JP6792392B2 - catheter - Google Patents

Description

The present invention relates to catheters for insertion into a body lumen.

A method of treating a narrowed portion of a biological lumen such as a blood vessel with a treatment device (balloon catheter, stent placement catheter, etc.) that is percutaneously inserted into the biological lumen is known. This method uses a guide wire that can penetrate the stenosis, a support catheter that supports the guide wire, and a guiding catheter that protects the treatment device and carries it to the lesion (see, for example, Patent Document 1).

The support catheter has a small clearance between the inner peripheral surface of the cavity into which the guide wire can be inserted and the guide wire. Therefore, when the guide wire is inserted into the support catheter, the guide wire and the support catheter are less likely to bend. As a result, the guide wire and the support catheter have improved penetration performance and can penetrate the narrowed portion. If the clearance between the guide wire and the support catheter is large, the guide wire and the support catheter tend to bend when abutted against the narrowed portion, and the penetration performance deteriorates.

Guiding catheters, on the other hand, require a large 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 use the support catheter to penetrate the guide wire through the stenosis, then remove the support catheter and insert the guiding catheter along the guide wire to the lesion.

Japanese Unexamined Patent Publication No. 2006-87643

As mentioned above, treating a stenosis usually requires a support catheter to support the guidewire and a guiding catheter to carry the treatment device to the lesion while protecting it.

The present invention has been made to solve the above problems, and an object thereof is to provide a catheters can exhibit support catheter and guiding catheter functions in one.

The catheter that achieves the above object is a catheter having a lumen, which has a tubular tip having a tip opening at which the lumen opens on the distal side and a tubular tip provided on the proximal side of the tip. It has an intermediate portion and a tubular base portion provided on the proximal side of the intermediate portion, and the inner diameter of at least a part of the tip portion is smaller than the minimum inner diameter of the intermediate portion and the base portion, and the intermediate portion is , Ri flexible der than the tip portion and base portion, said middle portion, that have a discrimination unit that can be identified visually.

The catheter constructed as described above is used as a support catheter by utilizing the tip having a small inner diameter, and then the middle part located on the proximal side of the tip and more flexible than the tip and the base is cut. , The tip with a small inner diameter can be separated. As a result, this catheter can also be used as a guiding catheter with a flexible intermediate tip as the tip. Therefore, the catheter can perform the function of the support catheter and guiding catheters with a single.
Further, the intermediate portion has an identification portion that can be visually identified. As a result, the cutting position can be easily identified, and an appropriate position can be reliably cut.
The proximal end of the identification may be provided distal to the connection between the intermediate and the base.

Further, the tip portion may have a tip tapered portion whose outer diameter decreases in a tapered shape toward the tip opening. As a result, by pushing the catheter into the stenosis in the living lumen, the tip opening located on the distal side of the tip taper is guided to the center of the stenosis. Therefore, the guide wire can be pressed against the center of the stenosis by projecting the guide wire from the tip opening to the distal side through the lumen of the catheter.

Further, the catheter further has a reinforcing portion that is a wire rod, and the reinforcing portion is located in a range different from the range in which the intermediate portion is provided in the axial direction of the catheter, and is located in a range in which the base portion is provided. You may. As a result, the rigidity of the base portion can be increased by the reinforcing portion to improve the pushability, kink resistance, and torque transmission in the living lumen, and the intermediate portion can be cut. Further, since the reinforcing portion is not located in the intermediate portion, the reinforcing portion is not exposed from the cut surface after cutting the intermediate portion. Therefore, damage to the living tissue in contact with the intermediate portion after cutting can be suppressed, and safety can be enhanced.

Further, the catheter further has a reinforcing portion which is a wire rod, and the reinforcing portion is located in a range where the intermediate portion is provided and a range where the base portion is provided in the axial direction of the catheter. , The catheter may be divided in the axial direction within the range in which the base is provided. As a result, when the intermediate portion on the tip end side is separated from the base portion after cutting the intermediate portion, the reinforcing portion that is divided and located on the distal side is removed together with the cut intermediate portion. As a result, even if the reinforcing portion is provided in the intermediate portion, the reinforcing portion is not exposed from the cut surface of the intermediate portion connected to the base portion. Therefore, damage to the living tissue in contact with the intermediate portion can be suppressed, and safety can be enhanced. Further, since the intermediate portion before cutting is reinforced by the reinforcing portion, the intermediate portion is less likely to bend. Therefore, the function of supporting the guide wire of the catheter is improved.

