JP2005312726A - Catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter which surely reaches a target branching vessel and can be easily inserted even to a narrow blood vessel, by improving the follow-up property of the catheter to a guide wire in the branching part of a blood vessel. <P>SOLUTION: For the catheter 10, a distal end part 21 is in the shape of being obliquely cut and the shorter peripheral wall 21a of the distal end part 21 is formed harder than the other part. Thus, since it is bent with such directivity that the longer peripheral wall 21b of the distal end part 21 becomes the inner side and the shorter peripheral wall 21a becomes the outer side, when the catheter 10 is inserted at the branching part of the blood vessel, it is bent while the longer peripheral wall 21b is on the inner side and the shorter peripheral wall 21a is on the outer side by the directivity, and even when the shorter peripheral wall 21a is hooked at the corner part of the branching vessel 3, it slides through the corner part of the branching vessel 3 and is smoothly introduced to the branching vessel 3. <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, or a trachea.

  In recent years, for inspection and treatment of human tubular organs such as blood vessels, ureters, bile ducts, trachea, etc., a catheter is inserted to administer contrast agents, etc., or a portion of tissue is collected with forceps through the catheter. Has been done.

  That is, as shown in FIG. 10, first, a thin and flexible guide wire 1 is inserted into the tubular organ in advance, and after the distal end of the guide wire 1 reaches the target location, the guide wire 1 is moved along the outer periphery. Then, the catheter 2 is inserted. At this time, as shown in FIG. 10A, the distal end of the catheter 2 may be caught by the corner of the branch tube 3, and the catheter 2 cannot reach the target branch tube 3. (See FIG. 10B). This often occurs when the followability of the catheter 2 with respect to the guide wire 1 is poor.

In the following Patent Document 1, a main shaft having a suction lumen communicating from the proximal end to the most advanced portion inside, and a guide wire shaft having a guide wire lumen for following the guide wire inside the leading end portion of the main shaft. And a suction catheter having a hub at the proximal end of the main shaft, the distal end portion of the main shaft being cut in an oblique direction, and the distal end portion of the guide wire shaft being the diagonally cut end of the main shaft. An aspiration catheter is disclosed which is located at the distal end portion or protrudes further toward the distal end side than the most distal end portion.
JP 2004-65326 A

  The suction catheter of Patent Document 1 has a guide wire shaft on the distal end side of the main shaft. And in order to suppress the increase in the hardness of the main shaft by installation of this guide wire shaft, the front-end | tip of the main shaft is cut in the diagonal direction. Thereby, the flexibility of the suction catheter is ensured, and the followability of the catheter with respect to the guide wire is improved.

  However, when inserting a suction catheter into a bent branch in a blood vessel, there are the following problems. That is, since the guide wire shaft is provided at the distal end of the suction catheter, it is difficult to ensure sufficient flexibility even if the distal end is cut in an oblique direction, and it is bent at the branching portion of the blood vessel. It was difficult to insert smoothly. In addition, the guide wire shaft may be caught at the corner of the branch tube, and in this case, the suction catheter could not be smoothly inserted.

  Furthermore, the main shaft cut in the oblique direction is not disclosed in what direction the distal end of the main shaft is inserted in the branching portion of the blood vessel, and the significance of cutting the distal end of the main shaft in the oblique direction is not disclosed. Is considered only to ensure the flexibility of the main shaft.

  In addition, since the suction catheter is further provided with a guide wire shaft at the tip of the main shaft, the entire size of the suction catheter is increased, and it is difficult to insert into a thin blood vessel. Will also increase.

  Therefore, an object of the present invention is to improve the followability of the catheter to the guide wire at the branching portion of the blood vessel, to ensure that the catheter can reach the target branching tube, and to be easily inserted into a thin blood vessel. Another object of the present invention is to provide a catheter capable of reducing manufacturing costs.

  In order to achieve the above object, a first aspect of the present invention is a tube-shaped catheter having a shape in which the distal end portion of the catheter is cut obliquely, and a shorter peripheral wall of the distal end portion is formed on the other peripheral wall. The present invention provides a catheter characterized in that it is formed to be harder than the portion.

