper. At this time, the abrasive paper starts from the coarse one (No. 150) and finally uses up to No. 600. After polishing, the sample is ultrasonically cleaned in distilled water for 5 minutes. After cleaning, connect the conductor to the sample.
  • mV measured by the following method. That is, first, the sample (first metal material and second metal material) is cut into appropriate sizes. In order to remove the influence at the time of cutting, the sample is polished under running water using water-resistant abrasive paper. At this time, the abrasive paper starts from the coarse one (No. 150) and finally uses up to No. 600. After polishing, the sample is ultrasonically cleaned
  • a high purity nitrogen gas is bubbled through the PBS solution for 30 minutes or longer. Thereafter, the sample prepared above is immersed in a PBS solution.
  • the potential generated in the sample is measured with an electrometer (trade name: HE-104, manufactured by Hokuto Denko Co., Ltd.).
  • HE-104 manufactured by Hokuto Denko Co., Ltd.
  • a measurement is performed in the state immersed at 37 degreeC for 1 hour, and let the value after 1 hour be a natural immersion potential (mV).
  • the galvanic current in this specification is a value when a saturated calomel electrode (SCE) is used as a reference electrode.
  • SCE saturated calomel electrode
  • the thickness of the galvanic corrosion stent (annular body, connecting portion) of the present invention is not particularly limited as long as it has a radial force necessary to prevent remodeling of blood vessels and does not obstruct blood flow.
  • the range of 1 to 1000 ⁇ m is preferable, and the range of 50 to 300 ⁇ m is more preferable.
  • the galvanic erosion stent of the present invention is similar to a conventionally used stent in that a balloon-expandable stent (balloon-expandable stent) or a self-expandable stent (self-expandable stent) (self Any of expandable stents may be used.
  • the shape of the galvanic erosion stent of the present invention is not particularly limited, but it is necessary to have sufficient strength to be stably placed in a biological lumen such as a blood vessel.
  • the present invention since the present invention includes the second metal material composed of the metal material as the connecting portion, the joint strength with the first metal material also composed of the metal material can be designed sufficiently high. It can be stably placed in a living body lumen such as a blood vessel.
  • a biodegradable polymer for example, polylactic acid
  • polylactic acid is poor in ductility and may break before completion of placement in the body lumen.
  • the second metal material which is a metal material
  • the material constituting the connecting portion since the second metal material, which is a metal material, is included as the material constituting the connecting portion, the possibility of breaking before completion of placement in the living body lumen can be reduced. it can.
  • the thing which formed the fiber by knitting a fiber, the thing which provided the opening part in the tubular body, etc. are mentioned, for example.
  • FIG. 1 As shown in FIG. 1, in the stent 1, a plurality of wave-like annular bodies formed in an annular shape by the linear component 2 are arranged in the axial direction, and adjacent wave-like annular bodies are connected by a connecting portion C. It is a cylindrical body having an end portion opened and extending in the longitudinal direction between the both end portions.
  • the annular body is a wave-like annular body, a large diameter expansion rate is obtained, and it has an effect of being able to cope with the overexpansion often required in actual use.
  • the adjacent wavy annular bodies are connected by a connecting portion.
  • the side surface of the cylindrical body (stent) has a large number of notches communicating with the outer side surface and the inner side surface, and has a structure that can expand and contract in the radial direction of the cylindrical body by deforming the notch portions. . And if it is detained in living body lumens, such as a blood vessel, the shape will be maintained.
  • the stent 1 has a substantially rhombic element A with a notch formed inside as a basic unit.
  • the substantially rhombic element A includes two adjacent linear constituent elements 2; and a first connecting part C1 that connects the linear elements 2 to each other and has a relatively short connecting part C.
  • the substantially diamond-shaped element A is continuously arranged and coupled in the minor axis direction to form an annular unit B formed in an annular shape. That is, the annular unit B includes two adjacent wave-like annular bodies; and a first connecting portion C1 that connects the wave-like annular bodies.
  • a plurality of annular units B are arranged in the axial direction, and each adjacent annular unit B is further connected by a second connecting part C2, which is a connecting part C having a relatively long length. Thereby, each adjacent annular unit B is continuously arranged in the axial direction in a state in which a part thereof is coupled to each other.
  • the stent 1 has a cylindrical body that is open at both ends and extends between the ends in the longitudinal direction. And the side surface of the stent 1 has a substantially rhombus notch (substantially rhombus element A), and the notch is deformed so that the stent 1 can expand and contract in the radial direction.
  • a plurality of annular bodies (waved annular bodies) formed in an annular shape by the linear component 2 are arranged in the axial direction, and adjacent annular bodies are connected to the connecting portion C (first connecting portion C1, The second connecting portion C2) is connected, the annular body is formed of the first metal material, and at least a part of the connecting portion C (first connecting portion C1, second connecting portion C2) is formed.
  • the second metal material is nobler than the first metal material.
  • the connecting portion C (the first connecting portion C1 and the second connecting portion C2) is formed of the second metal material, the first metal material and the second metal material
  • a potential difference galvanic potential
  • current flows local current
  • corrosion occurs, and after a certain period, the connecting portion is disconnected, thereby releasing extra stress on the blood vessel due to rigid characteristics.
  • FIG. 2 is a partial enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 1 which is a preferred embodiment.
  • the central portion of the first connecting portion C ⁇ b> 1 is formed of the second metal material 5.
  • parts other than the center part of the 1st connection part C1 are formed of the 1st metal material 4 so that the 2nd metal material 5 may be interposed. That is, the 2nd metal material 5 is provided so that the 1st connection part C1 currently formed with the 1st metal material 4 may be parted.
  • a potential difference (galvanic potential) is generated between the first metal material 4 constituting the first connection portion C1 and the second metal material 5 similarly constituting the first connection portion C1.
  • Current flows local current
  • crevice corrosion occurs, the connection is cut after a certain period of time, and extra stress on the blood vessels due to rigid characteristics is released.
  • the second metal material has a higher specific gravity than the first metal material and has a high radiopacity
  • such a second metal material is provided so that the X-ray fluoroscopy can be performed.
  • a radiopaque metallic material may be specially installed as a marker at the end of the stent so that the position of the stent can be confirmed well under fluoroscopy.
  • the second metal material is made of galvanic corrosion by using a metal having a higher specific gravity and higher radiopacity than the first metal material.
  • the effect of excellent visibility of the stent is provided without providing a separate marker.
  • the second metal material since the second metal material is provided in the entire connecting portion constituting the stent, the second metal material can be safely placed in the living body lumen. In other words, the superior radiopacity during placement makes the position of the stent clear and facilitates surgery. However, in this invention, it does not prevent providing a separate marker in a stent main body (base material) further.
  • FIG. 3 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to another preferred embodiment, Embodiment 2.
  • FIG. 3 in the stent of the present embodiment, both end portions of the first connecting portion C ⁇ b> 1 are formed of the second metal material 5. Then, portions other than both end portions of the first connecting portion C ⁇ b> 1 are formed of the first metal material 4. Also in the present embodiment, a potential difference (galvanic potential) is generated between the first metal material 4 constituting the first connection portion C1 and the second metal material 5 similarly constituting the first connection portion C1.
  • a second metal material may be further provided in the central portion in addition to the both end portions of the first connecting portion C1, or a second metal material may be further provided. It may be done. However, from the viewpoint of manufacturing, it is preferable that the number of places where the second metal material is provided is up to five in one connecting portion. Thus, the stress release time can be easily adjusted by the number of installed second metal materials, the width, and the like.
  • FIG. 4 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 3, which is still another preferred embodiment.
  • all the first connecting portions C ⁇ b> 1 are made of the second metal material 5.
  • a potential difference galvanic potential between the first metal material 4 constituting the corrugated annular body (linear component 2) and the second metal material 5 constituting the first connecting portion C1.
  • current flows local current
  • crevice corrosion occurs
  • the connection portion is cut after a certain period of time, and extra stress on the blood vessel due to rigid characteristics is released.
  • the second metal material has a higher specific gravity than the first metal material and has a high radiopacity
  • the position of the stent can be confirmed well under fluoroscopy.
  • the visibility is further improved from the viewpoint that the entire first connecting portion C1 is formed of the second metal material 5.
  • it does not prevent providing a separate marker in a stent main body (base material) further.
  • there is an effect that the production of the stent is easy.
  • the form of the second metal material 5 in each first connection portion C1 has been described.
  • the second metal material 5 that is noble than the first metal material 4 can be applied to body fluids such as blood.
  • the corrosion rate can be adjusted by changing the surface area in contact (that is, the exposed surface area), and the time required for approximate cutting can also be adjusted.
  • the surface area is preferably obtained by multiplying the length of each joint interface portion of the first metal material 4 and the second metal material 5 exposed on the surface by about 0.05 to 20, and 0.1 to 10 A product multiplied by a degree is more preferable.
  • the surface area is the total when a portion composed of a plurality of second metal materials 5 is included in one connecting portion as in the second embodiment.
  • the length of each bonding interface portion includes a portion (bonding interface portion) partially alloyed at the interface between the first metal material 4 and the second metal material 5. means.
  • the surface area and the like can be appropriately adjusted according to the types of the first metal material and the second metal material, the size of the entire stent, etc., and values that deviate from the above range are selected. Of course it does not matter.
  • the form in which at least a part of the first connecting part C1 is formed of the second metal material has been described.
  • the second metal is also used in at least a part of the second connecting part C2.
  • it may be formed of a material, or may be either the first connecting part C1 or the second connecting part C2.
  • the description has been given focusing on only one connecting portion (the first connecting portion C1).
  • the second metal material is included in all the connecting portions included in one stent. There is a part consisting of five.
  • the radial force is significantly increased by the presence of the portion made of the second metal material 5 in 20 to 90%, or 30 to 80% of the total number of connecting portions in one stent. Reduces and releases extra stress on blood vessels due to rigid characteristics.
  • first metal material metals similar to those used as stents in the normal medical field can be used.
  • stainless steel, cobalt alloy, nickel-titanium alloy (Ni-Ti alloy) examples include tantalum, tantalum alloys, molybdenum, and molybdenum alloys.
  • cobalt-based alloy for example, Co—Cr-based alloy
  • nickel-titanium-based alloy Ni—Ti-based alloy
  • stainless steel that can be used in the normal medical field can be used in the same manner, and examples thereof include SS304, SS316L, SS420J2, SS630, and the like.
  • SS316L composition: carbon 0.035% by weight or less, phosphorus 0.04% by weight or less, sulfur 0.03% by weight or less, manganese 2.00% by weight or less, from the viewpoint of use in vivo, Silicon (0.75% by weight or less), chromium (16.00 to 18.00% by weight), nickel (12.00 to 15.00% by weight), molybdenum (2.00 to 3.00% by weight, balance iron) is preferable.
  • cobalt-based alloys that can be used in the normal medical field can be used in the same manner.
  • cobalt-chromium alloy such as L605, cobalt-nickel-chromium alloy, MP35N, etc.
