JP5769992B2 - catheter - Google Patents

Description

  The present invention relates to a catheter used by being introduced into a living body.

  A catheter is a hollow medical device that is inserted into a body cavity, tube, blood vessel or the like. The catheter is used in various applications. For example, a balloon catheter used for securing a passage of a blood vessel in an occluded state or a stenotic state, a catheter for delivering a stent used for securing the passage, and used for penetrating an obstruction site or a stenosis site. There are known catheters, suction catheters used for sucking thrombus, injection catheters used for injection of angiographic agents, guiding catheters used to introduce these catheters to target locations, etc. .

  As performance required to improve the operability of the catheter, for example, as shown in Patent Document 1, the followability with respect to a thin peripheral blood vessel having many branches and bending in a complicated manner, and pushing in when introducing the catheter to the target location Examples thereof include force transmission and kink resistance that prevents the catheter from being bent during the pushing operation.

  On the other hand, in Patent Document 1, in the configuration in which the distal catheter shaft and the proximal catheter shaft are connected in the axial direction, a spiral slit or the like is provided at the distal end portion of the proximal catheter shaft. A configuration is described in which the rigidity of the distal end portion is reduced by forming the distal end portion and the distal end portion having the reduced rigidity is inserted into the catheter shaft on the distal end side.

JP 2002-253678 A

  Here, since the configuration described in Patent Document 1 is based on a plurality of catheter shafts, it cannot be a countermeasure for a single catheter shaft. Furthermore, the configuration uses a plurality of catheter shafts. Even so, it is necessary to further improve each of the above performances.

  This invention is made | formed in view of the said situation, and it aims at providing the catheter which can aim at the improvement of operativity suitably.

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

1st invention catheter: It forms a catheter wall part, It comprises the catheter body which has a change object layer from which the hardness of the forming material differs in the direction of an axis, and the catheter body is in the field where the change object layer exists. The specific element which is an element different from the hardness of the material and affects the rigidity of the catheter body includes a specific region continuously changing with a predetermined direction in the axial direction, and In the specific region, it is formed so that there is no boundary that makes the hardness of the material different in the change target layer with respect to a portion having the lowest rigidity accompanying the specific element.
According to this configuration, since the catheter wall is formed using the change target layer, it is possible to cause a change in rigidity using a change in the hardness of the material. Further, in the region where the change target layer exists, a specific element that is different from the material hardness and affects the catheter rigidity continuously changes with a predetermined direction in the axial direction. Since the specific region is formed, there are a plurality of types of elements that change the rigidity, and it is possible to diversify the change mode of the rigidity. Therefore, it is possible to suitably set the rigidity balance.

  Furthermore, there is no boundary that makes the hardness of the material different in the change target layer with respect to a portion where the rigidity is lowest accompanying the specific element in the specific region. As a result, in the configuration in which the objects for changing the rigidity are diversified as described above, it is possible to prevent occurrence of a portion where the rigidity is locally reduced, thereby improving the kink resistance. It is possible to achieve the excellent effects as described above.

  The catheter of the second invention: a base layer that extends in the axial direction and is formed of the same material, and a change target layer that forms a catheter wall together with the base layer and has a different hardness in the forming material in the axial direction. The catheter body is an element different from the hardness of the material and affecting the rigidity of the catheter body in the region where the base layer and the change target layer exist. The specific element has a specific area continuously changing with a predetermined direction in the axial direction, and the change with respect to a portion where the rigidity is lowest accompanying the specific element in the specific area. The object layer is formed so that there is no boundary that makes the hardness of the material different.

  According to this configuration, the catheter wall portion is formed using the base layer and the change target layer, so that a tube joint as in the case where a plurality of tubes are connected in the axial direction is not generated. However, it is possible to cause a change in rigidity using a change in the hardness of the material. In addition, in the region where the base layer and the layer to be changed exist, specific elements that are different from the material hardness and affect the rigidity of the catheter continue in a predetermined direction in the axial direction. By forming the specific region that changes with time, there are a plurality of types of elements that change the rigidity, and it is possible to diversify the manner of changing the rigidity. Therefore, it is possible to suitably set the rigidity balance.

  Furthermore, there is no boundary that makes the hardness of the material different in the change target layer with respect to a portion where the rigidity is lowest accompanying the specific element in the specific region. As a result, in the configuration in which the objects for changing the rigidity are diversified as described above, it is possible to prevent occurrence of a portion where the rigidity is locally reduced, thereby improving the kink resistance. It is possible to achieve the excellent effects as described above.

