WO2022249412A1

WO2022249412A1 - Catheter

Info

Publication number: WO2022249412A1
Application number: PCT/JP2021/020289
Authority: WO
Inventors: 雄太中川
Original assignee: 朝日インテック株式会社
Priority date: 2021-05-27
Filing date: 2021-05-27
Publication date: 2022-12-01

Abstract

The purpose of the present invention is to make it possible to appropriately guide a retrograde guide wire to the base end side. The present invention provides a catheter 1 comprising a mesh member 110, a hollow shaft 120 connected to the base end part of the mesh member 110, a distal-end tip 130, and a core wire 150 extending through the mesh member 110 and the hollow shaft 120 so that the distal end part thereof is connected to the distal end part of the mesh member 110 and the base end thereof is located farther on the base end side than the base end of the hollow shaft 120. The hollow shaft 120 has a center shaft 123 that has a core wire lumen 125 through which a core wire 150 is inserted and a guide wire lumen 124 through which a retrograde guide wire is inserted. A coil part 152 is formed on the core wire 150 in a range on the base end side of a position on the distal end side relative to the distal-end-side opening of the core wire lumen 125 when the mesh member 110 is in an expanded state.

Description

catheter

The present invention relates to catheters.

As a medical device for improving blood flow by removing obstructions that block blood vessels such as chronic total occlusion (CTO) A technique is known in which a guide wire is passed through and the guide wire is captured by a mesh-like extension part provided in a catheter (see, for example, Patent Document 1).

In Patent Literature 1, by providing a membrane body made of a flexible material that partially covers the gap of the expansion part, the guide wire inserted into the internal space of the expansion part is prevented from protruding outside the expansion part. A technique for doing so is disclosed.

JP 2019-72301 A

According to the technique described in Patent Document 1, the guide wire (retrograde guide wire) from the opposite side of the obstructing lesion is suppressed by the membrane body from protruding outside the extension portion, and the guide wire is attached to the shaft portion. can lead. However, even if the guide wire can be guided to the shaft portion, there is a possibility that the guide wire cannot be properly guided to the proximal end side if the guide wire comes into contact with the core wire or parts inside the shaft portion.

The present invention has been made based on the circumstances as described above, and its purpose is to provide a technique capable of appropriately guiding a retrograde guidewire to the proximal side.

In order to achieve such an object, a catheter according to one aspect includes a radially expandable and contractible tubular mesh member, a hollow shaft connected to the proximal end of the mesh member, and a distal end of the mesh member. a connected hollow distal tip, the mesh member such that the distal end is connected to the distal end of the mesh member and/or the distal tip, and the proximal end is positioned proximally relative to the proximal end of the hollow shaft; and a core wire extending through the interior of the hollow shaft, wherein the hollow shaft has an inner side having a core wire lumen through which the core wire passes and a guide wire lumen through which a retrograde guide wire guided from the distal side passes. A shaft is provided, and the core wire has a strand extending from a position on the distal side of the inlet on the distal side of the core wire lumen to the proximal side of the inlet when the mesh member is in an expanded state. A coil portion is formed by winding the .

In the catheter described above, the coil portion may be provided to a range that is closer to the proximal side than the inlet of the core wire lumen when the mesh member is in a diameter-reduced state.

Further, in the above catheter, the core wire lumen may be formed so that the inner diameter of the core wire lumen becomes smaller toward the distal end within a predetermined range on the distal end side.

According to the present invention, the retrograde guidewire can be appropriately guided to the proximal side.

