JP2012170472A - Catheter and therapeutic method for intravascular stenosis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter allowing the effective length of a shaft to be adjusted to an optional length if necessary, and a therapeutic method for an intravascular stenosis using the catheter.SOLUTION: The catheter 10 includes a flexible, hollow long-sized shaft 12; a hub 13 provided on the proximal end side rather than the shaft 12; an extensible mechanism 14 provided between the shaft 12 and the hub 13; and a fastening mechanism 16 provided on the outside of the extensible mechanism 14 and configured to be capable of fastening the extensible mechanism 14. The extensible mechanism 14 has first to third tubular members 22, 24, 26 of telescopic structure mutually slidable in an axial direction within a regulated range.

Description

  The present invention relates to a catheter whose effective length can be changed as necessary, and a method for treating a stenosis in a blood vessel using the catheter.

  2. Description of the Related Art Conventionally, it has been widely performed to introduce a catheter into a living organ such as a blood vessel to inspect and treat a lesioned part (for example, a stenosis) in the living organ. This type of catheter has a long shaft (catheter body), a hub connected to the proximal end portion of the shaft, and a kink protector (also referred to as strain relief) surrounding the proximal end portion of the shaft. (For example, refer to Patent Document 1 below).

  In the treatment of myocardial infarction and angina pectoris, a guiding catheter shaft is inserted into a blood vessel through an insertion tool called a sheath introducer, and the tip of the shaft is placed at a desired position of the living organ (for example, in the vicinity of the stenosis, It is arranged at the entrance of coronary artery, carotid artery, renal artery and the like.

US Pat. No. 6,068,622

  Conventional catheters have a constant length (effective shaft length) from the tip of the shaft to the kink protector. However, since there are individual differences in the shape (eg, meandering) or length of the blood vessel, the length of the blood vessel from the proximal end of the sheath introducer punctured to the living body to the desired position of the living organ is the effective length of the shaft. If shorter, the tip of the shaft cannot reach the desired position of the living organ. For example, in PTCA (percutaneous coronary angioplasty), it is necessary to avoid that the tip of the guiding catheter does not reach the coronary ostium or that it is disengaged at the time of use of the treatment device even if it is tightly engaged with the coronary ostium.

  It is conceivable to use a catheter with a longer effective shaft length. However, when such a catheter is used, the operability deteriorates and the remaining portion of the shaft (the proximal end of the sheath introducer and the kink protector) The shaft between them is likely to break or kink. In the case of a guiding catheter having a longer effective length, the length of the treatment catheter (for example, PTCA in the case of PTCA) inserted into the guiding catheter is insufficient, and the balloon is guided. There is a problem that it does not protrude from the distal end of the catheter, and it is necessary to prepare an extra long treatment catheter in advance.

  The present invention has been made in consideration of such problems, and a catheter capable of adjusting the effective length of a shaft to an arbitrary length as necessary, and treatment of a stenosis in a blood vessel using the catheter. It aims to provide a method.

  In order to achieve the above object, a catheter according to the present invention includes a flexible hollow long shaft, a hub provided on the proximal side of the shaft, and the shaft and the hub. A telescopic mechanism provided; and a tightening mechanism provided outside the telescopic mechanism and configured to be capable of tightening the telescopic mechanism, wherein the telescopic mechanisms slide in the axial direction relative to each other within a restricted range. It is characterized by having a plurality of nested tubular members.

  According to the present invention, the shaft and the hub are connected to each other by the telescopic mechanism having a plurality of nested tubular members. Therefore, the shaft can be effectively moved by moving the shaft in the axial direction relative to the hub. The length can be changed (stretched). Therefore, when the length of the shaft is insufficient, it is possible to reliably reach a desired position (for example, the coronary artery ostium) in the living organ by extending the effective length of the shaft. If the shaft is too long, shortening the effective length of the shaft can prevent the shaft from being bent or kinked from being exposed to the outside from the base end of the sheath introducer, and can be inserted into the catheter. The distal end of a treatment device (for example, a balloon catheter) to be used can be reliably projected from the distal end of the shaft. In addition, it is not necessary to prepare a plurality of catheters having different lengths, which is excellent in medical economics and does not require a catheter replacement operation, thereby reducing the burden on the patient. If the telescopic mechanism is tightened from the outside by adjusting the effective length of the shaft from the outside, the relative displacement between the tubular members is prevented, so that the effective length of the shaft can be suitably held at an arbitrary length, from the hub The torque transmission to the shaft can be improved, and the liquid tightness can be secured by sealing between the tubular members.

  Said catheter WHEREIN: The outer side recessed part or outer side convex part extended in an axial direction is provided in the outer peripheral part of tubular members other than what is located in the outermost side among these several tubular members, These several tubular members Among the inner peripheral portions of the tubular member other than the innermost one, an inner convex portion or an inner concave portion extending in the axial direction is provided, and the outer concave portion or the outer convex portion is the inner convex portion. Or it is good to engage with the said inner side recessed part.

  According to the above configuration, when the elastic member is tightened by the tightening mechanism, the tubular members are engaged with each other by the concavo-convex shape provided on the inner peripheral portion and the outer peripheral portion thereof, so that relative rotation is prevented. The torque transmission from the hub to the shaft can be further improved.

  In the above catheter, a rough surface is formed on each of the outer peripheral portions of the tubular members other than the outermost one of the plurality of tubular members and the inner peripheral portion of the tubular member other than the innermost one. It should be provided.

  According to the above configuration, when the expansion / contraction member is tightened by the tightening mechanism, the frictional resistance between the tubular members is increased by the rough surfaces provided on the inner peripheral portion and the outer peripheral portion of the tubular members. Torque transmission to the can be further improved.

  In the above catheter, each of the plurality of tubular members has a diameter-expanded portion and a proximal-end diameter-reduced portion that is provided on the proximal end side of the diameter-expanded portion and has a diameter reduced with respect to the diameter-expanded portion, Among the plurality of tubular members, the tubular members other than the outermost one are, when the tubular member is located on the most distal side within the movable range, the proximal end of the proximal end reduced diameter portion of the tubular member The position may extend to the vicinity of the proximal end position or the inside of the proximal end reduced diameter portion of another tubular member directly surrounding the tubular member.

  According to the above configuration, when the linear member is inserted from the proximal end side of the hub, the linear member can be prevented from entering between the enlarged diameter portion and the proximal reduced diameter portion, and thus the procedure can be quickly performed. Can be carried out.

  In the above-described catheter, the tightening mechanism is formed of a tubular elastic body surrounding the expansion / contraction mechanism, and has a tightening member whose inner diameter is reduced by being compressed in the axial direction, and a position in the axial direction with respect to the expansion / contraction mechanism. And a pressing member that presses the fastening member in the axial direction.

  According to the above configuration, since the expansion / contraction mechanism is tightened from the outside by the tightening member whose inner diameter is reduced by the movement of the pressing member in the axial direction, the inner peripheral surface and the outer peripheral surface of the tubular members can be securely adhered to each other. .

  In the catheter described above, the tightening mechanism can change a position in the axial direction with respect to the plurality of tightening members provided at intervals in the circumferential direction along the outer periphery of the telescopic mechanism, and the telescopic mechanism. It is good to have a tubular pressing member provided with a tapered inner surface that surrounds the telescopic mechanism and the plurality of fastening members and has a diameter reduced toward the tip.

  According to the above configuration, since the fastening member is displaced inward by the movement of the pressing member having the tapered inner peripheral surface in the axial direction, the expansion / contraction mechanism is tightened from the outside. The surface and the outer peripheral surface can be reliably adhered.

