JP4790349B2 - catheter - Google Patents

Description

  The present invention relates to a catheter used for indwelling a chemical solution such as an anticancer drug, indwelling a blood vessel obturator, or the like, or for penetrating a stenosis, by continuously or temporarily indwelling in a tubular organ such as a blood vessel.

  In recent years, a catheter is inserted into a tubular organ such as a blood vessel to administer a chemical solution such as an anticancer agent, or a coiled vascular occlusion device is placed through the catheter.

  That is, after a thin and flexible guide wire is inserted into a tubular organ such as a blood vessel in advance, the tip of the guide wire reaches the target location, and a catheter is inserted along the outer periphery of the guide wire to reach the target location. The guide wire is withdrawn and the catheter is placed in the tubular organ. Then, a chemical solution is injected from the proximal end of the catheter, or a blood vessel obturator is placed in the tubular organ through the catheter, and one of the branch pipes of the tubular organ is blocked to effectively administer the chemical solution. ing.

As such a catheter, for example, Patent Document 1 below discloses a medical catheter in which a plurality of radiographic contrastable labels are formed using a radiographic contrast material.
Japanese Utility Model Publication No. 5-48953

  As in the above Patent Document 1, by attaching a plurality of radiocontrastable markers (hereinafter simply referred to as “markers”) to the catheter at a predetermined interval, the catheter inserted into the body from the distance between the markers by radiography is used. The position can be confirmed, the size of a blood clot, tissue in the body, and the like can be grasped, and the necessary dose of the drug solution can be optimized.

  However, in Patent Document 1, a marker is formed by embedding or applying a radiographic contrast material on the surface of the catheter. When the marker is formed in this way, the number of markers can be increased, If the pitch interval is narrowed, it takes time and effort. In addition, even if the marker can be visually recognized, the shape of the catheter cannot be visually recognized. Therefore, when inserting into a site where blood vessels or the like are bent and bent, the shape cannot be grasped, so that the insertion property tends to be inferior. Furthermore, the distal end portion of the catheter is usually elastic because it requires running properties and operability, but there is a difference in elasticity between the radiographic material and the catheter material. Buckling may occur at the interface between the material and the catheter material.

  Accordingly, an object of the present invention is to provide a catheter that can accurately grasp the insertion state of the catheter in the body, measure the size of the tissue and the like, hardly buckle, and has excellent productivity.

In order to achieve the above object, the present invention is a tube-shaped catheter, comprising a fluorine-based resin layer forming an inner periphery, and a reinforcing braid disposed at least on the outer periphery of the base end of the fluorine-based resin layer. A coil disposed on the outer periphery of the front end of the fluororesin layer and a resin layer disposed on the outermost periphery, and the coil includes a radiopaque wire having a narrow pitch interval and a wide width. And two or more portions having a narrow pitch interval are provided at a predetermined interval, and the wire of the wire constituting the coil is provided at the most distal end portion of the coil. A coil smaller than the outer diameter of the coil is further disposed, and the most distal portion of the catheter has no fluorine resin layer disposed on the inner periphery thereof. And arranged on the outermost periphery Serial resin layer is to provide a catheter which is reduced in diameter in a tapered shape so as to narrow the inner diameter.

According to the above invention , the radiopaque wire rod having a narrow pitch interval portion and a wide portion at the distal end portion of the catheter, and two or more narrow pitch interval portions are provided at a predetermined interval. Since the coil consisting of the above is installed, a portion with a narrow pitch interval appears dark, and a portion with a wide pitch interval appears slightly due to radiography, resulting in a contrast. Therefore, it is possible to accurately grasp the insertion state of the catheter in the body, and this dark portion (the portion with a narrow pitch interval) can be used as a scale, so the length of tissue in the body and the distance to the target location It is possible to easily adjust the amount of a necessary chemical solution according to the size of a blood clot or the like, or to easily place a blood vessel obturator or the like at a desired position. Furthermore, flexibility as a coil is imparted by a portion having a wide pitch interval, excellent in route selectivity at a branching portion such as a blood vessel, and a catheter can be easily introduced at a predetermined location. And the said coil can adjust the number of scales (the number of parts with a narrow pitch interval) and the scale width (the width of a part with a narrow pitch interval) suitably by changing the winding method of a coil suitably, and it is in production workability. Since it is excellent and is obtained by processing a continuous wire, buckling hardly occurs and kink resistance is also excellent.

