JP6026776B2 - Stent delivery catheter manufacturing method and stent attachment device - Google Patents

Description

  The present invention relates to a method for manufacturing a stent delivery catheter and a stent attachment device.

  As a treatment method for expanding a stenosis site or an occlusion site in a living organ such as a blood vessel, a method of placing a stent at the stenosis site or the occlusion site is known. For introducing the stent into the living body, for example, a balloon catheter is used. In this case, a balloon expandable stent is used as the stent.

  A balloon-expandable stent (hereinafter simply referred to as a stent) is formed in a substantially cylindrical shape by a plastically deformable metal material, and can transition between a contracted state and an expanded state by plastic deformation. The stent is attached in a contracted state so as to be in close contact with the outer peripheral surface of the balloon in a contracted state when inserted into a living body, and after being placed at a treatment site, the stent is plastically deformed into an expanded state by expanding the balloon. . Then, the stent is placed in the living body in this expanded state, and the stenosis site or the blocked site is maintained in an expanded state by the placed stent.

  As a method of attaching the stent to the outer peripheral surface of the balloon, an expanded stent is arranged on the outer peripheral side of the balloon in a contracted state, and the arranged stent is compressed from the outer peripheral side by a pressing device on the outer peripheral surface of the balloon. There is known a mounting method for crimping (see, for example, Patent Document 1). In this case, the stent is attached in a contracted state on the outer peripheral surface of the balloon.

Special table 2010-540091

  By the way, in the above-described stent attachment method, after the stent is attached to the balloon, when the compression by the pressing device is released, the stent may be released from the compressed state and expand. In that case, there is a possibility that a sufficient holding force of the stent cannot be secured on the balloon surface.

  The present invention has been made in view of the above circumstances, and it is a main object of the present invention to provide a stent delivery catheter manufacturing method and a stent mounting device that can suitably secure a retention force of a stent on a balloon surface. Is.

  In order to solve the above problems, a method of manufacturing a stent delivery catheter according to a first aspect of the present invention includes a balloon catheter having a balloon that is inflated or deflated using a fluid, and a balloon catheter attached to the outer peripheral surface of the balloon. In a method of manufacturing a stent delivery catheter comprising a stent expanded by expansion, an arrangement step of arranging the stent on the outer peripheral side of the balloon, and a radial direction from the outer peripheral side of the stent arranged by the arrangement step A first pressure-bonding step of reducing the diameter of the stent by applying an inward compression force and pressing the stent onto the outer peripheral surface of the balloon; a release step of releasing the compression force applied to the stent; and the release After the step, fluid is supplied to the balloon to pressurize the balloon, and the pressurized balloon is By pressing from the inner circumferential side of the cement, characterized in that it comprises a second bonding step of crimping the stent on the outer circumferential surface of said balloon.

  According to the present invention, first, a compressive force from the outer peripheral side to the radially inner side is applied to the stent disposed on the outer peripheral side of the balloon, the diameter of the stent is reduced by the applied compressive force, and the outer peripheral surface of the balloon. Crimped to After the stent is crimped, the compression force applied to the stent is released. In this case, it is conceivable that the stent is released from the compressed state and expands outward in the radial direction, and there is a concern that a sufficient holding force of the stent cannot be secured on the balloon. Therefore, in view of this point, in the present invention, after releasing the compression force applied to the stent, fluid is supplied to the balloon to pressurize the balloon, and the pressurized balloon is pressed against the stent so that the stent is applied to the balloon. I try to crimp it. In other words, according to the present invention, even if the stent expands with the release of the compressive force applied to the stent, the stent can be re-bonded onto the balloon by subsequently pressurizing the balloon and pressing it against the stent. Thereby, the retention strength of the stent on the balloon surface can be suitably secured.

  By the way, after the stent is expanded by releasing the compression force applied to the stent, the stent is re-bonded onto the balloon by applying a compression force to the stent again from the outer peripheral side (in other words, corresponding to the first pressure-bonding step). It is also conceivable to repeat the process). However, in such a case, the stent may be re-expanded (recoiled) after releasing the compression force applied to the stent after the re-bonding, and in that case, there is a possibility that a sufficient holding force of the stent cannot be secured on the balloon. In this regard, in the above configuration in which the balloon is pressurized and the balloon is pressed against the stent from the inner peripheral side to re-compress the stent on the balloon, in other words, the above-described re-compression on the balloon without compressing the stent. In this configuration, the stent can be re-bonded onto the balloon without causing re-expansion of the stent. Therefore, also from this point, it can be said that the above-described configuration is a preferable configuration for suitably securing the retention force of the stent on the balloon.

  In the method for manufacturing a stent delivery catheter according to a second aspect of the present invention, in the first aspect, in the second pressure-bonding step, the balloon is pressurized while restricting expansion of the stent toward the radially outer side. Features.

  According to the present invention, since the balloon is pressed against the stent from the inner peripheral side in a state in which expansion of the stent to the radially outer side is restricted, the pressing force of the balloon against the stent can be suitably exerted. Can do. Thereby, a stent can be suitably crimped | bonded on a balloon outer peripheral surface, and the retention strength of the stent on a balloon can be aimed at.

  In the method for manufacturing a stent delivery catheter according to the third invention, in the second invention, in the second pressure-bonding step, the outer diameter of the stent is increased with release of the compressive force applied to the stent in the releasing step. The expansion of the stent is regulated so as not to be larger than the outer diameter of the stent after expansion.

  When the stent is mounted on the balloon in a stable state (for example, in which the stent is not recoiled), the outer diameter of the stent after the stent is recoiled (expanded) with the release of the compressive force applied to the stent (hereinafter, after expansion) In accordance with the outer diameter), it is desirable to press the balloon against the stent, that is, re-press the stent onto the balloon. In this regard, in the present invention, the balloon is pressed against the stent while restricting the expansion of the stent so that the outer diameter of the stent does not become larger than the outer diameter after expansion. It can be re-bonded (that is, attached) in the state. As a result, the holding force of the stent on the balloon can be ensured more suitably.

  A method for manufacturing a stent delivery catheter according to a fourth aspect of the present invention is the method for manufacturing a stent delivery catheter according to any one of the first to third aspects, wherein a series of steps including the first crimping step and the releasing step are performed a plurality of times, A crimping process is performed.

