JP2018050722A - Catheter and method for using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter capable of exhibiting functions of a support catheter and a guiding catheter by one catheter, and a method for using the catheter.SOLUTION: A catheter 10 with a lumen for supporting a guide wire inserted into the lumen includes a tubular tip part 50 having a tip opening part 51, where the lumen opens on a distal side, a tubular intermediate part 60 provided on a proximal side of the tip part 50, and a tubular base part 70 provided on a proximal side of the intermediate part 60. An inner diameter of at least part of the tip part 50 is smaller than the smallest inner diameters of the intermediate part 60 and the base part 70, and the intermediate part 60 is more flexible than the tip part 50 and the base part 70.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a catheter inserted into a living body lumen and a method of using the same.

  A method of treating a narrowed portion of a living body lumen such as a blood vessel with a treatment device (such as a balloon catheter or a stent placement catheter) that is percutaneously inserted into the living body lumen is known. In this method, a guide wire that can penetrate the stenosis, a support catheter that supports the guide wire, and a guiding catheter that transports the treatment device to the lesion while protecting the treatment device are used (see, for example, Patent Document 1).

  The support catheter has a small clearance between the inner peripheral surface of the lumen into which the guide wire can be inserted and the guide wire. For this reason, if a guide wire is inserted in a support catheter, it will become difficult to bend a guide wire and a support catheter. Thereby, the penetration performance of the guide wire and the support catheter is enhanced, and the guide wire and the support catheter can penetrate the narrowed portion. In addition, when the clearance between the guide wire and the support catheter is large, the guide wire and the support catheter are easily bent when abutting against the stenosis, and the penetration performance is deteriorated.

  On the other hand, guiding catheters require a wide lumen to carry the treatment device. For this reason, it is difficult to use a support catheter with a narrow lumen as a guiding catheter. For example, it is difficult to pass a balloon catheter or the like, which is a treatment device, through a catheter having an inner diameter of 1.2 mm or less. Therefore, it is necessary to penetrate the guide wire through the stenosis portion using the support catheter, then remove the support catheter, and insert the guiding catheter along the guide wire to the lesioned portion.

JP 200687643 A

  As described above, in order to treat a stenosis, a support catheter that supports a guide wire and a guiding catheter that protects the treatment device and transports it to the lesion are usually required.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a catheter capable of exhibiting the functions of a support catheter and a guiding catheter and a method for using the same.

  A catheter that achieves the above-described object is a catheter having a lumen, a tubular tip provided with a tip opening that opens the lumen on the distal side, and a tubular tip provided on the proximal side of the tip An intermediate portion and a tubular base portion provided on the proximal side of the intermediate portion, wherein an inner diameter of at least a part of the tip portion is smaller than a minimum inner diameter of the intermediate portion and the base portion, and the intermediate portion is , More flexible than the tip and base.

  The catheter configured as described above is used as a support catheter by using a distal end portion having a small inner diameter, and then cuts an intermediate portion located proximal to the distal end portion and more flexible than the distal end portion and the base portion. The tip portion with a small inner diameter can be cut off. Thereby, this catheter can be used also as a guiding catheter which uses a flexible intermediate part as a tip. For this reason, the function of a support catheter and a guiding catheter can be exhibited with one catheter.

  In addition, the tip portion may have a tip taper portion whose outer diameter decreases in a taper shape toward the tip opening portion. Thereby, by pushing the catheter into the stenosis part in the living body lumen, the tip opening located on the distal side of the tip taper part is guided to the center of the stenosis part. For this reason, the guide wire can be pressed against the center of the stenosis part by projecting the guide wire from the tip opening part to the distal side through the lumen of the catheter.

  The catheter further includes a reinforcing portion that is a wire, and the reinforcing portion is positioned in a range different from a range in which the intermediate portion is provided in an axial direction of the catheter, and is positioned in a range in which the base portion is provided. May be. As a result, the intermediate portion can be cut while the rigidity of the base portion is increased by the reinforcing portion and the pushability, kink resistance, and torque transmission property in the living body lumen are enhanced. Moreover, since the reinforcement part is not located in the intermediate part, the reinforcement part is not exposed from the cut surface after the intermediate part is cut. For this reason, the damage of the biological tissue which contacts the intermediate part after cutting can be suppressed, and safety can be improved.

  The catheter further includes a reinforcing portion that is a wire, and the reinforcing portion is located in a range in which the intermediate portion and the base portion are provided in the axial direction of the catheter, As long as the base is provided, the catheter may be divided in the axial direction. Thereby, after cutting the intermediate portion, when the intermediate portion on the tip end side is separated from the base portion, the reinforcing portion that is divided and located on the distal side is removed together with the cut intermediate portion. Thereby, even if a reinforcement part is provided in an intermediate part, a reinforcement part is not exposed from the cut surface of the intermediate part connected with a base. For this reason, the damage of the biological tissue which contacts an intermediate part can be suppressed, and safety can be improved. Moreover, since the intermediate part before cutting is reinforced by the reinforcing part, the intermediate part is difficult to bend. For this reason, the function which supports the guide wire of a catheter improves.