FIG. 1 is a schematic cross-sectional view of a catheter according to the first embodiment. FIG. 2 is a cross-sectional view of the catheter according to the first embodiment taken along line AA. FIG. 3 is a cross-sectional view enlarging a part of the catheter according to the first embodiment. FIG. 4 is a schematic cross-sectional view of a state in which the mesh member of the catheter according to the first embodiment is expanded. FIG. 5 is a partially enlarged cross-sectional view of the catheter according to the first embodiment in which the mesh member is expanded. FIG. 6 is a schematic cross-sectional view of a catheter according to a second embodiment. FIG. 7 is a cross-sectional view of the catheter according to the second embodiment taken along line BB. FIG. 8 is a cross-sectional view enlarging a part of the catheter according to the second embodiment. FIG. 9 is a schematic cross-sectional view of a catheter according to a third embodiment; FIG. 10 is a cross-sectional view of the catheter according to the third embodiment taken along line CC. FIG. 11 is a cross-sectional view enlarging a part of the catheter according to the third embodiment. FIG. 12 is a schematic cross-sectional view of a catheter according to a fourth embodiment; FIG. 13 is a schematic cross-sectional view showing a state in which the mesh member of the catheter according to the fourth embodiment is expanded. FIG. 14 is a partially enlarged cross-sectional view of the catheter according to the fourth embodiment. FIG. 15 is a partially enlarged cross-sectional view of the catheter according to the fourth embodiment in which the mesh member is expanded. FIG. 16 is a schematic cross-sectional view of a catheter according to a fifth embodiment; FIG. 17 is a schematic cross-sectional view showing a state in which the mesh member of the catheter according to the fifth embodiment is expanded. FIG. 18 is a cross-sectional view enlarging a portion of the catheter according to the fifth embodiment. FIG. 19 is a partially enlarged cross-sectional view of the catheter according to the fifth embodiment in which the mesh member is expanded.

Although a catheter according to embodiments will be described with reference to the drawings, the present invention is not limited only to the embodiments described in the drawings. In addition, the dimensions of the catheter shown in each drawing are for the purpose of facilitating understanding of the implementation, and do not correspond to the actual dimensions.

In the present specification, the term "guide wire" refers to a medical guide wire that is pushed into a surgical site in a body cavity such as a blood vessel and used for guiding a catheter to the surgical site or for penetrating an obstruction. means

Also, in this specification, the term "distal side" means the direction along the longitudinal direction of the catheter (the direction along the axial direction of the catheter), which is the direction in which the distal tip is located with respect to the mesh member. In addition, the term "proximal side" means a direction along the longitudinal direction of the catheter, which is opposite to the distal side. In addition, the term “distal end” refers to the distal end of any member or site, and the term “basal end” refers to the proximal end of any member or site. In addition, the “maximum expansion diameter” means the outer diameter of a portion where the outer diameter of the mesh member perpendicular to the axial direction is the maximum when the mesh member is expanded (also referred to as “diameter expansion”).

Further, in the present specification, the term "anterograde guidewire" refers to a guidewire that is pushed to an operation site such as an obstruction site in a blood vessel prior to a catheter, and is referred to as a "retrograde guidewire." The term "guide wire" refers to a guide wire that is advanced from the distal end side of a catheter toward the catheter in a blood vessel, for example.

[First embodiment]
FIG. 1 is a schematic cross-sectional view of a catheter according to the first embodiment. FIG. 1 shows a state in which the diameter of the mesh member is reduced in the catheter. FIG. 2 is a cross-sectional view of the catheter according to the first embodiment taken along line AA. FIG. 3 is a cross-sectional view enlarging a part of the catheter according to the first embodiment. FIG. 4 is a schematic cross-sectional view of a state in which the mesh member of the catheter according to the first embodiment is expanded. FIG. 5 is a partially enlarged cross-sectional view of the catheter according to the first embodiment in which the mesh member is expanded.

The catheter 1 generally comprises a mesh member 110, a hollow shaft 120, a distal tip 130, a core wire 150, a guiding membrane 160 and a connector 170.

The mesh member 110 is a radially expandable tubular member. When the core wire 150 is pulled proximally, the mesh member 110 expands by deforming out of plane and bulging radially outward as shown in FIG. to receive retrograde guidewire W 2 within mesh member 110 .

In this embodiment, the mesh member 110 has a plurality of first strands 111 and a plurality of second strands 112, and the first strands 111 and the second strands 112 are woven in a grid pattern. It is rarely formed to be tubular as a whole. The mesh member 110 is formed with apertures m between adjacent braided strands and receives a retrograde guidewire through the enlarged apertures m when expanded. A distal end portion of each wire constituting mesh member 110 is joined to distal tip 130 , and a proximal end portion of each wire is joined to hollow shaft 120 . Each of the

wires

111 and 112 may be a single wire, or may be a twisted wire obtained by twisting a plurality of single wires.

A metal material or a resin material can be used as a material for forming the

wires

111 and 112 of the mesh member 110 . Examples of such metal materials include stainless steel such as SUS304, nickel-titanium alloys, cobalt-chromium alloys, and the like. Examples of such resin materials include polyamide, polyester, polyacrylate, polyetheretherketone, and the like. Among these materials, metal materials may be used from the viewpoint of improving strength and flexibility. The

wires

111 and 112 may be made of the same material, or may be made of different materials.