In addition, the catheter may have an auxiliary portion that is located in the lumen of the intermediate portion and can be separated from the intermediate portion and is connected to the tip portion. As a result, the intermediate portion can be cut while the intermediate portion is supported by the auxiliary portion, so that the intermediate portion can be easily cut. Further, since the auxiliary portion supports the flexible intermediate portion, the intermediate portion is less likely to bend. Therefore, the function of supporting the guide wire of the catheter is improved.

Further, the auxiliary portion may have a groove portion extending in the circumferential direction on the outer peripheral surface. As a result, damage to the living tissue in contact with the intermediate portion can be further suppressed, and safety can be enhanced.

Further, a convex portion may be provided on the outer peripheral surface of the tip portion or the intermediate portion. As a result, when the catheter is inserted into another outer catheter and used, the convex portion comes into contact with the inner peripheral surface of the outer catheter. This stabilizes the position of the catheter supported by the external catheter and improves the ability of the catheter to support the guide wire.

It is a top view which shows the catheter which concerns on embodiment. It is sectional drawing which shows the tip part of a catheter, (A) shows before cutting, (B) shows after cutting. It is sectional drawing which shows the state which inserted the catheter into a blood vessel, (A) shows the state which inserted the guide wire into a blood vessel, (B) the state which inserted the catheter into a blood vessel along the guide wire. It is a cross-sectional view showing a state in which a catheter is inserted into a blood vessel, (A) is a state in which a guide wire supported by the catheter is pushed into a stenosis, and (B) is a state in which a catheter with a cut middle portion is inserted into a blood vessel. Indicates the state. It is a cross-sectional view which shows the state which the catheter is inserted into the blood vessel, (A) is the state which inserted the balloon catheter into the blood vessel through the lumen of a catheter, (B) is the state which expanded the stenosis part by a balloon catheter. Shown. It is sectional drawing which shows the tip part of the catheter which is a modification, (A) is the first modification, (B) is the second modification, (C) is the third transformation, (D) is the third. A modified example of 4 is shown. It is sectional drawing which shows the tip part of the catheter which is a 5th modification, (A) is the state before cutting the intermediate part, (B) is a state after cutting an intermediate part, (C) is cut. Shows the state where the part is removed. It is sectional drawing which shows the tip part of the catheter which is a modification, (A) is a sixth modification, (B) is a seventh modification. It is sectional drawing which shows the tip part of the catheter which is 8th modification, (A) shows the state before cutting the intermediate part, (B) shows the state after cutting an intermediate part. It is sectional drawing which shows the tip part of the catheter which is the 9th modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dimensional ratios in the drawings may be exaggerated and differ from the actual ratios for convenience of explanation. In the following description, the hand side of the catheter is referred to as the "proximal side", and the side inserted into the living body is referred to as the "distal side".

The catheter 10 according to the present embodiment has a function as a support catheter for supporting the guide wire and a function as a guiding catheter for carrying the treatment device to the lesion portion. The support catheter is a catheter for supporting a guide wire penetrating a stenosis (including an occlusion) in a blood vessel (living 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-carrying catheter for transporting a contracted stent to a constricted portion to expand the diameter and expand and maintain the constricted portion.

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 grip 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 the external catheter 80, which is a general guiding catheter. The outer catheter 80 has a tubular outer catheter body 81, an outer catheter hub 82 located proximal to the outer catheter body 81, and a tip tip 83 located distal to the outer catheter body 81. The outer catheter body 81 has a lumen into which the catheter body 20 can be inserted.