  The intermediate portion may include an identification portion that can be visually identified. Thereby, the position to cut | disconnect can be identified easily and an appropriate position can be cut | disconnected reliably.

  The catheter may include an auxiliary portion that is located in the lumen of the intermediate portion and that can be separated from the intermediate portion and connected to the distal end portion. Thereby, since the intermediate part can be cut while supporting the intermediate part by the auxiliary part, the intermediate part can be easily cut. Moreover, since an auxiliary | assistant part supports a flexible intermediate part, an intermediate part becomes difficult to bend. For this reason, the function which supports the guide wire of a catheter improves.

  The auxiliary portion may have a groove portion extending in the circumferential direction on the outer peripheral surface. Thereby, the damage of the biological tissue which contacts an intermediate part can further be suppressed, and safety can be improved.

  Moreover, a convex part may be provided in the outer peripheral surface of the said front-end | tip part or the said intermediate part. Thereby, when inserting and using a catheter in another outer catheter, a convex part contacts the inner peripheral surface of an outer catheter. Thereby, the position of the catheter supported by the outer catheter is stabilized, and the function of supporting the guide wire by the catheter is improved.

  A method of using a catheter that achieves the above object includes the steps of: inserting a guide wire into the lumen of the catheter; supporting the guide wire at the distal end; pulling the guide wire out of the catheter; Cutting at the intermediate portion, and inserting a treatment device from the proximal side into the lumen of the catheter. The method of using the catheter configured as described above can be used for supporting the guide wire at the distal end portion and operating the guide wire, then cutting the intermediate portion and transporting the treatment device. For this reason, this catheter can be used not only for supporting a guide wire but also as a guiding catheter.

  Further, in the step of supporting the guide wire, the catheter may be inserted into another outer catheter, and the guide wire may be supported at the distal end portion while the catheter is supported by the outer catheter. Thereby, the position of the catheter supported by the outer catheter is stabilized, and the function of supporting the guide wire by the catheter is improved.

It is a top view which shows the catheter which concerns on embodiment. It is sectional drawing which shows the front-end | tip part of a catheter, (A) shows before cutting | disconnection, (B) shows after cutting | disconnection. It is sectional drawing which shows the state which inserted the catheter in the blood vessel, (A) shows the state which inserted the guide wire in the blood vessel, (B) shows the state which inserted the catheter in the blood vessel along the guide wire. It is sectional drawing which shows the state which inserted the catheter in the blood vessel, (A) is the state which pushed the guide wire supported by the catheter into the stenosis part, (B) inserted the catheter which cut | disconnected the intermediate part in the blood vessel. Indicates the state. It is sectional drawing which shows the state which inserted the catheter in the blood vessel, (A) is the state which inserted the balloon catheter into the blood vessel through the lumen | bore of a catheter, (B) is the state which expanded the stenosis part by the balloon catheter. Show. It is sectional drawing which shows the front-end | tip part of the catheter which is a modification, (A) is a 1st modification, (B) is a 2nd modification, (C) is a 3rd modification, (D) is a 1st modification. 4 shows a modification. It is sectional drawing which shows the front-end | tip part of the catheter which is a 5th modification, (A) is the state before cut | disconnecting an intermediate part, (B) is the state after cut | disconnecting an intermediate part, (C) cut | disconnected The state which removed the site | part is shown. It is sectional drawing which shows the front-end | tip part of the catheter which is a modification, (A) is a 6th modification, (B) is a 7th modification. It is sectional drawing which shows the front-end | tip part of the catheter which is an 8th modification, (A) shows the state before cut | disconnecting an intermediate part, (B) shows the state after cut | disconnecting an intermediate part. It is sectional drawing which shows the front-end | tip part of the catheter which is a 9th modification.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio. In the following description, the proximal side of the catheter is referred to as “proximal side”, and the side inserted into the living body is referred to as “distal side”.

  The catheter 10 according to this embodiment has a function as a support catheter for supporting a guide wire and a function as a guiding catheter for carrying a treatment device to a lesioned part. The support catheter is a catheter for supporting a guide wire penetrating through a stenosis (including an occlusion) in a blood vessel (biological lumen). A guiding catheter is a catheter for carrying a treatment device to a lesion. The treatment device is not particularly limited, and is, for example, a balloon catheter or a stent delivery catheter for expanding and maintaining the diameter of the stenotic part by delivering a contracted stent to the stenotic part.

  As shown in FIGS. 1 and 2, the catheter 10 includes a tubular catheter body 20, a linear shaft 30 located on the proximal side of the catheter body 20, and a gripping portion 40 located on the proximal side of the shaft 30. It has. The catheter 10 is a rapid exchange type catheter 10. The catheter 10 is used in combination with an outer catheter 80 which is a general guiding catheter. The outer catheter 80 includes a tubular outer catheter body 81, an outer catheter hub 82 located on the proximal side of the outer catheter body 81, and a tip tip 83 located on the distal side of the outer catheter body 81. The outer catheter body 81 has a lumen into which the catheter body 20 can be inserted.