  The present invention also relates to a method for treating a stenosis in a blood vessel using a catheter, wherein the catheter is configured to reduce the effective length of a shaft relative to a hub, and the most distal portion of the catheter. A step of advancing the catheter and the balloon catheter into a blood vessel with the balloon catheter balloon disposed in a lumen at a near position; a step of positioning a distal end of the catheter within a stenosis; and the hub of the catheter Retracting the distal end of the catheter by reducing the effective length of the shaft relative to the hub without changing the position of the hub, and positioning the balloon of the balloon catheter within the stenosis. It is characterized by.

  According to the catheter of the present invention, the effective length of the shaft can be changed (adjusted) to an arbitrary length as necessary. Therefore, it is possible to reliably reach a desired position in the living organ (for example, the coronary artery mouth or the back side in the coronary artery), the shaft can be prevented from being bent or kinked, and the distal end of the treatment device can be reliably secured. Excellent effects such as being able to project from the shaft are obtained. Further, according to the method for treating a stenosis in a blood vessel according to the present invention, the operation of projecting the balloon from the tip of the catheter in the blood vessel and the operation of housing the balloon in the catheter can be performed easily and quickly. The stenosis can be quickly treated.

1 is a partially omitted side view of a catheter according to an embodiment of the present invention. FIG. 2A is a partially omitted cross-sectional view schematically showing a main part of the catheter shown in FIG. 1, FIG. 2A shows a state in which the expansion / contraction mechanism is not tightened by the tightening mechanism, and FIG. The mechanism is shown tightened. FIG. 3A is a partially omitted cross-sectional view schematically showing a main part of the catheter shown in FIG. 1, in which FIG. 3A shows a state in which the shaft is moved to the most distal side, and FIG. The state moved to is shown. 4A is a partially omitted sectional view of a catheter provided with a tightening mechanism according to a modification, and FIG. 4B is a sectional view taken along line IVB-IVB in FIG. 4A. 5A is a cross-sectional view of the expansion / contraction mechanism along the line VA-VA in FIG. 2A, FIG. 5B is a cross-sectional view of the expansion / contraction mechanism according to the first modification, and FIG. 5C is according to the second modification. It is sectional drawing of an expansion-contraction mechanism. 6A is a partially omitted cross-sectional view of a catheter provided with a telescopic mechanism according to a third modification, and FIG. 6B is a partially enlarged view of FIG. 6A. It is a schematic explanatory drawing which shows the introduction method to the blood vessel of a catheter. It is a schematic explanatory drawing which shows the 1st treatment method using the catheter of this invention. It is a schematic explanatory drawing which shows the 2nd treatment method using the catheter of this invention. It is a schematic explanatory drawing which shows the 3rd treatment method using the catheter of this invention. It is a schematic explanatory drawing which shows the 4th treatment method using the catheter of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a catheter according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a partially omitted side view of a catheter 10 according to an embodiment of the present invention. This catheter 10 is a medical instrument that is introduced into a living organ such as a blood vessel and used to inspect and treat a lesion in the living organ. It is configured as a guiding catheter used for coronary angioplasty).

  In PTCA using the catheter 10 configured as a guiding catheter, a long shaft 12 is inserted into a blood vessel (eg, femoral artery, brachial artery, radial artery) via a sheath introducer 130 (insertion tool) After the distal end reaches the coronary ostia via the aorta, for example, a balloon catheter 146 is inserted into the shaft 12 to guide the balloon 148 from the coronary ostium to the stenosis occurring inside the coronary artery. The stenosis is expanded and treated by expanding at the part.

  As shown in FIG. 1, the catheter 10 includes a thin and long shaft 12, a hub 13 provided on the proximal side of the shaft 12, and a telescopic mechanism 14 provided between the shaft 12 and the hub 13. And a tightening mechanism 16 provided outside the expansion / contraction mechanism 14 and a kink protector 18 provided at the tip of the expansion / contraction mechanism 14, and the shaft 12 is axially moved with respect to the hub 13 by the action of the expansion / contraction mechanism 14. The position of the shaft 12 after the position adjustment can be fixed by the action of the tightening mechanism 16. In the following description of the catheter 10, the left side in FIGS. 1, 2A, 2B, 3A, 3B, 4A, 6A, and 6B is the “distal end”, and the right side is the “proximal end (rear end)”. "

  The shaft 12 is formed in a cylindrical shape, and is moderately flexible and moderate so that the operator can smoothly insert it into a living organ such as a blood vessel while grasping and operating the proximal end side thereof. It is comprised with the resin etc. which have intensity | strength. The tip portion of the shaft 12 has a straight shape in the illustrated example, but may have a curved shape depending on the application.

  The length of the shaft 12 is set to, for example, about 75 to 130 cm, preferably about 85 to 120 cm in consideration of the length from the insertion site (puncture site) into the blood vessel of the human body to the coronary artery and operability. The The effective length of the shaft 12 when the shaft is most extended by the expansion / contraction mechanism 14 is set to about 95 to 130 cm, for example, and the effective length of the shaft 12 when the shaft 12 is shortened by the expansion / contraction mechanism 14 is, for example, 75 It is set to about ~ 110 cm.

  Inside the shaft 12, a guide wire 134 (see FIGS. 7 and 8) and a balloon catheter 146 (see FIG. 8) for guiding the catheter 10 to an inlet such as a coronary artery are inserted.

  The outer diameter of the shaft 12 is set to 3.3 mm or less over its entire length. In particular, when used in a procedure of introducing from a human brachial artery or radial artery and engaging the coronary artery mouth via the aorta, the outer diameter of the shaft 12 is not more than 2.7 mm (preferably 2.1 mm). The following is recommended. Moreover, when using for the procedure which advances the front-end | tip of the shaft 12 to the back of a coronary artery, the outer diameter of the shaft 12 is good to set to 1.8 mm or less (preferably 1.5 mm or less) over the full length.

  The hub 13 is a hollow member that holds the proximal end of the expansion / contraction mechanism 14 at its distal end, and a connection port or a treatment device for connecting other instruments such as a syringe is inserted into the proximal end of the hub 13. A port 13a functioning as an insertion port is provided. The kink protector 18 is for preventing bending (kink) at the connection portion of the shaft 12 to the expansion / contraction mechanism 14, and is a resin having an appropriate flexibility and rigidity formed in a tapered tube shape, for example. It is a made member.

  2A to 3B are partially omitted vertical sectional views schematically showing the configuration of the expansion / contraction mechanism 14. In these drawings, for easy understanding of the structure, the structure of the expansion / contraction mechanism 14 and its peripheral part is shown as being short in the axial direction and large in the radial direction. The expansion / contraction mechanism 14 is provided between the shaft 12 and the hub 13 and includes a plurality of tubular members 22, 24, and 26 that are slidable in the axial direction within a restricted range and have a nested structure. The nesting structure refers to a structure in which members having hollow portions having similar shapes and different sizes are sequentially inserted.

  The expansion / contraction mechanism 14 according to the illustrated configuration example includes three tubular members 22, 24, and 26. Below, when distinguishing these three tubular members 22, 24, and 26, they are called the first tubular member 22, the second tubular member 24, and the third tubular member 26 in order from the inside. Each tubular member 22, 24, 26 has a hollow cylindrical shape, and a material having appropriate flexibility and rigidity so as to be elastically deformed radially inward when pressed from the outside by the tightening mechanism 16, For example, it is made of a resin material.

  Of the plurality of tubular members 22, 24, and 26 that constitute the expansion / contraction mechanism 14, the first tubular member 22 located on the innermost side is connected to the proximal end portion of the shaft 12. The first tubular member 22 includes a first diameter-expanded portion 28 that forms an intermediate position in the axial direction, a first tip diameter-reduced portion 30 provided on the distal end side of the first diameter-expanded portion 28, and a base of the diameter-expanded portion. And a first proximal end reduced diameter portion 32 provided on the end side.