  According to the first invention, since the shorter peripheral wall at the distal end of the catheter cut obliquely is made harder than the other parts, the shorter peripheral wall is not easily deformed, while the opposite of the circumferential direction The longer peripheral wall on the side is easily deformed. That is, it becomes easy to bend with a directivity such that the longer peripheral wall of the tip is on the inner side and the shorter peripheral wall is on the outer side.

  Then, when the distal end of the catheter is led to a branching portion such as a blood vessel and is advanced along a guide wire previously inserted into the target branching tube, and the distal end of the catheter is inserted into the branching tube, The longer peripheral wall is bent inward, and the shorter peripheral wall is bent outward. As a result, even if the end of the peripheral wall in the short direction is caught by the corner of the branch pipe, the part is cut obliquely, so it slips through the corner of the branch pipe and smoothly introduces it into the target branch pipe can do.

  Therefore, according to the catheter of the present invention, the distal end of the catheter is not caught at the corner of the branch tube and can be smoothly advanced to the target branch tube. The followability of the catheter with respect to can be improved.

  Moreover, the catheter of this invention does not need to provide separately the member for inserting a guide wire in the outer periphery of a catheter like the said patent document 1. FIG. Therefore, since the catheter does not increase in size, it can be easily inserted even in a thin blood vessel, and it is not necessary to provide a member for inserting a guide wire, so that the manufacturing cost can be reduced.

  A second aspect of the present invention is a tube-shaped catheter having a shape in which the distal end portion of the catheter is cut obliquely, and a shape in which the longer peripheral wall of the distal end portion is bent inward. A catheter characterized by being shaped is provided.

  According to the second aspect of the invention, in addition to the distal end portion of the catheter being cut obliquely, the peripheral wall of the longer end portion is shaped in advance so as to be bent inward. When the distal end of the catheter is led to a branching portion such as a blood vessel and is advanced along a guide wire previously inserted into the target branching tube, and the distal end of the catheter is inserted into the branching tube, The longer peripheral wall is bent inward and the shorter peripheral wall is bent outward. As a result, even if the end of the peripheral wall in the short direction is caught in the corner of the branch pipe, that part is cut diagonally, so it slips through the corner of the branch pipe and smoothly introduces it into the target branch pipe can do. Therefore, also in the present invention, the followability of the catheter with respect to the guide wire can be improved particularly at the branching portion of the blood vessel. As in the first aspect of the invention, the catheter is not increased in size and can be easily inserted even in a thin blood vessel, and the number of constituent members is small, so that the manufacturing cost can be reduced.

  According to a third aspect of the present invention, in the first or second aspect of the invention, a cylindrical wall portion made of a member that is more flexible than the catheter extends to the end surface of the distal end portion that has an obliquely cut shape. The provided catheter is provided.

  According to the third aspect of the invention, when the cylindrical wall portion comes into contact with the corner portion of the branch tube of the blood vessel, the flexible cylindrical wall portion is pressed, so that the object is not caught by the corner portion of the branch tube. It can be smoothly advanced to the branch pipe.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the member for hardening the shorter peripheral wall of the tip end portion is bent toward the inner side of the longer peripheral wall of the tip end portion. As a member for shaping into a shaped shape or a member for reinforcing a catheter, a wire composed of a superelastic alloy disposed on the outer periphery and a radiopaque material disposed in the center thereof is used. A catheter is provided.

  According to the fourth aspect of the invention, the member for hardening the shorter peripheral wall of the distal end portion, the member for shaping the longer peripheral wall of the distal end portion into a bent shape, or a catheter The member that reinforces the material is composed of a superelastic alloy disposed on the outer periphery and a radiopaque material disposed in the center thereof, and therefore, compared with a member using only the radiopaque material. The position of the catheter can be visually recognized by a fluoroscopic camera when placed in a tubular organ such as a blood vessel, so that the catheter of the present invention can be accurately placed on a target treatment site. Can be detained.