In addition, since the outer diameter of the coil disposed on the most distal end side is smaller than the outer diameter of the coil located on the proximal end side, it is easy to insert into the body and is excellent in running performance in the body.

Further, since the distal end portion of the catheter is reduced in diameter, the clearance between the inner periphery of the distal end portion and the outer periphery of the guide wire is reduced, and the guide wire is not eccentric at the distal end portion of the catheter, and rattling can be suppressed. . In addition, since the fluorine-based resin layer is not disposed on the inner periphery of the tip portion reduced in the taper shape, the tip portion is flexible and easily bent. For this reason, the inner wall of the blood vessel or the like is not damaged when the catheter is inserted, and it is difficult to get caught in the corner of the branching portion of the blood vessel or the like. Furthermore, since the clearance between the inner circumference of the catheter other than the tip and the outer circumference of the guide wire can be kept moderate, excessive frictional resistance is not applied even if the guide wire or the catheter is rotated. Can be maintained.

  According to the catheter of the present invention, a portion where the coil pitch interval is narrow appears dark, and a portion where the coil pitch interval is wide appears slightly due to radiography, resulting in a contrast. Therefore, it is possible to accurately grasp the insertion state of the catheter in the body, and this dark portion (the portion with a narrow pitch interval) can be used as a scale, so the length of tissue in the body and the distance to the target location Furthermore, flexibility as a coil is imparted by a portion having a wide pitch interval, excellent route selectivity at a branching portion such as a blood vessel, and the catheter can be easily introduced at a predetermined location. In addition, by appropriately changing the winding method of the coil, the number of scales (number of narrow pitch intervals) and scale width (width of narrow pitch intervals) can be adjusted as appropriate. . And since it is what processed the continuous wire, it is hard to produce buckling and is excellent also in kink resistance.

1 to 3 show a reference catheter for understanding the catheter of the present invention.

As shown in FIG. 1, the catheter 10 of this reference example includes a catheter main body 20 having a tube shape and a catheter hub 30 connected to the proximal end of the catheter main body 20.

  The catheter hub 30 is made of a synthetic resin such as polypropylene or nylon, and has a flat shape so that it can be easily grasped by hand. The catheter hub 30 has an introduction tube 31 that communicates with the catheter body 20. The introduction tube 31 has an inner diameter that tapers toward the opening, and serves as a guide for introducing a guide wire 40 and the like described later into the catheter body 20.

  The catheter body 20 has a tubular shape, and the proximal end is connected to the catheter hub 30. The catheter body 20 has a multilayer structure in which a plurality of layers are stacked.

  Referring also to FIG. 2, on the inner periphery of the catheter body 20, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP) A tubular fluorine resin layer 22 made of a fluorine resin such as tetrafluoroethylene-ethylene copolymer (ETFE) is disposed. The fluorine resin layer 22 has a higher melting point than a resin layer 25 described later.

  A cylindrical reinforcing body 23 is disposed on the outer periphery of the fluororesin layer 22 on the proximal end side of the catheter body 20. As the reinforcing body 23, for example, a metal wire made of a metal such as stainless steel, W, W plated with Au, or a Ni—Ti alloy, or a wire made of a synthetic resin such as nylon or polyester is alternately crossed. A so-called braided shape is used.

  Furthermore, a coil 24 is disposed on the distal end 21 side of the catheter body 20 on the outer periphery of the fluororesin layer 22.

  The coil 24 is made of a radiopaque wire, has a portion A with a narrow pitch interval and a portion B with a wide pitch interval, and has two or more portions A with a narrow pitch interval at a predetermined interval. Have.

