JP2006149442A - Catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter which reliably reaches a target branching vessel by improving follow-up properties of a catheter to a guide wire in a tubular organ such as a blood vessel and is bent easily by making the distal end soft. <P>SOLUTION: The catheter 19 is equipped with a fluorine resin layer 22 forming an inner periphery, a cylindrical reinforcing body 23 disposed at least on the proximal end side on the outer periphery of the fluorine resin layer 22, and a coated resin layer 26 disposed on the periphery outside of the fluorine resin layer 22 and the reinforcing body 23. The catheter 10 never has the fluorine resin layer 22 on the inner periphery at the distal end part 21, and the diameter is reduced at the distal end part 21 in a tapered manner to reduce the inner diameter. Consequently, a clearance between the inner periphery of the distal end part 22 and the outer periphery of the guide wire becomes small. The following properties to the guide wire is improved since the catheter 10 never causes eccentricity of the guide wire, prevents bumpy movements, is soft, and is easily bent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a medical catheter that is inserted along the outer periphery of a guide wire into a tubular organ of a human body such as a blood vessel, a ureter, a bile duct, and a trachea.

  In recent years, it has been practiced to insert a catheter into a tubular organ such as a blood vessel and administer a drug solution such as a contrast medium or an anticancer drug.

  That is, a thin and flexible guide wire is inserted into the tubular organ in advance, the tip of the guide wire reaches the target location, and the catheter is inserted along the outer periphery of the guide wire to reach the target location. Is pulled out and the catheter is placed in the tubular organ. Then, a chemical solution is injected from the proximal end of the catheter, or a coiled 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. is doing.

  In the following Patent Document 1, in a tube-shaped catheter made of a thermoplastic polymer substance, the insertion side end portion has a shape in which the outer surface is reduced in a rounded corner shape toward the end surface and substantially intersects with the inner surface. There is disclosed a catheter characterized in that the outer surface of the insertion side end is finished with a uniform satin surface with the other outer surfaces of the catheter.

Further, the insertion side end of the catheter is formed as follows. That is, one of a pair of electrodes capable of high-frequency heating is a mold for forming an insertion-side end portion, and a tapered groove in which the distal end of the catheter can be inserted is predetermined in this mold. It is formed with depth. Then, the distal end of the catheter is inserted and pressed into this groove and heated at high frequency to cause heat deformation plasticity according to the groove shape of the mold and stabilize the shape, thereby forming the insertion side end of the catheter. is doing.
Japanese Patent Publication No. 2-28339

  By the way, when the catheter is indwelled at a portion where a blood vessel is branched, there are the following problems. That is, the catheter is inserted along the outer circumference of the guide wire in the blood vessel, but at this time, the distal end of the catheter is caught by the corner of the branch pipe, and the catheter may not reach the target branch pipe. The cause is that the followability of the catheter to the guide wire is poor.

  In the catheter of Patent Document 1, since the entire outer surface of the catheter is finished with a uniform satin surface, for example, when inserting the catheter into a large-diameter tube previously inserted into the blood vessel, The catheter is easy to insert.

  However, the insertion side end portion of the catheter is formed by inserting the distal end of the catheter into a groove formed larger than that and thermally deforming it, and becomes thicker than other portions. It becomes a lack of flexibility. Therefore, when the catheter is inserted into the bent branch portion in the blood vessel, the insertion side end portion is difficult to bend and cannot be smoothly inserted, which causes a problem in the followability of the catheter with respect to the guide wire. Further, when the catheter is inserted into the blood vessel, the inner wall of the blood vessel may be damaged.

  Accordingly, an object of the present invention is to provide a catheter that can improve the followability of the catheter with respect to the guide wire, ensure that the catheter can reach the target branch tube, and can bend easily with a flexible tip. .

In order to achieve the above object, a first aspect of the present invention is a tube-shaped catheter, which is disposed at least on the proximal end side of the fluororesin layer forming the inner circumference and the outer circumference of the fluororesin layer. A cylindrical reinforcing body, and a resin layer coated on the outer periphery of the fluororesin layer and the reinforcing body,
The distal end portion of the catheter is provided with a catheter characterized in that no fluorine-based resin layer is disposed on the inner periphery of the catheter and is tapered so as to narrow the inner diameter.