  The base end portion of the shaft 12 is inserted into the first tip reduced diameter portion 30, and the outer peripheral surface of the base end portion of the shaft 12 and the inner peripheral surface of the first tip reduced diameter portion 30 are joined. The first tip diameter-reduced portion 30 and the first diameter-expanded portion 28 are connected by a tapered portion 34 that gradually decreases in diameter toward the tip side. The first enlarged diameter portion 28 and the first proximal end reduced diameter portion 32 are connected by a tapered portion 36 that gradually increases in diameter toward the distal end.

  The second tubular member 24 is not connected to either the shaft 12 or the hub 13. The second tubular member 24 includes a second diameter-expanded portion 38 that constitutes a midway position in the axial direction, a second tip diameter-reduced portion 40 provided on the distal end side of the second diameter-expanded portion 38, and a second diameter-expanded portion. 38 and a second proximal end reduced diameter portion 42 provided on the proximal end side of 38. The second tip reduced diameter portion 40 and the second diameter enlarged portion 38 are connected by a taper portion 44 that gradually decreases in diameter toward the tip side. The second enlarged diameter portion 38 and the second proximal end reduced diameter portion 42 are connected by a tapered portion 46 that gradually increases in diameter toward the distal end.

  The inner diameter of the second enlarged portion 38 is set to be substantially the same as or slightly larger than the outer diameter of the first enlarged portion 28. In the case of the present embodiment, as shown in FIG. 2A, a slight gap is formed between the first diameter-expanded portion 28 and the second diameter-expanded portion 38 in a state where the telescopic mechanism 14 is not tightened by the tightening mechanism 16. The The second enlarged diameter portion 38 is longer in the axial direction than the first enlarged diameter portion 28.

  The inner diameter of the second tip reduced diameter portion 40 is set to be the same as or slightly larger than the outer diameter of the first tip reduced diameter portion 30. The first tip reduced diameter portion 30 is inserted into the second tip reduced diameter portion 40. The inner diameter of the second proximal end reduced diameter portion 42 is set to be substantially the same as or slightly larger than the outer diameter of the first proximal end reduced diameter portion 32. The first proximal end reduced diameter portion 32 is inserted into the second proximal end reduced diameter portion 42.

  The third tubular member 26 located on the outermost side among the plurality of tubular members 22, 24, 26 constituting the expansion / contraction mechanism 14 is connected to the tip of the hub 13. The third tubular member 26 includes a third diameter-expanded portion 48 that constitutes an intermediate position in the axial direction, a third tip diameter-reduced portion 50 provided on the distal end side of the third diameter-expanded portion 48, and a third diameter-expanded portion. And a third base end reduced diameter portion 52 provided on the base end side of 48.

  The third tip reduced diameter portion 50 is inserted into the proximal end of the kink protector 18, and the outer peripheral surface of the third tip reduced diameter portion 50 and the inner peripheral surface of the kink protector 18 are joined. The third proximal end reduced diameter portion 52 is inserted into the distal end of the hub 13, and the outer peripheral surface of the third proximal end reduced diameter portion 52 and the inner peripheral surface of the hub 13 are joined. The third tip diameter-reduced portion 50 and the third diameter-expanded portion 48 are connected by a tapered portion 54 that gradually decreases in diameter toward the tip side. The third enlarged diameter portion 48 and the third proximal end reduced diameter portion 52 are connected by a tapered portion 56 that gradually increases in diameter toward the distal end.

  The inner diameter of the third enlarged portion 48 is set to be substantially the same as or slightly larger than the outer diameter of the second enlarged portion 38. In the case of the present embodiment, as shown in FIG. 2A, a slight gap is formed between the second diameter-expanded portion 38 and the third diameter-expanded portion 48 in a state where the extension mechanism 14 is not tightened by the tightening mechanism 16. The The third enlarged diameter portion 48 is longer in the axial direction than the second enlarged diameter portion 38.

  The inner diameter of the third tip reduced diameter portion 50 is set to be the same as or slightly larger than the outer diameter of the second tip reduced diameter portion 40. The second tip reduced diameter portion 40 is inserted into the third tip reduced diameter portion 50. The inner diameter of the third proximal end reduced diameter portion 52 is set to be the same as or slightly larger than the outer diameter of the second proximal end reduced diameter portion 42. The second proximal end reduced diameter portion 42 is inserted into the third proximal end reduced diameter portion 52.

  Since the expansion / contraction mechanism 14 is configured as described above, the first tubular member 22 can move in the axial direction within a range restricted in the second tubular member 24, and the second tubular member 24 has a third configuration. It is movable in the axial direction within a range regulated in the tubular member 26. Therefore, the shaft 12 is moved in the axial direction with respect to the hub 13, and the length from the tip of the shaft 12 to the tip of the kink protector 18, that is, the effective length of the shaft 12 can be arbitrarily changed.

  Here, FIG. 3A shows a state in which the first tubular member 22 has moved to the most distal end side in the second tubular member 24 and the second tubular member 24 has moved to the most distal end side in the third tubular member 26. . In this state, the effective length of the shaft 12 is maximum within the adjustment range. On the other hand, FIG. 3B shows a state in which the first tubular member 22 moves most proximally in the second tubular member 24 and the second tubular member 24 moves most proximally in the third tubular member 26. is there. In this state, the effective length of the shaft 12 is minimum within the adjustment range.

  The adjustable range of the effective length of the shaft 12 by the telescopic mechanism 14 (the difference between the longest and shortest effective length of the shaft 12) is not particularly limited, but is, for example, about 30 to 200 mm, preferably 40. It is about ~ 100mm.

  As shown in FIG. 3A, when the first tubular member 22 is located on the most distal side within the movable range, the most proximal position of the first proximal end reduced diameter portion 32 is the second proximal end of the second tubular member 24. It extends to the vicinity or inside of the most distal position of the reduced diameter portion 42. Similarly, when the second tubular member 24 is located on the most distal side within the movable range, the most proximal position of the second proximal end reduced diameter portion 42 is the third proximal end reduced diameter of the third tubular member 26. It extends to the vicinity of the frontmost position of the portion 52 or to the inside.

  When the effective length of the shaft 12 is the maximum by setting the lengths of the first proximal end reduced diameter portion 32 and the second proximal end reduced diameter portion 42 as described above, the first proximal end reduced diameter portion 32 and No gap in the axial direction is formed between the second base end reduced diameter portion 42 and between the second base end reduced diameter portion 42 and the third base end reduced diameter portion 52. Therefore, when a thin wire (for example, a guide wire) is inserted from the proximal end side of the hub 13, the space between the first proximal reduced diameter portion 32 and the second enlarged diameter portion 38 or the second proximal reduced diameter. A thin wire rod does not enter the space between the portion 42 and the third enlarged diameter portion 48, and the wire rod can be inserted smoothly.

  Further, the most proximal end portions of the first to third proximal end reduced diameter portions 32, 42, 52 are on the proximal end side of the tubular members 22, 24, 26 by the thickness of the tubular members 22, 24, 26. The taper may be tapered so that the thickness decreases from the inside to the outside as it goes to. With this configuration, when a thin wire is inserted from the proximal end side of the hub 13, even if the wire comes into contact with the most proximal end portion of the tubular members 22, 24, 26, it is provided at the most proximal end portion. Since the taper is guided inward by the action of the taper, the wire can be inserted smoothly.

  The expansion / contraction mechanism 14 according to the illustrated configuration example is configured by the three tubular members 22, 24, and 26. However, the configuration is not limited thereto, and may be configured by two or four or more tubular members. . In this case, among the plurality of tubular members, the tubular member other than the outermost one is the most proximal end of the proximal end reduced diameter portion of the tubular member when the tubular member is located on the most distal side in the movable range. The position may extend to the vicinity of the distal end of the proximal end reduced diameter portion of the tubular member directly surrounding the tubular member or to the inside. In addition, the length in the axial direction of the enlarged diameter portion of each tubular member (excluding the innermost one) is longer than the length in the axial direction of the enlarged diameter portion of the tubular member disposed inside the tubular member.