  When compressing a stent by applying a compressive force from the outer peripheral side to the stent and crimping the stent onto the balloon, the application of the compressive force is canceled as the amount of the diameter to be reduced (the amount of diameter reduction) increases. It is thought that the amount (degree) of recoil of the later stent increases. In this respect, in the present invention, since the compression force is applied to the stent, that is, the stent is contracted a plurality of times, the compression force is not applied as compared with the case where the stent is contracted only once. The recoil amount of the stent can be reduced. Therefore, the stent can be pressure-bonded to the balloon in a state where the outer diameter of the stent is made as small as possible in the second pressure-bonding step after releasing the compression force.

  A stent attachment device according to a fifth aspect of the invention is used when attaching a stent that is expanded by inflation of a balloon on an outer peripheral surface of a balloon that is inflated or deflated using a fluid in a balloon catheter. A pressurizing device that pressurizes the balloon by supplying, and a placement region in which the balloon and the stent are placed in a state where the stent is located on the outer peripheral side of the balloon, and the stent placed in the placement region A pressing device that applies a compressive force directed radially inward from the outer peripheral side thereof by a pressing member, and applying the compressive force to the stent by the pressing device, A first crimping means for reducing the diameter of the stent and crimping the balloon onto the outer peripheral surface of the balloon; Release means for releasing the compression force applied, and releasing the application of the compression force by the release means, and then pressurizing the balloon by the pressurizing device, so that the pressurized balloon is contained in the stent. And a second crimping means for crimping the stent onto the outer circumferential surface of the balloon by pressing from the circumferential side.

  According to the stent attachment device of the present invention, first, a compressive force inward in the radial direction is applied to the stent disposed on the outer peripheral side of the balloon by the pressing member of the pressing device, whereby the stent is placed on the outer peripheral surface of the balloon. Crimped. Thereafter, the application of the compressive force by the pressing device is released. In this case, it is conceivable that the stent is released from the compressed state and expanded. Thereafter, the balloon is pressurized by a pressurizing device, and the pressurized balloon is pressed against the stent from the inner peripheral side, whereby the stent is re-press-bonded onto the outer peripheral surface of the balloon. Thereby, similarly to the first invention, the retention force of the stent can be suitably ensured on the balloon.

  The stent attachment device according to a sixth aspect of the present invention is the stent attachment device according to the fifth aspect, wherein the pressing member is arranged on the outer peripheral side of the stent by the pressing device when the second pressing means is pressed. It is provided with the control means which controls expanding toward.

  According to the present invention, when the stent is (re-) crimped onto the balloon by pressing the balloon against the stent, the pressing member of the pressing device is arranged on the outer peripheral side of the stent so as to extend radially outward of the stent. Since expansion is regulated, the pressing force of the balloon against the stent can be suitably exerted. Thereby, since the stent can be suitably pressure-bonded on the outer peripheral surface of the balloon as in the case of the second invention, the retention of the stent on the balloon can be improved.

1 is a schematic overall side view showing the configuration of a stent delivery catheter. (A) is a side view showing the configuration of the balloon and its surroundings in the inflated state, (b) is a side view showing the configuration of the balloon and its surroundings in the deflated state, and (c) is a cross-sectional view taken along line AA in (b) It is. The figure which shows schematic structure of a stent attachment apparatus. The front view which shows the structure of a press apparatus. Explanatory drawing for demonstrating the attachment process at the time of attaching a stent to a balloon. The flowchart which shows a stent attachment process.

  Hereinafter, an embodiment of a balloon-expandable stent delivery catheter 10 which is a kind of catheter will be described with reference to the drawings. First, a schematic configuration of the stent delivery catheter 10 will be described with reference to FIG. FIG. 1 is a schematic overall side view showing a configuration of a stent delivery catheter 10. For the sake of illustration, the periphery of the balloon 13 is shown larger than the actual size.

  As shown in FIG. 1, the stent delivery catheter 10 includes a balloon catheter 20 and a stent 14 attached on the balloon 13 of the balloon catheter 20. The balloon catheter 20 includes a catheter tube 11, a hub 12 attached to the proximal end portion (base end portion) of the catheter tube 11, and a balloon 13 attached to the distal end side (tip end side) of the catheter tube 11. And. The length dimension of the stent delivery catheter 10 is 1 m to 2 m.

  In the balloon catheter 20, the catheter tube 11 is composed of a plurality of tubes, and has an inner and outer multi-tube structure from the middle position in the axial direction (longitudinal direction) to the position of the balloon 13. Specifically, the catheter tube 11 includes an outer tube 15 and an inner tube 16 having a diameter smaller than that of the outer tube 15, and the inner tube 16 is inserted into the outer tube 15. It has an inner and outer double pipe structure.

  The outer tube 15 is formed in a tubular shape having outer tube holes 21 (see FIG. 2) that are continuous over the entire axial direction and open at both ends. The outer tube 15 is connected to the hub 12 at the proximal end and is formed with a metal such as a Ni—Ti alloy or stainless steel, and on the distal side with respect to the outer proximal tube 22. An outer intermediate tube 23 formed of a thermoplastic polyamide elastomer so as to be lower in rigidity than the outer proximal tube 22 continuously, and continuous with the outer intermediate tube 23 on the distal side, than the outer intermediate tube 23 And an outer distal tube 24 formed of a thermoplastic polyamide elastomer so as to have low rigidity.

  The inner tube 16 is formed in a tubular shape having inner tube holes 31 (see FIG. 2) that are continuous over the entire axial direction and open at both ends. The proximal end of the inner tube 16 is joined to an intermediate position in the axial direction of the outer tube 15, specifically, the boundary between the outer intermediate tube 23 and the outer distal tube 24. Moreover, the inner tube 16 is provided in a state in which a part thereof is extended distally than the outer tube 15, and the balloon 13 is provided so as to cover the extended region from the outside. .

  The outer tube hole 21 of the outer tube 15 functions as a fluid lumen through which a compressed fluid flows when the balloon 13 is inflated or deflated, and the inner tube hole 31 of the inner tube 16 is a guide wire through which the guide wire G is inserted. Serves as a lumen. Further, the proximal end opening 31a of the inner tube hole 31 is located at a midway position in the axial direction of the stent delivery catheter 10, and therefore the present catheter 10 is configured as a so-called RX type catheter. However, the present invention is not limited to this, and a so-called over-the-wire type catheter in which the proximal end opening 31 a of the inner tube hole 31 exists at the proximal end portion of the catheter 10 may be used.

