JP7805136B2 - Occlusion coil pusher - Google Patents

Description

The present invention relates to an occlusion coil pusher for pushing out occlusion coils used, for example, in the treatment of cerebral aneurysms.

For example, when treating cerebral arteries, multiple occlusion coils are filled into the aneurysm to block blood flow and prevent rupture. Also, when administering anti-cancer drugs, an occlusion coil is placed in a specific blood vessel among multiple branching blood vessels to block blood flow and allow the anti-cancer drug to flow more easily through other blood vessels, thereby treating the affected area.

The above-mentioned occlusion coil is typically made of a radiopaque material and is pushed out by a pusher to be placed in the desired location. During this process, the occlusion coil is pushed out with the pusher while the boundaries of the occlusion coil and pusher are visually confirmed under X-ray fluoroscopy (radiofluorography).

For example, Patent Document 1 below describes a pusher wire for a living body implantation device that includes a main wire and a spring coil attached to the outer periphery of the distal end of the main wire. The spring coil is made up of a radiopaque coil portion located at the distal end of the main wire and a radiolucent coil portion located adjacent to the proximal end of the radiopaque coil portion.

Patent No. 4463191

In the pusher wire for indwelling devices disclosed in Patent Document 1, the distal end of the spring coil is a radiopaque coil portion made of the same radiopaque material as the occlusive coil. This makes it difficult to visually identify the boundary between the occlusive coil and the radiopaque coil portion (the portion between the base end of the occlusive coil and the distal end of the radiopaque coil portion) under X-ray fluoroscopy, which can result in the placement of the occlusive coil taking a long time.

Therefore, an object of the present invention is to provide an occlusive coil pusher that makes it easier to see the boundary between the occlusive coil and the pusher under X-ray fluoroscopy, thereby improving the workability of the occlusive coil placement procedure.

To achieve the above objective, the present invention provides an occlusive coil pusher for pushing out an occlusive coil made of a radiopaque material placed inside a catheter. The pusher comprises a core wire having a base and a tip end whose diameter is smaller than the base end, and a pressing portion provided at the tip end of the core wire for pressing the occlusive coil. The pressing portion comprises at least one coil portion formed by winding a wire, and an X-ray transparent portion having an axial length of 1 to 5 mm and provided within a range of 10 mm from the tip of the pressing portion, with the portion adjacent to the X-ray transparent portion being an X-ray opaque portion.

According to the present invention, an X-ray transparent section with an axial length of 1 to 5 mm is provided within a range of 10 mm from the most distal end of the pressing section, and the portion adjacent to this X-ray transparent section is an X-ray opaque section. This makes it easier to visualize the boundary between the base end of the occlusion coil and the most distal end of the pressing section, thereby improving the workability of the occlusion coil placement procedure.

1 is a cross-sectional view showing a first embodiment of a pusher for an occlusion coil according to the present invention. FIG. FIG. 10 is an explanatory diagram illustrating the use of the occlusion coil pusher to push out an occlusion coil housed in a catheter. FIG. 10 is an X-ray fluoroscopic image of the occlusion coil pusher under X-ray fluoroscopy. FIG. 10 is an explanatory diagram of the state in which the occlusive coil has been pushed out to a predetermined location inside the body using the occlusive coil pusher. 1A and 1B show a comparative example of a pusher for an occlusion coil, in which FIG. 1A is a side view thereof and FIG. 1B is an X-ray fluoroscopy image thereof. 1A is a cross-sectional view showing a second embodiment of a pusher for an occlusive coil according to the present invention, and FIG. 1B is a cross-sectional view showing a third embodiment of a pusher for an occlusive coil according to the present invention. 10A and 10B show a fourth embodiment of the pusher for an occlusion coil according to the present invention, in which FIG. 10A is a cross-sectional view thereof, and FIG. 10B is an X-ray fluoroscopic image thereof under X-ray fluoroscopy.

(First embodiment of the pusher for the occlusion coil)
A first embodiment of a pusher for an occlusive coil according to the present invention will be described below with reference to FIGS.

