JP2021040947A - Support catheter and tube - Google Patents

Abstract

To provide a support catheter of a novel structure where one end part of a proximal shaft is unlikely to come off of a braid of a distal shaft, and a tube where a member to be fixed is unlikely to come off of the braid.SOLUTION: A support catheter includes: a distal shaft which is formed into a tube shape in which a treatment catheter is insertable and comprises an inner layer, a reinforcement layer around which a plurality of metal wires are wound in one direction and in the other and is formed into a cylindrical mesh-like shape, and an outer layer; and a proximal shaft connected to the distal shaft. The reinforcement layer includes a small pitch part where the wound metal wire pitch is first value and a large pitch part where pitch of the metal wire is second value larger than the first value. One end part of the proximal shaft is fixed to the large pitch part.SELECTED DRAWING: Figure 3

Description

The present invention relates to support catheters and tubes that are used in conjunction with therapeutic catheters and guiding catheters to guide therapeutic catheters to a therapeutic site.

For percutaneous coronary intervention (PCI), support catheters may be used along with therapeutic and guiding catheters.

The support catheter is formed in a tubular shape into which a therapeutic catheter can be inserted, and has a distal shaft including an inner layer, a reinforcing layer, and an outer layer, and a proximal shaft connected to the distal shaft. The reinforcing layer may include a tubular braid (see, for example, Patent Document 1) formed by winding a metal wire, a resin wire, or the like at a constant pitch.

Japanese Unexamined Patent Publication No. 2007-8802

By the way, as a method of connecting the proximal shaft and the distal shaft, a method of connecting the two by fixing one end of the proximal shaft on the reinforcing layer (braid) of the distal shaft can be considered.

However, when one end of the proximal shaft is fixed on a braid as in Patent Document 1 formed by winding a plurality of strands at a constant pitch, a tensile force in the longitudinal direction is applied to the distal shaft. In that case, a load is applied to the fixed portion between one end of the proximal shaft and the braid (wire), one end of the proximal shaft is peeled off from the wire, and the tip side of the proximal shaft forms an outer layer. There was a risk of breaking through and exposing.

Therefore, an object of the present invention is to provide a support catheter having a novel structure in which one end of the proximal shaft is hard to be peeled off from the braid of the distal shaft.

Further, it is also one of the problems to be solved in the present invention to provide a tube in which the member to be fixed is hard to be peeled off from the braid.

The support catheter according to the first aspect is used together with a therapeutic catheter for treating a treatment site and a guiding catheter into which the therapeutic catheter is inserted and for guiding the therapeutic catheter in a blood vessel. A support catheter that is inserted through the proximal opening of a guiding catheter, has a length that protrudes from the distal opening of the guiding catheter, and guides the distal portion of the therapeutic catheter to the treatment site. In addition to being formed in a tubular shape into which the therapeutic catheter can be inserted, an inner layer and a reinforcing layer formed by winding a plurality of metal wires in one direction and the other direction to form a tubular mesh shape are included. The reinforcing layer includes a distal shaft composed of, and a proximal shaft connected to the distal shaft, and the reinforcing layer includes a small pitch portion in which the pitch of the wound metal wire is the first value, and a wound. A large pitch portion having a second value in which the pitch of the metal wire is larger than the first value is included, and one end of the proximity shaft is fixed to the large pitch portion.

According to this aspect, a large pitch portion is provided in the reinforcing layer, and one end of the proximal shaft is fixed to the large pitch portion. As a result, when a tensile force in the longitudinal direction is applied to the distal shaft, the load applied to the fixed portion can be made smaller than when one end of the proximal shaft is fixed to the small pitch portion.

By fixing one end of the proximal shaft onto the braid of the distal shaft, the angle of the metal wire of the braid at the fixed portion is fixed. When a conventional distal shaft having a braid formed by winding at a constant pitch as a reinforcing layer is pulled in the longitudinal direction, the pitch becomes large in a portion not fixed by the proximal shaft (metal wire). While the braid gradually changes in the direction (the angle of the metal wire increases), the braid cannot follow the change in the portion where the angle of the metal wire is fixed. Therefore, a load is applied to the fixed portion which is the boundary between the variable portion where the pitch changes and the non-variable portion where the pitch does not change. On the other hand, since the distal shaft constituting the support catheter according to this embodiment is fixed in a state where the braided pitch (angle of the metal wire) is increased in advance, it is a proximal shaft even when it is pulled in the longitudinal direction. The load on the fixed portion caused by the change in the braid of the unfixed portion (change in the braid pitch and the angle of the metal wire) is suppressed. This makes it difficult for one end of the proximal shaft to come off the metal wire.