  The wire of the coil 24 is not particularly limited as long as it is made of a radiopaque wire, for example, a wire made of a radiopaque material such as Au, Pt, Pd, W, and alloys thereof, Shape memory alloys such as Ni-Ti alloys, Ni-Ti-X (X = Fe, Cu, V, Co, etc.) alloys, Cu-Zn-X (X = Al, Fe, etc.) alloys, stainless steel, etc., Au, Examples thereof include wires obtained by plating Pt, Pd, W, and alloys thereof.

  The total length of the coil 24 is preferably 10 to 100 mm. If it is less than 10 mm, the measurement action by the marker at the time of radiography is weak, which is not preferable. Moreover, when it exceeds 100 mm, workability | operativity at the time of manufacture deteriorates and it becomes impossible to measure with a marker.

  The coil pitch of the portion A having a narrow pitch interval is preferably less than 100% and more preferably 0 to 30% with respect to the coil wire diameter. If the coil pitch exceeds 100% with respect to the coil wire diameter, the marker action at the time of radiographic imaging becomes weak, which is not preferable.

  100% or more is preferable with respect to a coil wire diameter, and the coil pitch of the part B with a wide pitch space | interval has more preferable 300 to 500%. When the coil pitch is less than 100% with respect to the coil wire diameter, the marker action at the time of radiographic imaging becomes strong, the difference in contrast with the coil A portion does not occur, and the measurement function becomes weak.

The length L _A of the portion A having a narrow pitch interval is preferably 0.5 to 10 mm, and more preferably 0.05 to 1.0 mm. When the length L _A is greater than 10 mm, the elasticity inferior prone as a coil, when inserted, such as into a blood vessel, a tend to damage the inner wall of the blood vessel, when radiation imaging is less than 0.5mm This is not preferable because the marker action becomes weak.

  Since the coil 24 is entirely composed of a radiopaque wire, the shape of the coil in the body can be confirmed by radiography and the running state can be grasped. In addition, since the contrast between the portion A having a narrow pitch interval and the portion B having a wide pitch interval is generated, the length A of the body in the body and the distance to the target location can be measured using the portion A having the narrow pitch interval as a marker.

Further, in the catheter 10, the distal end side of the coil 24, which is constituted further small wire of wire diameter than the wire of the coil 24, that have a small coil 24a is attached than the outer diameter of the coil 24. By attaching the coils 24a, insertability into the body is improved since so that the tip is reduced in diameter. Thus, in this catheter 10 , a plurality of coils having a narrow pitch portion and a wide portion can be used.

  A tubular resin layer 25 is coated on the outer periphery of the fluorine resin layer 22, the reinforcing body 23, and the coil 24. As the resin layer 25, for example, a heat-shrinkable synthetic resin such as polyurethane, nylon elastomer, polyether block amide, polyethylene, polyvinyl chloride, and vinyl acetate is used.

  Further, on the outer periphery of the resin layer 25, for example, polyvinyl pyrrolidone, polyethylene glycol is used on the outer periphery of the catheter main body 20 so as to improve the lubricity of the catheter main body 20 with respect to the inner wall of the blood vessel or to prevent the thrombus from adhering as much as possible. It is preferable that a hydrophilic resin such as methyl vinyl ether maleic anhydride copolymer is coated.

Next, an example of a method of manufacturing the catheters 10.

  First, the coil 24 is formed. That is, a continuous radiopaque wire is wound so as to have a narrow pitch portion A and a wide portion B, and at this time, the narrow pitch portion is provided so as to be arranged at a predetermined interval. In addition, in order that the part B with a narrow pitch interval may have a function as a scale and improve visibility, it is preferable that the part B with a narrow pitch interval is a close winding.

  Next, the core wire is immersed in the melted fluororesin and pulled up, so that the outer periphery of the core wire is covered with a fluororesin having a predetermined thickness to form a tube. Then, the tube-like fluorine-based resin layer 22 is formed by heating and extracting the core wire, and the mandrel is inserted into the inner periphery of the fluorine-based resin layer 22 in the axial direction from the proximal end of the outer periphery of the fluorine-based resin layer 22. Halfway through, the reinforcing body 23 is knitted into a braided shape with a stainless steel wire or the like. In addition, the coil 24 is attached to the tip of the fluororesin layer 22.

