JP2016030035A - catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter of a new configuration which can effectively suppress projection of a braided wire constituting a blade while avoiding enlargement of a diameter at an end part in a lengthwise direction.SOLUTION: A catheter 10 comprises a blade tube 26 where a reinforcement blade 18 is fixed to a cylindrical wall 20. At least at one end part of the blade tube 26, end tubes 30a, 30b softer than the blade tube 26 are serially arranged with end surfaces in an axial direction abutted, a covering tube 32 thinner than the blade tube 26 is extrapolated across both tubes 26 and 30a, 30b at the abutment part between the blade tube 26 and the end tubes 30a, 30b, soldered on outer peripheral surfaces of both tubes 26, and 30a, 30b, and the end tubes 30a, 30b are extended outward from the end part in the axial direction of the covering tube 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a catheter used in the medical field, and more particularly to a catheter formed of a blade tube in which a tube made of a soft resin is reinforced with a wire material such as metal.

  Conventionally, various catheters have been used in the medical field. For example, a catheter may be inserted into a body such as a blood vessel to inject a drug solution or the like, or blood or body fluid may be collected, or treatment or examination may be performed with a device inserted into the body through such a catheter. Further, in medical equipment such as dialysis machines, catheters are also used for configuring blood and chemical fluid channels outside the body.

  As such a catheter, a tube made of a soft resin is generally used, and can be inserted into the body along a curved blood vessel or the like. Further, since it is preferable to have sufficient pushability when inserted into a blood vessel or the like, a blade of metal or the like is placed inside the cylinder wall as described in, for example, JP-A-6-134034 (Patent Document 1). Have been proposed and used as a catheter.

  By the way, as such a blade, a braided wire (braided sleeve) obtained by braiding a wire having a relatively high rigidity such as metal is generally used. Therefore, when a long blade tube is cut into an appropriate length to produce a product, the braided wire exposed at the end surface of the braid tube may protrude in the axial direction. Therefore, in a conventional blade tube, a resin tube without a blade is extrapolated and fixed to the end of the blade tube and extended in the axial direction, so that the axial end of the blade tube is configured with the resin tube. Has been proposed.

  However, even if the axial end of the blade tube is covered with such a resin tube, the braided wire may protrude from the end surface of the blade tube during bending or the like, and the braided wire may protrude through the resin tube to the outer peripheral surface. . In order to prevent such problems, the conventional structure of the tube tube has had to increase the thickness of the resin tube, and as a result, it is composed of a resin tube that is extrapolated to the blade tube. In addition, the outer diameter of the catheter tip portion is increased, and problems such as hindrance to handling and loss of flexibility may be pointed out.

JP-A-6-134034

  Here, the present invention was made in the background as described above, and the problem to be solved is a braided wire that constitutes a blade while avoiding an increase in diameter at the end in the length direction. It is an object of the present invention to provide a catheter having a novel structure capable of effectively suppressing the protrusion of the catheter.

  According to a first aspect of the present invention, there is provided a catheter comprising a blade tube in which a reinforcing blade is fixed to a cylindrical wall, and an end tube that is softer than the blade tube at an end of at least one of the blade tubes has an axial end surface. Are placed in series, and a covered tube thinner than the blade tube is extrapolated across the tubes at the butted portion of the blade tube and the end tube, and is placed on the outer peripheral surface of the tubes. The end tube is welded, and the end tube extends outward from the axial end of the cover tube.

  According to the catheter having the structure according to this aspect, the end tube is butted against the end surface of the blade tube, and the cover tube is extrapolated across the butted portion, so that the end tube and the cover tube work together. Thus, the protrusion of the blade from the blade tube is suppressed. Therefore, an increase in the wall thickness of the end tube, and an accompanying increase in diameter and a decrease in flexibility at the end of the blade tube can be suppressed.

  According to a second aspect of the present invention, in the catheter according to the first aspect, the covered tube is thinner than the end tube.