As shown in Figure 4, for example, an occlusive coil 1 may be placed within an affected area A, such as an aneurysm occurring in a tubular organ V, such as a blood vessel, within a specific blood vessel among multiple branched blood vessels, or within the body for other specific purposes. This occlusive coil pusher 10 is used to push the occlusive coil 1 out of the catheter 5 (see Figure 2) that houses the occlusive coil 1. The occlusive coil 1 is formed by winding a wire made of an X-ray opaque material, such as W, Pt, Ti, Pd, Rh, Au, Ag, Bi, Ta, or an alloy thereof.

As shown in FIG. 1, the occlusive coil pusher 10 of this first embodiment (hereinafter simply referred to as "pusher 10") has a core wire 20 having a base 21 and a tip 23 that is smaller in diameter than the base 21, and a pressing portion 30 that is provided at the tip 23 of the core wire 20 and presses the occlusive coil 1.

In the following description, the "base end" or "base end" of each component, such as the core wire 20 or the pressing portion 30, refers to the end or end closest to the user's hand when using the occlusion coil pusher (proximal end), and the "tip end" or "tip" refers to the end or end opposite the base end or base end (distal end).

In this embodiment, the core wire 20 is a round wire with a circular cross section. It has a base portion 21 that extends a predetermined length with a constant outer diameter, and a tip portion 23 that is connected to the tip of the base portion 21 and has a smaller diameter than the base portion 21. The tip portion 23 consists of a first tapered portion 24 that extends from the tip of the base portion 21 while gradually reducing in diameter toward the tip of the core wire, a first straight portion 25 that extends linearly from the tip of the first tapered portion 24 with a constant outer diameter, a second tapered portion 26 that extends from the tip of the first straight portion 25 while gradually reducing in diameter toward the tip of the core wire, and a second straight portion 27 that extends linearly from the tip of the second tapered portion 26 with a constant outer diameter. In this embodiment, the tip 27a of the second straight portion 27 is the very tip of the core wire 20.

The pressing portion 30 has at least one coil portion 31 formed by winding a wire 31a, and an X-ray transparent portion 33 with an axial length L2 of 1 to 5 mm, located within a range of 10 mm from the tip 30a of the pressing portion 30 (see L1 in Figure 1). The portion adjacent to the X-ray transparent portion 33 forms an X-ray opaque portion.

More specifically, the pressing portion 30 in this embodiment has a coil portion 31 arranged around the second tapered portion 26 of the tip portion 23 of the core wire 20, and an X-ray transparent portion 33 arranged around the second straight portion 27 of the tip portion 23 of the core wire 20 and located closer to the tip in the axial direction of the core wire 20 than the coil portion 31.

In this embodiment, the coil portion 31 is formed by winding wire rod 31a made of an X-ray opaque material, such as W, Pt, Ti, Pd, Rh, Au, Ag, Bi, Ta, or an alloy thereof. This coil portion 31 constitutes the "X-ray opaque portion" of the present invention. Furthermore, the coil portion 31 in this embodiment is a loosely wound coil, wound with a predetermined gap P1 between adjacent wire rods 31a, 31a.

The coil portion 31, which constitutes the radiopaque portion, appears darker than the radiotransparent portion 33 under x-ray fluoroscopy; in this case, it appears black or close to black (see x-ray fluoroscopic image G3 in Figure 3). However, in this embodiment, the x-ray fluoroscopic image G3 of the radiopaque portion appears paler (brighter) than the x-ray fluoroscopic image G1 of the occlusion coil 1.

On the other hand, the X-ray transparent portion 33 is in the form of a coil formed by winding wire 33a made of an X-ray transparent material, such as an Fe-based alloy such as stainless steel or piano wire, copper, aluminum, chromium, nickel, titanium, or an alloy of these. Furthermore, the X-ray transparent portion 33 in this embodiment is a loosely wound coil formed by winding adjacent wires 33a, 33a with a predetermined gap P2 between them. Furthermore, the gap P2 between adjacent wires 33a, 33a in the X-ray transparent portion 33 is larger than the gap P1 between adjacent wires 31a, 31a in the coil portion 31.

In addition, in this embodiment, the wire diameter of the wire 33a forming the X-ray transparent portion 33 is the same as the wire diameter of the wire 31a forming the coil portion 31. Furthermore, in this embodiment, the outer diameter of the X-ray transparent portion 33 is the same as the outer diameter of the coil portion 31.