  Next, the configuration of the balloon 13 and its surroundings will be described with reference to FIG. 2A is a side view showing the configuration of the balloon 13 in the inflated state and its surroundings, FIG. 2B is a side view showing the configuration of the balloon 13 in the deflated state and its surroundings, and FIG. It is AA sectional view.

  As described above, the balloon 13 is provided so as to cover a region of the inner tube 16 that extends more distally than the outer tube 15 (hereinafter, this region is referred to as an extended region 26) from the outside. The balloon 13 is joined at its proximal end to the distal end of the outer tube 15 (specifically the outer distal tube 24) and at its distal end is the inner tube 16 (specifically its extension region 26). It is joined to the distal end side.

  The balloon 13 is made of thermoplastic polyamide. However, it is not limited to this, and other synthetic resins such as polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide elastomer, polyimide, polyimide elastomer, polyurethane, polyurethane elastomer, polyethylene terephthalate, silicon rubber, styrene olefin rubber, etc. It may be formed. Moreover, you may form with the material which mixed 2 or more types among the synthetic resin enumerated in this way, and the said polyamide elastomer, In this case, it may be a single layer structure and may be a multilayer structure.

  The production method of the balloon 13 is not particularly limited, and examples thereof include a production method by blow molding, dipping molding, extrusion molding, and the like. However, in the case of dilatation treatment of a stenosis occurring in the coronary artery of the heart, it is preferable that the balloon 13 has a sufficient pressure resistance, and in this case, blow molding is preferable.

  The balloon 13 has joint portions at both ends joined to the catheter tube 11, and an expansion / contraction portion that is provided between the joint portions and expands and contracts. Specifically, the balloon 13 has a proximal leg region 13a joined to a distal end portion of the outer tube 15 (outer distal tube 24), and an inner diameter and an outer diameter continuously toward the distal side. A proximal cone region 13b that is tapered so as to be expanded, a straight tube region 13c that has the same inner diameter and outer diameter in the entire length direction and that forms the maximum outer diameter region of the balloon 13, A distal cone region 13d that is tapered so that the inner diameter and the outer diameter are continuously reduced toward the distal side, and a distal leg region 13e that is joined to the extension region 26 of the inner tube 16; In this order from the proximal side. The joining of the outer tube 15 and the proximal leg region 13a and the joining of the inner tube 16 and the distal leg region 13e are both performed by thermal welding. However, these joining does not necessarily need to be performed by heat welding, and other joining methods such as adhesion using an adhesive may be employed.

  The balloon 13 is inflated when a fluid is pressurized and supplied into the balloon 13 through the outer tube hole 21 of the outer tube 15 (see FIG. 2A), and a negative pressure is applied to the outer tube hole 21. When the fluid is discharged from the balloon 13, the fluid is contracted (see FIG. 2B).

  As shown in FIG. 2C, the balloon 13 includes a plurality (three in FIG. 2C) of wings 27 formed in the contracted state. These wings 27 are provided in the circumferential direction of the balloon 13 at a predetermined interval (specifically, at equal intervals). Each wing 27 is formed so as to extend in the axial direction in the expansion / contraction portion (proximal cone region 13b, straight tube region 13c and distal cone region 13d) of the balloon 13, and more specifically in the expansion / contraction portion. It is formed continuously from the proximal end (proximal end of the proximal cone region 13b) to the vicinity of the distal end (distal end of the distal cone region 13d). When the balloon 13 is in a deflated state, each of the wings 27 is folded to one side in the circumferential direction of the balloon 13 and is wound around the inner tube 16. In FIG. 2C, each wing 27 is wound around the inner tube 16 in a counterclockwise direction. And the stent 14 is attached on the outer peripheral surface of the balloon 13 of this wound state.

  Note that the number of wings 27 formed on the balloon 13 in the contracted state is not limited to three, but may be two, four, five, or six.

  A stent 14 is attached on the outer peripheral surface of the balloon 13. The stent 14 is formed in a substantially cylindrical shape from a plastically deformable metal material, and transitions between a contracted state and an expanded state in which the outer diameter is larger than that by performing plastic deformation. . Specifically, the stent 14 is made of a cobalt chromium alloy. However, the stent 14 does not necessarily need to be formed of a cobalt chromium alloy, and may be formed using another metal material such as stainless steel or a biodegradable resin such as polylactic acid. Further, as the stent 14, a metal stent surface or a resin stent surface provided with a drug may be used.

  The stent 14 is attached in a contracted state on the outer peripheral surface of the straight tube region 13 c of the balloon 13. The stent 14 has a length in the axial direction equal to or shorter than the length in the axial direction of the straight tube region 13c, so that both ends thereof do not protrude from the straight tube region 13c. It is attached. The stent 14 transitions to an expanded state while undergoing plastic deformation by receiving an external force directed radially outward by the balloon 13 when the balloon 13 is inflated.

  A pair of contrast rings 32 and 33 are attached to the inner tube 16. Each of the contrast rings 32 and 33 is disposed at both side positions of the inner tube 16 with the stent 14 sandwiched in the axial direction. Each of the contrast rings 32 and 33 is formed of a metal having an X-ray contrast function, specifically, stainless steel, and the position thereof can be specified by projecting X-rays.

  Next, an attachment procedure when attaching the stent 14 on the outer peripheral surface of the balloon 13 in the balloon catheter 20 will be described. The stent 14 is attached to the balloon 13 using a stent attachment device 40. First, prior to the description of the procedure for attaching the stent 14 to the balloon 13, the stent attachment device 40 will be described with reference to FIG. FIG. 3 is a diagram showing a schematic configuration of the stent attachment device 40.

  As shown in FIG. 3, the stent attachment device 40 includes a pressing device 41 and a pressing device 42 as main devices, and a controller 43 for controlling the operations of the devices 41 and 42. The pressing device 41 is a device that applies a pressing force (compression force) from the outer peripheral side to the stent 14 so as to press the stent 14 onto the outer peripheral surface of the balloon 13. FIG. 4 is a front view showing the configuration of the pressing device 41.

