JP2011010787A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter easily delivered or passing through a lesion even in the lesion with a severe constriction such as a CTO lesion on the distal end side within a bending blood vessel, reducing the risk of a radio-opaque marker disposed at the distal end of the catheter being caught, and reducing the risk of dropping of a distal end chip including a ring marker even if the radio-opaque marker is caught by any possibility.SOLUTION: The catheter is composed of an inner layer, an outer layer, a reinforcing layer disposed between the layers, the radio-opaque marker disposed at the distal end of the catheter, and a hub disposed in the proximal end side of the catheter. At least part of the radio-opaque marker is closely attached to the inner layer and/or reinforcing layer by fusing.

Description

  The present invention relates to a catheter used for medical applications, and more particularly, percutaneous angioplasty (PTA: Percutaneous Transgenic Angioplasty, PTCA: Percutaneous Transluminal Coronary Angioplasty). ), A penetration catheter for penetrating a stenosis, an infusion catheter capable of administering a therapeutic substance to a local site, a guiding catheter, and the like.

  Conventionally, percutaneous angioplasty has been widely used for the purpose of expanding or treating stenosis or occlusion in a blood vessel lumen and restoring or improving blood flow in a coronary artery or a peripheral blood vessel. A typical surgical procedure for PTCA using a balloon catheter is as follows. First, a guiding catheter is inserted from a puncture site such as the femoral artery, brachial artery, and radial artery, and the distal end thereof is placed at the entrance of the coronary artery via the aorta. Next, the guide wire inserted through the guide wire lumen is advanced beyond the stenotic site of the coronary artery, and a balloon catheter is inserted along the guide wire so that the balloon matches the stenosis. Next, using a device such as an inflator, a pressure fluid is supplied to the balloon via the inflation lumen, and the balloon is inflated to expand the stenosis. After dilatation treatment of the stenosis, PTCA is terminated by retracting the balloon under reduced pressure and removing it from the body.

  For a lesion with a very high degree of stenosis or a chronic total occlusion, a guide wire may not be advanced beyond the stenosis site and treatment may not be possible. In such a case, a microcatheter or a penetration catheter is used, and the advancement of the guide wire beyond the stenosis site is realized.

  In addition, during PTCA, local administration of a therapeutic substance to a stenotic site may be required. An example of such treatment is local administration of a thrombolytic agent to dissolve the thrombus. In such a case, an infusion catheter for locally administering the therapeutic substance is used.

  Among treatment subjects using medical dilatation catheters, dilation treatment is especially special for chronic total occlusion (CTO) lesions in coronary arterial blood vessels. I will master it.

  For special lesions as described above, the guide wire is passed through the lesion while the guide wire is backed up by a microcatheter, a penetrating catheter or the like. Furthermore, there are cases where a microcatheter or a penetration catheter is passed through the stenosis part in advance in order to facilitate the passage of the stenosis part of an expansion therapy device such as a balloon catheter or a stent delivery catheter. In some cases, the guide wire is exchanged after a microcatheter, a penetrating catheter, or the like is passed through the stenosis. When a flexible catheter is passed through a lesion having severe stenosis as described above, an X-ray impermeable marker arranged at the distal end of the catheter may be caught on the stenosis. At this time, if the catheter is forcibly pulled out, the radiopaque marker falls off and the risk of remaining in the body becomes very high. As measures against this, generally, the tip break strength is improved by increasing the cross-sectional area of the catheter by increasing the outer diameter, and the tip break strength is improved by making the outer layer resin of the tip rigid. When it is applied to a catheter for passing through severely bent blood vessels or severe stenotic lesions, the intended performance cannot be realized.

  In view of the above, the problem to be solved by the present invention is that delivery and lesion passage can be easily performed even in a severely stenotic lesion such as a CTO lesion on the distal side in a bent blood vessel, and a catheter It is an object of the present invention to provide a catheter that reduces the trapping of the radiopaque marker arranged at the tip and reduces the risk of dropping the tip including the ring marker even if the marker is trapped.

(1) The catheter of the present invention is
An inner layer, an outer layer, a reinforcing layer disposed between them, a radiopaque marker disposed at a distal end portion of the catheter, and a hub disposed on the proximal side of the catheter,
The catheter is characterized in that at least a part of the radiopaque marker is in close contact with the inner layer and / or the reinforcing layer by melting.