  • cobalt-nickel-chromium-molybdenum alloy and cobalt-chromium-molybdenum alloy.
  • L605 composition: chrome 19.00 to 21.00% by weight, nickel 9.00 to 11.00% by weight, tungsten 14.00 to 16.00 from the viewpoint of strength and use in vivo. Wt%, iron max.
  • nickel-titanium-based alloys that can be generally used in the medical field can be used in the same manner.
  • examples thereof include a nickel-titanium alloy and a nickel-titanium-copper alloy obtained by adding copper to a nickel-titanium alloy.
  • nickel-titanium alloy (Nitinol) containing about 50 wt% to about 60 wt% nickel and the balance being titanium is preferable from the viewpoint of in-vivo use results and superelastic characteristics.
  • the second metal material is a noble metal than the first metal material and forms at least a part of the connecting portion. Similar to the first metal material, the second metal material can be the same metal as that usually used as a stent in the medical field. Specifically, gold, platinum, silver, palladium, and the like are mainly used. Any one of the alloys as the components is preferable, and in particular, any of gold, platinum, and an alloy containing them as the main component is preferable. In particular, since gold and platinum have high ductility, there is little risk of breakage before completion of indwelling. Further, due to its flexibility (low elasticity, high ductility), it has an effect of flexibly following the indwelling blood vessel shape and exhibiting excellent conformability. In the present specification, “main component” means a component having the largest mass% of all components.
  • the specific gravity of the second metal material is preferably 10 g / cm 3 or more, more preferably 12 g / cm 3 or more. There are no particular limitations on the upper limit, e.g., 23 g / cm 3 or less, or at 22 g / cm 3 or less.
  • the second metal material may be selected to be a noble metal than the first metal material.
  • the second metal material listed above is used. Two different kinds of metal materials are selected from the metal materials, and a relatively base metal material is used as the first metal material, and a noble metal material is used as the second metal material. Good.
  • a metal material having a relatively high specific gravity is used as a linear component forming the annular body, it may be hard and brittle. In that respect, the metal materials listed in the first metal material are not suitable. It is preferably used as a linear component forming an annular body.
  • the structure of the stent in the present invention is not limited to the form shown in FIG. 1, and a plurality of annular bodies formed annularly by linear components are arranged in the axial direction and adjacent annular bodies are connected. What is connected by the part should just be.
  • the cross-sectional shape of the wire (that is, linear component) which comprises a stent also includes a rectangle, a circle, an ellipse, other polygons, etc., other shapes may be sufficient.
  • the size of the stent described above is not particularly limited, and may be appropriately selected according to the application location.
  • the outer diameter of the stent before expansion (when attached to the balloon) is preferably about 0.3 to 5 mm, more preferably about 0.4 to 4.5 mm, and particularly preferably about 0.5 to 1.6 mm.
  • the length of the stent is not particularly limited and can be appropriately selected depending on the disease to be treated. For example, the length of the stent is preferably about 5 to 100 mm, more preferably about 6 to 50 mm.
  • the length of the stent is preferably about 1.5 to 4 mm, and more preferably about 2 to 3 mm.
  • the stent of the present invention can be produced by appropriately referring to or combining a known solid-phase joining method with a stent member made of the first metal material and a stent member made of the second metal material.
  • Known solid phase bonding methods include (1) pressure welding (2) diffusion bonding (3) friction welding (friction welding) (4) ultrasonic welding and the like.
  • a desired portion of the stent member made of the first metal material and the stent member made of the second metal material are solid-phase bonded to produce a bonded body (rod). .
  • the rod thus produced is cut out at the center to form a pipe. After that, alignment is performed so that the portion formed of the second metal material enters the connecting portion, and it is cut into a stent pattern by laser processing, and further, chemical polishing and electrolytic polishing can be performed to produce a stent. .
  • SS316L which is a metal constituting a commercially available stent (Nobori (registered trademark), manufactured by Terumo Corporation), L605 (Co—Cr alloy) which is a metal which constitutes a commercially available stent (Kaname (trademark), manufactured by Terumo Corporation)
  • the natural immersion potential (mV) was measured for gold and gold.
  • Table 1 The results are shown in Table 1 below. In this case, SS316L and L605 correspond to the first metal material, and gold corresponds to the second metal material. The results are shown in Table 1.
  • the galvanic current was measured by the following method using the apparatus of FIG. The results are shown in FIG. That is, the sample (gold) that is the second metal material was cut into an appropriate size (2 cm ⁇ 2 cm). After cutting, the sample was polished under running water using water-resistant abrasive paper. At this time, the abrasive paper started from the coarser one (No. 150) and finally used up to No. 600. After polishing, the sample was ultrasonically cleaned in distilled water for 5 minutes. After washing, the lead wire was connected to the sample by a clip. Next, the sample was covered with a sealing agent including the connecting portion with the conductor so that only 1 cm 2 was exposed. This was used as a sample electrode (electrode S2).
  • PBS solution composition: 8.0 g / L NaCl, 0.2 g / L KCl, 1.15 g / L Na 2 HPO 4 , 0.2 g / L KH 2 PO 4 , pH 7.2 to 7.6
  • the cell D was placed in a thermostatic bath (not shown), and the temperature of the PBS solution was maintained at 37 ° C. High purity nitrogen gas was bubbled into the PBS solution for 30 minutes or more. Thereafter, the electrodes S1 and S2 prepared above were immersed in a PBS solution. The current flowing between the counter electrode (electrode S1) and the sample electrode (electrode S2) was measured with a non-resistance ammeter (“I” in FIG. 5). The measurement temperature at this time was adjusted to 37 ° C.
  • the L605 pipe with a diameter (outer diameter) of 2 mm, a length of 0.9 mm, and a wall thickness of 80 ⁇ m, and an Au pipe with a diameter (outer diameter) of 2 mm, a length of 0.1 mm, and a wall thickness of 80 ⁇ m are made of ceramic so that the central axes are aligned.

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Abstract

[Problem] To provide a stent that can produce sufficient radial force in the initial period following dilation, while releasing unnecessary stress on a bodily lumen following dilation after a fixed time period has passed. [Solution] This galvanic corrosion stent is constituted by linear constituent components and is designed to closely adhere to a bodily lumen through deformation during an indwelling procedure in the body, wherein the galvanic corrosion stent has a plurality of annular elements formed to ring shape by the linear constituent components and arrayed in an axial direction, adjacent annular elements being linked by linking parts. The annular elements are formed of a first metal material, and the linking parts are formed at least in part of a second metal material more electropositive than the first metal material. Once the stent is indwelling in the body, the linking parts are severed through galvanic corrosion.

Description

ガルバニック腐食ステントGalvanic corrosion stent
　本発明は、ステント、特に生体内に留置された後、ガルバニック腐食によって連結部が切断される、ガルバニック腐食ステントに関する。 The present invention relates to a stent, particularly a galvanic corrosion stent in which a connecting portion is cut by galvanic corrosion after being placed in a living body.
　従来より、患者への侵襲が低いため、狭心症や心筋梗塞などの虚血性心疾患は、冠動脈の狭窄部に対する経皮経管的冠動脈形成術（ＰＴＣＡ）等により、大腿動脈や頚動脈の虚血性疾患などはこれらの動脈の狭窄部に対する経皮経管的血管形成術（ＰＴＡ）等により治療が行われている。これらの治療法はいずれも、先端に小さく折りたたまれたバルーンを装着したカテーテルを用いて、狭窄または閉塞してしまった血管を拡張することにより、血液の流れを確保、再開させる手技である。また、拡張した血管が再狭窄または閉塞するのを防止するため、金属製のステントを留置して血管の開存性を確保する治療が行われている。ステントは、一般的には１本の金属パイプから切り出されたものや、金属線からなるメッシュ状、コイル状等のものがあるが、いずれも縮径可能な管状構造を有し、縮径状態でカテーテルにより血管内に挿入され、狭窄部において血管内腔を機械的に支持するよう拡径され留置されるものである。また、Ｘ線透視下でステントの位置を良好に確認できるように、ステント端部にＸ線不透過性金属材料がマーカーとして設置されているものもある。 Conventionally, ischemic heart diseases such as angina pectoris and myocardial infarction are less likely to invade patients, such as percutaneous transluminal coronary angioplasty (PTCA) for stenosis of coronary arteries. Hematologic diseases and the like are treated by percutaneous transluminal angioplasty (PTA) or the like for the stenosis of these arteries. Each of these treatment methods is a technique for securing and resuming blood flow by dilating a blood vessel that has been narrowed or occluded by using a catheter equipped with a balloon folded at the tip. Further, in order to prevent the dilated blood vessel from restenosis or occlusion, a treatment for securing the patency of the blood vessel by placing a metal stent is performed. Stents are generally cut out from a single metal pipe or meshed or coiled of metal wire, but all have a tubular structure that can be reduced in diameter, and are in a reduced diameter state. The catheter is inserted into the blood vessel by the catheter, and the diameter is expanded and placed so as to mechanically support the blood vessel lumen in the stenosis. In some cases, a radiopaque metallic material is provided as a marker at the end of the stent so that the position of the stent can be confirmed well under fluoroscopy.
　一般にステントには、例えば、特許文献１に示されるように、隣り合う円筒要素同士をつなぐ相互連結要素（連結部）と呼ばれる部位が存在する。この連結部はステントの長手方向の形状を確保し、拡張後の血管のリモデリングを防ぐラジアルフォースを発生させるため必要である。 In general, as shown in Patent Document 1, for example, a stent has a portion called an interconnecting element (connecting portion) that connects adjacent cylindrical elements. This connecting portion is necessary to secure the shape of the stent in the longitudinal direction and to generate a radial force that prevents remodeling of the blood vessel after expansion.
特開平６－１８１９９３号公報（ＵＳ６０５６７７６Ａ）Japanese Laid-Open Patent Publication No. 6-181993 (US6056776A)
　血管拡張後、一定期間は血管のリモデリングを防ぐラジアルフォースが必要であるが、その後、ラジアルフォースは必要なくなる。むしろ、この時期にはそのリジッドな特性が血管への余計なストレスを生じさせる恐れすらある。 After the vasodilation, a radial force that prevents remodeling of the blood vessel is necessary for a certain period, but after that, the radial force is no longer necessary. Rather, the rigid properties can even cause extra stress on the blood vessels at this time.
　本発明はこのような実情に鑑みてなされたものであり、その目的とするところは、拡張後初期には十分なラジアルフォースを発生するが、拡張後一定時間が経過した後、そのリジッドな特性による血管等の生体管腔への余計なストレスを解放することができるステントを提供することである。 The present invention has been made in view of such circumstances, and its purpose is to generate a sufficient radial force in the initial stage after expansion, but its rigid characteristics after a certain period of time has elapsed after expansion. It is an object of the present invention to provide a stent capable of relieving unnecessary stress on a living body lumen such as a blood vessel due to the above.