  Next, the configuration of the tightening mechanism 16 will be described. The tightening mechanism 16 is provided on the outside of the expansion / contraction mechanism 14 and releases the pressure applied to the expansion / contraction mechanism 14 by pressing the expansion / contraction mechanism 14 from the outside so that the tubular members 22, 24, 26 are brought into close contact with each other. It can be switched to a tightening release state. 2A and 2B, the tightening mechanism 16 includes a cylindrical elastic body (clamping member) 60 that directly surrounds the telescopic mechanism 14, a cylindrical body 62 that houses the cylindrical elastic body 60, and a cylindrical shape. And a pressing member 64 that presses the elastic body 60 in the axial direction.

  The cylindrical elastic body 60 has a tubular shape (hollow cylindrical shape) surrounding the expansion / contraction mechanism 14, and is configured so that the inner diameter is reduced by being compressed in the axial direction. The constituent material of the cylindrical elastic body 60 is not particularly limited. For example, various rubbers such as silicone rubber, fluororubber, isoprene, natural rubber, various resins such as polyurethane, polyamide elastomer, polybutadiene, soft vinyl chloride, or the like. The thing etc. which combined 2 or more among these are mentioned.

  The cylindrical body 62 is a hollow (hollow cylindrical) member surrounding the cylindrical elastic body 60, and is made of a material having an appropriate rigidity, for example, a hard resin material. An annular housing portion that holds the elastic body 60 is formed. The cylindrical body 62 is joined to the third tubular member 26 and the kink protector 18 so as not to be displaced in the axial direction and the circumferential direction with respect to the expansion / contraction mechanism 14 (third tubular member 26). A male screw portion 62 a is formed on the outer peripheral portion including the proximal end of the cylindrical body 62.

  The pressing member 64 has an inner cylinder portion 66 and a cylindrical rotation operation portion 68 that concentrically surrounds the inner cylinder portion 66, is disposed concentrically with the cylindrical body 62, and is attached to the cylindrical body 62. It is provided so as to be rotatable. The inner cylindrical portion 66 and the rotation operation portion 68 form an annular groove 70 that is open to the distal end side.

  The rotation operation unit 68 is a part that a user (operator) pinches and rotates with a finger. It is preferable that anti-slip ribs protruding outward in the radial direction and extending along the axial direction of the rotation operation unit 68 are formed on the outer peripheral surface of the rotation operation unit 68 at intervals in the circumferential direction. A female screw portion 68 a that is screwed into a male screw portion 62 a provided on the outer peripheral surface of the base end of the cylindrical body 62 is formed on the inner peripheral portion of the rotation operation portion 68. Therefore, when the rotation operation unit 68 is rotated, the rotation operation unit 68 moves in the axial direction with respect to the cylindrical body 62 by screwing between the female screw portion 68a and the male screw portion 62a.

  When the rotation operation portion 68 is rotated and moved in the distal direction, the cylindrical elastic body 60 is pressed in the axial direction by the inner cylinder portion 66 and elastically deforms, and the inner diameter of the cylindrical elastic body 60 is reduced. At this time, the first to third diameter-expanded portions 28, 38, and 48 of the first to third tubular members 22, 24, and 26 constituting the expansion / contraction mechanism 14 are inward by the inner peripheral portion of the cylindrical elastic body 60. It elastically deforms, and the first to third diameter-expanded portions 28, 38, and 48 are in close contact with each other at their inner and outer peripheral portions (see FIG. 2B). Thereby, since the relative displacement in the axial direction and the circumferential direction between the first to third tubular members 22, 24, 26 is prevented, the effective length of the shaft 12 can be suitably held at an arbitrary length, and the hub 13 The torque transmission to the shaft 12 can be improved, and the first to third enlarged diameter portions 28, 38, 48 can be sealed to ensure liquid tightness.

  When the rotation operation portion 68 is rotated in the reverse direction and moved in the proximal direction, the pressure on the tightening member by the inner tube portion 66 is released, so that the shape of the tightening member is restored by an elastic force, and again Returning to the state shown in FIG. 2A. Therefore, relative displacement in the axial direction between the first to third tubular members 22, 24, and 26 is allowed, and the effective length of the shaft 12 can be adjusted to an arbitrary length.

  The catheter 10 according to the present embodiment is basically configured as described above, and the operation and effect thereof will be described below.

  According to the catheter 10 according to the present embodiment, the shaft 12 and the hub 13 are connected to each other by the telescopic mechanism 14 having a plurality of tubular members 22, 24, 26 having a nested structure. By moving 12 in the axial direction, the effective length of the shaft 12 can be changed (expanded). Therefore, when the length of the shaft 12 is insufficient, it is possible to reliably reach a desired position (for example, the coronary artery ostium) in the living organ by extending the effective length of the shaft 12.

  When the shaft 12 is too long, by shortening the effective length of the shaft 12, it is possible to suppress the occurrence of kinking and kinking of the portion of the shaft 12 exposed to the outside from the base end of the sheath introducer 130, The distal end of a treatment device (for example, a balloon catheter) used by being inserted through the lumen of the catheter 10 can be reliably projected from the distal end of the shaft 12.

  According to the catheter 10 according to the present embodiment, it is not necessary to prepare a plurality of catheters having different lengths, and it is excellent in medical economic efficiency. Further, the replacement work of the catheter 10 is unnecessary, and the burden on the patient can be reduced.

  Further, according to the catheter 10 according to the present embodiment, the first to third diameter-expanded portions 28, 38, and 48 are adjusted when the extension mechanism 14 is tightened from the outside by the tightening mechanism 16 after adjusting the effective length of the shaft 12. Since relative displacement between each other is prevented, the effective length of the shaft 12 can be suitably maintained at an arbitrary length, torque transmission from the hub 13 to the shaft 12 can be improved, and the first to third diameter-expanded portions 28, 38 and 48 can be sealed to ensure liquid tightness.

  As described above, in the catheter 10 according to the present embodiment, when the first tubular member 22 is located on the most distal side within the movable range, the most proximal end position of the first proximal end reduced diameter portion 32 is the second tubular end. When the second tubular member 24 extends to the vicinity or inside of the most distal end position of the second proximal end reduced diameter portion 42 of the member 24 and the second tubular member 24 is located at the most distal end side within the movable range, the second proximal end reduced diameter portion 42. The most proximal end position of the third tubular member 26 extends to the vicinity or inside of the most distal end position of the third proximal end reduced diameter portion 52. Since it is configured in this manner, when a thin wire (for example, a guide wire) is inserted from the proximal end side of the hub 13, a space between the first proximal reduced diameter portion 32 and the second enlarged diameter portion 38. Alternatively, the thin wire rod does not enter the space between the second proximal end reduced diameter portion 42 and the third enlarged diameter portion 48, and the wire rod can be inserted smoothly.

  In the catheter 10 according to the present embodiment, the telescopic mechanism 14 is tightened from the outside by the cylindrical elastic body 60 whose inner diameter is reduced by the movement of the pressing member 64 in the axial direction, so the first to third diameter-expanded portions 28 and 38 are tightened. , 48 can be brought into close contact with each other. Therefore, good sealing performance can be obtained.

  In the catheter 10 according to the present embodiment, instead of the above-described tightening mechanism 16, a tightening mechanism 16a according to a modification shown in FIGS. 4A and 4B may be applied. The tightening mechanism 16a includes a plurality of (four in the illustrated example) pressing pieces (clamps) provided at intervals in the circumferential direction along the outer periphery of the telescopic mechanism 14 (specifically, the third tubular member 26). Attached member) 72, a hollow cylindrical screw member 74 provided with a male screw portion 74a on the outer peripheral portion, and a hollow shape (tubular shape) provided with a female screw portion 76a screwed into the male screw portion 74a on the inner peripheral portion. ) Pressing member 76.

