JP2013009704A - Method of manufacturing living organism dilator instrument and living organism dilator instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a living organism dilator instrument, which can properly be mounted with a stent on the surface of a balloon.SOLUTION: Firstly, a step of forming an inside tube 25 is performed by using polyimide. After that, a step of temporarily retaining a pair of angiography tubes 41, 42 at prescribed points of the inside tube 25 is performed. After that, a step of forming a coated tube 43 is performed. Concretely, a thermal contractive tube 44 is arranged so as to cover an external peripheral face of a prescribed range of the inside tube 25. Then, the thermal contractive tube 44 is heated by using a heater HD. By this, the thermal contractive tube 44 is contracted, and the coated tube 43 is formed so as to cover the external peripheral face of the prescribed range of the inside tube 25. After that, by performing a step of inserting an inside tube unit into an outside tube 24, a step of attaching the balloon 23, and a step of mounting the stent 11 on the contracted balloon 23, the manufacturing of the living organism dilator instrument 10 is completed.

Description

  The present invention relates to a method for manufacturing a living organ expanding device and a living organ expanding device that are used by being introduced into a living body, for example, when performing an expansion treatment of a stenosis site or a blocking site of a blood vessel.

  As a treatment method for expanding a stenosis site or an occlusion site in a living organ such as a blood vessel, a method is known in which a living organ dilator is inserted into the living organ and a stent is placed in the stenosis site or the occlusion site. There are various types of stents, and one of them is a balloon expandable stent. In this case, a balloon catheter is used to introduce the stent into a living body.

  Specifically, the stent is formed so as to enable transition between a contracted state and an expanded state by plastic deformation by processing a metal wire or a metal tube. And when the stent is inserted into the living body, it is in a contracted state so as to be in close contact with the surface of the contracted balloon from the outside, and after being placed at the treatment site, the stent receives the expansion force of the balloon from the inner peripheral side. , Plastic deformation to the expanded state. By being indwelled in the living body in this state, it is possible to maintain a state where the stenosis site or the occlusion site is expanded.

  Here, the performance required for the balloon catheter includes the ability to pass through stenosis and occlusions. One technique for satisfying such required performance is to make the distal end side of the balloon catheter thinner.

  However, when the distal end side of the balloon catheter is formed thin, the size of the balloon portion in the contracted state is also reduced accordingly. In this case, even if an attempt is made to mount a stent having a relatively large diameter on the balloon, the stent becomes difficult to adhere to the surface of the balloon, and there is a concern that the stent may be misaligned during introduction into the living body. There is a concern that such a large-diameter stent may not be mounted.

  On the other hand, for example, a method of forming a protrusion on the surface of the balloon and preventing the displacement of the stent by the protrusion as in Patent Document 1 is conceivable.

Special Table 2002-539888

  However, if it is attempted to prevent the displacement of the stent by only the protrusion as in Patent Document 1, it is necessary to form a protrusion having higher strength as the diameter of the stent used increases. If it does so, the manufacturing process of a balloon will become complicated, and we are anxious about the softness | flexibility of a balloon also falling significantly.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a living organ expanding device and a living organ expanding device capable of suitably mounting a stent on a balloon surface. .

  Hereinafter, means and the like effective for solving the above-described problems will be described while showing functions and effects as necessary.

  Method of manufacturing a living organ dilator: a balloon that is inflated or contracted using a fluid and expands by plastically deforming a stent mounted on a mounting region on an outer peripheral surface, and a distal end by the balloon In a method of manufacturing a living organ dilator having a tube body covered on a side, an axial direction with respect to at least a part of the mounting region of an outer peripheral surface of a base tube defining at least an inner peripheral surface of the tube body. A tube placement step of placing a heat-shrinkable tube so as to cover a predetermined outer peripheral surface including a surface at the same position from the outside, and heating the heat-shrinkable tube placed in the placement step to cause heat shrinkage A covering step of covering a predetermined outer peripheral surface with a covering tube, and the tube body including the covering tube is formed. To.

  According to this configuration, since the covering tube is provided in the base tube where the stent is mounted, the size of the mounting region can be increased while the distal end of the base tube is thin. It becomes possible. Thereby, it is possible to support a stent having a relatively large size in a stable state while improving the passability of a narrowed portion or a closed portion. Moreover, since the covering tube is formed using a heat-shrinkable tube, it is possible to facilitate the formation of the covering tube. In particular, the thickness of the base tube itself is not changed, but the configuration is such that the coated tube is stacked on the base tube, so the coated tube is formed when forming a device for mounting a relatively small stent. In this case, a covered tube may be formed when forming a device for mounting a relatively large stent. Therefore, it is possible to use a common base tube when the sizes of stents to be used are different.

  A living organ dilator according to the first aspect of the present invention: a living organ dilator produced by the above-described manufacturing method, wherein a surface of the outer peripheral surface of the base tube existing inside an inflated and deflated region of the balloon An annular member is provided so as to cover a part of the surface from the outside, and at least a part of the annular member is included in a range covered by the covering tube. According to this configuration, the annular member can be fixed to the base tube using the coated tube.