The grip portion 40 is located outside the body during the procedure and is a portion that the technician grips and operates by hand. By gripping and operating the grip portion 40, the catheter 10 inserted into the blood vessel can be moved back and forth along the axial center and rotated about the axial center.

The shaft 30 is a portion that connects the grip portion 40 and the catheter body 20. The shaft 30 transmits the force acting on the grip portion 40 to the catheter body 20. The tip of the shaft 30 is fixed to the outer peripheral surface of the proximal end 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 flexible and long tube. The catheter body 20 is provided with a lumen 21 (lumen) at a substantially central portion thereof over the entire length of the catheter body 20. The catheter body 20 has a distal end 50 located distally, an intermediate 60, and a base 70.

The tip 50 is located on the most distal side of the catheter body 20. The tip 50 is a tubular portion that supports the guide wire inserted into the lumen 21. The tip portion 50 includes a tip opening 51 on the distal side through which the lumen 21 opens. The tip portion 50 has a tip taper portion 52 on the outer peripheral surface on the distal side. The outer diameter of the tip tapered portion 52 decreases in a tapered shape toward the distal side. The tip opening 51 is open at the most distal portion of the tip tapered 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 shape toward the distal side, and coincides with the inner diameter of the first inner peripheral surface 53 at a position connected to the first inner peripheral surface 53. The clearance between the first inner peripheral surface 53 and the guide wire to be inserted is small. Therefore, the first inner peripheral surface 53 can support the guide wire so as not to bend. Since the second inner peripheral surface 54 has a tapered shape, it is easy to insert the guide wire inside.

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

The inner diameter of the first inner peripheral surface 53 is appropriately set depending on the outer diameter of the guide wire to be used, and is, for example, 0.5 to 1.0 mm. The clearance between the first inner peripheral surface 53 and the guide wire to be inserted is appropriately set, and is, for example, 0.05 to 0.15 mm.

The constituent material of the tip portion 50 preferably has rigidity capable of supporting the guide wire, and for example, styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, transpolyisoprene-based, fluororubber-based, and chlorine. Examples thereof include various thermoplastic elastomers such as polyethylene chemicals, and one or a combination of two or more of them (polymer alloy, polymer blend, laminate, etc.) is preferable.

The intermediate portion 60 is a tubular portion provided on the proximal side of the tip portion 50. The intermediate portion 60 has a constant inner diameter and outer diameter. The inner diameter of the third inner peripheral surface 61 inside the intermediate portion 60 coincides with the inner diameter of 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 portion 60 is made of a material softer than the tip portion 50 and the base portion 70. The hardness of the material is, for example, the shore A hardness or the shore D hardness of the durometer test measured according to ISO 868. Therefore, the intermediate portion 60 can be cut more easily than the base portion 70 on a plane substantially orthogonal to the central axis (see FIG. 2B). Further, since the intermediate portion 60 is flexible, it does not damage the living tissue with which it comes into contact after being cut. On the outer peripheral surface of the intermediate portion 60, an identification portion 62 (see the shaded portion in FIG. 1) is provided to make the cuttable position visible. The identification unit 62 is displayed in a color different from that of the surroundings, for example. The identification portion 62 may be provided on the entire outer peripheral surface of the intermediate portion 60, or may be provided on a part of the outer peripheral surface. In addition, when the intermediate portion 60 is cut, it is necessary that a portion connected to the base portion 70 remains partially. The portion left connected to the base 70 of the intermediate portion 60 is a tip tip that flexibly contacts the living tissue. Therefore, the identification portion 62 does not have to be provided on the outer surface on the proximal side of the intermediate portion 60. This makes it possible to reliably leave a portion connected to the base 70 of the intermediate portion 60 after cutting. The identification unit does not have to have a different color from the surroundings as long as it is visible. For example, the identification portion may have a visible shape such as a groove or a recess. If the identification portion has a groove provided on the outer peripheral surface over 360 degrees, the blade can be easily guided and cutting can be easily performed.