  According to the catheter having the structure according to this aspect, since the covered tube is thin, an increase in the outer diameter of the catheter is more effectively suppressed, and the flexibility of the catheter is easily secured. Particularly in the present invention, since the cover tube and the end tube work together to prevent the blade from protruding from the blade tube, in this aspect, the cover tube can be thinned while preventing the blade from protruding. .

  According to a third aspect of the present invention, in the catheter according to the first or second aspect, the covering tube is provided so as to cover the outer peripheral surface of the blade tube over substantially the entire length in the axial direction. is there.

  According to the catheter having the structure according to this aspect, since the covering tube is covered over substantially the entire length in the axial direction of the blade tube, the outer diameter dimension and the rigidity of the entire length direction of the catheter are reduced. Abrupt changes can be avoided. As a result, when an external force such as an operating force is applied to the catheter, the concentration of stress and strain is reduced or avoided, and bending and kinking of the catheter can be effectively prevented.

  According to a fourth aspect of the present invention, in the catheter according to any one of the first to third aspects, the divided tube divided into a plurality in the length direction is extrapolated to the blade tube and fused and integrated. Thus, the covering tube that covers the outer peripheral surface of the blade tube is configured.

  According to the catheter having the structure according to this aspect, the covered tube is configured by a divided tube divided into a plurality of portions in the length direction, so that even when the length of the blade tube is different, the divided tube to be extrapolated It is possible to easily cope with the problem by adjusting the number, and the workability of attaching the cover tube can be improved.

  According to a fifth aspect of the present invention, in the catheter according to the fourth aspect, at least one of the plurality of divided tubes has different characteristics with respect to the other divided tubes.

  According to the catheter having the structure according to this aspect, at least one of the plurality of divided tubes is set to a characteristic different from that of the other divided tubes, so that, for example, the length from the longitudinal end of the catheter is increased. An aspect in which the rigidity gradually increases as it goes inward in the vertical direction can be realized with a smaller difference in rigidity. Note that setting different characteristics means that the chemical, material, or mechanical characteristics such as material, strength, and rigidity are relatively different from each other in at least one divided tube.

  According to a sixth aspect of the present invention, in the catheter according to any one of the first to fifth aspects, an annular contrast marker is extrapolated to the blade tube, and the contrast marker is attached to the covered tube. It is covered with.

  According to the catheter having the structure according to this aspect, since the covering tube is provided on the outer peripheral side of the contrast marker, a sudden change in the outer diameter of the catheter at the attachment site of the contrast marker is suppressed, and the blood vessel of the catheter or the like The problem that the contrast marker projecting on the outer peripheral surface is hindered can be effectively avoided.

  According to the catheter having the structure according to the present invention, the end tube and the covering tube cooperate to effectively suppress the protrusion of the blade from the blade tube. Accordingly, it is not necessary to make the end tube excessively thick, and an increase in the outer diameter of the catheter end can be suppressed.

The front view which shows the whole catheter for embolus removal comprised including the delivery catheter which is one Embodiment of the catheter in this invention. The front view which shows the whole delivery catheter which is one Embodiment of the catheter in this invention. The front view which expands and shows the principal part of FIG. The enlarged view in the IV-IV cross section of FIG. Sectional drawing which shows the principal part in the VV cross section of FIG. The front view which shows the whole filter shaft which comprises the catheter for embolus removal shown by FIG. The front view which shows the whole collection | recovery catheter which is another embodiment of the catheter in this invention. The graph for demonstrating the outer diameter dimension of the delivery catheter as Example 1 of this invention compared with the comparative example 1. FIG. The delivery catheter as Example 1 of this invention WHEREIN: The graph for demonstrating the relationship between the distance X from a catheter front-end | tip to a spindle position, and the resistance value Y at the time of catheter pushing-in compared with the comparative example 1. FIG. The graph for demonstrating the relationship between the movement distance at the time of inserting the collection catheter as Example 2 of this invention in a blood vessel model, and resistance value compared with the comparative example 2. FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, FIG. 1 shows an embolus removal catheter 12 including a delivery catheter 10 which is an embodiment of the catheter of the present invention. Moreover, the single body of this delivery catheter 10 is shown by FIGS. The delivery catheter 10 is a catheter for delivering a filter for removing a thrombus or blood clot in blood to a treatment site. In the following description, the axial direction means the left-right direction in FIG. 1 where the delivery catheter 10 extends, the distal end side means the left side in FIG. 1, and the proximal end side means the right side in FIG. And