Under X-ray fluoroscopy, the X-ray transparent portion 33 appears brighter than the occlusion coil 1 and the X-ray opaque portion; in this case, it appears white or close to white (see X-ray fluoroscopy image G2 in Figure 3).

As shown in FIG. 1, the tip of the coil portion 31 and the base end of the X-ray transparent portion 33 are joined by a joint 35 made of a bonding material such as metal brazing or adhesive. As a result, the X-ray transparent portion 33 is located at the very tip of the pressing portion 30, and the coil portion 31, which constitutes the X-ray opaque portion, is located adjacent to the base end of the X-ray transparent portion 33 in the axial direction, via the joint 35. In other words, the coil portion 31, which is the X-ray opaque portion, is located adjacent to the base end of the X-ray transparent portion 33, via the joint 35.

Furthermore, as shown in FIG. 1, the radially inward side of the coil portion 31 and the X-ray transparent portion 33 is filled with a filler material 37, such as adhesive, synthetic resin, or wax. The coil portion 31 and the X-ray transparent portion 33 are fixed to predetermined locations on the tip portion 23 of the core wire 20 via this filler material 37.

The coil section 31 and the X-ray transparent section 33 are covered on their exterior with a cover 39 made of a resin film formed from, for example, polyurethane, polyether ether ketone (PEEK), nylon elastomer, polyether block amide, polyethylene, polyvinyl chloride, vinyl acetate, or a fluororesin such as polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), or tetrafluoroethylene-ethylene copolymer (ETFE), and/or a hydrophilic resin film formed from, for example, polyvinylpyrrolidone, polyethylene glycol, or methyl vinyl ether maleic anhydride copolymer.

As mentioned above, the X-ray transparent portion 33 is located within a range of 10 mm (see L1 in Figure 1) from the leading end 30a of the pressing portion 30 (the leading end including the cover 39), and the axial length L2 of the X-ray transparent portion 33 is set to 1 to 5 mm.

(Modification)
The shapes and structures of the core wire, the pressing portion, the coil portion and the X-ray transparent portion that constitute the pressing portion, etc. in the above-described embodiment are not limited to the above-described embodiments.

For example, the core wire may be formed from wire with a rectangular cross section, or the tip of the core wire may be shaped to consist of only one or more tapered sections that gradually decrease in diameter toward the axial tip (a shape with no straight sections), or may be shaped to consist of one or more straight sections of a constant outer diameter that are smaller than the base section and are connected in the axial direction (a shape with no tapered sections).

The pressing portion may have an X-ray opaque portion at its most distal end and an X-ray transparent portion at a position adjacent to the axial base end (this will be described in the fourth embodiment below). Furthermore, the coil portion constituting the pressing portion may be formed from an X-ray transparent material such as stainless steel. While the X-ray transparent portion 33 in this embodiment is a loosely wound coil that can expand and contract, it may also be a tightly wound coil or a member that does not flex (this will be described in the second and third embodiments below). While the pressing portion 30 in this embodiment has a cover 39, this cover 39 need not be present.

Furthermore, in this embodiment, the outer diameters of the coil portion 31 and the X-ray transparent portion 33 and the wire diameters of the wires 31a, 33a forming them are the same, but, for example, the outer diameter and wire diameter of the X-ray transparent portion 33 may be larger or smaller than the outer diameter and wire diameter of the coil portion 31. Also, the gap P2 between adjacent wires 33a, 33a in the X-ray transparent portion 33 may be smaller than the gap P1 between adjacent wires 31a, 31a in the coil portion 31, or may be the same.

Furthermore, in this embodiment, there is one coil portion 31 and one X-ray transparent portion 33, but there may be multiple coil portions and multiple X-ray opaque portions (this will be explained in the fourth embodiment below). However, even in this case, at least one X-ray transparent portion must be located within a range of 10 mm from the tip of the pressing portion.

In addition, in this embodiment, the radially inner side of the coil portion 31 and the X-ray transparent portion 33 is filled with a filler material 37 made of adhesive or the like, but the inside of the coil portion or the X-ray transparent portion may be left empty without being filled with a filler material.

(Action and effect)
Next, the effects of the pusher 10 according to the present invention having the above-described configuration will be described.