  According to the present invention, since the radiopaque marker is in close contact with the inner layer and / or the reinforcing layer, it is possible to improve the dropping strength of the tip including the radiopaque marker.

(2) The catheter of the present invention further includes
The catheter according to (1), wherein at least a part of the radiopaque marker has a notch, and the notch is in contact with an inner layer and an outer layer.

  According to the present invention, since the radiopaque marker is in close contact with the inner layer and / or the outer layer, it is possible to improve the dropping strength of the tip including the radiopaque marker. Furthermore, since the inner layer and the outer layer are bonded to at least a part of the radiopaque member, the radiopaque member is restrained, and the dropout strength of the tip including the radiopaque marker is reduced. Further improvements are possible.

(3) The catheter of the present invention further includes
The catheter according to (1), wherein the radiopaque marker has a cutout portion at least in part, and the cutout portion has an inner layer and an outer layer in contact with each other through an adhesive member.

  According to the present invention, since the radiopaque marker is in close contact with the inner layer and / or the outer layer, it is possible to improve the dropping strength of the tip including the radiopaque marker. Furthermore, since the inner layer and the outer layer are bonded to at least a part of the radiopaque member, the radiopaque member is restrained, and the dropout strength of the tip including the radiopaque marker is reduced. Further improvements are possible.

(4) The catheter of the present invention further includes
A catheter composed of an inner layer, an outer layer, a reinforcing layer disposed between them, a radiopaque marker disposed at a distal end portion of the catheter, and a hub disposed on the proximal side of the catheter. ,
The catheter is characterized in that it has a cutout portion in at least a part of the radiopaque marker, and the cutout portion is in contact with an inner layer and an outer layer.

  By fixing the radiopaque marker in the inner layer and the outer layer according to the present invention, it is possible to improve the dropout strength of the tip including the radiopaque marker.

  The above-described features of the present invention and other features and their advantages will be made clear by the following embodiments and drawings.

  The catheter of the present invention can reduce the catch of the radiopaque marker while improving the diameter and flexibility of the catheter, and can improve the dropout strength of the catheter tip including the radiopaque marker. To provide a catheter.

FIG. 1 is an overall view of an over-the-wire type (OTW type) of catheters according to an embodiment of the present invention. FIG. 2 is an overall view of a high-speed exchange type (RX type) among the catheters according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view in the catheter major axis direction of the drive unit of the catheter in one embodiment of the present invention, and a schematic sectional view in the catheter minor axis direction on the A-A ′ plane. FIG. 4 is a schematic sectional view in the catheter major axis direction of the distal end portion of the catheter according to another embodiment of the present invention. FIG. 5 is a schematic cross-sectional view in the catheter major axis direction of the distal end portion of the catheter according to another embodiment of the present invention.

  Next, embodiments of the present invention will be described with reference to the drawings. Hereinafter, although a penetration catheter is illustrated, this invention is not limited to this. The catheter of the present invention is well known to those skilled in the art, such as a vascular treatment catheter having a balloon or a stent, a guide wire introduction catheter (including a microcatheter) for inserting a medical device, a guiding catheter, and the like. Any catheter is included.

1. Catheter Structure FIG. 1 is an overall view of an over-the-wire type (OTW type) of catheters according to an embodiment of the present invention. FIG. 2 is an overall view of a high-speed exchange type (RX type) among the catheters according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view in the catheter major axis direction of the distal end portion of the catheter in one embodiment of the present invention, and a schematic cross-sectional view in the catheter minor axis direction in the AA ′ plane.

  The catheter 21 includes the lumen 11. The lumen 11 extends from the distal opening 12 to the proximal opening 13 of the catheter 21. An inner layer 1 that forms a lumen is provided outside the lumen 11. A reinforcing layer 3 is provided outside the inner layer 1, and an outer layer 2 is further provided outside the reinforcing layer 3.