　本発明者は、上記の問題を解決すべく、鋭意研究を行った。その結果、連結部の少なくとも一部に、環状体を構成するステント材料よりも電位的に貴な金属を設け、その金属と、ステント材料との間でガルバニック腐食（異種金属間腐食）を生じさせ、その連結部を切断することができるステントを提供することによって、上記課題を解決することができることを見出した。 The present inventor conducted intensive research to solve the above problems. As a result, at least a part of the connecting portion is provided with a metal that is more noble than the stent material constituting the annular body, and galvanic corrosion (corrosion between different metals) occurs between the metal and the stent material. The present inventors have found that the above problem can be solved by providing a stent capable of cutting the connecting portion.
　すなわち、線状構成要素により構成され、生体内への留置操作時に変形することにより生体管腔に密着するガルバニック腐食ステントであって、前記ステントは、前記線状構成要素により環状に形成された環状体が、軸方向に複数配列するとともに、隣り合う環状体が連結部により連結されたものであり、前記環状体は、第１の金属材料により形成されており、前記連結部の少なくとも一部は、前記第１の金属材料より貴な第２の金属材料により形成され、生体内に留置された後、ガルバニック腐食によって前記連結部が切断される、ガルバニック腐食ステントを提供することによって上記課題を解決することができることを見出し、本発明を完成するに至った。 That is, a galvanic erosion stent that is composed of linear components and is in close contact with a living body lumen by being deformed during an indwelling operation in a living body, and the stent is annularly formed by the linear components. A plurality of bodies are arranged in the axial direction, and adjacent annular bodies are connected by a connecting portion, and the annular body is formed of a first metal material, and at least a part of the connecting portion is The above-mentioned problem is solved by providing a galvanic corrosion stent that is formed of a second metal material that is more noble than the first metal material, is placed in a living body, and then the connection portion is cut by galvanic corrosion. As a result, the present invention has been completed.
　本発明によれば、拡張後初期には十分なラジアルフォースを発生するが、拡張後一定時間が経過した後に、生体管腔への余計なストレスを解放することができるステントを提供することができる。 According to the present invention, it is possible to provide a stent that generates sufficient radial force in the initial stage after expansion, but can release extra stress on the living body lumen after a certain time has elapsed after expansion. .
本発明の実施形態に係るガルバニック腐食ステントを示す図である。It is a figure which shows the galvanic corrosion stent which concerns on embodiment of this invention. 実施形態１による、図１に示されるガルバニック腐食ステントにおける点線で囲まれた部分３の部分拡大図である。FIG. 2 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 1; 実施形態２による、図１に示されるガルバニック腐食ステントにおける点線で囲まれた部分３の部分拡大図である。FIG. 4 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 2. 実施形態３による、図１に示されるガルバニック腐食ステントにおける点線で囲まれた部分３の部分拡大図である。FIG. 6 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 3; ガルバニック電流を測定するための装置を示す図である。It is a figure which shows the apparatus for measuring a galvanic current. 参考例２におけるガルバニック電流の測定結果を示す図である。It is a figure which shows the measurement result of the galvanic current in the reference example 2.
　以下、本発明の実施の形態を説明する。なお、本発明は、以下の実施の形態のみには限定されない。また、図面の寸法比率は、説明の都合上誇張されており、実際の比率とは異なる場合がある。また、本明細書において、範囲を示す「Ｘ～Ｙ」は「Ｘ以上Ｙ以下」を意味し、「重量」と「質量」、「重量％」と「質量％」および「重量部」と「質量部」は同義語として扱う。また、特記しない限り、操作および物性等は室温（２０～２５℃）／相対湿度４０～５０％の条件で測定する。 Hereinafter, embodiments of the present invention will be described. In addition, this invention is not limited only to the following embodiment. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios. In the present specification, “X to Y” indicating a range means “X or more and Y or less”, “weight” and “mass”, “weight%” and “mass%”, “part by weight” and “weight part”. “Part by mass” is treated as a synonym. Unless otherwise specified, operations and physical properties are measured under conditions of room temperature (20 to 25 ° C.) / Relative humidity 40 to 50%.
　本発明は、線状構成要素により構成され、生体内への留置操作時に変形することにより生体管腔に密着するガルバニック腐食ステントであって、前記ステントは、前記線状構成要素により環状に形成された環状体が、軸方向に複数配列するとともに、隣り合う環状体が連結部により連結されたものであり、前記環状体は、第１の金属材料により形成されており、前記連結部の少なくとも一部は、前記第１の金属材料より貴な第２の金属材料により形成され、生体内に留置された後、ガルバニック腐食によって前記連結部が切断される、ガルバニック腐食ステントである。なお、本明細書において「ガルバニック腐食ステント」を単に「ステント」とも称する。 The present invention is a galvanic erosion stent that is composed of linear components and is in close contact with a living body lumen by being deformed during an indwelling operation in a living body, and the stent is formed in an annular shape by the linear components. A plurality of annular bodies are arranged in the axial direction, and adjacent annular bodies are connected by a connecting portion, and the annular body is formed of a first metal material, and at least one of the connecting portions. The part is a galvanic corrosion stent that is formed of a second metal material that is nobler than the first metal material, and is placed in a living body, and then the connection part is cut by galvanic corrosion. In the present specification, the “galvanic corrosion stent” is also simply referred to as “stent”.
　上記述べたように、血管拡張後、一定期間は血管のリモデリングを防ぐラジアルフォースが必要であるが、その後、ラジアルフォースは必要なくなる。むしろ、この時期にはそのリジッドな特性が血管への余計なストレスを生じさせる恐れすらある。したがって、このリジッドな特性による血管への余計なストレスを解放する方が望ましい。本発明においては、このストレスの解放を、ガルバニック腐食を利用して行う。 As described above, a radial force that prevents remodeling of the blood vessel is necessary for a certain period after the vasodilation, but after that, the radial force is no longer necessary. Rather, the rigid properties can even cause extra stress on the blood vessels at this time. Therefore, it is desirable to release the extra stress on the blood vessels due to this rigid characteristic. In the present invention, this stress is released by utilizing galvanic corrosion.
　より詳しく説明すると、金属はそれぞれ固有の電位を持つ。種類の異なる金属を接触させて、電解質溶液に浸漬すると、両者の電位が異なるため、卑な金属（イオン化傾向の大きい金属）と貴な金属（イオン化傾向の小さい金属）との間に電位差（ガルバニック電位）が生じ電池（局部電池、ガルバニック電池）が形成され、電流が流れ（局部電流）、腐食が生じる。このような異種金属を電極とした局部電池の形成による電気化学的反応で生じる腐食を、ガルバニック腐食（異種金属間腐食または局部電池腐食と呼ばれることもある）と呼ぶ。本発明のガルバニック腐食ステントは、線状構成要素により環状に形成された環状体が、軸方向に複数配列するとともに、隣り合う環状体が連結部により連結されてなるが、この連結部をガルバニック腐食の原理を利用して切断することによって、ステントが有するラジアルフォースを減少させ、そのリジッドな特性による血管への余計なストレスを解放する。なお、本明細書における「一定期間」の具体的な期間としては、１～数ヶ月程度であることが好ましく、例えば、１～６ヶ月、２～５ヶ月、あるいは３～４ヶ月程度を想定している。これ以上の期間をかけて切断させてもよいが、ただ１年、２年以上になると血管への余計なストレスが必要以上に続いてしまうため好ましくない場合がある。なお上記期間は一般的なものであり、患者の重篤度、年齢などによって必ずしも上記とはならない場合があることは言うまでもない。 To explain in more detail, each metal has its own potential. When different types of metals are brought into contact and immersed in an electrolyte solution, the potentials of the two differ, so there is a potential difference (galvanic) between a base metal (a metal with a high ionization tendency) and a noble metal (a metal with a low ionization tendency). Potential) occurs to form a battery (local battery, galvanic battery), current flows (local current), and corrosion occurs. Corrosion caused by an electrochemical reaction due to formation of a local battery using such a foreign metal as an electrode is called galvanic corrosion (sometimes referred to as intermetallic corrosion or local battery corrosion). In the galvanic corrosion stent of the present invention, a plurality of annular bodies formed in an annular shape by linear components are arranged in the axial direction and adjacent annular bodies are connected by a connecting portion. By cutting using this principle, the radial force of the stent is reduced, and the extra stress on the blood vessels due to its rigid characteristics is released. Note that the specific period of the “certain period” in the present specification is preferably about 1 to several months, for example, assuming 1 to 6 months, 2 to 5 months, or about 3 to 4 months. ing. It may be cut over a longer period, but it may be unpreferable if it is only 1 year or 2 years or more because excessive stress on the blood vessel continues more than necessary. Needless to say, the above period is general and may not always be the above depending on the severity and age of the patient.
　本発明のステントにおいては、このガルバニック電位を生じさせるため、第１の金属材料と、第２の金属材料とを含んで構成される。より具体的には、第１の金属材料で形成された線状構成要素が環状に形成されてなる環状体が、軸方向に複数配列するとともに、隣り合う環状体が、前記第１の金属材料より貴な第２の金属材料を含んで形成された連結部により連結されている。そして、第１の金属材料と、第２の金属材料との間に自然浸漬電位の差が存在することによって局部電流が発生しガルバニック腐食が起こり、生体内においてその連結部を切断することができる。電位差が大きいほど、流れる局部電流が増大して、腐食も促進されることになる。この際の自然浸漬電位の差は特に制限はないが、上記一定期間経過後に切断されるような自然浸漬電位の差が好ましく、例えば、第１の金属材料と、第２の金属材料の自然浸漬電位の差が２００ｍＶを超えて１０００ｍＶ以下であると好ましく、２１０～８００ｍＶ程度であるとより好ましく、２１０～５００ｍＶ程度であるとさらに好ましく、２１０～３００ｍＶ程度であるとよりさらに好ましく、２１０～２５０ｍＶ程度であると特に好ましい。２００ｍＶ以下であると電流が流れにくくガルバニック腐食が起こりにくい場合がある。１０００ｍＶを超えると、腐食が早く進みすぎて血管のリモデリングを防ぐことができない場合がある。 The stent of the present invention includes a first metal material and a second metal material in order to generate this galvanic potential. More specifically, a plurality of annular bodies formed by annularly forming linear components formed of the first metal material are arranged in the axial direction, and the adjacent annular bodies are the first metal material. It is connected by a connecting portion formed to contain a noble second metal material. Then, when a difference in natural immersion potential exists between the first metal material and the second metal material, local current is generated, galvanic corrosion occurs, and the connection portion can be cut in the living body. . The greater the potential difference, the greater the local current that flows and the more corrosion is promoted. The difference in natural immersion potential at this time is not particularly limited, but a difference in natural immersion potential that is cut after the elapse of the predetermined period is preferable. For example, natural immersion between the first metal material and the second metal material is preferable. The difference in potential is more than 200 mV and preferably 1000 mV or less, more preferably about 210 to 800 mV, more preferably about 210 to 500 mV, still more preferably about 210 to 300 mV, and about 210 to 250 mV. Is particularly preferred. If it is 200 mV or less, current may hardly flow and galvanic corrosion may not easily occur. If it exceeds 1000 mV, corrosion may progress too quickly, preventing remodeling of blood vessels.