  The gripping unit 40 is a part that is located outside the body during the procedure and is operated by being gripped by the operator. By grasping and operating the grasping portion 40, the catheter 10 inserted into the blood vessel can be advanced and retracted along the axial center, or rotated around the axial center.

  The shaft 30 is a part that connects the grip portion 40 and the catheter body 20. The shaft 30 transmits a force acting on the grip portion 40 to the catheter body 20. The distal end portion of the shaft 30 is fixed to the outer peripheral surface of the proximal end portion of the catheter body 20. The constituent material of the shaft 30 is, for example, a metal such as stainless steel or NiTi alloy.

  The catheter body 20 is a long tube having flexibility. The catheter body 20 is provided with a lumen 21 (lumen) over the entire length of the catheter body 20 at substantially the center thereof. The catheter body 20 includes a distal end portion 50 located on the distal side, an intermediate portion 60, and a base portion 70.

  The tip 50 is located on the most distal side of the catheter body 20. The distal end portion 50 is a tubular portion that supports a guide wire inserted into the lumen 21. The tip 50 is provided with a tip opening 51 where the lumen 21 is opened on the distal side. The tip portion 50 has a tip taper portion 52 on the outer peripheral surface on the distal side. The tip tapered portion 52 has an outer diameter that decreases in a tapered manner toward the distal side. The tip opening 51 opens at the most distal portion of the tip taper portion 52. The tip portion 50 has a first inner peripheral surface 53 and a second inner peripheral surface 54. The first inner peripheral surface 53 has a constant inner diameter in the axial direction and communicates with the tip opening 51. The second inner peripheral surface 54 is located on the proximal side of the first inner peripheral surface 53. The inner diameter of the second inner peripheral surface 54 decreases in a tapered manner toward the distal side, and coincides with the inner diameter of the first inner peripheral surface 53 at a position continuous with the first inner peripheral surface 53. The clearance between the first inner peripheral surface 53 and the inserted guide wire is small. For this reason, the 1st inner peripheral surface 53 can support a guide wire so that it may not bend. Since the second inner peripheral surface 54 is tapered, it is easy to insert a guide wire therein.

  Although the inclination angle with respect to the central axis of the tip tapered portion 52 is appropriately set, it is, for example, 30 to 60 degrees. The length in the axial direction of the tip 50 is appropriately set, and is, for example, 3 to 10 mm.

  Although the internal diameter of the 1st internal peripheral surface 53 is suitably set with the outer diameter of the guide wire to be used, it is 0.5-1.0 mm, for example. Although the clearance between the 1st internal peripheral surface 53 and the guide wire inserted is suitably set, it is 0.05-0.15 mm, for example.

  The constituent material of the distal end portion 50 preferably has rigidity capable of supporting the guide wire. For example, styrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, transpolyisoprene, fluororubber, chlorine Various thermoplastic elastomers such as a modified polyethylene type are mentioned, and one (or a combination of two or more of these) (polymer alloy, polymer blend, laminate, etc.) is preferred.

  The intermediate part 60 is a tubular part provided on the proximal side of the tip part 50. The intermediate part 60 has a constant inner diameter and outer diameter. The inner diameter of the third inner peripheral surface 61 inside the intermediate portion 60 matches the inner diameter on the proximal side of the second inner peripheral surface 54. The inner diameter of the third inner peripheral surface 61 is larger than the inner diameter of the first inner peripheral surface 53.

  The intermediate part 60 is made of a material softer than the tip part 50 and the base part 70. The hardness of the material is, for example, Shore A hardness or Shore D hardness of a durometer test measured according to ISO868. For this reason, the intermediate part 60 is a surface substantially orthogonal to the central axis and can be cut more easily than the base part 70 (see FIG. 2B). Further, since the intermediate portion 60 is flexible, it does not damage the living tissue that comes into contact with the intermediate portion 60 after being cut. An identification portion 62 (see the shaded portion in FIG. 1) is provided on the outer peripheral surface of the intermediate portion 60 so as to make it possible to visually recognize a severable position. The identification unit 62 is displayed in a color different from the surroundings, for example. Although the identification part 62 may be provided in the whole outer peripheral surface of the intermediate part 60, it may be provided in a part. In addition, when the intermediate part 60 is cut | disconnected, the site | part connected with the base 70 needs to remain partially. The portion that remains connected to the base portion 70 of the intermediate portion 60 is a tip that flexibly contacts the living tissue. For this reason, the identification part 62 does not need to be provided on the outer surface on the proximal side of the intermediate part 60. Thereby, after cutting | disconnecting, the site | part connected with the base 70 of the intermediate part 60 can be left reliably. The identification part may not be a color different from the surroundings as long as it is visible. For example, the identification part may have a visually recognizable shape such as a groove or a recess. If the identification part is a groove provided on the outer peripheral surface over 360 degrees, it is easy to guide the blade and cut easily.