  3rd invention catheter: In 1st or 2nd invention, the said catheter body is formed so that the boundary which makes the hardness of the said material different in the said change object layer exists in the middle position of the axial direction of the said specific area | region. It is characterized by being. Thereby, it is possible to achieve the excellent effects as described above while increasing the degree of freedom of the position where the hardness of the material is changed in the change target layer.

  Fourth aspect of the catheter: In any one of the first to third aspects of the invention, the catheter body may be the change target layer even at a location where the rigidity is highest accompanying the specific element in the specific region. The material is formed so that there is no boundary that makes the material different in hardness. This makes it possible to further improve kink resistance.

  5th invention catheter: In any one of 1st thru | or 4th invention, the said specific area | region is formed so that the rigidity accompanying the said specific element may become low toward a distal side, The said most The point where the rigidity is lowered is a distal end portion of the specific region. Since the specific region is formed so that the rigidity associated with the specific element decreases toward the distal side, the followability and the force transmission can be improved. In this case, since the catheter is advanced in the living body by pushing the proximal end portion toward the distal side, the kink is likely to occur at the stiffness change at the distal side. On the other hand, since the boundary which makes the hardness of a material different in a change object layer does not exist in the distal end part of a specific area | region, the improvement of kink resistance is achieved.

  The catheter of the sixth invention: In any one of the first to fifth inventions, the specific region includes, as the specific element, a wall thickness of the catheter wall, a cross-sectional area of the lumen of the catheter body, and the catheter It is a region where at least one element of the size of the outer edge of the body changes. When the specific element is an element as described above, a fold is generated on the inner peripheral surface or the outer peripheral surface of the catheter body. And if the rigidity of such a fold portion is low, kinks are likely to occur. On the other hand, since there is no boundary where the hardness of the material changes in the change target layer with respect to this fold, the kink resistance can be improved.

It is an expanded sectional view of the distal region of a catheter body. It is a schematic whole side view which shows the structure of a catheter. FIG. 6 is an enlarged cross-sectional view of a distal region of a catheter body in another catheter. FIG. 6 is an enlarged cross-sectional view of a distal region of a catheter body in another catheter. FIG. 6 is an enlarged cross-sectional view of a distal region of a catheter body in another catheter.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. First, a schematic configuration of the catheter 10 will be described with reference to FIG. FIG. 2 is a schematic overall side view showing the configuration of the catheter 10.

  As illustrated in FIG. 2, the catheter 10 includes a tubular catheter body 11 and a hub 12 attached to a proximal end portion (base end portion) of the catheter body 11.

  A guide wire G is inserted into the lumen 13 (see FIG. 1) of the catheter body 11 when the catheter 10 is inserted into a blood vessel or the like. The lumen 13 is used as a passage for a contrast medium, a chemical liquid, a cleaning liquid, and the like. The hub 12 functions as an insertion port for the guide wire G into the lumen 13, an injection port for a contrast medium, a chemical solution, a cleaning solution, and the like into the lumen 13, and also functions as a grip portion when operating the catheter 10. To do. The length of the catheter 10 is 1 m to 2 m.

  The catheter body 11 has a multi-layer structure in which a plurality of layers are laminated in a predetermined range from the distal end (tip) to the proximal side at least. Specifically, the catheter body 11 has a multi-layer structure over the entire axial direction.

  The structure of the catheter body 11 will be described with reference to FIG. FIG. 1 is an enlarged cross-sectional view of a distal region of the catheter body 11.

  As shown in FIG. 1, the catheter body 11 is sandwiched between an inner layer 14 that defines the entire inner peripheral surface of the catheter body 11, an outer layer 15 that defines the entire outer peripheral surface of the catheter body 11, and the inner layer 14 and the outer layer 15. And an intermediate layer 16 provided as described above.

  The inner layer 14 is a layer serving as a base when forming the intermediate layer 16 and the outer layer 15. The inner layer 14 is formed using a synthetic resin. As the synthetic resin, those listed as materials of the outer layer 15 described later can be used, and specifically, the synthetic resin is formed using a low friction material. Thus, by forming the inner layer 14 with a low-friction material, the guide wire G and the inner peripheral surface of the catheter main body 11 when the catheter 10 is introduced into a target position in the living body along the guide wire G that has been preceded. It is possible to reduce the sliding resistance between the two. In addition, when a therapeutic catheter different from the present catheter 10 is inserted into the present catheter 10, it is possible to reduce the sliding resistance between the therapeutic catheter and the inner peripheral surface of the catheter body 11. It becomes.