  According to the first aspect of the invention, since the distal end portion of the catheter is tapered so as to narrow the inner 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 becomes the distal end portion of the catheter. There is less eccentricity and less rattling.

  In addition, the distal end of the catheter is tapered, and the fluorine resin layer is not disposed on the inner periphery, so the distal end is flexible and bends easily without damaging the inner wall of the blood vessel when the catheter is inserted. In addition, it becomes difficult to get caught in the corner of the branch pipe of the blood vessel.

  Thus, by making the tip portion tapered and making the tip portion flexible, the followability of the catheter with respect to the guide wire, in particular, the followability of the catheter with respect to the guide wire at the branching portion of the blood vessel can be improved, The target branch pipe can be surely and smoothly reached.

  In addition, since the inner periphery other than the distal end of the catheter is formed of a fluororesin layer, the friction resistance is lower than that of the outer resin layer, the guide wire is slippery, and the guide wire can be smoothly inserted and removed from the catheter. The operability of the guide wire and catheter can be improved. Furthermore, since a reinforcing body is disposed on the proximal end side of the catheter, torque transmission required for selecting a blood vessel, kink resistance for preventing torsion / bending, and pushability required for insertion are improved.

  Furthermore, since only the distal end portion of the catheter is reduced in diameter, the clearance between the inner circumference of the catheter other than the distal end portion and the outer circumference of the guide wire can be kept moderate, and excessive friction is caused even if the guide wire or the catheter is rotated. Since no resistance is applied, torque transmission can be maintained. In addition, since the inner diameter of the catheter can be kept moderate, the flow rate is not reduced when a drug such as a contrast agent or an anticancer drug is injected.

  According to a second aspect of the present invention, there is provided the catheter according to the first aspect, wherein a slit extending in an axial direction from an end face of the distal end portion is formed in a tapered diameter portion of the distal end portion of the catheter. It is.

  According to the second aspect, since the slit extending in the axial direction from the end surface of the distal end portion is formed in the tapered diameter portion of the distal end portion of the catheter, the distal end portion of the catheter is easily deformed. . Therefore, when a coiled obturator is inserted into the inner circumference of the catheter and pushed out, when the obturator is pushed in, the distal end is pressed from the inner circumference and spreads from the slit. It can be pushed out smoothly without clogging the part, and the obturator can be indwelled at the target location. Further, since the distal end portion is easily deformed by the slit, the flexibility of the distal end portion can be further increased, and the catheter can be more easily inserted.

  According to the catheter of the present invention, since the distal end portion is tapered so as to narrow the inner diameter, the clearance between the inner periphery of the distal end portion and the outer periphery of the guide wire is reduced, the guide wire is not eccentric, and is rattled. It is also more flexible and easier to bend, it does not damage the inner wall of the blood vessel, and it is difficult to get caught in the corner of the branch tube, so the followability of the catheter to the guide wire can be improved, and the target branch tube can be reliably and smoothly Can be reached.

  In addition, since the inner circumference of the catheter is formed of a fluororesin layer, the guide wire can be easily slipped in and out, and a reinforcing body is disposed on the proximal end side, so that the pushability of the catheter, etc. To improve.

  Furthermore, since only the distal end portion is reduced in diameter, the clearance between the catheter inner periphery other than the distal end portion and the guide wire outer periphery can be maintained appropriately, torque transmission can be maintained, and the flow rate of the drug is not reduced.

  Hereinafter, an embodiment of the catheter of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the catheter 10 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 (PP) or nylon, and has a flat shape so that it can be easily grasped by hand. Further, the catheter hub 30 has an introduction tube 31 communicating 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 later-described guide wire 40 or coil-shaped obturator 41 into the main body of the catheter 20.

  Referring also to FIG. 2, the catheter body 20 has a tube shape extending with a constant outer diameter, the proximal end is connected to the catheter hub 30, and the distal end portion 21 having a tapered diameter is formed at the distal end. ing. The catheter body 20 has a multilayer structure in which a plurality of layers are stacked.

  Specifically, on the inner periphery, for example, polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene A tubular fluorinated resin layer 22 made of a copolymer (ETFE) or the like is disposed. The fluorine resin layer 22 has a higher melting point than a resin layer 26 described later.

  A cylindrical reinforcing body 23 is arranged on the outer periphery of the fluororesin layer 22 and 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. It consists of a so-called braided shape, a coil or the like.