  According to the catheter of the present invention, since the shorter peripheral wall at the distal end portion of the catheter cut obliquely is made harder than the other parts, the shorter peripheral wall is less likely to be deformed, whereas the opposite side in the circumferential direction The longer peripheral wall in the plate is easily deformed, and is bent with the directionality in which the shorter peripheral wall of the tip is on the outer side and the longer peripheral wall is on the inner side. Then, the distal end of the catheter is brought to a branching portion such as a blood vessel, and is advanced along a guide wire previously inserted into the target branching tube, and when the distal end of the catheter is inserted into the branching tube, The longer peripheral wall is bent inward and the shorter peripheral wall is bent outward. As a result, even if the end of the peripheral wall in the short direction is caught by the corner of the branch pipe, the part is cut obliquely, so it slips through the corner of the branch pipe and smoothly introduces it into the target branch pipe can do. In particular, it is possible to improve the followability of the catheter to the guide wire at the branching portion of the blood vessel. Further, unlike the above-mentioned Patent Document 1, it is not necessary to separately provide a member for inserting a guide wire, etc., so that the catheter can be prevented from being enlarged, can be easily inserted into a thin blood vessel, and the manufacturing cost can be reduced. I can plan.

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 hub 30 connected to the proximal end of the catheter main body 20. The 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. Further, the hub 30 has an introduction tube 31 communicating with the catheter main body 20, and a guide wire 40 described later is inserted through the introduction tube 31.

  The catheter body 20 has a proximal end portion 23 extending with a constant outer diameter. Further, a tapered portion 22 having a shape that is reduced in diameter from the proximal end portion 23 toward the distal end is formed, and the distal end portion 21 extends from the tapered portion 22. Thus, by making the distal end portion 21 smaller in diameter than the proximal end portion 23, the flexibility of the distal end portion 21 and the insertion property into the blood vessel are improved.

  Such a catheter body 20 is made of, for example, a synthetic resin such as polyurethane, nylon, polyethylene, polypropylene, or silicone. Further, a tube made of polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA) or the like is arranged on the inner side (hereinafter referred to as an inner tube), and a tube made of synthetic resin such as polyurethane described above is placed on the outer side. You may use what was coat | covered (henceforth an outer tube) and made | formed 2 layer structure. The inner tube is for ensuring lubricity with respect to the guide wire.

  Further, a catheter layer 20 may be formed by embedding a reinforcing layer between the inner tube and the outer tube. For example, the reinforcing layer is formed by alternately intersecting a metal wire made of a metal such as stainless steel, W, Au plated W, a metal such as a Ni-Ti alloy, or a wire made of a synthetic resin such as nylon or polyester. A so-called braided shape is preferably used. Or you may use the coil which consists of metal wires as a reinforcement layer. This reinforcing layer may be provided from the proximal end portion 23 of the catheter body 20 to the distal end portion, or may be provided slightly beyond the tapered portion 22 and before the distal end portion 21. Thus, by embedding the reinforcing layer, the torque transmission property, torsion resistance (kink resistance), and pushability of the catheter body 20 can be improved, and further, the catheter body 20 can be prevented from stretching. It becomes. The metal wire may be an X-ray opaque material, for example, a metal such as Pt, Pt alloy, W, Au-plated W, Au or the like. The position of can be grasped.

  Further, on the outer periphery of the catheter body 20, for example, polyvinyl pyrrolidone, polyethylene glycol, methyl vinyl ether maleic anhydride copolymer is used so as not to improve the lubricity of the catheter body 20 with respect to the inner wall of the blood vessel or to attach a thrombus as much as possible. It is preferable that a hydrophilic resin such as a coalescence is coated.

  Further, the distal end portion 21 of the catheter body 20 described above has a shape that is obliquely cut at the distal end with respect to the circumferential direction. As will be described later, the distal end portion 21 cut obliquely has a shorter peripheral wall 21a formed harder than other portions.

  Further, a marker ring 24 made of a radiopaque material is provided in the vicinity of the distal end portion 21 of the catheter body 20. Therefore, the position when the catheter 10 is inserted can be grasped by an X-ray monitor or the like. As the marker ring 24, for example, a metal such as Pt, Pt alloy, W, W plated with Au, or Au is preferably used.

  The catheter body 20 having such a shape is formed as follows, for example. First, the entire catheter body 20 is molded by extrusion molding or the like. Then, a core rod is inserted from the distal end of the catheter main body 20 and further pressed with a mold having a cavity having a diameter slightly smaller than the diameter of the catheter main body 20 while the distal end is heated and softened. Thereafter, the taper portion 22 is formed by dissolving the base end portion 23 and the tip end portion 21 with a solvent or the like to make it smooth. And the front-end | tip part 21 is cut diagonally, and the catheter main body 20 is formed.

