Catheter

Abstract

This invention provides a catheter having a novel structure and capable of achieving insertion of a blood vessel, etc., farther to a peripheral side through adjustment of deformation rigidity.　A catheter 10 includes a lumen 16 extending in a length direction. On a peripheral wall of the lumen 16, a hard first reinforcement material 26 extending in a spiral shape is provided in an embedded state. The first reinforcement material 26 includes: a plate coil-form reinforcement material 28 with a flat plate-form cross section arranged on a proximal end side in the length direction; and a linear coil-form reinforcement material 30 with a circular cross section arranged farther to a distal end side than the plate coil-form reinforcement material 28.

Description

catheter

[0001] The present invention relates to a catheter used, for example, for administering a medicinal solution or for suctioning a thrombus.

[0002] Catheters that are percutaneously inserted into blood vessels and used to aspirate and remove thrombi, administer medicinal solutions, etc. As disclosed in International Publication No. 2019 / 004100 (Patent Document 1), for example, the catheter has a lumen extending in the longitudinal direction, and it is possible to administer medicinal solutions into blood vessels, aspirate thrombi, insert a therapeutic instrument, etc. through the lumen.

[0003] The catheter of Patent Document 1 is provided with a reinforcing structure that reinforces the peripheral wall of the lumen in order to achieve the properties required for reaching the treatment site from the arm, leg, etc., such as pushability, torque performance, flexible bending, recovery, and kink resistance. The reinforcing structure of Patent Document 1 is composed of a coil-shaped first reinforcing member and a braid-shaped second reinforcing member.

[0004] International Publication No. 2019 / 004100

[0005] However, catheters inserted into thinner blood vessels, such as those deep in the brain, must have a small outer diameter. On the other hand, the lumen diameter must be large to allow for effective administration of medication, insertion of therapeutic instruments, and suction of thrombi. Therefore, the smaller the diameter of a catheter, the thinner the circumferential wall of the lumen tends to be.

[0006] However, in the reinforcing member made of metal wire or synthetic resin fiber as described in Patent Document 1, the thickness of the wire or fiber is generally constant regardless of the outer diameter of the catheter. Therefore, for example, in catheters with relatively small diameters or catheter tip portions that tend to have small diameters due to axial taper, the reinforcing member content (area percentage) in the cross section of the peripheral wall tends to be high. In particular, the distal end of a catheter inserted closer to the periphery of a blood vessel tends to have a smaller diameter than the proximal end, and therefore tends to have a higher reinforcing member content. Furthermore, if the reinforcing member content in the peripheral wall becomes high, there is a risk that the reinforcing member may break through the peripheral wall of the lumen and become exposed.

[0007] Furthermore, because small-diameter catheters are inserted into narrow blood vessels with more complex bends, they are required to have different characteristics than relatively large-diameter catheters. Specifically, the distal end portion, which is inserted into narrow blood vessels, must have a high degree of flexibility to follow the complex bends of the blood vessel, while the proximal end portion must have a high degree of pushability, etc., to efficiently transmit the operating force applied to the proximal end of the catheter to the distal end portion. While providing a reinforcing member only to the proximal end is one way to satisfy these different requirements for the distal and proximal end portions, this would result in a large difference in hardness between the proximal end portion with the reinforcing member and the distal end portion without the reinforcing member, which would increase the risk of the catheter breaking due to stress concentration, etc.

[0008] An object of the present invention is to provide a catheter of a novel structure which is designed to improve operability when inserting it into a body lumen such as a more distal narrow blood vessel.

[0009] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0010] The first aspect is a catheter having a lumen extending in the longitudinal direction, in which a first rigid reinforcing material extending in a spiral shape is embedded in the peripheral wall of the lumen, and the first reinforcing material includes a plate coil reinforcing material with a flat cross section arranged on the proximal end side in the longitudinal direction, and a wire coil reinforcing material with a circular cross section arranged on the distal end side of the plate coil reinforcing material.

[0011] In a catheter constructed according to this aspect, the cross-sectional shape of the hard first reinforcing member reinforcing the peripheral wall of the lumen differs between the proximal end and the distal end in the catheter's longitudinal direction, with the proximal end being a plate coil-shaped reinforcing member with a flat cross section that tends to increase deformation rigidity in the catheter's longitudinal direction and in the crushing direction (radial direction), while the distal end being a wire coil-shaped reinforcing member with a circular cross section that tends to decrease deformation rigidity in the catheter's curvature direction, etc. This improves the efficiency of transmission of insertion force when pushing the catheter toward the distal end at the proximal end, and stabilizes the lumen shape. Meanwhile, the distal end at which the wire coil-shaped reinforcing member is arranged achieves effective transmission of the insertion force (pushability) while also achieving excellent followability to the curvature of the blood vessel. In this way, by achieving the high performance required for the tip and base portions of different catheters by using different cross-sectional shapes of the first reinforcing member, it becomes possible to improve operability during procedures such as inserting the tip portion of the catheter into more distal, complexly curved, thin blood vessels.

[0012] In a second aspect, in the catheter described in the first aspect, the wire coil reinforcing member has a structure in which a flat bundle of wires, which is made up of multiple wires arranged flat in the longitudinal direction of the catheter, extends in a spiral shape.

[0013] In a catheter constructed according to this aspect, by forming the wire coil reinforcing member from a wire rod with a small outer diameter, it is possible to reduce the outer diameter of the catheter while efficiently ensuring the effect of the wire coil reinforcing member in reinforcing the circumferential wall of the lumen, for example, the effect of preventing the catheter from kinking due to localized crushing. Furthermore, by changing the number of wire rods constituting the flat-bundle wire, it is possible to adjust the strength of the reinforcing effect of the wire coil reinforcing member while preventing the catheter from becoming too large in diameter.

[0014] In a third aspect, in the catheter described in the first or second aspect, the plate coil-shaped reinforcing material and the wire coil-shaped reinforcing material are continuously arranged in a butt-to-butt relationship along the length of the catheter without overlapping each other.

[0015] A catheter constructed according to this embodiment can prevent the stiffness of the catheter from being locally increased due to radial overlap between the plate coil reinforcing member and the wire coil reinforcing member, and can also prevent the catheter from being locally increased in diameter due to overlap between the plate coil reinforcing member and the wire coil reinforcing member.

[0016] In a fourth aspect, in the catheter according to any one of the first to third aspects, the plate coil-shaped reinforcing material and the wire coil-shaped reinforcing material are both made of metal.

[0017] A catheter constructed according to this embodiment allows the coil-shaped reinforcing member and the wire coil-shaped reinforcing member to have substantially the same basic material properties, and achieves the effective reinforcing effect of the plate coil-shaped reinforcing member and the wire coil-shaped reinforcing member in a compact, lightweight device. Furthermore, spiral plate coil-shaped reinforcing member and wire coil-shaped reinforcing member can be easily manufactured.

[0018] In a fifth aspect, in the catheter according to any one of the first to fourth aspects, a soft second reinforcing material extending in a crosswise manner is embedded in the peripheral wall of the lumen, and the second reinforcing material has a structure in which a plurality of flat bundle cords, each of which is made of a plurality of fibers arranged flat, are arranged in a crosswise manner, and the number of fibers in the flat bundle cords constituting the second reinforcing material varies along the length of the catheter.

