JP5657943B2 - Manufacturing method of stent delivery catheter - Google Patents

Description

  The present invention relates to a method for manufacturing a reduced diameter stent and a method for manufacturing a stent delivery catheter.

  Stents generally treat a variety of diseases caused by stenosis or occlusion of blood vessels or other in vivo lumens. Specifically, a stent is a medical device that is placed in order to expand a stenosis or occlusion site and maintain its lumen size.

  Examples of the stent include a coil type made of a single linear metal or polymer material, a type in which a metal tube is cut out by a laser, a type in which a linear member is assembled by welding with a laser, or There are types made by weaving multiple linear metals.

  These stents are expanded by a balloon mounted with the stent (balloon expandable type), and are expanded by removing members that suppress expansion from the outside (self-expandable). Type).

  For example, the self-expandable type is generally used in the vicinity of the distal end of an intravascular catheter and covered with a sheath or the like. More specifically, the catheter is advanced to the treatment site in the body lumen of the patient, the sheath or the like is removed at the treatment site, and the stent is placed by self-expansion along with this. In recent years, these stents have been frequently used for ureteral, bile duct, or lower limb arthroplasty.

  When a self-expandable stent is delivered to a target lesion, the stent is generally inserted into a delivery catheter (note that a delivery catheter equipped with a stent is referred to as a stent delivery catheter). The delivery catheter itself may be referred to as a stent delivery catheter).

  In the case of such insertion, the stent is contracted (crimped) to be equal to or smaller than the inner diameter of the outer tube of the delivery catheter. And such a stent is separated from an outer tube, and is arrange | positioned in a lesioned part after conveying to a lesioned part with a delivery catheter.

  Generally, a stent crimping apparatus is used for crimping a stent. Furthermore, the distal end of the delivery catheter is brought into contact with the crimping head of the stent crimping device (the portion that reduces the diameter of the stent), and the stent is inserted into the lumen of the delivery catheter.

  Patent document 1 is mentioned as an example of the crimping of a stent. According to Patent Document 1, since the stent is inserted into the elastic tube and crimped, the stent is crimped by applying a force in the longitudinal direction and the radial direction of the stent.

  Patent document 2 is mentioned as an example of a stent delivery catheter (stent delivery system). According to Patent Document 2, the stent is inserted into the inner sheath, and the inner sheath is inserted into the outer sheath. In this way, when the stent is deployed or filled into the delivery catheter, friction generated on the stent can be suppressed.

  Patent Document 3 is also an example of a stent delivery catheter (device for transporting a stent). According to Patent Document 3, the stent and the stent mounting member are moved or slid in the axial direction near the proximal end portion of the outer tubular member, and the stent is radially compressed in the stent deployment region. The

Special table 2008-538940 gazette Special table 2008-529719 gazette Special table 2009-537277

  However, in the technique of Patent Document 1, when the stent is crimped, the extension of the stent in the longitudinal direction and the overlap of the struts are not prevented (in short, the stent is crimped unevenly).

  Further, even the techniques of Patent Documents 2 and 3 cannot prevent the stent from being crimped unevenly.

  If the stent is crimped non-uniformly, the struts included in the stent overlap each other. Therefore, when the stent is inserted into the lumen of the delivery catheter, the force in the longitudinal direction of the stent is hardly transmitted. Then, the strut is distorted, and the strut is buckled. This would make it difficult to insert the stent into the lumen of the delivery catheter.

  The present invention has been made to solve the above problems. And the objective is to provide the manufacturing method of the reduced diameter stent etc. which are easy to mount | wear with a delivery catheter.

The manufacturing method of a stent delivery catheter in which a reduced diameter stent is attached to a delivery catheter includes the following steps.
That is, a step of placing the stent in a diameter reducing device having a crimping head for reducing the diameter of the stent by pressing the stent from the outside;
Including a core rod and a rod having a larger outer diameter than the core rod, and inserting the core rod in a mandrel that is connected so as to be in a series and arranged coaxially inside the stent;
Reducing the diameter of the stent from a first outer diameter to a second outer diameter;
A step of arranging a housing cavity of a crimping head for holding a stent in a reduced diameter state and a lumen in a delivery catheter in a coaxial manner ;
By making the mandrel enter the stent in the storage cavity, the peripheral edge of the stent reduced to the second outer diameter is larger than the inner diameter of the stent reduced to the second outer diameter and smaller than the outer diameter. Pushing at the periphery of a bar with a large outer diameter and moving it to the lumen of the delivery catheter;
Is included.

Moreover, when the delivery catheter has inserted the inner tube which attached the pusher marker in the position away from the front-end | tip in the outer tube which has a lumen | bore, it is preferable that the core rod in a mandrel is hollow .

Moreover, it is preferable that the bar in the mandrel is hollow .