　なお、本明細書において、「自然浸漬電位」は、ＪＩＳ　Ｔ０３０２：２０００に記載される方法によって測定され、具体的には、下記方法によって測定された値（ｍＶ）である。すなわち、まず、試料（第１の金属材料および第２の金属材料）をそれぞれ適当なサイズに切断する。切断時の影響を除去するため、試料を耐水研磨紙を用いて流水下で研磨する。この際、研磨紙は、目の粗いもの（１５０番）から始め、最終的に６００番まで使用する。研磨後、試料を蒸留水中で５分間超音波洗浄する。洗浄後、試料に導線を接続する。なお、試料と導線の接続方法は、試料の形状により、半田付け、ドータイト、クリップ、ネジ止めなどから適宜選択する。次に、試料が１平方ｃｍのみ露出するように、導線との接続部を含めてシール剤で被覆する。被覆後、２４時間以内に、以下の評価に供する。ＰＢＳ溶液（組成：８．０ｇ／Ｌ　ＮａＣｌ、０．２ｇ／Ｌ　ＫＣｌ、１．１５ｇ／Ｌ　Ｎａ２ＨＰＯ４、０．２ｇ／Ｌ　ＫＨ２ＰＯ４、ｐＨ　７．２～７．６）を入れた電解セルを恒温浴槽内に入れ、ＰＢＳ溶液の温度を３７℃に保持する。ＰＢＳ溶液に高純度窒素ガスを３０分以上バブリングする。その後、上記で調製した試料をＰＢＳ溶液に浸漬させる。試料に生じる電位をエレクトロメーター（北斗電工株式会社製、商品名：ＨＥ－１０４）で測定する。なお、測定は、３７℃で１時間浸漬した状態で行い、１時間後の値を自然浸漬電位（ｍＶ）とする。 In the present specification, the “natural immersion potential” is measured by the method described in JIS T0302: 2000, and specifically, is a value (mV) measured by the following method. That is, first, the sample (first metal material and second metal material) is cut into appropriate sizes. In order to remove the influence at the time of cutting, the sample is polished under running water using water-resistant abrasive paper. At this time, the abrasive paper starts from the coarse one (No. 150) and finally uses up to No. 600. After polishing, the sample is ultrasonically cleaned in distilled water for 5 minutes. After cleaning, connect the conductor to the sample. In addition, the connection method of a sample and a conducting wire is appropriately selected from soldering, dotite, clip, screwing, and the like depending on the shape of the sample. Next, it coat | covers with a sealing compound including a connection part with conducting wire so that a sample may expose only 1 square cm. The following evaluation is performed within 24 hours after coating. PBS solution (composition: 8.0 g / L NaCl, 0.2 g / L KCl, 1.15 g / L Na 2 HPO 4 , 0.2 g / L KH 2 PO 4 , pH 7.2 to 7.6) The electrolysis cell is placed in a thermostatic bath, and the temperature of the PBS solution is maintained at 37 ° C. A high purity nitrogen gas is bubbled through the PBS solution for 30 minutes or longer. Thereafter, the sample prepared above is immersed in a PBS solution. The potential generated in the sample is measured with an electrometer (trade name: HE-104, manufactured by Hokuto Denko Co., Ltd.). In addition, a measurement is performed in the state immersed at 37 degreeC for 1 hour, and let the value after 1 hour be a natural immersion potential (mV).
　また、本明細書におけるガルバニック電流は、参照極として飽和カロメル電極（saturated calomel electrode, SCE）を使用した際の値とする。 Also, the galvanic current in this specification is a value when a saturated calomel electrode (SCE) is used as a reference electrode.
　ここで、本発明のガルバニック腐食ステント（環状体、連結部）の厚みは、血管のリモデリングを防ぐために必要なラジアルフォースを有し、血流を阻善しない程度であれば特に限定されないが、例えば１～１０００μｍの範囲が好ましく、５０～３００μｍの範囲がより好ましい。 Here, the thickness of the galvanic corrosion stent (annular body, connecting portion) of the present invention is not particularly limited as long as it has a radial force necessary to prevent remodeling of blood vessels and does not obstruct blood flow. For example, the range of 1 to 1000 μm is preferable, and the range of 50 to 300 μm is more preferable.
　また、本発明のガルバニック腐食ステントは、従来使用されるステントと同様に、バルーンエクスパンダブルステント(balloon-expandable stent)（バルーン拡張型ステント）またはセルフエクスパンダブルステント(self-expandable stent)（自己拡張型ステント）のいずれであってもよい。 In addition, the galvanic erosion stent of the present invention is similar to a conventionally used stent in that a balloon-expandable stent (balloon-expandable stent) or a self-expandable stent (self-expandable stent) (self Any of expandable stents may be used.
　そして、本発明のガルバニック腐食ステントの形状は、特に制限されないが、血管等の生体管腔内に安定して留置するに足る強度を有することが必要である。この点、本発明は、連結部として金属材料から構成される第２の金属材料を含むため、同じく金属材料から構成される第１の金属材料との接合強度を十分高く設計することができ、血管等の生体管腔内に安定して留置することができる。一方、連結部に生分解性ポリマー（例えばポリ乳酸）が含まれる場合、ポリ乳酸は延性に乏しいため生体管腔内への留置完了前に破断する場合がある。これに対して本発明によれば、連結部を構成する材料として、金属材料である第２の金属材料を含むため、生体管腔内への留置完了前に破断する可能性を低くすることができる。なお、ステントの具体的な形状としては、例えば、繊維を編み上げて円筒状に形成したものや、管状体に開口部を設けたもの等が挙げられる。 The shape of the galvanic erosion stent of the present invention is not particularly limited, but it is necessary to have sufficient strength to be stably placed in a biological lumen such as a blood vessel. In this respect, since the present invention includes the second metal material composed of the metal material as the connecting portion, the joint strength with the first metal material also composed of the metal material can be designed sufficiently high. It can be stably placed in a living body lumen such as a blood vessel. On the other hand, when a biodegradable polymer (for example, polylactic acid) is contained in the connecting portion, polylactic acid is poor in ductility and may break before completion of placement in the body lumen. On the other hand, according to the present invention, since the second metal material, which is a metal material, is included as the material constituting the connecting portion, the possibility of breaking before completion of placement in the living body lumen can be reduced. it can. In addition, as a specific shape of a stent, the thing which formed the fiber by knitting a fiber, the thing which provided the opening part in the tubular body, etc. are mentioned, for example.
　以下では、本発明のガルバニック腐食ステントの一実施形態として、バルーン拡張型ステントの例を挙げて、図１に示されるステントを説明する。図１に示されるように、ステント１は、線状構成要素２により環状に形成された波状環状体が、軸方向に複数配列するとともに、隣り合う波状環状体が連結部Ｃにより連結され、両末端部が開口し、該両末端部の間を長手方向に延在して構成される、円筒体である。本実施形態において、環状体が、波状環状体であることによって、大きな拡径率が得られ、実使用上においてよく求められる過拡張に対応できるという効果を有する。 Hereinafter, as an embodiment of the galvanic corrosion stent of the present invention, an example of a balloon expandable stent will be described and the stent shown in FIG. 1 will be described. As shown in FIG. 1, in the stent 1, a plurality of wave-like annular bodies formed in an annular shape by the linear component 2 are arranged in the axial direction, and adjacent wave-like annular bodies are connected by a connecting portion C. It is a cylindrical body having an end portion opened and extending in the longitudinal direction between the both end portions. In the present embodiment, since the annular body is a wave-like annular body, a large diameter expansion rate is obtained, and it has an effect of being able to cope with the overexpansion often required in actual use.
　本実施形態では、隣り合う波状環状体同士は、連結部により連結されている。円筒体（ステント）の側面は、その外側面と内側面とを連通する多数の切欠部を有し、この切欠部が変形することによって、円筒体の径方向に拡縮可能な構造になっている。そして、血管等の生体管腔内に留置されると、その形状を維持する。 In the present embodiment, the adjacent wavy annular bodies are connected by a connecting portion. The side surface of the cylindrical body (stent) has a large number of notches communicating with the outer side surface and the inner side surface, and has a structure that can expand and contract in the radial direction of the cylindrical body by deforming the notch portions. . And if it is detained in living body lumens, such as a blood vessel, the shape will be maintained.
　図１に示す形態において、ステント１は、内側に切欠部が形成された略菱形の要素Ａを基本単位とする。略菱形の要素Ａは、隣り合う二つの線状構成要素２と；各線状要素２同士を連結する、相対的に長さが短い連結部Ｃである第１連結部Ｃ１と；により構成される。また、略菱形の要素Ａがその短軸方向に連続して配置され結合することによって、環状に形成された環状ユニットＢをなしている。すなわち、環状ユニットＢは、隣り合う二つの波状環状体と；各波状環状体同士を連結する第１連結部Ｃ１；とにより構成される。 In the form shown in FIG. 1, the stent 1 has a substantially rhombic element A with a notch formed inside as a basic unit. The substantially rhombic element A includes two adjacent linear constituent elements 2; and a first connecting part C1 that connects the linear elements 2 to each other and has a relatively short connecting part C. . Moreover, the substantially diamond-shaped element A is continuously arranged and coupled in the minor axis direction to form an annular unit B formed in an annular shape. That is, the annular unit B includes two adjacent wave-like annular bodies; and a first connecting portion C1 that connects the wave-like annular bodies.
　環状ユニットＢは、軸方向に複数配列されており、隣り合う各環状ユニットＢは、相対的に長さが長い連結部Ｃである、第２連結部Ｃ２によりさらに連結されている。これにより隣り合う各環状ユニットＢは、互いに一部が結合した状態でその軸方向に連続して配置される。 A plurality of annular units B are arranged in the axial direction, and each adjacent annular unit B is further connected by a second connecting part C2, which is a connecting part C having a relatively long length. Thereby, each adjacent annular unit B is continuously arranged in the axial direction in a state in which a part thereof is coupled to each other.
　ステント１は、このような構成により、両末端部が開口し、該両末端部の間を長手方向に延在する円筒体をなしている。そして、ステント１の側面は、略菱形の切欠部（略菱形の要素Ａ）を有しており、この切欠部が変形することによって、ステントの径方向に拡縮可能な構造になっている。 With such a configuration, the stent 1 has a cylindrical body that is open at both ends and extends between the ends in the longitudinal direction. And the side surface of the stent 1 has a substantially rhombus notch (substantially rhombus element A), and the notch is deformed so that the stent 1 can expand and contract in the radial direction.
