Catheter

Abstract

To provide a catheter capable of easily expanding a balloon, reducing an influence on a blood flow, and improving expansion force to an intracorporeal lumen wall such as a blood vessel wall.SOLUTION: The catheter 1 includes a hollow outer shaft 9 having a first cavity portion 9g, an inner shaft 7 movably inserted into the first cavity portion 9g of the outer shaft 9 and extending from a distal end of the outer shaft 9 to a distal side, an inflatable and deflatable balloon 3 having a second cavity portion 3g and having a distal end connected to a distal end portion of the inner shaft 7 and a proximal end connected to the outer shaft 9 and wound around an outer periphery of the inner shaft 7 from the distal end of the outer shaft 9 to the distal side, and a wire 5 inserted into the second cavity portion 3g of the balloon 3.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a catheter that is inserted into a lumen such as a blood vessel of a patient. [Background technology]

[0002] Catheters that are inserted into lumens such as blood vessels of a patient have been known for some time. The doctor performing the procedure inserts a guidewire into the lumen of the catheter, causes the tip of the guidewire to protrude from the tip of the catheter, guides the catheter to the lesion along the guidewire, and places a device such as a stent or an embolization coil into the lesion through the lumen of the catheter that has reached the lesion.

[0003] For example, Patent Document 1 is recognized to describe a catheter comprising a tube 10 and a balloon 18 spirally wound around the outer periphery of the tip of the tube 10 (see FIG. 1, etc.), and is recognized to describe inserting this catheter into a patient's blood vessel 26, allowing it to enter a thrombus 28, and then expanding the balloon 18 to grasp the thrombus 28 and remove the thrombus 28 from the patient's blood vessel 26.

[0004] Patent document 1 is also recognized to describe a catheter 10d and a catheter equipped with a spiral balloon 50 consisting of an inner layer 54 and an outer layer 56 on the outer periphery of the tip of the catheter 10d (see FIG. 13, etc.), and is recognized to describe inserting this catheter into a patient's blood vessel 26 to dilate the blood vessel. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 4,762,130 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the catheter described in Patent Document 1 has a problem in that the balloon is made of a flexible material and therefore is unable to apply sufficient expansion force to the patient's blood vessel wall.

[0007] Furthermore, the catheter described in Patent Document 1 has a problem in that the patient's blood vessels are blocked when the balloon is inflated, which has a significant effect on the patient's blood flow.

[0008] Furthermore, it is generally desirable for a catheter to have an easy to expand balloon.

[0009] The present invention has been made in response to the above-mentioned problems of the prior art, and aims to provide a catheter that allows the balloon to be easily inflated, has little effect on blood flow, and has improved expansion force against the walls of internal lumens such as blood vessel walls. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, a catheter of a first aspect of the present invention is characterized by comprising: a hollow outer shaft having a first gap; an inner shaft that is movably inserted into the first gap of the outer shaft and extends from the tip of the outer shaft toward the tip; an expandable balloon that has a second gap, a tip connected to the tip of the inner shaft, a base end connected to the outer shaft, and is wound around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip; and a wire inserted into the second gap of the balloon.

[0011] A second aspect of the present invention is the catheter of the first aspect, wherein the outer shaft has a third cavity portion that communicates with the second cavity portion of the balloon.

[0012] A third aspect of the catheter of the present invention is the catheter of the first aspect, characterized in that a fourth gap is formed between the balloon and the inner shaft when the balloon is inflated.

[0013] In addition, a fourth aspect of the present invention is characterized in that, in the catheter of the second aspect, a fourth gap portion is formed between the balloon and the inner shaft when the balloon is inflated.

[0014] In addition, a fifth aspect of the present invention is characterized in that, in the catheter of the first aspect, the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip.

[0015] In addition, a sixth aspect of the present invention is characterized in that, in the catheter of the second aspect, the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip.

[0016] In addition, a seventh aspect of the present invention is characterized in that, in the catheter of the third aspect, the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip.

[0017] In addition, an eighth aspect of the present invention is a catheter according to the fourth aspect, characterized in that the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip.

[0018] A ninth aspect of the present invention is the catheter of the first aspect, characterized in that the base end of the wire is connected to the tip portion of the outer shaft.

[0019] A tenth aspect of the present invention is the catheter of the second aspect, wherein the base end of the wire is connected to the tip portion of the outer shaft.

[0020] An eleventh aspect of the present invention is the catheter of the third aspect, characterized in that the base end of the wire is connected to the tip portion of the outer shaft.

[0021] A twelfth aspect of the present invention is the catheter of the fourth aspect, characterized in that the base end of the wire is connected to the tip portion of the outer shaft.

[0022] A thirteenth aspect of the present invention is the catheter of the fifth aspect, characterized in that the base end of the wire is connected to the tip portion of the outer shaft.

[0023] Furthermore, a fourteenth aspect of the present invention is the catheter according to any one of the first to thirteenth aspects, wherein the wire is made of a superelastic alloy. [Effects of the Invention]

[0024] According to the first aspect of the catheter of the present invention, there is provided a hollow outer shaft having a first cavity, an inner shaft movably inserted into the first cavity of the outer shaft and extending from the tip of the outer shaft toward the tip, an expandable balloon having a second cavity, a tip connected to the tip of the inner shaft and a base connected to the outer shaft, and wound around the outer periphery of the inner shaft from the tip to the tip side of the outer shaft, and a wire inserted into the second cavity of the balloon.Therefore, by moving the inner shaft relative to the outer shaft, the balloon wound around the inner shaft and with the wire inserted therein can be easily expanded, thereby reducing the effect on blood flow and improving the expansion force on the blood vessel wall.

[0025] Furthermore, according to the second aspect of the present invention, in the catheter of the first aspect, the outer shaft is provided with a third void portion that communicates with the second void portion of the balloon, so that in addition to the effects of the catheter of the first aspect, the inner shaft can be moved smoothly relative to the outer shaft without being affected by the balloon.

[0026] Furthermore, according to the third aspect of the present invention, in the catheter of the first aspect, when the balloon is inflated, a fourth gap portion is formed between the balloon and the inner shaft, so that in addition to the effects of the catheter of the first aspect, the influence on blood flow can be further reduced and the expansion force on the vascular wall can be further improved.