[0019] With a catheter constructed in accordance with this aspect, for example, the reinforcing action of the second reinforcing material more effectively improves the transmission efficiency of the insertion force when pushing the catheter toward the distal end and the shape stability of the surrounding wall of the lumen.

[0020] By varying the number of fibers in the flat bundle cord that constitutes the second reinforcing material along the length of the catheter, the reinforcing effect of the second reinforcing material can be changed relatively smoothly along the length of the catheter. Furthermore, because the flat bundle cord is formed by arranging multiple fibers flatly, it is possible to prevent changes in the outer diameter of the catheter due to an increase or decrease in the number of fibers.

[0021] In a sixth aspect, the catheter is any one of the first to fifth aspects, and includes a tubular inner layer that provides the inner surface of the lumen, and a tubular outer layer that covers the inner layer and the first reinforcing material from the outer periphery. The plate coil-shaped reinforcing material and the wire coil-shaped reinforcing material that constitute the first reinforcing material are arranged continuously in the length direction of the catheter, so that the first reinforcing material has a cross-sectionally changing portion, and the tip side of the plate coil-shaped reinforcing material located on the proximal end side of the cross-sectionally changing portion is adhered to the surface of the inner layer.

[0022] In a catheter constructed according to this embodiment, the distal end of the plate coil reinforcing member located on the proximal end side is bonded to the surface of the inner layer, thereby suppressing deformation of the plate coil reinforcing member at the distal end side. Therefore, even if there is a large difference in deformation rigidity between the plate coil reinforcing member and the wire coil reinforcing member or if the distal end of the plate coil reinforcing member is a free end, the plate coil reinforcing member can be prevented from climbing onto the outer periphery of the wire coil reinforcing member at the cross-sectionally changing portion when a pushing force (insertion force) is applied to the catheter from the proximal end side to the distal end side.

[0023] In particular, in small-diameter catheters inserted to more distal lesions, the catheter and first reinforcing member are long, and when inserted into, for example, peripheral blood vessels with complex shapes, torsional forces and the like are exerted in addition to insertion forces. Therefore, in small-diameter catheters, the plate coil-shaped reinforcing member is more likely to ride up on the wire coil-shaped reinforcing member, but by adopting the structure according to this embodiment, it is possible to effectively prevent the plate coil-shaped reinforcing member from riding up on the wire coil-shaped reinforcing member. Note that in the catheter according to this embodiment, instead of or in addition to the distal end of the plate coil-shaped reinforcing member being bonded to the surface of the inner layer, it is also possible to wrap the distal end of the plate coil-shaped reinforcing member in the circumferential direction and fix adjacent portions in the longitudinal direction to each other at several circumferential locations (one or more locations) by welding or the like.

[0024] A seventh aspect is a catheter having a lumen extending in the longitudinal direction, in which a soft second reinforcing material extending in a crosswise manner is embedded in the peripheral wall of the lumen, and the second reinforcing material is structured so that a plurality of flat bundle cords, each made of a plurality of fibers arranged flat, are arranged in a crosswise manner, and the number of fibers in the flat bundle cords constituting the second reinforcing material varies along the length of the catheter.

[0025] With a catheter constructed in accordance with this aspect, for example, the reinforcing action of the second reinforcing material more effectively improves the transmission efficiency of the insertion force when pushing the catheter toward the distal end and the shape stability of the surrounding wall of the lumen.

[0026] By varying the number of fibers in the flat bundle cord that constitutes the second reinforcing material along the length of the catheter, the reinforcing effect of the second reinforcing material can be varied along the length of the catheter. Furthermore, because the flat bundle cord is formed by arranging multiple fibers flat, it is possible to prevent changes in the outer diameter of the catheter due to an increase or decrease in the number of fibers.

[0027] In an eighth aspect, in the catheter according to the seventh aspect, the flat bundle cords are arranged crosswise and braided together to form the second reinforcing member with a braided structure.

[0028] In a catheter constructed in accordance with this embodiment, the second reinforcing material has a braided structure, which allows the reinforcing effect of the second reinforcing material on the peripheral wall of the lumen to be obtained more effectively than in a spiral structure, etc.

[0029] In a ninth aspect, in the catheter described in the seventh or eighth aspect, the number of fibers in the flat bundle cord constituting the second reinforcing material is smaller at the distal end side than at the proximal end side in the catheter length direction.

[0030] With a catheter constructed according to this aspect, at the proximal end of the catheter where the flat bundle cord has a large number of fibers, the high reinforcing effect of the second reinforcing material improves the transmission efficiency of the operating force applied to the catheter and stabilizes the lumen shape, etc. At the distal end of the catheter where the flat bundle cord has a small number of fibers, the reinforcing effect of the second reinforcing material effectively realizes the transmission of the operating force while also achieving excellent followability to the curvature of a blood vessel, for example.

[0031] In a tenth aspect, in the catheter according to any one of the seventh to ninth aspects, the fibers of the flat bundle cords constituting the second reinforcing material are not continuous with each other in regions in the length direction of the catheter where the number of fibers of the flat bundle cords is different.

[0032] According to a catheter constructed in accordance with this aspect, it is possible to easily set the difference in the number of fibers in the flat bundle cord along the length of the catheter.

[0033] In an eleventh aspect, in the catheter described in the tenth aspect, at the boundary between regions in the length direction of the catheter where the number of fibers in the flat bundle cord constituting the second reinforcing material is different, the ends of the fibers constituting the flat bundle cord in both regions overlap each other.

[0034] In a catheter constructed according to this aspect, if the discontinuous separate fibers are spaced apart in the longitudinal direction of the catheter, there will be areas between the separate fibers where the reinforcing effect of the second reinforcing material is not exerted, and these areas are likely to cause problems such as kinking. Therefore, by overlapping the ends of the separate fibers at the boundaries of areas where the number of fibers in the flat bundle cord is different, it is possible to prevent the formation of areas without the second reinforcing material.

[0035] A twelfth aspect is a catheter having a lumen extending in the longitudinal direction, in which a soft second reinforcing material extending in a crosswise manner is embedded in the peripheral wall of the lumen, and the second reinforcing material is structured so that a plurality of flat bundle cords, each of which is made of a plurality of fibers arranged flat, are arranged in a crosswise manner, and the content of the fibers constituting the flat bundle cords on the cross section of the catheter is set to be smaller at the distal end side than at the proximal end side in the longitudinal direction of the catheter, and a transition region is provided in the middle part in the longitudinal direction where the content of the fibers is set between the proximal end side and the proximal end side.

[0036] In a catheter constructed according to this aspect, the difference in fiber content across the catheter cross section causes the reinforcing effect of the second reinforcing material to be stronger at the proximal end than at the distal end. Therefore, at the proximal end, where the fiber content is higher, the high reinforcing effect of the second reinforcing material improves the efficiency of transmission of operating force and stabilizes the lumen shape. At the distal end, where the fiber content is lower, the reinforcing effect of the second reinforcing material effectively transmits operating force while also achieving excellent conformability to, for example, the curvature of a blood vessel.