In the step of reducing the diameter of the stent from the first outer diameter to the second outer diameter, the third outer diameter, which is an intermediate outer diameter between the first outer diameter and the second outer diameter, is used. The step of reducing the diameter of the stent is preferably included at least once .

In addition, it is preferable to cool the stent while maintaining the reduced diameter state of the stent .

The stent is preferably a self-expandable stent .

By the way, the mandrel may be of a type including a core bar excluding the bar material. Moreover, the core rod in the mandrel can be solid, and the bar in the mandrel can be solid .

Also includes a method for producing a reduced diameter stent, in the manufacturing method of the stent delivery catheter is fitted with a reduced diameter stent delivery catheter, it may also be is as follows.

For example, when the mandrel is a type including a core bar excluding the bar material , the mandrel is reduced to the second outer diameter by a step of pulling out the core bar from the stent maintained at the second outer diameter and another bar material. Pushing the radiused stent and moving it to a delivery catheter may be included .

Also includes a method for producing a reduced diameter stent, in the manufacturing method of the stent delivery catheter is fitted with a reduced diameter stent delivery catheter, it may also be is as follows.

For example, in the case where the mandrel includes a core bar excluding the bar, the stent is larger than the outer diameter of the core bar and is reduced to the second outer diameter while the core bar is inserted into the stent. A step of pushing the stent reduced in diameter to the second outer diameter with another hollow bar having an inner diameter larger than the inner diameter and moving it to the delivery catheter may be included.

  According to the present invention, a reduced diameter stent that can be easily attached to a delivery catheter is manufactured.

Then, (A)-(H) is explanatory drawing which shows the manufacturing process of a reduced diameter stent, and the manufacturing process of the stent delivery catheter which mounts the reduced diameter stent. Then, (A)-(G) is explanatory drawing which shows the manufacturing process of a reduced diameter stent, and the manufacturing process of the stent delivery catheter which mounts the reduced diameter stent. FIG. 3 is a cross-sectional view of a stent delivery catheter. FIG. 3 is a perspective view of a stent. FIG. 3 is a cross-sectional view of a stent delivery catheter. Then, (A)-(C) are explanatory drawings which show the manufacturing process of the stent delivery catheter which mounts | wears with a reduced diameter stent. Then, (A)-(G) is explanatory drawing which shows the manufacturing process of a reduced diameter stent, and the manufacturing process of the stent delivery catheter which mounts the reduced diameter stent.

[Embodiment 1]
The following describes one embodiment with reference to the drawings. For convenience, hatching, member codes, and the like may be omitted, but in such a case, other drawings are referred to. Moreover, even if it is not sectional drawing, hatching may be attached | subjected.

  FIG. 3 shows an example of a stent delivery catheter 69. The stent delivery catheter 69 is used to transport the stent 29 to a lesioned portion (stenosis portion) of a blood vessel, and is elongated and flexible so that it can be inserted into a lumen (from the stent delivery catheter 69, The one from which the stent 29 is removed may be referred to as a delivery catheter or may be referred to as a stent delivery catheter 69).

  The stent delivery catheter 69 includes a stent 29, an outer shaft 39, and an inner shaft 49 (in other words, the stent delivery catheter 69 includes a stent 29 and a delivery catheter having the outer shaft 39 and the inner shaft 49. ).

  As shown in FIG. 4, the stent 29 is formed by an annular substantially corrugated component [annular element] 22 continuing in an axial direction as one direction, and the substantially corrugated component 22 is formed by a strut 21 that extends. It is formed by connecting

  In the stent 29 as shown in FIG. 4, the outer diameter OD and the axial length LD are appropriately selected according to the inner diameter and length of the lesioned lumen, depending on the treatment target lumen. Different. For example, in the superficial femoral artery stent 29, the outer diameter OD is set to about 6.0 mm to 10.0 mm, and the axial length LD is set to about 30 mm to 200 mm.

  The stent 29 is formed, for example, by subjecting a nickel-titanium alloy pipe to laser cutting and expanding the diameter and heat-treating (the outer diameter of the expanded stent 29 is the first diameter). Called outer diameter).

  The outer shaft 39 includes an outer tube 31 that houses the stent 29 in a reduced diameter state (a part of the outer tube 31 that houses the stent 29 may be referred to as a stent holding portion). The stent 29 is a self-expandable stent that expands and treats a stenosis of a blood vessel. When the restriction by the lumen 32 of the outer tube 31 is released, the inner diameter of the stent 29 is the outer diameter of the outer tube 31. The diameter is expanded as described above, and the outer diameter after the expansion is determined.

  Further, the outer tube 31 is a member having flexibility enough to follow a lumen (blood vessel or the like) to be inserted, kink resistance, and a tensile strength that does not extend when the stent delivery catheter 69 is pulled during the procedure. Formed with.