  An example of the annular member is a contrast ring. In this case, it is possible to fix the contrast ring to the base tube using the coated tube.

  Biological organ dilating instrument of the second invention: The living organ dilating instrument of the first invention is characterized in that at least one end of the annular member is included in a range covered by the covering tube. According to this configuration, since at least one end of the annular member is prevented from coming into direct contact with the deflated balloon, it is possible to protect the balloon using the coated tube.

  The living organ dilator according to the third invention: In the living organ dilator according to the second invention, a step following the step between the annular member and the outer peripheral surface of the base tube is formed on the outer peripheral surface of the coated tube. It is characterized by having occurred. According to this configuration, in the configuration in which the balloon is protected by covering one end of the annular member with the covering tube, a step is generated on the outer peripheral surface of the covering portion. It can also be used for stable support.

  A living organ dilating instrument according to a fourth aspect of the invention: In the living organ dilating instrument according to the third aspect of the invention, the step formed on the outer peripheral surface of the coated tube is outside in a predetermined direction with respect to the mounting region in the axial direction. And a component facing in a direction opposite to the predetermined direction is included in the direction in which the step is directed. According to this configuration, it is expected that the displacement of the stent in the axial direction is regulated by the step, and even the suppression of the displacement of the stent can be performed using the coated tube.

  The living organ dilating instrument of the fifth invention: In the living organ dilating instrument of the first invention, a part of the outer peripheral surface of the base tube existing inside the inflation and deflation region of the balloon is a part of the surface. An annular member different from the annular member is provided so as to cover from the outside, and one annular member of the annular members is present on the proximal side of the mounting region in the axial direction. The other annular member is present on the distal side of the mounting region in the axial direction, and the distal end of the one annular member and the other annular member are within the range covered by the covering tube. And a step which follows the step between each annular member and the outer peripheral surface of the base tube is formed on the outer peripheral surface of the covering tube. According to this structure, it becomes possible to fix a some annular member to a base tube using a covering tube. Further, the plurality of annular members are arranged so as to sandwich the mounting region of the stent, and at least ends facing the annular members are covered with the covering tube, and the outer peripheral surface of the covering tube includes these end portions. There is a step corresponding to. Thereby, it becomes possible to suppress the displacement of both the distal side and the proximal side of the stent using the configuration of each annular member and the covering tube.

  A living organ dilator according to a sixth aspect of the invention: a living organ dilator manufactured by the above manufacturing method, characterized in that a joint portion of the balloon is not included in a range covered by the covering tube. . According to this configuration, it is possible to provide the covering tube while preventing a portion where the rigidity is extremely increased from being generated.

(A) It is the living body organ expansion instrument in 1st Embodiment, Comprising: It is a balloon of the expansion | swelling state which shows a stent, a balloon, and an outer tube in the state of a longitudinal cross-section, and its periphery side view, (b) Stent, balloon FIG. 2 is a side view of the balloon in a contracted state showing the outer tube in the state of the longitudinal section and the periphery thereof, and (c) is a longitudinal sectional view showing a part of the inner tube and the periphery thereof in an enlarged manner, and FIG. It is AA sectional view taken on the line of (b). (A)-(e) It is a figure for demonstrating the manufacturing method of a biological organ expansion instrument. It is a schematic whole side view which shows the structure of a biological organ expansion instrument. It is a living organ expansion device in a 2nd embodiment, and is a side view of the balloon of the contracted state which shows a stent, a balloon, and an outer tube in the state of a longitudinal section, and its circumference. (A) It is a living organ expansion device in 3rd Embodiment, Comprising: It is a balloon of the expansion | swelling state which shows a stent, a balloon, and an outer tube in the state of a longitudinal section, and its periphery side view, (b) Stent, balloon FIG. 3 is a side view of the balloon in the contracted state and the periphery thereof, showing the outer tube in a longitudinal cross-sectional state.

(First embodiment)
A first embodiment of a living organ dilator will be described with reference to the drawings. First, a schematic configuration of the living organ dilator 10 will be described with reference to FIG. FIG. 3 is a schematic overall side view showing the configuration of the living organ dilator 10.

  The living organ dilator 10 includes a stent 11 and a balloon catheter 20. In the stent 11, the transition between the contracted state and the expanded state is performed by plastic deformation. The stent 11 is formed in a tubular shape using a linear element, and a plurality of hole portions penetrating inward and outward are formed at intermediate positions in the axial direction. The material for forming the stent 11 is arbitrary, and examples thereof include metals such as stainless steel and biodegradable resins such as polylactic acid. Moreover, the chemical | medical agent may be provided to the surface of the metal stent or the surface of the resin stent. The stent 11 is deflated on the surface of the balloon 23 of the balloon catheter 20 and mounted on the balloon 23, and the balloon 23 is inflated and subjected to an external force directed radially outward by the balloon 23. It transforms and transitions to the expanded state.

  Hereinafter, the balloon catheter 20 will be described in detail.