  Then, the outer periphery of each member of the reinforcing body 23 and the coil 24 is covered with a heat-shrinkable tube-shaped resin layer 25, and the resin layer 25 is heated and contracted by heating means such as a heater, whereby the resin layer 25 Is attached to the outer periphery of the reinforcing body 23 and the coil 24.

  Note that the fluorine-based resin layer 22 has a higher melting point than the resin layer 25, and therefore does not melt when the resin layer 25 is heated.

  In addition, only the distal end portion 21 of the catheter body 20 may be covered with another resin layer, for example, a more flexible resin layer than the resin layer 25.

  When the resin layer 25 is deposited, the mandrel is extracted, and the distal end of the catheter hub 30 is inserted and connected to the proximal end of the catheter body 20. It is formed.

Next, an example of a method of using the catheters 10, and, for its operation and effect will be described with reference to FIG. As the guide wire 40 used at this time, various known ones can be used. That is, a superelastic alloy, a core wire made of stainless steel, etc., coated with a synthetic resin film, a coil attached to the outer periphery of the core wire, and the outer periphery of this coil further covered with a synthetic resin film, etc. are used.

  First, the guide wire 40 is inserted from the introduction tube 31 of the catheter hub 30, the guide wire 40 is inserted into the blood vessel 1, and the catheter 10 is moved along the outer periphery of the guide wire 40.

  In the insertion operation of the catheter 10, when the guide wire 40 reaches the branch portion of the blood vessel 1, the tip of the guide wire 40 is moved to the target branch tube 2. At this time, the guide wire 40 is bent according to the bent shape of the branch pipe 2. Next, the catheter 10 of the present invention is moved along the outer periphery of the guide wire 40 to guide the distal end portion of the catheter 10 into the branch tube 2.

In this case, the catheter 10, the distal end, the coil 24 formed of continuous wire is attached, the guide to move the catheter 10 along the outer periphery of the wire 40, also pushes the catheter 10, the distal end 21 bends flexibly in accordance with the bent shape of the blood vessel 1 and the angle of the branch tube 2, and does not cause buckling because there is no boundary portion where the bending strength is clearly different.

  Further, the catheter 10 bends while keeping the inner diameter of the distal end portion 21 substantially constant, and the inner diameter of the distal end portion 21 is not narrowed, and the slidability of the catheter 10 with respect to the guide wire 40 is maintained well. Thus, the followability of the catheter 10 with respect to the guide wire 40 in the branch pipe 2 of the blood vessel 1 can be effectively improved, and the target branch pipe can be reliably and smoothly reached.

  Furthermore, since the lumen of the distal end portion 21 of the catheter 10 is not narrowed, a drug solution or the like can be reliably administered. Further, since the distal end portion 21 of the catheter 10 is gradually small and flexible toward the forefront, it does not damage the inner wall of the blood vessel 1 when the catheter 10 is inserted, and abuts against the corner portion of the branch tube 2. Even if it abuts against the inner wall of the branch pipe 2, they will not be damaged.

  Further, since the inner circumference of the catheter 10 is made of the fluorine-based resin layer 22 having a small friction coefficient, the guide wire 40 is easily slipped in the catheter 10, and the guide wire 40 can be smoothly inserted and removed from the catheter 10. The operability of the wire 40 and the catheter 10 can be improved.

  Furthermore, since the reinforcing body 23 is disposed on the outer periphery of the proximal end portion of the fluororesin layer 22, that is, on the proximal end portion side of the catheter 10, the kink resistance on the proximal end portion side of the catheter 10 can be improved. In addition, torque transmission required for selecting a blood vessel and pushability when the catheter 10 is pushed in can be improved.

  And when performing radiography, the shape of the catheter in the body can be grasped by the contrast between the portion A with a narrow pitch interval of the coil 24 and the portion B with a wide pitch interval, and the portion A with a narrow pitch interval can be used as a marker. The size of the thrombus 3 and the distance to the target can be accurately measured. Therefore, the required amount of the necessary chemical solution can be grasped, and the blood vessel obturator and the like can be accurately placed at the target location.