  Further, when the outer tube 31 is moved, the inner layer of the outer tube 31 reduces the movement resistance (sliding resistance) with the stent 29 in contact with the inner peripheral surface of the layer, and the outer tube 31 It has a smoothness so that it can be easily moved.

  From the viewpoint of satisfying the above characteristics, the outer tube 31 has an outer layer (outer layer tube) 31T and an inner layer (inner layer tube) 31N formed of a resin material, and a metal wire between the outer layer 31T and the inner layer 31N. This layer (reinforcing layer) 31M is preferably formed of a three-layer resin-metal composite tube embedded therein.

  The outer layer 31T is a layer that covers the reinforcing layer 31M, and has a thickness of about 50 to 120 μm, for example. Examples of the material of the outer layer 31T include various elastomers such as polyamide elastomer, polyester elastomer, polyurethane elastomer, polystyrene elastomer, fluorine elastomer, silicone rubber, latex rubber, or a combination of two or more thereof. It is done.

  Examples of polyamide elastomers include nylon 6, nylon 64, nylon 66, nylon 610, nylon 612, nylon 46, nylon 9, nylon 11, nylon 12, N-alkoxymethyl modified nylon, hexamethylenediamine-isophthalic acid. Examples thereof include block copolymers in which various aliphatic or aromatic polyamides such as polymers or metaxyloyldiamine-adipic acid condensation polymers are used as hard segments, and polymers such as polyesters and polyethers are used as soft segments. .

  In addition, a polymer alloy (polymer blend, graft polymerization, random polymerization, etc.) of the above-mentioned polyamide and a flexible resin, or the above-mentioned polyamide softened with a plasticizer or the like, The concept including these mixtures is polyamide elastomer.

  The polyester elastomer is typically a block copolymer of a saturated polyester such as polyethylene terephthalate or polybutylene terephthalate and a polyether or polyester. In addition, these polymer alloys and saturated polyesters can be softened with a plasticizer or the like. It is a concept including a mixture of these, and a mixture thereof.

  From the viewpoint of processability and flexibility, an example of an excellent polyamide elastomer is Pebax or Rilsan manufactured by ARKEMA.

  The reinforcing layer 31M is a layer that is covered with the outer layer 31T, and is a layer that includes at least one of a synthetic resin strand and a metal strand (in short, the reinforcing layer 31M is made of only a synthetic resin strand. It may be formed only with a metal strand, or may be formed with a synthetic resin strand and a metal strand).

  In addition, the synthetic resin strand or the metal strand may be formed of the strand alone, or may be formed of an assembly strand (for example, a twisted or bundled strand).

  In addition, the metal strand is formed of at least one of a braided structure and a coil structure, and is preferably formed from one end to the other end in the length of the outer tube 31 (note that the operator The side close to the hand of the hand is called the proximal end, and the opposite side to the proximal end is called the distal end).

  In addition, as a material of a synthetic resin strand, for example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polymethylene terephthalate, polyolefins such as polyethylene and polypropylene, rigid polyvinyl chloride, polyamide, polyimide, polystyrene, thermoplastic polyurethane , Polycarbonate, ABS resin, acrylic resin, polymethyl methacrylate, polyacetal, polyarylate, polyoxymethylene, high tensile polyvinyl alcohol, fluororesin, polyvinylidene fluoride, polytetrafluoroethylene, saponified ethylene-vinyl acetate, polysulfone, polyethersulfone , Aromatic polyaramide represented by polyetherketone, polyphenylene oxide, polyphenylene sulfide, Kevlar , Polymer alloy containing any of these, carbon fibers, or glass fibers and the like.

  In addition, as the material of the metal wire, stainless steel, copper, tungsten, nickel, titanium, piano wire, Co-Cr alloy, Ni-Ti alloy, Ni-Ti-Co alloy, Ni-Al alloy, Cu-Zn alloy, Various metal strands such as a superelastic alloy such as a Cu—Zn—X alloy (for example, X = Be, Si, Sn, Al, Ga) or an amorphous alloy can be given.

  Of these materials, stainless steel is preferred for reasons such as workability, economy, and lack of toxicity. The metal wire is preferably a flat wire from the viewpoint of kink resistance or elongation resistance. For example, the thickness is preferably set to about 10 to 40 μm and the width is set to about 80 to 120 μm.

  The inner layer 31N is a layer covered with the reinforcing layer 31M, and has a thickness of about 10 to 50 μm, for example. And as a material of inner layer (inner layer pipe) 31N, for example, polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer Fluorine resin such as coalescence, polyolefin such as polypropylene, polyethylene, ethylene-vinyl acetate copolymer, polyester such as polyamide, polyethylene terephthalate, polybutylene terephthalate, polyurethane, polyvinyl chloride, polystyrene resin, polyimide resin, or , And mixtures thereof.

