JP6929020B2 - catheter - Google Patents

Description

The present invention relates to a catheter including a reinforcing member.

The properties required for a catheter inserted into a blood vessel are pushability, torque transmission, followability, and kink resistance. Pushability is required to appropriately transmit the force in the extension direction applied to the proximal end side of the catheter to the distal end side when the catheter is moved forward to the target site in the blood vessel. Torque transmission is required to properly transmit the rotational force applied to the proximal end side of the catheter to the distal end side. Followability is required for the smooth progress of the catheter within the flexed vessel. Kink resistance is required to prevent the catheter from bending at the flexion of the blood vessel and causing the lumen to collapse.

Various proposals have been made to satisfy the above characteristics in catheters. For example, Patent Document 1 proposes a medical device having a hollow body shaft (hereinafter, also referred to as “reinforcing member”) in which a wire is spirally wound. Further, Patent Document 2 proposes a balloon catheter in which a reinforcing member made of a network of metal wires is fixed to an inner tube.

Japanese Unexamined Patent Publication No. 2005-296078 Japanese Unexamined Patent Publication No. 10-57495

In the case of a catheter having a coiled reinforcing member as in Patent Document 1, the indentability and torque transmission may not satisfy the required level. On the other hand, in the case of a catheter having a reticulated body reinforcing member as in Patent Document 2, the followability and kink resistance may not satisfy the required level. Therefore, it is desired to realize a catheter having excellent all characteristics.

An object of the present invention is to provide a catheter having a reinforcing member having excellent pushability, torque transmission, followability, and kink resistance.

The catheter according to the first aspect of the present invention is a reinforcing member that extends from the proximal end to the distal end along the extending direction to reinforce the catheter, and is a tubular member in which a wire is wound in a coil shape. A coiled portion in which the lumen extends from the tip end to the proximal end side along the extending direction, and a tubular member in which a wire is woven in a net shape, and the lumen is the proximal end along the extending direction. A catheter including a reinforcing member having a mesh portion extending from the to the tip end side and a tubular tubular member covering the reinforcing member, and the end of the coiled portion of the reinforcing member on the proximal end side. By joining the coil-shaped base end which is The portion overlapping the shape portion has a plurality of first hardness same regions having substantially the same hardness in the stretching direction, and the same diameter region having substantially the same outer diameter in the stretching direction. The hardness of each of the plurality of the first hardness same regions is different, and the hardness of each of the plurality of the first hardness same regions becomes softer toward the tip side, and a plurality of the first hardness regions are present. wherein any of径同one region includes at least a portion of each of at least two of said first hardness same region, in the stretching direction, the position of the boundary between a plurality of said stiffness same region, a plurality of the It is characterized in that it differs from the position of the boundary between regions having the same diameter.