  The pressing piece 72 is a member that is fixed to the tip of the hub 13, extends along the axial direction of the expansion / contraction mechanism 14, and can be elastically deformed inward by being pressed from the outside by the pressing member 76. It is composed of a material having elasticity and rigidity, for example, a resin material or a metal material. The pressing piece 72 according to the illustrated configuration example is configured as a separate member from the hub 13, but may be integrally formed with the hub 13. A tapered outer surface 72a is provided on the outer end of each pressing piece 72 so as to approach the central axis of the telescopic mechanism 14 toward the distal end.

  The screw member 74 is fixed to the tip of the hub 13 in the illustrated configuration example. The screw member 74 is configured as a separate member from the hub 13, but may be integrally formed with the hub 13.

  The pressing member 76 is a tubular (hollow cylindrical) member that is provided so that the position in the axial direction can be changed with respect to the expansion / contraction mechanism 14 and surrounds the expansion / contraction mechanism 14 and the plurality of pressing pieces 72. A tapered inner surface 76 b that decreases in diameter toward the tip is formed on the inner peripheral portion of the pressing member 76. The inclination of the tapered inner surface 76 b is set to be substantially the same as the inclination of the tapered outer surface 72 a formed on the pressing piece 72. The kink protector 18 is integrally fixed to the tip of the pressing member 76. The kink protector 18 may be integrally fixed to the tip of the third tubular member 26 in the same manner as the configuration shown in FIG. 2A and the like.

  A female screw portion 76 a that is screwed into the male screw portion 74 a of the screw member 74 is formed on the inner peripheral portion of the proximal end of the pressing member 76. Therefore, when the pressing member 76 is rotated, the pressing member 76 moves in the axial direction with respect to the expansion / contraction mechanism 14 and the pressing piece 72 by screwing between the female screw portion 76a and the male screw portion 74a.

  In the tightening mechanism 16 configured as described above, when the pressing member 76 is rotated and moved in the proximal direction, each pressing piece 72 is pressed radially inward by the tapered inner surface 76 b of the pressing member 76. Due to the elastic deformation caused by this, the tip portion is displaced radially inward. At this time, the first to third diameter-expanded portions 28, 38, 48 of the first to third tubular members 22, 24, 26 constituting the expansion / contraction mechanism 14 are pressed inward by the plurality of pressing pieces 72. It elastically deforms, and the first to third diameter-expanded portions 28, 38, and 48 are in close contact with each other at their inner and outer peripheral portions. Thereby, since the relative displacement in the axial direction and the circumferential direction between the first to third tubular members 22, 24, 26 is prevented, the effective length of the shaft 12 can be suitably held at an arbitrary length, and the hub 13 The torque transmission to the shaft 12 can be improved, and the first to third tubular members 22, 24, 26 can be sealed to ensure liquid tightness.

  In the case of the tightening mechanism 16a, since the plurality of pressing pieces 72 are displaced inward by the movement of the pressing member 76 having the tapered inner surface 76b in the axial direction, the telescopic mechanism 14 is tightened from the outside. The inner peripheral surface and the outer peripheral surface of the tubular members 22, 24, and 26 can be reliably adhered to each other. Therefore, good sealing performance can be obtained.

  When the pressing member 76 is rotated and moved in the distal direction, the pressing of the pressing piece 72 by the tapered inner surface 76b is released, so that the shape of the pressing piece 72 is restored by an elastic force. Therefore, relative displacement in the axial direction between the first to third tubular members 22, 24, and 26 is allowed, and the effective length of the shaft 12 can be adjusted to an arbitrary length.

  In the catheter 10, a plurality of tubular members (in the present embodiment, the first to third tubular members 22, 24, 26) other than the outermost one (in the present embodiment, the third tubular member 26). The outer peripheral portion of the tubular member (in the present embodiment, the first and second tubular members 22, 24) is provided with an outer concave portion or an outer convex portion extending in the axial direction, and the innermost of the plurality of tubular members. The inner peripheral portion of the tubular member (in the present embodiment, the second and third tubular members 24, 26) other than the one located in (in the present embodiment, the first tubular member 22) extends in the axial direction. An inner convex portion or an inner concave portion is provided, and the outer concave portion or the outer convex portion may be engaged with the inner convex portion or the inner concave portion. Some configuration examples are shown in FIGS. 5A to 5C.

  5A is a cross-sectional view taken along line VA-VA in FIG. 2A. In FIG. 5A, the tightening mechanism 16 is not shown (the same applies to FIGS. 5B and 5C). In the telescopic mechanism 14 shown in FIG. 5A, a mountain-shaped portion (outer convex portion) 80 and a valley-shaped portion (outer concave portion) 82 extending in the axial direction are alternately arranged in the circumferential direction on the outer peripheral portion of the first diameter-expanded portion 28. A plurality of mountain-shaped portions (inner convex portions) 84 and valley-shaped portions (inner concave portions) 86 extending in the axial direction are provided alternately in the circumferential direction on the inner peripheral portion of the second enlarged diameter portion 38. A plurality of mountain-shaped portions (outer convex portions) 88 and valley-shaped portions (outer concave portions) 90 extending in the axial direction are alternately provided in the circumferential direction on the outer peripheral portion of the second enlarged diameter portion 38, and the third A plurality of mountain-shaped portions (inner convex portions) 92 and valley-shaped portions (inner concave portions) 94 extending in the axial direction are alternately provided in the inner peripheral portion of the enlarged diameter portion 48 in the circumferential direction.

  In the telescopic mechanism 14a shown in FIG. 5B, a plurality of ridges (outer convex portions) 96 and groove portions (outer concave portions) 98 extending in the axial direction are provided alternately in the circumferential direction on the outer peripheral portion of the first enlarged diameter portion 28a. A plurality of ridges (inner convex portions) 100 and groove portions (inner concave portions) 102 extending in the axial direction are alternately provided in the inner peripheral portion of the second enlarged diameter portion 38a in the circumferential direction. A plurality of protrusions (outer convex portions) 104 and groove portions (outer concave portions) 106 extending in the axial direction are alternately provided in the circumferential direction on the outer peripheral portion of the portion 38a, and the inner peripheral portion of the third enlarged diameter portion 48a. A plurality of ridges (inner convex portions) 108 and grooves (inner concave portions) 110 extending in the axial direction are alternately provided in the circumferential direction.

  In the telescopic mechanism 14b shown in FIG. 5C, a plurality of ridges (outer convex portions) 112 extending in the axial direction are provided in the circumferential direction on the outer peripheral portion of the first enlarged diameter portion 28b, and the second enlarged diameter portion 38b. A plurality of groove portions (inner concave portions) 114 extending in the axial direction are provided in the inner peripheral portion, and a groove portion (outer concave portion) 116 extending in the axial direction is provided on the outer peripheral portion of the second enlarged diameter portion 38b. Are provided in the circumferential direction, and a plurality of protrusions (inner convex portions) 118 extending in the axial direction are provided in the circumferential direction on the inner circumferential portion of the third enlarged diameter portion 48b. A groove may be provided instead of the protrusion 112 of the first enlarged diameter portion 28b, and a protrusion may be provided instead of the groove 114 of the second enlarged diameter portion 38b. A protrusion may be provided instead of the groove 116 of the second enlarged diameter portion 38b, and a groove may be provided instead of the protrusion 118 of the third enlarged diameter portion 48b.

  When the concave and convex shapes are provided on the outer and inner peripheral portions of the first to third tubular members 22, 24, and 26 as in the telescopic mechanisms 14, 14 a, and 14 b shown in FIGS. 5A to 5C, the tightening mechanism 16 When the telescopic mechanism 14 is tightened by the first to third tubular members 22, 24, and 26 are engaged with each other by the concavo-convex shapes provided on the inner peripheral portion and the outer peripheral portion thereof, and relative rotation is prevented. Therefore, the torque transmission from the hub 13 to the shaft 12 can be further improved.