  As shown in FIG. 4, the pressing device 41 includes a base plate 45 having a circular opening 47 and a plurality of pressing members 46 (ten in FIG. 4) provided at predetermined intervals around the central axis of the opening 47. With. The pressing member 46 has a plate shape having a plate surface parallel to the plate surface of the base plate 45, and the thickness thereof is greater than the total length (length in the axial direction) of the stent 14 (in other words, the straight tube region 13c of the balloon 13). Is also big. The pressing member 46 is formed so as to extend from the opening edge portion of the opening 47 in the base plate 45 toward the central axis side of the opening 47. Specifically, the pressing member 46 is tapered so as to be tapered toward the central axis side of the opening 47. It has a triangular shape.

  An inner region surrounded by each pressing member 46 is an arrangement region 50 in which the balloon 13 and the stent 14 attached to the balloon 13 are arranged. The balloon 13 and the stent 14 are arranged in the same region 50 with their respective axial directions directed toward the central axis A1 of the arrangement region 50. The pressing members 46 are arranged radially around the arrangement area 50 and are arranged at equal intervals around the central axis A1 of the area 50. Each pressing member 46 is formed with a pressing surface portion 46a that presses the stent 14 arranged in the arrangement region 50 from the outer peripheral side.

  Each pressing member 46 is pivotally supported by a base plate 45 so as to be rotatable via a rotation shaft portion 48 disposed around the opening 47. The central axis A2 of the rotation shaft portion 48 is an axis extending in the same direction as the central axis A1 of the arrangement region 50 (in other words, the axial direction of the balloon 13 and the stent 14 arranged in the region 50). The rotation shafts 48 of the respective pressing members 46 are arranged such that their center axes A2 are located on the same circle (indicated by a two-dot chain line in FIG. 4). Is located at the same position as the central axis A1.

  Each pressing member 46 is configured to rotate in the same direction about the central axis A2 of the rotating shaft portion 48, and the size of the arrangement region 50 is changed by the rotation of the pressing member 46. It has become. More specifically, assuming a virtual inscribed circle X (indicated by a one-dot chain line in FIG. 4) inscribed in the pressing surface portion 46a of each pressing member 46, each pressing member 46 is on one side in the rotation direction (clockwise in FIG. 4). When rotating in the (rotating direction), the diameter of the virtual inscribed circle X decreases, and when rotating in the other side (counterclockwise direction in FIG. 4), the diameter of the virtual inscribed circle X increases.

  Each pressing member 46 is rotated about the central axis A2 of the rotation shaft portion 48, and the initial position shown in FIG. 4B (in other words, the compression release position) and the compression position shown in FIG. It is possible to move to and from the pressing position. When each pressing member 46 is in the initial position, the diameter of the virtual inscribed circle X is larger than the outer diameter of the stent 14 in the expanded state, and when each pressing member 46 is in the compressed position, the virtual inscribed circle X The diameter of the circle X is the same as or substantially the same as the outer diameter of the stent 14 in the contracted state. In the following description, the diameter of the virtual inscribed circle X when each pressing member 46 is in the compression position is referred to as a stent compression diameter DL. The stent compression diameter DL is variable within a predetermined range.

  Here, in the pressing device 41, when the stent 14 is arranged in the arrangement region 50 and each pressing member 46 is moved from the initial position to the compressed position in the arrangement state, the outer surface of the stent 14 is caused to have a diameter by each pressing member 46. A compressive force (pressing force) inward in the direction is applied. As a result, the stent 14 is compressed radially inward and crimped onto the balloon 13 (FIG. 4C). At this time, since each pressing member 46 moves from the initial position to the compression position while rotating, a rotational force in the circumferential direction is applied to the outer surface of the stent 14 by the pressing members 46 in addition to the compression force. Is done. For this reason, the stent 14 is crimped onto the balloon 13 while rotating in the circumferential direction with respect to the balloon 13. In the following, the rotation direction in which the stent 14 rotates with respect to the balloon 13 is referred to as the stent rotation direction.

  Each pressing member 46 is rotationally driven by a driving device 52. The drive device 52 is configured by, for example, an electric motor. When the driving device 52 is driven, the pressing members 46 rotate in synchronization with the same side. That is, each pressing member 46 is moved between the initial position and the compression position by driving the driving device 52.

  The pressurizing device 42 pressurizes the balloon 13 by supplying fluid to the balloon 13 and decompresses the balloon 13 by sucking (discharging) the fluid from the balloon 13. The pressurizing device 42 is constituted by, for example, a known fluid pump. The pressurizing device 42 is connected to the hub 12 of the balloon catheter 20, and supplies fluid to the balloon 13 through the hub 12 and the outer tube 15 in the connected state, or sucks and removes fluid from the balloon 13.

  The controller 43 is constituted by a known microcomputer having a CPU and the like. The controller 43 is connected to the operation device 53 and is connected to the drive device 52 and the pressure device 42 of the pressing device 41. The controller 43 controls the operation of the driving device 52 and the pressurizing device 42 based on an operation on the operating device 53 or the like.

  Then, the attachment process at the time of attaching the stent 14 on the balloon 13 using the said stent attachment apparatus 40 is demonstrated. FIG. 5 is an explanatory diagram for explaining an attachment process when attaching the stent 14 to the balloon 13.

  First, as shown in FIG. 5 (a), an arrangement step of arranging the expanded stent 14 on the outer peripheral side of the balloon 13 of the balloon catheter 20 is performed. In this step, the balloon 13 and the stent 14 are arranged in the arrangement region 50 of the pressing device 41 in a state where the stent 14 is positioned on the outer peripheral side of the balloon 13 (straight tube region 13c) (see also FIG. 4B). At this time, the balloon 13 is arranged in the arrangement region 50 so that the winding direction of each wing 27 is the same as the stent rotation direction of the stent 14.

  Next, as shown in FIG. 5 (b), the stent 14 is contracted by applying a compressive force directed radially inward from the outer peripheral side to the stent 14 disposed on the outer peripheral side of the balloon 13. In other words (in other words, in a contracted state), a first pressure-bonding process is performed in which the balloon 13 (specifically, the straight tube region 13c) is pressure bonded. In this step, each pressing member 46 of the pressing device 41 is moved to the compression position, thereby applying a compressive force to the outer surface of the stent 14 by each pressing member 46 (pressing surface portion 46a) (see also FIG. 4C). ). At this time, each pressing member 46 is moved to a position (compression position) where the stent compression diameter DL becomes DL1. Thereby, the outer diameter DS1 of the stent 14 becomes the same size as the stent compression diameter DL1 (DL1 = DS1). DL1 is smaller than the final outer diameter of the stent 14, that is, the target outer diameter DX of the stent 14 (DL1 <DX).