  Although the outer diameter of the intermediate part 60 is set suitably, it is 1.3-2.0 mm, for example. Although the internal diameter of the intermediate part 60 is set suitably, it is 1.2-1.8 mm, for example. The axial length of the intermediate portion 60 is appropriately set, but is preferably 1 to 20 mm, more preferably 3 to 8 mm, and still more preferably 4 to 6 mm. If the intermediate portion 60 is too long, the catheter main body 20 is easily bent at the intermediate portion 60, and the function as a support catheter is reduced. If the intermediate part 60 is too short, cutting becomes difficult. Moreover, when the intermediate part 60 is too short, the front-end | tip chip | tip after a cutting | disconnection will become short, and it will become easy to damage the biological tissue which contacts.

  It is preferable that the constituent material of the intermediate portion 60 is a material that is easy to cut and rich in flexibility so that the living tissue that comes into contact with the intermediate portion 60 is not damaged. The constituent material of the intermediate part 60 is, for example, various rubber materials such as natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, silicone rubber, fluorine rubber, styrene-butadiene rubber, styrene, polyolefin, polyurethane, polyester. Various thermoplastic elastomers such as polyamide, polybutadiene, trans polyisoprene, fluororubber, and chlorinated polyethylene are suitable.

  The intermediate portion 60 may include a radiopaque material (X-ray contrast agent) in the constituent material. By including the radiopaque material, the position can be confirmed under fluoroscopy. Examples of the radiopaque material include barium sulfate, bismuth oxide, and tungsten. The ratio which mix | blends a radiopaque material in a structural material is 30-80 wt%, for example.

  The base part 70 is a tubular part provided on the proximal side of the intermediate part 60. The base 70 includes a proximal end opening 71 through which the lumen 21 opens at the proximal end surface. The base 70 has a constant inner diameter and outer diameter. The inner diameter and outer diameter of the base portion 70 coincide with the inner diameter and outer diameter of the intermediate portion 60. The inner diameter of the fourth inner peripheral surface 72 inside the base portion 70 is larger than the inner diameter of the first inner peripheral surface 53. Note that the inner diameter of the base portion 70 may not coincide with the inner diameter of the intermediate portion 60. Further, the outer diameter of the base portion 70 may not match the outer diameter of the intermediate portion 60. For example, the inner and outer diameters of the base 70 may decrease toward the distal side. The base 70 includes an inner layer 73, an outer layer 74, and a reinforcing portion 75. The inner layer 73 includes a fourth inner peripheral surface 72 that forms the lumen 21. The outer layer 74 is provided outside the inner layer 73 and coaxially with the inner layer 73. The reinforcing portion 75 is located between the inner layer 73 and the outer layer 74.

  The constituent material of the inner layer 73 is preferably a low-friction material so that a medical device such as a treatment device or a guide wire can be easily moved within the lumen 21. For this reason, the passability of the medical instrument is improved, and the operability is improved. Examples of the low friction material constituting the inner layer 73 include fluorine resin materials such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene / ethylene copolymer (ETFE). The constituent material of the inner layer 73 is not limited to the low friction material, and various resin materials can be applied.

  The constituent material of the outer layer 74 is preferably flexible, for example, styrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, trans polyisoprene, fluororubber, chlorinated polyethylene, etc. These thermoplastic elastomers and the like can be mentioned, and one of these or a combination of two or more thereof (polymer alloy, polymer blend, laminate, etc.) can be used.

  The reinforcing portion 75 is a portion that reinforces the base portion 70. The reinforcing part 75 has a plurality of reinforcing wires. The material of the outer layer 74 or the inner layer 73 enters the gaps between the plurality of reinforcing wires in the reinforcing portion 75. For example, the reinforcing portion 75 is formed by forming a reinforcing wire in a spiral shape or a net shape. The constituent material of the reinforcing wire is, for example, a metal such as stainless steel or NiTi alloy, or a resin. The reinforcing wire is, for example, a flat plate obtained by crushing a wire rod into a flat plate shape. If the reinforcing wire is a flat plate, the radial thickness of the base portion 70 can be reduced. In addition, a reinforcement wire is not limited to a flat wire, For example, a round wire and an ellipse may be sufficient. Each reinforcing wire may be a bundle of two or more reinforcing wires.

  Note that the number of layers constituting the base portion 70, the constituent materials of each layer, the presence / absence of reinforcing wires, and the like may vary along the axial direction of the base portion 70. Further, the base portion 70 may not have the reinforcing portion 75. Moreover, the front-end | tip part 50 and the intermediate part 60 may also be comprised by multiple layers.

  The catheter body 20 may be at least partially curved. When the catheter body 20 is curved, the direction of pushing can be selected by rotating. Thereby, the passability in the blood vessel which curves is improved. Further, when the catheter body 20 is curved, it is easy to engage (engage) with the wall surface of the blood vessel.

  Next, a method of using the catheter 10 according to the present embodiment will be described by taking as an example a case where the stenotic portion N in the blood vessel is pushed out by the balloon catheter 100 (treatment device). The catheter 10 is used together with an outer catheter 80 into which the catheter 10 can be inserted. The catheter 10 may not be used with the outer catheter 80.

