Classifications

• • 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
• • 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
  • A61F2/92—Stents in the form of a rolled-up sheet expanding after insertion into the vessel, e.g. with a spiral shape in cross-section
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/30—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core
  • B29C70/32—Shaping by lay-up, i.e. applying fibres, tape or broadsheet on a mould, former or core; Shaping by spray-up, i.e. spraying of fibres on a mould, former or core on a rotating mould, former or core
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/54—Component parts, details or accessories; Auxiliary operations, e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
  • B29C70/545—Perforating, cutting or machining during or after moulding
• • 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
  • A61F2230/00—Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2230/0063—Three-dimensional shapes
  • A61F2230/0091—Three-dimensional shapes helically-coiled or spirally-coiled, i.e. having a 2-D spiral cross-section
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2793/00—Shaping techniques involving a cutting or machining operation
  • B29C2793/0045—Perforating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C53/00—Shaping by bending, folding, twisting, straightening or flattening; Apparatus therefor
  • B29C53/56—Winding and joining, e.g. winding spirally
  • B29C53/562—Winding and joining, e.g. winding spirally spirally

Definitions

• the invention relates to a method for making an extensible stent which is to be brought into a form- retaining state by curing.
• Vasculair stents for locally reinforcing a body vessel, to be introduced by means of a catheter are brought into their final configuration by means of an extensible element at the distal end of this catheter whereafter irridiation with UV radiation initiates the curing of the plastics material are known from the prior art. Mentioned are the patent publications US-5.344.444 , US-5.464.419 , EP- 0 521 573 Bl en EP-0 617 930, all haviang the same inventor as the present one.
• the invention aims to provide such a ethode.
• the invention proposes a method for making an extensible stent which is brought in a form retaining state with predetermined final configuration by curing, in which one starts from a template with an outer configuration corresponding with the desired final configuration, winds this with sheet-shaped material made from coherent fibers which is either before or after the winding soaked with a plastics with a controlled initiated curing.
• This plastics can be dissolved in a solvent whichthereafter is evaporated controllable by heating.
• the method according to the invention is excellently suited to provide thereon a therapeutic active for a radiation emitting substance leads to the advantage that it is possible to implant it into a patient directly after the determination of shape and configuration of such a stent, so that the treatment can be started without any delay.
• a sheet-shaped base material with metallic reinforcing fibers distributed therein With these simple measures which can be integrated simply in the fabrication process of the base material an increased strength of the material is obtained so that for a particular use it can have smaller dimensions, particularly a smaller thickness, in combination with a certain opaqueness for X-ray radiation so that not only the positioning but also the detection of a stent made from this material at a later moment becomes very easy.
• Length, diameter and configuration of the fibers will, in a certain practical embodiment, be adapted to the use one has in view. Preferred embodiments are given in the claims 9 and 10.
• the starting material for the fibers can be made radioactive by introducing a radio-active isotope in the melt thereof.
• a radio-active isotope in the melt thereof.
• the sheet-shaped starting material which comprises the fibers is preferrably made in the way as described in the claims 19-21.
• the claimed exclusive rights also include a stent such as is subject of the claims 22-26.
• the invention is elucidated on the hand of a drawing.
• fig. 1 schematically the use of a template in the method according to the invention
• fig. 2 in cross-section a preferred embodiment of a stent, obtained therewith
• fig. 3 the use of a template to execute the method according to the invention in combination with the provision of openings in the surface of the stent obtained therewith
• fig. 4 a side view of a stent, obtained in this way
• fig. 5 a side view of a template and the stent formed thereon, having a tapering configuration
• FIG. 6 a side view of a template with a stent made thereon in a configuration in which the ends of the stent have a greater diameter than the middle part thereof;
• fig. 7 schematically and in top view sheet-shaped material to be used in the method according to the invention;
• fig. 8 schematically and in perspective a stent made from this material;
• fig. 9 schematically and in top view sheet-shaped material to be used in the method according to the invention according to a second embodiment;
• fig. 10 schematically and in perspective view another embodiment of a stent obtained by using this material;
• fig. 13 a fourth embodiment of the sheet-shaped starting material according to the invention; and fig.
• the material After winding such a length of material on the template 2 that the wound cylinder 5 has obtained the desired thickness the material is cut-off and thereafter soaked in a plastics, which can be dissolved in a solvent of the kind known as such, the curing ofo the plastics can be initiated controllably by irradiation with UV-radiation.
• a fiber material which is soaked in such a plastics before it is wound, but handling thereof is somewhat more difficult.
• this stent of which the outer surface is still somewhat sticky, can be rolled in a therapeutic substance (aspirin, heparin, cocain) in powder form, which adheres to the outer surface and can easily be provided thereon in a controlled quantity. Controlled powdering is also possible.
• a therapeutic substance aspirin, heparin, cocain
• Controlled powdering is also possible.
• the ends of a stent are more flexible than the middle part and according to the invention this can be obtained very simply by chosing a higher concentration of the plastics material in the end zones, indicated in fig. 2 with 6a and 6b, than in the middle zone 8.
• a substance with a therapeutic action or a substance emitting radio-active radiation is provided not over the entire surface of the stent but only in a certain part thereof.
• the method of the invention makes it easy to coat the, still sticky, outer surface of the stent with a substance with therapeutic action, not equally, but only selectively on certain surface parts.