  In addition, with respect to the stent 29 that passes through the lumen of the outer tube 31 that the inner layer 31N faces, from the viewpoint of having excellent lubricity, it is a polytetrafluoroethylene or a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, The inner layer 31N is preferably formed.

  The inner shaft 49 includes an inner tube (inner tubular member) 41, a pusher marker 43, and a core wire 45.

  The inner tube 41 is a tube having a hollow (lumen), and at least a part thereof is inserted into the lumen 32 of the outer tube 31 of the outer shaft 39. A guide wire (not shown) is inserted into the lumen formed in the inner tube 41 to guide the outer shaft 39 to the lesioned part.

  The inner tube 41 has flexibility enough to follow the inserted lumen, kink resistance, and tensile strength that does not extend when the catheter is pulled during the procedure.

  For example, fluorine resins such as polyimide, polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, ethylene-tetrafluoroethylene copolymer, polypropylene, polyethylene, Polyolefin such as ethylene-vinyl acetate copolymer, polyester such as polyamide, polyethylene terephthalate, polybutylene terephthalate, resin such as polyurethane, polyvinyl chloride, polystyrene resin, polyimide, or a mixture of them is the inner tube 41. It is mentioned as a material. From the viewpoint of lubricity and tensile strength, it is preferable that the inner tube 41 is formed of polyimide.

  The pusher marker 43 is fitted (adhered or welded) around the inner tube 41, fits in the lumen 32 of the outer tube 31, and pushes out the stent 29 from the outer tube 31 as the inner tube 41 moves.

  Therefore, the position of the pusher marker 43 is preferably equal to or longer than the distance of the axial length (full length) of the stent 2 from the tip of the inner tube 41 (the dimension of the pusher marker 43 is appropriately set. Is preferably about 100 to 200 μm and the total length is about 1.0 to 3.0 mm).

  Examples of the material of the pusher marker 43 include one or more materials selected from the group consisting of stainless steel, nickel titanium alloy, tungsten, tantalum, gold, platinum, iridium, and palladium. For example, from the viewpoint of strength, workability, or economic efficiency, stainless steel is preferable as the material of the pusher marker 43.

  Further, when the pusher marker 43 is formed of a radiopaque material, the distal end of the stent delivery catheter 69 is advanced while being visually recognized to the lesioned part in the body lumen under fluoroscopy. In addition, when the stent 29 is disposed, the positional relationship between the stent 29 and the delivery catheter (the stent delivery catheter 69 excluding the stent 29) is also confirmed. Therefore, the stent delivery catheter 69 can transport and release the stent 29 more safely and efficiently.

  The core wire 45 is connected in parallel with the inner tube 41 and is further connected to the pusher marker 43. Specifically, a part of the side surface of the core wire 45 is connected to the inner tube 41, and an end portion of the core wire 45 is connected to one surface of the pusher marker 43 facing the proximal end side (in short, the core wire 45 is It is partially bonded or welded to the inner tube 41 and the pusher marker 43).

  In this case, the operator's force through the operation unit 51 connected to the inner tube 41 and the core wire 45 is not lost to the inner tube 41 and the core wire 45 (that is, the inner shaft 49). It is transmitted. Therefore, the stent delivery catheter 69 carrying the inner shaft 49 can place the stent 29 more safely and efficiently.

  Moreover, as a material of the core wire 45, materials, such as stainless steel or a nickel titanium alloy, are mentioned. In view of strength, workability, or economic reasons, stainless steel is preferable as the material of the core wire 45.

  Moreover, although the dimension of the core wire 45 is set suitably, it is preferable when an outer diameter is set to about 0.20-0.60 mm, for example. Further, the core wire 45 and the inner tube 41 may be integrated by a resin or a metal tube.

  Here, crimping (reducing diameter) of the stent 29 and attachment of the reduced diameter stent 29 to the delivery catheter will be described with reference to FIGS. 1A to 1H.

  FIG. 1A is a cross-sectional view showing a crimping head 71 in a stent crimping apparatus [diameter reducing apparatus]. As shown in FIG. 1B, the crimping head 71 accommodates the stent 29 and has a mechanism for pressing the outside of the stent 29 (in addition, the crimping head 71 accommodates the stent 29 and has a hollow that changes the inner diameter. , Referred to as receiving cavity 72).

  Then, after the stent 29 is disposed in the crimping head 71 of the stent crimping apparatus, the mandrel 19 formed of the solid core rod 11 is inserted into the stent 29 as shown in FIG. 1C. The Thereafter, as shown in FIG. 1D, the stent 29 is pressed outward by the crimping head 71 with the mandrel 19 inside (see white arrow).