The second aspect is the support catheter according to the first aspect, wherein the reinforcing layer includes the two small pitch portions and the large pitch portion located between the two small pitch portions.

According to this aspect, the range in which the large pitch portion harder than the small pitch portion is provided is limited to the range in which one end of the proxy shaft is fixed, and the proximal end side from the range can be the small pitch portion. As a result, the flexibility of the distal shaft can be ensured and breakage can be prevented.

The third aspect is the support catheter according to the first aspect, which includes a gradual change pitch portion between the small pitch portion and the large pitch portion, and the gradual change pitch portion is from the large pitch portion. The pitch of the wound metal wire becomes smaller toward the small pitch portion.

According to this aspect, since the braided pitch gradually changes between the large pitch portion and the small pitch portion, it is possible to avoid a sudden change in hardness of the distal shaft and prevent breakage. From the viewpoint of ensuring flexibility, the gradual change pitch portion should be short, and from the viewpoint of gradual hardness change, the gradual change pitch portion should be long.

A fourth aspect is the support catheter according to the first aspect, in which one end of the proximity shaft is wound in the other direction with the metal wire wound in one direction at the large pitch portion. It is fixed at at least two or more intersections among a plurality of intersections where the rotated metal wire intersects and is lined up in the axial direction.

According to this aspect, since one end of the proximal shaft is fixed at at least two or more points of the large pitch portion, one end of the proximal shaft is peeled off from the fixed position located on the tip side where the load is most applied. Even so, the proximal shaft and the distal shaft will not be separated immediately.

The fifth aspect is the support catheter according to the first aspect, in which the acute angle formed by the wound metal wire and the straight line perpendicular to the longitudinal direction of the inner layer in the large pitch portion in a normal state is 25 °. It is 70 ° or more and 70 ° or less.

According to this aspect, the closer the acute angle is to 90 °, the higher the tensile strength of the distal shaft in the longitudinal direction, and the closer the acute angle is to 0 °, the more flexible the distal shaft is to move in the radial direction. It will be easier to take.

The tube according to the sixth aspect is a tubular inner layer and a reinforcing layer provided on the outer surface of the inner layer, in which a plurality of metal wires are wound in one direction and the other direction to form a tubular mesh shape. The reinforcing layer has a small pitch portion in which the pitch of the wound metal wire is the first value, and a second value in which the pitch of the wound metal wire is larger than the first value. It includes a large pitch portion, and is further provided with a fixed member fixed to the large pitch portion.

According to this aspect, a large pitch portion is provided in the reinforcing layer, and the member to be fixed is fixed to the large pitch portion. As a result, when a tensile force in the longitudinal direction is applied to the tube, the load applied to the fixed portion can be made smaller than when one end of the member to be fixed is fixed to the small pitch portion. As a result, the load on the fixed portion is suppressed as described above, and the fixed member is less likely to be peeled off from the metal wire (braid).

According to the present invention, it is possible to provide a support catheter having a novel structure in which one end of a proximal shaft is hard to be peeled off from the braid of the distal shaft, and a tube in which the fixed member is hard to be peeled off from the braid.

It is a figure which shows the state which the support catheter which concerns on one Embodiment of this invention is used together with a therapeutic catheter and a guiding catheter. It is a side view which shows the support catheter of FIG. It is a photograph of a distal shaft without an outer layer. It is the figure of the distal shaft in the state where the outer layer is not provided. It is a graph which shows the relationship between the braided pitch and the metal wire angle in a large pitch part. It is a figure which shows the fixing point in the reinforcing layer of one end part of a proximal shaft. (A) is a diagram showing a reinforcing layer of a conventional support catheter, and (b) is a diagram showing a state of the reinforcing layer when the proximal shaft of (a) is pulled. (A) is a diagram showing a reinforcing layer of the support catheter of the present embodiment, and (b) is a diagram showing a state of the reinforcing layer when the proximal shaft of (a) is pulled. It is a side view which shows the tube which concerns on one Embodiment of this invention.