In addition, from the viewpoint of improving the visibility of the mesh member 110, a radiopaque material may be included as a material for forming the

strands

111 and 112 of the mesh member 110. Examples of such radiopaque materials include gold, platinum, tungsten, or alloys containing these elements (eg, platinum-nickel alloys, etc.). The surface of each

strand

111, 112 may be coated with a radiopaque material.

The hollow shaft 120 is connected to the proximal end of the mesh member 110. In this embodiment, the hollow shaft 120 includes a hollow distal shaft 121 whose distal end is connected to the proximal end of the mesh member 110, and a hollow central shaft 121 whose distal end is connected to the proximal side of the distal shaft 121. It has a shaft 123 and a hollow proximal shaft 127 whose distal end is connected to the proximal end of central shaft 123 .

The distal shaft 121 has a single lumen 122 through which the retrograde guidewire W2 and the core wire 150 can be passed.

The central shaft 123 is an example of an inner shaft, has an outer diameter corresponding to the inner diameter of the distal shaft 121, and, as shown in FIGS. is connected to the inner circumference of the

The central shaft 123 has a guidewire lumen 124 through which a retrograde guidewire can be passed, and a corewire lumen 125 through which a corewire 150 can be passed. As shown in FIG. 2, the guide wire lumen 124 has a circular front surface that is partially cut away, and the core wire lumen 125 has a circular front surface. As described above, since the core wire lumen 125 through which the core wire 150 can be inserted is provided, the operability of expanding and contracting the mesh member 110 by the core wire 150 can be improved.

An opening 126 that opens toward the proximal side is formed on the proximal side of the guide wire lumen 124 of the central shaft 123 , and the retrograde guide wire is delivered to the outside of the catheter 1 through the opening 126 . be.

The tip surface 123a on the tip side of the central shaft 123 is arranged at a position closer to the proximal side than the tip side of the tip side shaft 121, as shown in FIGS. A tip surface 123 a of the central shaft 123 is a surface that is inclined with respect to the axis of the hollow shaft 120 . The distal end surface 123 a is positioned so that the surface surrounding the core wire lumen 125 is closer to the distal end than the surface surrounding the guide wire lumen 124 . In addition, in this embodiment, the tip surface 123a is a flat surface. With this configuration, the central shaft 123 can be easily produced by cutting the tip side from a cylindrical state with a plane inclined with respect to the axis. Note that the tip surface 123a is not limited to a flat surface, and may be a curved surface.

In this way, since the distal end surface 123a of the central shaft 123 is a surface that is inclined with respect to the axis of the hollow shaft 120, the guide wire lumen 124 is positioned in a plane perpendicular to the axis of the hollow shaft 120 on the distal side. A part of the periphery (peripheral wall) can be made absent, and the ratio of the area of the part connected to the guide wire lumen 124 to the lumen 122 in the plane perpendicular to the axis of the hollow shaft 120 is increased. and effectively guide a retrograde guidewire into the guidewire lumen 124 . A retrograde guidewire can also be effectively guided into the guidewire lumen 124 by an inclination around the guidewire lumen 124 . The slope around corewire lumen 125 can also effectively guide a retrograde guidewire into guidewire lumen 124 .

The proximal side shaft 127 is connected to the proximal side of the central shaft 123 . The proximal shaft 127 internally communicates with the core wire lumen 125 of the central shaft 123 and has a lumen 128 through which the core wire 150 can be inserted.

As the material for the hollow shaft 120, since the hollow shaft 120 is inserted into the blood vessel, it may have antithrombotic properties, flexibility, and biocompatibility, and a resin material and a metal material are adopted. be able to. Since the distal shaft 121 and the central shaft 123 are required to be flexible, resin materials such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluorine resin may be used. As the base end side shaft 127, a metal tube such as a hypotube may be adopted because it is required to have pushability.

The distal tip 130 is a member connected to the distal end of the mesh member 110 . Specifically, the tip 130 is sharpened toward the distal side so that the catheter 1 can easily advance through the blood vessel. Each tip is embedded.

The material forming the distal tip 130 may be flexible because the catheter 1 is advanced through the blood vessel. Materials having such flexibility include, for example, resin materials such as polyurethane and polyurethane elastomer.