  More specifically, regarding the crimping of the stent 14 by each pressing member 46, in addition to the pressing, the outer surface of the stent 14 is given a compressive force inward in the radial direction by each pressing member 46. More specifically, a rotational force in the same direction as the winding direction of the wing 27 is applied in the circumferential direction (stent rotation direction). Therefore, the stent 14 is compressed (compressed) along the outer periphery of the balloon 13 while rotating in the same direction as the winding direction of the wings 27. More specifically, after the inner surface of the stent 14 comes into contact with the outer peripheral surface of the balloon 13 during the crimping, the inner surface of the stent 14 is rotated 1/100 to 1/30 with respect to the outer peripheral surface of the balloon 13. The

  Note that the compression force applied to the stent 14 by each pressing member 46 is continuously performed for a predetermined time. Here, the predetermined time is a time sufficient to plastically deform the stent 14 in a contracted state, and is, for example, 30 to 60 seconds.

  Further, in the first pressure-bonding step, a compressive force is applied to the stent 14 by each pressing member 46 in a state where a fluid is supplied to the balloon 13 by the pressurizing device 42 and the balloon 13 is pressurized. In this case, the compression force is applied to the stent 14 in a state where the outer peripheral surface of the balloon 13 is pressed against the stent 14 by pressurizing the balloon 13. Therefore, the stent 14 can be suitably crimped to the balloon 13.

  The balloon 13 may be heated instead of or in addition to pressurizing the balloon 13. In this case, since the stent 14 can be pressure-bonded to the balloon 13 while the balloon 13 is softened by heat, the stent 14 can be easily bite into the surface of the balloon 13 and the stent 14 can be held on the balloon 13. Easy to improve power. In heating the balloon 13, for example, a heating device such as a heater for heating the pressing member 46 may be provided, and the balloon 13 may be heated by the heating device via the pressing member 46.

  In the first crimping step, a compressive force applied to the stent 14 by each pressing member 46 while inserting a mandrel into the inner tube hole 31 of the extension region 26 of the inner tube 16 to restrict deformation to the inner side of the tube 16. It is desirable to give The mandrel (corresponding to a core material) is made of a metal bar having an outer diameter that is the same as the inner diameter of the inner tube 16. In this case, a compression force radially inward can be applied to the stent 14 while restricting the balloon 13 wound around the inner tube 16 from being deformed radially inward. Therefore, the stent 14 can be suitably crimped onto the balloon 13.

  Next, a releasing step for releasing the application of compressive force to the stent 14 is performed. In this step, as shown in FIG. 5C, by applying the pressing members 46 of the pressing device 41 to the initial position, the compression force applied to the stent 14 by the pressing members 46 is released. As a result, the stent 14 is released from the compressed state and expands (recoils), and the outer diameter of the stent 14 is larger than that of DS1. Note that the release of the compression force applied to the stent 14 is performed for a predetermined time. Here, the predetermined time (hereinafter also referred to as a release time) is the same as or longer than the time required for the stent 14 released from the compressed state to expand (recoil) (more specifically, fully expand). The time is set, for example, 3 to 10 seconds. Further, recoil means an elastic deformation immediately after the stent 14 is released from the compressed state.

  In this release step, the inside of the balloon 13 is decompressed by sucking (discharging) the fluid from the balloon 13 by the pressurizing device 42. However, the balloon 13 may be kept pressurized without depressurizing the balloon 13.

  After the releasing step, the first pressure bonding step and the releasing step are performed again in this order. That is, in the present stent attachment process, a series of processes including the first crimping process and the releasing process are repeated twice. In the second first press-bonding step, the stent 14 is compressed again by the pressing member 46. As a result, the outer diameter of the stent 14 becomes DS1 again. Thereafter, a second releasing step is performed. By this releasing step, the stent 14 is released from the compressed state and expanded again, and the outer diameter thereof becomes DS2 (see FIG. 5C) larger than DS1 (DS1 <DS2). DS2 has the same size as the target outer diameter DX of the stent 14 (DS2 = DX).

Next, as shown in FIG. 5D, the balloon 13 is pressurized by supplying a fluid to the balloon 13 by the pressurizing device 42, and the pressurized balloon 13 (specifically, the straight tube region 13c) is stented. A second pressure-bonding step is performed in which the stent 14 is pressure-bonded onto the outer peripheral surface of the balloon 13 by being pressed from the inner peripheral side against 14. As described above, since the stent 14 that has been crimped to the balloon 13 in the first crimping process is expanded in the releasing process, there is a possibility that a sufficient holding force of the stent 14 on the balloon 13 cannot be secured. In this regard, in the present stent attachment process, the balloon 14 is pressed against the expanded stent 14 and pressed against the expanded stent 14 in this second crimping process, so that the stent 14 is re-bonded onto the balloon 13. Therefore, it is possible to suitably secure the holding force of the stent 14 on the balloon 13. The pressurization of the balloon 13 is performed within a pressure range of, for example, 50 to 200 × 10 ⁴ Pa.

  In the second crimping step, the balloon 13 may be heated as described in the first crimping step. Then, since the balloon 13 can be pressed against the stent 14 in a softened state, the stent 14 can be easily bited into the balloon 13, and the retention force of the stent 14 on the balloon 13 can be easily improved. be able to.

  In the second pressure-bonding step, the balloon 13 is pressurized while restricting the stent 14 from expanding radially outward. In this case, each pressing member 46 of the pressing device 41 is arranged on the outer peripheral side of the stent 14 by moving to the compression position, and the expansion of the stent 14 is regulated by each arranged pressing member 46. Specifically, at this time, each pressing member 46 is moved to a position where the stent compression diameter DL becomes DL2 (compression position) (DL1 <DL2). This DL2 has the same size as the outer diameter DS2 of the stent 14 expanded in the above-described releasing step (DL2 = DS2). That is, each pressing member 46 is arranged according to the size (outer diameter DS2) of the stent 14 expanded in the releasing step. From the point that each pressing member 46 is used to restrict the expansion of the stent 14 as described above, the compression position at this time (that is, the compression position where the stent compression diameter becomes DL2) can also be referred to as an expansion restriction position. .

  As described above, the pressing force of the balloon 13 against the stent 14 can be suitably exerted by pressing the balloon 13 and pressing the stent 14 while restricting the expansion of the stent 14. Therefore, the stent 14 can be suitably crimped | bonded to the balloon 13, As a result, the retention strength of the stent 14 on the balloon 13 can be aimed at.