  More specifically, the delivery catheter 10 includes a distal-side distal shaft 14 and a proximal-side proxy shaft 16. The distal shaft 14 is composed of a single layer resin tube or the like, while the proxy shaft 16 is a hollow long member, and is composed of a metal such as stainless steel or a synthetic resin.

  The distal shaft 14 is fixed to the distal end portion of the proxy shaft 16, and the long proximal shaft 16 extends from the proximal end side of the distal shaft 14. The inner diameter dimension of the distal shaft 14 is larger than the outer diameter dimension of the proxy shaft 16, and a port portion in which the proximal end side of the distal shaft 14 opens to the outside in the middle portion of the delivery catheter 10 in the longitudinal direction. 22 Further, at the proximal end of the proximal shaft 16, a connector portion 24 that allows a user to hold and operate is provided.

  On the other hand, an outer tube 26 made of a blade tube is externally inserted at the distal end portion of the distal shaft 14. In this embodiment, the blade tube targeted by the present invention is the outer tube 26. As will be described in detail below, the catheter targeted by the present invention is connected to the outer tube 26 according to the present invention. The composite structure is provided with a tube and a covered tube. Therefore, the present invention can be interpreted without including the distal shaft 14 and the proximal shaft 16 as targets.

That is, the outer tube 26 is configured by the reinforcing blade 18 being embedded and fixed to the cylindrical wall 20 made of a resin tube, and the delivery catheter 10 is configured by the blade tube over substantially the entire length in the axial direction. Yes. In the present embodiment, the radial width dimension T _O (see FIG. 4) of the outer tube 26 is preferably 0.04 mm ≦ T _O ≦ 1.0 mm, and the axial dimension L _O (see FIG. 3). Is preferably 50 mm ≦ L _O ≦ 70 mm. By setting the radial thickness dimension T _O and the axial dimension L _O within the above ranges, flexibility and good operability can be obtained. Further, an annular contrast marker 28 made of Pt or the like is attached to the distal end portion of the outer tube 26 by being extrapolated.

  The outer tube 26, which is a blade tube, has a three-layer structure. The innermost layer is formed of a synthetic resin such as PTFE, and a wire made of a metal such as thin stainless steel or a synthetic resin on the outer peripheral side of the inner layer. A reinforcing blade 18 made of a mesh-like sleeve braided is disposed. Further, an outer layer of a synthetic resin made of polyamide or the like is formed on the outer peripheral side of the reinforcing blade 18, and the outer peripheral surface of the inner layer and the inner peripheral surface of the outer layer are bonded or welded, whereby the reinforcing blade The inner and outer layers are integrated by fixing in a state where 18 is embedded.

  In addition, end tubes 30a and 30b are arranged in series at both ends of the outer tube 26 with the outer tube 26 and the end face abutting each other. The end blades 30 a and 30 b are not embedded with the reinforcing blade 18, and the end tubes 30 a and 30 b are softer than the outer tube 26.

Further, the end tubes 30a and 30b have substantially the same inner diameter and outer diameter as the outer tube 26, and preferably have an axial dimension L _E (see FIG. 3) of 15 mm ≦ L _E ≦ 30 mm. ing. End tube 30a, by the axial dimension L _E of 30b is within the above range, flexibility at the ends is obtained with a predetermined length in the axial direction. Further, by making the inner and outer diameters of the end tubes 30a and 30b substantially equal to those of the outer tube 26, the reinforcing blade 18 disposed at the intermediate portion in the thickness direction of the outer tube 26 is projected to the inner and outer surfaces of the tube. It can be effectively suppressed in cooperation with the cover tube 32 described later.