  Further, a metal coil 24 is disposed on the distal end portion 21 side of the catheter body 20 on the outer periphery of the fluororesin layer 22. The metal coil 24 is made of a metal wire, and is preferably a radiopaque material from the viewpoint of a marker at the time of X-ray contrast. For example, Au, Pt, Ag, Bi, W, Alternatively, an alloy containing these metals is preferably used. The metal coil 24 ensures flexibility at the distal end of the catheter 10 and shape recovery.

  Moreover, you may use the wire which coat | covered the superelastic alloy on the core wire which consists of a radiopaque material. According to this, the metal coil which has the softness | flexibility by a superelastic alloy, and the visibility by a radiopaque material is obtained.

  Further, an annular marker 25 made of a radiopaque material is provided near the distal end of the catheter body 20. Therefore, the position when the catheter 10 is inserted can be visually recognized by an X-ray monitor or the like. As the marker 25, for example, a metal such as Pt, Pt alloy, W, Au plated W, Au or the like is preferably used. In addition, it is preferable that this marker 25 is arrange | positioned 0.5-2.0 mm away from the front end surface of the catheter main body 20 (it is set as the distance F), and this ensures the marker effect | action at the time of X-ray imaging. .

A tubular resin layer 26 is coated on the outer periphery of the fluorine resin layer 22, the reinforcing body 23, the metal coil 24, and the marker 25. As the resin layer 26, for example, a heat-shrinkable synthetic resin such as polyurethane, nylon elastomer, polyether block amide, polyethylene, polyvinyl chloride, and vinyl acetate is used. Moreover, the resin layer 26 may contain X-ray opaqueness by containing powders such as BaSO ₄ , Bi, and W.

  Further, on the outer periphery of the resin layer 26, 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 and 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.

  And the front-end | tip part 21 of the resin layer 26 which comprises the catheter main body 20 is diameter-reduced gradually so that an internal diameter may also narrow toward an end surface, and has comprised the taper shape. The thickness of the tip 21 is equal to or thinner than the thickness of the resin layer 26. As shown in FIG. 2, the tip portion 21 is formed of only the resin layer 26, and the fluorine-based resin layer 22 is not disposed on the inner peripheral surface. The tip portion 21 reduces the clearance with respect to the outer periphery of the guide wire 40. In this case, the inner diameter D of the distal end portion 21 is preferably a clearance of 0.01 to 0.2 mm with respect to the outer periphery of the guide wire 40.

  In addition, 0.5-5.0 mm is preferable and, as for the length C of the axial direction of this front-end | tip part 21, 0.8-2.0 mm is more preferable.

  In addition, in order to further increase the flexibility of the distal end portion 21, a slit 21a extends in the same direction as the axial direction. In this embodiment, the distal end surface of the catheter body 20 gradually increases from the distal end surface toward the proximal end. It has a wedge shape with a narrow width. In addition, although not shown, the slits 21a are formed at four locations at equal intervals in the circumferential direction, and are formed in a cross shape when viewed from the axial direction. In the case of this embodiment, the slit 21a is provided in the same direction as the axial direction. However, for example, the slit 21a may be provided obliquely with respect to the axial direction and can be selected as appropriate. The length E of the slit 21a is preferably 0.1 to 2.0 mm.

  Next, an example of the manufacturing method of the catheter 10 of the present invention will be described.

  First, a tubular fluororesin layer 22 is formed by immersing a wire in a molten fluororesin, heating the wire with a fluororesin having a predetermined thickness, and then pulling out the core wire. To do.

  Then, with the mandrel inserted in the inner periphery of the fluororesin layer 22, the reinforcing body 23 is knitted into a braided shape with a stainless wire or the like from the base end to the middle in the axial direction on the outer periphery of the fluororesin layer 22. wear.

  Next, the metal coil 24 is covered from the tip of the fluorine-based resin layer 22 so as not to overlap the reinforcing body 23 and disposed in front of it. Further, the marker 25 is put on the tip of the fluorine-based resin layer 22 so as not to overlap the metal coil 24.

  Then, a heat-shrinkable tubular resin layer 26 having an inner diameter larger than the outer diameter of the marker 25, the metal coil 24, and the reinforcing body 23 is placed on the outer periphery of the marker 25, the metal coil 24, and the reinforcing body 23. At this time, the tip of the resin layer 26 is placed so as to protrude from the tip of the fluororesin layer 22.