[0037] By providing a transition region in the middle portion of the catheter in the longitudinal direction, a sudden change in the reinforcing effect of the second reinforcing material along the length of the catheter is prevented, thereby, for example, reducing stress concentration in the area where the reinforcing effect changes.

[0038] A thirteenth aspect is a catheter having a lumen extending in the longitudinal direction, comprising a tubular inner layer that provides the inner circumferential surface of the lumen, a hard first reinforcing material that extends spirally along the surface of the inner layer, and a tubular outer layer that covers the inner layer and the first reinforcing material from the outer periphery, wherein the first reinforcing material has a cross-sectionally varying portion having a different cross-sectional shape on the proximal end side and the distal end side in the longitudinal direction of the catheter, and the tip side of the first reinforcing material located on the proximal end side of the cross-sectionally varying portion is adhered to the surface of the inner layer.

[0039] In a catheter constructed according to this aspect, the distal end side of the first reinforcing member located proximal to the cross-sectionally varying portion is bonded to the surface of the inner layer, thereby suppressing deformation of the first reinforcing member at the proximal portion of the cross-sectionally varying portion. Therefore, even in cases where there is a large difference in deformation rigidity at the cross-sectionally varying portion or the first reinforcing member is discontinuous at the cross-sectionally varying portion, deformation in the cross-sectionally varying portion, in which the proximal end side of the first reinforcing member rides up onto the outer periphery of the distal end side, can be prevented when an insertion force is applied to the catheter from the proximal end to the distal end.

[0040] In particular, in a small-diameter catheter that is inserted to a more distal lesion, the length of the catheter and the first reinforcing member becomes long, and when the catheter is inserted into, for example, a peripheral blood vessel having a complex shape, torsional forces and the like are exerted in addition to the insertion operation force toward the distal end side. Therefore, in a small-diameter catheter, the proximal end side of the cross-sectionally changing portion of the first reinforcing member is more likely to ride up onto the distal end side, but by adopting the structure according to this aspect, it is possible to prevent the proximal end side of the cross-sectionally changing portion from riding up onto the distal end side.

[0041] In a fourteenth aspect, in the catheter described in the thirteenth aspect, the first reinforcing material located on the proximal end side of the cross-sectional change portion is a plate coil-shaped reinforcing material with a flat cross section.

[0042] A catheter constructed in accordance with this embodiment can employ a plate coil-shaped reinforcing material at the proximal end, which is advantageous for improving properties such as pushability, while effectively avoiding problems such as the cross-sectional change section riding over the first reinforcing material at the distal end.

[0043] In a fifteenth aspect, in the catheter described in the thirteenth or fourteenth aspect, the winding pitch is reduced at the tip of the first reinforcing material located on the proximal end side of the cross-sectionally changing section, and adjacent sections in the catheter length direction are welded to each other.

[0044] In a catheter constructed according to this embodiment, the shape stability of the tip of the first reinforcing material located on the proximal end side of the cross-sectionally changing section is enhanced by welding adjacent sections of the winding together, thereby preventing, for example, the proximal end side of the cross-sectionally changing section from riding up onto the distal end side, and preventing the catheter from bending (kinking) at the tip of the first reinforcing material located on the proximal end side of the cross-sectionally changing section.

[0045] According to the present invention, it becomes possible to insert a catheter into a body lumen such as a more distal small blood vessel.

[0046] FIG. 1 is a plan view showing a suction catheter according to a first embodiment of the present invention; FIG. 2 is a cross-sectional view showing an enlarged view of the tip portion of the suction catheter of FIG. 1, which corresponds to the II-II cross section of FIG. 3; FIG. 3 is an enlarged view of the III-III cross section of FIG. 2; FIG. 1 is a plan view of the suction catheter shown in FIG. 1 with the outer layer removed, showing an enlarged view of the boundary portion between the tip reinforcing fiber body and the base reinforcing fiber body; FIG. 1 is a plan view of the suction catheter shown in FIG. 1 with the outer layer and second reinforcing material removed, showing an enlarged view of the boundary portion between the plate coil reinforcing material and the wire coil reinforcing material.

[0047] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0048] Figure 1 shows a suction catheter 10 as a first embodiment of a catheter according to the present invention. The suction catheter 10 includes a catheter body 12. In the following description, the tip side generally refers to the left side in Figure 1, which is the distal end side, and the base side generally refers to the right side in Figure 1, which is the proximal end side. Furthermore, the axial direction refers to the left-right direction in Figure 1, which is the length direction of the catheter body 12, and the radial direction refers to the direction perpendicular to the left-right direction in Figure 1.

[0049] The catheter body 12 is a small-diameter, elongated tube that is capable of elastic bending deformation. As shown in Figures 2 and 3, the catheter body 12 has a lumen 16 that has a substantially circular cross section and runs through it in the longitudinal direction. The catheter body 12 has a tubular inner layer 18 that provides the inner circumferential surface of the lumen 16, and a tubular outer layer 20 that covers the inner layer 18 from the outer periphery.

[0050] The inner layer 18 is made of resin, for example, polytetrafluoroethylene (PTFE). In this embodiment, the inner layer 18 is entirely made of one type of resin material, but it may be made of multiple types of resin materials in the length direction, and in that case, it is desirable that the tip side be made of a resin material with a lower flexural modulus.

[0051] The outer layer 20 is made of resin. The outer layer 20 may be entirely made of a single type of resin material, but it is preferable that the outer layer 20 be made of multiple types of resin materials along the length. In this case, it is preferable that the distal end be made of a resin material with a lower flexural modulus. The resin material forming the outer layer 20 is not particularly limited, but may be, for example, polyamide, polyamide elastomer, polyurethane, or a synthetic resin material containing a mixture thereof. In this embodiment, the outer layer 20 is made of multiple types of resin along the length. From the proximal end to the distal end, the outer layer 20 is made of polyamide, polyamide elastomer, polyurethane, low-hardness polyurethane, and polyurethane. The outer layer 20, except for the tip portion 22 (described below) at the most distal end, which is made of polyurethane, is made of a resin material that is harder toward the proximal end.

[0052] The distal end portion of the outer layer 20 is a tip portion 22. The tip portion 22 has a tapered shape with the distal end portion becoming smaller in diameter toward the distal end. The tip portion 22 is integrally formed with the outer layer 20, with the base end portion positioned on the outer periphery of the distal end portion of the inner layer 18 and the distal end portion protruding distally beyond the inner layer 18. The wall surface of the lumen 16 is formed by the inner layer 18 and the tip portion 22. Note that the tip portion 22 may be a separate member from the outer layer 20, or may be fixed to the distal end sides of the inner layer 18 and the outer layer 20.

[0053] A radiopaque marker 24 is disposed at the tip portion of the inner layer 18. The radiopaque marker 24 is, for example, in the shape of a coil, and is attached in an externally inserted state to the tip portion of the inner layer 18, and is disposed between the inner layer 18 and the outer layer 20. The radiopaque marker 24 is formed of a metal such as gold, tungsten, or platinum.

[0054] A hard first reinforcing member 26 is disposed on the outer peripheral surface of the inner layer 18. The first reinforcing member 26 is formed in the shape of a coil that extends spirally as a whole. The first reinforcing member 26 is preferably made of metal, such as stainless steel or a nickel-titanium (Ni-Ti) alloy. The first reinforcing member 26 of this embodiment is composed of a plate coil-shaped reinforcing member 28 and a wire coil-shaped reinforcing member 30.