An X-ray opaque marker 4 is provided near the distal opening 12 of the catheter 21. The proximal end side opening 13 of the catheter 21 includes a hub 5.
At least a part of the radiopaque marker may be in close contact with the inner layer 1 and / or the reinforcing layer 3 by melting. Since the radiopaque marker is in close contact with the inner layer 1 and / or the reinforcing layer 3, it is possible to improve the drop-off strength of the tip including the radiopaque marker 4. The term “adhesion” as used herein means all states in which contact is possible, such as pressure bonding, alloying, integration by melting, and sticking. Considering the simplicity of the process, it is preferable to melt the X-ray opaque marker 4 by irradiating a laser from the outside of the X-ray opaque marker 4 and to adhere to the inner layer 1 and / or the reinforcing layer 3. At this time, when the metal melted by laser irradiation rises on the radiopaque marker and increases the outer diameter, the outer diameter can be suppressed by flattening the radiopaque marker thereafter, which is preferable. . Further, when the notch is opened in the radiopaque marker 4, the outer layer flows at the stage where the outer layer 2 to be coated later is melted and comes into contact with the inner layer by the outer layer 2 to contact the inner layer. It is more preferable because it is possible to improve the tensile rupture strength of the tip portion including the radiopaque marker while suppressing the increase in the thickness. The notch referred to here includes all structures that allow the inner layer 1 and the outer layer 2 to contact each other, such as a hole, a crack, and a pitch when a radiopaque marker is made into a coil structure. The term “contact” as used herein includes all contacts including chemical bonding such as welding, physical bonding such as pressure bonding, adhesion, and adhesion.

2. Inner layer The inner layer 1 may be disposed over the entire length of the catheter 21, but the distal end of the inner layer 1 may be provided midway closer to the proximal end than the distal end of the outer layer 2. The inner layer 1 is preferably a single member from the viewpoint of ease of manufacture. For example, when the inner layer 1 needs to be changed in rigidity, a plurality of members may be joined in the middle of the catheter 21. .

  A guide wire, a chemical solution, or the like can pass through the inside of the inner layer 1. The inner layer 1 preferably has a single inner diameter from the viewpoint of ease of manufacture. For example, in order to further improve the passage to the CTO lesion, the outer diameter is reduced toward the distal end side of the catheter 21 at the same time. The inner diameter may be reduced.

The inner layer 1 is preferably made of a material that has good chemical resistance, antithrombogenicity, and slidability of the guide wire, such as a fluorine-based resin and high-density polyethylene. Moreover, when using the material which is not provided with the characteristic requested | required of an inner layer, such as antithrombogenicity, you may provide the characteristic requested | required of an inner layer by coating.
The thickness of the inner layer 1 is not particularly limited, but in order to suppress the outer diameter of the catheter 21, it is preferable that the inner layer 1 be thinned so that the breaking strength of the inner layer 1 can withstand actual use.

3. Reinforcing layer The inner layer 1 can also include a reinforcing layer 3. Including the reinforcing layer 3 is preferable because kink resistance can be improved.

  The reinforcing layer 3 is not particularly limited as long as it exhibits the above characteristics. Preferable examples include a metal coil, a metal braid, a metal core wire, a resin coil, a resin braid, a resin wire, or the like.

4). Outer layer The outer layer 2 is not particularly limited as long as it is a resin tube. Suitable examples include polyolefins, polyolefin elastomers, polyesters, polyester elastomers, polyamides, polyamide elastomers, polyurethanes and polyurethane elastomers. The outer layer 3 is preferably connected with resins of various hardnesses so that the change in rigidity is gradual. Furthermore, the outer diameter of the outer layer 2 may be reduced toward the distal end of the catheter 21 in order to further improve the permeability to the CTO lesion.

5. Hydrophilic coating The outer surface of the catheter 21 can be provided with a hydrophilic coating in order to facilitate insertion into a blood vessel or a guide catheter. That is, it is possible to apply a hydrophilic coating that exhibits lubricity when it comes into contact with blood on at least a portion of the outer layer 2 that comes into contact with blood. However, the site where the hydrophilic coating is applied and the length of the coating can be determined according to the purpose of use of the catheter. The type of the hydrophilic coating does not limit the effect of the present invention, and poly (2-hydroxyethyl methacrylate), polyacrylamide, polyvinyl pyrrolidone, maleic anhydride polymer (for example, methyl vinyl ether maleic anhydride copolymer). A hydrophilic polymer such as a maleic anhydride copolymer such as a polymer can be suitably used, and the coating method is not limited.

  When the catheter is a balloon catheter, depending on the intended use, a hydrophobic coating can be applied to the outer surface of the balloon to prevent the balloon from slipping when the balloon is expanded. The kind of the hydrophobic coating is not particularly limited, and a hydrophobic polymer such as silicone can be preferably used.