That is, under X-ray fluoroscopy (radiofluorography), a contrast agent is administered into the body using the well-known Seldinger technique or the like, while the catheter 5 is guided and moved via a guidewire (not shown) until its tip reaches a predetermined position. The guidewire is then removed from the catheter 5, the occlusion coil 1 is housed inside the catheter 5, and the pusher 10 is inserted from the proximal end 5b of the catheter 5, as shown by the arrow in Figure 2. The pushing portion 30 of the pusher 10 then presses the occlusion coil 1, moving it within the catheter 5. Finally, the occlusion coil 1 is pushed out from the distal end 5a of the catheter 5, placing the occlusion coil 1 in the affected area A. When the affected area A is an aneurysm or the like, as in this embodiment, multiple occlusion coils 1 are often placed in the affected area A, as shown in Figure 4.

In this pusher 10, the pressing portion 30 has at least one coil portion 31 formed by winding a wire 31a, and an X-ray transparent portion 33 with an axial length L2 of 1 to 5 mm, located within a range of 10 mm from the tip 30a of the pressing portion 30 (see L1 in Figure 1), and the portion adjacent to the X-ray transparent portion 33 forms an X-ray opaque portion.

This makes it easier to visualize the boundary between the base end 1a of the occlusion coil 1 and the distal end 30a of the pressing portion 30 under X-ray fluoroscopy.

in particular,
(1) As shown in the X-ray fluoroscopic image G1 in FIG. 3, the occlusive coil 1 made of a radiopaque material is visually recognized under X-ray fluoroscopy as being darker in color than the X-ray transparent portion 33 (here, it is visually recognized as black).
(2) As shown in the X-ray fluoroscopic image G2 in FIG. 3, the X-ray transparent portion 33, which is provided within a range of 10 mm from the tip 30a of the pressing portion 30 (see L1 in FIG. 1) and is made of an X-ray transparent material and has an axial length L2 of 1 to 5 mm, is visually recognized under X-ray fluoroscopy as being brighter in color than the occlusive coil 1 and the X-ray opaque portion (coil portion 31) (here, it is visually recognized as being white).
(3) As shown in the X-ray fluoroscopic image G3 in Figure 3, the X-ray opaque portion (coil portion 31) made of an X-ray opaque material adjacent to the X-ray transparent portion 33 appears darker than the X-ray transparent portion 33 under X-ray fluoroscopy (here, it appears as a color slightly lighter (pale) than the occlusion coil 1, closer to black).

In other words, under X-ray fluoroscopy, from left to right in Figure 3, a black X-ray fluoroscopy image G1 due to the occlusive coil 1, a white X-ray fluoroscopy image G2 due to the X-ray transparent portion 33, and an X-ray fluoroscopy image G3 due to the coil portion 31, which is X-ray transparent and is slightly brighter and closer to black than the occlusive coil 1, can be seen arranged in parallel along the axial direction of the occlusive coil 1 and the pusher 10.

As a result, a large contrast between black or near-black and white or near-white appears at the boundary between the proximal end 1a of the occlusive coil 1 (see FIG. 2) and the distal end 30a of the pressing portion 30 (see FIG. 3). This makes the boundary between the proximal end 1a of the occlusive coil 1 and the distal end 30a of the pressing portion 30 more visible. Furthermore, in this embodiment, a coil portion 31 made of an X-ray opaque material is positioned adjacent to the X-ray transparent portion 33 located at the distal end 30a of the pressing portion 30. Therefore, an X-ray fluoroscopic image G2 that is brighter or near-white than the X-ray fluoroscopic images G1, G2 is positioned between the X-ray fluoroscopic image G1 of the occlusive coil 1 and the X-ray fluoroscopic image G3 of the coil portion 31. This makes it appear as if a gap has appeared between the proximal end 1a of the occlusive coil 1 and the distal end 30a of the pressing portion 30 (see FIG. 3).

This makes it easier for the user of the pusher 10 to recognize the base end position (position closer to the hand) of the occlusive coil 1 and the tip position of the pressing portion 30 under X-ray fluoroscopy, allowing them to accurately grasp the pushing status when pushing the occlusive coil 1 out of the tip portion 5a of the catheter 5, preventing over-pushing of the occlusive coil 1 and resulting displacement of the occlusive coil 1 from its placement position, thereby improving the workability of the occlusive coil 1 placement procedure. Furthermore, by preventing over-pushing of the occlusive coil 1 by the pressing portion 30 of the pusher 10 and resulting displacement of the occlusive coil 1 from its placement position, the occlusive coil 1 can be placed accurately at the desired position within the body, and further, damage to internal organs, etc. caused by over-pushing of the occlusive coil 1 can be prevented.