  After performing a 2nd crimping | compression-bonding process, each press member 46 is moved to an initial position, and the balloon 13 with which the stent 14 was attached is removed from the arrangement | positioning area | region 50 of the press apparatus 41. FIG. Thereby, a series of stent attachment processes are completed.

  As described above, in the present stent attachment process, the balloon 13 is pressurized by pressing the balloon 13 in the crimping process (specifically, two first crimping processes and one second crimping process) that are performed a plurality of times. The second crimping step for crimping the stent 14 onto the balloon 13 by pressing against the stent 14 from the inner peripheral side is the crimping step performed last. That is, since the last crimping process is a process of crimping the stent 14 onto the balloon 13 without applying a compressive force to the stent 14 from the outer peripheral side, after the stent mounting process is finished (that is, the balloon 13 The stent 14 will not recoil after the stent 14 is mounted thereon. Therefore, also from this point, it is possible to suitably secure the holding force of the stent 14 on the balloon 13.

  By the way, the above-described stent attachment process (specifically, the first crimping process, the releasing process, and the second crimping process) may be performed by a control process (stent attachment process) by the controller 43 of the stent attachment device 40. Therefore, the content of the stent attachment process executed by the controller 43 will be described below with reference to FIG. FIG. 6 is a flowchart showing a stent attachment process. This process is started with a start operation on the controller device 53 as a trigger. This starting operation is performed after the stent 14 and the balloon 13 are arranged in the arrangement region 50 of the pressing device 41, that is, after the above-described arrangement process is performed.

  The controller 43 is provided with a storage unit 54 (see FIG. 3). In addition to the control program for executing the stent attachment process, the storage unit 54 has various data necessary for the stent attachment process. (For example, stent compression diameters DL1, DL2, etc.) are stored in advance.

  As shown in FIG. 6, first, in step S <b> 11, the stent compression diameter DL <b> 1 that defines the compression position of each pressing member 46 during the first crimping process is read from the storage unit 54. In the subsequent step S12, each pressing member 46 is moved to the compression position by driving the driving device 52, specifically, to the position (compression position) where the stent compression diameter DL becomes the read DL1. Thereby, a compressive force inward in the radial direction is applied to the stent 14 by each pressing member 46, and the stent 14 is crimped to the balloon 13 by the compressive force.

  In the next step S13, the pressurizing device 42 is driven to supply a compressed fluid to the balloon 13 to pressurize the balloon 13. That is, in the attachment process, the first crimping process described above is performed in steps S12 and S13. Note that step S13 and step S12 may be reversed.

  In step S14, each pressing member 46 is moved to an initial position by driving the driving device 52. Thereby, the application of the compressive force by the pressing members 46 to the stent 14 is released. In the next step S15, the fluid is discharged from the balloon 13 by driving the pressurizing device 42, and the balloon 13 is depressurized. In this case, the release process described above is performed in steps S14 and S15.

  In step S16, it is determined whether or not the processes in steps S11 to S15 have been performed twice. When the processes of steps S11 to S15 are performed only once, the process returns to step S11 and the processes of steps S11 to S15 are performed again. On the other hand, when the above steps S11 to S15 are performed twice, the process proceeds to step S17. That is, in this attachment process, a series of processes including the first crimping process and the releasing process described above are performed twice by the processes of steps S11 to S16.

  In step S <b> 17, the stent compression diameter DL <b> 2 that defines the compression position of each pressing member 46 during the second crimping process is read from the storage unit 54. In the subsequent step S18, each pressing member 46 is moved to the compressed position by driving the driving device 52, specifically, to the position where the stent compression diameter DL becomes the read DL2 (compressed position). . Thereby, each pressing member 46 is arrange | positioned at the outer peripheral side of the stent 14, and the expansion to the radial direction outer side of the stent 14 is controlled.

  In step S19, the pressurizing device 42 is driven to supply the compressed fluid to the balloon 13 and pressurize the balloon 13. Thereby, the pressurized balloon 13 is pressed against the stent 14, and the stent 14 is pressed against the balloon 13 by the pressing. That is, in this attachment process, the second crimping process described above is performed in steps S18 and S19. Step S18 and step S19 may be reversed.

  In step S20, the pressurizing device 42 is driven to discharge the fluid from the balloon 13 to depressurize the balloon 13. In step S21, the driving device 52 is driven to move each pressing member 46 to the initial position. Thereafter, this process is terminated.

  Next, description will be made on the work contents when the stent 14 is placed at a stenosis site in the body using the stent delivery catheter 10.

  First, a guiding catheter is inserted into a sheath introducer inserted into a blood vessel, and is introduced to the coronary artery entrance by pushing and pulling. Next, the guide wire G is inserted into the inner lumen 31 of the stent delivery catheter 10 and introduced from the coronary artery entrance to the peripheral site through the stenosis. Subsequently, the stent delivery catheter 10 is inserted into the body along the guide wire G while pushing and pulling, and the stent 14 on the balloon 13 is transported to the stenosis site. As described above, in this embodiment, since the holding force of the stent 14 on the balloon 13 is sufficiently secured, the stent 14 is displaced or dropped from the balloon 13 when the stent 14 is transported. Inconvenience is suppressed.

  After the stent 14 is transported to the stenosis, a compressed fluid is injected into the balloon 13 from the hub 12 side using a pressurizer, and the balloon 13 is inflated. Thereby, the stent 14 in a contracted state is plastically deformed to be in an expanded state, and the narrowed portion is expanded by the expanded stent 14. Thereafter, the compressed fluid injected into the balloon 13 is extracted, the balloon 13 is deflated, and the balloon catheter 20 is extracted from the body. Thereby, the placement operation of the stent 14 is completed, and the expanded state of the blood vessel is maintained by the placed stent 14.

  As mentioned above, according to the structure of this embodiment explained in full detail, the following outstanding effects are acquired.

  When the stent 14 is mounted on the balloon 13 in a stable state, the balloon 13 is pressed against the stent 14 in accordance with the outer diameter DS2 of the stent 14 after the stent 14 is recoiled with the release of the compressive force applied to the stent 14, that is, the balloon It is desirable to re-compress stent 14 onto 13. In this regard, in the above embodiment, in the second pressure-bonding step, the expansion of the stent 14 is restricted so that the outer diameter of the stent 14 does not become larger than the stent outer diameter DS2 after expansion (after recoil), and the balloon 13 is subjected to an additional process. Since the pressure is applied, the stent 14 can be re-bonded (that is, attached) on the balloon 13 in a stable state. As a result, the holding force of the stent 14 on the balloon 13 can be more suitably ensured.