6). Radiopaque marker The radiopaque marker 4 can be provided in the vicinity of the opening on the distal end side of the catheter 21. The material of the radiopaque marker 4 is not particularly limited as long as it is substantially radiopaque, and the type of metal or resin material is not limited. The radiopaque marker 4 may include only one marker, or may include two or more markers. Each marker is on the inner layer 1 and may be covered and fixed by the outer layer 2. Thereby, it can manufacture easily. Moreover, the shape of the marker 33 is not ask | required, However, It is preferable that it is a hollow ring shape. Since the hollow ring-shaped shape looks the same when viewed from any radial direction of the catheter 1 under X-ray contrast, visualization is easy. Moreover, it can be manufactured easily.

7). The hub 5 can be provided near the proximal opening 13 of the hub catheter 21. As a material constituting the hub 5, resins such as polycarbonate, polyamide, polyurethane, polysulfone, polyarylate, styrene-butadiene copolymer, and polyolefin can be suitably used.

  The method for joining the hub 5 and the catheter 21 is not particularly limited, and a known technique can be applied. For example, when it is made of a material that can be bonded and fused with an adhesive, a method such as fusion can be used. Moreover, when using an adhesive agent, the composition and chemical structure of the adhesive agent and the curing type are not limited. In other words, urethane type, silicone type, epoxy type, and cyanoacrylate type adhesives are preferably used in terms of composition and chemical structure, and in terms of curing type, two-component mixed type, UV curable type, water absorption An adhesive such as a curable type or a heat curable type is preferably used. When using an adhesive, it is preferable to use an adhesive having a hardness after curing such that the rigidity of the joining part does not change discontinuously before and after the joining part, such as the material, dimensions, rigidity, etc. of the joining part It is possible to select an adhesive in consideration of the above. In order to reduce the diameter of the joint part, the joint part may be heat-treated. In the case of a difficult-to-adhere material such as polyolefin, the joint part is plasma treated with oxygen gas to improve the adhesion. It is also possible to bond them after making them.

8). Balloon When the catheter 21 is a balloon catheter, a balloon may be provided near the distal end side opening 12 of the catheter 21. Examples of a method for producing a balloon that can be inflated and deflated by adjusting the internal pressure include dipping molding and blow molding, and an appropriate method can be selected according to the intended use. In the case of a PTCA balloon catheter, blow molding is preferred in order to obtain sufficient pressure strength. An example of a method for producing a balloon by blow molding is shown below. First, a tubular parison having an arbitrary size is formed by extrusion molding or the like. The tubular parison is placed in a mold having a mold that matches the balloon shape, and stretched in the axial direction and the radial direction by a biaxial stretching process, thereby forming a balloon having the same shape as the mold. In addition, a biaxial stretching process may be performed on a heating condition and may be performed in multiple times. Further, the axial stretching may be performed simultaneously with or before or after the radial stretching. Furthermore, an annealing process may be performed to stabilize the shape and dimensions of the balloon.

  The balloon has joints on the straight pipe part and the front end side and the rear end side thereof, and has a tapered part between the straight pipe part and the joint part. The size of the balloon is determined by the intended use of the balloon catheter. The outer diameter of the straight tube part when expanded by adjusting the internal pressure is 1.50 mm to 35.00 mm, preferably 1.50 mm to 30.00 mm. The length of the straight pipe portion is 5.00 mm to 80.00 mm, preferably 7.00 mm to 60.00 mm.

  The resin type of the tubular parison is not particularly limited, and for example, polyolefin, polyolefin elastomer, polyester, polyester elastomer, polyamide, polyamide elastomer, polyurethane and polyurethane elastomer can be used, and two types of these resins can be used. A blend material obtained by mixing the above or a material having a multilayer structure in which two or more kinds are laminated may be used.

9. Side hole When the catheter 21 is an injection catheter, a side hole may be provided in the vicinity of the distal end side opening of the catheter 21. The size, position, number, and the like of the side holes do not limit the effects of the present invention, and can be arbitrarily set according to the characteristics of the therapeutic substance to be used. Moreover, the production method of a side hole is not specifically limited, either cutting, laser processing, etc. can be used.

10. Functional Examples of Catheter Each of the catheters described above is roughly classified into two according to the length of the lumen 11. Hereinafter, a general balloon catheter in which a balloon is connected to the vicinity 12 of the distal end side opening of the catheter 21 and a port for supplying pressure fluid for adjusting the internal pressure of the balloon 6 to the hub 5 will be described.