  The mandrel 19 shown in FIG. 1C has an outer diameter smaller than the inner diameter of the expanded stent 29 and is made of a solid and relatively hard material. For example, iron, stainless steel, brass, copper, tungsten, nickel, titanium, piano wire, or superelastic alloy {eg, Co-Cr alloy, Ni-Ti alloy, Ni-Ti-Co alloy, Ni-Al alloy, Cu -Zn alloy or Cu-Zn-X alloy (for example, X = Be, Si, Sn, Al, Ga)} is cited as a material for the mandrel 19.

  As shown in FIG. 1D, when the outer side (surface) of the stent 29 is pressed by the crimping head 71, when the mandrel 19 having high hardness supports the inner side of the stent 29, the inner diameter of the stent 29 is The diameter of the stent 29 is reduced to the same level as the outer diameter (the outer diameter of the reduced stent 29 is referred to as the second outer diameter, and the outer diameter of the stent 29 before the diameter reduction is referred to as the first outer diameter). ).

  That is, in order to manufacture the reduced diameter stent 29, the step of placing the stent 29 in the stent crimping device for reducing the diameter of the stent 29 by pressing the stent 29 from the outside, The step of inserting the mandrel 19 (in other words, the core rod 11) and the step of reducing the diameter of the stent 29 from the first outer diameter in the expanded state to the second outer diameter in the reduced state. included.

  After such a process, since the surface of the stent 29 comes into contact with the crimping head 71 and the inner surface of the stent 29 comes into contact with the surface of the mandrel 19, the strut 21 formed by the stent 29 is connected to the crimping head 71. It will be pinched by the mandrel 19. Therefore, the struts 21 flutter up and do not jump to the inside and the outside of the stent 29 (the stent 29 having a uniformly reduced diameter is completed).

  Thereafter, as shown in FIG. 1E (see white arrow), the mandrel 19 is pulled out from the reduced diameter stent 29 (in short, the process of pulling out the mandrel 19 from the stent 29 diameter reduced to the second outer diameter). Exist). In addition, since the strut 21 does not stand up in the reduced diameter stent 29, the mandrel 19 is easily pulled out from the stent 29.

  Next, as shown in FIG. 1F, the accommodation cavity 72 of the crimping head 71 holding the stent 29 in a reduced diameter state and the lumen 32 of the delivery catheter are aligned coaxially (for example, the crimping head). 71 is smaller than the inner diameter of the lumen 32 of the outer tube 31). More specifically, one of both the mouths in the accommodation cavity 72 and the mouth of the lumen 32 (the distal end side mouth) in the outer tube 31 are brought together.

  Thereafter, as shown in FIG. 1G, the hollow bar 12 is inserted into the housing cavity 72 from the other of the both mouths (the mouth that does not contact the outer tube 31) of the housing cavity 72 of the crimping head 71. The outer diameter of the bar 12 is larger than the inner diameter of the reduced diameter stent 29, but smaller than the outer diameter of the reduced diameter stent 29 (in addition, the inner diameter of the bar 12 has a lumen of the outer tube 31). 32 is designed so as not to interfere with the inner tube 41 located in the interior 32).

  Therefore, the bar 12 not only fits in the accommodating cavity 72 of the crimping head 71 but also comes into contact with one peripheral edge at both ends of the stent 29 when approaching the outer tube 31 along the accommodating cavity 72. . Then, as shown in FIG. 1H, when the bar 12 advances toward the outer tube 31, the bar 12 pushes the stent 29 having a reduced diameter and moves it to the delivery catheter. 29 reaches the lumen 32 of the outer tube 31).

  In addition, since the struts 21 are prevented from overlapping in the stent 29 having a uniformly reduced diameter, the operator's force is easily transmitted in the axial direction of the stent 29. Therefore, the stent 29 is easily inserted into the lumen 32 of the delivery catheter without buckling.

  Further, the material of the bar 12 is not particularly limited. For example, iron, stainless steel, brass, copper, tungsten, nickel, titanium, piano wire, or superelastic alloy {for example, Co-Cr alloy, Ni-Ti alloy , Ni—Ti—Co alloy, Ni—Al alloy, Cu—Zn alloy, or Cu—Zn—X alloy (for example, X = Be, Si, Sn, Al, Ga)}.

  Further, the mandrel 19 formed of the core rod 11 as shown in FIG. 1E is not always pulled out. For example, in a state where the core rod 11 is inserted into the stent 29, another hollow rod having an inner diameter larger than the outer diameter of the core rod 11 and larger than the inner diameter of the reduced stent 29 ( In short, the core 29 may be moved to the delivery catheter by pushing the reduced diameter stent 29 with another hollow rod member that allows the core 11 to communicate with the inside.

  However, in such a process, the core rod 11 must be disposed so as not to contact (interfere) with the inner tube 41.