The outer diameter of the intermediate portion 60 is appropriately set, and is, for example, 1.3 to 2.0 mm. The inner diameter of the intermediate portion 60 is appropriately set, and is, for example, 1.2 to 1.8 mm. 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 further preferably 4 to 6 mm. If the intermediate portion 60 is too long, the catheter body 20 tends to bend at the intermediate portion 60, and the function as a support catheter deteriorates. If the intermediate portion 60 is too short, cutting becomes difficult. Further, if the intermediate portion 60 is too short, the tip tip after cutting becomes short, and the living tissue in contact with the tip is easily damaged.

The constituent material of the intermediate portion 60 is preferably a material that is easy to cut and has high flexibility so as not to damage the living tissue in contact with the intermediate portion 60. The constituent materials of the intermediate portion 60 include various rubber materials such as natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, silicone rubber, fluororubber, and styrene-butadiene rubber, and styrene-based, polyolefin-based, polyurethane-based, and polyester-based materials. , Polyethylene-based, polybutadiene-based, transpolyisoprene-based, fluororubber-based, chlorinated polyethylene-based, and various other thermoplastic elastomers are suitable.

The intermediate portion 60 may include an X-ray opaque material (X-ray contrast agent) in the constituent material. By including an X-ray opaque material, the position can be confirmed under fluoroscopy. The X-ray opaque material is, for example, barium sulfate, bismuth oxide, tungsten or the like. The ratio of the X-ray opaque material to be blended in the constituent material is, for example, 30 to 80 wt%.

The base 70 is a tubular portion provided on the proximal side of the intermediate 60. The base 70 includes a base opening 71 on the proximal end surface where the lumen 21 opens. The base 70 has a constant inner and outer diameter. The inner and outer diameters of the base 70 coincide with the inner and outer diameters of the intermediate 60. The inner diameter of the fourth inner peripheral surface 72 inside the base 70 is larger than the inner diameter of the first inner peripheral surface 53. The inner diameter of the base 70 does not have to match the inner diameter of the intermediate portion 60. Further, the outer diameter of the base portion 70 does not have to match the outer diameter of the intermediate portion 60. For example, the inner and outer diameters of the base 70 may decrease towards the distal side. The base 70 has 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 on the outside of the inner layer 73 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 material having low friction so that a medical device such as a treatment device or a guide wire can be easily moved in the lumen 21. Therefore, the passability of the medical device is improved, and the operability is improved. Examples of the low friction material constituting the inner layer 73 include fluororesin 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-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, transpolyisoprene-based, fluororubber-based, chlorinated polyethylene-based, and the like. Various thermoplastic elastomers and the like can be mentioned, and one or a combination of two or more of them (polymer alloy, polymer blend, laminate, etc.) can be used.

The reinforcing portion 75 is a portion for reinforcing the base portion 70. The reinforcing portion 75 has a plurality of reinforcing lines. The material of the outer layer 74 or the inner layer 73 has entered the gaps between the plurality of reinforcing lines in the reinforcing portion 75. The reinforcing portion 75 is, for example, a reinforcing wire formed into 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 wall thickness of the base 70 in the radial direction can be reduced. The reinforcing wire is not limited to the flat wire, and may be, for example, a round wire or an elliptical wire. Further, each reinforcing wire may be a bundle of two or more reinforcing wires.

The number of layers constituting the base 70, the constituent materials of each layer, the presence or absence of reinforcing wires, and the like may differ along the axial direction of the base 70. Further, the base portion 70 does not have to have the reinforcing portion 75. Further, the tip portion 50 and the intermediate portion 60 may also be composed of a plurality of layers.

The catheter body 20 may be at least partially curved. When the catheter body 20 is curved, the pushing direction can be selected by rotating it. This improves passage through curved blood vessels. Further, when the catheter body 20 is curved, it becomes 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 narrowed portion N in the blood vessel is expanded by the balloon catheter 100 (treatment device). The catheter 10 is used together with an external catheter 80 into which the catheter 10 can be inserted. The catheter 10 may not be used together with the outer catheter 80.

First, an introducer sheath (not shown) is percutaneously inserted into the blood vessel, and the guide wire 90 is inserted into the blood vessel through the introducer sheath as shown in FIG. 3 (A). Next, the guide wire 90 is pushed forward to reach the narrowed portion N.