  Specifically, polytetrafluoroethylene is used as a material for forming the inner layer 14. However, the material forming the inner layer 14 is arbitrary as long as the sliding resistance with the guide wire G or the treatment catheter can be reduced as compared with the material forming the outer layer 15. For example, polytetrafluoro A fluorine-containing resin different from ethylene may be used. Examples of the fluorine-containing resin include polyvinylidene fluoride and perfluoroalkoxy resin. Moreover, other than a fluorine-containing resin, for example, polyamide, polyimide, high-density polyethylene, or the like may be used. Further, a plurality of materials listed above may be used in combination.

  The thickness dimension of the inner layer 14 is arbitrary, but is preferably smaller than the thickness dimension of the outer layer 15. Specifically, 0.005 mm to 0.030 mm is preferable. This makes it possible to reduce the diameter of the catheter main body 11 while favorably reducing the sliding resistance.

  The intermediate layer 16 has a role of reinforcing the catheter body 11. Specifically, stainless steel is used as a material for forming the intermediate layer 16. However, the material for forming the intermediate layer 16 is arbitrary as long as the above-described reinforcing effect is obtained. For example, a superelastic alloy such as a Ni—Ti alloy or a Ni—Ti—Co alloy may be used. Other metals such as nickel and titanium may be used. Further, the intermediate layer 16 is not limited to metal, and may be polyester such as polyethylene terephthalate or polyolefin such as polyethylene. Rigid polyvinyl chloride, polyamide, polyimide, polystyrene, polyurethane, polycarbonate, ABS resin, Other synthetic resins such as acrylic resin, methacrylic resin, polyacetal, fluorine-containing resin, and polyether ketone may be used. Carbon fiber or glass fiber may be used. Further, a plurality of types of materials listed above may be used in combination.

  Although the intermediate layer 16 may be formed by a plate-like wall portion, the catheter body 11 is formed by using a linear element formed of the material as described above. Specifically, the intermediate layer 16 is formed by knitting the linear elements into a mesh shape. However, it is not limited to a mesh shape, and may be a coil shape. Thus, by forming the intermediate layer 16 with linear elements, the flexibility of the bending can be enhanced while the catheter body 11 is reinforced.

  The linear element forming the intermediate layer 16 is formed so that its cross-sectional shape is rectangular, but is not limited thereto, and may be circular or elliptical. The linear element forming the intermediate layer 16 is formed so that the thickness dimension of the intermediate layer 16 is approximately the same as that of the inner layer 14. The thickness dimension is arbitrary, but is preferably smaller than the thickness dimension of the outer layer 15. Specifically, 0.01 mm to 0.05 mm is preferable.

  Moreover, it is preferable that the pitch between the linear elements adjacent to each other in the axial direction is constant. Although the dimension of the pitch is arbitrary, it is preferably 0.5 mm to 3.0 mm in order to enhance flexibility with respect to bending while reinforcing the catheter body 11 as described above.

  The outer layer 15 is provided so as to cover the inner layer 14 and the intermediate layer 16 from the outside. The outer layer 15 is formed using a synthetic resin. Examples of the synthetic resin include polyamide, polyamide elastomer, polyimide, polyimide elastomer, polypropylene, polyethylene, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polybutylene terephthalate, polyester elastomer, polyurethane, polyurethane elastomer, polyvinyl chloride, polystyrene. , Polystyrene elastomer, ethylene-tetrafluoroethylene copolymer, fluorine-based elastomer, silicon rubber, latex rubber and the like. Moreover, these may be used independently and the mixture which combined 2 or more types may be used.

  Here, the polyamide elastomer is, for example, nylon 6, nylon 64, nylon 66, nylon 610, nylon 612, nylon 46, nylon 9, nylon 11, nylon 12, N-alkoxymethyl modified nylon, hexamethylenediamine-isophthalic acid. A compound that generates a repeating unit of various aliphatic or aromatic polyamides such as a condensation polymer, a metaxyloxydiamine-adipic acid condensation polymer, and a compound that generates a repeating unit of another polymer such as polyester or polyether And a polymer obtained by softening the above-mentioned various aliphatic or aromatic polyamides with a plasticizer or the like, or a mixture thereof. The polyamide elastomer is preferably a block copolymer having the above-mentioned various aliphatic or aromatic polyamides as a hard segment and the other polymer as a soft segment.

  The polyester elastomer is a polymer of a compound that generates a repeating unit of a saturated polyester such as polyethylene terephthalate or polybutylene terephthalate and a compound that generates a repeating unit of another polymer such as polyether or polyester, It is a concept that includes a material softened with an agent or the like, or a mixture thereof. The polyester elastomer is preferably a block copolymer of the saturated polyester and the other polymer.