  Alternatively, the base end portion 23 is molded separately by extrusion molding. And the front-end | tip part 21 and the taper part 22 are integrally molded by injection molding. And the front-end | tip of the base end part 23 and the base end of the taper part 22 are piled up, and in this state, the mandrel (not shown) made of metal is placed at a position where the base end part 23 and the taper part 22 overlap. Insert until And it inserts | pinches with the metal mold | die which consists of an up-and-down type | mold from the outer side of the overlapped position. In this state, the catheter main body 20 may be formed by applying a high-frequency voltage between the mold and the mandrel and performing dielectric heating to heat-weld the tapered portion 22 and the base end portion 23.

  2 to 5 show means for hardening the shorter peripheral wall 21a when the distal end portion 21 of the catheter body 20 is cut obliquely.

  FIG. 2 shows a first example of a means for making the shorter peripheral wall 21a of the distal end portion 21 harder than other portions. In the case of this example, the shorter peripheral wall 21a is formed thicker than the other portions. As a result, the shorter peripheral wall 21a is formed to be harder than other portions, particularly the longer peripheral wall 21b.

  FIG. 3 shows a second example of a means for making the shorter peripheral wall 21a of the distal end portion 21 harder than other portions. In the case of this example, a wire 25 is embedded in the shorter peripheral wall 21a and is formed to be harder than other portions.

  Examples of the material of the wire 25 include a Ni—Ti alloy, a Cu—Zn—X (X = Al, Fe, etc.) alloy, a Ni—Ti—X (X = Fe, Cu, V, Co, etc.) alloy, and the like. An elastic material, a metal wire such as stainless steel or piano wire, or a synthetic resin such as polyester or nylon is preferably used.

  The Ni-Ti alloy or the like is widely known as a shape memory alloy having a shape memory effect and a superelastic effect, and those having a superelastic effect have a yield point different from a normal metal material that undergoes plastic deformation. Even if a deformation strain exceeding this is applied, it returns to its original shape when unloaded, and has a high return characteristic against torsion and bending, and is therefore suitable as a means for adding hardness.

  FIG. 8 shows a wire 25a that is particularly preferably used in the present invention. The wire 25a is composed of a superelastic alloy b disposed on the outer periphery and a radiopaque material a disposed on the center thereof. The superelastic alloy b disposed on the outer periphery and the radiopaque material a disposed on the center may be integrated or may be moved separately. Since this wire 25a is formed of the radiopaque material a disposed in the center and the superelastic alloy b disposed on the outer periphery, the wire 25a can naturally bend and correspond to the bent portion of the tubular organ. And the visibility of the position of the wire 25a with a fluoroscopic camera, and the catheter of the present invention can be placed smoothly and accurately at a treatment site inside the tubular organ. be able to.

  As the X-ray opaque material a disposed in the central portion, a metal such as Au, Pt, or Pd is used. As the superelastic alloy b disposed on the outer periphery, a Ni—Ti-based shape memory alloy or the like is used. Preferably used. In addition, the relationship between the diameter X of the X-ray opaque material a disposed at the center in FIG. 8 and the diameter Y of the wire is such that the cross-sectional area of the X-ray opaque material a disposed at the center is the crossing of the wire. It is preferable to set it in a range of 10 to 40% with respect to the area.

  In addition, you may use the said wire 25a for the reinforcement layer which made the braid shape which consists of the above-mentioned metal wire, or the reinforcement layer which consists of a coil shape.

  FIG. 4 shows a third example of a means for making the shorter peripheral wall 21a of the distal end portion 21 harder than other portions. In this example, the surface of the shorter peripheral wall 21a is cured by irradiating it with UV light (ultraviolet light). In this case, the shorter peripheral wall 21a is formed of a resin material (including a monomer, an oligomer, a photopolymerization initiator, an additive, and the like) that is cured by irradiation with UV light. When the wall thickness of the shorter peripheral wall 21a is 0.03 to 0.2 mm as in this example, the shorter peripheral wall 21a is cured by irradiating with UV light for 5 to 60 seconds. When UV light is irradiated, the peripheral wall other than the shorter peripheral wall 21a is masked with a tape or the like and then irradiated with the UV light to prevent curing of other than the short peripheral wall 21a.