  As shown in FIG. 3, the balloon catheter 20 includes a catheter tube 21, a hub 22 attached to a proximal end portion (base end portion) of the catheter tube 21, and a distal end side (tip side) of the catheter tube 21. ) Attached to the balloon 23. The length of the balloon catheter 20 is 1 m to 2 m.

  The catheter tube 21 is composed of a plurality of tubes, and has an inner and outer multiple tube structure at least from the midway position in the axial direction (longitudinal direction) to the position of the balloon 23. Specifically, the catheter tube 21 includes an outer tube 24 having the proximal end connected to the hub 22 and an inner tube 25 having a diameter smaller than that of the outer tube 24. The inner tube 25 is inserted into the outer tube 24, and its proximal end is joined to an intermediate position in the axial direction of the outer tube 24 and extends further to the distal side than the outer tube 24. Is provided. A balloon 23 is provided so as to cover the extended region from the outside.

  The outer tube 24, the inner tube 25, and the balloon 23 will be described below. In the following description, FIG. 1 will be referred to as appropriate in addition to FIG.

  FIG. 1A is a side view showing the balloon 23 and its surroundings when the balloon 23 is in an inflated state, and FIG. 1B shows the balloon 23 and its surroundings when the balloon 23 is in a deflated state. FIG. In FIGS. 1A and 1B, the stent 11, the balloon 23, and the outer tube 24 are shown in a vertical cross-sectional state. Moreover, FIG.1 (c) is a longitudinal cross-sectional view which expands and shows a part of inner tube 25, and its periphery, FIG.1 (d) is the sectional view on the AA line of FIG.1 (b).

  The outer tube 24 is formed in a tubular shape having outer tube holes 24a (see FIG. 1A) that are continuous over the entire axial direction and open at both ends. The outer tube hole 24a functions as a fluid lumen through which the compressed fluid flows when the balloon 23 is inflated or deflated. The compressed fluid is supplied and sucked by a fluid device (not shown) connected to the hub 22.

  As shown in FIG. 3, the outer tube 24 is an outer proximal tube 24 b in which a predetermined range from the position continuous to the hub 22 toward the distal side is formed of a metal such as a Ni—Ti alloy. The distal side is an outer distal tube 24c formed of thermoplastic polyamide so that the rigidity is lower than that of the outer proximal tube 24b. However, the present invention is not limited to this, and the outer proximal tube 24b may be formed of a synthetic resin.

  In this specification, the term “rigidity” refers to the magnitude of a moment that acts when the catheter is bent in a direction perpendicular to the axial direction.

  The inner tube 25 is formed in a tubular shape having inner tube holes 25a (see FIGS. 1A to 1D) that are continuous over the entire axial direction and open at both ends. The inner tube hole 25a functions as a wire lumen through which a guide wire G used for insertion of the balloon catheter 20 into the living body is inserted.

  The inner tube 25 is formed using a resin material. Examples of the resin material include polyethylene, polyethylene terephthalate, polypropylene, polyurethane, polyamide, polyamide elastomer, polyimide, polyamide imide, polyether ether ketone, polyimide elastomer, silicon rubber, and the like, and these may be used alone. A combination of more than one type may be used.

  Here, the inner tube 25 needs to advance in the living body while supporting the stent 11 mounted on the balloon 23. In order to stabilize the support, the strength in the tensile direction and the radial direction should be improved. Is preferred. In order to improve the strength, a method of embedding a reinforcing layer such as a metal braided tube or coil in the resin layer can be considered, but besides that, at least a portion where the stent 11 is mounted in the inner tube 25, A method of forming using a material having a high Shore hardness such as polyimide and polyamideimide can be considered. In this case, polyimide is more preferable.

  In addition, at least a portion where the stent 11 is mounted in the inner tube 25 may be formed of only the material having the high Shore hardness, for example, only of polyimide, but may be formed of a plurality of materials. For example, the inner layer that defines the inner peripheral surface of the inner tube 25 is formed of polyimide, and the outer layer that defines the outer peripheral surface of the inner tube 25 is a material having a Shore hardness lower than that of the polyimide, for example, a polyamide such as Pebax (registered trademark). A configuration formed by an elastomer is conceivable.

  In order to reduce the sliding resistance between the inner tube 25 and the guide wire G, at least the inner peripheral surface of the inner tube 25 is formed using a polymer alloyed material using polyimide and a fluorine-based resin. It may be. In this case, examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), polychlorofluoroethylene, perfluoroalkoxyalkane, ethylene-tetrafluoroethylene copolymer, etc. Among these, PTFE is preferable. The polymer alloy includes a polymer blend, block copolymerization, graft copolymerization, and IPN (Interpenetrating Polymer Network), and the polymer blend is preferable in view of ease of design.

  As this polymer blend, a blend material of polyimide and polytetrafluoroethylene (PTFE) is preferable. In this case, it is possible to generate smooth surface characteristics with a small friction coefficient, which is a characteristic of PTFE, while the basic material properties are the same as those of polyimide. In addition, the blend ratio of the blend material is preferably 97: 3 to 50:50, and more preferably 80:20, in terms of wt% of polyimide: PTFE.