• the invention also gives the possibility to form openings on certain preferred places in the stent, said openings being filled with a substance with therapeutic action later-on. 5
• fig. 3 shows, use a template 10 in which the stent 12, wound thereon, is pierced by pins, placed in rings, as indicated by 14, 16 en 18. After curing of the stent and the removal of the pins the stent 20 results within its body three rings of openings 14', 16', 18', corresponding with the rings of pins 14, 16 and 18.
• FIG. 5 shows a somewhat tapering template 22 of which the left hand end 24a has a smaller diameter than the right hand end 24b; corresponding therewith the stent 26, obtained with this template, is also tapering; the left hand end 28a has a smaller diameter than the right hand end 28b.
• This stent can be removed easily from the template 22.
• FIG. 6 shows in side view such an embodiment of the method according to the invention: the template 30, as used, has ends 32a, 32b with a greater diameter than the middle part and corresponding therewith the stent 34, formed thereon, has ends 36a, 36b with a greater diameter than the middle part 38.
• metallic reinforcing fibers into the sheet-shaped starting material.
• These fibers are preferably made from titanium, generally from a "biocompatible" material . This introducing can be done during the grinding of the fibers or also during the intensive mixing of the pulp.
• the length and the diameter of the fibers to be added can be chosen in dependance on the final use one has in mind.
• the fibers can be supplied individually and incoherently but it is also possible to introduce them more or less coherently into the pulp, as will be described later on.
• As a value for the minimum diameter to be used one thinks of 5 ⁇ m and as minimum length 1-2 mm, although the 6 dimensions are certainly not restrictive and particularly the minimum dimensions are only set by the possibility of handling the fibers.
• the weight percentage of the fibers can be chosen independant from the aim one has in mind: a weight percentage of 10-20% is possible. Other values are also possible.
• Fig. 7 shows a part of sheet material 42 with equally distributed metallic fibers 44 therein, which are, of course, shown only schematically.
• the sheet 42 is cut up along the perpendicular crossing vertical cutting lines 46a, 46b, 46c to individual sheets 4a, from which the stent 50, shown in perspective view in fig. 8, is made.
• the fibers are not distributed equally but according to a pattern of mutual parallel lines which include an angle with the boundaries of the sheet 44, such as shown in fig. 9, according to which the sheet 42 is provided with a pattern of strips 54 in which metallic fibers are embedded in the starting material.
• a stent as shown in fig. 10 and indicated therein with reference numeral 56, made from such a sheet 54 has strips 60 which run obliquely over the outer surface 58 and in which the metallic fibers, which give the stent 56 its strength, are embedded in the material.
• the sleeve is irradiated from within with UV radiation and practically the whole inner surface will then be irradiated equally. 7
• the stent When the fibers are prepared in such a way that they emit radio-active radiation the stent also has a therapeutic action.
• a stent in the way as shown schematically and in perspective view in fig. 11: a sleeve 62 from normal fiber material which has none or only a very small percentage of metallic fibers supports, on the outer surface 64 thereof, a helically wound strip 66 which is made of sheet material, soaked with curing plastics and having therein a certain concentration metallic fibers.
• a sleeve 62 from normal fiber material which has none or only a very small percentage of metallic fibers supports, on the outer surface 64 thereof, a helically wound strip 66 which is made of sheet material, soaked with curing plastics and having therein a certain concentration metallic fibers.
• the irradiation of the curing plastics will take place starting from the center of the core so that the base layer 64 will cure swiftly and uniformly; however after this layer 24 sufficient UV radiation reaches the strip 26 to initiate the curing thereof.
• This embodiment has the advantage that one can choose the composition of the plastics present in the strips 66 in such a way that the curing of the basic core 64 and the strips 66 occurs equally fast.
• the aspect discussed above according to which the fibers are distributed strip-like in the basic material can also be realised in the way as shown in fig. 12.
• the fibers will be made generally by drawing wire-shaped starting material and in the known manner they are then available in bundles; from such a bundle of fibers smaller bundles are made which are embedded with predetermined mutual distances in the pulp material.
• Fig. 12 shows a part of a pulp bed indicated with reference numeral 90 ; with predetermined mutual distances d fiber bundles 92 are embedded therein. Finally one obtains a starting material which is reinforced in a strip-like manner and from which stents having the configuration according to fig. 4 can be made.
• Fig. 13 shows a fiber material 80 having therein elongate fibers 82 which are all directed in the same direction indicated by the arrow 84.
• a part 80a is separated therefrom, from which part finally a cylindrical stent 86 according to fig. 8 is made, all fibers 88 therein will be oriented in the circumferential direction. In this way this element has an increased radial strength.
• this stent can be coated with the commercially available 8
• chromeflex ® , whereafter the whole is baked at a suitable temperature. This results in a biocompatible outer surface so that the material can be used without problems in a body vessel.

Landscapes

• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Vascular Medicine (AREA)
• Animal Behavior & Ethology (AREA)
• Composite Materials (AREA)
• Cardiology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Transplantation (AREA)
• Heart & Thoracic Surgery (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mechanical Engineering (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Materials For Medical Uses (AREA)
• Media Introduction/Drainage Providing Device (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Prostheses (AREA)
• Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19766390

Family Applications (1)

Country Status (6)

Cited By (3)

Citations (9)

Family Cites Families (3)

• 1998
  • 1998-01-22 NL NL1008093A patent/NL1008093C2/nl not_active IP Right Cessation
• 1999
  • 1999-01-20 AU AU19865/99A patent/AU1986599A/en not_active Abandoned
  • 1999-01-20 EP EP99900719A patent/EP1049419B1/en not_active Expired - Lifetime
  • 1999-01-20 JP JP2000528233A patent/JP2002500921A/ja active Pending
  • 1999-01-20 WO PCT/NL1999/000035 patent/WO1999037243A1/en not_active Ceased
  • 1999-01-20 DE DE69926603T patent/DE69926603T2/de not_active Expired - Lifetime

Patent Citations (9)

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