Hereinafter, the support catheter according to the embodiment of the present invention will be described with reference to the drawings. The support catheter described below is only one embodiment of the present invention. Therefore, the present invention is not limited to the following embodiments, and additions, deletions, and changes can be made without departing from the spirit of the present invention. Further, the concept of the direction used in the following description is used for convenience in the explanation, and does not limit the direction of the configuration of the invention to that direction.

For example, percutaneous coronary artery intervention (PCI) is known as a technique for dilating a stenotic portion 3 formed in a coronary artery 2 as shown in FIG. In PCI, a guiding catheter 4, a balloon catheter 5, a support catheter 1 of the present embodiment, and a guide wire 25 are mainly used. Hereinafter, each member used in PCI will be described.

<Guiding catheter>
The guiding catheter 4 is a catheter for guiding the balloon catheter 5 and the support catheter 1 in the blood vessel, and is inserted into, for example, the radial artery 8 or the femoral artery (not shown) using the sheath 7. The guiding catheter 4 has a guiding catheter body 11 and a Y-shaped connector 12. The guiding catheter body 11 has a long tube shape, and is configured so that the balloon catheter 5 and the support catheter 1 can be inserted into the guiding catheter body 11. Further, the guiding catheter main body 11 is made of a bendable cylindrical flexible tube so as to be able to push forward in the curved blood vessel.

The Y-type connector 12 is provided at the proximal end portion of the guiding catheter main body 11. The Y-type connector 12 has a main body portion 12a and a side arm 12b so that a chemical solution or a contrast medium can be injected from the side arm 12b. Further, the tip portion of the main body portion 12a is attached to the proximal end portion of the guiding catheter main body 11. The main body portion 12a has a proximal end side opening 12c, from which the balloon catheter 5 and the support catheter 1 can be inserted.

<Balloon catheter>
The balloon catheter 5 is a therapeutic catheter, and a known one can be adopted. The balloon catheter 5 is a catheter that is inserted into the stenosis portion 3 in the coronary artery to expand the stenosis portion 3. The balloon catheter 5 is, for example, a rapid exchange type (RX type) catheter, and has a therapeutic catheter body 21 and a connector 22 as shown in FIG. The therapeutic catheter body 21 is formed in the shape of a long tube. The therapeutic catheter body 21 has a balloon 23 having a stent 24 externally attached to the tip portion thereof. The balloon catheter 5 is used together with the guide wire 25, the guiding catheter 4 and the support catheter 1.

<How to use the support catheter>
In the following, a method of approaching from the radial artery in PCI will be described with reference to FIG. The detailed configuration of the support catheter will be described later.

In this method, a support catheter 1, a guiding catheter 4, a balloon catheter 5, and a guide wire 25 are used. In PCI, the practitioner first punctures the radial artery 8 with a needle (not shown) and inserts a sheath 7 at the puncture site. After that, when the guiding catheter 4 is inserted into the radial artery 8 through the sheath 7, the guiding catheter 4 is pushed through the aortic arch 9 until the distal opening 4a reaches the entrance 2a of the coronary artery 2, and the guiding catheter 4 is pushed forward until it reaches the entrance 2a of the coronary artery 2. When the opening 4a reaches the inlet 2a, the guide wire 25 is inserted, and the support catheter 1 is inserted through the proximal opening 4b of the guiding catheter 4. While being pushed and pulled by the practitioner, the support catheter 1 is pushed forward in the guiding catheter 4 while being guided by the guide wire 25 until the distal end side portion protrudes from the distal end side opening 4a. As a result, the distal end side portion of the support catheter 1 is inserted into the coronary artery 2 and further reaches the stenosis portion 3.