  Then, the resin layer 26 is heated and contracted by heating means such as a heater so that the resin layer 26 is attached to the outer periphery of the marker 25, the metal coil 24, the reinforcing body 23, and the fluorine-based resin layer 22. . The fluorine-based resin layer 22 has a melting point higher than that of the resin layer 26 and therefore does not melt at the melting temperature.

  At this time, since the fluorine-based resin layer 22 is not disposed on the inner periphery of the tip of the resin layer 26, only the resin layer 26 covered on the outer periphery is thermally contracted to reduce the diameter in a taper shape and the tip portion 21. Is formed, and the catheter body 20 shown in FIG. 2 is formed.

  In addition, you may coat | cover the tube which consists of a some resin layer instead of the single resin layer 26. FIG. For example, the base end side is coated with a hard resin layer, the soft resin layer is coated adjacent to the base resin, and the soft resin layer is further coated adjacent to the soft resin layer. You may coat the resin layer in which hardness becomes soft in steps. If it is moistened, the hardness of the catheter body 20 gradually becomes softer toward the tip, and the hardness gradient can be smoothed, so that the kink resistance and pushability of the catheter can be improved.

  Further, 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 26.

  Then, the distal end of the catheter hub 30 is inserted and attached to the proximal end of the catheter body 20, and the catheter 10 is formed by protecting the connecting portion by the protective tube 32.

  Next, a method for using the catheter 10 of the present invention and its effects will be described with reference to FIGS. 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 into the blood vessel 1, and the catheter 10 is inserted along the outer periphery of the guide wire 40. Alternatively, when the guide wire 40 is inserted from the introduction tube 31 of the catheter hub 30 and the distal end of the guide wire 40 is slightly advanced in a state where the catheter 10 is disposed on the outer periphery of the guide wire 40, the catheter 10 is caused to follow. The catheter 10 may be advanced by repeating the operation of advancing.

  When the guide wire 40 reaches the branch portion of the blood vessel 1, the distal end portion of the guide wire 40 is advanced to the target branch tube 2. Next, the catheter 10 of the present invention is advanced along the outer periphery of the guide wire 40.

  At this time, since the distal end portion 21 of the catheter 10 is tapered so as to narrow the inner diameter, the clearance between the inner periphery of the distal end portion 21 and the outer periphery of the guide wire 40 is reduced as shown in FIG. Therefore, the guide wire 40 is not eccentric at the distal end portion 21 of the catheter 10 and is less likely to be rattled.

  Moreover, since the distal end portion 21 of the catheter 10 is tapered and the fluorine resin layer 22 is not disposed on the inner periphery, the distal end portion 21 becomes flexible and is easily bent. Therefore, when the catheter 10 is advanced in the blood vessel 1, the inner wall of the blood vessel is not damaged and it is difficult to get caught in the corner of the branch tube 2 of the blood vessel.

  As described above, according to the catheter 10 of the present invention, the distal end portion 21 is tapered and the distal end portion 21 is flexible, so that eccentricity and rattling of the guide wire 40 is suppressed and bending is facilitated. Therefore, the followability of the catheter 10 with respect to the guide wire 40 can be improved.

  In particular, as shown in FIG. 5, when the catheter 10 is made to follow the guide wire 40 at the branch portion of the blood vessel, the distal end portion 21 is hardly caught by the corner portion of the branch tube 2. Since the portion 21 is formed in a tapered shape and can be advanced so as to slip through the corner portion of the branch pipe 2, the target branch pipe 2 can be reliably and smoothly reached.

  By the way, the fluorine resin layer 22 is generally known to have a low frictional resistance. In the catheter 10 of the present invention, since the inner periphery other than the distal end portion 21 is formed of the fluorine resin layer 22, the friction resistance is lower than that of the resin layer 26 coated on the outer periphery, and the guide wire 40 slips. The guide wire 40 can be inserted and removed smoothly from the catheter 10 and the operability of the guide wire 40 and the catheter 10 can be improved. In addition, since the reinforcing body 23 is disposed on the proximal end side of the catheter 10, the torque transmission required for selecting a blood vessel, the kink resistance for preventing torsion / bending, and the pushability required for insertion are improved.