In addition, the pressing portion 30 has at least one coil portion 31 formed by winding a wire 31a, ensuring flexibility at the tip of the pusher 10, which also improves the ease of placement of the occlusion coil 1.

Note that Figure 5(a) shows a comparative example of an occlusive coil pusher 100 (hereinafter simply referred to as "pusher 100"). The pressing portion 30 of this pusher 100 consists only of a coil portion made of an X-ray opaque material, and does not have an X-ray transparent portion 33 like the pusher 10 of the first embodiment. In this case, as shown in Figure 5(b), under X-ray fluoroscopy, the occlusive coil 1 and the entire pressing portion 30 are both visible as black or nearly black, and because the difference in brightness between the base end 1a of the occlusive coil 1 and the tip end 30a of the pressing portion 30 is small, the boundary between them is difficult to see.

As described above, in this pusher 10, the pressing portion 30 is located within a range of 10 mm from its tip 30a (see L1 in Figure 1), and has an X-ray transparent portion 33 with an axial length L2 of 1 to 5 mm, thereby achieving the above-mentioned effects. However, if the above conditions are not met, the following will occur.

In other words, if the axial length L2 of the X-ray transparent portion 33 is less than 1 mm, the X-ray transparent portion 33 will be difficult to see under X-ray fluoroscopy, making it difficult to recognize the proximal end position of the occlusion coil 1 and the distal end position of the pressing portion 30.

Furthermore, if the axial length L2 of the X-ray transparent portion 33 exceeds 5 mm, it becomes difficult to distinguish under X-ray fluoroscopy whether the bright color is due to the X-ray transparent portion 33 provided in the pressing portion 30 or due to the increased distance between the base end 1a of the occlusive coil 1 and the distal end 30a of the pressing portion 30, making it difficult to recognize the distal position of the pressing portion 30. As a result, there is a risk that the occlusive coil 1 will be pushed too far with the pusher 10, causing the placement position of the occlusive coil 1 to shift within the body. Furthermore, there is a risk that pushing the occlusive coil 1 too far may damage internal organs, etc.

Furthermore, if the X-ray transparent portion 33 is positioned more than 10 mm from the distal end 30a of the pressing portion 30, it becomes difficult to recognize the distal position of the pressing portion 30. Therefore, when the distal end 30a of the pressing portion 30 abuts against the proximal end 1a of the occlusive coil 1, it becomes difficult to recognize the boundary between the proximal end 1a of the occlusive coil 1 and the distal end 30a of the pressing portion 30, making it difficult to grasp how far the occlusive coil 1 has been pushed out from the distal end 5a of the catheter 5.

In addition, in this embodiment, as shown in Figure 1, the X-ray transparent portion 33 is located at the leading end 30a of the pressing portion 30.

In this embodiment, the X-ray transparent portion 33 is positioned axially adjacent to the base end 1a of the occlusive coil 1, making it easier to visualize the boundary between the base end 1a of the occlusive coil 1 and the distal end 30a of the pressing portion 30 under X-ray fluoroscopy.

Furthermore, in this embodiment, the coil portion 31 forms the radiopaque portion, and the X-ray transparent portion 33 is formed by winding wire 33a and has a coil shape. The gap P2 between adjacent wires 33a, 33a in the X-ray transparent portion 33 is larger than the gap P1 between adjacent wires 31a in the coil portion 31, which forms the radiopaque portion (see Figure 1).

According to the above aspect, the gap P2 between adjacent wires 33a, 33a in the X-ray transparent portion 33 is larger than the gap P1 between adjacent wires 33a, 33a in the X-ray opaque portion, which makes it easier for X-rays to pass through the X-ray transparent portion 33, making it easier to see the boundary between the base end 1 of the occlusive coil 1, which is made of an X-ray opaque material, and the tip 30a of the pressing portion 30 under X-ray fluoroscopy (the X-ray transparent portion 33 appears whiter under X-ray fluoroscopy, which increases the contrast between the X-ray transparent portion 33 and the occlusive coil 1, making it easier to see the boundary between the base end 1 of the occlusive coil 1 and the tip 30a of the pressing portion 30). Furthermore, because the X-ray transparent portion 33 in this embodiment is coil-shaped, flexibility is ensured at the tip of the pusher 10, and the conventional operating feel is maintained, while improving the visibility of the boundary between the base end 1a of the occlusion coil 1 and the distal end 30a of the pressing portion 30 under X-ray fluoroscopy.