[0027] Furthermore, according to the fourth aspect of the present invention, when the balloon is inflated in the catheter of the second aspect, a fourth gap portion is formed between the balloon and the inner shaft, so that in addition to the effects of the catheter of the second aspect, the influence on blood flow can be further reduced and the expansion force on the vascular wall can be further improved.

[0028] Furthermore, according to the fifth aspect of the present invention, in the catheter of the first aspect, the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip, so that in addition to the effects of the catheter of the first aspect, the catheter of the present invention itself can be easily manufactured.

[0029] Furthermore, according to the sixth aspect of the present invention, in the catheter of the second aspect, the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip, so that in addition to the effects of the catheter of the second aspect, the catheter of the present invention itself can be easily manufactured.

[0030] Furthermore, according to the seventh aspect of the present invention, in the catheter of the third aspect, the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip, so that in addition to the effects of the catheter of the third aspect, the catheter of the present invention itself can be easily manufactured.

[0031] Furthermore, according to the eighth aspect of the present invention, in the catheter of the fourth aspect, the wire is wound spirally around the outer periphery of the inner shaft from the tip of the outer shaft toward the tip, so that in addition to the effects of the catheter of the fourth aspect, the catheter of the present invention itself can be easily manufactured.

[0032] Furthermore, according to the ninth aspect of the present invention, in the catheter of the first aspect, the base end of the wire is connected to the tip portion of the outer shaft, so that in addition to the effects of the catheter of the first aspect, the length of the wire can be saved, thereby reducing manufacturing costs.

[0033] Furthermore, according to the tenth aspect of the present invention, in the catheter of the second aspect, the base end of the wire is connected to the tip portion of the outer shaft, so that in addition to the effects of the catheter of the second aspect, the length of the wire can be saved, thereby reducing manufacturing costs.

[0034] Furthermore, according to the 11th aspect of the present invention, in the catheter of the third aspect, the base end of the wire is connected to the tip portion of the outer shaft, so that in addition to the effects of the catheter of the third aspect, the length of the wire can be saved and manufacturing costs can be reduced.

[0035] Furthermore, according to the 12th aspect of the present invention, in the catheter of the fourth aspect, the base end of the wire is connected to the tip portion of the outer shaft, so that in addition to the effects of the catheter of the fourth aspect, the length of the wire can be saved and manufacturing costs can be reduced.

[0036] Furthermore, according to the thirteenth aspect of the present invention, in the catheter of the fifth aspect, the base end of the wire is connected to the tip portion of the outer shaft, so that in addition to the effects of the catheter of the fifth aspect, the length of the wire can be saved and manufacturing costs can be reduced.

[0037] Furthermore, according to the 14th aspect of the present invention, in the catheter of any one of the first to 13th aspects, the wire is made of a superelastic alloy, so in addition to the effects of the catheter of any one of the first to 13th aspects, the balloon can be expanded more easily, the effect on blood flow can be further reduced, and the expansion force on the vascular wall can be further improved. [Brief explanation of the drawings]

[0038] [Figure 1] 1 is an overall view of a catheter according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged longitudinal cross-sectional view of the catheter of the first embodiment. [Figure 3] FIG. 2 is an overall view of the catheter of the first embodiment when the balloon is expanded in diameter. [Figure 4] FIG. 2 is an enlarged longitudinal cross-sectional view of the catheter of the first embodiment when the balloon is expanded in diameter. [Figure 5] FIG. 2 is an overall view of the catheter of the first embodiment when the balloon is expanded in diameter and inflated. [Figure 6] FIG. 2 is an enlarged longitudinal cross-sectional view of the catheter of the first embodiment when the balloon is expanded in diameter and inflated. [Figure 7] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 8] 5 is a cross-sectional view of FIG. 4 taken along line B-B. [Figure 9] 7 is a cross-sectional view taken along CC in FIG. 6. [Figure 10] FIG. 10 is an enlarged longitudinal sectional view of a catheter according to a second embodiment. [Figure 11] FIG. 10 is an enlarged longitudinal sectional view of a catheter according to a third embodiment. [Figure 12]FIG. 10 is an enlarged longitudinal cross-sectional view of the catheter of the third embodiment when the balloon is expanded in diameter and inflated. [Figure 13] FIG. 10 is an overall view of the catheter of the fourth embodiment when the balloon is expanded in diameter. [Figure 14] FIG. 10 is an enlarged view of the catheter of the fourth embodiment when the balloon is expanded in diameter. DETAILED DESCRIPTION OF THE INVENTION

[0039] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0040] (First embodiment) First, a first embodiment of the present invention will be described. Note that the drawings used in this embodiment are exaggerated to facilitate understanding, and the dimensions are different from the actual dimensions.

[0041] Furthermore, in this embodiment and the embodiments described below, for convenience of explanation, the longitudinal direction of the catheter is referred to as the +X·-X direction, the +X·-X direction is referred to as the longitudinal direction, the +X direction is referred to as the base end side, and the -X direction is referred to as the tip side.

[0042] FIG. 1 is an overall view of a catheter according to a first embodiment of the present invention, FIG. 2 is an enlarged longitudinal cross-sectional view of the catheter, FIG. 3 is an overall view of the catheter according to the first embodiment when the balloon is expanded in diameter, and FIG. 4 is an enlarged longitudinal cross-sectional view of the catheter.

[0043] 5 is an overall view of the catheter of the first embodiment when the balloon is expanded and inflated, FIG. 6 is an enlarged longitudinal cross-sectional view thereof, FIG. 7 is a cross-sectional view taken along line AA in FIG. 2, FIG. 8 is a cross-sectional view taken along line BB in FIG. 4, and FIG. 9 is a cross-sectional view taken along line CC in FIG. 6.

[0044] As shown in Figures 1 to 9, the catheter 1 of this embodiment comprises a long, hollow outer shaft 9, an inner shaft 7 inserted into the outer shaft 9 so as to be movable longitudinally and extending from the tip of the outer shaft 9 toward the tip, and a balloon 3 wound around the outer periphery of the inner shaft 7 from the tip of the outer shaft 9 toward the tip.

[0045] The outer shaft 9 is long and has a hollow, approximately circular shape when viewed in cross section, and comprises an outer shaft main body 9a having a first, approximately cylindrical void portion 9g extending longitudinally therein, an outer shaft base end portion 9b connected to the base end of the outer shaft main body 9a, and an outer shaft auxiliary portion 9c formed adjacent to and parallel to the outer shaft 9a and having a third, approximately cylindrical void portion 9cg extending longitudinally therein.