  Incidentally, in FIGS. 1C to 1E, a mandrel 19 formed of a solid core rod 11 is used. However, the present invention is not limited to this. For example, a mandrel 19 formed of a hollow core rod 11 may be used.

  Further, the mandrel 19 may be a type including the core rod 11 and the rod material, and the rod material may be connected to the end of the core rod 11 inserted inside the stent 29.

  The crimping of the stent 29 and the attachment of the reduced diameter stent 29 to the delivery catheter using the mandrel 19 will be described with reference to FIGS. 2A to 2G.

  2A and 2B show a crimping head 71 containing a crimping head 71 and a stent 29, similar to FIGS. 1A and 1B.

  Then, as shown in FIG. 2C, a mandrel 19 in which the end of the hollow bar 12 is connected to the end of the hollow core 11 is inserted inside the stent 29. More specifically, the core 11 is inserted into the accommodating cavity 72 of the crimping head 71 and is inserted into the stent 29, and the bar 12 is not inserted into the accommodating cavity 72 and the stent 29.

  The hollow bar 12 in the mandrel 19 has a larger outer diameter than the core 11 and is connected to the end of the core 11 that is inserted inside the stent 29 ( The core rod 11 and the rod material 12 are connected, and the core rod 11 and the rod material 12 are preferably arranged coaxially). Further, the outer diameter of the bar 12 is larger than the inner diameter of the reduced stent 29, but is smaller than the outer diameter of the reduced stent 29.

  Thereafter, as shown in FIG. 2D (see the white arrow), the stent 29 is pressed outward by the crimping head 71 with the core rod 11 inside.

  That is, in order to manufacture the reduced diameter stent 29, the step of placing the stent 29 in the stent crimping device for reducing the diameter of the stent 29 by pressing the stent 29 from the outside, The step of inserting the core rod 11 of the mandrel 19 and the step of reducing the diameter of the stent 29 from the first outer diameter in the expanded state to the second outer diameter in the reduced state are included.

  Next, similarly to FIG. 1F, the accommodation cavity 72 of the crimping head 71 holding the stent 29 in the reduced diameter state and the lumen 32 of the delivery catheter are aligned coaxially, for example (see FIG. 2E).

  Thereafter, as shown in FIG. 2F, the bar 12 in the mandrel 19 is brought closer to the outer tube 31 along the accommodation cavity 72. Then, the peripheral edge of the bar 12 near the joint with the core bar 11 comes into contact with one peripheral edge at both ends of the stent 29. Then, as shown in FIG. 2G, as the bar 12 advances toward the outer tube 31, the bar 12 pushes the reduced diameter stent 29 and moves it to the delivery catheter.

  Incidentally, the stent delivery catheter 69 shown in FIG. 3 is of a type referred to as a rapid exchange (RX) type. However, the present invention is not limited to this, and there is an over-the-wire (OTW) type stent delivery catheter 69. Unlike the RX type stent delivery catheter 69 (see FIG. 3), the OTW type stent delivery catheter 69 has an inner tube removed as shown in FIG.

  And when the stent 29 is mounted | worn with respect to such an OTW type delivery catheter, the process as shown to FIG. 1A-FIG. 1E may be performed.

  That is, in the crimping of the stent 29, when the mandrel 19 formed of the core rod 11 is used without including the bar 12, the stent crimping device that reduces the diameter of the stent 29 by pressing the stent 29 from the outside is provided. The step of arranging the stent 29, the step of inserting the mandrel 19 (in other words, the core rod 11) inside the stent 29, and the stent 29 from the first outer diameter in the expanded state to the reduced diameter state The step of reducing the diameter to the second outer diameter is performed (note that the core rod 11 in the mandrel 19 may be solid or hollow).

  In the reduced diameter stent 29, as shown in FIG. 6A, the accommodation cavity 72 of the crimping head 71 holding the reduced diameter stent 29 and the lumen 32 of the delivery catheter are aligned coaxially, for example. One of both the mouths in the accommodation cavity 72 and the mouth (the mouth on the distal end side) of the lumen 32 in the outer tube 31 are brought together.

  Thereafter, as shown in FIG. 6B, the solid bar 12 is inserted into the accommodation cavity 72 from the other of the two mouths (the mouth that does not contact the outer tube 31) of the accommodation cavity 72 of the crimping head 71. The outer diameter of the bar 12 is larger than the inner diameter of the reduced stent 29, but smaller than the outer diameter of the reduced stent 29 (that is, unlike the hollow bar 12 shown in FIG. 1G). The bar 12 shown in FIG. 6B may be solid).