The core wire 150 is connected at its distal end to the distal end of the mesh member 110 and/or the distal tip 130, and extends through the interior of the mesh member 110 and the hollow shaft 120 such that its proximal end is positioned proximally relative to the proximal end of the hollow shaft 120. extends through. Specifically, the core wire 150 passes through the space inside the mesh member 110, the inside of the hollow shaft 120 (the lumen 122 of the distal shaft 121, the core wire lumen 125 of the central shaft 123, and the lumen 128 of the proximal shaft 127). , and through a through hole 171 of the connector 170 to the outside. By manipulating the core wire 150 outside the connector 170, the core wire 150 advances and retreats in the axial direction, and the mesh member 110 expands and contracts in the radial direction.

The core wire 150 includes a distal end portion 151 whose distal end is connected to the distal end of the mesh member 110 and/or the distal tip 130, a coil portion 152 connected to the proximal end side of the distal end portion 151, and a coil portion 152 connected to the proximal end side of the coil portion 152. It has a proximal end 153 to which it is connected. The tip portion 151 is composed of, for example, one metal wire. The coil part 152 has, for example, a cylindrical hollow shape wound with one or more metal wires. The outer diameter of the coil portion 152 is larger than the outer diameter of the tip portion 151 . Thereby, for example, as shown in FIG. 2, the gap between the core wire lumen 125 and the outside of the coil portion 152 can be reduced. The outer diameter of the coil portion 152 is preferably, for example, substantially the same as or close to the inner diameter of the core wire lumen 125 . With this configuration, the outer diameter of the core wire 150 can be increased while maintaining the bendability of the core wire 150, and the gap between the core wire lumen 125 and the core wire lumen 125 can be reduced.

As shown in FIG. 3, when the mesh member 110 is in a reduced diameter state, that is, when the core wire 150 is not pulled to the proximal side, the coil portion 152 extends at least on the distal side of the core wire lumen 125. It is provided in a range from a position on the distal side of the inlet to the proximal side of the core wire lumen 125 on the distal side. Further, as shown in FIG. 5, the coil portion 152 is at least on the distal side of the core wire lumen 125 even when the mesh member 110 is in an expanded state, that is, when the core wire 150 is pulled to the proximal side. is provided in a range from a position on the distal side of the inlet of the core wire lumen 125 to a proximal side of the core wire lumen 125 on the distal side. With such a configuration, when the mesh member 110 is in the expanded state, the coil portion 152 is positioned at the entrance of the core wire lumen 125, and the gap between the core wire lumen 125 and the coil portion 152 is provided. can be made smaller. This can prevent the end of the retrograde guidewire from straying into the core wire lumen 125 . As a result, breakage of the retrograde guidewire can be prevented.

The material constituting the core wire 150 may have sufficient tensile strength and rigidity from the viewpoint of preventing the core wire 150 itself from being cut and expanding and contracting the mesh member 110 reliably. Examples of such materials include stainless steel such as SUS304, metal materials such as nickel-titanium alloys, and cobalt-chromium alloys.

The connector 170 is a member for gripping the catheter 1 by the operator. The connector 170 is connected to the proximal end of the hollow shaft 120 and connects the lumen 122 of the distal shaft 121 of the hollow shaft 120, the core wire lumen 125 of the central shaft 123, and the proximal end so that the core wire 150 can be exposed to the outside. It has a through hole 171 communicating with the lumen 128 of the side shaft 127 and an opening 172 formed at the proximal end of the through hole 171 . The shape of the connector 170 is not particularly limited, and may be any shape as long as the operator can easily hold it.

The guide membrane 160 is arranged on the mesh member 110 , and the tip of the guide membrane 160 is positioned between the proximal end of the distal tip 130 and the tip of the hollow shaft 120 . Guiding membrane 160 acts to smoothly guide a retrograde guidewire received through opening m of mesh member 110 toward hollow shaft 120 . The guiding membrane 160 of the present embodiment extends from the substantially central portion in the axial direction of the mesh member 110 where the tip is located (for example, the maximum expanded diameter portion of the mesh member 110) to the tip of the hollow shaft 120 where the proximal end of the guiding membrane 160 is located. It is formed in the mesh member 110 in a region spanning Here, when a retrograde guidewire is to be received in the catheter 1, the mesh member 110 is expanded as shown in FIG. 4, and the guiding membrane 160 is deployed in a funnel shape. Retrograde guidewire W2 is received within mesh member 110 through opening m of mesh member 110 and is directed into hollow shaft 120 against, for example, funneled guide membrane 160 .