[0046] The outer shaft 9 also has a cavity 8g at its base end 9b, which is in communication with the third cavity 9cg, and is provided with a connector 8 for connecting a syringe or the like from the outside.

[0047] The material for forming the outer shaft 9 is not particularly limited as long as it is made of a flexible material and is biocompatible. For example, polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc., resin materials such as soft polyvinyl chloride, polyurethane elastomer, polyamide elastomer, polyester elastomer, polyamide, crystalline polyethylene, crystalline polypropylene, etc., and various rubber materials such as silicone rubber and latex rubber can be used, and in this embodiment, polyamide elastomer is used.

[0048] The inner shaft 7 is long and has a hollow, approximately circular shape when viewed in cross section, and is inserted into the first gap 9g of the outer shaft 9 so as to be movable longitudinally, extending from the tip side of the tip of the outer shaft 9 to the base side of the base end of the outer shaft 9.

[0049] The inner shaft 7 also includes an inner shaft main body 7b having an approximately cylindrical void portion 7g therein that extends longitudinally to allow a medical instrument such as a guide wire to be inserted therethrough, a distal tip 7a connected to the distal end of the inner shaft main body 7b and having a void portion that communicates with the void portion 7g, and an inner shaft proximal end portion 7c connected to the proximal end of the inner shaft main body 7b and having a void portion that communicates with the void portion 7g.

[0050] The material for forming the inner shaft 7 is not particularly limited as long as it is a flexible material and is biocompatible, but the same material as the material for forming the outer shaft 9 described above can be used, and in this embodiment, polyamide elastomer is used.

[0051] The balloon 3 is long and has a hollow, approximately circular shape when viewed in cross section, with its tip connected to the tip portion of the inner shaft 7, and its base end wound counterclockwise around the outer circumference of the inner shaft 7 toward the base end, inserted into the third gap portion 9cg of the outer shaft auxiliary portion 9c, and its base end connected to the base end of the outer shaft auxiliary portion 9c.

[0052] The balloon 3 of this embodiment is not fixed at any position other than the distal end and the proximal end, but is fixed to the outer shaft auxiliary part 9c at least at the distal end of the outer shaft auxiliary part 9c.

[0053] The balloon 3 can be expanded or contracted using a syringe or the like connected to the connector 8, has a second hollow portion 3g, and is equipped with a long, hollow, and approximately circular balloon body 3a in cross section, a balloon base end portion 3b connected to the base end of the outer shaft auxiliary portion 9c within a third gap portion 9cg of the outer shaft auxiliary portion 9c, and a wire 5 inserted into the second gap portion 3g.

[0054] The wire 5 has an approximately circular cross-section, and its tip 5a is connected to the tip of the inner shaft 7, passes through the third gap 9cg of the outer shaft auxiliary part 9c and the second gap 3g of the balloon 3, and its base end 5b is connected to the tip of the connector 8.

[0055] The material from which the balloon 3 is made is not particularly limited as long as it is biocompatible and has a certain degree of flexibility. For example, resin materials such as polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymer, polyesters such as polyethylene terephthalate, polyvinyl chloride, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer, polyurethane, polyamide, polyamide elastomer, silicone rubber, and latex rubber can be used, and in this embodiment, polyamide elastomer is used.

[0056] Furthermore, the material for forming the wire 5 is not particularly limited as long as it is a biocompatible material and has spring properties, but for example, tungsten, Ni-Ti alloy, cobalt chromium alloy, stainless steel, etc. can be used, and in this embodiment, a Ni-Ti alloy, which is a superelastic alloy, is used.

[0057] Next, a method of using the catheter 1 described above will be described.

[0058] The catheter 1 of this embodiment is used to expand a narrowed portion of a body lumen such as a blood vessel, and as will be described later, it is capable of performing two-stage expansion on the narrowed portion, thereby improving the expansion effect on the narrowed portion.

[0059] When using the catheter 1, first, the inner shaft base end 7c of the inner shaft 7 is abutted against the outer shaft base end 9b of the outer shaft 9, and the guide wire is inserted from the inner shaft base end 7c into the gap 7g, and then protruded from the tip of the distal tip 7a, and the distal end of the catheter 1 is guided by the guide wire to reach the narrowed area in the patient.

[0060] In this embodiment, the state in which the inner shaft base end 7c of the inner shaft 7 is abutted against the outer shaft base end 9b of the outer shaft 9 means the state shown in Figure 1, and in this state, the stress that the wire 5 itself has, which tends to expand radially in the catheter 1, is suppressed by causing the inner shaft 7 to protrude from the tip of the outer shaft 9.

[0061] Therefore, a force is always acting on the wire 5 to expand in the radial direction of the catheter 1, and as a result, a force is always acting on the balloon 3 to expand in the radial direction of the catheter 1.

[0062] Furthermore, when the tip of the catheter 1 reaches the narrowed area of ​​the patient, the balloon 3 is not yet inflated, and as shown in Figure 7, in cross section, it covers the wire 5 with a small second gap 3g sandwiched around the outer periphery of the wire 5.

[0063] Then, after the distal end of the catheter 1 reaches the stricture in the patient, the inner shaft 7 is pulled toward the proximal end relative to the outer shaft 9. As shown in Figures 3 and 4, the balloon 3 wound around the outer periphery of the inner shaft 7 expands in the radial direction of the inner shaft 7, forming a fourth gap 2g1 between the balloon 3 and the inner shaft 7. At this point, the radius of the expanded balloon 3 from the center of the catheter 1 is R1.

[0064] In this embodiment, when the balloon 3 expands, the wire 5 itself does not come into direct contact with the narrowed area, but rather the tubular balloon 3, which is approximately circular in cross section and contains the wire 5, comes into direct contact with the narrowed area.Therefore, the balloon 3 can efficiently expand the narrowed area from its surface without penetrating into the inside of the narrowed area.

[0065] Furthermore, the balloon 3 is not yet inflated when expanded radially along the inner shaft 7, and as shown in Figure 8, in cross-sectional view, it covers the wire 5 with a small second gap 3g sandwiched around the outer periphery of the wire 5.