  FIG. 5 shows a fourth example of means for making the peripheral wall 21a of the shorter end portion 21 harder than other portions. In the case of this example, unlike the case of FIGS. 2-4, the slit 21c of predetermined length is formed in the longer surrounding wall 21b. Then, by reducing the strength of the longer peripheral wall 21b by the slit 21c, as a result, the shorter peripheral wall 21a becomes harder.

  Although not shown, the catheter body 20 is formed as described above, and then an acrylic adhesive such as cyanoacrylate is applied to the shorter peripheral wall 21a. It may be cured.

  Furthermore, although not shown, the shorter peripheral wall 21a may be made harder by using a resin material harder than the other parts. This is because a molding machine capable of supplying at least two types of resin materials is used, and resin materials having different hardnesses are supplied to the cavity of the mold by sequentially switching the nozzles for supply, etc. 21a is formed hard, and other portions are formed softly.

  The catheter 10 of the present invention formed as described above is used as shown in 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 into the blood vessel, and the catheter 10 is inserted along the outer periphery of the guide wire 40. Alternatively, when 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 operation of causing the catheter 10 to follow and advance may be repeated to advance the catheter 10.

  When the guide wire 40 reaches the branch portion of the blood vessel, the distal end portion of the guide wire 40 is advanced to the target branch tube 3. Next, the catheter 10 of the present invention is advanced along the outer periphery of the guide wire 40.

  At this time, in the catheter 10 of the present invention, the shorter peripheral wall 21a in the distal end portion 21 cut obliquely is formed harder than the other portions, so that the shorter peripheral wall 21a is not easily deformed. The longer peripheral wall 21b on the opposite side of the direction is easily deformed. That is, it becomes easy to bend with a directivity such that the shorter peripheral wall 21a at the tip end is on the outside and the longer peripheral wall 21b is on the inside.

  Therefore, as shown in FIG. 6, the catheter 10 of the present invention has the longer peripheral wall 21 b of the distal end portion 21 on the inner side and the shorter peripheral wall 21 a on the outer side, as shown in FIG. Even if the end portion of the peripheral wall 21a in the short direction is bent and caught on the corner portion of the branch pipe 3, the portion is cut obliquely, so that the desired branch can be smoothly slipped through the corner portion of the branch pipe 3 It can be introduced into the tube 3. As described above, according to the catheter 10 of the present invention, the distal end portion 21 of the catheter 10 is not caught at the corner of the branch tube 3 and can be smoothly advanced to the target branch tube 3. 6 can improve the followability of the catheter 10 with respect to the guide wire 40 at the branching portion of the blood vessel as shown in FIG.

  FIG. 7 shows another embodiment of the catheter of the present invention. Note that parts that are substantially the same as those of the above-described embodiment are given the same reference numerals, and descriptions thereof are omitted.

  The catheter shown in FIG. 7A is different from the above-described embodiment in that the shorter peripheral wall 21a in the distal end portion 21 cut obliquely is shaped in advance.

  In this case, for example, a shaping wire is embedded in either the short peripheral wall 21a or the long peripheral wall 21b of the catheter body 20, or the short peripheral wall 21a and the long peripheral wall 21b are embedded. Wires are embedded in both of them, and in this state, as shown in FIG. 7 (A), they are shaped so as to bend with the longer peripheral wall inside. As the wire at this time, the wire 25 for hardening the shorter peripheral wall 21a in FIG. 3 or the wire 25a shown in FIG. 8 is preferably used. Moreover, you may make it shape after embedding a coil instead of a wire.

  According to this embodiment, in addition to the distal end portion 21 of the catheter being cut obliquely, the longer peripheral wall 21b of the distal end portion 21 is previously shaped in a shape bent inward, so that the catheter 10 When the distal end 21 of the catheter 10 is advanced along the guide wire 40 previously inserted into the target branching tube 3 and the distal end 21 of the catheter 10 is inserted into the branching tube 3, Depending on the shape, the longer peripheral wall 21b of the tip 21 is bent inward and the shorter peripheral wall 21a is bent outward. As a result, even if the end portion of the peripheral wall 21a in the short direction is caught by the corner portion of the branch pipe 3, the target portion is smoothly slipped through the corner portion of the branch pipe 3 because the portion is cut obliquely. It can be introduced into the tube 3. In particular, the followability of the catheter 10 with respect to the guide wire 40 at the branching portion of the blood vessel can be improved.