  Therefore, the bar 12 not only fits in the accommodating cavity 72 of the crimping head 71 but also comes into contact with one peripheral edge at both ends of the stent 29 when approaching the outer tube 31 along the accommodating cavity 72. . Then, as shown in FIG. 6C, when the bar 12 advances toward the outer tube 31, the bar 12 pushes the reduced diameter stent 29 and moves it to the delivery catheter.

  Further, in the crimping of the stent 29, when the mandrel 19 including the core bar 11 and the bar 12 is used, the steps shown in FIGS. 7A to 7D may be performed.

  That is, the step of placing the stent 29 in the stent crimping device that reduces the diameter of the stent 29 by pressing the stent 29 from the outside (see FIGS. 7A and 7B), and the solid state of the mandrel 19 inside the stent 29 The step of inserting the core rod 11 (see FIG. 7C) and the step of reducing the diameter of the stent 29 from the first outer diameter in the expanded state to the second outer diameter in the reduced state (see FIG. 7D). (That is, unlike the hollow core 11 shown in FIGS. 2C and 2D, the core 11 shown in FIGS. 7C and 7D may be solid).

  Thereafter, as shown in FIG. 7E, the accommodation cavity 72 of the crimping head 71 holding the stent 29 in a reduced diameter state and the lumen 32 of the delivery catheter are aligned coaxially, for example.

  Then, as shown in FIG. 7F, the solid bar 12 in the mandrel 19 is brought close to the outer tube 31 along the accommodation cavity 72. Then, the peripheral edge of the bar 12 near the joint with the core bar 11 comes into contact with one peripheral edge at both ends of the stent 29. Then, as shown in FIG. 7G, as the bar 12 advances toward the outer tube 31, the bar 12 pushes the stent 29 having a reduced diameter and moves it to the delivery catheter (ie, FIG. 2F). -Unlike the hollow bar 12 shown in FIG. 2G, the bar 12 shown in FIGS. 7F and 7G may be solid.

  In the above, the stent 29 has been reduced in outer diameter from the first outer diameter to the second outer diameter, but is not limited thereto.

  For example, the stent 29 includes at least one step of reducing the outer diameter to the third outer diameter until the outer diameter is reduced from the first outer diameter to the second outer diameter. But you can. This is because when the diameter of the stent 29 is gradually reduced, the shape of the struts 21 tends to be uniform, and as a result, the diameter of the stent 29 is uniformly reduced.

  The third outer diameter of the stent 29 is 50% or less of the first outer diameter, and the speed of the diameter reduction is preferably selected from the range of 0.5 m / S to 10.0 m / S. .

  In addition, when the stent 29 reduced in diameter to the second outer diameter is moved to the delivery catheter by the bar 12 while maintaining the reduced diameter state, the stent 29 is cooled with liquid nitrogen or the like. Also good. This is because the stent 29 is difficult to expand from the second outer diameter when cooled.

  Here, while giving the numerical example of an example of the stent delivery catheter 69 mentioned above, the comparative example was also given and they were compared and evaluated. Of course, it is needless to say that the present invention is not limited to this example.

[Example 1]
The stent 29 is a self-expandable type. The stent 29 is formed by laser cutting a nickel titanium alloy pipe having an outer diameter of 3.0 mm, expanded to an outer diameter of 8.0 mm [first outer diameter], and further subjected to heat treatment. .

  Then, a cylindrical mandrel 19 (in other words, core rod 11) having an outer diameter of 1.24 mm is inserted into the stent 29 along the axial direction of the stent 29. Thereafter, the crimping head 71 reduces the outer diameter of the stent 29 to 4.0 mm at a diameter reduction speed of 1.0 m / s to obtain a third outer diameter. Further, the crimping head 71 reduces the outer diameter of the stent 29 from the third outer diameter to 1.72 mm at a diameter reducing speed of 1.0 m / s, and sets the second outer diameter.

  Then, the mandrel 19 is removed from the stent 29 while the stent 29 is kept crimped to the second outer diameter. Thereafter, the end of the crimping head 71 and the end of the stent 29 are butted against the opening of the lumen 32 of the outer tube 31 in the delivery catheter, and the solid rod 12 having an outer diameter of 1.68 mm is used. 29 is pushed out and inserted into the lumen 32 of the outer tube 31.

  The stent delivery catheter 69 is an over-the-wire type (for example, the inner tube 41 formed of polyimide and having a thickness of 20 μm and an inner diameter of 0.53 mm is excluded from the RX-type stent delivery catheter 69). .

  The pusher marker 43 is a cylindrical tube made of SUS304 having a thickness of 180 μm and an inner diameter of 1.25 mm. Note that the pusher marker 43 is adhered to the tip of the core wire 45 with an adhesive and is disposed in the vicinity of 50 mm from the tip of the outer tube 31.