[0055] The plate coil reinforcing member 28 has a substantially uniform rectangular flat cross section and extends spirally on the outer peripheral surface of the inner layer 18. The cross-sectional shape of the plate coil reinforcing member 28 is a flat rectangular shape with a radial thickness dimension smaller than its axial length dimension. The plate coil reinforcing member 28 constitutes the base end portion of the first reinforcing member 26. The plate coil reinforcing member 28 is desirably made of metal, and is preferably formed of stainless steel, which has greater deformation rigidity than when formed of a Ni-Ti alloy.

[0056] The wire coil reinforcing member 30 is composed of a flat-bundle wire 34, in which multiple wire rods 32 with approximately circular cross sections are arranged flat in the axial direction, and extends helically on the outer circumferential surface of the inner layer 18. The number of wire rods 32 constituting the flat-bundle wire 34 is appropriately selected taking into account the required strength (reinforcing effect, described below), etc., and is not particularly limited. However, taking into account the bending deformation rigidity required of the catheter and handling during manufacturing, it is desirable for the number to be in the range of 2 to 5, for example, and in this embodiment, it is 3. Note that the multiple wire rods 32 may be bundled with an adhesive or may be independently wound helically around the outer circumferential surface of the inner layer 18. Furthermore, the cross-sectional shape of the wire rods 32 is desirably circular, but is not particularly limited thereto. The wire coil reinforcing member 30 constitutes the distal end portion of the first reinforcing member 26. The wire coil reinforcing member 30 is desirably made of metal, and is preferably composed of wire rods 32 made of a Ni-Ti alloy, which has lower rigidity than wire rods made of stainless steel.

[0057] As shown in Figures 2 and 5, the plate coil-shaped reinforcement member 28 and the wire coil-shaped reinforcement member 30 are arranged side by side in the longitudinal direction of the inner layer 18. That is, the plate coil-shaped reinforcement member 28 is located closer to the base end (proximal end) than the wire coil-shaped reinforcement member 30. The distal end of the plate coil-shaped reinforcement member 28 and the proximal end of the wire coil-shaped reinforcement member 30 are continuously arranged in an axially abutting relationship without overlapping each other. The boundary between the plate coil-shaped reinforcement member 28 and the wire coil-shaped reinforcement member 30 in the first reinforcement member 26 forms a cross-sectionally varying portion 36 whose cross-sectional shapes differ between the proximal end and distal end in the longitudinal direction of the catheter body 12. In other words, the proximal end side of the cross-sectionally varying portion 36 of the first reinforcement member 26 is constituted by the plate coil-shaped reinforcement member 28, and the distal end side of the cross-sectionally varying portion 36 is constituted by the wire coil-shaped reinforcement member 30. In addition, the phrase "the distal end of the plate coil-shaped reinforcement material 28 and the proximal end of the wire coil-shaped reinforcement material 30 are continuously arranged in a butted state" does not necessarily mean that the distal end of the plate coil-shaped reinforcement material 28 and the proximal end of the wire coil-shaped reinforcement material 30 are butted together in an abutting state. Even if they are spaced apart as shown in Figures 2 and 5, it is sufficient that the plate coil-shaped reinforcement material 28 and the wire coil-shaped reinforcement material 30 are substantially continuously coiled without being significantly separated compared to the respective winding pitches.

[0058] As shown in FIG. 5 , adjacent portions of the distal end of the plate coil reinforcing member 28 are welded to each other in the catheter length direction. The plate coil reinforcing member 28 of this embodiment is made of metal, and the welds 38 connecting the windings in the distal end are formed by welding, such as laser welding. The welded distal end of the plate coil reinforcing member 28 has a smaller winding pitch than the other portions of the plate coil reinforcing member 28. As described above, the distal end of the plate coil reinforcing member 28 has a smaller winding pitch and adjacent portions are welded to each other at the welds 38. This limits the amount of deformation of the distal end of the plate coil reinforcing member 28 compared to the other portions, thereby improving shape stability. The distal end of the plate coil reinforcing member 28 may be partially welded at multiple locations in the circumferential direction, or may be continuously welded over a length of one or more revolutions in the circumferential direction. While the present embodiment illustrates an example in which there are gaps between the windings in the distal end of the plate coil reinforcing member 28, for example, the windings in the distal end of a tightly wound plate coil reinforcing member 28 without any gaps may be welded. For example, the weld 38 may be provided to weld between the windings at the distal end of the plate coil reinforcing member 28 as well as between the windings at the proximal end of the wire coil reinforcing member 30. In short, the plate coil reinforcing member 28 and the wire coil reinforcing member 30 may be connected to each other by the weld 38.

[0059] In the first reinforcing member 26, the distal end portion of the plate coil-shaped reinforcing member 28 located on the proximal end side of the cross-sectionally changing portion 36 is bonded to the surface of the inner layer 18 with an adhesive 39. By bonding the distal end portion of the plate coil-shaped reinforcing member 28 to the inner layer 18, the relative displacement of the distal end portion of the plate coil-shaped reinforcing member 28 with respect to the inner layer 18 is limited. For example, the adhesive 39 is applied while the first reinforcing member 26 and a base reinforcing fiber body 46 of a second reinforcing member 40 (described later) are disposed on the outer peripheral surface of the inner layer 18, and the base reinforcing fiber body 46 is also bonded with the adhesive 39 in addition to the first reinforcing member 26 and the inner layer 18. The adhesive 39 bonding the inner layer 18 and the plate coil-shaped reinforcing member 28 is not particularly limited, but is preferably one that has elasticity after curing, such as a copolymer polyamide adhesive. The adhesive 39 may also bond not only the distal end portion of the plate coil-shaped reinforcing member 28 but also the base end portion of the wire coil-shaped reinforcing member 30 to the inner layer 18, etc.

[0060] The first reinforcing member 26 is attached in an externally fitted state onto the outer peripheral surface of the inner layer 18, and is covered from the outer peripheral side by the outer layer 20. As a result, the first reinforcing member 26 is disposed in an embedded state without being exposed to the outside in the peripheral wall of the lumen 16 formed by the inner layer 18 and the outer layer 20. The first reinforcing member 26 is disposed on the proximal side of the contrast marker 24.

[0061] A soft second reinforcing member 40 is disposed on the peripheral wall of the lumen 16, which is formed by the inner layer 18 and the outer layer 20. As shown in FIGS. 3 and 4 , the second reinforcing member 40 is formed, for example, of fibers 42 extending in a crosswise manner and is made of a softer material than the first reinforcing member 26. The second reinforcing member 40 is formed, for example, of resin fibers 42, and is formed by arranging the fibers 42 in a double spiral or by braiding the fibers 42 to form a braid. The specific material for the fibers 42 is not particularly limited, but suitable synthetic fibers include polyamide, polyester, and polyacrylonitrile. The second reinforcing member 40 of this embodiment has a structure in which a plurality of flat-bundle cords 44, each of which is formed by arranging a plurality of fibers 42 flat, are arranged crosswise.