The induction film 160 is made of a stretchable material. Examples of materials forming the guide film 160 include resin materials such as polyurethane, polyurethane elastomer, polyamide, polyamide elastomer, and copolymers thereof.

Next, the mode of use of the catheter 1 will be explained. Catheter 1 is used to receive retrograde guidewire W2.

First, after inserting an antegrade guide wire W1 (not shown) into, for example, a blood vessel, it is advanced along the blood vessel to a site where an obstruction exists (hereinafter also referred to as "occlusion site").

Next, after the distal end of the antegrade guidewire W1 reaches the occlusion site, the proximal end of the antegrade guidewire W1 is inserted into the distal end of the distal tip 130 and the lumen of the hollow shaft 120 (lumen 122, guidewire lumen 124). Using the antegrade guidewire W1 as a guide, the distal end of the catheter 1 is advanced in the blood vessel to the occlusion site. At this time, the mesh member 110 is inserted into the blood vessel in a diameter-reduced state, and the diameter-reduced state is maintained until the tip of the catheter 1 reaches the occlusion site.

Next, after the distal end of the catheter 1 reaches the occlusion site, the antegrade guide wire W1 is pulled out from the catheter 1 by pulling the antegrade guide wire W1 toward the proximal end side. Note that the antegrade guidewire W1 may not be pulled out from the catheter 1.

Next, by pulling the core wire 150 exposed to the outside of the connector 170 toward the proximal end side, the distance between the distal end of the mesh member 110 and the distal end of the hollow shaft 120 is narrowed, and as a result, the mesh member 110 faces radially outward. Transform and expand. At this time, as the mesh member 110 is expanded, the opening m is also expanded, so that the retrograde guidewire W2 can be easily received. In this embodiment, since the tip of the induction film 160 is joined to the substantially central portion in the axial direction of the mesh member 110, the induction film 160 is expanded following the expansion of the mesh member 110, and the induction film 160 is expanded as a whole. becomes a funnel shape. Also, at this time, the coil portion 152 of the core wire 150 is positioned at the entrance of the core wire lumen 125, and the gap between the core wire lumen 125 and the coil portion 152 is small.

Next, as shown in FIG. 4, the catheter 1 receives the retrograde guidewire W2 coming from the distal end side. As the path through which the retrograde guidewire W2 is directed, for example, a false lumen in the blood vessel wall surrounding the occlusion site, a through hole passing through the occlusion site, etc. are assumed, but any path may be used. After being received in the space inside mesh member 110 through opening m of expanded mesh member 110, retrograde guide wire W2 is guided by guide membrane 160 of mesh member 110 and is guided from opening 120a of hollow shaft 120 to the distal end. It is inserted through the lumen 122 of the side shaft 121 . The retrograde guidewire W2 is effectively guided from the lumen 122 of the distal shaft 121 to the guidewire lumen 124 due to the shape of the distal side of the central shaft 123 without straying into the guidewire lumen 125, and is guided to the opening 126. is delivered to the outside of the catheter 1 via the Next, the retrograde guidewire W2 delivered from the opening 126 is delivered outside the body after passing through the blood vessel. As a result, it is possible to create a state in which the retrograde guide wire W2 passes through the obstructed site and both ends of the retrograde guide wire W2 are exposed to the outside of the body.

Thus, the catheter 1 can receive the retrograde guidewire W2 and guide the end portion out of the body, so it can be suitably used as a medical device in combination with the retrograde guidewire W2.

As described above, since the catheter 1 has the above-described configuration, it is possible to prevent the retrograde guide wire W2 guided through the lumen 122 of the distal shaft 121 from straying into the core wire lumen 125. Wire W2 can be effectively guided into guidewire lumen 124 and delivered to the outside through opening 126 .

[Second embodiment]
Next, a catheter 1A according to a second embodiment will be described. FIG. 6 is a schematic cross-sectional view of a catheter according to a second embodiment. FIG. 7 is a cross-sectional view of the catheter according to the second embodiment taken along line BB. FIG. 8 is a cross-sectional view enlarging a part of the catheter according to the second embodiment. In addition, the same code|symbol is attached|subjected about the part similar to the catheter 1 which concerns on 1st Embodiment.

A catheter 1A according to the second embodiment includes a hollow shaft 220 instead of the hollow shaft 120 of the catheter 1 according to the first embodiment, and a core wire 250 instead of the core wire 150.