　本実施形態におけるステントは、線状構成要素２により環状に形成された環状体（波状環状体）が、軸方向に複数配列するとともに、隣り合う環状体が連結部Ｃ（第１連結部Ｃ１、第２連結部Ｃ２）により連結されたものであり、環状体は、第１の金属材料により形成されており、連結部Ｃ（第１連結部Ｃ１、第２連結部Ｃ２）の少なくとも一部は、当該第１の金属材料より貴な第２の金属材料により形成されている。このように、連結部Ｃ（第１連結部Ｃ１、第２連結部Ｃ２）の少なくとも一部が、第２の金属材料により形成されていると、第１の金属材料と第２の金属材料との間に電位差（ガルバニック電位）が生じることによって電流が流れ（局部電流）、腐食が生じ、一定期間後にその連結部は切断され、リジッドな特性による血管への余計なストレスが解放される。 In the stent according to the present embodiment, a plurality of annular bodies (waved annular bodies) formed in an annular shape by the linear component 2 are arranged in the axial direction, and adjacent annular bodies are connected to the connecting portion C (first connecting portion C1, The second connecting portion C2) is connected, the annular body is formed of the first metal material, and at least a part of the connecting portion C (first connecting portion C1, second connecting portion C2) is formed. The second metal material is nobler than the first metal material. Thus, when at least a part of the connecting portion C (the first connecting portion C1 and the second connecting portion C2) is formed of the second metal material, the first metal material and the second metal material When a potential difference (galvanic potential) is generated during this period, current flows (local current) and corrosion occurs, and after a certain period, the connecting portion is disconnected, thereby releasing extra stress on the blood vessel due to rigid characteristics.
　図２は、好ましい実施形態である実施形態１による、図１に示されるガルバニック腐食ステントにおける点線で囲まれた部分３の部分拡大図である。図２に示されるように、本実施形態のステントにおいては、第１連結部Ｃ１の中央部が、第２の金属材料５によって形成されている。そして、第１連結部Ｃ１の中央部以外の部分は、その第２の金属材料５を介するようにして、第１の金属材料４によって形成されている。つまりは、第１の金属材料４によって形成されている第１連結部Ｃ１を分断するように、第２の金属材料５が設けられている。本実施形態においては、第１連結部Ｃ１を構成する第１の金属材料４と、同じく第１連結部Ｃ１を構成する第２の金属材料５との間において電位差（ガルバニック電位）が生じることで電流が流れ（局部電流）、隙間腐食が生じ、一定期間経過後にその連結部は切断され、リジッドな特性による血管への余計なストレスが解放される。 FIG. 2 is a partial enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 1 which is a preferred embodiment. As shown in FIG. 2, in the stent of the present embodiment, the central portion of the first connecting portion C <b> 1 is formed of the second metal material 5. And parts other than the center part of the 1st connection part C1 are formed of the 1st metal material 4 so that the 2nd metal material 5 may be interposed. That is, the 2nd metal material 5 is provided so that the 1st connection part C1 currently formed with the 1st metal material 4 may be parted. In the present embodiment, a potential difference (galvanic potential) is generated between the first metal material 4 constituting the first connection portion C1 and the second metal material 5 similarly constituting the first connection portion C1. Current flows (local current), crevice corrosion occurs, the connection is cut after a certain period of time, and extra stress on the blood vessels due to rigid characteristics is released.
　また、本実施形態において、第２の金属材料が第１の金属材料よりも比重が重く、Ｘ線不透過性が高い場合、このような第２の金属材料が設けられることによってＸ線透視下でステントの位置を良好に確認できるという効果がある。つまり、通常のステントには、Ｘ線透視下でステントの位置を良好に確認できるように、ステント端部にＸ線不透過性金属材料がマーカーとして特別に設置されていることがある。しかし、端部にのみにＸ線不透過性マーカーが設けられているステントでは、ステント全体の形状までは把握できず、留置部位付近に存在する分岐血管の全部または一部をステント本体で塞いでしまう場合があるという問題がある。これに対し本実施形態において、第２の金属材料として第１の金属材料よりも比重が重く、Ｘ線不透過性が高い金属を使用することにより、第２の金属材料に、ガルバニック腐食をさせて連結部を切断するという効果の他に、別途のマーカーを設けることなくステントの視認性に優れるという効果を付与する。それだけでなく、第２の金属材料が、ステントを構成する全体の連結部に設けられているため、生体管腔内により安全に留置させることができる。すなわち留置の際に優れたＸ線不透過性によりステントの位置が明確に分かり手術が容易になる。ただし、本発明においては、別途のマーカーをさらにステント本体（基材）に設けることを妨げるものではない。 Further, in the present embodiment, when the second metal material has a higher specific gravity than the first metal material and has a high radiopacity, such a second metal material is provided so that the X-ray fluoroscopy can be performed. With this, there is an effect that the position of the stent can be confirmed well. That is, in a normal stent, a radiopaque metallic material may be specially installed as a marker at the end of the stent so that the position of the stent can be confirmed well under fluoroscopy. However, in a stent in which a radiopaque marker is provided only at the end, the shape of the entire stent cannot be grasped, and all or part of the branching blood vessels existing near the indwelling site are blocked with the stent body. There is a problem that it may end up. On the other hand, in this embodiment, the second metal material is made of galvanic corrosion by using a metal having a higher specific gravity and higher radiopacity than the first metal material. In addition to the effect of cutting the connecting portion, the effect of excellent visibility of the stent is provided without providing a separate marker. In addition, since the second metal material is provided in the entire connecting portion constituting the stent, the second metal material can be safely placed in the living body lumen. In other words, the superior radiopacity during placement makes the position of the stent clear and facilitates surgery. However, in this invention, it does not prevent providing a separate marker in a stent main body (base material) further.
　また、実施形態１は、後述の実施形態２、３と比較して、血液等の体液と接触する第２の金属材料の表面積が小さいため、隙間腐食を生じさせる速度（腐食速度）を遅くする効果があり、第１の金属材料と第２の金属材料の組み合わせが速すぎる腐食速度をもたらす場合に、本実施形態を選択すれば適切な腐食速度が得られるとの効果もある。 In addition, the first embodiment has a lower surface area of the second metal material that comes into contact with a body fluid such as blood than the second and third embodiments described later, and therefore the rate at which crevice corrosion occurs (corrosion rate) is reduced. There is an effect, and when the combination of the first metal material and the second metal material brings about an excessively high corrosion rate, there is also an effect that an appropriate corrosion rate can be obtained by selecting this embodiment.
　図３は、別の好ましい実施形態である実施形態２による、図１に示されるガルバニック腐食ステントにおける点線で囲まれた部分３の部分拡大図である。図３に示されるように、本実施形態のステントにおいては、第１連結部Ｃ１の両端部が第２の金属材料５によって形成されている。そして、第１連結部Ｃ１の両端部以外の部分は、第１の金属材料４によって形成されている。本実施形態においても、第１連結部Ｃ１を構成する第１の金属材料４と、同じく第１連結部Ｃ１を構成する第２の金属材料５との間において電位差（ガルバニック電位）が生じることで電流が流れ（局部電流）、隙間腐食が生じ、一定期間経過後にその連結部は切断され、リジッドな特性による血管への余計なストレスが解放される。また、本実施形態においても、上記の好ましい実施形態で説明したものと同様に、第２の金属材料が、第１の金属材料よりも比重が重く、Ｘ線不透過性が高い場合、Ｘ線透視下でステントの位置を良好に確認できるという効果がある。特に本実施形態においては、１つの連結部に２箇所、第２の金属材料が設けられているためさらに視認性が向上する。ただし、本発明においては、別途のマーカーをさらにステント本体（基材）に設けることを妨げるものではない。 FIG. 3 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to another preferred embodiment, Embodiment 2. FIG. As shown in FIG. 3, in the stent of the present embodiment, both end portions of the first connecting portion C <b> 1 are formed of the second metal material 5. Then, portions other than both end portions of the first connecting portion C <b> 1 are formed of the first metal material 4. Also in the present embodiment, a potential difference (galvanic potential) is generated between the first metal material 4 constituting the first connection portion C1 and the second metal material 5 similarly constituting the first connection portion C1. Current flows (local current), crevice corrosion occurs, the connection is cut after a certain period of time, and extra stress on the blood vessels due to rigid characteristics is released. Also in this embodiment, in the same manner as described in the above preferred embodiment, when the second metal material has a higher specific gravity than the first metal material and has a high radiopacity, There is an effect that the position of the stent can be confirmed well under fluoroscopy. In particular, in this embodiment, visibility is further improved since the second metal material is provided at two locations in one connecting portion. However, in this invention, it does not prevent providing a separate marker in a stent main body (base material) further.
　また、本形態によれば、切断後に残留する連結部の体積が小さくなるとの効果もある。 Further, according to this embodiment, there is an effect that the volume of the connecting portion remaining after cutting is reduced.
　なお、本実施形態の変形例としては、第１連結部Ｃ１の両端部の他に、中央部にさらに第２の金属材料が設けられていてもよいし、それ以上第２の金属材料が設けられていてもよい。ただし作製上の観点を考慮すると、第２の金属材料が設けられる箇所は、一つの連結部において５個までが好ましい。このように第２の金属材料の設置数、幅などによってストレス解放時期を容易に調節することができる。 As a modification of the present embodiment, a second metal material may be further provided in the central portion in addition to the both end portions of the first connecting portion C1, or a second metal material may be further provided. It may be done. However, from the viewpoint of manufacturing, it is preferable that the number of places where the second metal material is provided is up to five in one connecting portion. Thus, the stress release time can be easily adjusted by the number of installed second metal materials, the width, and the like.
　図４は、さらに別の好ましい実施形態である実施形態３による、図１に示されるガルバニック腐食ステントにおける点線で囲まれた部分３の部分拡大図である。図４に示されるように、本実施形態のステントにおいては、第１連結部Ｃ１はすべて第２の金属材料５によって形成されている。本実施形態においては、波状環状体（線状構成要素２）を構成する第１の金属材料４と、第１連結部Ｃ１を構成する第２の金属材料５との間において電位差（ガルバニック電位）が生じることで電流が流れ（局部電流）、隙間腐食が生じ、一定期間経過後にその連結部は切断され、リジッドな特性による血管への余計なストレスが解放される。また、本実施形態においても、上記の好ましい実施形態で説明したものと同様に、第２の金属材料が、第１の金属材料よりも比重が重く、Ｘ線不透過性が高い場合、Ｘ線透視下でステントの位置を良好に確認できるという効果がある。特に、第１連結部Ｃ１全体が第２の金属材料５によって形成されているという観点からさらに視認性が向上するという効果がある。ただし、本発明においては、別途のマーカーをさらにステント本体（基材）に設けることを妨げるものではない。また本形態によればステントの作製が容易という効果もある。 FIG. 4 is a partially enlarged view of a portion 3 surrounded by a dotted line in the galvanic corrosion stent shown in FIG. 1 according to Embodiment 3, which is still another preferred embodiment. As shown in FIG. 4, in the stent of the present embodiment, all the first connecting portions C <b> 1 are made of the second metal material 5. In the present embodiment, a potential difference (galvanic potential) between the first metal material 4 constituting the corrugated annular body (linear component 2) and the second metal material 5 constituting the first connecting portion C1. As a result of this, current flows (local current), crevice corrosion occurs, the connection portion is cut after a certain period of time, and extra stress on the blood vessel due to rigid characteristics is released. Also in this embodiment, in the same manner as described in the above preferred embodiment, when the second metal material has a higher specific gravity than the first metal material and has a high radiopacity, There is an effect that the position of the stent can be confirmed well under fluoroscopy. In particular, there is an effect that the visibility is further improved from the viewpoint that the entire first connecting portion C1 is formed of the second metal material 5. However, in this invention, it does not prevent providing a separate marker in a stent main body (base material) further. Moreover, according to this embodiment, there is an effect that the production of the stent is easy.