(Second embodiment of the pusher for the occlusion coil)
6(a) shows a second embodiment of the occlusion coil pusher according to the present invention. Note that parts that are essentially the same as those in the previous embodiment are given the same reference numerals and their description will be omitted.

The pusher 10A for occlusion coils of this second embodiment (hereinafter also referred to simply as "pusher 10A") differs from the first embodiment in the structure of the pressing portion 30A.

In other words, the X-ray transparent portion 33A of this pressing portion 30A is not coiled like the X-ray transparent portion 33 of the first embodiment, and is a member that does not flexibly deform. Furthermore, this X-ray transparent portion 33A that does not flexibly deform is located at the leading end 30a of the pressing portion 30A. Alternatively, an X-ray opaque portion that does not flexibly deform may be located at the leading end 30a of the pressing portion 30A.

In this embodiment, the X-ray transparent portion 33A or the X-ray opaque portion located at the leading end 30a of the pressing portion 30 is made of a material that does not flex or deform, allowing for improved hardness and rigidity compared to the coil itself, thereby improving the pushing function of the occlusion coil 1.

(Third embodiment of the occlusion coil pusher)
6(b) shows a third embodiment of the pusher for an occlusion coil according to the present invention. Note that parts that are substantially the same as those in the previous embodiment are given the same reference numerals and their description will be omitted.

The third embodiment of the occlusion coil pusher 10B (hereinafter simply referred to as "pusher 10B") differs from the first and second embodiments in the structure of the pressing portion 30B.

In other words, the X-ray transparent portion 33B of this pressing portion 30B is a member that does not flexibly deform, similar to the X-ray transparent portion 33A of the second embodiment, and the X-ray transparent portion 33B is connected to the tip of the second tapered portion 26 of the tip portion 23 of the core wire 20 and is formed integrally with the core wire 20. That is, the X-ray transparent portion 33B in this embodiment is part of both the pressing portion 30B and the core wire 20. Furthermore, the X-ray transparent portion 33B has a larger diameter than the outer diameter of the second tapered portion 26 of the tip portion 23 of the core wire 20, and its tip surface 34 is flat, while its base end surface 36 is an inversely tapered surface that gradually protrudes less toward the base portion 21 of the core wire 20.

In this embodiment, as in the second embodiment, the X-ray transparent portion 33B located at the leading end 30a of the pressing portion 30B is made of a material that does not flex or deform, thereby improving the pushing function of the occlusive coil 1.

(Fourth embodiment of the pusher for the occlusion coil)
A fourth embodiment of the pusher for an occlusion coil according to the present invention is shown in Figure 7. Note that parts that are essentially the same as those in the previous embodiment are given the same reference numerals and their description will be omitted.

The fourth embodiment of the occlusion coil pusher 10C (hereinafter simply referred to as "pusher 10C") differs from the first to third embodiments in the structure of the pressing portion 30C.

That is, in this embodiment, the pressing portion 30C has multiple X-ray transparent portions 33C arranged in the axial direction of the core wire 20, with at least one of them being located within 10 mm of the distal end 30a of the pressing portion 30C (see L1 in FIG. 7), and another X-ray transparent portion 33C being located proximally, i.e., 10 mm closer to the proximal end 30a of the pressing portion 30C (see FIG. 7(a)). Furthermore, the coil portion 31C forms an X-ray opaque portion, which is located at the distal end 30a of the pressing portion 30C and is configured to appear fainter than the occlusion coil 1 under X-ray fluoroscopy (see X-ray fluoroscopic image G3 in FIG. 7(b)).

More specifically, this pressing portion 30C has three coil portions 31C (forming X-ray opaque portions) arranged from the tip 27a of the second linear portion 27 of the core wire 20 toward the base 21, and X-ray transparent portions 33C arranged between the coil portions 31C (see FIG. 7(a)). In other words, from the very tip of the core wire 20 toward the base 21, with the coil portion 31C at the head, multiple X-ray transparent portions 33C and coil portions 31C are arranged alternately (three coil portions 31C and two X-ray transparent portions 33C are arranged).