The core wire 250 is made of, for example, one metal wire. The outer diameter of the tip portion of the core wire 250 is formed, for example, so as to decrease toward the tip. The material comprising core wire 250 may be similar to core wire 150 .

The hollow shaft 220 further has a coil portion 129 connected to the inner periphery of the core wire lumen 125 in addition to the configuration of the hollow shaft 120 . The coil portion 129 has, for example, a cylindrical hollow shape wound with one or more metal wires. The coil portion 129 may be provided over the entire core wire lumen 125 in the axial direction, or may be provided in a portion of the core wire lumen 125 on the distal end side. According to the coil portion 129, for example, as shown in FIGS. 7 and 8, the gap between the core wire lumen 125 and the core wire 250 can be reduced. The inner diameter of the coiled portion 129 may be, for example, the same as or slightly larger than the maximum outer diameter of the portion of the core wire 250 that passes through that portion of the coiled portion 129 when the mesh member 110 is expanded or contracted. With this configuration, the outer diameter of the core wire 250 can be reduced to maintain flexibility, the gap between the core wire 250 and the core wire lumen 125 can be reduced, and the core wire lumen 125 can be retrograde. It is possible to appropriately prevent the guide wire from getting into the wrong place.

[Third Embodiment]
Next, a catheter 1B according to a third embodiment will be described. FIG. 9 is a schematic cross-sectional view of a catheter according to a third embodiment; FIG. 10 is a cross-sectional view of the catheter according to the third embodiment taken along line CC. FIG. 11 is a cross-sectional view enlarging a part of the catheter according to the third embodiment. Parts similar to those of the catheters according to the first and second embodiments are denoted by the same reference numerals.

A catheter 1B according to the third embodiment includes a hollow shaft 320 instead of the hollow shaft 120 of the catheter 1A according to the second embodiment.

The hollow shaft 320 is connected to the proximal end of the mesh member 110. In this embodiment, the hollow shaft 320 includes a distal shaft 121 , a hollow central shaft 323 whose distal end is connected to the proximal side of the distal shaft 121 , and a distal end connected to the proximal end of the central shaft 323 . and a hollow proximal shaft 127 .

The central shaft 323 is an example of an inner shaft, has an outer diameter corresponding to the inner diameter of the distal shaft 121, and, as shown in FIGS. connected inside the

The central shaft 323 has a guidewire lumen 324 through which a retrograde guidewire can be passed and a corewire lumen 325 through which a corewire 250 can be passed. As shown in FIG. 10, the guide wire lumen 324 has a circular front surface with a part cut away, and the core wire lumen 325 has a circular front surface. As described above, since the core wire lumen 325 through which the core wire 250 can be inserted is provided, the operability of expanding and contracting the mesh member 110 by the core wire 250 can be improved.

An opening 326 that opens toward the proximal side is formed on the proximal side of the guidewire lumen 324 of the central shaft 323, and the retrograde guidewire is delivered to the outside of the catheter 1B through the opening 326. be.

The tip surface 323a on the tip side of the central shaft 323 is arranged at a position closer to the proximal side than the tip side of the tip side shaft 121, as shown in FIGS. A tip surface 323 a of the central shaft 323 is a surface that is inclined with respect to the axis of the hollow shaft 320 . The distal surface 323 a has a surface surrounding the core wire lumen 325 that is closer to the distal side than a surface surrounding the guide wire lumen 324 . In addition, in this embodiment, the tip surface 323a is a flat surface. With this configuration, the central shaft 323 can be easily produced by cutting the tip side from a cylindrical state with a plane inclined with respect to the axis. Note that the tip surface 323a is not limited to a flat surface, and may be a curved surface.

The core wire lumen 325 is formed so that the inner diameter becomes smaller toward the distal end. The inner diameter of each portion of core wire lumen 325 is, for example, equal to or slightly larger than the maximum outer diameter of the portion of core wire 250 that passes through core wire lumen 325 when mesh member 110 is expanded or contracted. good too. With this configuration, the outer diameter of the core wire 250 can be reduced to maintain flexibility, and the gap on the distal side between the core wire 250 and the core wire lumen 325 can be reduced. It is possible to adequately prevent the erroneous insertion of the guidewire.