[0066] In this way, even when the balloon 3 is not inflated, the catheter 1 of this embodiment can expand a narrowed portion of a body lumen such as a blood vessel by expanding the balloon 3 to a radius R1. At this time, the balloon 3 of this embodiment has the wire 5 in the second cavity 3g, which improves the expansion force against the wall of a body lumen such as a blood vessel wall.

[0067] In addition, by expanding the balloon 3 to a radius R1, the first stage of expansion of the catheter 1 of this embodiment is completed, and if the first stage of expansion is sufficient to expand the narrowed area, the procedure ends here.

[0068] However, in the catheter 1 of this embodiment, if it is determined that the first stage of expansion is not sufficient to expand the stenotic area, a second stage of expansion can be performed as described above.

[0069] In this case, the operator of catheter 1 next connects injector 4, which is composed of syringe 4a with cavity 4g and plunger 4b, to connector 8, and injects the filling liquid in the direction F in Figure 5 to inflate balloon 3 as shown in Figures 5 and 6. Note that the radius from the center of catheter 1 when balloon 3 is inflated is R2, which is larger than R1.

[0070] Furthermore, the balloon 3 becomes slightly thinner as it expands, and as shown in FIG. 9, in cross section, it covers the wire 5 with a thick second void portion 3g sandwiched around the wire 5.

[0071] The narrowed portion of the body lumen, such as a blood vessel, can be further expanded by inflating the balloon 3. In this case, as described above, the balloon 3 of this embodiment includes the wire 5 in the second cavity 3g, and therefore the expansion force on the wall of the body lumen, such as the wall of a blood vessel, can be improved.

[0072] The catheter 1 of this embodiment comprises a hollow outer shaft 9 having a first gap 9g, an inner shaft 7 that is movably inserted into the first gap 9g of the outer shaft 9 and extends from the tip of the outer shaft 9 toward the tip, an expandable balloon 3 that has a second gap 3g, a tip connected to the tip of the inner shaft 7, a base end connected to the outer shaft 9, and is wound around the outer periphery of the inner shaft 7 from the tip to the tip side of the outer shaft 9, and a wire 5 inserted into the second gap 3g of the balloon 3. Therefore, by moving the inner shaft 7 relative to the outer shaft 9, the balloon 3 that is wound around the outer periphery of the inner shaft 7 and has the wire 5 inserted therein can be easily expanded, thereby reducing the effect on blood flow and improving the expansion force on the blood vessel wall.

[0073] Furthermore, according to the catheter 1 of this embodiment, when the balloon 3 is inflated, a fourth gap portion 2g1 is formed between the balloon 3 and the inner shaft 3, thereby further reducing the effect on blood flow and further improving the expansion force on the vascular wall.

[0074] Furthermore, according to the catheter 1 of this embodiment, the wire 5 is spirally wound around the outer periphery of the inner shaft 7 from the tip of the outer shaft 9 toward the tip, so that the catheter 1 itself can be easily manufactured.

[0075] Furthermore, according to the catheter 1 of this embodiment, the wire 5 is made of a superelastic alloy, which makes it easier to expand the balloon 3, further reducing the impact on blood flow and further improving the expansion force on the vascular wall.

[0076] (Second embodiment) Next, a second embodiment of the present invention will be described. Note that the drawings used in this embodiment are also exaggerated to facilitate understanding, and the dimensions are different from the actual dimensions.

[0077] A second embodiment of the present invention will be described below, but parts common to the first embodiment will be given the same reference numerals and descriptions thereof will be omitted.

[0078] The catheter 10 of this embodiment differs from the catheter 1 of the first embodiment in the longitudinal length of the balloon and the role of the outer shaft auxiliary part 9c. That is, in the catheter 1 of the first embodiment, the distal end of the balloon 3 is connected to the distal end of the inner shaft 7 and the proximal end is connected to the proximal end of the outer shaft auxiliary part 9c, but in the catheter 10 of this embodiment, the distal end of the balloon is connected to the distal end of the inner shaft 7 and the proximal end is connected to the distal end of the outer shaft auxiliary part 9c.

[0079] Furthermore, in the catheter 1 of the first embodiment, the third gap 9cg of the outer shaft auxiliary part 9c was a gap for inserting the balloon 3, but in the catheter 10 of this embodiment, the third gap 19cg of the outer shaft auxiliary part 19c is connected to the second gap 13g of the balloon 13.

[0080] FIG. 10 is an enlarged longitudinal sectional view of the catheter of the second embodiment.

[0081] As shown in Figure 10, the catheter 10 of this embodiment comprises a hollow outer shaft 19, an inner shaft 7 inserted into the outer shaft 19 so as to be movable longitudinally and extending from the tip of the outer shaft 19 toward the tip, and a balloon 13 wound around the outer circumference of the inner shaft 7 from the tip of the outer shaft 19 toward the tip.

[0082] The outer shaft 19 is long and has a hollow, approximately circular shape when viewed in cross section, and comprises an outer shaft main body 19a having a first, approximately cylindrical void portion 19g extending longitudinally therein, an outer shaft base end portion 19b connected to the base end of the outer shaft main body 19a, an outer shaft auxiliary portion 19c formed adjacent to and parallel to the outer shaft 19a and having a third, approximately cylindrical void portion 19cg extending longitudinally therein, and an outer shaft auxiliary base end portion 19d of the outer shaft auxiliary portion 19c connected to the tip of the connector 8.

[0083] In addition, the outer shaft 19 has a cavity 8g at the position of the outer shaft base end 19b, whose tip is connected to the outer shaft auxiliary base end 19d and which communicates with the third cavity 19cg, and is equipped with a connector 8 for connecting a syringe or the like from the outside.

[0084] In addition, the third gap 19cg of the outer shaft auxiliary part 19c is connected to the second gap 13g of the balloon 13 described later, and the outer shaft auxiliary part 19c receives the filling liquid injected from a syringe or the like connected to the connector 8, and then flows out into the second gap 13g of the balloon 13, thereby inflating the balloon 13.

[0085] The outer shaft 19 can be made of the same material as the outer shaft 9 of the first embodiment, and in this embodiment, polyamide elastomer is used.