  First, an introducer sheath (not shown) is inserted percutaneously into a blood vessel, and a guide wire 90 is inserted into the blood vessel through the introducer sheath as shown in FIG. Next, the guide wire 90 is pushed forward to reach the constriction N.

  Next, the catheter 10 is inserted and penetrated into the outer catheter 80. Next, the proximal end portion of the guide wire 90 located outside the body is inserted into the lumen 21 from the distal end opening portion 51 of the catheter 10. Subsequently, along the guide wire 90, the catheter 10 is moved in the distal direction together with the outer catheter 80, and inserted into the blood vessel via the introducer sheath. Thereafter, the catheter 10 is pushed forward together with the outer catheter 80 to reach the vicinity of the stenosis N as shown in FIG. If the intermediate part 60 includes a radiopaque material, the position of the intermediate part 60 can be easily confirmed under fluoroscopy.

  Next, the handle 40 is operated to move the catheter 10 in the distal direction. Thereby, the tip tapered portion 52 is pushed into the narrowed portion N. Thereby, the tip opening 51 that opens at the most distal side of the tapered tip tapered portion 52 is positioned at the center of the blood vessel lumen (center of the stenosis N). Next, the guide wire 90 is pushed in the distal direction while maintaining the catheter 10 in this state. As a result, as shown in FIG. 4A, the guide wire 90 protrudes from the distal end opening 51 positioned at the center of the narrowed portion N and can be pressed against the center of the narrowed portion N. Thereafter, the guide wire 90 is further pushed in the distal direction. At this time, the distal end portion 50 is harder than the intermediate portion 60 and the clearance between the first inner peripheral surface 53 of the distal end portion 50 and the guide wire 90 is small, so the guide wire 90 is difficult to bend and the pushing force is difficult to escape. . Further, since the guide wire 90 is supported by the catheter 10 supported by the outer catheter 80, the guide wire 90 is further difficult to bend and the pushing force is difficult to escape. For this reason, it is possible to satisfactorily transmit a pushing force sufficient to pass through the narrowed portion N from the hand to the distal end portion 50 of the guide wire 90. Therefore, the guide wire 90 can easily penetrate the narrowed portion N. Thus, the catheter 10 functions as a support catheter that supports the guide wire 90.

  After the guide wire 90 penetrates the stenosis N, the catheter 10 is pulled out from the outer catheter 80 leaving the guide wire 90. Thereby, the catheter 10 is located outside the body. Next, as shown in FIG. 2B, the intermediate portion 60 is cut in a cross section intersecting with the central axis by cutting means such as scissors, a knife, a knife, or a heating wire. Since the identification part 62 is provided in the outer surface of the intermediate part 60 at this time, the suitable position of the intermediate part 60 can be cut | disconnected easily. As a result, the catheter body 20 is in a state in which a part of the flexible intermediate portion 60 is connected to the distal side of the base portion 70. A portion of the tip 50 and the intermediate portion 60 distal to the cutting plane is discarded. As a result, the distal end portion 50 having a small inner diameter is removed from the catheter body 20.

  Next, the proximal end portion of the guide wire 90 located outside the body is inserted into the lumen 21 of the catheter 10. Next, the catheter 10 is inserted into the outer catheter 80 along the guide wire 90. Subsequently, the catheter 10 is moved in the distal direction to reach the vicinity of the stenosis N as shown in FIG. At this time, the intermediate portion 60 located on the most distal side of the catheter 10 is made of a material that is more flexible than the distal end portion 50 and the base portion 70. For this reason, even if the catheter 10 is pushed forward in a curved, bent, or branched blood vessel, the flexible intermediate portion 60 contacts the blood vessel. For this reason, the catheter 10 can be moved smoothly and safely in the blood vessel. Moreover, if the intermediate part 60 contains a radiopaque material, the position of the intermediate part 60 can be easily confirmed under X-ray fluoroscopy.

  Next, the balloon catheter 100 is inserted from the proximal end opening of the outer catheter 80. Subsequently, the balloon catheter 100 is inserted into the lumen 21 from the proximal end opening 71 of the catheter body 20 located in the lumen of the outer catheter 80. At this time, the catheter 10 functions as a guiding catheter. Therefore, the catheter 10 can easily guide the balloon catheter 100 to the vicinity of the stenosis N through the lumen 21. Since the distal end 50 having a small inner diameter is removed from the catheter 10, the balloon catheter 100 can be led out into the blood vessel from the opening on the distal side of the lumen 21. Thereafter, the balloon catheter 100 is inserted into the stenosis N as shown in FIG. Thereafter, as shown in FIG. 5B, the balloon 101 can be expanded to push the stenosis N.

  Next, the balloon 101 is deflated. Subsequently, the balloon 101 is drawn into the lumen 21 of the catheter 10, moved to the proximal side, and removed from the blood vessel. Thereafter, the catheter 10 is withdrawn from the blood vessel, and the treatment is completed.