  Further, a cover tube 32 is provided on the outer peripheral side of the outer tube 26 so as to cover the outer peripheral surface of the outer tube 26 over the entire length in the axial direction. The covered tube 32 is extrapolated across both butted portions of the outer tube 26 with the end tubes 30a and 30b, and the end tubes 30a and 30b extend outward from both axial ends of the covered tube 32. I'm out. The covered tube 32 is fixed to the outer peripheral surface of the outer tube 26 and the end tubes 30a and 30b by bonding, welding, or the like over the entire length of the covered tube 32. The covered tube 32 is disposed so as to cover the outer periphery of the contrast marker 28.

  In this embodiment, the covered tube 32 is divided into four in the length direction to form divided tubes 34a, 34b, 34c, and 34d, respectively. In other words, the divided tubes 34a, 34b, 34c, 34d arranged in series in the length direction are extrapolated to the outer tube 26 and the end tubes 30a, 30b. And these division | segmentation tubes 34a, 34b, 34c, 34d, the outer tube 26, and the end tubes 30a, 30b are heat-processed, these are fuse-integrated and the covered tube 32 is comprised, The covering tube 32 is welded to the outer peripheral surfaces of the outer tube 26 and the end tubes 30a and 30b. That is, the divided tubes 34 a and 34 d at both ends are welded to both the tubes over the outer tube 26 and the end tubes 30 a and 30 b, and the intermediate divided tubes 34 b and 34 c are welded to the outer tube 26.

In the present embodiment, the divided tubes 34a, 34b, 34c, and 34d have the same size, and the radial width dimension T _C (see FIG. 4) is preferably 0.01 mm ≦ T _C ≦ 0.05 mm. The axial dimension L _C (see FIG. 3) is preferably 5 mm ≦ L _C ≦ 40 mm. When the radial width dimension T _C and the axial dimension L _{C of the} divided tubes 34a, 34b, 34c, and 34d are within the above ranges, good workability is obtained and the end tubes 30a and 30b cooperate. The protrusion of the blade can be suppressed. Preferably, the covered tube 32 is thinner than the outer tube 26 and the end tubes 30a and 30b.

  In the outer tube 26 as described above, the distal end portion of the distal shaft 14 is inserted from the base end side of the end tube 30b provided on the base end side thereof, and the base end side inner periphery of the base end side end tube 30b is inserted. The delivery catheter 10 of the present embodiment is configured by reducing the diameter of the surface by welding or bonding to the outer peripheral surface of the distal shaft 14.

  The delivery catheter 10 having the shape as described above is attached with a wire 36 with a filter as shown in FIG. The wire with filter 36 has a longitudinal shape as a whole, and includes a long wire portion 38. In addition, a filter portion 40 is provided at the distal end portion of the wire portion 38, and the wire portion 38 is divided by the filter portion 40. In other words, the wire portion 38 extends from the distal end and the proximal end of the filter portion 40. On the other hand, the proximal end portion of the wire portion 38 is a proximal end portion 41 for a user to hold and operate.

  The wire portion 38 has an axial dimension longer than that of the delivery catheter 10, and is formed of, for example, a synthetic resin having a certain degree of flexibility or stainless steel. In this embodiment, the stainless steel extends continuously in the axial direction and has a certain degree of flexibility. The diameter dimension of the wire portion 38 is smaller than the inner diameter dimension of the distal shaft 14 so that the wire portion 38 can be inserted into the inner hole of the distal shaft 14.