　実施形態１～３では、各第１連結部Ｃ１における第２の金属材料５の形態について説明したが、この第１の金属材料４より貴な第２の金属材料５の、血液等の体液に接する表面積（つまり露出している表面積）を変化させることにより腐食速度を調整でき、およその切断までに要する時間を調整することもできる。その表面積としては、表面に露出している第１の金属材料４と第２の金属材料５の各接合界面部位の長さに０．０５～２０程度乗じたものが好ましく、０．１～１０程度乗じたものがより好ましい。この場合の表面積は、実施形態２のように１つの連結部に複数の第２の金属材料５で構成される部分が含まれる場合、その合計とする。なお、各接合界面部位の長さとは、第１の金属材料４と第２の金属材料５との界面で部分的に合金化されている部位（接合界面部位）があるが、その長さを意味する。 In the first to third embodiments, the form of the second metal material 5 in each first connection portion C1 has been described. However, the second metal material 5 that is noble than the first metal material 4 can be applied to body fluids such as blood. The corrosion rate can be adjusted by changing the surface area in contact (that is, the exposed surface area), and the time required for approximate cutting can also be adjusted. The surface area is preferably obtained by multiplying the length of each joint interface portion of the first metal material 4 and the second metal material 5 exposed on the surface by about 0.05 to 20, and 0.1 to 10 A product multiplied by a degree is more preferable. In this case, the surface area is the total when a portion composed of a plurality of second metal materials 5 is included in one connecting portion as in the second embodiment. The length of each bonding interface portion includes a portion (bonding interface portion) partially alloyed at the interface between the first metal material 4 and the second metal material 5. means.
　また、より具体的には、例えば第２の金属材料として金を、第１の金属材料としてＬ６０５を、それぞれ選択した場合、０．１～１０程度乗じたものが好ましく、０．２～５程度乗じたものがより好ましい。無論、上記の表面積等は、第１の金属材料、第２の金属材料の種類や、ステント全体の大きさ等に応じて適宜調整が可能であり、上記の範囲を逸脱するような値が選択されてももちろん構わない。 More specifically, for example, when gold is selected as the second metal material and L605 is selected as the first metal material, a value multiplied by about 0.1 to 10 is preferable, and about 0.2 to 5 is preferable. Those multiplied are more preferable. Of course, the surface area and the like can be appropriately adjusted according to the types of the first metal material and the second metal material, the size of the entire stent, etc., and values that deviate from the above range are selected. Of course it does not matter.
　なお、実施形態１～３では、第１連結部Ｃ１の少なくとも一部が第２の金属材料により形成されている形態について説明したが、第２連結部Ｃ２の少なくとも一部についても第２の金属材料により形成されていても無論よいし、第１連結部Ｃ１、第２連結部Ｃ２のいずれかであってもよい。また、連結部の長さが２種類である形態について説明したが、連結部の長さがすべて実質的に等しいステントであっても無論よいし、連結部の長さが３種類以上であってもよい。 In the first to third embodiments, the form in which at least a part of the first connecting part C1 is formed of the second metal material has been described. However, the second metal is also used in at least a part of the second connecting part C2. Of course, it may be formed of a material, or may be either the first connecting part C1 or the second connecting part C2. In addition, the description has been given of the form in which the length of the connecting portion is two types, but it is of course possible that the length of the connecting portion is substantially the same, and the length of the connecting portion is three or more types. Also good.
　また、実施形態１～３では、１つの連結部（第１連結部Ｃ１）のみに着目して説明したが、好ましくは１つのステントの中に含まれるすべての連結部に、第２の金属材料５で構成される部分が存在する。 In the first to third embodiments, the description has been given focusing on only one connecting portion (the first connecting portion C1). Preferably, the second metal material is included in all the connecting portions included in one stent. There is a part consisting of five.
　あるいはすべての連結部でなくても１つのステントにおける連結部の総数の２０～９０％、あるいは３０～８０％に第２の金属材料５で構成される部分が存在することでラジアルフォースを有意に減少させリジッドな特性による血管への余計なストレスを解放することができる。 Alternatively, even if not all of the connecting portions, the radial force is significantly increased by the presence of the portion made of the second metal material 5 in 20 to 90%, or 30 to 80% of the total number of connecting portions in one stent. Reduces and releases extra stress on blood vessels due to rigid characteristics.
　続いて、第１の金属材料および第２の金属材料などの本発明のステントを構成する成分の具体例について説明する。 Subsequently, specific examples of components constituting the stent of the present invention such as the first metal material and the second metal material will be described.
　［第１の金属材料］
　第１の金属材料は、通常医療分野においてステントとして使用されるものと同様の金属が使用でき、具体的には、ステンレス鋼、コバルト系合金、ニッケル－チタン系合金（Ｎｉ－Ｔｉ系合金）、タンタル、タンタル系合金、モリブデン、モリブデン系合金などが挙げられる。上記のうち、ステンレス鋼、コバルト系合金（例えば、Ｃｏ－Ｃｒ系合金）、ニッケル－チタン系合金（Ｎｉ－Ｔｉ系合金）のいずれかが好ましい。 [First metal material]
As the first metal material, metals similar to those used as stents in the normal medical field can be used. Specifically, stainless steel, cobalt alloy, nickel-titanium alloy (Ni-Ti alloy), Examples include tantalum, tantalum alloys, molybdenum, and molybdenum alloys. Of the above, stainless steel, cobalt-based alloy (for example, Co—Cr-based alloy), and nickel-titanium-based alloy (Ni—Ti-based alloy) are preferable.
　ここで、ステンレス鋼としては、通常医療分野において使用できるステンレス鋼が同様にして使用できるが、例えば、ＳＳ３０４、ＳＳ３１６Ｌ、ＳＳ４２０Ｊ２、ＳＳ６３０などが挙げられる。これらのうち、生体内での使用実績の観点から、ＳＳ３１６Ｌ（組成：炭素　０．０３５重量％以下、リン　０．０４重量％以下、硫黄　０．０３重量％以下、マンガン　２．００重量％以下、ケイ素　０．７５重量％以下、クロム　１６．００～１８．００重量％、ニッケル　１２．００～１５．００重量％、モリブデン　２．００～３．００重量％、残部　鉄）が好ましい。 Here, as the stainless steel, stainless steel that can be used in the normal medical field can be used in the same manner, and examples thereof include SS304, SS316L, SS420J2, SS630, and the like. Of these, SS316L (composition: carbon 0.035% by weight or less, phosphorus 0.04% by weight or less, sulfur 0.03% by weight or less, manganese 2.00% by weight or less, from the viewpoint of use in vivo, Silicon (0.75% by weight or less), chromium (16.00 to 18.00% by weight), nickel (12.00 to 15.00% by weight), molybdenum (2.00 to 3.00% by weight, balance iron) is preferable.
　また、コバルト系合金としても、通常医療分野において使用できるコバルト系合金が同様にして使用できるが、例えば、Ｌ６０５等のコバルト－クロム合金（Ｃｏ－Ｃｒ合金）、コバルト－ニッケル－クロム合金、ＭＰ３５Ｎ等のコバルト－ニッケル－クロム－モリブデン合金、コバルト－クロム－モリブデン合金などが挙げられる。これらのうち、強度、生体内での使用実績の観点から、Ｌ６０５（組成：クロム　１９．００～２１．００重量％、ニッケル　９．００～１１．００重量％、タングステン　１４．００～１６．００重量％、鉄　最大３．００重量％、マンガン　１．００～２．００重量％、炭素　０．０５～０．１５重量％、ケイ素　最大０．４０重量％、リン　最大０．０４０重量％、硫黄　最大０．０３０重量％、残部　コバルト）、ＭＰ３５Ｎ（組成：炭素　最大０．０２５重量％、リン　最大０．０１５重量％、硫黄　最大０．０１０重量％、マンガン　最大０．１５重量％、ケイ素　最大０．１５重量％、クロム　１９．００～２１．００重量％、ニッケル　３３．００～３７．００％重量、モリブデン　９．００～１０．５０％重量、チタン　最大１．００重量％、ホウ素　最大０．０１重量％、鉄　最大１．００重量％、残部　コバルト）が好ましく、特に、Ｌ６０５は、高強度・高延性を有するため薄肉かつ過拡張が容易に可能となり非常に好ましい。 Also, as the cobalt-based alloy, cobalt-based alloys that can be used in the normal medical field can be used in the same manner. For example, cobalt-chromium alloy (Co-Cr alloy) such as L605, cobalt-nickel-chromium alloy, MP35N, etc. And cobalt-nickel-chromium-molybdenum alloy and cobalt-chromium-molybdenum alloy. Of these, L605 (composition: chrome 19.00 to 21.00% by weight, nickel 9.00 to 11.00% by weight, tungsten 14.00 to 16.00 from the viewpoint of strength and use in vivo. Wt%, iron max. 3.00 wt%, manganese 1.00-2.00 wt%, carbon 0.05-0.15 wt%, silicon max 0.40 wt%, phosphorus max 0.040 wt%, sulfur Max 0.030 wt%, balance cobalt), MP35N (Composition: carbon max 0.025 wt%, phosphorus max 0.015 wt%, sulfur max 0.010 wt%, manganese max 0.15 wt%, silicon max 0 15% by weight, chromium 19.00-21.00% by weight, nickel 33.00-37.00% by weight, molybdenum 9.00-10.50% by weight, titanium Large 1.00% by weight, boron up to 0.01% by weight, iron up to 1.00% by weight, balance cobalt) are preferred, especially L605 has high strength and high ductility, so it is thin and easily overextensible. It is very preferable.
　また、ニッケル－チタン系合金としても、通常医療分野において使用できるニッケル－チタン系合金が同様にして使用できるが、例えば、約５０重量％～約６０重量％のニッケルを含有し、残部がチタンであるニッケル－チタン合金、ニッケル－チタン合金に銅を添加したニッケル－チタン－銅合金などが挙げられる。これらのうち、生体内での使用実績、超弾性特性の観点から、上記約５０重量％～約６０重量％のニッケルを含有し残部がチタンであるニッケル－チタン合金（ニチノール）が好ましい。 As the nickel-titanium-based alloy, nickel-titanium-based alloys that can be generally used in the medical field can be used in the same manner. Examples thereof include a nickel-titanium alloy and a nickel-titanium-copper alloy obtained by adding copper to a nickel-titanium alloy. Of these, nickel-titanium alloy (Nitinol) containing about 50 wt% to about 60 wt% nickel and the balance being titanium is preferable from the viewpoint of in-vivo use results and superelastic characteristics.