An embodiment of the catheter of the present invention will be described based on FIG. It should be noted that substantially the same parts as those in the reference example are denoted by the same reference numerals and description thereof is omitted.

This embodiment is different from the reference example in that the distal end portion 21a of the resin layer 25 constituting the catheter body 20 is gradually reduced in diameter so as to narrow the inner diameter toward the end surface.

  The catheter body 20 can be manufactured as follows, for example.

After attaching the reinforcing body 23 and the coil 24 to the outer periphery of the fluorine-based resin layer 22 as in the above-described reference example , the tip of the resin layer 25 protrudes from the tip of the fluorine-based resin layer 22 to the outer periphery of each of these members. It can be manufactured by heating the resin layer 25 by heating means such as a heater. That is, since the fluororesin layer 22 is not disposed on the inner periphery of the distal end of the resin layer 25, only the resin layer 25 is thermally contracted to reduce the diameter to a taper shape, and the catheter body 20 shown in FIG. It is formed.

  In this case, it is preferable that the thickness of the distal end portion 21a is equal to or thinner than the thickness of the resin layer 25. Moreover, it is preferable that the internal diameter D of the front-end | tip part 21a is 0.1-0.2 mm clearance with respect to the guide wire 40 outer periphery. Moreover, 0.5-5.0 mm is preferable and, as for the length L of the axial direction of the front-end | tip part 21a, 0.8-2.0 mm is more preferable.

According to the catheter of the implementation form of this, since the reduced diameter tip portion 21a of the catheter body 20, the clearance between the inner circumference and the guide wire outer peripheral tip portion smaller, the guide wire is eccentric at the distal end of the catheter There is no shakiness. Further, since the fluororesin layer 22 is not disposed on the inner periphery of the distal end portion 21a, it is flexible and easily bent. For this reason, the inner wall of the blood vessel or the like is not damaged when the catheter is inserted, and it is difficult to get caught at the corner of the branching portion of the blood vessel or the like. And since the clearance between the catheter inner periphery and the guide wire outer periphery other than the tip can be kept moderate, excessive frictional resistance is not applied even if the guide wire or catheter is rotated, and torque transmission is maintained. it can.

  INDUSTRIAL APPLICATION This invention can be utilized as a catheter which can administer a chemical | medical solution etc. efficiently in tubular organs, such as a blood vessel, or can place a vascular obturator.

It is a perspective view which shows the catheter of a reference example when understanding the catheter of this invention. It is sectional drawing in the tip part vicinity of the catheter. It is a perspective view of the tip part vicinity of the catheter. FIG. 2 is a cross-sectional view of the catheter according to an embodiment of the present invention, in the vicinity of the distal end portion of the catheter. It is the state figure used in the blood vessel bifurcation part of the catheter.

Explanation of symbols

1: Blood vessel 2: Branching tube 3: Thrombus 10: Catheter 20: Catheter body 21, 21a: Tip portion 22: Fluorine-based resin layer 23: Reinforcing body 24, 24a: Coil 25: Resin layer 30: Catheter hub 31: Introduction tube 32: Protection tube 40: Guide wire

Claims (1)

A tubular catheter,
A fluorine-based resin layer forming an inner periphery, a reinforcing braid disposed at least on the outer periphery of the base end of the fluorine-based resin layer, a coil disposed on the outer periphery of the distal end of the fluorine-based resin layer, and an outermost periphery And a resin layer disposed on the
The coil is formed by winding a radiopaque wire so as to have a narrow pitch interval portion and a wide pitch interval portion, and two or more narrow pitch interval portions are provided at a predetermined interval. and,
A coil that is thinner than the wire diameter of the wire constituting the coil is further disposed at the most distal portion of the coil, and a coil that is smaller than the outer diameter of the coil is further disposed.
The distal end portion of the catheter has no fluorine resin layer disposed on the inner periphery thereof, and the resin layer disposed on the outermost periphery is reduced in a taper shape so as to narrow the inner diameter. A catheter characterized by.

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