  Like the expansion / contraction mechanism 14c shown in FIGS. 6A and 6B, among the plurality of tubular members (first to third tubular members 22, 24, 26), those other than the outermost one (third tubular member 26) are used. Other than the outer peripheral portion of the enlarged diameter portion (first and second enlarged diameter portions 28, 38) of the tubular member (first and second tubular members 22, 24) and the innermost portion (first tubular member 22) Rough surfaces 120, 121, 122, and 123 are provided on the inner peripheral portions of the enlarged diameter portions (second and third enlarged diameter portions 38 and 48) of the tubular members (second and third tubular members 24 and 26), respectively. May be provided.

  6A and 6B, when the telescopic mechanism 14c is tightened by the tightening mechanism 16, the first to third tubular members 22 (28c), 24 (38c), and 26 (48c) are connected to each other. The frictional resistance between the first to third tubular members 22 (28c), 24 (38c), 26 (48c) is increased by the rough surfaces 120, 121, 122, 123 provided on the inner peripheral portion and the outer peripheral portion, The torque transmission from the hub 13 to the shaft 12 can be further improved. In addition, you may provide the rough surface 120, 121, 122, 123 mentioned above in the outer peripheral part and outer peripheral part of the 1st-3rd tubular member which has the uneven | corrugated shape shown to FIG. 5A-FIG. 5C.

  The catheter 10 of the present invention can be applied to a method for treating a stenosis occurring in a blood vessel. This method is a method for treating a stenosis occurring in a blood vessel using a catheter 10 configured so that the effective length of the shaft 12 can be shortened with respect to the hub 13, and before the most distal portion of the catheter 10. The step of advancing the catheter 10 and the balloon catheter into the blood vessel with the balloon placed in the lumen at the position, the step of positioning the most distal end of the catheter 10 in the stenosis, and without changing the position of the hub 13 of the catheter 10 Retracting the distal end of the catheter 10 by reducing the effective length of the shaft 12 relative to the hub 13 and positioning the balloon of the balloon catheter within the stenosis. Thereby, treatment of a stenosis part can be performed rapidly.

  Next, in relation to the method of using the catheter 10 of the present invention, the first to fourth treatment methods will be described by taking PTCA (percutaneous angioplasty) as an example.

  First, the first treatment method will be described. In the first treatment method, the catheter 10 according to the present embodiment is used as a guiding catheter for PTCA, inserted to the periphery of the coronary artery, and the stenosis portion generated in the coronary artery is expanded. The catheter 10 is thin (for example, 4Fr) so that it can be inserted to the periphery of the coronary artery, and the shape is generally straight, but the tip may be slightly bent.

  The catheter 10 is in an initial state in which the telescopic mechanism 14 is tightened by the tightening mechanism 16 so that the shaft 12 does not move in the axial direction with respect to the hub 13. As shown in FIG. 7, for example, the sheath introducer 130 is punctured into a blood vessel (for example, femoral artery) 132 by the Seldinger method, and the catheter 10 with the guide wire 134 inserted is inserted into the sheath introducer 130. Then, the distal end of the shaft 12 is inserted into the blood vessel 132 from the distal end opening of the sheath introducer 130 with the guide wire 134 preceding the distal end of the shaft 12.

  Next, the catheter 10 and the guide wire 134 are gradually sent in the direction of the arrow in FIG. 7 and inserted into the ascending aorta 140 through the aortic arch 138 of the aorta 136 as shown in FIG. At this time, an operation in which the guide wire 134 is taken in and out and the catheter 10 is advanced and retracted and rotated appropriately is performed so that the tip of the shaft 12 passes through the bent portion of the blood vessel.

  When the catheter 10 is introduced to the vicinity of the left coronary artery opening 142 of the heart 141, the guide wire 134 is operated to engage the distal end portion of the shaft 12 with the left coronary artery opening 142, and the position of the distal end portion of the catheter 10 is fixed. Note that the first treatment method can be applied to both the left and right coronary arteries, but here, a case will be described in which the stenosis 150 occurring in the left coronary artery 144 is treated. This also applies to the second treatment method.

  After the distal end of the catheter 10 is inserted into the left coronary artery opening 142, the guide wire 134 is removed from the catheter 10, and a syringe is connected to the branch of the Y connector 131 (see FIG. 7) attached to the rear end of the hub 13. Inject contrast medium. The injected contrast medium passes through the catheter 10 and is ejected from the distal end opening into the left coronary artery 144 which is the target site. As a result, the insertion position of the distal end of the catheter 10 into the left coronary artery opening 142 can be confirmed, and the left coronary artery 144 can be imaged.

  Next, a balloon catheter 146 as a treatment catheter is inserted through the rear end portion of the Y connector 131 and the lumen of the catheter 10. In this case, the balloon 148 provided at the distal end of the balloon catheter 146 is arranged in front of the catheter 10 to fix (hold) the position of the balloon 148 in the catheter 10.

  Next, the position of the balloon 148 in the catheter 10 is fixed, and the catheter 10 and the balloon catheter 146 are advanced into the left coronary artery 144 with the guide wire 134 inserted through the balloon catheter 146 in advance. Then, it is inserted into the stenosis 150, which is a lesion. FIG. 8 shows the situation at this time. In the left coronary artery 144 on the distal side of the left coronary artery opening 142, the vicinity of the distal end of the catheter 10 is shown in cross section. At the time of this insertion, the balloon 148 is housed in front of the most distal end of the catheter 10, so that an excellent penetrating force is exerted on a lesion such as a chronic total occlusion lesion (CTO).

  When the catheter 10 and the balloon catheter 146 are inserted into the narrowed portion 150, the tightening mechanism 16 of the catheter 10 is operated to release the tightening of the expansion / contraction mechanism 14 by the tightening mechanism 16, and the function of the expansion / contraction mechanism 14 is used. Then, the shaft 12 is moved to the front side (base end side). By retracting the tip of the shaft 12 in this way, the balloon 148 is projected from the tip opening of the shaft 12.

  As described above, when the catheter 10 of the present invention is used, the balloon 148 is rapidly protruded when the distal end portion of the shaft 12 is retracted by the function of the expansion / contraction mechanism 14 to reach the position of the stenosis 150 as a lesion. Can be made. Moreover, it is not necessary to move the hub 13 at the time of operation at this time. That is, if the proximal end portion (sheath valve body) of the sheath introducer 130, the hub 13 of the catheter 10 and the balloon catheter 146 are integrated and fixed by hand, the operation of retracting the shaft 12 can be easily performed by one person. Is possible.

  When the balloon 148 protrudes from the distal end opening of the shaft 12, the extension mechanism 14 is tightened by the tightening mechanism 16 so that the shaft 12 does not move back and forth (in the axial direction). Next, the stenosis 150 is treated with the balloon 148. That is, the balloon 148 is expanded to push the stenosis 150 from the inside. When the stenosis 150 is expanded, the balloon 148 is deflated. Next, after operating the tightening mechanism 16 to release the tightening of the telescopic mechanism 14, the shaft 12 is moved to the distal end side, and the balloon 148 is returned into the shaft 12. Next, the catheter 10 and the balloon catheter 146 are removed from the body.

  Next, a second treatment method will be described with reference to FIG. In the second treatment method, the catheter 10 according to the present embodiment is used as a guiding catheter for PTCA, inserted to the periphery of the left coronary artery 144, and already in the stenosis 150 and the left coronary artery 144 generated in the left coronary artery 144. The stenosis portions 151 and 152 generated on the distal side of the indwelling stents 154 and 155 are expanded. The catheter 10 may be the same as that used in the first treatment method.