  The catheter shown in FIG. 7B is different from the above-described embodiment in that a cylindrical wall portion 26 is further formed on the distal end portion 21 cut obliquely.

  The cylindrical wall portion 26 is formed of a material that is more flexible than the tube body 20. And according to this, when a cylindrical wall part contacts the corner | angular part of the branch pipe 3 of the blood vessel, since the flexible cylindrical wall part 26 is pressed, the object is not caught in the corner part of the branch pipe 3. It is possible to smoothly proceed to the branch pipe 3. The cylindrical wall portion 26 is molded by potting molding or dipping molding, in which a resin-dissolved liquid is poured, at the tip portion 21 that is cut obliquely.

  In addition, as FIG.7 (C) shows, the front-end | tip part 21 cut diagonally may partly be cut.

Example A catheter 10 having the shape shown in FIG. 1 was produced.

  First, the proximal end portion 23 of the catheter body 20 was formed by an extrusion molding machine. That is, a core material having an outer diameter of 0.55 mm and a predetermined length was used. Polyurethane was extruded into the core material, coated with the core material, and formed into a tube shape. The outer diameter of the base end 23 at this time was 0.85 mm.

  The tip portion 21 and the tapered portion 22 were molded by an injection molding machine. The inner diameter at this time was 0.55 mm, and the outer diameter was 0.80 mm.

  And the front-end | tip of the base end part 23 and the base end of the taper part 22 are piled up, and the metal mandrel which is not shown in figure in this state is inserted to the position where the base end part 23 and the taper part 22 overlapped. . Then, from outside the overlapped position, it was sandwiched between upper and lower molds (not shown), and a high frequency voltage was applied between the mold and the mandrel to perform dielectric heating. As a result, the taper part 22 and the base end part 23 were joined by heat welding.

  Furthermore, the front-end | tip part 21 was cut diagonally so that it might become an angle of 60 degree | times with respect to the longer surrounding wall 21b.

  Then, using a cyanoacrylate adhesive, it was applied to the shorter peripheral wall 21a of the tip 21 and cured.

  Furthermore, the marker ring 24 was attached to the distal end portion 21 to obtain the catheter 10 of the present invention.

  When the catheter 10 thus obtained is inserted along the outer periphery of the guide wire 40 at the branch portion of the blood vessel as shown in FIG. 6 and is allowed to proceed as it is, it is not caught by the corner of the branch tube 3. It was possible to smoothly advance to the target branch tube 3 and to confirm that the followability of the catheter to the guide wire was improved.

Test Example For various catheters, the followability to the guide wire was tested.

  A blood vessel model 100 having a plurality of branch paths 102, 103, 104 as shown in FIG. 9 was prepared. The branch paths 102, 103, and 104 are formed to be inclined with respect to the straight path 101 at angles of 120 degrees, 90 degrees, and 60 degrees, respectively. At this time, the width of the branch paths 102, 103, and 104 was 1 mm, and the width of the linear path 101 was 3 mm.

  The blood vessel model 100 is filled with distilled water, and in this state, the guide wire 105 is inserted from the start end (right side in FIG. 9) of the linear passage 101 and 20 mm from the branch point into each of the branch passages 102, 103, and 104. The guide wire 105 was set so that the tip of the guide wire 105 was positioned at a distance of. In this state, the catheters of the samples 1 to 3 shown below (shown by imaginary lines in FIG. 9) are inserted, followed by the guide wire 105, and each catheter advances to the branch paths 102, 103, and 104. It was confirmed whether or not

Sample 1
A catheter similar to the above-described example was produced. However, the tapered portion 22 is not formed, and the catheter body has a constant diameter. At this time, the inner diameter of the catheter body was 0.55 mm, and the outer diameter was 0.85 mm. And the front-end | tip part was cut diagonally so that it might become an angle of 60 degree | times with respect to the longer surrounding wall. Further, a cyanoacrylate adhesive was applied to the shorter peripheral wall of the tip portion within a range of 30 mm from the end portion to cure the shorter peripheral wall.

Sample 2
A catheter similar to Sample 1 was prepared except that the tip of Sample 1 was not cut and the angle was 90 degrees with respect to the longer peripheral wall.