  In this catheter body 11, a mixture of polyamide and polyamide elastomer is used as the outer layer 15, and more specifically, a mixture of nylon and nylon elastomer (block copolymer) is used. Further, the outer layer 15 is not formed of the same material over the entire axial direction, but the hardness (that is, the longitudinal elastic modulus) of the outer layer 15 is stepwise from the proximal end portion toward the distal end portion. The forming materials are different so as to be smaller.

  That is, as the outer layer 15, as shown in FIG. 2, from the distal end portion toward the proximal end portion, the first outer layer region 21, the second outer layer region 22, the third outer layer region 23, and the fourth outer layer. A region 24, a fifth outer layer region 25, and a sixth outer layer region 26 are provided. Each of the outer layer regions 21 to 26 is formed so that the hardness gradually decreases from the sixth outer layer region 26 toward the first outer layer region 21.

  As the hardness of each of the outer layer regions 21 to 26, the Shore hardness of the first outer layer region 21 is preferably 35D to 55D, the Shore hardness of the second outer layer region 22 is 40D to 65D, and the Shore hardness of the third outer layer region 23 is Is 50D to 70D, the Shore hardness of the fourth outer layer region 24 is 55D to 80D, the Shore hardness of the fifth outer layer region 25 is 55D to 80D, and the Shore hardness of the sixth outer layer region 26 is 55D to 80D. is there.

  The change in the hardness of each of the outer layer regions 21 to 26 is realized by changing either the type of nylon, the type of nylon elastomer, the mixing ratio of nylon and nylon elastomer, or a combination thereof. Specifically, a change in hardness is realized by changing at least one of the type of nylon and the type of nylon elastomer without changing the mixing ratio of nylon and nylon elastomer between adjacent predetermined outer layer regions. The hardness change is realized by changing the mixing ratio of nylon and nylon elastomer without changing the type of nylon and the type of nylon elastomer between other adjacent outer layer regions. Between adjacent outer layer regions, at least one of the type of nylon and the type of nylon elastomer is changed, and the change in hardness is realized by changing the mixing ratio of nylon and nylon elastomer. Thus, by causing the hardness change, the hardness of the outer layer regions 21 to 26 can be easily set finely.

  However, it is not limited to the said structure, In all the outer layer area | regions 21-26, as a structure by which the hardness change is implement | achieved by changing the mixing ratio of the same kind nylon and the same kind nylon elastomer in steps. Also good. That is, from the sixth outer layer region 26 to the first outer layer region 21, the mixing ratio of nylon is gradually reduced with respect to the total weight of nylon and nylon elastomer, while the mixing ratio of nylon elastomer is stepwise. It is possible to realize the above-described change in hardness by preparing the forming material for each of the outer layer regions 21 to 26 so as to increase.

  Preferably, the first outer layer region 21 is made of a material in which nylon and nylon elastomer are mixed in a ratio of 0 to 20 to 80 to 100, and the second outer layer region 22 is made of nylon and nylon elastomer of 10 to 30. The third outer layer region 23 is formed of a material in which nylon and nylon elastomer are mixed in a ratio of 15 to 35 to 65 to 85, and the third outer layer region 23 is formed of a material mixed in a ratio of 70 to 90. The fourth outer layer region 24 is formed of a material in which nylon and nylon elastomer are mixed at a ratio of 40-60 to 40-60, and the fifth outer layer region 25 is 40-60: 40-60 of nylon and nylon elastomer. The sixth outer layer region 26 is made of 40-60 to 40-60 nylon and nylon elastomer. It is formed by mixing materials in a total.

  Further, for example, in all the outer layer regions 21 to 26, although the mixing ratio of nylon and nylon elastomer is the same, it is possible to cause a change in hardness by making at least one of nylon and nylon elastomer different. Good. Further, the hardness may be changed by using a different resin-based forming material.

  Each of the outer layer regions 21 to 26 is formed so that the length dimension in the axial direction decreases stepwise from the sixth outer layer region 26 toward the first outer layer region 21. However, the present invention is not limited to this, and in each of the outer layer regions 21 to 26, some regions that are continuous in the axial direction may have the same or substantially the same length in the axial direction. The length dimensions in the axial direction of the 26 may be the same or substantially the same, and some of the outer layer regions 21 to 26 are more axial than the region existing on the proximal side. It is good also as a structure with a large length dimension. The length of each outer layer region 21 to 26 in the axial direction is preferably 30 mm to 100 mm. Although the thickness dimension of each outer layer area | region 21-26 is arbitrary, when reducing the load to the structure | tissue in the living body, such as a blood vessel, it is preferable that it is larger than the thickness dimension of the inner layer 14 or the intermediate | middle layer 16. FIG.