After pushing the distal end side portion of the support catheter 1 to the stenosis portion 3 in this way, the balloon catheter 5 is inserted from the proximal end side opening 4b of the guiding catheter 4. The tip of the balloon catheter 5 is inserted into the distal shaft 33 and then pushed forward until it protrudes from the tip of the distal shaft 33. By pushing forward in this way, the tip portion of the balloon catheter 5 is inserted into the stenosis portion 3, and the balloon 23 and the stent 24 are located at the stenosis portion 3. Then, the pushing of the balloon catheter 5 is stopped.

By pushing the balloon catheter 5 in this way, the tip portion of the balloon catheter 5 is guided to the entrance 2a of the coronary artery 2 by the guiding catheter 4, and further guided to the stenosis portion 3 by the support catheter 1 at the tip of the entrance 2a. Further, since the distal shaft 33 of the support catheter 1 extends to or near the stenosis portion 3, when the tip portion of the balloon catheter 5 is pushed into the stenosis portion 3, the tip portion of the balloon catheter 5 is caused by the tip portion of the distal shaft 33. Is supported. After that, the balloon 23 is inflated by the pressure fluid. At the same time, the stent 24 is expanded and expanded, and the stenosis portion 3 is expanded. By such a method, the blood flow of the narrowed portion 3 can be restored.

<Support catheter>
Next, the configuration of the support catheter in this embodiment will be described. As described above, the support catheter 1 is a catheter that is advanced to a position close to the stenosis portion 3 and guides the balloon 23 of the balloon catheter 5 to the stenosis portion 3. The support catheter 1 is also a catheter for supporting the balloon 23 when the balloon 23 is inserted into the narrowed portion 3. Such a support catheter 1 has a length that is inserted from the proximal end side opening 4b of the guiding catheter 4 and protrudes from the distal end side opening 4a of the guiding catheter 4.

As shown in FIG. 2, the support catheter 1 includes a protective member 32, a distal shaft 33, and a proximal shaft 34 connected to the distal shaft 33.

The proximal shaft 34 is a long wire rod made of, for example, a metal such as stainless steel or a synthetic resin such as polyimide or polyetheretherketone. The surface of the proximal shaft 34 is coated with, for example, PTFE. The protective member 32 is provided at the base end portion of the proximal shaft 34. The protective member 32 is a columnar member made of a polyamide elastomer or the like.

The distal shaft 33 is formed in a substantially cylindrical shape, and is configured so that the balloon catheter 5 can be inserted. As shown in FIG. 3, the distal shaft 33 is a member having a three-layer structure including an inner layer 35, a reinforcing layer 36, and an outer layer 37 (FIG. 2) in this order from the inside.

The inner layer 35 of the distal shaft 33 is formed of, for example, polytetrafluoroethylene (PTFE) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA). As a method for manufacturing the inner layer 35, for example, PTFE is applied to the outer surface of a silver-plated copper wire to form the inner layer 35. The material of the inner layer 35 is not limited to the above.

The reinforcing layer 36 of the distal shaft 33 is formed by winding, for example, a plurality of metal wires (wires) 36a made of stainless steel in one direction and the other direction to form a tubular mesh shape (cylindrical mesh shape). It is provided on the outer peripheral surface of the inner layer 35.

The outer layer 37 of the distal shaft 33 is formed in a substantially cylindrical shape, and is formed of, for example, a nylon-based elastomer resin or polybutylene terephthalate. It is preferable that the base end side portion of the outer layer 37 is cut diagonally as shown in FIG. 2 or formed in an arc shape or a crescent shape. In this case, it is preferable that the base end side portion of the inner layer 35 is also formed in the same shape. This makes it easier to insert the balloon catheter 5 into the distal shaft 33. Although the number of outer layers is one, the number is not limited to this, and two or more outer layers may be adopted. The material of the outer layer 37 is not limited to the above.

The inner layer 35 and the outer layer 37 may be configured by using the same material as each other, and are not limited to the above-mentioned materials. Further, the outer peripheral surface of the outer layer 37 may be coated with a hydrophilic polymer containing polyurethane, polyvinylpyrrolidone (PVP) or the like.

A tip 38 is provided at the tip of the distal shaft 33. The tip 38 is made of a polyamide elastomer containing, for example, bismuth oxide, which is a contrast medium, and is formed in a substantially cylindrical shape. The tip 38 has radiopaqueness, and shadows appear under fluoroscopy.