  As described above, the catheter 10 according to the present embodiment is a catheter 10 having a lumen, and includes a tubular distal end portion 50 including a distal end opening 51 having a lumen opened on a distal side, and the distal end portion 50. It has a tubular intermediate part 60 provided on the proximal side and a tubular base part 70 provided on the proximal side of the intermediate part 60, and the inner diameter of at least a part of the tip part 50 is the intermediate part 60 and the base part 70. The intermediate portion 60 is more flexible than the distal end portion 50 and the base portion 70. The catheter 10 configured as described above is used as a support catheter using the distal end portion 50 having a small inner diameter, and then cuts the intermediate portion 60 that is located on the proximal side of the distal end portion 50 and is more flexible than the base portion 70. Thus, the tip 50 having a small inner diameter can be cut off. Thereby, this catheter 10 can be used also as a guiding catheter which conveys the device for treatment. For this reason, this catheter 10 can demonstrate the function of a support catheter and a guiding catheter by one. By the way, the catheter 10 is a rapid exchange type, and it is harder to apply a pushing force than the over-the-wire type. However, by adopting the rapid exchange type, insertion into and removal from the blood vessel is facilitated, and cutting at the intermediate portion 60 is easy.

  The tip 50 has a tip tapered portion 52 whose outer diameter decreases in a tapered manner toward the tip opening 51. Thereby, when the catheter 10 is pushed into the stenosis N in the living body lumen, the tip opening 51 located on the distal side of the tip taper 52 is guided to the center of the stenosis N. For this reason, the guide wire 90 can be pressed against the center of the stenosis N by projecting the guide wire 90 distally from the distal end opening 51 through the lumen of the catheter 10.

  The catheter 10 further includes a reinforcing portion 75 that is a wire, and the reinforcing portion 75 is located in a range different from the range in which the intermediate portion 60 is provided in the axial direction of the catheter 10 and the base portion 70 is provided. Located in range. Thus, the intermediate portion 60 can be cut while the rigidity of the base portion 70 is increased by the reinforcing portion 75 to improve pushability, kink resistance, and torque transmission in the blood vessel. Moreover, since the reinforcement part 75 is not located in the intermediate part 60, the reinforcement part 75 is not exposed from the cut surface after cutting the intermediate part 60. For this reason, the damage of the biological tissue which contacts the intermediate part 60 after cutting can be suppressed, and safety can be improved.

  The intermediate unit 60 includes an identification unit 62 that can be identified visually. Thereby, the position to cut | disconnect can be identified easily and an appropriate position can be cut | disconnected reliably.

  Further, the method of using the catheter 10 includes a step of inserting the guide wire 90 into the lumen of the catheter 10 and supporting the guide wire 90 by the distal end portion 50, a step of pulling out the guide wire 90 from the catheter 10, and a catheter 10 Cutting at the intermediate portion 60 and inserting a treatment device into the lumen of the catheter 10 from the proximal side. The method of using the catheter 10 configured as described above is to use the guide wire 90 by supporting the guide wire 90 with the distal end portion 50 and operating the guide wire 90, then cutting the intermediate portion 60 and transporting the treatment device. Can do. For this reason, this catheter 10 can be used not only for supporting the guide wire 90 but also as a guiding catheter.

  Further, in the step of supporting the guide wire 90, the catheter 10 may be inserted into another outer catheter 80, and the guide wire 90 may be supported by the distal end portion 50 while the catheter 10 is supported by the outer catheter 80. Thereby, the position of the catheter 10 supported by the outer catheter 80 is stabilized, and the function of supporting the guide wire 90 by the catheter 10 is improved. For this reason, the high pushing force with respect to the constriction N of the guide wire 90 can be obtained.

  The present invention also includes a treatment method (therapeutic method) using the catheter 10 described above. In the treatment method, the guide wire 90 is inserted into the lumen of the catheter 10 in the living body lumen, and the guide wire 90 is pressed against the constricted portion N in the living body lumen while the guide wire 90 is pressed against the narrowed portion N in the living body lumen. N, pushing the catheter 10 out of the body lumen, cutting the catheter 10 at the intermediate portion 60, inserting the catheter 10 into the body lumen, and approaching the lumen of the catheter 10 Inserting a treatment device from the distal side. The treatment method configured as described above can be used to cut the intermediate portion 60 of the catheter 10 used to push the guide wire 90 into the stenosis N and to transport the catheter 10 to the treatment device. For this reason, this treatment method can support the guide wire 90 and transport the treatment device with a single catheter 10.

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical idea of the present invention.

  For example, as in the first modification shown in FIG. 6A, the first inner peripheral surface 111 having a small inner diameter of the tip portion 110 may be located over the entire tip portion 110. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as the above-mentioned embodiment, and description is abbreviate | omitted. Thereby, the range which supports the guide wire 90 of the front-end | tip part 110 spreads, and the function as a support catheter improves. The second inner peripheral surface 121 whose inner diameter decreases in a tapered shape toward the distal side is located in the intermediate portion 120. As described above, the inner diameter on the distal side of the intermediate part 120 may be smaller than the inner diameter on the proximal side of the intermediate part 120.