[0062] 2 and 4, the proximal end side of the second reinforcing material 40 is a base reinforcing fiber body 46 made up of flat bundle cords 44a with a large number of fibers 42. The distal end side of the second reinforcing material 40 is a tip reinforcing fiber body 48 made up of flat bundle cords 44b with a small number of fibers 42. In short, the second reinforcing material 40 has a base reinforcing fiber body 46 and a tip reinforcing fiber body 48, which are regions where the numbers of fibers 42 of the flat bundle cords 44 are different, and the number of fibers 42 making up the flat bundle cords 44 is smaller at the distal end side than at the proximal end side in the catheter length direction.

[0063] The number of fibers 42 in the flat bundle cords 44a constituting the base reinforcing fiber body 46 and the number of fibers 42 in the flat bundle cords 44b constituting the tip reinforcing fiber body 48 are not particularly limited, as long as the number of fibers 42 in the flat bundle cords 44a is greater than the number of fibers 42 in the flat bundle cords 44b. In this embodiment, for example, the number of fibers 42 constituting the flat bundle cords 44a of the base reinforcing fiber body 46 is 14, and the number of fibers 42 constituting the flat bundle cords 44b of the tip reinforcing fiber body 48 is 7. For ease of viewing, a small number of fibers 42 are shown in Figures 2 and 3, and the fibers 42 are omitted in Figure 4. For ease of viewing, the cross-sectional size of the fibers 42 and the width of the flat bundle cords 44 are appropriately enlarged in each figure.

[0064] The base reinforcing fiber body 46 and the tip reinforcing fiber body 48 also differ in the distance in the catheter length direction between adjacent flat bundle cords 44. That is, the base reinforcing fiber body 46 has more flat bundle cords 44a than the flat bundle cords 44b of the tip reinforcing fiber body 48, and in this embodiment, the base reinforcing fiber body 46 has 16 flat bundle cords 44a and the tip reinforcing fiber body 48 has 8 flat bundle cords 44b. As a result, the distance between the flat bundle cords 44a of the base reinforcing fiber body 46 is narrower than the distance between the flat bundle cords 44b of the tip reinforcing fiber body 48. In this embodiment, the number of flat bundle cords 44a in the base reinforcing fiber body 46 is twice the number of flat bundle cords 44b in the tip reinforcing fiber body 48, and therefore the distance between the flat bundle cords 44a in the base reinforcing fiber body 46 is approximately half the distance between the flat bundle cords 44b in the tip reinforcing fiber body 48.

[0065] The fibers 42 constituting the flat-bundle cords 44a of the base reinforcing fiber body 46 and the fibers 42 constituting the flat-bundle cords 44b of the tip reinforcing fiber body 48 are separate fibers that are not continuous with each other. As will be described later, the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 of this embodiment are each formed separately and are braided bodies that are independent of each other.

[0066] 2, the tip end portion of the base reinforcing fiber body 46 and the base end portion of the tip reinforcing fiber body 48 overlap each other when the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 are disposed between the inner layer 18 and the outer layer 20. That is, the base reinforcing fiber body 46 extends further toward the tip side (distal end side) than the base end of the tip reinforcing fiber body 48, and the tip end portions of the fibers 42 constituting the flat bundle cords 44a of the base reinforcing fiber body 46 and the base end portions of the fibers 42 constituting the flat bundle cords 44b of the tip reinforcing fiber body 48 overlap each other in the radial direction of the catheter body 12. It is desirable that the overlap portion between the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 be provided around the entire circumference of the catheter body 12.

[0067] The base reinforcing fiber body 46 is disposed, for example, on the outer peripheral surface of the first reinforcing material 26, which is spirally wound around the outer peripheral surface of the inner layer 18. Meanwhile, the tip reinforcing fiber body 48 is fixed to the inner peripheral surface of a resin tube that forms the outer layer 20. Then, a resin tube to which the tip reinforcing fiber body 48 is attached is inserted over the inner layer 18 to which the first reinforcing material 26 and the base reinforcing fiber body 46 are attached, and the overlapping surfaces of the inner layer 18 and the resin tube are welded. In this way, the outer layer 20 is formed in which the inner layer 18, the first reinforcing material 26, and the base reinforcing fiber body 46 are respectively fixed, and the tip reinforcing fiber body 48 is disposed in an inserted state over the inner layer 18. The first reinforcing material 26 and the second reinforcing material 40 are provided in a buried state in the peripheral wall of the lumen 16 formed by the inner layer 18 and the outer layer 20, without being exposed to the outside. As can be seen from the fact that the base reinforcing fiber body 46 is attached to the inner layer 18 side and the tip reinforcing fiber body 48 is attached to the outer layer 20 side, the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 are separate components, and the fibers 42 that make up the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 are not continuous.

[0068] By positioning and welding the inner layer 18 and the resin tube so that the distal end portion of the base reinforcing fibrous body 46 and the proximal end portion of the tip reinforcing fibrous body 48 overlap each other, it is possible to make the distal end portion of the base reinforcing fibrous body 46 and the proximal end portion of the tip reinforcing fibrous body 48 overlap each other in the catheter body 12. Note that, for example, the fibers 42 constituting the base reinforcing fibrous body 46 and the fibers 42 constituting the tip reinforcing fibrous body 48 can also be welded to each other by heating when welding the inner layer 18 and the outer layer 20. The fibers 42 constituting the base reinforcing fibrous body 46 and the fibers 42 constituting the tip reinforcing fibrous body 48 may also be bonded to each other with an adhesive.

[0069] The second reinforcing material 40 is not provided in the distal region 50 of the catheter body 12, including the tip section 22, and the tip reinforcing fiber body 48 is provided in the intermediate region 52 of the catheter body 12. Therefore, the content (area ratio) of the fibers 42 of the second reinforcing material 40 in the cross section shown in Figure 3 is set to be smaller in the distal region 50 of the catheter body 12 without the second reinforcing material 40 than in the proximal region 54 of the catheter body 12 with the base reinforcing fiber body 46. Furthermore, the intermediate region 52 of the catheter body 12 with the tip reinforcing fiber body 48 is a transition region in which the content of the fibers 42 of the second reinforcing material 40 in the cross section is set between the proximal region 54 of the catheter body 12 with the base reinforcing fiber body 46 and the distal region 50 of the catheter body 12 with the second reinforcing material 40.

[0070] (a) The boundary portion (cross-sectional change portion 36) between the plate coil-shaped reinforcement material 28 and the wire coil-shaped reinforcement material 30, (b) the connection portion between the base reinforcement fiber body 46 and the tip reinforcement fiber body 48 in the second reinforcement material 40, and (c) the tip of the tip reinforcement fiber body 48 in the second reinforcement material 40 are arranged in this order from the base end side of the catheter body 12.

[0071] A coating layer may be provided on the outer peripheral surface of the outer layer 20 of the catheter body 12. By providing a coating layer, the coefficient of friction of the outer peripheral surface of the catheter body 12 is reduced, thereby improving insertion into a blood vessel. As the coating layer, known coatings such as a hydrophilic coating, a fluororesin coating, or a silicone coating may be used. The coating layer may be provided over the entire length of the catheter body 12, or may be provided over a predetermined length from the tip of the catheter body 12 that is less than the entire length, with no coating layer provided on the proximal end.