  Further, in the wire portion 38, annular contrast rings 42 a and 42 b are extrapolated at both ends of the filter portion 40, and the proximal end side of the distal end side contrast ring 42 a is inserted into the inner hole of the distal shaft 14. Thus, the inside of the distal shaft 14 can be slid. The filter portion 40 has a cylindrical shape having a spiral structure as a whole, and is formed of a Ni—Ti alloy in the present embodiment. Furthermore, a synthetic resin formed from a nonwoven fabric or a woven or knitted fabric of a biocompatible material such as polyurethane is provided on the distal end side of the spiral portion of the filter portion 40 so that blood or the like can pass through the filter portion 40. On the other hand, thrombi and blood clots in blood cannot pass through the filter unit 40. The outer diameter of the contrast rings 42a and 42b is smaller than the inner diameter of the end tube 30a on the distal end side.

  Furthermore, a stopper 44 is fitted and fixed to the wire portion 38 on the distal end side of the contrast ring 42a on the distal end side. The stopper 44 has a tapered cylindrical shape with an outer diameter dimension that decreases toward the distal end side. The distal end side is substantially equal to the outer diameter dimension of the wire portion 38, while the proximal end side is closer to the distal end side. The outer diameter of the end tube 30a is made larger.

  The filter-equipped wire 36 having the above-described shape is inserted into the delivery catheter 10, whereby the embolus removal catheter 12 of the present embodiment is configured. Specifically, the proximal end of the wire with filter 36 is inserted from the distal end side opening of the end tube 30 a on the distal end side of the delivery catheter 10, and the proximal end of the wire with filter 36 is the base of the distal shaft 14. It protrudes from the port part 22 which is an end side opening part to the base end side. On the other hand, the filter part 40, contrast ring 42a, 42b, and stopper 44 provided in the front-end | tip part of the wire 36 with a filter are located in the front end side rather than the end tube 30a of the front end side.

  In using the embolus removal catheter 12 having the above-described structure, first, from the state of FIG. 1, for example, while fixing the delivery catheter 10, the proximal end portion 41 is grasped and the filter-attached wire 36 is secured to the proximal end. Pull to the side. As a result, the wire portion 38 inserted through the inner shaft of the distal shaft 14 and the outer tube 26 is pulled toward the proximal end, and the filter portion 40 and the contrast rings 42a and 42b protruding from the distal end of the delivery catheter 10 are removed from the outer tube. 26. At this time, since the filter portion 40 is formed of an Ni—Ti alloy having elasticity, the filter portion 40 is accommodated in the outer tube 26 while being elastically deformed. The pulling of the wire with filter 36 is limited by the base end of the stopper 44 coming into contact with the end tube 30a on the distal end side.

  Then, the embolus removal catheter 12 with the filter portion 40 accommodated in the outer tube 26 is inserted into a predetermined position through a guiding catheter previously placed in the blood vessel. Thereafter, in the catheter 12 for embolus removal that has reached the predetermined position, the delivery wire 10 is pulled out from the proximal end side while fixing the wire 36 with the filter, so that the wire 36 with the filter is indwelled at a predetermined position in the blood vessel. . At that time, the filter unit 40 is exposed from the outer tube 26, and is thus placed in the blood vessel in an expanded state as shown in FIG. 1 and FIG. 6 due to the elastic restoring action of the filter unit 40. . Thereby, the thrombus and blood clot in the blood vessel are efficiently captured by the filter unit 40.

  After such treatment, the filtered wire 36 placed in the blood vessel is recovered using the recovery catheter 48 shown in FIG. 7, which is another embodiment of the present invention. The recovery catheter 48 has substantially the same structure as the delivery catheter 10, but the recovery tube 50 of a substantially cylindrical shape with respect to the split tube 34 a at the distal end is more distal than the contrast marker 28 provided on the outer tube 26. The base end is extrapolated and fixed. As a result, the distal end side opening of the collection tube 50 is opened at the distal end of the collection catheter 48. In the recovery catheter 48, the distal shaft 14 and the proxy shaft 16 extend further to the distal end side in the outer tube 26 than the delivery catheter 10.