[0086] The balloon 13 is long and has a hollow, approximately circular shape when viewed in cross section, with its tip connected to the tip portion of the inner shaft 7, and its base end wound counterclockwise around the outer circumference of the inner shaft 7 toward the base end, and connected to the tip of the outer shaft auxiliary part 19c.

[0087] The balloon 13 can be expanded or contracted using a syringe or the like connected to the connector 8, has a second gap 13g, and comprises a long, hollow, and approximately circular balloon body 13a in cross section, a balloon base end 13b connected to the tip of the outer shaft auxiliary part 19c, and a wire 5 inserted into the second gap 13g.

[0088] In this embodiment, the wire 5 has its tip 5a connected to the tip portion of the inner shaft 7, passes through the third gap 19cg of the outer shaft auxiliary portion 19c and the second gap 13g of the balloon 13, and its base end 5b connected to the tip portion of the connector 8.

[0089] The material for forming the balloon 13 can be the same as that for the balloon 3 of the first embodiment, and in this embodiment, polyamide elastomer is used.

[0090] The method of using the catheter 10 described above is the same as that of the catheter 1 of the first embodiment, and like the catheter 1 of the first embodiment, the catheter 10 can perform two-stage dilation of the stenotic area, thereby improving the dilation effect of the stenotic area.

[0091] In particular, when performing the second stage of expansion using catheter 10, the operator of catheter 10 connects injector 4, which consists of syringe 4a with gap 4g and plunger 4b, to connector 8, and injects filling liquid in direction F as shown in Figure 5 to inflate balloon 13. At this time, the filling liquid flows from injector 4 through gap 8g of connector 8 and third gap 19cg of outer shaft auxiliary part 19c, into second gap 13g of balloon 13, and inflates balloon 13.

[0092] The narrowed portion of the body lumen, such as a blood vessel, can be further expanded by inflating the balloon 13. In this case, as described above, the balloon 13 of this embodiment includes the wire 5 in the second cavity 13g, and therefore the expansion force on the wall of the body lumen, such as the wall of a blood vessel, can be improved.

[0093] The catheter 10 of this embodiment comprises a hollow outer shaft 19 having a first cavity 19g, an inner shaft 7 that is movably inserted into the first cavity 19g of the outer shaft 19 and extends from the tip of the outer shaft 19 toward the tip, an expandable balloon 13 that has a second cavity 13g, a tip connected to the tip of the inner shaft 7, a base end connected to the outer shaft 19, and is wound around the outer periphery of the inner shaft 7 from the tip to the tip side of the outer shaft 19, and a wire 5 inserted into the second cavity 13g of the balloon 13. Therefore, by moving the inner shaft 7 relative to the outer shaft 19, the balloon 13 that is wound around the outer periphery of the inner shaft 7 and has the wire 5 inserted therein can be easily expanded, thereby reducing the effect on blood flow and improving the expansion force on the blood vessel wall.

[0094] Furthermore, according to the catheter 10 of this embodiment, the outer shaft 19 has a third void portion 19cg that communicates with the second void portion 13g of the balloon 13, so that the inner shaft 7 can be moved smoothly relative to the outer shaft 19 without being affected by the balloon 13.

[0095] Furthermore, according to the catheter 10 of this embodiment, when the balloon 13 is inflated, a fourth gap portion 2g1 is formed between the balloon 13 and the inner shaft 7, thereby further reducing the effect on blood flow and further improving the expansion force on the vascular wall.

[0096] Furthermore, according to the catheter 10 of this embodiment, the wire 5 is wound spirally around the outer periphery of the inner shaft 7 from the tip of the outer shaft 19 toward the tip, so that the catheter 10 itself can be manufactured easily.

[0097] Furthermore, according to the catheter 10 of this embodiment, the wire 5 is made of a superelastic alloy, which makes it possible to expand the balloon 13 even more easily, further reducing the impact on blood flow and further improving the expansion force on the vascular wall.

[0098] (Third embodiment) Next, a third embodiment of the present invention will be described. Note that the drawings used in this embodiment are also exaggerated to facilitate understanding, and the dimensions are different from the actual dimensions.

[0099] Further, a third embodiment of the present invention will be described below, but parts common to the first or second embodiment will be given the same reference numerals and description thereof will be omitted.

[0100] The catheter 20 of this embodiment differs from the catheter 10 of the second embodiment in the length of the wire in the longitudinal direction.

[0101] FIG. 11 is an enlarged longitudinal sectional view of the catheter of the third embodiment, and FIG. 12 is an enlarged longitudinal sectional view of the catheter of the third embodiment when the balloon is expanded in diameter and inflated.

[0102] As shown in Figures 11 and 12, the catheter 20 of this embodiment comprises a hollow outer shaft 19, an inner shaft 7 that is inserted into the outer shaft 19 so as to be movable longitudinally and extends from the tip of the outer shaft 19 toward the tip, and a balloon 13 that is wound around the outer circumference of the inner shaft 7 from the tip of the outer shaft 19 toward the tip.

[0103] The balloon 13 can be expanded or contracted using a syringe or the like connected to the connector 8, has a second gap portion 13g, and comprises a long, hollow, approximately circular balloon body 13a in cross section, a balloon base end portion 13b connected to the tip of the outer shaft auxiliary portion 19c, and a wire 25 inserted into the second gap portion 13g.

[0104] In the present embodiment, the wire 25 has a distal end 25a connected to the distal end of the inner shaft 7 and a proximal end 25b connected to the distal end of the outer shaft auxiliary part 19c.

[0105] The wire 25 can be made of the same material as the wire 5 of the first embodiment, and in this embodiment, a Ni-Ti alloy, which is a superelastic alloy, is used.

[0106] The method of using the catheter 20 described above is the same as that of the catheter 1 of the first embodiment, and like the catheter 1 of the first embodiment, the catheter 20 can perform two-stage expansion of the stenotic area, thereby improving the expansion effect of the stenotic area.

[0107] In particular, in catheter 20, the base end of wire 25 is connected to the tip of outer shaft auxiliary part 19c, and the length of wire 25 is short, which improves the flexibility of the entire catheter 20 and also increases the cross-sectional area of ​​third gap part 19cg of outer shaft auxiliary part 19c, thereby reducing the flow resistance of the filling liquid flowing in through connector 8 and making it easier for the filling liquid to flow into balloon 13.