  Further, as in the second modification shown in FIG. 6B, the outer peripheral surface 131 and the inner peripheral surface 132 of the distal end portion 130 may be curved surfaces that protrude outward in the radial direction of the catheter. Thereby, the position where the first inner peripheral surface 53 of the distal end portion 130 is provided becomes thick, and the guide wire 90 can be firmly supported. For this reason, the function which supports the guide wire 90 as a support catheter improves. For this reason, the high pushing force with respect to the constriction N of the guide wire 90 can be obtained. Moreover, since the outer peripheral surface 131 of the front-end | tip part 130 becomes smooth, damage to a biological tissue can be suppressed and safety | security improves.

  Further, as in the third modification shown in FIG. 6C, the most distal portion of the tip portion 140 may be a cylinder having a constant inner diameter and outer diameter. Thereby, the range where an outer diameter is constant is provided in the position where the front-end | tip opening part 51 is provided. Therefore, the length capable of supporting the guide wire 90 (the length in the axial direction of the first inner peripheral surface 141) can be arbitrarily set, and the degree of freedom in design is improved.

  In addition, as in the fourth modification shown in FIG. 6D, the distal end portion 150 has a first inner peripheral surface 151 that is a portion having the smallest inner diameter, even if the first inner peripheral surface 151 does not have a length in the axial direction of the catheter. Good. Further, the inclination angle of the tapered second inner peripheral surface 152 may be different from the inclination angle of the outer peripheral surface 153.

  Further, as in the fifth modified example shown in FIG. 7A, an auxiliary portion 160 that is not connected to the intermediate portion 60 may be provided in the lumen of the intermediate portion 60. The auxiliary portion 160 has a substantially cylindrical shape, and a distal end portion is fixed to the tip portion 170 by fusion or adhesion. On the outer peripheral surface of the auxiliary portion 160, a groove portion 161 is provided in the circumferential direction over 360 degrees. An identification portion 62 is preferably provided at a position corresponding to the groove 161 on the outer peripheral surface of the intermediate portion 60 so that the position of the groove 161 can be visually identified. Since the auxiliary portion 160 supports the flexible intermediate portion 60, the intermediate portion 60 is difficult to bend. For this reason, the function as a support catheter which supports the guide wire 90 improves. When cutting the intermediate portion 60, as shown in FIG. 7B, the intermediate portion 60 can be cut while the intermediate portion 60 is supported by the auxiliary portion 160. Therefore, the intermediate portion 60 is difficult to escape due to the pressing force of the blade. It becomes easy to cut. Moreover, since the intermediate part 60 can be cut | disconnected along the groove part 161, it can cut | disconnect reliably in a suitable position. Further, when the intermediate portion 60 is cut, the intermediate portion 60 enters the groove portion 161 and the outer edge of the cut surface of the intermediate portion 60 is not sharp. For this reason, the damage of the biological tissue which contacts the intermediate part 60 can further be suppressed, and safety can be improved. The auxiliary part 160 is not connected to the intermediate part 60 and can be separated from the intermediate part 60. For this reason, after cutting the intermediate part 60, as shown in FIG.7 (C), the front-end | tip part 170 can be removed. In FIG. 7A, the outer peripheral surface of the auxiliary portion 160 is not in contact with the inner peripheral surface of the intermediate portion 60, but may be in contact. When the auxiliary part 160 contacts the intermediate part 60, the flexible intermediate part 60 can be supported more strongly, and the function as a support catheter for supporting the guide wire 90 is improved. In addition, in FIG. 6, the shape of the groove part 161 is an acute angle in the depth direction in the cross section which passes along the center axis | shaft of the catheter 10 so that the blade to cut | disconnect can follow easily. However, the shape of the groove is not limited to this. Therefore, the edge 162 of the groove 161 may be formed with a smooth curved surface.

  Further, as in the sixth modification shown in FIG. 8A, the intermediate portion 180 may be more flexible than the base portion 70 by being thinner than the base portion 70. In this case, the constituent material of the intermediate portion 180 may be the same as that of the base portion 70. That is, the intermediate portion 180 may be structurally flexible instead of being flexible depending on the constituent material.

  Further, as in the seventh modified example shown in FIG. 8B, the intermediate portion 190 may have the same inner layer 73 and outer layer 74 as the base portion 70. The intermediate portion 190 can be made more flexible than the base portion 70 because the reinforcing portion 75 is not provided.