  When using a polymer alloyed material as described above, an inner layer that defines the inner peripheral surface of the inner tube 25 is formed from the polymer alloyed material, and an outer layer that defines the outer peripheral surface of the inner tube 25 is the polymer. You may form by the material whose Shore hardness is lower than the alloyed material, for example, polyamide elastomers, such as Pebax. In this case, the sliding resistance can be reduced as described above while making the outer peripheral surface side flexible. Further, for example, the inner layer that defines the inner peripheral surface of the inner tube 25 may be formed of the above polymer alloyed material, and the outer layer that defines the outer peripheral surface of the inner tube 25 may be formed of polyimide. In this case, the sliding resistance can be reduced as described above while improving the strength of the inner tube 25. In addition, when producing an inner layer and an outer layer as mentioned above, the thickness ratio of an inner layer and an outer layer has preferable 5: 5-7: 3.

  The inner layer is made of the fluororesin, and includes a first inner layer that defines the inner peripheral surface of the inner tube 25, and is laminated on the first inner layer, and the material having a high Shore hardness and the fluororesin. You may form with the 2nd inner layer formed from a polymer alloy.

  The inner tube 25 may be formed by connecting a plurality of tubes in the axial direction. In this case, it is preferable that at least a portion on which the stent 11 is mounted is formed using the material as described above. However, in view of facilitating the formation of the inner tube 25, it is preferably formed of a single tube. Even in this case, it is preferable that the strength of the inner tube 25 is improved by using the above materials. Note that the portion of the inner tube 25 that extends further to the distal side than the balloon 23 is tapered such that the outer diameter gradually decreases toward the distal end.

  The balloon 23 is formed of a thermoplastic polyamide elastomer such as Pebax. However, it is not limited to this, and is formed of other resin materials such as polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyimide, polyimide elastomer, polyurethane, polyurethane elastomer, polyethylene terephthalate, silicon rubber, styrene olefin rubber, etc. May be. Moreover, you may form with the material which mixed 2 or more types among the resin material 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 manufacturing method of the balloon 23 is not particularly limited, and examples thereof include blow molding, dipping molding, and extrusion molding. However, when the stenosis occurring in the coronary artery of the heart is expanded and treated, it is preferable that the balloon 23 has sufficient pressure resistance, and in this case, blow molding is preferable.

  As shown in FIG. 1A, the balloon 23 is formed so that the inner diameter and the outer diameter are changed in a plurality of stages in the inflated state. That is, the balloon 23 includes a proximal-side joining region 31 joined to the outer tube 24, a proximal-side transition region 32 having a tapered shape so that the inner diameter and the outer diameter are increased toward the distal end side, and a long length. An inflating region 33 having the same inner diameter and outer diameter in the entire length direction and forming the maximum outer diameter region of the balloon 23, and a tapered shape so that the inner diameter and the outer diameter are reduced toward the distal end side. A distal transition region 34 and a distal joining region 35 joined to the inner tube 25 are provided in this order from the proximal side. In this case, in the configuration in which the inner tube 25 is formed using polyimide and the balloon 23 is formed using a polyamide elastomer such as Pebax, the distal bonding region 35 is an adhesive with respect to the inner tube 25. It is preferable to join using.

  The balloon 23 is formed of a plurality of blades (specifically, three blades), and as shown in FIG. 1 (d), when the balloon 23 is in a contracted state, each of the blades 23a to 23c is individually connected to the inner tube. It will be in the state wound around 25. Specifically, when the balloon 23 is changed from the inflated state to the deflated state, the balloon 23 is inflated and deflated (proximal side) so that a plurality of wings 23a to 23c standing perpendicular to the axial direction are formed at equal intervals. The transition region 32, the expansion region 33, and the distal transition region 34) are folded, and then each wing 23a-23c wraps around the inner tube 25 and enters a contracted state. The stent 11 is mounted on the balloon 23 in the wound state. The number of wings of the balloon 23 in the contracted state is not limited to three, and may be two, four, five, or six.

  In this case, as shown in FIGS. 1A and 1B, the stent 11 is mounted on the expansion region 33 among the regions 31 to 35 of the balloon 23. That is, the expansion region 33 of the balloon 23 has a larger length in the axial direction than the stent 11 used, and both ends of the stent 11 are closer to the center in the axial direction than both ends of the expansion region 33. Existing.

  In the configuration in which the stent 11 is mounted on the balloon 23, the inner tube 25 has a pair of contrast rings 41 and 42 so that the range in which the stent 11 is mounted can be visually confirmed from outside the living body under X-ray projection. Is provided. These contrast rings 41 and 42 are made of metal and formed in a cylindrical shape. In detail, the forming material is formed of stainless steel, but is not limited thereto, and may be formed of gold, platinum, iridium, cobalt chromium alloy, titanium, or the like.