[0108] Furthermore, after the distal end of catheter 20 has reached the stricture in the patient, when inner shaft 7 is pulled toward the proximal end relative to outer shaft 19 as the first stage of expansion, balloon 13 wound around the outer periphery of inner shaft 7 expands in the radial direction of inner shaft 7 as shown in Fig. 12, forming fourth gap 22g1 between balloon 13 and inner shaft 7. At this point, the radius from the center of catheter 1 when balloon 13 has expanded in diameter is R1, as shown in Fig. 4.

[0109] Then, in the second stage of expansion, the balloon 13 is inflated to further expand the narrowed portion of the body lumen, such as a blood vessel. As described above, the balloon 13 of this embodiment includes the wire 25 in the second cavity 13g, which improves the expansion force against the wall of the body lumen, such as the wall of the blood vessel. Furthermore, the radius from the center of the catheter 20 when the balloon 13 is inflated is R2, as shown in FIG. 6, which is larger than R1.

[0110] The catheter 20 of this embodiment comprises a hollow outer shaft 19 having a first gap 19g, an inner shaft 7 that is movably inserted into the first gap 19g of the outer shaft 19 and extends from the tip of the outer shaft 19 toward the tip, an expandable balloon 13 that has a second gap 13g, a tip connected to the tip of the inner shaft 7, a base end connected to the outer shaft 19, and is wound around the outer periphery of the inner shaft 7 from the tip to the tip side of the outer shaft 19, and a wire 25 inserted into the second gap 13g of the balloon 13. Therefore, by moving the inner shaft 7 relative to the outer shaft 19, the balloon 13 that is wound around the outer periphery of the inner shaft 7 and has the wire 25 inserted therein can be easily expanded, thereby reducing the effect on blood flow and improving the expansion force on the blood vessel wall.

[0111] Furthermore, according to the catheter 20 of this embodiment, the outer shaft 19 has a third void portion 19cg that communicates with the second void portion 13g of the balloon 13, so that the inner shaft 7 can be moved smoothly relative to the outer shaft 19 without being affected by the balloon 13.

[0112] Furthermore, according to the catheter 20 of this embodiment, when the balloon 13 is inflated, a fourth gap portion 22g1 is formed between the balloon 13 and the inner shaft 7, thereby further reducing the effect on blood flow and further improving the expansion force on the vascular wall.

[0113] Furthermore, according to the catheter 20 of this embodiment, the wire 25 is spirally wound around the outer periphery of the inner shaft 7 from the tip of the outer shaft 19 toward the tip, so that the catheter 20 itself can be easily manufactured.

[0114] Furthermore, according to the catheter 20 of this embodiment, the base end of the wire 25 is connected to the distal end of the outer shaft 19, so that the length of the wire 25 can be saved and manufacturing costs can be reduced.

[0115] Furthermore, according to the catheter 20 of this embodiment, the wire 25 is made of a superelastic alloy, which makes it possible to expand the balloon 13 even more easily, further reducing the effect on blood flow and further improving the expansion force on the vascular wall.

[0116] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described. The drawings used in this embodiment are also exaggerated to facilitate understanding, and the dimensions are different from the actual dimensions.

[0117] Further, a fourth embodiment of the present invention will be described below, but parts common to the first to third embodiments will be given the same reference numerals and description thereof will be omitted.

[0118] The catheter 30 of this embodiment differs from the catheter 20 of the third embodiment in the shapes of the outer shaft and the inner shaft. That is, the catheter 20 of the third embodiment has a configuration in which the inner shaft 7 is pulled straight toward the base end relative to the outer shaft 19, but the catheter 30 of this embodiment has a configuration in which the outer shaft 39 is rotated counterclockwise relative to the inner shaft 37 toward the tip and pushed.

[0119] Fig. 13 is an overall view of the catheter of the fourth embodiment when the balloon is expanded in diameter, and Fig. 14 is an enlarged view of the catheter of the fourth embodiment when the balloon is expanded in diameter. For convenience of explanation, Fig. 14 shows a longitudinal cross section of only the balloon 13 and the outer shaft auxiliary portion 19c.

[0120] As shown in Figures 13 and 14, the catheter 30 of this embodiment comprises a hollow outer shaft 39, an inner shaft 37 inserted into the outer shaft 39 so as to be movable longitudinally and extending from the tip of the outer shaft 39 toward the tip, and a balloon 13 wound around the outer periphery of the inner shaft 37 from the tip of the outer shaft 39 toward the tip.

[0121] The outer shaft 39 is long and has a hollow, approximately circular shape when viewed in cross section, and comprises an outer shaft main body 39a having a first void portion 39g of approximately cylindrical shape extending longitudinally therein (not shown, but similar to the first void portion 19g of the third embodiment), an outer shaft base end portion 39b connected to the base end of the outer shaft main body 39a, an outer shaft auxiliary portion 39c formed adjacent to and parallel to the outer shaft 39a and having a third void portion 39cg of approximately cylindrical shape extending longitudinally therein, and a convex portion 39d (not shown, but shaped so as to be able to move within the groove portion 37d described later) formed on the outer shaft base end portion 39b on the inner circumference of the outer shaft 39.

[0122] Furthermore, the outer shaft 39 has a cavity 8g at the outer shaft base end 39b, which is in communication with the third cavity 39cg, and is provided with a connector 8 for connecting a syringe or the like from the outside.

[0123] In addition, the third gap 39cg of the outer shaft auxiliary part 39c is connected to the second gap 13g of the balloon 13, and the outer shaft auxiliary part 39c receives the filling liquid injected from a syringe or the like connected to the connector 8, and then flows out into the second gap 13g of the balloon 13, thereby inflating the balloon 13.

[0124] The outer shaft 39 can be made of the same material as the outer shaft 9 of the first embodiment, and in this embodiment, polyamide elastomer is used.

[0125] The inner shaft 37 is long and has a hollow, approximately circular shape when viewed in cross section, and is inserted into the first gap portion 39g of the outer shaft 39 so as to be movable longitudinally, extending from the tip side of the tip of the outer shaft 39 to the base side of the base end of the outer shaft 39.