Next, the catheter 10 is inserted into the outer catheter 80 and penetrated. Next, the proximal end of the guide wire 90 located outside the body is inserted into the lumen 21 through the distal opening 51 of the catheter 10. Subsequently, the catheter 10 is moved distally together with the outer catheter 80 along the guide wire 90 and inserted into the blood vessel via the introducer sheath. After that, the catheter 10 is pushed distally together with the outer catheter 80 to reach the vicinity of the stenosis N as shown in FIG. 3 (B). If the intermediate portion 60 contains an X-ray opaque material, the position of the intermediate portion 60 can be easily confirmed under fluoroscopy.

Next, the grip portion 40 is operated to move the catheter 10 in the distal direction. As a result, the tip tapered portion 52 is pushed into the narrowed portion N. As a result, the tip opening 51 that opens on the most distal side of the tapered tip taper 52 is positioned at the center of the blood vessel lumen (the center of the stenosis N). Next, while maintaining the catheter 10 in this state, the guide wire 90 is pushed in the distal direction. As a result, as shown in FIG. 4A, the guide wire 90 protrudes from the tip opening 51 positioned at the center of the narrowed portion N and can be pressed against the center of the narrowed portion N. After this, the guide wire 90 is further pushed in the distal direction. At this time, since the tip portion 50 is harder than the intermediate portion 60 and the clearance between the first inner peripheral surface 53 of the tip portion 50 and the guide wire 90 is small, the guide wire 90 is hard to bend and the pushing force is hard 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 more difficult to bend and the pushing force is hard to escape. Therefore, a sufficient pushing force for passing through the narrowed portion N can be satisfactorily transmitted from the hand to the tip portion 50 of the guide wire 90. Therefore, the guide wire 90 can easily penetrate the narrowed portion N. In this way, the catheter 10 functions as a support catheter that supports the guide wire 90.

After the guide wire 90 has penetrated the constriction N, the catheter 10 is withdrawn from the outer catheter 80, leaving the guide wire 90. As a result, the catheter 10 is located outside the body. Next, as shown in FIG. 2B, the intermediate portion 60 is cut at a cross section intersecting the central axis thereof by a cutting means such as scissors, a scalpel, a knife, or a heating wire. At this time, since the identification portion 62 is provided on the outer surface of the intermediate portion 60, an appropriate position of the intermediate portion 60 can be easily cut. 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 part of the tip 50 and the middle 60 distal to the cut surface is discarded. As a result, the tip portion 50 having a small inner diameter is removed from the catheter body 20.

Next, the proximal end 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 distally to reach near the stenosis N, as shown in FIG. 4 (B). 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 tip portion 50 and the base portion 70. Therefore, even if the catheter 10 is pushed forward in the curved, bent, or branched blood vessel, the flexible intermediate portion 60 comes into contact with the blood vessel. Therefore, the catheter 10 can be smoothly and safely moved in the blood vessel. Further, if the intermediate portion 60 contains an X-ray opaque material, the position of the intermediate portion 60 can be easily confirmed under fluoroscopy.

Next, the balloon catheter 100 is inserted through the proximal 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 through the lumen 21 to the vicinity of the stenosis N. Since the tip portion 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. After that, as shown in FIG. 5 (A), the balloon catheter 100 is inserted into the stenosis portion N. After that, as shown in FIG. 5B, the balloon 101 can be expanded to expand the narrowed portion N.

Next, the balloon 101 is contracted. Subsequently, the balloon 101 is pulled into the lumen 21 of the catheter 10, moved to the proximal side, and removed from the blood vessel. After this, the catheter 10 is pulled out of the blood vessel to complete the procedure.