　［第２の金属材料］
　第２の金属材料は、前記第１の金属材料より貴な金属であり、連結部の少なくとも一部を形成する。第２の金属材料は、第１の金属材料と同様に、通常医療分野においてステントとして使用されるものと同様の金属が使用でき、具体的には、金、白金、銀、パラジウムおよびそれらを主成分とする合金のいずれかであると好ましく、特には金、白金およびそれらを主成分とする合金のいずれかであると好ましい。特に、金、白金は高い延性を持つため、留置完了前に破断する恐れが少ない。また、その柔軟さ（低弾性、高延性）により、留置後の血管形状に柔軟に追従し優れたコンフォーマビリティを発揮するという効果を有する。なお、本明細書において「主成分」とは全成分のうち質量％が最も多いものを意味する。 [Second metal material]
The second metal material is a noble metal than the first metal material and forms at least a part of the connecting portion. Similar to the first metal material, the second metal material can be the same metal as that usually used as a stent in the medical field. Specifically, gold, platinum, silver, palladium, and the like are mainly used. Any one of the alloys as the components is preferable, and in particular, any of gold, platinum, and an alloy containing them as the main component is preferable. In particular, since gold and platinum have high ductility, there is little risk of breakage before completion of indwelling. Further, due to its flexibility (low elasticity, high ductility), it has an effect of flexibly following the indwelling blood vessel shape and exhibiting excellent conformability. In the present specification, “main component” means a component having the largest mass% of all components.
　また、上記で列挙した第２の金属材料を用いれば第１の金属材料に対して比重が有意に高いため、高いＸ線不透過性を実現でき、Ｘ線透視下で良好に視認できるため、生体管腔内に安全に留置できることができる。本発明において、第２の金属材料の比重としては、好ましくは、１０ｇ／ｃｍ３以上であり、より好ましくは１２ｇ／ｃｍ３以上である。上限としては特に制限はないが、例えば、２３ｇ／ｃｍ３以下、あるいは２２ｇ／ｃｍ３以下である。 In addition, if the second metal material listed above is used, the specific gravity is significantly higher than that of the first metal material, so that high radiopacity can be realized and it can be seen well under X-ray fluoroscopy, It can be safely placed in the body lumen. In the present invention, the specific gravity of the second metal material is preferably 10 g / cm 3 or more, more preferably 12 g / cm 3 or more. There are no particular limitations on the upper limit, e.g., 23 g / cm 3 or less, or at 22 g / cm 3 or less.
　なお、第２の金属材料は、第１の金属材料より貴な金属であるように選択されればよいが、両者の関係は相対的なものであるので、例えば、上記で列挙した第２の金属材料から、異なる二種の金属材料を選択し、そのうち相対的に卑な金属材料であるものを第１の金属材料として使い、貴な金属材料であるもの第２の金属材料として使ってもよい。ただし比重が相対的に高いような金属材料を環状体を形成する線状構成要素として使うと硬くて脆い場合もあり、その観点においては上記の第１の金属材料で列挙したような金属材料を環状体を形成する線状構成要素として用いることが好ましい。 The second metal material may be selected to be a noble metal than the first metal material. However, since the relationship between the two metal materials is relative, for example, the second metal material listed above is used. Two different kinds of metal materials are selected from the metal materials, and a relatively base metal material is used as the first metal material, and a noble metal material is used as the second metal material. Good. However, when a metal material having a relatively high specific gravity is used as a linear component forming the annular body, it may be hard and brittle. In that respect, the metal materials listed in the first metal material are not suitable. It is preferably used as a linear component forming an annular body.
　ところで、本発明におけるステントの構造は、図１で示された形態に限定されず、線状構成要素により環状に形成された環状体が、軸方向に複数配列するとともに、隣り合う環状体が連結部により連結されたものであれば良い。また、ステントを構成する線材（すなわち、線状構成要素）の断面形状についても、矩形、円形、楕円形、其の他の多角形等が挙げられるが、それ以外の形状であってもよい。 By the way, the structure of the stent in the present invention is not limited to the form shown in FIG. 1, and a plurality of annular bodies formed annularly by linear components are arranged in the axial direction and adjacent annular bodies are connected. What is connected by the part should just be. Moreover, although the cross-sectional shape of the wire (that is, linear component) which comprises a stent also includes a rectangle, a circle, an ellipse, other polygons, etc., other shapes may be sufficient.
　また、上記で説明した、ステントの大きさは、特に制限されず、適用箇所に応じて適宜選択すればよい。拡張前（バルーンに装着された状態）におけるステントの外径は、０．３～５ｍｍ程度が好ましく、０．４～４．５ｍｍ程度がより好ましく、０．５～１．６ｍｍ程度が特に好ましい。また、ステントの長さもまた、特に制限されず、処置すべき疾患によって適宜選択できる。例えば、ステントの長さは、５～１００ｍｍ程度が好ましく、６～５０ｍｍ程度がより好ましい。 Further, the size of the stent described above is not particularly limited, and may be appropriately selected according to the application location. The outer diameter of the stent before expansion (when attached to the balloon) is preferably about 0.3 to 5 mm, more preferably about 0.4 to 4.5 mm, and particularly preferably about 0.5 to 1.6 mm. Further, the length of the stent is not particularly limited and can be appropriately selected depending on the disease to be treated. For example, the length of the stent is preferably about 5 to 100 mm, more preferably about 6 to 50 mm.
　または、ステントの長さは、１．５～４ｍｍ程度が好ましく、２～３ｍｍ程度がより好ましい場合もある。 Alternatively, the length of the stent is preferably about 1.5 to 4 mm, and more preferably about 2 to 3 mm.
　続いて、本発明のステントの製造方法の好ましい形態を説明する。本発明のステントは、第１の金属材料からなるステント部材と、第２の金属材料からなるステント部材とを、公知の固相接合の方法を適宜参照し、あるいは組み合わせることによって作製することができる。公知の固相接合の方法としては、（１）圧接（２）拡散接合（３）摩擦溶接（摩擦圧接）（４）超音波溶接などがある。このような公知の固相接合を適用して、第１の金属材料からなるステント部材と第２の金属材料からなるステント部材の所望の部位を固相接合し、接合体（ロッド）を作製する。このようにして作製したロッドを切削加工により中心部を繰り抜き、パイプ形状にする。その後、第２の金属材料により形成されている部分が連結部に入るように位置あわせを行ってレーザー加工によりステントのパターンにカットし、さらに化学研磨、電解研磨を施しステントを作製することができる。 Subsequently, a preferable embodiment of the stent manufacturing method of the present invention will be described. The stent of the present invention can be produced by appropriately referring to or combining a known solid-phase joining method with a stent member made of the first metal material and a stent member made of the second metal material. . Known solid phase bonding methods include (1) pressure welding (2) diffusion bonding (3) friction welding (friction welding) (4) ultrasonic welding and the like. By applying such known solid-phase bonding, a desired portion of the stent member made of the first metal material and the stent member made of the second metal material are solid-phase bonded to produce a bonded body (rod). . The rod thus produced is cut out at the center to form a pipe. After that, alignment is performed so that the portion formed of the second metal material enters the connecting portion, and it is cut into a stent pattern by laser processing, and further, chemical polishing and electrolytic polishing can be performed to produce a stent. .
　なお、拡散接合する際の条件にも特に制限はなく、第１の金属材料と、第２の金属材料との種類に応じて適切選択することができる。 In addition, there is no restriction | limiting in particular also in the conditions at the time of diffusion joining, According to the kind of 1st metal material and 2nd metal material, it can select suitably.
　本発明の効果を、以下の参考例・実施例を用いて説明する。 The effect of the present invention will be described using the following reference examples and examples.
　＜参考例１＞
　市販のステント（Ｎｏｂｏｒｉ（登録商標）、テルモ株式会社製）を構成する金属であるＳＳ３１６Ｌ、市販のステント（Ｋａｎａｍｅ（商標）、テルモ株式会社製）を構成する金属であるＬ６０５（Ｃｏ－Ｃｒ合金）および金について、自然浸漬電位（ｍＶ）を測定した。その結果を下記表１に示す。この場合、ＳＳ３１６Ｌ及びＬ６０５が、第１の金属材料に相当し、金が第２の金属材料に相当する。結果を表１に示す。 <Reference Example 1>
SS316L which is a metal constituting a commercially available stent (Nobori (registered trademark), manufactured by Terumo Corporation), L605 (Co—Cr alloy) which is a metal which constitutes a commercially available stent (Kaname (trademark), manufactured by Terumo Corporation) The natural immersion potential (mV) was measured for gold and gold. The results are shown in Table 1 below. In this case, SS316L and L605 correspond to the first metal material, and gold corresponds to the second metal material. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　上記表１より、金（Ａｕ）の、ＳＳ３１６ＬまたはＬ６０５に対する自然浸漬電位の差が有意に大きく、ガルバニック腐食を起こして、本発明の連結部を切断することが期待される。 From Table 1 above, it is expected that the difference in natural immersion potential of gold (Au) with respect to SS316L or L605 is significantly large, causing galvanic corrosion and cutting the connecting portion of the present invention.