  Furthermore, since only the distal end portion 21 of the catheter 10 is reduced in diameter, the clearance between the inner periphery of the catheter 10 other than the distal end portion 21 and the outer periphery of the guide wire 40 can be kept moderate (see FIG. 3). Therefore, even if it is going to rotate the guide wire 40 or the catheter 10, since excessive frictional resistance is not mutually applied, torque transmission property can be maintained. In addition, since the inner diameter of the catheter 10 can be kept moderate, the flow rate is not reduced when a drug such as a contrast medium or an anticancer drug is injected.

  Moreover, since the slit 21a extending in the axial direction from the end surface of the distal end portion 21 is formed in the tapered portion of the distal end portion 21 of the catheter 10, the distal end portion of the catheter 10 is easily deformed. Therefore, as shown in FIG. 4, the effect is exhibited when a coiled obturator 41 is inserted into the inner periphery of the catheter 10 and pushed out. That is, when the obturator 41 is pushed in, the distal end portion 21 is pressed from the inner periphery thereof and spreads from the slit 21a. Accordingly, the obturator 41 can be pushed out smoothly without clogging the distal end portion 21, and the obturator 41 can be placed at a target location. The same effect can be obtained not only in the coil-shaped obturator 41 but also when using a guide wire of a type in which a coil is mounted on the outer periphery of the core wire. Further, since the distal end portion 21 is easily deformed by the slit 21a, the flexibility of the distal end portion 21 can be further increased, and the catheter 10 can be easily inserted into the blood vessel.

  In order to confirm followability and flexibility of the catheter 10 of the present invention with respect to the guide wire 40, the following test was performed. The following Examples 1 and 2 and Comparative Example 1 were produced as the test pieces.

Example 1
First, polytetrafluoroethylene (PTFE) was dissolved, and a wire rod having a predetermined length was dipped therein and heated, and then the core wire was pulled out to form a tube-shaped fluororesin layer 22.

  Next, a mandrel was inserted into the inner periphery of the fluorine-based resin layer 22, and a stainless steel wire was used around the outer periphery of the fluorine-based resin layer 22, and was knitted to a length of 1500 mm from the base end.

  And from the front-end | tip of the fluorine-type resin layer 22, the metal coil 24 made from a Ni-Ti alloy was arrange | positioned so that it might not overlap with the reinforcement body 23. FIG.

  Further, the marker 25 is arranged so as not to overlap the metal coil 24 from the tip of the fluorine-based resin layer 22.

  Next, a resin layer 26 made of a nylon tube was placed on the outer periphery of the marker 25, the metal coil 24, and the reinforcing body 23. The tip of the resin layer 26 was put on the tip of the fluororesin layer 22 so as to protrude.

  And the resin layer 26 outer periphery was heated with heating means, such as a heater. Then, the resin layer 26 thermally contracted, and was attached to each of the marker 25, the metal coil 24, the reinforcing body 23, and the fluorine-based resin layer 22. The tip of the resin layer 26 was reduced in diameter so that only the outer peripheral resin layer 26 narrowed the inner diameter, and the tapered tip portion 21 was formed.

  Next, four places in the circumferential direction of the tip 21 were cut with a razor, and the slit 21a was formed in a cross shape when viewed from the axial direction.

  Thus, the catheter of Example 1 was produced.

  At this time, the inner diameter A of the catheter is 0.55 mm, the outer diameter B is 0.75 mm, the length C of the distal end portion 21 is 1.0 mm, the inner diameter D of the distal end portion 21 is 0.5 mm, and the length E of the slit 21a. Was 0.5 mm, and the distance F from the tip 21 to the marker 25 was 1.5 mm.

Example 2
In the catheter of Example 1, a catheter similar to Example 1 was prepared except that the slit 21a was not provided at the distal end portion 21.

Comparative Example 1
In the catheter of Example 1, a catheter similar to Example 1 was produced except that the tapered tip portion 21 and the slit 21a were not provided.

  The following tests were performed on the various catheters produced as described above.

Test 1
Various catheters were tested for followability to guide wires.

  A blood vessel model 100 shown in FIG. 6 was prepared. The blood vessel model 100 has a straight passage 101, and a branch passage 102 is formed inclined at an angle of 45 degrees with respect to the passage 101. At this time, the width of the passage 101 was 3.0 mm, and the width of the branch path 102 was 1.0 mm.