  The position where the pair of contrast rings 41 and 42 are arranged will be described in detail. Among the pair of contrast rings 41 and 42, the first contrast ring 41 includes the proximal transition region 32 and the inflation region of the balloon 23 in the axial direction. It is arranged at a position near the boundary with 33. The second contrast ring 42 of the pair of contrast rings 41 and 42 is disposed at a position near the boundary between the inflation region 33 and the distal transition region 34 of the balloon 23 in the axial direction. In more detail about these positions, the first contrast ring 41 has a proximal end portion positioned in the vicinity of the boundary between the proximal transition region 32 and the expansion region 33 in the axial direction. The distal end portion 42 is positioned near the boundary between the expansion region 33 and the distal transition region 34 in the axial direction.

  The first contrast ring 41 and the second contrast ring 42 are spaced apart in the axial direction, and the distance between the contrast rings 41 and 42 is slightly larger than the axial length of the stent 11 to be used. It has become. Therefore, as shown in FIG. 1B, when the stent 11 is mounted on the deflated balloon 23, one end of the stent 11 is present on the distal side of the first contrast ring 41, One end of the opposite side of the stent 11 is present on the proximal side of the second contrast ring 42.

  Next, a configuration for supporting the stent 11 in a stable state on the balloon 23 will be described.

  As shown in FIG. 1 (a), a covering tube 43 is provided in the inner tube 25 in a region existing inside the expansion and contraction region of the balloon 23 so as to cover the outer peripheral surface of the inner tube 25. Yes. The covering tube 43 is a tube using a resin material, and is formed using a heat shrinkable tube.

  A heat-shrinkable tube is a tube that shrinks at least in the radial direction when heated. For example, a tube is formed by extrusion using a predetermined resin, and then crosslinked using an electron beam or radiation. And the tube is further extended outward in the radial direction. The heat-shrinkable tube retains the stretched state near room temperature, but shrinks in the radial direction when heated.

  Specifically, a polyamide elastomer such as Pebax is used as a material for forming the covering tube 43. However, the present invention is not limited to this, and is formed using a fluorine resin such as polyvinylidene fluoride or perfluoroalkoxy fluorine resin, an elastomer of the fluorine resin, polyolefin, polyester elastomer, ethylene-propylene rubber, silicon rubber, or the like. May be.

  The covering tube 43 extends so as to include the entire range in which the stent 11 can be mounted in the axial direction. Specifically, the proximal end portion of the coated tube 43 is present on the proximal side of the first contrast ring 41 that is present on the proximal side of the pair of contrast rings 41 and 42. The distal end of the second contrast ring 41 is located more distal than the second contrast ring 42 present on the distal side of the pair of contrast rings 41 and 42. However, the proximal end portion of the covering tube 43 exists on the distal side of the proximal side joining region 31 of the balloon 23, and the distal end portion of the covering tube 43 is located on the distal side joining region 35 of the balloon 23. Is also present on the proximal side. Thereby, the covering tube 43 can be provided without increasing the rigidity of the portion where the balloon 23 is joined.

  Due to the provision of the covering tube 43, as shown in FIG. 1D, the wings 23 a to 23 c of the deflated balloon 23 are wound around the outer peripheral surface of the covering tube 43 at the place where the stent 11 is mounted. It will be in a connected state. Therefore, the outer diameter of the balloon 23 at the place where the stent 11 is mounted can be increased. Therefore, even the stent 11 having a relatively large diameter can be brought into close contact with the deflated balloon 23 from the outside, and the stent 11 can be supported in a stable state.

  The hardness of the material forming the coated tube 43 is preferably a Shore hardness of 25D to 72D, and more preferably 25D to 55D. By using a material having such hardness, it is possible to stabilize the support of the stent 11 while suppressing the rigidity of the portion where the covering tube 43 is provided from becoming extremely high.

  The wall thickness of the coated tube 43 varies depending on the diameter of the stent 11 to be used. When the outer diameter of the inner tube 25 is 0.4 mm to 0.5 mm, the outer diameter of the inner tube 25 is changed. On the other hand, a thickness that increases the outer diameter by 10% to 40% is preferable, and a thickness that increases the outer diameter by 15% to 30% is more preferable. With such a thickness, it is possible to stabilize the support of the stent 11 while suppressing the rigidity of the portion where the covering tube 43 is provided from becoming extremely high. More specifically, for example, when the outer diameter of the inner tube 25 is 0.4 mm, a configuration in which the thickness of the coated tube 43 is 0.05 mm can be mentioned.

  In providing the coated tube 43 while improving the passage of the balloon catheter 20 at a stenosis or occlusion in a blood vessel or the like, the thickness of the coated tube 43 is in a contracted state as shown in FIG. It is preferable that the maximum outer diameter of the inflation region 33 in the balloon 23 is set to be equal to or smaller than the outer diameter of the distal end portion of the outer tube 24. More preferably, the thickness of the covering tube 43 is set so that the maximum outer diameter of the stent 11 mounted on the balloon 23 in the contracted state is equal to or smaller than the outer diameter of the outer tube 24.