[0072] As shown in Fig. 1, a hub 56 is attached to the proximal end of the catheter main body 12 having such a structure. The hub 56 is made of hard resin or metal, and its proximal end is connected to an external circuit (not shown), thereby connecting the lumen 16 of the catheter main body 12 to the external circuit. The specific structure of the hub 56 is not particularly limited, but the hub 56 of this embodiment is integrally provided with a tubular portion 58 connected to the proximal end of the catheter main body 12 and a plurality of operating wings 60 protruding radially outward from the tubular portion 58. A strain relief 62 is attached to the end of the catheter main body 12 on the hub 56 side to prevent kinking of the catheter main body 12.

[0073] The aspiration catheter 10 is used, for example, to aspiration thrombi in cerebral blood vessels. In this case, a negative pressure pump for aspiration (not shown) that applies negative pressure to the lumen 16 is connected to the hub 56 via an external circuit. Then, for example, the catheter main body 12 is percutaneously inserted into a blood vessel from the leg or the like, and the distal end of the catheter main body 12 is delivered to an affected area of ​​the cerebral blood vessel, where the thrombi are aspirated from the distal opening of the lumen 16.

[0074] Here, the aspiration catheter 10 has a catheter body 12 that is long enough to reach the cerebral blood vessels, and a small diameter at the tip of the catheter body 12 so that it can be inserted into narrow cerebral blood vessels. Furthermore, because the deep parts of cerebral blood vessels are complexly curved, the tip of the catheter body 12 must also be flexible enough to follow the complex shapes of the cerebral blood vessels. Therefore, the aspiration catheter 10 has multiple configurations to achieve the required performance as described above.

[0075] In other words, the suction catheter 10 is provided with a first reinforcing member 26 for ensuring the deformation rigidity of the catheter body 12 and enhancing pushability, thereby making it possible to push the catheter body 12 toward the distal end even if the catheter body 12 is long.

[0076] The proximal end side of the first reinforcing member 26 is made up of a plate coil-shaped reinforcing member 28 with a flat cross section, which allows for excellent reinforcing action at the proximal end side. On the other hand, the distal end side of the first reinforcing member 26 is made up of a wire coil-shaped reinforcing member 30 with a circular cross section, which allows for high flexibility at the distal end side. In this way, the aspiration catheter 10 has different cross-sectional shapes of the first reinforcing member 26 at the proximal and distal ends, which allows for the excellent pushability and kink resistance required at the proximal end side to be achieved while also allowing for the excellent flexibility (ability to conform to a blood vessel) required at the distal end side.

[0077] The wire coil reinforcing member 30 has a structure in which a flat bundle wire 34, which is made up of three wire rods 32, 32, 32 arranged flat, extends in a spiral shape. This makes it easy to adjust the balance between the deformation rigidity and flexibility of the wire coil reinforcing member 30, and also makes it possible to reduce the outer diameter of the wire coil reinforcing member 30. In addition, the plate coil reinforcing member 28 has a flat rectangular cross section with a small radial thickness, so that the deformation rigidity and flexibility can be appropriately set while the outer diameter can be reduced.

[0078] By arranging the plate coil-shaped reinforcement material 28 and the wire coil-shaped reinforcement material 30 continuously in a butt-to-butt state without overlapping each other, it is possible to prevent the stiffness of the catheter main body 12 from increasing at the connection portion (cross-sectional change portion 36) between the plate coil-shaped reinforcement material 28 and the wire coil-shaped reinforcement material 30, and it is also possible to prevent the catheter main body 12 from becoming large in diameter.

[0079] Since the plate coil-shaped reinforcing member 28 and the wire coil-shaped reinforcing member 30 that make up the first reinforcing member 26 are each made of metal, the winding of the first reinforcing member 26 can be made small in diameter while ensuring the deformation rigidity of the first reinforcing member 26, thereby preventing the catheter main body 12 from becoming larger in diameter.

[0080] The tip portion of the plate coil reinforcing member 28 is bonded to the surface of the inner layer 18, limiting the amount of displacement relative to the inner layer 18. This prevents, for example, unintended displacement of the tip portion of the plate coil reinforcing member 28, such as riding up onto the outer periphery of the base end portion of the wire coil reinforcing member 30, when a pushing force from the proximal end side to the distal end side acts on the catheter body 12.

[0081] The distal end portion of the plate coil-shaped reinforcing member 28 has a smaller pitch between windings than the other portions, and adjacent portions in the longitudinal direction of the catheter main body 12 are welded to each other, making the distal end portion of the plate coil-shaped reinforcing member 28 more rigid than the other portions. This makes it less likely that the distal end portion of the plate coil-shaped reinforcing member 28 will deform onto the outer periphery of the base end portion of the wire coil-shaped reinforcing member 30 when a force is applied to the catheter main body 12 pushing it from the proximal end side to the distal end side. This makes it possible to prevent unintended deformation and displacement of the first reinforcing member 26 at the cross-sectionally changing portion 36, which is the connection portion between the plate coil-shaped reinforcing member 28 and the wire coil-shaped reinforcing member 30.

[0082] The suction catheter 10 is provided with a second reinforcing member 40 for ensuring the deformation rigidity of the catheter body 12 and further enhancing pushability, thereby making it possible to push the catheter body 12 toward the distal end even if the catheter body 12 is long.

[0083] The second reinforcing material 40 has a structure in which a plurality of flat bundle cords 44, each made of a plurality of fibers 42 arranged flat, are arranged in a cross-like pattern. This effectively obtains the reinforcing effect of the second reinforcing material 40 while preventing the catheter body 12 from becoming larger in diameter due to the second reinforcing material 40.

[0084] Since the number of fibers 42 in the flat bundle cords 44 that make up the second reinforcing material 40 varies along the length of the catheter body 12, the balance of the reinforcing effect of the second reinforcing material 40 along the length of the catheter body 12 can be easily adjusted by the number of fibers 42 in the flat bundle cords 44.

[0085] In this embodiment, the number of fibers 42 in the flat bundle cords 44b constituting the tip reinforcing fiber body 48 of the second reinforcing material 40 located on the distal end side of the catheter body 12 is made fewer than the number of fibers 42 in the flat bundle cords 44a constituting the base reinforcing fiber body 46 of the second reinforcing material 40 located on the proximal end side of the catheter body 12. Therefore, the reinforcing effect of the second reinforcing material 40 can be greatly obtained on the proximal end side, where pushability and kink resistance are particularly required, and the reinforcing effect of the second reinforcing material 40 is suppressed on the distal end side, where flexibility is particularly required, thereby achieving excellent conformability to the shape of the blood vessel.

[0086] The fibers 42 of the flat bundle cords 44a constituting the base reinforcing fiber body 46 and the fibers 42 of the flat bundle cords 44b constituting the tip reinforcing fiber body 48 are discontinuous fibers, which makes it possible to easily form the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 having different numbers of fibers 42.