  Such a recovery catheter 48 is inserted into the guiding catheter, and the proximal end of the wire portion 38 is inserted from the distal end of the recovery catheter 48. Further, the recovery catheter 48 is pushed in so that the wire portion 38 protrudes from the port portion 22 of the recovery catheter 48 and the filter portion 40 is introduced into the recovery tube 50. In this manner, the filter-equipped wire 36 is recovered by pulling out the recovery catheter 48 from the guiding catheter in a state where the filter portion 40 is accommodated in the recovery tube 50 of the recovery catheter 48.

  In the delivery catheter 10 and the recovery catheter 48 of the present embodiment having the above-described structure, end tubes 30a and 30b are arranged in series with the end faces abutted against both ends of the outer tube 26 that is a blade tube. In addition, the covering tube 32 is extrapolated across the butted portion and welded to the outer peripheral surfaces of the outer tube 26 and the end tubes 30a, 30b. Due to the synergistic effect of the end tubes 30a and 30b and the covering tube 32, the blade protrusion in the blade tube is effectively suppressed as compared with the conventional structure in which the end tube is provided and welded.

  In particular, the effect of suppressing the protrusion of the blade is exerted with a synergistic effect of the end tubes 30a and 30b and the covered tube 32, so that it is not necessary to make the end tubes 30a and 30b excessively thick, and the distal end of the catheter The flexibility in this is also sufficiently secured. In addition, since the thickness dimension of the covered tube 32 is also kept small, an increase in the outer diameter dimension is suppressed even in a portion where the covered tube 32 is covered, and sufficient flexibility can be ensured.

  Further, in the delivery catheter 10, the soft end tube 30a is positioned at the most distal end, and the base end thereof is covered with the covering tube 32, and further, the outer end of the blade tube is covered with the outer tube 26. The tube 32 is covered and positioned. As a result, the catheter can be formed with a preferable mode in which the rigidity gradually increases from the distal end. That is, in this embodiment, since the end portion of the delivery catheter 10 is the soft end tube 30a and the covering tube 32 is provided at the abutting portion between the end tube 30a and the outer tube 26, the length of the catheter In the vertical direction, the rigidity gradually increases from the end tube 30a toward the outer tube 26. Therefore, a generally preferable aspect of the catheter can be realized in which the end portion of the delivery catheter 10 is flexible and the rigidity gradually increases as it goes inward in the axial direction.

  In addition, since the covered tube 32 covers the outer peripheral surface of the blade tube substantially over the entire length, the outer diameter and the rigidity of the covered tube 32 do not change abruptly. Therefore, bending of the catheter, kinking, etc. can be effectively prevented.

  In particular, since the covered tube 32 is divided into four divided tubes 34a, 34b, 34c, 34d in the length direction, good workability is exhibited when the outer tube 26 is covered.

  Furthermore, since the contrast marker 28 is attached by being extrapolated to the outer tube 26 and the cover tube 32 is provided so as to cover the contrast marker 28, the outer diameter of the catheter may change rapidly. It is suppressed and the insertion property of the catheter can be improved.

[Example 1]
As Example 1, the delivery catheter described in the above embodiment was prototyped, and the outer diameter and flexibility of the end portion and the tensile strength at break were measured. In the delivery catheter of Example 1, the outer tube was formed of PTFE on the inner layer, and a reinforcing blade formed of SUS304 was provided in a mesh shape on the outer peripheral side of the inner layer. Further, an outer layer was provided on the outer peripheral side of the blade layer by “PEBAX” (registered trademark) manufactured by Arkema Co., Ltd., and the inner layer and the outer layer were fixed to form a blade tube. The outer layer has a hardness of Shore D40. The distal shaft was formed as a single-layer tube made of polyamide, while the proxy shaft was formed of polyamide elastomer and stainless steel. The material and characteristics of the distal shaft and the proxy shaft are not limited. For example, a distal shaft formed of a polyamide elastomer can obtain the same measurement results as in this example.