  The blood vessel model 100 was then filled with distilled water. In this state, the guide wire 40 is inserted from the start end of the passage 101 (right side in FIG. 6), and if the guide wire 40 is inserted into the branch path 102, the catheter can smoothly follow and advance to the branch path 102. I confirmed that I could do it. In this case, the insertion length of the distal end of the guide wire 40 with respect to the branch path 102 is X mm. The results are shown in Table 1. In this case, the smaller the insertion length X, the higher the followability of the catheter with respect to the guide wire.

  The guide wire 40 used at this time had an outer diameter of 0.41 mm. Therefore, the clearance between the inner periphery of the distal end portion 21 of the catheter of Examples 1 and 2 and the guide wire 40 is 0.045 mm (when the guide wire 40 is located at the center of the catheter). On the other hand, the clearance between the inner circumference of the catheter of Comparative Example 1 and the guide wire 40 is 0.07 mm (when the guide wire 40 is located at the center of the catheter).

  As shown in Table 1, the catheter of Comparative Example 1 whose tip was not reduced in diameter could not follow the catheter unless the guide wire 40 was inserted as much as 20 mm. On the other hand, in the catheters of Examples 1 and 2 in which the distal end portion 21 has a tapered diameter, the catheter can be tracked by inserting only 5 to 10 mm, and the followability of the catheter to the guide wire is ensured. It was confirmed that it was improved.

Test 2
Various catheters were tested for flexibility at the tip.

As shown in FIG. 7, this flexibility test is performed by preparing a stainless steel plate 110 having a predetermined thickness and having a catheter fixing hole 111 at the center, inserting various catheters into the hole 111, Was fixed by protruding 5 mm from the plate 110. The resistance load when the stainless steel pressing head 112 is pushed 0.5 mm at a speed of 10 mm / min and 0.3 mm at a speed of 10 mm / min along the direction of the arrow in FIG. The maximum value (abutting maximum load) was measured. This was done three times for each type of catheter. The results are shown in Table 2. In this case, it means that the smaller the resistance load, the higher the flexibility of deformation.

  As shown in Table 2, it can be seen that Comparative Example 1 in which the tip is not reduced in diameter has a large resistance load of the guide wire 40 and lacks flexibility. On the other hand, it can be understood that the resistance load is small and flexible in the case of Example 2 in which the tip 21 has a tapered diameter. Furthermore, in the case of Example 2 in which the tip 21 was tapered and the slit 21a was provided, it was confirmed that the resistance load was smaller and more flexible than Example 2.

  INDUSTRIAL APPLICABILITY The present invention improves the followability of a catheter with respect to a guide wire in a tubular organ such as a blood vessel, can reliably reach the target branch tube, and is used as a flexible catheter with a flexible tip. can do.

It is a perspective view which shows one Embodiment of the catheter of this invention. It is sectional drawing in the tip vicinity of the catheter. It is sectional drawing which shows the state at the time of making it follow a guide wire using the catheter. It is sectional drawing which shows the state at the time of pushing out a coil-shaped obturator using the catheter. It is explanatory drawing which shows the state which used the catheter in the branch part of the blood vessel. It is explanatory drawing which shows the method of the follow-up test of various catheters. It is explanatory drawing which shows the method of the softness | flexibility test of various catheter tips.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Catheter 20 The catheter main body 21 The front-end | tip part 21a Slit 22 Fluorine-type resin layer 23 Reinforcement body 24 Coil 25 Marker 26 Resin layer 30 Catheter hub 31 Introducing tube 32 Protective tube 40 Guide wire

Claims (2)

A tube-shaped catheter, a fluorine-based resin layer that forms an inner periphery, a cylindrical reinforcing body that is disposed at least on the proximal side on the outer periphery of the fluorine-based resin layer, the fluorine-based resin layer, and the A resin layer coated on the outer periphery of the reinforcing body;
The catheter is characterized in that the distal end portion of the catheter is not provided with a fluorine-based resin layer on the inner periphery thereof, and is reduced in a taper shape so as to narrow the inner diameter.   The catheter according to claim 1, wherein a slit extending in an axial direction from an end face of the distal end portion is formed in a tapered diameter portion of the distal end portion of the catheter.

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