In this way, since the distal end surface 323a of the central shaft 323 is a surface that is inclined with respect to the axis of the hollow shaft 320, the guide wire lumen 324 is positioned in a plane perpendicular to the axis of the hollow shaft 320 on the distal side. A portion of the peripheral surface can be absent, and the ratio of the area leading to the guidewire lumen 324 to the lumen 122 in the plane perpendicular to the axis of the hollow shaft 320 can be increased to provide a retrograde guide. A wire can be effectively guided to the guidewire lumen 324 . A retrograde guidewire can also be effectively guided into the guidewire lumen 324 by an inclination around the guidewire lumen 324 . The slope around corewire lumen 325 can also effectively guide a retrograde guidewire into guidewire lumen 324 .

As the material for the hollow shaft 320, since the hollow shaft 320 is inserted into the blood vessel, it may have antithrombotic properties, flexibility, and biocompatibility, and a resin material or a metal material is adopted. be able to. Since the distal shaft 121 and the central shaft 323 are required to be flexible, resin materials such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluorine resin may be used. As the base end side shaft 127, a metal tube such as a hypotube may be adopted because it is required to have pushability.

[Fourth embodiment]
Next, a catheter 1C according to a fourth embodiment will be described. FIG. 12 is a schematic cross-sectional view of a catheter according to a fourth embodiment; FIG. 13 is a schematic cross-sectional view showing a state in which the mesh member of the catheter according to the fourth embodiment is expanded. FIG. 14 is a partially enlarged cross-sectional view of the catheter according to the fourth embodiment. FIG. 15 is a partially enlarged cross-sectional view of the catheter according to the fourth embodiment in which the mesh member is expanded. Parts similar to those of the catheters according to the first to third embodiments are denoted by the same reference numerals.

A catheter 1C according to the fourth embodiment includes a core wire 350 instead of the core wire 150 of the catheter 1 according to the first embodiment.

The core wire 350 is made of, for example, one metal wire. The outer diameter of the tip portion of the core wire 350 is formed, for example, so as to decrease toward the tip. The material comprising core wire 350 may be similar to core wire 150 .

The core wire 350 has a protrusion 351 brazed with a metal brazing material. 12 and 14, when the mesh member 110 is in a state of reduced diameter, i.e., when the core wire 350 is not pulled to the proximal side, the convex portion 351 is positioned at the distal end of the core wire lumen 125. 13 and 15, when the mesh member 110 is in an expanded state, that is, when the core wire 350 is pulled proximally, the core wire lumen 125 is provided at a position corresponding to the entrance on the tip side of the . The protrusion 351 is provided, for example, on the guide wire lumen 124 side of the core wire 350 . As shown in FIGS. 13 and 15, when the mesh member 110 is in the expanded state, the protrusion 351 is caught in the entrance of the core wire lumen 125, preventing the core wire 350 from moving further proximally. It is the size of

Such a configuration can prevent the core wire 350 from being excessively pulled proximally, causing the mesh member 110 to expand more than necessary or the core wire 350 to come off the distal tip 130 or the mesh member 110. It can prevent you from getting tired. In addition, since the protrusion 351 closes at least part of the gap between the core wire lumen 125 and the core wire 350 , it is possible to prevent the end of the retrograde guidewire from entering the core wire lumen 125 . As a result, breakage of the retrograde guidewire can be prevented.

[Fifth embodiment]
Next, a catheter 1D according to the fifth embodiment will be described. FIG. 16 is a schematic cross-sectional view of a catheter according to a fifth embodiment; FIG. 17 is a schematic cross-sectional view showing a state in which the mesh member of the catheter according to the fifth embodiment is expanded. FIG. 18 is a cross-sectional view enlarging a portion of the catheter according to the fifth embodiment. FIG. 19 is a partially enlarged cross-sectional view of the catheter according to the fifth embodiment in which the mesh member is expanded. Parts similar to those of the catheters according to the first to fourth embodiments are denoted by the same reference numerals.

A catheter 1D according to the fifth embodiment includes a core wire 450 instead of the core wire 150 of the catheter 1 according to the first embodiment.

The core wire 450 is connected to the distal end of the mesh member 110 and/or the distal tip 130 at its distal end, and extends through the interior of the mesh member 110 and the hollow shaft 120 such that its proximal end is positioned proximally relative to the proximal end of the hollow shaft 120 . extends through. Specifically, the core wire 450 passes through the space inside the mesh member 110, the inside of the hollow shaft 120 (the lumen 122 of the distal shaft 121, the core wire lumen 125 of the central shaft 123, and the lumen 128 of the proximal shaft 127). , and through a through hole 171 of the connector 170 to the outside. By manipulating the core wire 450 outside the connector 170, the core wire 450 advances and retreats in the axial direction, and the mesh member 110 expands and contracts in the radial direction.