  In the second treatment method, the catheter 10 is inserted into the blood vessel via the sheath introducer 130 to reach the ascending aorta 140, the catheter 10 is engaged with the left coronary artery opening 142, and then the contrast agent is added to the left coronary artery. 144, and then the balloon catheter 146 is inserted into the catheter 10, and the balloon 148 provided at the distal end of the balloon catheter 146 is disposed in front of the catheter 10 so that the balloon 148 is inserted into the catheter 10. The procedure up to the procedure of fixing (holding) the position is the same as in the first treatment method.

  Thereafter, in the second treatment method, the position of the balloon 148 in the catheter 10 is fixed, and the catheter 10 and the balloon catheter 146 are placed in the left coronary artery with the guide wire 134 inserted through the balloon catheter 146 in advance. Advance into 144 and insert into constriction 150. Then, after releasing the tightening of the expansion / contraction mechanism 14 by the tightening mechanism 16, the shaft 12 is moved to the near side, and the balloon 148 is protruded from the distal end opening of the shaft 12.

  Next, the telescopic mechanism 14 is tightened by the tightening mechanism 16 so that the shaft 12 does not move back and forth (in the axial direction), and the stenosis 150 is treated with the balloon 148. When the stenosis 150 is expanded, the balloon 148 is deflated. Next, after operating the tightening mechanism 16 to release the tightening of the telescopic mechanism 14, the shaft 12 is moved to the distal end side, and the balloon 148 is returned into the shaft 12.

  As shown in FIG. 9, previously deployed stents 154, 155 are present in the left coronary artery 144. FIG. Therefore, in the second treatment method, the catheter 10 and the balloon catheter 146 are passed through the stent 154 on the near side. In this case, since the balloon 148 is accommodated in the shaft 12, the balloon 148 is not caught by the stent 154. The guide wire 134 and the balloon catheter 146 alone cannot pass the stent 154, but the balloon 148 can be fed to a position beyond the stent 154 by the above method.

  In this way, the catheter 10 and the balloon catheter 146 are passed through the stent 154 and inserted into the stenosis 151. FIG. 9 shows the situation at this time. The catheter 10 placed in the left coronary artery 144 is shown in cross section near its distal end. Then, the stenosis 151 is treated in the same procedure as when the stenosis 150 is treated. After the stenosis 151 has been treated, the catheter 10 and the balloon catheter 146 are advanced further to the left coronary artery 144, passed through the distal stent 155, inserted into the stenosis 152, and the stenosis 152 is removed by the same procedure as described above. treat. After treating the stenosis 152, the catheter 10 and balloon catheter 146 are removed from the body.

  As a modification of the second treatment method, the stenosis 150 to 152 may be treated by the following procedure. Hereinafter, a modified example of the second treatment method will be described with reference to FIG.

  With the effective length of the shaft 12 of the catheter 10 being the shortest, the catheter 10 is inserted into the blood vessel 132 to reach the ascending aorta 140 in the same manner as in FIG. 7, and the distal end of the catheter 10 reaches the left coronary artery opening 142. Engage and eject contrast agent into the left coronary artery 144. Next, the balloon 148 is projected from the distal end opening of the catheter 10 and advanced into the left coronary artery 144, the balloon 148 is inserted into the stenosis 150, and the stenosis 150 is treated by expanding the balloon 148.

  Thereafter, the diameter of the balloon 148 is reduced, and then the balloon 148 is pulled back to the front end of the catheter 10 and stored again. Next, after releasing the tightening of the telescopic mechanism 14 by the tightening mechanism 16 and extending the telescopic mechanism 14 (without changing the position of the proximal portion (hub 13) outside the body of the catheter 10). The tip of the shaft 12 is advanced into the left coronary artery 144 and the existing stent 154 is passed through. Next, the balloon 148 is inserted into the stenosis 151, and the stenosis 151 is treated by expanding the balloon 148. Thereafter, the stenosis 152 is treated in the same procedure. After treating the stenosis 152, the catheter 10 and balloon catheter 146 are removed from the body.

  Next, a third treatment method will be described with reference to FIG. In the third treatment method, the catheter 10 according to this embodiment is used as a PTCA guiding catheter (inner catheter), inserted to the periphery of the left coronary artery 144, and stents 154 and 155 already placed in the left coronary artery 144. The constrictions 150 to 152 generated on the near side (base end side) and the distal side are expanded.

  In the third treatment method, a double catheter is used. The outer catheter 160 may be a conventional guiding catheter that does not include the expansion / contraction mechanism 14 and the tightening mechanism 16, or may include the expansion / contraction mechanism 14 and the tightening mechanism 16. The outer catheter 160 may have a curved shape at the distal end or may not have a curved shape, but FIG. 10 shows a curved shape. The catheter 10 of the present invention is used as an inner catheter, and the shape thereof is straight in principle, but the leading edge may be slightly bent.

  The catheter 10 is in an initial state in which the telescopic mechanism 14 is tightened by the tightening mechanism 16 so that the shaft 12 does not move in the axial direction with respect to the hub 13. When the expansion / contraction mechanism 14 is provided in the outer catheter 160, the expansion / contraction mechanism 14 is also tightened in the same manner. 7, first, the distal end of the shaft 161 of the outer catheter 160 is inserted into the blood vessel 132 from the distal opening of the sheath introducer 130, and passes through the aortic arch 138 of the aorta 136. And inserted into the ascending aorta 140.

  When the outer catheter 160 is introduced to the vicinity of the left coronary artery opening 142 of the heart 141, the guide wire 134 is operated to engage the distal end portion of the shaft 12 with the left coronary artery orifice 142, and the position of the distal end portion of the outer catheter 160 is fixed. . Note that the third treatment method can be applied to both the left and right coronary arteries, but here, a case will be described in which the stenosis 150 to 152 generated in the left coronary artery 144 is treated. This also applies to the fourth treatment method described later.

  After the distal end of the outer catheter 160 is inserted and engaged with the left coronary artery opening 142, the guide wire 134 is removed from the outer catheter 160, and a syringe is branched into the branch of the Y connector 131 attached to the rear end of the hub of the outer catheter 160. To inject contrast medium. The injected contrast medium passes through the outer catheter 160 and is ejected from the opening of the distal end into the left coronary artery 144, which is the target site. As a result, the insertion position of the distal end of the outer catheter 160 into the left coronary artery opening 142 can be confirmed, and the left coronary artery 144 can be imaged.

  Next, the catheter 10 of the present invention and the balloon catheter 146 as a treatment catheter are inserted through the rear end portion of the Y connector 131 and the lumen of the outer catheter 160. In this case, the balloon catheter 146 is inserted into the catheter 10 and the balloon 148 provided at the tip of the balloon catheter 146 is disposed in front of the catheter 10 so that the position of the balloon 148 in the catheter 10 is determined. Is fixed (held).

  Next, the position of the balloon 148 in the catheter 10 is fixed, and the catheter 10 and the balloon catheter 146 are advanced into the left coronary artery 144 with the guide wire 134 inserted through the balloon catheter 146 in advance. Then, it is inserted into the stenosis 150, which is a lesion. Then, the tightening mechanism 16 of the catheter 10 is operated to release the tightening with respect to the telescopic mechanism 14, and the shaft 12 is moved to the front side (base end side). By retracting the tip of the shaft 12 in this way, the balloon 148 is projected from the tip opening of the shaft 12. Next, the tightening mechanism 16 is operated so that the shaft 12 does not move back and forth (in the axial direction).

  Next, the stenosis 150 is treated with the balloon 148. That is, the balloon 148 is expanded to push the stenosis 150 from the inside. When the stenosis 150 is expanded, the balloon 148 is deflated. Next, after operating the tightening mechanism 16 to release the tightening of the telescopic mechanism 14, the shaft 12 is moved to the distal end side, and the balloon 148 is returned into the shaft 12. In FIG. 10, the stenosis 150 is in a state after treatment, and is indicated by a virtual line.