  Further, when the stent 14 is pressed onto the outer peripheral surface of the balloon 13 by pressurizing the balloon 13 and pressing it against the stent 14, the stent 14 may expand due to the pressing force of the balloon 13. In that case, as soon as the pressing of the balloon 13 against the stent 14 is stopped, the stent 14 may contract, and the balloon 13 may be tightened by the contraction of the stent 14, and the balloon 13 may be damaged or deformed. In this respect, the balloon 13 is pressed against the stent 14 while the expansion of the stent 14 is restricted so that the outer diameter of the stent 14 does not become larger than the outer diameter DS2 after the stent expansion. Since the stent 14 does not expand at times, the stent 14 does not contract even if the pressing on the stent 14 is stopped. As a result, it can be avoided that the balloon 13 is damaged due to the contraction of the stent 14.

  By applying a compressive force to the stent 14 from the outer peripheral side, the stent 14 is reduced in diameter and pressed onto the balloon 13 and a series of releasing steps for releasing the compressive force. The process was performed a plurality of times, and then the second crimping process was performed. When the stent 14 is reduced in diameter in the first crimping step and is crimped onto the balloon 13, the larger the amount of diameter reduction (the amount of diameter reduction), the larger the recoil of the stent 14 after release of the compression force is applied. The amount (degree) is considered to increase. In this regard, by performing the first crimping step (that is, reducing the diameter of the stent 14) a plurality of times as described above, the compression force is not applied as compared with the case where the diameter of the stent 14 is reduced only once. The amount of recoil of the stent 14 can be reduced. Thereby, in the second pressure-bonding step after releasing the compression force, the stent 14 can be pressure-bonded on the balloon 13 with the stent outer diameter DS2 as small as possible.

  When the stent 14 made of a cobalt chromium alloy was attached to the balloon 13, the above-described stent attachment step was applied. Since the stent 14 made of cobalt chromium alloy is rich in elasticity, even if the stent 14 is pressure-bonded on the balloon 13 by applying a compressive force to the stent 14 from the outer peripheral side, the application of the compressive force is subsequently released. In some cases, the stent 14 is likely to expand (recoil). In other words, it is difficult for this type of stent 14 to appropriately secure a holding force on the balloon 13. In view of this point, it can be said that the significance of applying the above-described stent attachment step when attaching the stent 14 onto the balloon 13 is great.

  In the first crimping step, the stent 14 is circumferentially moved relative to the balloon 13 (stent rotation) so that the rotation direction of the inner surface of the stent 14 with respect to the outer circumferential surface of the balloon 13 is the same as the winding direction of the wings 27 of the balloon 13. The stent 14 was crimped onto the balloon 13 while rotating in the direction). Thereby, when the stent 14 is pressure-bonded onto the balloon 13, it is possible to prevent the wings 27 of the balloon 13 from being damaged. For this reason, it can suppress that the outer diameter of the attachment part of the stent 14 becomes large, and can suppress that a passability falls as a result.

  More specifically, after the inner surface of the stent 14 comes into contact with the outer peripheral surface of the balloon 13 during the first pressure-bonding step, the inner surface of the stent 14 extends around the balloon 13 with respect to the outer peripheral surface of the balloon 13. The stent 14 was rotated in the circumferential direction (stent rotation direction) with respect to the balloon 13 so as to rotate 1/30. Here, for example, if the amount of rotation that the inner surface of the stent 14 rotates relative to the outer peripheral surface of the balloon 13 after the inner surface of the stent 14 contacts the outer peripheral surface of the balloon 13 is less than 1/100 rotation around the balloon 13, The effect of rotating the stent 14 around the balloon 13 cannot be obtained sufficiently, and there is a possibility that the wings 27 will be carelessly generated. Further, if the amount of rotation is larger than 1/30, the force in the stent rotation direction is applied to the wings 27 of the balloon 13 and the balloon 13 may be affected unexpectedly and the pressure resistance of the balloon 13 may be reduced. There is. In this regard, in the above-described configuration in which the rotation amount is 1/100 to 1/30 rotation, it is possible to suppress the swaying of the wings 27 without causing these disadvantages.

  In the above embodiment, the stent 14 is rotated with respect to the balloon 13 so that the rotation direction of the inner surface of the stent 14 with respect to the outer peripheral surface of the balloon 13 is the same direction as the winding direction of the wings 27. Conversely, the balloon 13 may be rotated relative to the stent 14. Further, both the balloon 13 and the stent 14 may be rotated. In short, as long as the rotation direction of the inner surface of the stent 14 with respect to the outer peripheral surface of the balloon 13 is the same as the winding direction of the wings 27, either the balloon 13 or the stent 14 may be rotated.

  The present invention is not limited to the above embodiment, and may be implemented as follows, for example.

  (1) In the above embodiment, the series of steps including the first crimping step and the release step is performed twice. However, the series of steps may be performed three times or more, or may be performed only once. Good.

  In addition, when performing a series of steps including the first crimping step and the releasing step a plurality of times, the crimping conditions in each first crimping step may be different, or the release times in each releasing step may be different. For example, in the above embodiment, it is conceivable that the compression positions of the pressing members 46 are different in the first first pressure-bonding process and the second first pressure-bonding process. That is, the compression position of each pressing member 46 in the first first pressure-bonding process is a position where the stent compression diameter DL is DL (first time), and the compression position of each pressing member 46 in the second first pressure-bonding process is the stent. When the compression diameter DL is set to a position where DL (second time) is set, DL (first time) <DL (second time) may be set, or DL (first time)> DL (second time) may be set. In short, if the outer diameter of the stent 14 becomes DS2 (target outer diameter DX) as a result of performing a series of processes including the first crimping process and the releasing process twice and then recoiling the stent 14, each first crimping is performed. The stent compression diameter DL in the process may be arbitrary.