Also, as shown in Figure 7(b), under X-ray fluoroscopy, from left to right in the figure (from the tip side of the core wire 20 to the base 21 side), there are a black X-ray fluoroscopy image G1 due to the occlusive coil 1, an X-ray fluoroscopy image G3 due to the coil portion 31C, which is an X-ray opaque portion and is slightly brighter and closer to black than the occlusive coil 1, and a white X-ray fluoroscopy image G2 due to the X-ray transparent portion 33C. Following this, X-ray fluoroscopy images of different brightness, G3 and G2, can be viewed alternately along the axial direction of the pusher 10C.

In this embodiment, the radiopaque portion (coil portion 31C) is located at the distal end 30a of the pressing portion 30 and is configured to be visible under X-ray fluoroscopy as a lighter color than the occlusive coil 1. Therefore, even when the radiopaque portion is located at the distal end 30a of the pressing portion 30C, the boundary between the proximal end 1a of the occlusive coil 1 and the distal end 30a of the pressing portion 30C is easily visible under X-ray fluoroscopy, making it easier to recognize the proximal end position of the occlusive coil 1 and the distal end position of the pressing portion 30C. As a result, over-pressing the occlusive coil 1 and misalignment of the occlusive coil 1 are suppressed, improving the ease of placement of the occlusive coil 1.

Furthermore, in this embodiment, multiple X-ray transparent portions 33C are arranged in the axial direction of the core wire 20, with at least one of them located within 10 mm of the distal end 30a of the pressing portion 30C (see L1 in Figure 7), and other X-ray transparent portions 33C located proximally. Therefore, even if, for example, multiple occlusion coils 1 are placed at a predetermined location in the body (here, affected area A, such as an aneurysm) and the pressing portion 30C is buried among the occlusion coils 1, making the X-ray transparent portion 33C at the distal end of the pressing portion 30C difficult to visualize under X-ray fluoroscopy, the position of the pressing portion 30C can be estimated using the X-ray transparent portion 33C at the proximal end. Furthermore, because the pressing portion 30C has multiple X-ray transparent portions 33, it is easy to determine the direction of travel of the pusher 10C.

The present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the present invention, and such embodiments are also included in the scope of the present invention.

1 Occlusion coil 5 Catheter 10, 10A, 10B, 10C Occlusion coil pusher (pusher)
20 Core wire 21 Base portion 23 Tip portion 30, 30A, 30B, 30C Pressing portion 30a Foremost end 31 Coil portion 33, 33A, 33B, 33C X-ray transparent portion

Claims (4)

An occlusion coil pusher for pushing out an occlusion coil made of a radiopaque material disposed in a catheter, comprising:
a core wire having a base portion and a tip portion whose diameter is smaller than that of the base portion;
a pressing portion provided at a tip end of the core wire and configured to press the occlusive coil,
the pressing portion has at least one coil portion formed by winding a wire rod, and an X-ray transparent portion that is provided within a range of 10 mm from the tip of the pressing portion and has an axial length of 1 to 5 mm, and a portion adjacent to the X-ray transparent portion forms an X-ray opaque portion;
The pusher for an occlusive coil is characterized in that the radiopaque portion is located at the tip of the pressing portion and is configured to be visible under X-ray fluoroscopy in a fainter light than the occlusive coil. the coil portion forms the radiopaque portion, and the radiolucent portion forms a coil shape formed by winding a wire,
2. The occlusive coil pusher according to claim 1 , wherein the gaps between adjacent wire rods in the X-ray transparent portion are larger than the gaps between adjacent wire rods in the X-ray opaque portion. The radiopaque portion is a member that does not bend or deform,
2. The occlusion coil pusher according to claim 1, wherein the non-flexible member is disposed at the tip of the pressing portion. a plurality of the X-ray transparent portions are arranged in the axial direction of the core wire;
At least one of them is disposed within a range of 10 mm from the tip of the pressing portion,
4. The pusher for an occlusion coil according to claim 1 , wherein another X-ray transparent portion is disposed on the base side of the pusher.