  Further, as in the eighth modification shown in FIG. 9A, the reinforcing portion 200 may be located in a range in which the intermediate portion 60 is provided and a range in which the base portion 70 is provided in the axial direction of the catheter 10. . The reinforcing portion 200 may or may not be located in the range where the distal end portion 50 is provided in the axial direction of the catheter 10. Each wire rod of the reinforcing portion 200 is divided (cut) in the axial direction of the catheter 10 at a dividing section D located in a range where the base portion 70 is provided. As a result, after the intermediate portion 60 is cut, when the intermediate portion 60 on the distal end portion 50 side is separated from the base portion 70, as shown in FIG. The reinforcing part 200 </ b> A located at is removed. Thereby, even if the reinforcement part 200 is provided in the intermediate part 60, a wire is not exposed from the cut surface of the intermediate part 60 connected with the base 70. FIG. For this reason, the damage of the biological tissue which contacts the intermediate part 60 can be suppressed, and safety can be improved. Moreover, since the intermediate part 60 before cutting is reinforced by the reinforcing part 200, the intermediate part 60 is difficult to bend. Thereby, the function as a support catheter which supports the guide wire 90 improves. When the intermediate portion 60 is cut, a portion of the intermediate portion 60 closer to the inner peripheral surface than the reinforcing portion 200 does not pass the blade and is difficult to cut. However, since the intermediate portion 60 is flexible, the cut surface develops from the cut portion, and the entire intermediate portion 60 can be cut. Alternatively, a cut for promoting cutting may be provided over 360 degrees or partially on the inner side (inner peripheral surface side) of the reinforcing portion 200 of the intermediate portion 60. In addition, the reinforcement part located in the intermediate part 60 may be a wire extending linearly in the axial direction, for example, so as to be easily pulled out. Therefore, the reinforcing part located in the intermediate part 60 may have a different structure from the reinforcing part located in the base part 70.

  Further, as in the ninth modified example shown in FIG. 10, a convex portion 211 that protrudes radially outward may be provided on the outer peripheral surface of the tip portion 210. Although the convex part 211 is provided over 360 degree | times in the circumferential direction of an outer peripheral surface, you may provide partially. Accordingly, when the catheter 10 is inserted into another outer catheter 80 and used, the convex portion 211 comes into contact with the inner peripheral surface of the outer catheter 80. For this reason, when the guide wire 90 inserted into the lumen 21 is pushed in, the catheter 10 is inserted into the lumen of another outer catheter 80, and the guide wire 90 is inserted into the constriction N while the catheter 10 is supported by the outer catheter 80. Can be pushed in. Thereby, the position of the catheter 10 supported by the outer catheter 80 is stabilized, and the function of supporting the guide wire 90 by the catheter 10 is improved. In addition, the convex part 211 of the outer peripheral surface of the catheter 10 may be located not in the tip part but in an intermediate part.

  The use of the catheter 10 is not particularly limited as long as it is inserted into a living body lumen and used. The living body lumen is not limited to a blood vessel, and may be, for example, a blood vessel, a ureter, a bile duct, a fallopian tube, a hepatic tube, or the like.

  Further, the catheter may be an over the wire type catheter.

  Further, the distal end face provided with the distal end opening of the catheter body may be a flat plane without protruding in a tapered shape.

10 catheter,
20 catheter body,
21 lumens (lumen),
50, 110, 130, 140, 150, 170, 210 tip,
51 Tip opening,
52 Tapered end,
60, 120, 180, 190 middle part,
62 Identification part,
70 base,
71 proximal opening,
75, 200 reinforcement part,
80 external catheter,
90 guide wire,
100 balloon catheter (treatment device),
160 auxiliary part,
161 groove,
211 convex part,
N Stenosis.

Claims (10)

A catheter having a lumen and supporting a guide wire inserted into the lumen,
A tubular tip having a tip opening that opens distally to the lumen;
A tubular intermediate portion provided on the proximal side of the tip portion;
A tubular base provided on the proximal side of the intermediate portion,
An inner diameter of at least a part of the distal end portion is smaller than a minimum inner diameter of the intermediate portion and the base portion, and the intermediate portion is more flexible than the distal end portion and the base portion.   The catheter according to claim 1, wherein the distal end portion has a distal tapered portion whose outer diameter decreases in a tapered shape toward the distal end opening. It further has a reinforcing part that is a wire,
The catheter according to claim 1, wherein the reinforcing portion is located in a range different from a range in which the intermediate portion is provided and in a range in which the base portion is provided in the axial direction of the catheter. It further has a reinforcing part that is a wire,
The reinforcing portion is located in a range in which the intermediate portion is provided and a range in which the base portion is provided in the axial direction of the catheter,
The catheter according to claim 1 or 2, wherein the reinforcing portion is divided in an axial direction of the catheter within a range in which the base portion is provided.   The catheter according to any one of claims 1 to 4, wherein the intermediate portion includes an identification portion that can be visually identified.   The catheter according to any one of claims 1 to 5, further comprising an auxiliary portion that is located in a lumen of the intermediate portion and that can be separated from the intermediate portion and connected to the distal end portion.   The catheter according to claim 6, wherein the auxiliary portion has a groove portion extending in a circumferential direction on an outer peripheral surface.   The catheter of any one of Claims 1-7 by which a convex part is provided in the outer peripheral surface of the said front-end | tip part or an intermediate part. A method of using the catheter according to claim 1,
Inserting a guide wire into the lumen of the catheter and supporting the guide wire at the tip;
Withdrawing the guidewire from the catheter;
Cutting the catheter at the intermediate portion;
Inserting a treatment device proximally into the lumen of the catheter.   The method of using a catheter according to claim 9, wherein in the step of supporting the guide wire, the catheter is inserted into another outer catheter, and the guide wire is supported at the distal end portion while the catheter is supported by the outer catheter. .

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