As described above, the catheter 10 according to the present embodiment is a catheter 10 having a lumen, which is a tubular tip portion 50 having a tip opening 51 having a lumen opening on the distal side, and a tip portion 50. It has a tubular intermediate portion 60 provided on the proximal side and a tubular base 70 provided on the proximal side of the intermediate portion 60, and the inner diameter of at least a part of the tip portion 50 is the intermediate portion 60 and the base 70. Smaller than the minimum inner diameter of, the middle portion 60 is more flexible than the tip portion 50 and the base portion 70. The catheter 10 configured as described above is used as a support catheter by utilizing the tip portion 50 having a small inner diameter, and then cuts the intermediate portion 60 which is located on the proximal side of the tip portion 50 and is more flexible than the base portion 70. Therefore, the tip portion 50 having a small inner diameter can be separated. As a result, the catheter 10 can also be used as a guiding catheter for transporting the treatment device. Therefore, the present catheter 10 can exert the functions of the support catheter and the guiding catheter by itself. By the way, the catheter 10 is a rapid exchange type and is less likely to exert a pushing force than the over-the-wire type. However, by adopting the rapid exchange type, it is easy to insert and remove the blood vessel, and it is easy to cut at the intermediate portion 60.

Further, the tip portion 50 has a tip tapered portion 52 whose outer diameter decreases in a tapered shape toward the tip opening 51. As a result, when the catheter 10 is pushed into the stenosis portion N in the living lumen, the tip opening 51 located on the distal side of the tip taper portion 52 is guided to the center of the stenosis portion N. Therefore, the guide wire 90 can be pressed against the center of the narrowed portion N by projecting the guide wire 90 from the tip opening 51 to the distal side through the lumen of the catheter 10.

Further, the catheter 10 further has a reinforcing portion 75 which is a wire rod, 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 the range. As a result, the reinforcing portion 75 can increase the rigidity of the base portion 70 to improve the pushability, kink resistance, and torque transmission in the blood vessel, and make it possible to cut the intermediate portion 60. Further, since the reinforcing portion 75 is not located in the intermediate portion 60, the reinforcing portion 75 is not exposed from the cut surface after cutting the intermediate portion 60. Therefore, damage to the living tissue that comes into contact with the intermediate portion 60 after cutting can be suppressed, and safety can be enhanced.

Further, the intermediate portion 60 has an identification portion 62 that can be visually identified. As a result, the cutting position can be easily identified, and an appropriate position can be reliably cut.

Further, the method of using the catheter 10 described above includes a step of inserting the guide wire 90 into the lumen of the catheter 10 and supporting the guide wire 90 with the tip portion 50, a step of pulling out the guide wire 90 from the catheter 10, and the catheter 10. It has a step of cutting the catheter 10 at an intermediate portion 60 and a step of 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 support the guide wire 90 with the tip portion 50, operate the guide wire 90, cut the intermediate portion 60, and use the catheter 10 to convey the treatment device. Can be done. Therefore, the 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 tip portion 50 while supporting the catheter 10 by the outer catheter 80. As a result, 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. Therefore, a high pushing force for the narrowed portion N of the guide wire 90 can be obtained.

The present invention also includes a treatment method (treatment method) using the catheter 10 described above. The treatment method consists of a step of inserting the guide wire 90 into the lumen of the catheter 10 in the living lumen, and pressing the tip 50 against the narrowed portion N in the living lumen while pressing the guide wire 90 into the narrowed portion. A step of pushing into N, a step of pulling out the catheter 10 from the lumen of the living body, a step of cutting the catheter 10 at the intermediate portion 60, a step of inserting the catheter 10 into the lumen of the living body, and a step close to the lumen of the catheter 10. It has a step of inserting a treatment device from the lumen 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 constriction N and use the catheter 10 to transport the treatment device. Therefore, in this treatment method, the guide wire 90 can be supported and the treatment device can be conveyed by one catheter 10.

The present invention is not limited to the above-described embodiment, 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. The parts having the same functions as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted. As a result, the range for supporting the guide wire 90 of the tip portion 110 is expanded, and the function as a support catheter is improved. The second inner peripheral surface 121 whose inner diameter decreases in a tapered shape toward the distal side is located at the intermediate portion 120. As described above, the inner diameter on the distal side of the intermediate portion 120 may be smaller than the inner diameter on the proximal side of the intermediate portion 120.