  In addition, on the surface of the outer layer 15, a cellulose polymer such as hydroxypropyl cellulose, a polyethylene oxide polymer such as polyethylene glycol, a maleic anhydride polymer such as methyl vinyl ether maleic anhydride copolymer, an acrylamide polymer such as polyacrylamide, water-soluble nylon, etc. May be used to apply a hydrophilic coating. Moreover, you may attach the radiopaque marker formed using metals, such as gold | metal | money, platinum, tungsten, various alloys, etc. in a predetermined position.

  Next, the configuration of the distal region (region of a predetermined range from the distal end portion toward the proximal side) of the catheter body 11 will be described with reference to FIG.

  The structure of the distal region of the catheter body 11 is set so that the rigidity is reduced and narrowed toward the distal end. Specifically, the outer tapered regions 31 and 32 that continuously decrease the outer diameter toward the distal side while keeping the inner diameter of the catheter body 11 constant, and the inner diameter and the outer diameter while keeping the wall thickness of the catheter body 11 constant. And an inner and outer tapered region 33 that continuously lowers both of them toward the distal side. Two outer tapered regions 31 and 32 are provided, and these outer tapered regions 31 and 32 are formed so as to sandwich the inner and outer tapered regions 33 in the axial direction. Further, each of the outer tapered regions 31 and 32 is sandwiched in the axial direction by the constant regions 34, 35, 36, and 37 in which the thickness, the inner diameter, and the outer diameter are constant.

  The rate of change of the outer diameter of the outer tapered regions 31 and 32 (the outer diameter of the distal end relative to the outer diameter of the proximal end of the region) is arbitrary as long as the passability and kink resistance can be improved. However, 1% to 10% is preferable. Further, the rate of change of the outer diameter of the inner and outer tapered regions 33 (the outer diameter of the distal end relative to the outer diameter of the proximal end of the region) is arbitrary as long as the passability and kink resistance can be improved. However, 10% to 40% is preferable. Further, the rate of change of the inner diameter of the inner and outer tapered regions 33 (the inner diameter of the distal end portion with respect to the inner diameter of the proximal end portion of the region) is arbitrary as long as the passability and kink resistance can be improved. 1% to 40% is preferable.

  In each taper area | region 31-33, the pitch of the linear element which forms the intermediate | middle layer 16 is set constant. In addition, the pitch of the linear elements is the same as the pitch of the linear elements in the fixed regions 34 to 37. Thereby, also in each taper area | region 31-33, it becomes possible to reinforce by the intermediate | middle layer 16 similarly to the stabilization area | regions 34-37.

  In the configuration in which the tapered regions 31 to 33 are formed as described above, different outer layer regions exist on the proximal side and the distal side for each of the tapered regions 31 to 33. That is, the proximal outer tapered region 32 is included in the third outer layer region 23, and at least the fourth outer layer region 24 exists on the proximal side of the outer tapered region 32, and the distal side At least the third outer layer region 23 exists. The outer taper region 31 on the distal side is included in the first outer layer region 21, and at least the second outer layer region 22 exists on the proximal side of the outer taper region 31, and the distal side The first outer layer region 21 is present in. The inner / outer taper region 33 exists from the second outer layer region 22 to the third outer layer region 23, and at least the third outer layer region 23 exists on the proximal side of the inner / outer taper region 33. At least the second outer layer region 22 exists on the distal side.

  In each tapered region 31 to 33, the outer layer 15 is formed at a portion where the rigidity is lowest due to the structure of the region so that there is no boundary between the plurality of outer layer regions. Specifically, for each of the tapered regions 31 to 33, there is a boundary between the outer layer regions closer to the proximal side than the distal ends of the tapered regions 31 to 33.

  More specifically, although the proximal end portion of the proximal outer tapered region 32 exists at the boundary between the third outer layer region 23 and the fourth outer layer region 24, the proximal tapered region 32 depends on the outer tapered region 32. The distal end portion, which is the portion having the lowest rigidity due to the taper shape, exists at an intermediate position in the axial direction of the third outer layer region 23.

  The distal outer tapered region 31 has a proximal end portion at the boundary between the first outer layer region 21 and the second outer layer region 22, but due to the tapered shape of the outer tapered region 31. A distal end portion where the rigidity is lowest is present at an intermediate position in the axial direction of the first outer layer region 21.

  The proximal end of the inner and outer tapered region 33 is present at an intermediate position in the axial direction of the third outer layer region 23, and the distal end thereof is disposed at an intermediate position in the axial direction of the second outer layer region 22. Existing. In addition, a boundary between the second outer layer region 22 and the third outer layer region 23 exists at an intermediate position in the axial direction of the inner and outer tapered regions 33.