Here, the reinforcing layer 36 provided on the outer peripheral surface of the inner layer 35 of the distal shaft 33 will be described in detail.

When forming the reinforcing layer 36, for example, 16 metal wires 36a are used. Eight of the 16 metal wires 36a are spirally wound in one direction on the outer peripheral surface of the inner layer 35, and the remaining eight are spirally wound in the other direction on the outer peripheral surface of the inner layer 35 to form a reinforcing layer. 36 can be formed. The number of metal wires 36a to be wound is not limited to eight in each direction. Further, the method of winding the metal wire 36a is not limited to a spiral shape, and a conventionally known method can be adopted.

As shown in FIGS. 3 and 4, the reinforcing layer 36 includes a large pitch portion 50, two gradually changing pitch portions 51, and two small pitch portions 52. For example, the length of the large pitch portion 50 is 1 to 30 mm, the length of the small pitch portion 52 on the tip side is 200 to 500 mm, the length of the small pitch portion 52 on the base end side is 0 to 30 mm, and each gradual step. The length of the variable pitch portion 51 can be 1 to 5 mm. However, the length of each part is appropriately set depending on the blood vessel site to which the support catheter 1 is applied, and is not limited to this. From the viewpoint of ensuring flexibility, the gradual change pitch portion 51 should be short, and from the viewpoint of gradual hardness change, the gradual change pitch portion 51 should be long.

The large pitch portion 50 is arranged between the two small pitch portions 52. Further, one slowly changing pitch portion 51 is arranged between one small pitch portion 52 and the large pitch portion 50, and the other slowly changing pitch portion 51 is located between the other small pitch portion 52 and the large pitch portion 50. Is located in.

The small pitch portion 52 is a portion where the braided pitch (pitch) is the first value. The braid pitch is the phase (for example, 0 ° position) in the circumferential direction on the reinforcing layer 36 of one metal wire 36a wound in one direction (or the other direction), but may be at any angle position. ) Are the same as each other and are the distances between one part and the other part that are adjacent to each other in the axial direction. That is, the distance from one portion at the 0 ° position to the other portion located at the same 0 ° position when the metal wire 36a is wound. The first value may be a value smaller than the second value that can be taken by the large pitch portion 50, which will be described later, and is appropriately set depending on the blood vessel site to which the support catheter 1 is applied and is not limited. ..

On the other hand, the large pitch portion 50 is a portion where the braided pitch is a second value larger than the first value. As shown in FIG. 7A, which will be described later, the acute angle (metal wire angle) α formed by one metal wire 36a in the large pitch portion 50 and the straight line L perpendicular to the length direction of the proximity shaft 34 in the normal state is In a plan view, for example, it is 25 ° or more and 70 ° or less, and when the angle α is in the range, the range in which the second value can be taken is, for example, 2 to 10 mm as shown in FIG. The support catheter 1 in the normal state is assumed to be in a state of being housed in the package or in an unused and unloaded state after being taken out of the package.

Further, the gradually changing pitch portion 51 is a portion where the braided pitch becomes smaller from the large pitch portion 50 toward the small pitch portion 52. For example, when the braided pitch of the large pitch portion 50 is 6 mm and the braided pitch of the small pitch portion 52 is 2 mm, the braided pitch of the gradually changing pitch portion 51 gradually changes in the range of 6 mm to 2 mm.

In the present embodiment, one end of the proximity shaft 34 is welded to the large pitch portion 50 and the small pitch portion 52 on the proximal end side. Specifically, one end of the proximal shaft 34 is a plurality of metal wires 36a wound in one direction and a metal wire 36a wound in the other direction intersecting and arranged in the axial direction in the large pitch portion 50. It is fixed at at least two or more of the intersections. The fixing method is, for example, welding, but is not limited thereto. In this case, as shown in FIG. 6, one end of the proximal shaft 34 is welded at every other intersection of the plurality of intersections in the large pitch portion 50. Reference numeral P in FIG. 6 indicates a welding point. Further, one end of the proximal shaft 34 is welded at every two or more intersections among the plurality of intersections in the small pitch portion 52. As shown in FIG. 8A described later, one end of the proximal shaft 34 may be welded at each of the plurality of intersections at the large pitch portion 50 and the small pitch portion 52.