[0087] Because the distal end portion of the base reinforcing fiber body 46 and the proximal end portion of the tip reinforcing fiber body 48 overlap each other, even if the fibers 42 of the base reinforcing fiber body 46 and the fibers 42 of the tip reinforcing fiber body 48 are discontinuous fibers, it is possible to prevent the creation of an area without the second reinforcing material 40 at the boundary between the base reinforcing fiber body 46 and the tip reinforcing fiber body 48. This makes it possible to prevent kinking of the catheter main body 12 at the boundary between the base reinforcing fiber body 46 and the tip reinforcing fiber body 48. Note that, because the fibers 42 of the second reinforcing material 40 in this embodiment have a significantly smaller diameter than the winding of the first reinforcing material 26, an increase in diameter at the overlapping portion is unlikely to be a problem.

[0088] Both the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 have a braided structure in which a plurality of flat bundle cords 44 arranged in a crossing pattern are braided together, thereby making it possible to advantageously obtain the reinforcing effect of the second reinforcing member 40.

[0089] The distal region 50 of the catheter body 12 is not provided with the second reinforcing material 40, and has a smaller content of fibers 42 in the cross section than the proximal region 54 of the catheter body 12, which is provided with the base reinforcing fiber body 46 of the second reinforcing material 40. This ensures high flexibility on the distal side of the catheter body 12, while achieving excellent pushability and kink resistance on the proximal side of the catheter body 12.

[0090] Furthermore, the intermediate region 52 located between the distal region 50 and the proximal region 54 of the catheter body 12 is provided with the distal reinforcing fiber body 48 of the second reinforcing material 40, and serves as a transition region in which the content of the fibers 42 in the cross section is set between the distal region 50 and the proximal region 54. The provision of such a transition region suppresses sudden changes in the stiffness of the catheter body 12 and reduces stress concentration at the site of stiffness change in the catheter body 12, thereby achieving smooth bending deformation in the catheter body 12 and efficient transmission of pushing force to the distal side.

[0091] The suction catheter 10 not only aspirates thrombi and the like from the distal opening of the lumen 16, but also injects a contrast medium into a blood vessel through the lumen 16. During such contrast medium injection, if the distal opening of the lumen 16 is blocked by a thrombus, a blood vessel wall, or the like, the pressure within the lumen 16 may increase, causing an outward force to act on the peripheral wall of the lumen 16. In such cases, the provision of a hard first reinforcing member 26 on the peripheral wall of the lumen 16 suppresses radial expansion and deformation of the peripheral wall of the lumen 16, thereby avoiding damage to the blood vessel caused by the peripheral wall being pressed against the wall. In this embodiment, the first reinforcing member 26 is composed of a metal plate coil-shaped reinforcing member 28 and a wire coil-shaped reinforcing member 30, and therefore the first reinforcing member 26 has high rigidity, making it easy to ensure pressure resistance to the positive pressure in the lumen 16 during contrast imaging. Furthermore, the wire coil reinforcing member 30, which has lower deformation rigidity and better flexibility than the plate coil reinforcing member 28, is configured with a flat bundle of wires 34 formed by arranging three wires 32, 32, 32 in a flat manner, thereby ensuring the necessary pressure resistance. Note that the second reinforcing member 40 disposed on the outer periphery of the first reinforcing member 26 also suppresses the radial expansion and deformation of the peripheral wall of the lumen 16.

[0092] The catheter main body 12 has, arranged in this order from the proximal end, (a) the boundary portion (cross-sectional change portion 36) between the plate coil-shaped reinforcement member 28 and the wire coil-shaped reinforcement member 30, (b) the connection portion between the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 in the second reinforcement member 40, and (c) the tip of the tip reinforcing fiber body 48 in the second reinforcement member 40. As a result, (a) and (b), at which a change in hardness of the catheter main body 12 occurs, are positioned offset from each other in the longitudinal direction of the catheter main body 12, which makes it possible to suppress a rapid change in hardness of the catheter main body 12 compared to when (a) and (b) are positioned at the same position. In particular, because (a), where a larger change in hardness is likely to occur, is located closer to the proximal end than (b), it is possible to suppress a change in hardness at the tip end, which has a smaller diameter and where the reinforcing effects of the first reinforcing member 26 and the second reinforcing member 40 are more pronounced. Furthermore, (a) is covered and reinforced from the outer periphery by the base reinforcing fiber body 46, which has a higher fiber density and exhibits a stronger reinforcing effect than the tip reinforcing fiber body 48, and therefore in (a) where the change in hardness of the catheter body 12 is relatively large, the rate of hardness change due to the first reinforcing material 26 is suppressed, preventing kinking (breaking) of the catheter body 12. Furthermore, because (a) is covered from the outer periphery by the base reinforcing fiber body 46, the radial expansion and deformation of the tip portion of the plate coil reinforcing material 28 is limited, and therefore, for example, it can be expected to have the effect of preventing the tip portion of the plate coil reinforcing material 28 from deforming so as to ride up onto the outer periphery of the base end portion of the wire coil reinforcing material 30 in (a).

[0093] Furthermore, in the second reinforcing material 40, (b) the connection portion between the base reinforcing fiber body 46 and the tip reinforcing fiber body 48 is located closer to the base end of the catheter body 12 than (c) the tip of the tip reinforcing fiber body 48, and the reinforcing effect of the second reinforcing material 40 gradually decreases toward the tip. Therefore, when the second reinforcing material 40 is removed (c), a sudden change in hardness of the catheter body 12 can be suppressed.

[0094] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific description. For example, the first reinforcing member is not necessarily limited to a coil shape, but may be a braided structure in which wires having any cross-sectional shape are woven in a cross-like pattern, or may have a structure in which multiple rings are partially connected in the circumferential direction by means of welding or the like. Furthermore, the second reinforcing member is not necessarily limited to a braided structure, but may have, for example, a double-spiral wound structure.

[0095] In the first embodiment, the first reinforcing member 26 is formed of two coil-shaped reinforcing members, the plate coil-shaped reinforcing member 28 and the wire coil-shaped reinforcing member 30, which have different cross-sectional shapes. However, the first reinforcing member may also be formed of, for example, three or more types of coil-shaped reinforcing members each having a different cross-sectional shape. In this case, it is desirable that the coil-shaped reinforcing member located closer to the tip has a smaller deformation rigidity.

[0096] The first reinforcing member may be composed of wire coil reinforcing members, with some or all of the coil reinforcing members being made of wire. In this case, it is desirable to make the cross-sectional area of ​​the distal coil reinforcing member smaller than that of the proximal coil reinforcing member, for example, by decreasing the number of wires or decreasing the diameter of the wires in the distal coil reinforcing member. The entire first reinforcing member may be a plate coil reinforcing member with a flat cross section, and in this case, it is also desirable to make the distal side have a smaller cross-sectional area than the proximal side. Furthermore, the cross-sectional shape of the coil reinforcing member constituting the first reinforcing member is not limited to either the circular or rectangular shape shown in the above embodiment, and any cross-sectional shape can be used.