  Here, as already described, the covering tube 43 covers the pair of contrast rings 41 and 42 from the outside. That is, as shown in FIG. 1C, the pair of contrast rings 41 and 42 are provided so as to cover the outer peripheral surface of the inner tube 25, but the entire pair of contrast rings 41 and 42 are viewed from the outside. A covering tube 43 is provided so as to cover it. As a result, the contrast rings 41 and 42 can be fixed to the inner tube 25 using the covering tube 43. In addition, since the edge portions of the contrast rings 41 and 42 are also covered with the covering tube 43, the contracted balloon 23 is prevented from directly contacting the edge portions of the contrast rings 41 and 42. Note that an adhesive layer used to temporarily fix the contrast rings 41 and 42 to the inner tube 25 exists between the outer peripheral surface of the inner tube 25 and the contrast rings 41 and 42.

  At the place where the covering tube 43 is provided, the outer diameter of the inner tube unit (including the inner tube 25, the covering tube 43 and the contrast rings 41 and 42) is constant between the pair of contrast rings 41 and 42. On the other hand, the area where the contrast rings 41 and 42 are provided is larger than the surrounding area. That is, a step following the step between the contrast rings 41 and 42 and the outer peripheral surface of the inner tube 25 is formed on the outer peripheral surface of the coated tube 43. The direction of the step corresponding to the distal end portion of the first contrast ring 41 includes a component facing the distal side, and the direction of the step corresponding to the proximal end portion of the second contrast ring 42 Contains a component facing proximally. Accordingly, as shown in FIG. 1 (b), even when the covering tube 43 is provided, the outer peripheral surface of the balloon 23 in a wound state at the position where the pair of contrast rings 41 and 42 are provided. It is possible to protrude slightly outward, and it is possible to suppress the displacement of the stent 11 in the axial direction due to the protruding portion.

  Next, a method for manufacturing the living organ dilator 10 will be described with reference to FIG. 2A to 2E are views for explaining a method of manufacturing the living organ dilator 10. The case where the inner tube 25 is formed as a single tube made of polyimide will be described as an example.

  As shown in FIG. 2A, first, a step of forming the inner tube 25 using polyimide is performed. Although the distal end portion of the inner tube 25 is tapered in the forming step, the step of tapering may be performed after the balloon 23 is mounted.

  Thereafter, as shown in FIG. 2B, a step of temporarily fixing the pair of contrast rings 41 and 42 to a predetermined portion of the inner tube 25 is performed. Specifically, the pair of contrast rings 41 and 42 are temporarily fixed to the inner tube 25 using an adhesive.

  Thereafter, as shown in FIG. 2C, a forming step of the covering tube 43 is performed. Specifically, the heat-shrinkable tube 44 formed using Pebax having a Shore hardness of 55D is disposed so as to cover a predetermined range of the outer peripheral surface of the inner tube 25. In this case, the pair of contrast rings 41 and 42 are both included in the range covered by the heat shrinkable tube 44. Then, the heat shrinkable tube 44 is heated using the heating device HD. As a result, the heat-shrinkable tube 44 contracts, and as shown in FIG. 2D, the covering tube 43 is formed so as to cover a predetermined range of the outer peripheral surface of the inner tube 25.

  Thereafter, the step of inserting the inner tube unit into the outer tube 24, the step of mounting the balloon 23, and the step of mounting the stent 11 on the deflated balloon 23 are performed as shown in FIG. In addition, the production of the living organ dilator 10 is completed.

  Next, a method of using the living organ dilator 10 will be briefly described.

  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 living organ dilator 10 and introduced from the coronary artery entrance to the peripheral site through the occlusion or stenosis. Subsequently, the biological organ dilator 10 is inserted along the guide wire G to the occlusion site or the stenosis site while performing a push-pull operation.

  Thereafter, by injecting a compressed fluid into the balloon 23 from the hub 22 side using a pressurizer, the balloon 23 is inflated to expand the blockage or stenosis. Thereby, the stent 11 in a contracted state is plastically deformed to be in an expanded state. Thereafter, the compressed fluid injected into the balloon 23 is aspirated and extracted, whereby the balloon 23 is deflated, and the balloon catheter 20 is extracted from the body.

  The biological organ dilator 10 is mainly passed through a blood vessel as described above and used to treat blood vessels such as coronary artery, femoral artery, and pulmonary artery. It can also be applied to “tubes” and “body cavities” in vivo.

  According to the embodiment described in detail above, the following excellent effects are obtained.

  By providing the covering tube 43 at the site where the stent 11 is mounted in the inner tube 25, the outer diameter of the mounting site can be increased while the distal end of the inner tube 25 is thin. It becomes possible. As a result, the stent 11 having a relatively large diameter is supported in a stable state while improving the passability of the stenosis or occlusion and improving the followability to the guide wire G or the bent blood vessel. Is possible.

  Moreover, since the covering tube 43 is formed using a heat-shrinkable tube, it is possible to facilitate the formation of the covering tube 43. In particular, since the inner tube 25 itself is not configured to change its thickness, but the coated tube 43 is stacked on the inner tube 25, the balloon catheter 20 for mounting the stent 11 having a relatively small diameter is formed. At this time, the covered tube 43 is not formed, and the covered tube 43 may be formed when forming the balloon catheter 20 for mounting the stent 11 having a relatively large diameter. It is possible to use the common inner tube 25 when the sizes are different.