Further, an annular contrast marker is fitted and fixed to the end portion of the outer tube, and end tubes are disposed on both ends of the outer tube so that the end surfaces are butted across both butted portions and the entire length of the outer tube. A covered tube was placed over the entire area. In addition, this covering tube was comprised by the divided tube divided into 4 equally in the length direction, and after covering the outer tube, these were fuse | melted and integrated. 60mm axial dimension L _O of such outer tube, 15 mm axial dimension L _E of the end tube, the axial dimension L _C of the divided tube was 20 mm. The inner diameter of the outer tube and the end tube was 0.9 mm and the outer diameter was 1.05 mm, while the inner diameter of the split tube was 1.1 mm and the outer diameter was 1.15 mm.

  On the other hand, a catheter having a conventional structure was adopted as the delivery catheter of Comparative Example 1. That is, instead of the structure in which the end tube and the cover tube were provided as in Example 1 described above, tubes without braiding were extrapolated and welded to both ends of the blade tube. Further, at the end of the outer tube, an annular contrast marker was fitted and fixed to the outer peripheral side of the unbraided tube.

  The results of measuring the outer diameter of the delivery catheters of Example 1 and Comparative Example 1 are shown in the graph of FIG. As can be seen from FIG. 8, the outer diameter of the outer tube of Example 1 is smaller than that of Comparative Example 1 at both ends. Moreover, since the change of an outer diameter dimension is small as a whole, it is guessed that the penetration property of a catheter is also improved.

  Further, in the delivery catheters of Example 1 and Comparative Example 1, the tensile strength at break was measured. In Example 1, the ends of the end tubes provided at both ends of the outer tube are each pulled outward in the axial direction, whereas in Comparative Example 1, the unbraided tube extrapolated at both ends of the blade tube The ends of each were pulled axially outward. And the load which the tube of these Examples 1 and Comparative Example 1 fractures was measured, respectively. The average value was calculated assuming that the number of trials was three.

  As a result, the load at which the tube of Comparative Example 1 was broken was 9.1 N, while the load at which the tube of Example 1 was broken was 11.4 N. Thereby, compared with the tube of the comparative example 1, the intensity | strength of the tube of Example 1 is large, and intensity | strength is covered by covering a covering tube over the full length of an outer tube like Example 1. FIG. It is assumed that it has grown.

  In addition, a two-point bending test was performed on the distal ends of the delivery catheters of Example 1 and Comparative Example 1 to measure the rigidity of the distal portion. As a loading point, the jig pushed the catheter from a point 1 mm from the distal end of the catheter, and the support shaft of the catheter was placed at a point X (mm) from the distal end of the catheter as a supporting point. And while changing the value of X, at the point of the said X (mm), resistance value Y (gf) when a jig pushes a catheter 1 mm is measured, X of Y in Example 1 and Comparative Example 1 Values were plotted on the graph. The result is shown in the graph of FIG.

  From this result, at the distal end of the catheter, the resistance value Y (gf) when the catheter is pushed in by 1 mm is smaller in Example 1 than in Comparative Example 1, and it can be pushed in a certain amount with a smaller force. It is possible. Thereby, it is shown that the catheter of Example 1 could improve the softness | flexibility in the front-end | tip part of the catheter compared with the catheter of a comparative example.

[Example 2]
As Example 2, the recovery catheter described in the above embodiment was prototyped and the passing performance of the bent portion was tested. As the recovery catheter of Example 2, a recovery tube chamfered in a curved shape is provided at the distal end of Example 1.

  Further, as Comparative Example 2, a recovery catheter provided with a recovery tube chamfered in a curved shape at the distal end portion of Comparative Example 1 was employed, and the passage performance of the bent portion was tested. In this test, a push-pull gauge is attached to each catheter, each catheter is inserted into a bending blood vessel model, and the movement distance of the catheter and the resistance value (N ) Was plotted on the graph. The result is shown in FIG.