  In the configuration in which the tapered regions 31 to 33 are formed as described above, a crease is generated at a tapered point where the rigidity is lowest due to the tapered shape. If there is a boundary between the outer layer regions in the fold portion, there is a concern that kinks may occur. On the other hand, the occurrence of the kink is suppressed by preventing the boundary between the outer layer regions from overlapping the portion where the fold occurs. Therefore, in the configuration in which the passability, followability, transferability and kink resistance required for the catheter 10 are improved by changing the hardness of the forming material, setting the outer diameter, and setting the inner diameter, the kink resistance is further improved. Can be achieved.

  Next, a method for manufacturing the catheter 10 will be briefly described.

  First, the inner layer 14 is extrusion-molded with respect to a mold molded in accordance with the shape of the lumen 13 of the catheter 10. Next, a linear element is wound around the outer peripheral surface of the inner layer 14. In this winding, the linear element is wound at a constant pitch by a commercially available device for winding. Thereby, the intermediate layer 16 is formed on the surface of the inner layer 14. Next, the outer layer regions 21 to 26 are extrusion coated on the inner layer 14 on which the intermediate layer 16 is formed. At this time, the thickness of each outer layer region 21 to 26 is adjusted. Next, the tapered regions 31 to 33 are formed through polishing, heating, or the like. Then, the manufacture of the catheter 10 is completed by applying a hydrophilic coating, attaching an X-ray opaque marker, and attaching the hub 12.

  Next, a method for using the catheter 10 will be briefly described.

  First, a guiding catheter is inserted through a sheath introducer inserted into a blood vessel. Next, the guide wire G is inserted into the lumen 13 of the catheter 10 and the guiding catheter, and inserted to a position beyond the treatment target site or the inspection target site. Subsequently, the catheter 10 is inserted along the guide wire G to a treatment target site or a test target site while performing a push-pull or twist operation. When the distal end of the catheter body 11 reaches a treatment target site or a test target site, a medical solution or a contrast medium is injected to perform treatment or inspection.

  The catheter 10 is mainly passed through a blood vessel as described above, and is used for treating or examining the inside of the blood vessel. However, in the living body such as a ureter other than the blood vessel or a digestive tract, It can also be applied to “body cavity”.

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

  The wall portion of the catheter body 11 has an inner layer 14 and an intermediate layer 16 as a base layer extending in the axial direction and formed of the same material, and an outer layer as a change target layer having different hardness in the forming material in the axial direction. 15 has a multi-layer structure. Accordingly, it is possible to cause a change in rigidity using a change in the hardness of the material without causing a joint of the tubes as in the case where a plurality of tubes are connected in the axial direction.

  In the region where the inner layer 14, the intermediate layer 16 and the outer layer 15 are present, the catheter body is a specific element which is an element different from the hardness of the material and which affects the rigidity of the catheter body 11. An inner and outer tapered region 33 (corresponding to a specific region) is formed in which the inner diameter of 11 (the cross-sectional area of the lumen 13) and the outer diameter (size of the outer edge) decrease toward the distal side. As a result, there are a plurality of types of elements that change the rigidity, including the hardness of the material, and it is possible to diversify the change modes of the rigidity. Therefore, it is possible to suitably set the rigidity balance.

  Furthermore, there is no boundary in the outer layer 15 that makes the hardness of the material different from the distal end portion, which is the portion having the lowest rigidity accompanying the specific element in the inner and outer tapered regions 33. As a result, in the configuration in which the objects for changing the rigidity are diversified as described above, it is possible to prevent occurrence of a portion where the rigidity is locally reduced, thereby improving the kink resistance. It is possible to achieve the excellent effects as described above.

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

  (1) In the modification shown in FIG. 3, the relationship between the inner and outer tapered regions 33 and the outer layer regions 21 to 26 is the same as that of the above embodiment. On the other hand, the entire outer tapered region 32 on the proximal side is present in the middle of the third outer layer region 23 in the axial direction, and the outer tapered region 31 on the distal side is entirely composed of the first outer layer region 21. It exists in the middle of the axial direction. Thereby, about all of each taper area | regions 31-33, neither of the both ends of a proximal side and a distal side has overlapped with the boundary between outer-layer area | regions.