Further, as in the second modification shown in FIG. 6B, the outer peripheral surface 131 and the inner peripheral surface 132 of the tip portion 130 may be curved surfaces that are convex outward in the radial direction of the catheter. As a result, the position where the first inner peripheral surface 53 of the tip portion 130 is provided becomes thick, and the guide wire 90 can be firmly supported. Therefore, the function of supporting the guide wire 90 as a support catheter is improved. Therefore, a high pushing force for the narrowed portion N of the guide wire 90 can be obtained. Further, since the outer peripheral surface 131 of the tip portion 130 becomes smooth, damage to living tissue can be suppressed and safety is improved.

Further, as in the third modification shown in FIG. 6C, the most distal portion of the tip portion 140 may have a tubular shape having a constant inner and outer diameters. As a result, a range having a constant outer diameter is provided at the position where the tip opening 51 is provided. Therefore, the length that can support the guide wire 90 (the length of the first inner peripheral surface 141 in the axial direction) can be arbitrarily set, and the degree of freedom in design is improved.

Further, as in the fourth modification shown in FIG. 6D, the tip portion 150 has a first inner peripheral surface 151, which 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 modification shown in FIG. 7A, an auxiliary portion 160 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 the distal end portion is fixed to the tip portion 170 by fusion or adhesion. A groove portion 161 is provided on the outer peripheral surface of the auxiliary portion 160 over 360 degrees in the circumferential direction. It is preferable that an identification portion 62 is provided at a position corresponding to the groove portion 161 on the outer peripheral surface of the intermediate portion 60 so that the position of the groove portion 161 can be visually identified. Since the auxiliary portion 160 supports the flexible intermediate portion 60, the intermediate portion 60 is less likely to bend. Therefore, the function as a support catheter for supporting the guide wire 90 is improved. When cutting the intermediate portion 60, as shown in FIG. 7B, the intermediate portion 60 can be cut while supporting the intermediate portion 60 by the auxiliary portion 160, so that the intermediate portion 60 is difficult to escape due to the pressing force of the blade. Therefore, cutting becomes easy. Further, since the intermediate portion 60 can be cut along the groove portion 161, it is possible to reliably cut at an appropriate 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. Therefore, damage to the living tissue in contact with the intermediate portion 60 can be further suppressed, and safety can be enhanced. The auxiliary portion 160 is not connected to the intermediate portion 60 and can be separated from the intermediate portion 60. Therefore, after cutting the intermediate portion 60, the tip portion 170 can be removed as shown in FIG. 7 (C). 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 with the inner peripheral surface. When the auxiliary portion 160 comes into contact with the intermediate portion 60, the flexible intermediate portion 60 can be supported more strongly, and the function as a support catheter for supporting the guide wire 90 is improved. In FIG. 6, the shape of the groove portion 161 is an acute angle in the depth direction in the cross section passing through the central axis of the catheter 10 so that the cutting blade can easily follow. However, the shape of the groove is not limited to this. Therefore, the edge portion 162 of the groove portion 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 thinner than the base portion 70 and therefore more flexible 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 rather than being flexible depending on the constituent materials.

Further, as in the seventh modification 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 by not providing the reinforcing portion 75.