  (2) In the above-described embodiment, the expansion of the stent 14 is regulated so that the outer diameter of the stent 14 does not become larger than the outer diameter DS2 of the stent 14 after releasing the compression force applied to the stent 14 in the second crimping step. However, this may be changed. For example, the target outer diameter DX of the stent 14 is set to a value larger than the stent outer diameter DS2 after the compression force is released, and the stent 14 is expanded so that the outer diameter of the stent 14 does not become larger than the target outer diameter DX. You may make it regulate. Even in such a case, the balloon 13 can be pressed against the stent 14 in a state in which expansion of the stent 14 to the outer side in the radial direction is restricted. Therefore, the pressing force of the balloon 13 against the stent 14 can be suitably exerted. it can.

  Further, in the second crimping process, the expansion restriction of the stent 14 to the radially outer side may not be performed. Even in that case, the stent 14 can be crimped onto the balloon 13 by pressing the balloon 13 against the stent 14.

  (3) In the said embodiment, although the 2nd crimping | compression-bonding process was performed only once, you may make it perform the same process in multiple times. For example, it is conceivable to perform a series of steps of a second pressure-bonding step and a pressure-reducing step of decompressing the balloon 13 after the second pressure-bonding step a plurality of times. It is considered that the pressing force of the balloon 13 against the stent 14 by pressurizing the balloon 13 becomes the largest when the pressure of the balloon 13 increases. In view of this point, pressing the balloon 13 against the stent 14 by repeating the pressurization and decompression of the balloon 13 a plurality of times as described above can be expected to increase the retention force of the stent 14 on the balloon 13. .

  (4) In the above embodiment, a rotating device in which a plurality of pressing members 46 rotates is used as the pressing device 41, but the plurality of pressing members 46 linearly move in the radial direction of the stent 14 (balloon 13). Other configurations such as a direct acting type may be used. In short, as long as the stent 14 can be crimped onto the balloon 13 by applying a compressive force to the stent 14 from the outer peripheral side by the pressing member 46, the configuration thereof is arbitrary.

(About other inventions extracted from the disclosure scope of this specification)
In the following, inventions that can be extracted in addition to the inventions described in the means column for solving the problems within the scope of disclosure of the present specification will be described while showing effects and the like as necessary.

A balloon catheter having an inner tube, and a balloon having a plurality of wings that are inflated or deflated using a fluid and wraps around the inner tube in a predetermined direction in a contracted state;
A stent mounted on the outer surface of each wing in the balloon;
In a method for producing a stent delivery catheter comprising:
A stent placement step of placing the stent on the outer peripheral side of the balloon;
A stent crimping step of shrinking the diameter of the stent by applying a compressive force directed radially outward from the outer peripheral side to the stent disposed in the placement step, and crimping the stent onto each wing of the balloon;
With
In the crimping step, while rotating at least one of the balloon and the stent so that the rotation direction of the inner surface of the stent with respect to the outer peripheral surface of the balloon is the same direction as the winding direction of the wing of the balloon A method for manufacturing a stent delivery catheter, wherein the stent is crimped onto each wing.

  Conventionally, when a stent is pressure-bonded onto each wing of a balloon, the wing of the balloon is inadvertently drawn, and the outer diameter of the stent mounting portion may be increased. In this case, we are anxious about the fall of passage nature. In this regard, with the above-described configuration, when the stent is pressure-bonded onto the balloon wing, it is possible to suppress the occurrence of the wing, and as a result, it is possible to suppress the outer diameter of the stent mounting portion from increasing. Can do. For this reason, a stent can be crimped | bonded on a balloon, suppressing the fall of passage property.

  DESCRIPTION OF SYMBOLS 10 ... Stent delivery catheter, 13 ... Balloon, 14 ... Stent, 20 ... Balloon catheter, 40 ... Stent attachment device, 41 ... Pressing device, 42 ... Pressing device, 43 ... Controller, 46 ... Pressing member, 50 ... Arrangement | positioning area | region.

Claims (4)

A balloon catheter having a balloon that is inflated or deflated using a fluid;
In a method for manufacturing a stent delivery catheter, comprising a stent attached on the outer peripheral surface of the balloon and expanded by expansion of the balloon,
An arrangement step of arranging the stent on the outer peripheral side of the balloon;
A first crimping step of reducing the diameter of the stent by applying a compressive force directed radially inward from the outer peripheral side to the stent disposed in the placement step, and crimping the stent onto the outer peripheral surface of the balloon;
A releasing step in which the stent is elastically deformed from a compressed state by releasing the application of the compressive force to the stent ; and
After the releasing step, fluid is supplied to the balloon to pressurize the balloon, and the pressurized balloon is pressed against the stent from the inner peripheral side, thereby pressing the stent onto the outer peripheral surface of the balloon. and a second bonding step,
In the second crimping step, the balloon is added while restricting the stent from expanding radially outward so that the outer diameter of the stent does not become larger than the outer diameter of the stent after being expanded in the releasing step. A method for manufacturing a stent delivery catheter, comprising: The stent delivery according to claim 1 , wherein the second crimping step is the last crimping step among a plurality of crimping steps including the first crimping step and the second crimping step. A method for manufacturing a catheter. 3. The method for manufacturing a stent delivery catheter according to claim 1, wherein the second crimping step is performed after a series of steps including the first crimping step and the releasing step are performed a plurality of times. Used when attaching a stent that is expanded by inflation of a balloon on the outer peripheral surface of the balloon that is inflated or deflated using a fluid in a balloon catheter;
A pressurizing device that pressurizes the balloon by supplying fluid to the balloon;
An arrangement region in which the balloon and the stent are arranged in a state where the stent is positioned on the outer peripheral side of the balloon, and the stent arranged in the arrangement region is radially inward from the outer peripheral side by a pressing member. A pressing device for applying a compressive force directed to,
A stent attachment device comprising:
A first pressure-bonding means for reducing the diameter of the stent and pressure-bonding the outer surface of the balloon by applying the compressive force to the stent by the pressing device;
A release means for elastically deforming the stent from a compressed state by releasing the application of compressive force to the stent by the pressing device; and
After releasing the application of the compressive force by the release means, the balloon is pressed by the pressurizing device so that the pressurized balloon is pressed against the stent from the inner peripheral side onto the outer peripheral surface of the balloon. A second crimping means for crimping the stent;
At the time of crimping by the second crimping means, after the outer diameter of the stent is expanded with the release of the compressive force by the releasing means, the pressing member is arranged on the outer peripheral side of the stent by the pressing device. And a restricting means for restricting the stent from expanding radially outward so that the stent does not become larger than the outer diameter of the stent.

Images