  The core wire 45 is a wire made of SUS304 and having an outer diameter of 0.45 mm. The core wire 45 is covered with a tube (a tube having a thickness of 175 μm and an inner diameter of 1.25 mm) formed of Pebax 5533 having a Shore D hardness of 55.

  The operation unit 51 is made of stainless steel.

  In the outer tube 31, the outer layer (outer layer tube) 31T was formed of a material obtained by blending Pebax 7033 SA01 (ARKEMA) having a Shore D hardness of 70 and Rilsan-AESN (ARKEMA) in a ratio of 3: 1. The outer tube 31 is a tube having a thickness of 125 μm and an inner diameter of 1.75 mm.

  The inner layer (inner tube) 31N is a tube made of polytetrafluoroethylene and having a thickness of 40 μm and an inner diameter of 1.78 mm. On the inner layer 31N, a strand made of SUS304 having a thickness of 25 μm and a width of 100 μm. Is covered with a reinforcing layer 31M braided using 16 strands.

[Comparative Example 1]
Similar to the first embodiment, the stent is a self-expandable type. This stent is formed by laser cutting a nickel titanium alloy pipe having an outer diameter of 3.0 mm, expanded to an outer diameter of 8.0 mm, and further subjected to heat treatment.

  And with respect to this stent, the crimping head reduces the outer diameter of the stent to 4.0 mm at a diameter reduction speed of 1.0 m / s to obtain a third outer diameter. Further, the crimping head reduces the outer diameter of the stent from the third outer diameter to 1.72 mm at a diameter reduction speed of 1.0 m / s, and sets the second outer diameter.

  Then, the end of the crimping head and the end of the stent are abutted with the opening of the lumen of the outer tube in the delivery catheter, and the stent is pushed out by a solid bar material with an outer diameter of 1.68 mm, and the lumen of the outer tube is Inserted.

  The stent delivery catheter is an over-the-wire type similar to that in Example 1.

[Evaluation]
With respect to Example 1 and Comparative Example 1, an evaluation regarding whether or not insertion into a catheter was possible was performed. Specifically, the stent is crimped by a self-expanding stent crimping device SC900 (Machine Solutions Inc). Whether the reduced diameter stent was inserted into a delivery catheter was evaluated. Evaluation was made with the number of samples being 5 in each example (Example 1 and Comparative Example 1).

[Evaluation results]
The evaluation results are as follows. That is, in Comparative Example 1, in all the samples, the crimped stents could not be inserted into the delivery catheter. However, in Example 1, the crimped stent could be inserted into the delivery catheter in all samples.

Insertion success rate to delivery catheter [%]
Example 1 100% (5/5)
Comparative Example 1 0% (0/5)

11 Core rod 12 Bar material 19 Mandrel 21 Strut 22 Roughly corrugated component 29 Stent 31 Outer tube 31N Inner layer 31M Reinforcement layer 31T Outer layer 32 Lumen 39 Outer shaft 41 Inner tube 43 Pusher marker 45 Core wire 49 Inner shaft 69 Stent delivery catheter 71 Clean Ping head

Claims (6)

Placing the stent in a diameter reducing device having a crimping head for reducing the diameter of the stent by pressing the stent from the outside;
A step of inserting the core rod in a mandrel including a core rod and a rod having a larger outer diameter than the core rod, which are connected so as to form a series and arranged coaxially , into the inside of the stent When,
Reducing the diameter of the stent from a first outer diameter to a second outer diameter;
A step of coaxially arranging the accommodation cavity of the crimping head holding the stent in a reduced diameter state and the lumen in the delivery catheter ;
By causing the mandrel to enter the stent in the storage cavity, the peripheral edge of the stent that has been reduced to the second outer diameter is made smaller than the inner diameter of the stent that has been reduced to the second outer diameter. Pushing at the periphery of the bar with the large outer diameter being larger than the outer diameter and moving it to the lumen of the delivery catheter;
A method for producing a stent delivery catheter comprising a delivery catheter having a reduced diameter stent . When the delivery catheter is inserted into the outer tube having the lumen, an inner tube having a pusher marker mounted at a position away from the tip,
The method for producing a stent delivery catheter according to claim 1, wherein the core rod in the mandrel is hollow . The method for manufacturing a stent delivery catheter according to claim 2, wherein the bar in the mandrel is hollow . In the step of reducing the diameter of the stent from the first outer diameter to the second outer diameter, a third outer diameter which is an intermediate outer diameter between the first outer diameter and the second outer diameter. The method for producing a stent delivery catheter according to any one of claims 1 to 3, comprising a step of reducing the diameter of the stent to a diameter at least once . The method for manufacturing a stent delivery catheter according to any one of claims 1 to 4, wherein the stent is cooled while maintaining a reduced diameter state of the stent . The said stent is a self-expandable stent , The manufacturing method of the stent delivery catheter of any one of Claims 1-5 .