  As shown in FIG. 10, a stent 154 previously placed is present in the left coronary artery 144, and a stenosis 151 is formed on the distal side thereof. Therefore, the catheter 10 and the balloon catheter 146 are passed through the front stent 154 and inserted into the stenosis 151. FIG. 10 shows the situation at this time. The catheter 10 placed in the left coronary artery 144 is shown in cross-section near the tip.

  When the catheter 10 and the balloon catheter 146 are inserted into the stenosis 151, the stenosis 151 is treated in the same procedure as when the stenosis 150 is treated. When the stenosis 151 is treated, the catheter 10 and the balloon catheter 146 are inserted into the stenosis 152 via the distal stent 155 in the same procedure as described above, and the stenosis 152 is treated. After the stenosis 152 is treated, the outer catheter 160, the inner catheter (catheter 10), and the balloon catheter 146 are removed from the body.

  Next, the fourth treatment method will be described with reference to FIG. In the fourth treatment method, the stent 10 according to the present embodiment is used as a PTCA guiding catheter (inner catheter), inserted to the periphery of the left coronary artery 144, and the stent 154 previously placed in the left coronary artery 144; The stenosis 150-152 generated before and after 155 is expanded. In the fourth treatment method, when treating a plurality of stenosis portions 150 to 152 generated in the left coronary artery 144, treatment is performed from the stenosis portion 152 on the peripheral side, not from the stenosis portion 150 on the near side. This is different from the third treatment method. The outer catheter 160, the inner catheter (catheter 10), and the balloon catheter 146 used in the fourth treatment method may be the same as those used in the third treatment method.

  In the fourth treatment method, the outer catheter 160 is inserted into the blood vessel 132 through the sheath introducer 130 to reach the ascending aorta 140, and the outer catheter 160 is engaged with the left coronary artery opening 142, and then the contrast agent. Is then ejected into the left coronary artery 144, and then the balloon catheter 146 is inserted into the catheter 10, and the balloon 148 provided at the distal end of the balloon catheter 146 is disposed in front of the catheter 10 to provide a balloon. The procedure up to fixing (holding) the position of the 148 in the catheter 10 is the same as that in the third treatment method.

  Thereafter, in the fourth treatment method, the position of the balloon 148 in the catheter 10 is fixed, and the catheter 10 and the balloon catheter 146 are placed in the left coronary artery with the guide wire 134 inserted through the balloon catheter 146 in advance. The stenosis 150, 151 and the existing stents 154, 155 are passed through and inserted into the stenosis 152 located on the most distal side in the left coronary artery 144. FIG. 11 shows the situation at this time. The catheter 10 placed in the left coronary artery 144 is shown in cross-section near the tip.

  Then, the tightening mechanism 16 of the catheter 10 is operated to release the tightening with respect to the telescopic mechanism 14, and the shaft 12 is moved to the front side (base end side). By retracting the tip of the shaft 12 in this way, the balloon 148 is projected from the tip opening of the shaft 12. Next, the tightening mechanism 16 is operated so that the shaft 12 does not move back and forth (in the axial direction).

  Next, the stenosis 152 is treated with the balloon 148. That is, the balloon 148 is expanded to push the stenosis 152 from the inside. When the constriction 152 is pushed and expanded, the balloon 148 is deflated. Next, after operating the tightening mechanism 16 to release the tightening of the telescopic mechanism 14, the shaft 12 is moved to the distal end side, and the balloon 148 is returned to the most distal end portion of the shaft 12.

  Next, in a state where the balloon 148 is stored in front of the distal end portion of the shaft 12, the catheter 10 and the balloon 148 are passed through the stent 155 and pulled back into the stenosis portion 151. Then, the stenosis part 151 is treated in the same procedure as when the stenosis part 152 is treated. When the stenosis 151 is treated, the catheter 10 and the balloon catheter 146 are passed through the stent 154 and pulled back into the stenosis 150 in the same procedure as described above, and the stenosis 150 is treated. After the stenosis 150 is treated, the outer catheter 160, the inner catheter (catheter 10), and the balloon catheter 146 are removed from the body.

  The present invention is not limited to a PTCA catheter, and for example, a catheter for improving or diagnosing a lesion formed in a living organ such as a blood vessel other than the coronary artery, bile duct, trachea, esophagus, urethra, and other organs. It is also applicable to.

  In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

DESCRIPTION OF SYMBOLS 10 ... Catheter 12 ... Shaft 13 ... Hub 14, 14a-14c ... Telescopic mechanism 16, 16a ... Tightening mechanism 22 ... 1st tubular member (tubular member)
24 ... 2nd tubular member (tubular member) 26 ... 3rd tubular member (tubular member)

Claims (7)

A hollow hollow shaft having flexibility;
A hub provided on the proximal side from the shaft;
A telescopic mechanism provided between the shaft and the hub;
A tightening mechanism provided outside the expansion mechanism and configured to be capable of tightening the expansion mechanism;
The telescopic mechanism has a plurality of nested tubular members that are slidable in the axial direction with respect to each other within a restricted range.
A catheter characterized by that. The catheter of claim 1,
Outer portions of the tubular members other than those located on the outermost side among the plurality of tubular members are provided with outer concave portions or outer convex portions extending in the axial direction,
Of the plurality of tubular members, the inner peripheral portion of the tubular member other than the innermost one is provided with an inner convex portion or an inner concave portion extending in the axial direction,
The outer concave portion or the outer convex portion engages with the inner convex portion or the inner concave portion,
A catheter characterized by that. The catheter according to claim 1 or 2,
Of the plurality of tubular members, the outer peripheral portion of the tubular member other than the outermost one and the inner peripheral portion of the tubular member other than the innermost one are each provided with a rough surface.
A catheter characterized by that. The catheter according to any one of claims 1 to 3,
Each of the plurality of tubular members has an enlarged diameter part, and a proximal end reduced diameter part that is provided on the proximal end side of the enlarged diameter part and is reduced in diameter relative to the enlarged diameter part,
Among the plurality of tubular members, the tubular members other than the outermost one are, when the tubular member is located on the most distal side within the movable range, the proximal end of the proximal end reduced diameter portion of the tubular member The position extends to the vicinity or the inside of the most distal position of the proximal end reduced diameter portion of another tubular member directly surrounding the tubular member.
A catheter characterized by that. The catheter according to any one of claims 1 to 4,
The tightening mechanism is
A fastening member comprising a tubular elastic body surrounding the expansion and contraction mechanism, the inner diameter of which is reduced by being compressed in the axial direction;
A pressing member that is provided so as to be capable of changing a position in an axial direction with respect to the telescopic mechanism, and that presses the fastening member in the axial direction;
A catheter characterized by that. The catheter according to any one of claims 1 to 4,
The tightening mechanism is
A plurality of fastening members provided at intervals in the circumferential direction along the outer periphery of the telescopic mechanism;
A tubular pressing member which is provided so that the position in the axial direction can be changed with respect to the telescopic mechanism, surrounds the telescopic mechanism and the plurality of fastening members, and has a tapered inner surface formed with a diameter decreasing toward the tip. ,
A catheter characterized by that. A method for treating a stenosis in a blood vessel using a catheter,
The catheter is configured to reduce the effective length of the shaft relative to the hub;
A step of advancing the catheter and the balloon catheter into the blood vessel in a state where the balloon of the balloon catheter is disposed in the lumen at a position before the most distal end of the catheter;
Positioning the most distal portion of the catheter within the stenosis;
Retracting the distal end of the catheter by reducing the effective length of the shaft relative to the hub without changing the position of the hub of the catheter;
Positioning the balloon of the balloon catheter within the constriction.
A method for treating a stenosis in a blood vessel.

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