(Second Embodiment)
FIG. 4 is a side view showing the distal end side of the living organ dilating instrument 50 in the second embodiment, and is a view showing the stent 11, the outer tube 24, and the balloon 23 in a state of a longitudinal section. In FIG. 4, the same components as those in the above-described living organ dilator 10 are denoted by the same reference numerals, and the description of the components is basically omitted in the following description.

  As shown in FIG. 4, the inner tube 25 of the living organ dilator 50 is also provided with a pair of contrast rings 41 and 42 and a covering tube 43. However, on the outer peripheral surface of the deflated balloon 23, a first step surface 51 having a component facing the distal side is generated at a position corresponding to the distal end portion of the first contrast ring 41 existing on the proximal side. The second step surface 52 having a component facing the proximal side is generated at a position corresponding to the proximal end portion of the second contrast ring 42 existing on the distal side. Thereby, the first step surface 51 faces from the proximal side at a position close to the proximal end surface of the stent 11 mounted on the balloon 23 in the contracted state, and the distal end surface of the stent 11 The second step surface 52 is opposed to the distal side at a position close to the front. Therefore, even if the stent 11 tries to be displaced in the axial direction, it can be prevented.

(Third embodiment)
FIG. 5 is a side view showing the distal end side of the biological organ dilating instrument 60 in the third embodiment, and is a view showing the stent 11, the outer tube 24, and the balloon 23 in a longitudinal cross-sectional state. 5A shows a case where the balloon 23 is in an inflated state, and FIG. 5B shows a case where the balloon 23 is in a deflated state. Further, in FIG. 5, the same components as those of the living organ dilator 10 are denoted by the same reference numerals, and the description of the components is basically omitted in the following description.

  As shown in FIGS. 5A and 5B, the inner tube 25 of the living organ dilator 60 is also provided with a pair of contrast rings 41 and 42 and a covered tube 43. . However, the proximal end portion of the coated tube 43 exists on the distal side of the first contrast ring 41 existing on the proximal side, and the distal end portion of the coated tube 43 exists on the distal side. It exists in the proximal side rather than the 2 contrast ring 42, and the covering tube 43 is spaced apart to each contrast ring 41 and 42 in the axial direction. Therefore, the pair of contrast rings 41 and 42 are not covered with the covering tube 43.

  Further, the outer diameter of the covering tube 43 is the same as or substantially the same as the outer diameter of the contrast rings 41 and 42. In addition, the length of the covering tube 43 in the axial direction is smaller than that of the inflating region 33 in the balloon 23, and the length in the axial direction is smaller than the length of the stent 11. Therefore, the covering tube 43 does not exist over the entire portion where the stent 11 is mounted, but exists only in a part of the portion.

  According to this configuration, since the contrast rings 41 and 42 are not covered by the covering tube 43, it is possible to make the outer diameter of the portion where the balloon 23 is provided smaller than that of the biological organ dilator 10. .

(Other embodiments)
The present invention is not limited to the description of the above embodiment, and may be implemented as follows, for example.

  (1) In the first and second embodiments, the pair of contrast rings 41 and 42 may be temporarily fixed by caulking. However, since these contrast rings 41 and 42 are entirely covered with the covering tube 43, the caulking does not need to be performed firmly. When the covering tube 43 is formed by heat-shrinking the heat-shrinkable tube 44. It is sufficient if the contrast rings 41 and 42 are not misaligned.

  (2) In the first and second embodiments, the contrast rings 41 and 42 are discontinuous in an annular shape by forming slits in the cylindrical contrast rings 41 and 42 that are continuous over both ends in the axial direction. In addition, the inner diameter of the contrast rings 41 and 42 in the natural state may be slightly smaller than the outer diameter of the inner tube 25. In this case, in a state where the contrast rings 41 and 42 are arranged at predetermined positions of the inner tube 25, the contrast rings 41 and 42 are elastically deformed so as to be expanded in the radial direction, and are temporarily fixed to the inner tube 25 by the biasing force. It is possible to achieve a state that has been made. Even in this case, since the whole is covered with the covering tube 43, the contrast rings 41 and 42 can be firmly fixed.

  (3) In the first and second embodiments, the contrast rings 41 and 42 may not be temporarily fixed. Even in this case, since the contrast rings 41 and 42 are entirely covered with the covering tube 43, the contrast rings 41 and 42 can be firmly fixed.

  (4) In the first and second embodiments, a part of the contrast rings 41 and 42 may be covered with the covering tube 43. In this case, it is possible to fix the contrast rings 41 and 42 to the inner tube 25 using at least the coated tube 43. Further, only one end of the contrast rings 41 and 42 may be covered with the covering tube 43, and in this case, it is possible to prevent the one end from directly contacting the balloon 23. In addition, the one end side is a side close to the mounting region of the stent 11 and a step following the step between the contrast rings 41 and 42 and the inner tube 25 is formed on the outer peripheral surface of the covering portion, thereby the covering tube 43. It is possible to suppress the displacement of the stent 11 using

  (5) In each of the above embodiments, only one contrast ring may be provided in the region where the stent 11 is mounted, or three or more may be provided. In this case, in a configuration in which only one contrast ring is provided, the contrast ring may be provided on the proximal side of the mounting region of the stent 11 or may be provided on the distal side. Even in this configuration, at least the end on the mounting region side of the contrast ring is covered with the covering tube 43 and a step following the step between the contrast ring and the inner tube 25 is generated on the outer peripheral surface of the covering portion. By doing so, it is possible to suppress displacement of the stent 11 in at least one direction.