　＜参考例２＞
　図５の装置を用いて、下記方法によって、ガルバニック電流を測定した。結果を図６に示す。すなわち、第２の金属材料である、試料（金）を適当なサイズ（２ｃｍ×２ｃｍ）に切断した。切断後、試料を耐水研磨紙を用いて流水下で研磨した。この際、研磨紙は、目の粗いもの（１５０番）から始め、最終的に６００番まで使用した。研磨後、試料を蒸留水中で５分間超音波洗浄した。洗浄後、試料に導線をクリップにより接続した。次に、試料が１平方ｃｍのみ露出するように、導線との接続部などを含めてシール剤で被覆した。これを試料極（電極Ｓ２）として使用した。同様にして、市販のステント（Ｋａｎａｍｅ（商標）、テルモ株式会社製）を構成する金属であるＬ６０５（Ｃｏ－Ｃｒ合金）を第１の金属材料として用い、上記と同様にして、導線接続、シール剤での被覆を行い、これを対極（電極Ｓ１）として使用した。被覆後、２４時間以内に、以下の評価に供した。この際、参照極（標準電極）として、飽和カロメル電極（saturated calomel electrode, CE）Ｓ３を使用し、参照極Ｓ３と電極Ｓ１、Ｓ２との間にエレクトロメーター（図５中の「Ｅ」）を設置した。ＰＢＳ溶液（組成：８．０ｇ／Ｌ　ＮａＣｌ、０．２ｇ／Ｌ　ＫＣｌ、１．１５ｇ／Ｌ　Ｎａ２ＨＰＯ４、０．２ｇ／Ｌ　ＫＨ２ＰＯ４、ｐＨ　７．２～７．６）を入れたセルＤを恒温浴槽（図示せず）内に入れ、ＰＢＳ溶液の温度を３７℃に保持した。ＰＢＳ溶液に高純度窒素ガスを３０分以上バブリングした。その後、上記で調製した電極Ｓ１、Ｓ２をＰＢＳ溶液中に浸漬させた。対極（電極Ｓ１）及び試料極（電極Ｓ２）間に流れる電流を無抵抗電流計（図５中の「Ｉ」）で測定した。なお、この際の測定温度は、３７℃に調節した。 <Reference Example 2>
The galvanic current was measured by the following method using the apparatus of FIG. The results are shown in FIG. That is, the sample (gold) that is the second metal material was cut into an appropriate size (2 cm × 2 cm). After cutting, the sample was polished under running water using water-resistant abrasive paper. At this time, the abrasive paper started from the coarser one (No. 150) and finally used up to No. 600. After polishing, the sample was ultrasonically cleaned in distilled water for 5 minutes. After washing, the lead wire was connected to the sample by a clip. Next, the sample was covered with a sealing agent including the connecting portion with the conductor so that only 1 cm 2 was exposed. This was used as a sample electrode (electrode S2). Similarly, L605 (Co—Cr alloy), which is a metal constituting a commercially available stent (Kaname (trademark), manufactured by Terumo Corporation), is used as the first metal material. Coating with an agent was performed, and this was used as a counter electrode (electrode S1). The following evaluations were made within 24 hours after coating. At this time, a saturated calomel electrode (CE) S3 is used as a reference electrode (standard electrode), and an electrometer (“E” in FIG. 5) is provided between the reference electrode S3 and the electrodes S1 and S2. installed. PBS solution (composition: 8.0 g / L NaCl, 0.2 g / L KCl, 1.15 g / L Na 2 HPO 4 , 0.2 g / L KH 2 PO 4 , pH 7.2 to 7.6) The cell D was placed in a thermostatic bath (not shown), and the temperature of the PBS solution was maintained at 37 ° C. High purity nitrogen gas was bubbled into the PBS solution for 30 minutes or more. Thereafter, the electrodes S1 and S2 prepared above were immersed in a PBS solution. The current flowing between the counter electrode (electrode S1) and the sample electrode (electrode S2) was measured with a non-resistance ammeter (“I” in FIG. 5). The measurement temperature at this time was adjusted to 37 ° C.
　図６に示されるように、第２の金属材料である金は、第１の金属材料であるＬ６０５に対してガルバニック電流（局部電流）が生じ、腐食していることが分かる。 As shown in FIG. 6, it can be seen that gold, which is the second metal material, is corroded due to a galvanic current (local current) generated with respect to L605, which is the first metal material.
　＜実施例１＞
　直径（外径）２ｍｍ、長さ０．９ｍｍ、肉厚８０μｍのＬ６０５パイプと、直径（外径）２ｍｍ、長さ０．１ｍｍ、肉厚８０μｍのＡｕパイプを中心軸が揃うようにセラミック製の治具にセットする。 <Example 1>
The L605 pipe with a diameter (outer diameter) of 2 mm, a length of 0.9 mm, and a wall thickness of 80 μm, and an Au pipe with a diameter (outer diameter) of 2 mm, a length of 0.1 mm, and a wall thickness of 80 μm are made of ceramic so that the central axes are aligned. Set on the jig.
　これを各１４回繰り返し、最後に直径２ｍｍ、長さ５０ｍｍ、肉厚８０μｍのＬ６０５パイプをセラミック製治具にセットする。なお、各１４回繰り返すことため、ステントの長さは１４ｍｍとなる。 This is repeated 14 times, and finally an L605 pipe having a diameter of 2 mm, a length of 50 mm, and a wall thickness of 80 μm is set in a ceramic jig. In addition, since it repeats 14 times each, the length of a stent will be 14 mm.
　これらのパイプの集合体の両側を、セラミック製のロッドで固定することにより各パイプを密着させる。これを治具ごとＡｒガス雰囲気の熱処理炉内で９５０℃、６時間処理し各パイプを拡散接合させる。治具からパイプを取出し、レーザカットする際、パイプの片端をつかんでパイプを回転させたり、軸上に移動させたりするが、そのつかみ代の部分とするため、若干長い、長さ５０ｍｍのＬ６０５の部分をレーザーカット機のチャック部で固定する。次にレーザーカット機のステージにより、Ａｕパイプ部がステント連結部にくるように正確に位置決めし、レーザーカットによりステントパターンを形成する。これを化学研磨処理、電解研磨処理を施しステントを作製する。このように作製することで、ステントの拡張タイプとしてバルーン拡張型ステントとなり、また、形状としては、パイプ（管状体）に開口部を設けたものとなる。 ¡The pipes are brought into close contact with each other by fixing both sides of these pipe assemblies with ceramic rods. This is treated together with a jig in a heat treatment furnace in an Ar gas atmosphere at 950 ° C. for 6 hours, and each pipe is diffusion bonded. When removing the pipe from the jig and laser cutting, the pipe is rotated by holding one end of the pipe or moved on the shaft. Is fixed with the chuck part of the laser cutting machine. Next, with the stage of the laser cutting machine, the Au pipe portion is accurately positioned so as to come to the stent connecting portion, and a stent pattern is formed by laser cutting. This is subjected to chemical polishing treatment and electrolytic polishing treatment to produce a stent. By manufacturing in this way, it becomes a balloon-expandable stent as an expansion type of the stent, and as a shape, an opening is provided in a pipe (tubular body).
　なお、本出願は、２０１３年４月５日に出願された日本特許出願番号２０１３－０７９３３１号に基づいており、その開示内容は、参照され、全体として、組み入れられている。 Note that this application is based on Japanese Patent Application No. 2013-079331 filed on April 5, 2013, the disclosure of which is incorporated by reference in its entirety.
　　１　　ステント、
　　２　　線状構成要素、
　　Ａ　　略菱形の要素、
　　Ｂ　　環状ユニットＢ
　　Ｃ　　連結部、
　　Ｃ１　第１連結部、
　　Ｃ２　第２連結部、
　　４　　第１の金属材料、
　　５　　第２の金属材料、
　　Ｓ１　対極、
　　Ｓ２　試料極、
　　Ｓ３　参照極、
　　Ｄ　　セル、
　　Ｉ　　無抵抗電流計、
　　Ｅ　　エレクトロメーター。 1 stent,
2 linear components,
A A roughly diamond-shaped element,
B Ring unit B
C connecting part,
C1 first connecting part,
C2 second connecting part,
4 first metal material,
5 Second metal material,
S1 counter electrode,
S2 Sample electrode,
S3 reference electrode,
D cell,
I Non-resistance ammeter,
E Electrometer.

Claims (5)

  1. 　線状構成要素により構成され、生体内への留置操作時に変形することにより生体管腔に密着するガルバニック腐食ステントであって、
    　前記ステントは、前記線状構成要素により環状に形成された環状体が、軸方向に複数配列するとともに、隣り合う環状体が連結部により連結されたものであり、
    　前記環状体は、第１の金属材料により形成されており、
    　前記連結部の少なくとも一部は、前記第１の金属材料より貴な第２の金属材料により形成され、
    　生体内に留置された後、ガルバニック腐食によって前記連結部が切断される、ガルバニック腐食ステント。     A galvanic corroded stent that is composed of linear components and adheres to a living body lumen by being deformed during indwelling operation in a living body,
    The stent has a plurality of annular bodies formed in an annular shape by the linear constituent elements and is arranged in the axial direction, and adjacent annular bodies are connected by a connecting portion,
    The annular body is formed of a first metal material,
    At least a part of the connecting portion is formed of a second metal material that is noble than the first metal material,
    A galvanic corrosion stent in which the connecting portion is cut by galvanic corrosion after being placed in a living body.
  2. 　前記第１の金属材料と、前記第２の金属材料の自然浸漬電位の差が２００ｍＶを超えて１０００ｍＶ以下である、請求項１に記載のガルバニック腐食ステント。 The galvanic corrosion stent according to claim 1, wherein a difference in natural immersion potential between the first metal material and the second metal material is more than 200 mV and 1000 mV or less.
  3. 　前記第２の金属材料が、金、白金、銀、パラジウムおよびそれらを主成分とする合金のいずれかである、請求項１または２に記載のガルバニック腐食ステント。 The galvanic corrosion stent according to claim 1 or 2, wherein the second metal material is any one of gold, platinum, silver, palladium, and an alloy containing them as a main component.
  4. 　前記第１の金属材料が、ステンレス鋼、Ｃｏ－Ｃｒ系合金、Ｎｉ－Ｔｉ系合金のいずれかである、請求項１～３のいずれか１項に記載のガルバニック腐食ステント。 The galvanic corrosion stent according to any one of claims 1 to 3, wherein the first metal material is any one of stainless steel, a Co-Cr alloy, and a Ni-Ti alloy.
  5. 　前記環状体が、波状環状体である、請求項１～４のいずれか１項に記載のガルバニック腐食ステント。 The galvanic corrosion stent according to any one of claims 1 to 4, wherein the annular body is a wavy annular body.
PCT/JP2014/057906 2013-04-05 2014-03-20 Galvanic corrosion stent WO2014162903A1 (en)

Applications Claiming Priority (2)

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JP2013079331A JP2016105750A (en) 2013-04-05 2013-04-05 Galvanic corrosion stent

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009502307A (en) * 2005-07-25 2009-01-29 インヴァテック エス．アール．エル． Lumen prosthesis with bioabsorbable site
JP2009082243A (en) * 2007-09-27 2009-04-23 Terumo Corp In-vivo indwelling stent and living organ dilator
JP2009537286A (en) * 2006-05-19 2009-10-29 メドトロニック ヴァスキュラー インコーポレイテッド Electrolytic corrosion method and apparatus for securing a stent graft
JP2009538183A (en) * 2006-05-22 2009-11-05 アボット カーディオヴァスキュラー システムズ インコーポレイテッド Degradable medical device
WO2009152153A2 (en) * 2008-06-10 2009-12-17 Boston Scientific Scimed, Inc. Bioerodible endoprosthesis

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009502307A (en) * 2005-07-25 2009-01-29 インヴァテック エス．アール．エル． Lumen prosthesis with bioabsorbable site
JP2009537286A (en) * 2006-05-19 2009-10-29 メドトロニック ヴァスキュラー インコーポレイテッド Electrolytic corrosion method and apparatus for securing a stent graft
JP2009538183A (en) * 2006-05-22 2009-11-05 アボット カーディオヴァスキュラー システムズ インコーポレイテッド Degradable medical device
JP2009082243A (en) * 2007-09-27 2009-04-23 Terumo Corp In-vivo indwelling stent and living organ dilator
WO2009152153A2 (en) * 2008-06-10 2009-12-17 Boston Scientific Scimed, Inc. Bioerodible endoprosthesis

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