Next, the operation of the support catheter 1 of the present embodiment and the effect thereof will be described with reference to FIGS. 7 and 8. It should be noted that FIGS. 7 and 8 are schematic views that give priority to an easy understanding of the action and effect, although they lack accuracy. When the conventional distal shaft 133 having a braid having a constant braid pitch shown in FIG. 7 (a) as a reinforcing layer (conventional reinforcing layer) 136 is pulled in the direction of the arrow shown in FIG. 7 (b), In the portion not fixed by the proximal shaft 34, the braid 136 gradually changes in the direction in which the braid pitch increases (the angle of the metal wire 36a increases), while in the portion where the angle of the metal wire 36a is fixed. Braid 136 cannot follow the change. Therefore, a load is applied to the fixed portion P1 which is the boundary between the variable portion where the braid pitch changes and the non-variable portion where the pitch does not change. Therefore, one end of the proximal shaft 34 is easily peeled off from the metal wire 36a.

On the other hand, since the large pitch portion 50 of the distal shaft 33 constituting the support catheter 1 of the present embodiment has a large braided pitch in advance, the distal shaft 33 of the present embodiment shown in FIG. 8A is shown in FIG. Even when pulled in the direction of the arrow shown in 8 (b), to the fixed portion P2 caused by a change in the braid 36 of the portion not fixed by the proximal shaft 34 (change in the braid pitch or the angle of the metal wire 36a). The load is suppressed. As a result, one end of the proximal shaft 34 is less likely to be peeled off from the metal wire 36a. In FIG. 8, the gradually changing pitch portion 51 is not shown.

As described above, according to the support catheter 1 of the present embodiment, the reinforcing layer 36 is provided with the large pitch portion 50, and one end of the proximal shaft 34 is fixed to the large pitch portion 50. As a result, when a tensile force in the longitudinal direction is applied to the distal shaft 34, the load applied to the fixed portion of the large pitch portion 50 at one end of the proximal shaft 34 is applied to the fixed portion of the proximal shaft 34 at one end of the proximal shaft 34. It can be made smaller than when it is fixed to 52. As a result, one end of the proximal shaft 34 is less likely to be peeled off from the metal wire 36a.

Further, in the present embodiment, the braided pitch gradually changes between the large pitch portion 50 and the small pitch portion 52 by providing the gradually changing pitch portion 51 between the large pitch portion 50 and the small pitch portion 52. Therefore, it is possible to avoid a sudden change in hardness of the distal shaft 33 and prevent it from breaking.

Further, in the present embodiment, since the proxyal shaft 34 is welded to the large pitch portion 50 and the small pitch portion 52 on the proximal end side, the welding region of the proxyal shaft 34 can be increased. Therefore, the possibility that the proximal shaft 34 is peeled off can be reduced.

Further, in the present embodiment, since one end of the proximal shaft 34 is fixed at at least two or more points of the large pitch portion 50, one end of the proximal shaft 34 is fixed from the fixed position located on the tip side where the load is most applied. Even if the portion is peeled off, the proximal shaft 34 and the distal shaft 33 are not immediately separated.

Further, in the present embodiment, one end of the proximity shaft 34 is welded at every one intersection at the large pitch portion 50 and at every two or more intersections at the small pitch portion 52 among the plurality of intersections. To. In this case, one end of the proximal shaft 34 is easier to manufacture than when the large pitch portion 50 and the small pitch portion 52 are welded at each of the plurality of intersections.

Further, in the present embodiment, by setting the acute angle α of 25 ° or more and 70 ° or less in the large pitch portion 50, the tensile strength of the distal shaft 33 in the longitudinal direction is improved as the acute angle α approaches 90 °. As the acute angle α approaches 0 °, the flexibility of the distal shaft 33 improves and it becomes easier to move in the radial direction.

(Other embodiments)
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example:

In the above embodiment, the gradual change pitch portion 51 is provided between one small pitch portion 52 and the large pitch portion 50 and between the other small pitch portion 52 and the large pitch portion 50. Not limited to, a gradual pitch portion 51 is provided between one small pitch portion 52 and the large pitch portion 50 and between at least one between the other small pitch portion 52 and the large pitch portion 50. It may be provided.