The core wire 450 has a distal end portion 451 whose distal end is connected to the distal end of the mesh member 110 and/or the distal tip 130 and a proximal end portion 452 connected to the proximal side of the distal end portion 451 .

The base end portion 452 is formed of, for example, one metal wire. The tip portion 451 is, for example, cylindrical. The outer diameter of the distal end portion 451 is larger than the outer diameter of the proximal end portion 452 . Also, the outer diameter of the distal end portion 451 is larger than the inner diameter of the core wire lumen 125 . As shown in FIGS. 16 and 18, the distal end portion 451 is the distal end portion of the core wire lumen 125 when the mesh member 110 is in a reduced diameter state, that is, when the core wire 450 is not pulled proximally. When the mesh member 110 is in a predetermined expanded state, that is, when the core wire 450 is pulled proximally, as shown in FIGS. It is provided at a position corresponding to the inlet on the distal end side of the lumen 125 . As shown in FIGS. 17 and 19, when the mesh member 110 is in the expanded state, the distal end portion 451 blocks the entrance of the core wire lumen 125, allowing the core wire 450 to extend proximally. don't move. The material comprising core wire 450 may be similar to core wire 150 .

With such a configuration, when the mesh member 110 is in a predetermined expanded state, the distal end portion 451 of the core wire 450 fits into the entrance of the core wire lumen 125 on the distal side, thereby causing the core wire 450 to move excessively toward the proximal side. It is possible to prevent the mesh member 110 from being pulled excessively, and prevent the core wire 450 from being detached from the distal tip 130 or the mesh member 110 . In addition, since the distal end portion 451 fits into the entrance on the distal side of the core wire lumen 125 , it is possible to prevent the end of the retrograde guidewire from entering the core wire lumen 125 erroneously. As a result, breakage of the retrograde guidewire can be prevented.

In addition, the present invention is not limited to the configuration of the above-described embodiment, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims. be done.

For example, in the above-described first to fifth embodiments, the distal shafts 121, 321 and the

central shafts

123, 323 are configured separately and are joined together, but the present invention does this. However, the tip side shafts 121, 321 and the

central shafts

123, 323 may be integrally formed.

Further, in the above-described first embodiment, the coil portion 152 of the core wire 150 is configured only by a coil wound with a metal wire, but the present invention is not limited to this. It is also possible to adopt a configuration in which one or more metal wires are wound around one metal wire.

Also, the catheters of the first embodiment and the third embodiment described above may be combined.

In addition, in the first to fifth embodiments described above, the entire front surface of the

central shaft

123, 323 is a surface inclined with respect to the axis of the

hollow shaft

120, 320, but the present invention is not limited to this, For example, only the distal surface of the

central shaft

123, 323 around the

guidewire lumen

124, 324 may be angled with respect to the axis of the

hollow shaft

120, 320; The wire can be effectively guided through the guidewire lumen 124,324.

1, 1A, 1B, 1C, 1D Catheter 110

Mesh member

111, 112 Wire 120 Hollow shaft 121 Distal side shaft 123 Central shaft 123a Distal surface 124 Guidewire lumen 125 Core wire lumen 127 Proximal side shaft 130 Distal tip 150,250 , 350, 450 core wire 151 tip 152 coil 153 base 160 induction membrane

Claims

a radially expandable tubular mesh member;
a hollow shaft connected to the proximal end of the mesh member;
a hollow distal tip connected to the distal end of the mesh member;
through the interior of the mesh member and the hollow shaft such that the distal end is connected to the distal end of the mesh member and/or the distal tip, and the proximal end is positioned proximally relative to the proximal end of the hollow shaft. an extending core wire;
The hollow shaft has an inner shaft having a core wire lumen through which the core wire is inserted and a guide wire lumen through which a retrograde guide wire guided from the distal side is inserted,
A wire is wound around the core wire in a range from a position on the distal side of the inlet on the distal side of the core wire lumen to the proximal side of the inlet when the mesh member is in the expanded state. A catheter having a coiled portion.
2. The catheter according to claim 1, wherein the coil portion is provided in a range closer to the proximal side than the inlet of the core wire lumen when the mesh member is in a diameter-reduced state.
2. The catheter according to claim 1, wherein the core wire lumen is formed such that the inner diameter of the core wire lumen becomes smaller toward the distal end side in a predetermined range on the distal end side.