  As shown in FIG. 1, the lumen 11 is provided over the entire length of the catheter 21, and the lumen 5 is provided with a rear-end opening 13 on the rear end side of the lumen. It is an over-the-wire type (OTW type) in which a distal end side opening 12 of the lumen 11 is provided on the side. The other is a high-speed exchange type (RX) in which the lumen 11 exists only at the distal end side of the catheter 21 and the rear end side opening 13 of the guide wire lumen is provided in the middle of the shaft of the catheter 21 as shown in FIG. Type). Since the lumen 11 exists over the entire length of the balloon catheter 21, the OTW type is often used for passing a guide wire as a backup for a lesion that is difficult to pass. On the other hand, in the RX type, since it is easy to remove the balloon catheter while the guide wire is left in the affected area, it may be used.

  Specific examples according to the present invention are described in detail below, but the present invention is not limited to the following examples. Hereinafter, in order to clarify the structure of the tube as an example, for the sake of convenience, the name of each element and the reference numerals (for example, tubes 1, 2, etc.) attached to each element have been described in the above embodiments. In the drawings, description will be made assuming that the names of the elements and the elements indicated by the same reference numerals correspond to the elements.

  In Example 1, the X-ray opaque marker 4 caulked on the outer side of the inner layer 1 coated with the reinforcing layer 3 was irradiated with a laser and melted to adhere to the inner layer 1 and the reinforcing layer 3. Thereafter, the outer layer was coated to obtain Sample 1.

  In Example 2, the X-ray opaque marker 4 was irradiated with a laser, melted, and adhered to the inner layer 1 and the reinforcing layer 3. At this time, a hole was opened in the radiopaque marker 4 and the radiopaque marker 4 was raised, so that the radiopaque marker 4 was flattened. Thereafter, the outer layer 1 was coated. At this time, the outer layer 1 was in close contact with the inner layer 1 through the hole of the radiopaque marker 4. This was designated as sample 2.

  In Example 3, the X-ray opaque marker 4 was irradiated with a laser, melted, and adhered to the inner layer 1 and the reinforcing layer 3. At this time, a hole was opened in the radiopaque marker 4 and the radiopaque marker 4 was raised, so that the radiopaque marker 4 was flattened. Thereafter, urethane adhesive was injected into the holes of the X-ray opaque marker 4 to coat the outer layer 1. At this time, the outer layer 1 was bonded to the inner layer 1 via an adhesive injected into the hole of the radiopaque marker 4. This was designated as sample 3.

  In Example 4, the radiopaque marker 4 was notched in advance, and the radiopaque marker 4 was caulked on the outside of the inner layer 1 covered with the reinforcing layer 3. Thereafter, the outer layer 1 was coated. At this time, the outer layer 1 adhered to the inner layer through the hole of the radiopaque marker. This was designated as sample 4.

  In Example 5, the radiopaque marker 4 was adhered to the outside of the inner layer 1 that covered the reinforcing layer 3. Thereafter, the outer layer was coated to obtain Sample 5.

  When the tensile breaking strength was measured for the above samples, Sample 1 to Sample 4 exceeded the tensile breaking strength of Sample 5.

1. Inner layer Outer layer 3. Reinforcing layer 4. X-ray opaque marker 5. Hub 6. Balloon 7. Cutout 11. Lumen 12. Front end opening 13. Proximal end opening 21. catheter

Claims (4)

An inner layer, an outer layer, a reinforcing layer disposed between them, a radiopaque marker disposed at a distal end portion of the catheter, and a hub disposed on the proximal side of the catheter,
At least a part of the radiopaque marker is in close contact with the inner layer and / or the reinforcing layer by melting.   2. The catheter according to claim 1, wherein at least a part of the radiopaque marker has a notch, and the notch is in contact with an inner layer and an outer layer.   The catheter according to claim 1, wherein at least a part of the radiopaque marker has a notch portion, and the notch portion has an inner layer and an outer layer in contact with each other through an adhesive member. A catheter composed of an inner layer, an outer layer, a reinforcing layer disposed between them, a radiopaque marker disposed at a distal end portion of the catheter, and a hub disposed on the proximal side of the catheter. ,
A catheter having a cutout portion in at least a part of the radiopaque marker, wherein the cutout portion is in contact with an inner layer and an outer layer.

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