[0126] The inner shaft 37 also includes an inner shaft main body 37b having an internal, approximately cylindrical void 37g (not shown, but similar to the void 7g of the third embodiment) extending longitudinally to allow a medical instrument such as a guide wire to be inserted therethrough, a distal tip 37a connected to the distal end of the inner shaft main body 37b and having a void communicating with the void 37g, an inner shaft base end 37c connected to the proximal end of the inner shaft main body 37b and having a void communicating with the void 37g, and a groove 37d formed on the outer periphery of the inner shaft 37, extending from the inner shaft base end 37c toward the distal end and spiraling counterclockwise toward the distal end.

[0127] The material for forming the inner shaft 37 can be the same as that for the inner shaft 7 of the first embodiment, and in this embodiment, polyamide elastomer is used.

[0128] The balloon 13 can be expanded or contracted using a syringe or the like connected to the connector 8, has a second hollow portion 13g, and comprises a long, hollow, approximately circular balloon body 13a in cross section, a balloon base end portion 13b connected to the tip of the outer shaft auxiliary portion 19c, and a wire 25 inserted into the second hollow portion 13g.

[0129] Next, a method of using the catheter 30 described above will be described.

[0130] The catheter 30 of this embodiment, like the catheter 1 of the first embodiment, the catheter 10 of the second embodiment, and the catheter 20 of the third embodiment described above, is designed to dilate a narrowed portion of a body lumen such as a blood vessel, and is capable of performing two-stage dilation of the narrowed portion, thereby improving the dilation effect of the narrowed portion.

[0131] When using the catheter 30, first, the inner shaft base end 37c of the inner shaft 37 is abutted against the outer shaft base end 39b of the outer shaft 39, and the guide wire is inserted from the inner shaft base end 37c into the gap 37g, and then protruded from the tip of the distal tip 37a, and the distal end of the catheter 30 is guided by the guide wire to reach the narrowed area in the patient.

[0132] In this embodiment, too, the state in which the inner shaft base end 37c of the inner shaft 37 is abutted against the outer shaft base end 39b of the outer shaft 39 means that the stress that the wire 25 itself has, which tends to expand radially in the catheter 30, is suppressed by causing the inner shaft 37 to protrude from the tip of the outer shaft 39.

[0133] Therefore, a force is always acting on the wire 25 to expand in the radial direction of the catheter 30, and as a result, a force is always acting on the balloon 13 to expand in the radial direction of the catheter 30.

[0134] Then, after the distal end of the catheter 30 has reached the stenotic area in the patient, when the outer shaft 39 is pushed toward the distal end relative to the inner shaft 37, the outer shaft 39 rotates 90 degrees in the +θ direction (counterclockwise as viewed toward the distal end) relative to the inner shaft 37, as shown in Figures 13 and 14, and the balloon 13 wound around the outer periphery of the inner shaft 37 expands in diameter in the radial direction of the inner shaft 37, forming a fourth gap 32g1 between the balloon 13 and the inner shaft 37. At this point, the radius from the center of the catheter 30 when the balloon 13 has expanded in diameter is R3, which is larger than R1 in Figure 4 of the first embodiment.

[0135] The radius of the balloon 13 from the center of the catheter 30 is R3, which is larger than R1, because the winding direction of the wire 25 is counterclockwise toward the tip, and therefore, by rotating the outer shaft auxiliary part 39c counterclockwise toward the tip, the winding of the wire 25 is loosened.

[0136] In this way, even when the balloon 13 is not inflated, the catheter 20 of this embodiment can expand the narrowed portion of a body lumen such as a blood vessel by expanding the balloon 13 to a radius R3 that is larger than the radius R1. At this time, the balloon 13 of this embodiment has the wire 25 in the second cavity 13g, which improves the expansion force against the wall of a body lumen such as a blood vessel wall.

[0137] In addition, by expanding the balloon 13 to a radius R3, the first stage of expansion of the catheter 30 of this embodiment is completed, and if the first stage of expansion is sufficient to expand the narrowed area, the procedure ends here.

[0138] However, even in the catheter 30 of this embodiment, if it is determined that the first stage of expansion does not sufficiently expand the stenotic area, the second stage of expansion can be performed as described above.

[0139] In this case, the operator of catheter 30 next connects injector 4, which is composed of syringe 4a with cavity 4g and plunger 4b, to connector 8, and injects the filling liquid in the direction F as in Figure 5, thereby inflating balloon 13. Note that the radius from the center of catheter 30 when balloon 13 is inflated becomes larger than R2.

[0140] The narrowed portion of the body lumen, such as a blood vessel, can be further expanded by inflating the balloon 13. In this case, as described above, the balloon 13 of this embodiment includes the wire 25 in the second cavity 13g, and therefore, the expansion force on the wall of the body lumen, such as the wall of a blood vessel, can be improved.

[0141] In the catheter 30 of this embodiment, a spiral groove 37d is provided on the outer periphery of the inner shaft 37, and a convex portion 39d is provided on the inner periphery of the outer shaft 39, but it is also possible to provide a spiral convex portion on the outer periphery of the inner shaft 37, and a concave portion on the inner periphery of the outer shaft 39.

[0142] Furthermore, in the catheter 30 of this embodiment, the rotation angle of the outer shaft 39 relative to the inner shaft 37 is described as 90 degrees, but this angle is arbitrary, and the rotation angle may be any number of degrees within the range in which the wire expands in diameter.

[0143] Furthermore, in the catheter 30 of this embodiment, the wire 25 is wound counterclockwise toward the tip, and the outer shaft 39 is rotated counterclockwise toward the tip relative to the inner shaft 37 and pushed, but the rotation direction of the outer shaft relative to the inner shaft needs to be aligned with the winding direction of the wire.

[0144] For example, if the wire is wound counterclockwise toward the tip, the mechanism can rotate the outer shaft counterclockwise relative to the inner shaft toward the tip, and if the wire is wound clockwise toward the tip, the mechanism can rotate the outer shaft clockwise relative to the inner shaft toward the tip.

[0145] Furthermore, in the catheter 30 of this embodiment, the outer shaft 39 is rotated and pushed relative to the inner shaft 37, but the inner shaft may be pulled toward the proximal end relative to the outer shaft.

[0146] For example, if the wire is wound counterclockwise toward the tip, the mechanism can be configured to rotate the inner shaft clockwise toward the tip relative to the outer shaft and pull it toward the base end, and if the wire is wound clockwise toward the tip, the mechanism can be configured to rotate the inner shaft counterclockwise toward the tip relative to the outer shaft and pull it toward the base end.