  In the modification shown in FIG. 4, the relationship between the inner and outer tapered regions 33 and the outer layer regions 21 to 26 is the same as that in the above embodiment. On the other hand, the proximal outer taper region 32 has a proximal end located in the middle of the fourth outer layer region 24 in the axial direction, and a distal end of the third outer layer region 23. The distal outer taper region 31 is located in the middle of the axial direction, and the proximal end of the distal outer tapered region 31 is located in the middle of the second outer layer region 22 in the axial direction. The part exists in the middle of the axial direction of the first outer layer region 21. Thereby, about all of each taper area | regions 31-33, neither of the both ends of a proximal side and a distal side has overlapped with the boundary between outer-layer area | regions.

  According to the configuration of each of the above-described modified examples, since the overlap with the boundary between the outer layer regions is avoided at all the places where the folds are generated, the kink resistance is improved.

  (2) In the modified catheter 40 shown in FIG. 5, unlike the catheter 10, the catheter body 41 has a two-layer structure of an inner layer 42 and an outer layer 43. However, as in the case of the catheter 10, an intermediate layer 16 may be interposed. The material for forming the inner layer 42 is the same as that for the inner layer 14 of the catheter 10. Further, the material for forming the outer layer 43 is the same as that of the outer layer 15 of the catheter 10, and a plurality of outer layer regions 43a, 43b, 43c, 43d, and 43e are provided so that the hardness gradually decreases toward the distal side. ing.

  In this case, the catheter 40 is not provided with the outer tapered regions 31 and 32 and the inner and outer tapered regions 33 as in the catheter 10, and instead, the catheter 40 is continuously continuous toward the distal side while keeping the outer diameter constant. In particular, an inner tapered region 44 having a larger inner diameter and a reverse tapered region 45 in which both the inner diameter and the outer diameter increase toward the distal side with a constant thickness are provided. By providing the inner tapered region 44 and the reverse tapered region 45, the cross-sectional area of the lumen 41a can be expanded toward the distal side. Thereby, for example, by using the catheter 40 as a suction catheter, it becomes easier to suck a thrombus.

  In the configuration in which the tapered regions 44 and 45 are formed as described above, the inner tapered region 44 is formed across the second outer layer region 43b and the third outer layer region 43c. The distal end, where the stiffness is lowest due to the structure, does not overlap the boundary between the outer layer regions. The proximal end also does not overlap with the boundary between the outer layer regions. Incidentally, the boundary between the second outer layer region 43 b and the third outer layer region 43 c exists at an intermediate position in the axial direction of the inner tapered region 44.

  Moreover, the reverse taper area | region 45 is formed over the 1st outer layer area | region 43a and the 2nd outer layer area | region 43b, and the edge part of the proximal side of the reverse taper area | region 45 does not overlap with the boundary between outer layer area | regions. . Incidentally, the boundary between the first outer layer region 43a and the second outer layer region 43b exists in the middle of the reverse taper region 45 in the axial direction.

  As described above, according to the present catheter 40, even if the inner taper region 44 and the reverse taper region 45 exist, the portion having the lowest rigidity due to the taper shape and the portion causing the crease. The boundary between the outer areas does not overlap. Thus, in the configuration in which the outer layer regions 43a to 43e are provided to improve the followability and the transmission property while providing the tapered regions 44 and 45 to facilitate the thrombus suction, the kink resistance is improved. Figured.

  (3) In the catheter 10, the intermediate layer 16 may be omitted. Further, in the configuration in which the intermediate layer 16 is not provided or in the configuration having the intermediate layer 16 as in the catheter 10, the outer layer 15 is formed of the same material over the entire axial direction, while the inner layer 14 is formed. It is good also as a structure which changes the hardness of a forming material in an axial direction. Further, in the three-layer structure like the catheter 10, the hardness of the forming material of the intermediate layer 16 may be changed in the axial direction. Further, in the region where the hardness of the forming material changes, the base layer such as the inner layer 14 and the intermediate layer 16 may not be provided, but only the change target layer such as the outer layer 15 may be provided.

  (4) The region where the catheter wall is formed of the base layer such as the inner layer 14 and the intermediate layer 16 and the change target layer such as the outer layer 15 is limited to a configuration in which the entire region in the axial direction of the catheter body 11 exists. In other words, the region may exist only in a part of the catheter body 11 in the axial direction. For example, it is good also as a structure which the said area | region exists only in the predetermined range toward the proximal side from the distal end part of the catheter main body 11. FIG. Even in this case, by forming specific regions such as the outer tapered regions 31 and 32 and the inner and outer tapered regions 33 in the region, it becomes possible to suitably set the rigidity balance, and in the specific region By preventing the boundary where the hardness of the material is different from being present at the portion where the rigidity is lowest, the kink resistance can be improved.