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 within the range where the tip portion 50 is provided in the axial direction of the catheter 10. Each wire rod of the reinforcing portion 200 has a partial cross section D located in a range where the base portion 70 is provided, and is divided (cut) in the axial direction of the catheter 10. As a result, after cutting the intermediate portion 60, when the intermediate portion 60 on the tip portion 50 side is separated from the base portion 70, as shown in FIG. 9B, the intermediate portion 60 is separated together with the cut intermediate portion 60 on the distal side. The reinforcing portion 200A located at is removed. As a result, even if the reinforcing portion 200 is provided in the intermediate portion 60, the wire rod is not exposed from the cut surface of the intermediate portion 60 connected to the base portion 70. Therefore, damage to the living tissue in contact with the intermediate portion 60 can be suppressed, and safety can be enhanced. Further, since the intermediate portion 60 before cutting is reinforced by the reinforcing portion 200, the intermediate portion 60 is less likely to bend. As a result, the function as a support catheter for supporting the guide wire 90 is improved. When cutting the intermediate portion 60, it is difficult to cut the portion of the intermediate portion 60 on the inner peripheral surface side of the reinforcing portion 200 because the blade does not pass through the portion. However, since the intermediate portion 60 is flexible, the cut surface extends from the cut portion, and the entire intermediate portion 60 can be cut. Alternatively, a notch for promoting cutting may be provided inside (inner peripheral surface side) of the reinforcing portion 200 of the intermediate portion 60 over 360 degrees or partially. The reinforcing portion located in the intermediate portion 60 may be, for example, a wire rod extending linearly in the axial direction so as to be easily pulled out. Therefore, the reinforcing portion located in the intermediate portion 60 may have a structure different from that of the reinforcing portion located in the base portion 70.

Further, as in the ninth modification shown in FIG. 10, a convex portion 211 projecting outward in the radial direction may be provided on the outer peripheral surface of the tip portion 210. The convex portion 211 is provided over 360 degrees in the circumferential direction of the outer peripheral surface, but may be partially provided. As a result, 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. Therefore, when pushing the guide wire 90 inserted into the lumen 21, the catheter 10 is inserted into the lumen of another outer catheter 80, and the guide wire 90 is inserted into the narrowed portion N while supporting the catheter 10 by the outer catheter 80. Can be pushed in. As a result, 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. The convex portion 211 on the outer peripheral surface of the catheter 10 may be located at an intermediate portion instead of the distal end portion.

The use of the catheter 10 is not particularly limited as long as it is used by being inserted into the lumen of a living body. The biological lumen is not limited to blood vessels, and may be, for example, a vascular duct, a ureter, a bile duct, an oviduct, a hepatic duct, or the like.

In addition, the catheter may be an over-the-wire type catheter.

Further, the distal end surface on which the tip opening of the catheter body is provided may be a flat flat surface without protruding in a tapered shape.

10 catheter,
20 Catheter body,
21 lumens,
50, 110, 130, 140, 150, 170, 210 tip,
51 Tip opening,
52 Tip taper,
60, 120, 180, 190 middle part,
62 Identification unit,
70 base,
71 Base end opening,
75, 200 reinforcements,
80 outer catheter,
90 guide wire,
100 balloon catheter (treatment device),
160 Auxiliary part,
161 groove,
211 convex part,
N stenosis.

Claims (8)

A catheter that has a lumen and supports a guide wire that is inserted into the lumen.
A tubular tip with a tip opening that opens the lumen on the distal side,
A tubular intermediate portion provided on the proximal side of the tip portion and
It has a tubular base provided on the proximal side of the intermediate portion and
At least a portion of the inner diameter of the tip, the smaller than minimum inside diameter of the intermediate portion and the base portion, the intermediate portion is Ri flexible der than the tip portion and the base portion,
Said intermediate portion, that have a discrimination unit that can be identified by visual catheter. The catheter according to claim 1, wherein the proximal end of the identification portion is provided on the distal side of the connecting portion between the intermediate portion and the base portion. The catheter according to claim 1 or 2 , wherein the tip portion has a tip tapered portion whose outer diameter decreases in a tapered shape toward the tip opening. It also has a reinforcing part that is a wire rod,
The catheter according to any one of claims 1 to 3, wherein the reinforcing portion is located in a range different from the range in which the intermediate portion is provided and is located in a range in which the base portion is provided in the axial direction of the catheter. .. It also has a reinforcing part that is a wire rod,
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 any one of claims 1 to 3, wherein the reinforcing portion is divided in the 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 5, which is located in the lumen of the intermediate portion and has an auxiliary portion which is capable of being separated from the intermediate portion and is connected to the tip portion. The catheter according to claim 6, wherein the auxiliary portion has a groove portion extending in the circumferential direction on the outer peripheral surface. The catheter according to any one of claims 1 to 7, wherein a convex portion is provided on the outer peripheral surface of the tip portion or the intermediate portion.

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