[0097] In the first embodiment, the second reinforcing material 40 is formed of two reinforcing fiber bodies, the base reinforcing fiber body 46 and the tip reinforcing fiber body 48, each having a different number of fibers 42. However, the second reinforcing material may also be formed of, for example, three or more types of reinforcing fiber bodies each having a different number of fibers. In this case, it is desirable that the number of fibers in the reinforcing fiber body located closer to the distal end be fewer. In other words, in the second reinforcing material, an intermediate reinforcing fiber body, whose fiber number is set between the base reinforcing fiber body and the tip reinforcing fiber body, may be provided between the base reinforcing fiber body located closest to the proximal end and the tip reinforcing fiber body located closest to the distal end and the tip reinforcing fiber body located closest to the distal end. In this case, the intermediate reinforcing fiber body, together with the tip reinforcing fiber body, forms a transition region in the cross section of the catheter body, whose fiber content is set between the fiber content of the distal region without any reinforcing fiber body and the fiber content of the proximal region where the base reinforcing fiber body is located.

[0098] The structure of the first reinforcing material 26 including the plate coil-shaped reinforcing material 28 on the proximal end side and the wire coil-shaped reinforcing material 30 on the distal end side, and the structure of the second reinforcing material 40 including the base reinforcing fiber body 46 on the proximal end side and the tip reinforcing fiber body 48 on the distal end side, do not necessarily need to be adopted in combination; it is also possible to adopt only one of them. That is, the first reinforcing material 26 according to the first embodiment including the plate coil-shaped reinforcing material 28 on the proximal end side and the wire coil-shaped reinforcing material 30 on the distal end side may be combined with a conventional second reinforcing material having a constant number of fibers 42. Furthermore, the second reinforcing material 40 according to the first embodiment including the base reinforcing fiber body 46 on the proximal end side and the tip reinforcing fiber body 48 on the distal end side may be combined with a conventional first reinforcing material extending spirally with a constant cross-sectional shape.

[0099] The present invention is not limited to being applied to suction catheters used for suctioning thrombi and the like, but can also be applied to various known catheters, such as catheters used for delivering medicinal solutions or stents to lesions, balloon catheters with a balloon at the tip, and measurement catheters for measuring the concentration of nitric oxide and the like in the blood.

[0100] REFERENCE SIGNS LIST 10 Suction catheter (first embodiment catheter) 12 Catheter body 16 Lumen 18 Inner layer 20 Outer layer 22 Tip portion 24 Radiopaque marker 26 First reinforcing material 28 Plate coil-shaped reinforcing material 30 Wire coil-shaped reinforcing material 32 Wire material 34 Flat bundled wire 36 Cross-sectionally changed portion 38 Welded portion 39 Adhesive 40 Second reinforcing material 42 Fiber 44 (44a, 44b) Flat bundled cord 46 Base reinforcing fiber body 48 Tip reinforcing fiber body 50 Tip region 52 Intermediate region (transition region) 54 Base end region 56 Hub 58 Cylindrical portion 60 Operating wing portion 62 Strain relief

Claims

1. A catheter having a lumen extending in the longitudinal direction, wherein a first rigid reinforcing material extending in a spiral shape is embedded in the peripheral wall of the lumen, and the first reinforcing material includes a plate-like coil reinforcing material with a flat cross section located on the proximal end side in the longitudinal direction, and a wire-like coil reinforcing material with a circular cross section located on the distal end side of the plate-like coil reinforcing material.

2. A catheter according to claim 1, wherein the wire coil reinforcing member has a structure in which a flat bundle of wires, consisting of a plurality of wires arranged flat in the length direction of the catheter, extends in a spiral shape.

3. A catheter according to claim 1 or 2, wherein the plate coil reinforcing member and the wire coil reinforcing member are arranged continuously in a butt-to-butt relationship in the lengthwise direction of the catheter without overlapping each other.

4. A catheter according to claim 1 or 2, wherein the plate coil reinforcing member and the wire coil reinforcing member are both made of metal.

5. A catheter as claimed in claim 1 or 2, wherein a soft second reinforcing material extending in a crosswise manner is embedded in the peripheral wall of the lumen, said second reinforcing material being constructed of a plurality of flat bundle cords, each of which is made of a plurality of fibers arranged flat, and which are arranged in a crosswise manner, and the number of fibers in said flat bundle cords constituting said second reinforcing material varies along the length of the catheter.

6. A catheter according to claim 1 or 2, comprising a tubular inner layer that provides the inner circumferential surface of the lumen, and a tubular outer layer that outer circumferentially covers the inner layer and the first reinforcing material, wherein the plate coil reinforcing material and the wire coil reinforcing material that constitute the first reinforcing material are arranged continuously in the length direction of the catheter, so that the first reinforcing material has a cross-sectionally varying portion, and the tip side of the plate coil reinforcing material located on the proximal end side of the cross-sectionally varying portion is adhered to the surface of the inner layer.

7. A catheter having a lumen extending in the longitudinal direction, wherein a soft second reinforcing material extending in a crosswise manner is embedded in the peripheral wall of the lumen, the second reinforcing material is structured such that a plurality of flat bundle cords, each of which is made of a plurality of fibers arranged flat, are arranged in a crosswise manner, and the number of fibers in the flat bundle cords constituting the second reinforcing material varies along the length of the catheter.

8. The catheter according to claim 7, wherein the second reinforcing member has a braided structure in which a plurality of said flat bundle cords arranged crosswise to one another are braided together.

9. A catheter according to claim 7 or 8, wherein the number of fibers in the flat bundle cords constituting the second reinforcing member is smaller on the distal end side than on the proximal end side in the length direction of the catheter.

10. A catheter as described in claim 7 or 8, wherein, in regions along the length of the catheter where the number of fibers in the flat bundle cords constituting the second reinforcing material is different, the fibers in the flat bundle cords are separate fibers that are not continuous with each other.

11. A catheter as described in claim 10, wherein at the boundary between regions in the length direction of the catheter where the number of fibers in the flat bundle cords constituting the second reinforcing member is different, the ends of the fibers constituting the flat bundle cords in both regions overlap each other.

12. A catheter having a lumen extending in the longitudinal direction, wherein a soft second reinforcing material extending in a crosswise manner is embedded in the peripheral wall of the lumen, the second reinforcing material having a structure in which a plurality of flat bundle cords each made of a plurality of fibers arranged flatly are arranged in a crosswise manner, the content of the fibers constituting the flat bundle cords on the cross section of the catheter is set to be smaller at the distal end side than at the proximal end side in the longitudinal direction of the catheter, and a transition region is provided in the middle part in the longitudinal direction where the content of the fibers is set between the proximal end side and the distal end side.

13. A catheter with a lumen extending in the longitudinal direction, comprising: a tubular inner layer that provides the inner circumferential surface of the lumen; a hard first reinforcing member that extends spirally along the surface of the inner layer; and a tubular outer layer that outer circumferentially covers the inner layer and the first reinforcing member, wherein the first reinforcing member has a cross-sectionally varying portion having a different cross-sectional shape on the proximal end side and the distal end side in the longitudinal direction of the catheter, and the tip side of the first reinforcing member located on the proximal end side of the cross-sectionally varying portion is adhered to the surface of the inner layer.

14. A catheter according to claim 13, wherein the first reinforcing member located on the proximal end side of the cross-sectionally changing section is a plate-like coil reinforcing member having a flat cross section.

15. A catheter as described in claim 13 or 14, wherein the winding pitch is reduced at the tip of the first reinforcing material located on the proximal end side of the cross-sectionally changing section, and adjacent sections in the length direction of the catheter are welded to each other.

Images