  From this result, when each catheter is inserted into the blood vessel model, when the moving distance of the catheter is increased, the resistance value exerted on the hand of the catheter of Example 2 is smaller than that of the catheter of Comparative Example 2. Yes. Therefore, it is shown that the catheter of Example 2 can be inserted through the bent portion well because the change in the outer diameter is small and the tip is flexible compared to the catheter of Comparative Example 2. ing.

  As mentioned above, although embodiment and the Example of this invention were explained in full detail, this invention is not limited at all by the above-mentioned specific description.

  For example, as the catheter of the present invention, the delivery catheter 10 of the embolus removal filter and the recovery catheter 48 are exemplified in the above-described embodiment, but the present invention is not limited thereto, and the catheter of the present invention includes a suction catheter, Various catheters such as a balloon catheter, a delivery catheter for delivering a stent, a guiding catheter, an atherectomy angioplasty catheter, and a catheter having a plurality of lumens may be employed.

  Moreover, in the said embodiment, although the covering tube 32 was comprised by the same division | segmentation tube 34a, 34b, 34c, 34d, at least one of the division | segmentation tubes has a characteristic relatively different from another division | segmentation tube. It may be set. Here, the characteristics indicate chemical, material, or mechanical characteristics such as material, strength, and rigidity. Therefore, for example, if a split tube is adopted in which the rigidity of the split tube at both ends is small and the rigidity gradually increases inward in the axial direction, a catheter according to the rigidity of the split tube can be efficiently manufactured. Can be done. Further, for example, if a split tube whose rigidity is gradually increased as it goes in the proximal direction with the distal split tube having a small rigidity, a catheter according to the rigidity of the split tube can be efficiently manufactured. .

  Further, in the embodiment, the covering tube 32 is provided on the outer peripheral side of the contrast marker 28, but the contrast marker may be externally fixed on the outer peripheral side of the covering tube.

  Further, the reinforcing blade employed in the blade tube is not limited to a mesh shape, and may be, for example, a spiral shape that extends continuously in the axial direction. The material of the reinforcing blade is not limited to metal, and may be formed of, for example, a synthetic resin.

  Furthermore, in the above-described embodiment, both the delivery catheter 10 and the recovery catheter 48 for delivering and recovering the filter-attached wire 36 are the catheters according to the structure of the present invention, but either of the delivery catheter and the recovery catheter is used. Only one of them may be a catheter according to the structure of the present invention, and delivery and collection of the filtered wire 36 may be performed by these catheters.

10: Delivery catheter (catheter), 14: Distal shaft, 16: Proxy shaft, 18: Reinforcing blade, 20: Tube wall, 26: Outer tube (blade tube), 28: Contrast marker, 30a, 30b: End Tube, 34a, 34b, 34c, 34d: Dividing tube, 48: Collection catheter (catheter)

Claims (6)

A catheter comprising a blade tube having a reinforcing blade fixed to a cylindrical wall;
An end tube that is softer than the blade tube is disposed in series at at least one end of the blade tube so that the axial end surfaces thereof are in contact with each other, and a cover tube that is thinner than the blade tube includes the blade tube and the end tube. The end tube is extrapolated across both tubes and welded to the outer peripheral surface of both tubes, and the end tube extends outward from the axial end of the covered tube. Feature catheter.   The catheter according to claim 1, wherein the covering tube is thinner than the end tube.   The catheter according to claim 1 or 2, wherein the covering tube is provided so as to cover an outer peripheral surface of the blade tube over substantially the entire length in the axial direction.   4. The covered tube that covers the outer peripheral surface of the blade tube by forming the divided tube divided into a plurality in the length direction by being extrapolated to the blade tube and being fused and integrated. The catheter according to claim 1.   The catheter according to claim 4, wherein different characteristics are set in at least one of the plurality of divided tubes with respect to other divided tubes.   The catheter according to any one of claims 1 to 5, wherein an annular contrast marker is attached by being extrapolated to the blade tube, and the contrast marker is covered with the covering tube.