[0147] That is, the outer shaft may be rotated in the direction that loosens the winding of the wire and pushed toward the distal end, or the inner shaft may be rotated in the direction that loosens the winding of the wire and pulled toward the proximal end.

[0148] The catheter 30 of this embodiment comprises a hollow outer shaft 39 having a first cavity 39g, an inner shaft 37 movably inserted into the first cavity 39g of the outer shaft 39 and extending from the tip of the outer shaft 39 toward the tip, an expandable balloon 13 having a second cavity 13g, a tip connected to the tip of the inner shaft 37, a base end connected to the outer shaft 39, and wound around the outer periphery of the inner shaft 37 from the tip to the tip side of the outer shaft 39, and a wire 25 inserted into the second cavity 13g of the balloon 13. Therefore, by moving the inner shaft 37 relative to the outer shaft 39, the balloon 13 wound around the outer periphery of the inner shaft 37 and with the wire 25 inserted therein can be easily expanded, thereby reducing the effect on blood flow and improving the expansion force on the blood vessel wall.

[0149] Furthermore, according to the catheter 30 of this embodiment, the outer shaft 39 has a third void portion 39cg that communicates with the second void portion 13g of the balloon 13, so that the inner shaft 37 can be moved smoothly relative to the outer shaft 39 without being affected by the balloon 13.

[0150] Furthermore, according to the catheter 30 of this embodiment, when the balloon 13 is inflated, a fourth gap portion 32g1 is formed between the balloon 13 and the inner shaft 37, thereby further reducing the effect on blood flow and further improving the expansion force on the vascular wall.

[0151] Furthermore, according to the catheter 30 of this embodiment, the wire 25 is spirally wound around the outer periphery of the inner shaft 37 from the tip of the outer shaft 39 toward the tip, so that the catheter 30 itself can be easily manufactured.

[0152] Furthermore, according to the catheter 30 of this embodiment, the base end of the wire 25 is connected to the distal end of the outer shaft 39, so that the length of the wire 25 can be saved and manufacturing costs can be reduced.

[0153] Furthermore, according to the catheter 30 of this embodiment, the wire 25 is made of a superelastic alloy, which allows the balloon 13 to be expanded more easily, further reducing the effect on blood flow and further improving the expansion force on the vascular wall.

[0154] Furthermore, according to the catheter 30 of this embodiment, the outer shaft 39 can be rotated relative to the inner shaft 37 in a direction that loosens the winding of the wire 25, thereby allowing the balloon 13 to be further expanded, further reducing the impact on blood flow and further improving the expansion force on the vascular wall.

[0155] The above describes various embodiments of the catheter of the present invention, but the present invention is not limited to the above embodiments and can be implemented with various modifications within the scope of the gist of the present invention.

[0156] For example, the point of connecting the base end to the distal end of the outer shaft, such as the wire 25, can be applied to the catheter 1 of the first embodiment and the catheter 10 of the second embodiment. In this case, the length of the wire can be saved, thereby reducing manufacturing costs.

[0157] Furthermore, the mechanism for rotating the outer shaft relative to the inner shaft in the direction that loosens the winding of the wire can also be applied to the catheter 1 of the first embodiment, the catheter 10 of the second embodiment, and the catheter 20 of the third embodiment. In this case, the balloon can be further inflated, the effect on blood flow can be further reduced, and the inflation force on the blood vessel wall can be further improved. [Explanation of symbols]

[0158] 1, 10, 20, 30... catheter 2g1, 22g1, 32g1...Fourth gap 3,13···Balloon 3a, 13a... Balloon body 3b,13b... Balloon proximal end 3g, 13g...Second gap 4...Injector 4a···Syringe 4b Plunger 5,25...wire 5a, 25a... Wire tip 5b, 25b... Wire base end 7,37···Inner shaft 7a, 37a Tip 7b, 37b... Inner shaft body 7c, 37c... Base end of inner shaft 7g,8g...Void part 8···Connector 9,19,39···Outer shaft 9a, 19a, 39a... Outer shaft body 9b, 19b, 39b... Base end of outer shaft 9c, 19c, 39c... Outer shaft auxiliary part 9cg, 19cg, 39cg...Third gap 9g, 19g...First gap 37d...Groove

Claims

1. a hollow outer shaft having a first gap; an inner shaft that is movably inserted into the first gap portion of the outer shaft and extends from a tip end of the outer shaft toward a tip end thereof; an expandable balloon having a second gap, a distal end connected to the distal end of the inner shaft, a proximal end connected to the outer shaft, and wound around the outer periphery of the inner shaft from the distal end of the outer shaft toward the distal end; a wire inserted into the second cavity of the balloon; A catheter comprising:

2. 2. The catheter according to claim 1, wherein the outer shaft has a third cavity portion that communicates with the second cavity portion of the balloon.

3. 2. The catheter according to claim 1, wherein a fourth gap is formed between the balloon and the inner shaft when the balloon is inflated.

4. 3. The catheter according to claim 2, wherein a fourth gap is formed between the balloon and the inner shaft when the balloon is inflated.

5. 2. The catheter according to claim 1, wherein the wire is wound spirally around the outer periphery of the inner shaft from the distal end of the outer shaft to the distal end side.

6. 3. The catheter according to claim 2, wherein the wire is wound spirally around the outer periphery of the inner shaft from the distal end of the outer shaft to the distal end side.

7. 4. The catheter according to claim 3, wherein the wire is wound spirally around the outer periphery of the inner shaft from the distal end of the outer shaft to the distal end side.

8. 5. The catheter according to claim 4, wherein the wire is wound spirally around the outer periphery of the inner shaft from the distal end of the outer shaft to the distal end side.

9. The catheter according to claim 1 , wherein the proximal end of the wire is connected to the distal end of the outer shaft.

10. The catheter according to claim 2, wherein the proximal end of the wire is connected to the distal end of the outer shaft.

11. The catheter according to claim 3 , wherein the proximal end of the wire is connected to the distal end of the outer shaft.

12. The catheter according to claim 4, wherein the proximal end of the wire is connected to the distal end of the outer shaft.

13. The catheter according to claim 5, wherein the proximal end of the wire is connected to the distal end of the outer shaft.

14. 14. The catheter according to claim 1, wherein the wire is made of a superelastic alloy.

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