  (5) A constant region 34 that is continuous on the distal side with respect to the outer tapered region 31, a constant region 35 that is continuous on the distal side with respect to the inner and outer tapered regions 33, and a far side with respect to the outer tapered region 32. At least one of the constant regions 36 continuous on the distal side is such that at least one element of the wall thickness of the catheter wall, the cross-sectional area of the lumen 13, and the size of the outer edge of the catheter body 11 is directed toward the distal side. It is good also as a structure which becomes small continuously. As the element that fluctuates in the fixed region, a configuration that is the same type as the element that fluctuates in a region continuous on the proximal side of the fixed region can be considered. However, the constant region has a configuration in which the rate of change per unit length of the element is different from the rate of change of a region continuous on the proximal side with respect to the constant region. Even in this case, it is preferable that there is no boundary where the hardness of the forming material changes at the boundary between the stabilization region and the region continuous on the proximal side. In particular, in a configuration in which the rate of change is smaller in the fixed region than in a region continuous on the proximal side, there are folds that are likely to cause kinks, so It is preferable that there is no boundary where the hardness of the forming material changes at the boundary with the continuous region on the distal side.

  (6) Specific elements that are different from the material hardness and affect the rigidity of the catheter body include the wall thickness of the catheter wall, the cross-sectional area of the lumen of the catheter body, and the outer edge of the catheter body In addition to the size of, for example, the suction port in the suction catheter in which the suction port is formed on the side wall of the catheter body, or the RX type in which the proximal end opening of the guide wire lumen is formed at an intermediate position in the axial direction of the catheter body And the proximal end opening of the catheter. In this case, it is preferable to generate a boundary where the hardness of the forming material changes at a position shifted in the axial direction with respect to the region where the suction port and the proximal end opening are present.

  (7) The present invention may be applied to a balloon catheter. For example, the present invention may be applied to a catheter body that generates a guide wire lumen in a balloon catheter, and to a catheter body that generates a fluid lumen through which a compressed fluid passes when the balloon is inflated or deflated. The present invention may be applied. The balloon catheter may be any of PTCA, PTA, IABP, and the like. Further, the present invention may be applied to various suction catheters, blood flow blocking catheters, catheters for penetrating the distal end portion by pressing the distal end portion against a blockage site caused by a thrombus or the like.

  DESCRIPTION OF SYMBOLS 10 ... Catheter, 11 ... Catheter main body, 14 ... Inner layer which comprises base layer, 15 ... Outer layer which comprises change object layer, 16 ... Intermediate | middle layer which comprises base layer, 33 ... Inner / outer taper area | region as a specific area, 40 ... Catheter, 41 ... catheter body, 42 ... inner layer as base layer, 43 ... outer layer as change target layer, 44 ... inner tapered region as specific region, 45 ... reverse tapered region as specific region.

Claims (5)

A catheter body that forms a catheter wall and has a layer to be changed in which the hardness of the forming material varies stepwise in the axial direction;
The catheter body is
In the region where the change target layer exists, a specific element which is an element different from the hardness of the material and affects the rigidity of the catheter body is continuously provided with a predetermined direction in the axial direction. Specific areas that change over time,
And it is formed so that the boundary which makes the hardness of the material different in the change target layer does not exist with respect to the portion where the rigidity is lowest accompanying the specific element in the specific region ,
The said boundary exists in the middle position of the axial direction of the said specific area | region, The catheter characterized by the above-mentioned. A catheter body having a base layer that extends in the axial direction and is formed of the same material, and a change target layer that forms a catheter wall together with the base layer, and in which the hardness of the forming material varies stepwise in the axial direction. Prepared,
The catheter body is
In the region where the base layer and the change target layer exist, a specific element that is an element different from the hardness of the material and affects the rigidity of the catheter body has a predetermined directionality in the axial direction. It has a specific area that changes continuously with
And it is formed so that the boundary which makes the hardness of the material different in the change target layer does not exist with respect to the portion where the rigidity is lowest accompanying the specific element in the specific region ,
The said boundary exists in the middle position of the axial direction of the said specific area | region, The catheter characterized by the above-mentioned. The catheter body is formed so that there is no boundary that makes the hardness of the material different in the change target layer even at a portion where the rigidity is highest accompanying the specific element in the specific region. The catheter according to claim 1 or 2 , wherein the catheter is characterized. The specific region is formed such that rigidity associated with the specific element decreases toward the distal side,
The catheter according to any one of claims 1 to 3 , wherein the portion having the lowest rigidity is a distal end portion of the specific region. The specific region is a region in which at least one of the thickness of the catheter wall, the cross-sectional area of the lumen of the catheter body, and the size of the outer edge of the catheter body changes as the specific element. The catheter according to any one of claims 1 to 4 .

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