  In addition, one contrast ring or a plurality of contrast rings may be provided so as to be located at an intermediate position in the axial direction of the mounting region. Even in this case, the stent 11 is formed by covering at least one end of the contrast ring with the covering tube 43 and forming a step following the step between the contrast ring and the inner tube 25 on the outer peripheral surface of the covering portion. It is expected that a step following the step is generated in the stent 11 when the stent is in a contracted state on the balloon 23, and in this case, the displacement of the stent 11 in the axial direction is expected to be regulated at the step. Is done.

  Further, in the configuration in which the contrast ring is present at an intermediate position in the axial direction of the mounting region as described above, a plurality of covered tubes may be provided so as to sandwich the contrast ring. In this case, each of the coated tubes is provided so as not to cover the contrast ring from the outside, and the contrast ring and the coated tube are used by making the outer diameter of the contrast ring and the outer diameter of each coated tube the same or substantially the same. Thus, the radial expansion of the mounting area can be realized.

  (6) When attention is paid to the fact that a step is generated on the outer peripheral surface of the coated tube 43, the member for generating the step is not limited to the contrast rings 41 and 42, and has a predetermined thickness. Any member that creates a step between the outer peripheral surface of the inner tube 25 is optional.

  (7) In the third embodiment, the end of the covering tube 43 may be in contact with the end of the contrast rings 41 and 42 while not covering the contrast rings 41 and 42 at all. Further, in the range where the contrast rings 41 and 42 are not covered at all, the length of the coated tube 43 in the axial direction is set to be equal to or larger than the size of the stent 11, thereby covering the entire portion where the stent 11 is mounted. 43 may exist.

  DESCRIPTION OF SYMBOLS 10 ... Living organ expansion device, 11 ... Stent, 20 ... Balloon catheter, 21 ... Catheter tube, 23 ... Balloon, 25 ... Inner tube, 41 ... 1st contrast ring, 42 ... 2nd contrast ring, 43 ... Coated tube, 44 ... heat-shrinkable tube, 50 ... living organ dilator, 60 ... living organ dilator.

Claims (8)

A balloon which is expanded or contracted using a fluid and which expands by deforming a stent mounted on a mounting region on an outer peripheral surface by plastic deformation; and a tube body whose distal end side is covered by the balloon. In a method of manufacturing a living organ dilator having:
Of the outer peripheral surface of the base tube that defines at least the inner peripheral surface of the tube body, so as to cover from the outside a predetermined outer peripheral surface including a surface that is at the same position in the axial direction with respect to at least a part of the mounting region, A tube placement step of placing a heat shrinkable tube;
A coating step of coating the predetermined outer peripheral surface with a coating tube by heating and heat-shrinking the heat-shrinkable tube arranged in the arrangement step;
With
A method of manufacturing a living organ dilator comprising the tube body including the coated tube. A biological organ dilator produced by the production method according to claim 1,
Of the outer peripheral surface of the base tube, the surface existing inside the balloon expansion and contraction region is provided with an annular member so as to cover a part of the surface from the outside,
A living organ dilating instrument, wherein at least a part of the annular member is included in a range covered by the covering tube.   The living organ dilator according to claim 2, wherein at least one end of the annular member is included in a range covered by the covering tube.   The living organ dilator according to claim 3, wherein a step following the step between the annular member and the outer peripheral surface of the base tube is formed on the outer peripheral surface of the coated tube.   The step formed on the outer peripheral surface of the coated tube exists at a position that is outside in one predetermined direction with respect to the mounting region in the axial direction, and the predetermined one direction is in the direction in which the step is directed. The living organ dilator according to claim 4, wherein a component facing in the opposite direction is included. Of the outer peripheral surface of the base tube, the surface existing inside the balloon expansion and contraction region is provided with an annular member different from the annular member so as to cover a part of the surface from the outside. ,
One of the annular members is present on the proximal side of the mounting region in the axial direction, and the other annular member is located on the distal side of the mounting region in the axial direction. ,
The range covered by the covering tube includes the distal end portion of the one annular member and the proximal end portion of the other annular member, and the outer peripheral surface of the covering tube includes the annular portions. The living organ dilator according to claim 2, wherein a step following the step between the member and the outer peripheral surface of the base tube is generated.   The living organ dilator according to any one of claims 2 to 6, wherein the annular member is a contrast ring. A biological organ dilator produced by the production method according to claim 1,
A living organ dilating instrument characterized in that a joint portion of the balloon is not included in a range covered by the covering tube.

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