Sample 3
A catheter was prepared without cutting the distal end of the catheter body, at an angle of 90 degrees with respect to the longer peripheral wall, and without applying any adhesive. Other configurations are the same as those of the sample 1.

  Using the catheters of Samples 1 to 3 described above, the followability of the catheter with respect to the guide wire was tested. The results are shown in Table 1.

  Among the results, the meanings of the symbols are as follows. (Double-circle) is a case where it was able to insert smoothly, without feeling caught, when inserting a catheter. ○ is a case where a slight catch was felt, but if the push-pull operation was performed such that the catheter was pulled back slightly and pushed further, it could be inserted. X is a case where it was not able to insert even if it pushed and pulled.

  As shown in Table 1, when the tip is cut obliquely and the shorter peripheral wall is hardened as in Sample 1, it can be inserted at any branching angle. It was revealed that the followability of the catheter was improved. Further, as in the case of the sample 2, the catheter is followed even in the case of the branch passage 104 inclined at an acute angle such as 60 degrees with respect to the linear passage 101 as compared with the case where the distal end portion is not cut obliquely. Thus, it was confirmed that the followability of the catheter with respect to the guide wire was improved.

  The present invention improves the followability of the catheter to the guide wire at the branch of the blood vessel, allows the catheter to reliably reach the target branch tube, can be easily inserted into a thin blood vessel, and further reduces the manufacturing cost. It can be used as a catheter that can be reduced.

It is a perspective view which shows one Embodiment of the catheter of this invention. The 1st example of the means to make the surrounding wall of the shorter one of the tip part of the catheter harder than other parts is shown, (A) is a sectional view at the time of cutting parallel to an axial direction, (B) These are sectional views in the AA arrow line. The 2nd example of the means to make the surrounding wall of the shorter one of the tip part of the catheter harder than other parts is shown, (A) is a sectional view at the time of cutting parallel to an axial direction, (B) These are sectional views in the direction of arrows BB. The 3rd example of the means to make the surrounding wall of the shorter one of the tip part of the catheter harder than other parts is shown, (A) is a sectional view at the time of cutting parallel to an axial direction, (B) These are sectional views in the CC arrow line. The 4th example of the means which makes the surrounding wall of the shorter one of the tip part of the catheter harder than other parts is shown, (A) is a sectional view at the time of cutting parallel to an axial direction, (B) These are sectional views in the direction of the arrow DD. It is explanatory drawing which shows the state which used the catheter in the branch part of the blood vessel. The other embodiment of the catheter of this invention is shown, (A) is explanatory drawing at the time of shaping the front-end | tip part of a catheter, (B) is the case where a cylindrical wall part is further provided in the front-end | tip part of a catheter It is explanatory drawing of. It is an example of the wire for making the short peripheral wall in the front-end | tip part of the catheter of this invention harder than another part. It is explanatory drawing which shows the method of the followable | trackability test of the catheter in an Example. The problem of the conventional catheter is shown, (A) is explanatory drawing when the front-end | tip of a catheter is caught in the corner | angular part of a branch pipe, (B) is the case where a catheter does not advance to the target branch pipe It is explanatory drawing.

Explanation of symbols

10 Catheter 21 Tip 21a Shorter peripheral wall 21b Longer peripheral wall 26 Cylindrical wall a Radiopaque material b Superelastic alloy

Claims (4)

  A tube-shaped catheter, characterized in that the distal end portion of the catheter is cut obliquely, and the shorter peripheral wall of the distal end portion is formed harder than other portions catheter.   A tube-shaped catheter, characterized in that the distal end portion of the catheter is obliquely cut and shaped so that the longer peripheral wall of the distal end portion is bent inward. And catheter.   The catheter according to claim 1 or 2, wherein a cylindrical wall portion made of a member more flexible than the catheter is provided on an end surface of the distal end portion having an obliquely cut shape.   Arranged on the outer periphery as a member for stiffening the shorter peripheral wall of the distal end, a member for shaping the longer peripheral wall of the distal end into a bent shape, or a member for reinforcing the catheter The catheter according to any one of claims 1 to 3, wherein a wire composed of the superelastic alloy formed and a radiopaque material disposed at the center thereof is used.

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