Further, in the above embodiment, one end of the proxyal shaft 34 is fixed to the large pitch portion 50 of the reinforcing layer 36 and the small pitch portion 52 on the proximal end side, but the present invention is not limited to this. In addition to these, one end of the proximal shaft 34 may be fixed to the gradually changing pitch portion 51 on the tip side, or may be fixed only to the large pitch portion 50.

Further, in the above embodiment, the support catheter 1 in which one end of the proximal shaft 34 is fixed to the large pitch portion 50 of the reinforcing layer 36 has been described, but the present invention is not limited to this, and the fixed member is formed in the tube. It may be fixed to a large pitch portion of the reinforcing layer. Specifically, as shown in FIG. 9, the tube 100 is provided on the tubular inner layer 135 and the outer surface of the inner layer 135, and a plurality of metal wires 36a are wound in one direction and the other direction to form a tubular mesh. A reinforcing layer 36 formed in a shape is provided. The reinforcing layer 36 includes a small pitch portion 52, a gradual change pitch portion 51, and a large pitch portion 50 as described above. The tube 100 further includes a fixed member 134 fixed to the large pitch portion 50. The tube 100 may be provided with a tubular outer layer on the outside of the reinforcing layer 36. Such a tube 100 has the same effect as the support catheter 1 described above.

Further, in the above embodiment, the tip 38 is provided at the tip of the distal shaft 33, but when the tip 38 is welded to the reinforcing layer 36 of the distal shaft 33, the portion including the welding point is more than the rest. It may be configured in a large pitch portion having a large braid pitch.

1 Support catheter 4 Guiding catheter 5 Balloon catheter 33 Distal shaft 34 Proximal shaft 35,135 Inner layer 36 Reinforcing layer 36a Metal wire 37 Outer layer 50 Large pitch part 51 Slow pitch part 52 Small pitch part 100 Tube 134 Fixed member

Claims (6)

Used with a therapeutic catheter for treating a treatment site and a guiding catheter into which the therapeutic catheter is inserted and for guiding the therapeutic catheter in a blood vessel, from the proximal opening of the guiding catheter. A support catheter that has a length that is inserted and protrudes from the distal opening of the guiding catheter, and guides the distal end portion of the therapeutic catheter to the therapeutic site.
It is formed in a tubular shape into which the therapeutic catheter can be inserted, and includes an inner layer and a reinforcing layer formed by winding a plurality of metal wires in one direction and the other direction to form a tubular mesh shape. The distal shaft that is composed and
The proximal shaft connected to the distal shaft is provided.
The reinforcing layer includes a small pitch portion in which the pitch of the wound metal wire is the first value, and a large pitch portion in which the pitch of the wound metal wire is a second value larger than the first value. Including
A support catheter in which one end of the proximal shaft is fixed to the large pitch portion. The support catheter according to claim 1, wherein the reinforcing layer includes two small pitch portions and the large pitch portion located between the two small pitch portions. A gradual change pitch portion is included between the small pitch portion and the large pitch portion.
The support catheter according to claim 1 or 2, wherein the gradually changing pitch portion reduces the pitch of the wound metal wire from the large pitch portion toward the small pitch portion. One end of the proximity shaft is a plurality of intersections in the large pitch portion where the metal wire wound in one direction and the metal wire wound in the other direction intersect and are lined up in the axial direction. The support catheter according to any one of claims 1 to 3, which is fixed at at least two or more intersections. The acute angle formed by the wound metal wire and the straight line perpendicular to the longitudinal direction of the inner layer in the large pitch portion in a normal state is 25 ° or more and 70 ° or less, according to any one of claims 1 to 4. The support catheter described. With a tubular inner layer,
A reinforcing layer provided on the outer surface of the inner layer and formed in a tubular mesh shape by winding a plurality of metal wires in one direction and the other direction is provided.
The reinforcing layer includes a small pitch portion in which the pitch of the wound metal wire is the first value, and a large pitch portion in which the pitch of the wound metal wire is a second value larger than the first value. Including
A tube further provided with a fixed member fixed to the large pitch portion.

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