In the above reinforcing member, the net-like portion provided on the proximal end side in the stretching direction is excellent in pushability and torque transmission. Therefore, since the reinforcing member can appropriately transmit the force applied to the proximal end side in the stretching direction to the distal end side, the reinforcing member can appropriately move forward to the target portion in the blood vessel. Further, the reinforcing member can appropriately transmit the rotational force applied to the proximal end side to the distal end side. On the other hand, the coiled portion provided on the tip side in the stretching direction is excellent in followability and kink resistance. Therefore, the reinforcing member can smoothly proceed along the blood vessel when moving forward to the target site in the bent blood vessel. In addition, the reinforcing member can prevent the lumen from being crushed by bending at a bent portion in the vicinity of the target portion of the blood vessel. Further, the coiled base end of the coiled portion and the reticulated tip of the reticulated portion are joined. Therefore, the reinforcing member can have both the pushability and torque transmission property of the mesh portion and the followability and kink resistance of the coiled portion. Therefore, the reinforcing member can realize excellent characteristics in pushability, torque transmission, followability, and kink resistance.
Further, in order for the catheter to move smoothly in the blood vessel, it is preferable that the outer diameter of the catheter is uniform. Further, in a catheter, the hardness of the tip portion, which is often inserted into a bent blood vessel, is preferably small, and the hardness of the proximal portion to which a force when pushing the catheter into the blood vessel from outside the body is directly applied. Is preferably larger. On the other hand, the catheter has a portion having a different hardness in a region having the same diameter and having substantially the same outer diameter. Therefore, the hardness on the tip side can be made smaller and the hardness on the base end side can be made larger while the outer diameters are substantially the same. Therefore, the catheter can realize the characteristics of excellent followability at the distal end portion and pushability at the proximal end portion.
The catheter according to the second aspect of the present invention is a reinforcing member extending from the proximal end to the distal end along the extending direction to reinforce the catheter, and is a tubular member in which a wire is wound in a coil shape. A coiled portion in which the lumen extends from the tip end to the proximal end side along the extending direction, and a tubular member in which a wire is woven in a net shape, and the lumen is the proximal end along the extending direction. A catheter including a reinforcing member having a net-like portion extending from the reinforcing member to the distal end side and a tubular tubular member covering the reinforcing member, and the end of the coiled portion of the reinforcing member on the proximal end side. By joining the coiled base end which is The portion overlapping the shape portion has a plurality of first hardness same regions having substantially the same hardness in the stretching direction, and has a diameter changing region in which the outer diameter changes in the stretching direction. The hardness of each of the plurality of the first hardness same regions is different, and the hardness of each of the plurality of the first hardness same regions becomes softer toward the tip side, and the diameter change region becomes , A portion of the tubular member that is included in any of the plurality of first hardness same regions, the hardness of the tubular member does not change in the diameter change region, and overlaps with the reticulated portion in the stretching direction. The hardness does not change in the stretching direction, the outer diameter does not change in the stretching direction, and the position of the boundary between the plurality of the same hardness regions in the stretching direction is the diameter changing region. It is characterized by being different from the position.

In the first aspect and the second aspect, a joint portion for joining the coiled base end and the net-like tip may be provided. In this case, the coil-shaped base end and the net-like tip can be firmly joined by the joining portion.

In the first and second aspects, the joint has a fastening portion that covers the coiled base end and the reticulated tip from the radial outside of the respective lumens of the coiled portion and the reticulated portion. You may. In this case, the reinforcing member can appropriately join the coiled portion and the meshed portion.

In the first aspect and the second aspect, the material of the fastening portion may be a radiation opaque member. In this case, the reinforcing member can use the joint portion as an X-ray opaque marker. Therefore, the user can confirm the joint portion between the coil-shaped portion and the net-like portion by the joint portion under fluoroscopy.

In the first aspect and the second aspect, the coiled base end may be located closer to the base end side in the stretching direction than the net-like tip. In this case, each part of the coiled portion and the reticulated portion overlaps in the stretching direction. Therefore, the reinforcing member can join the coil-shaped portion and the net-shaped portion at a portion overlapping each other.

In the first aspect and the second aspect, the coil pitch of the coil tip region including at least the coiled tip which is the tip end side of the coiled portion gradually increases from the base end side toward the coiled tip. You may. In the reinforcing member, the tip may be inserted into a blood vessel having a large degree of bending. On the other hand, the reinforcing member can soften the coil tip region of the coiled portion as much as the tip. That is, since the followability at the tip is particularly excellent, the reinforcing member can insert the tip even into a blood vessel having a large degree of bending.

In the first aspect and the second aspect, the portion having the same second hardness region in which the hardness is substantially the same in the stretching direction and where the coiled base end and the net-like tip are joined is the first aspect. 2 Hardness may be included in the same region. In a catheter, the curvature when bent in response to an external force is applied varies with hardness. Therefore, the curvature also changes abruptly at the portion where the hardness in the stretching direction changes abruptly. In the catheter, it is preferable that the change in curvature when bent is small, so that the change in hardness in the stretching direction of the catheter is preferably small. On the other hand, in the catheter, the portion where the coiled portion and the reticulated portion are joined in the reinforcing member is included in the second hardness same region in which the hardness is substantially the same in the tubular member. In this case, the difference in hardness between the coiled portion and the meshed portion of the reinforcing member can be alleviated by the tubular member. Therefore, in the catheter, the change in hardness in the stretching direction at the portion where the coiled base end and the net-like tip are joined in the reinforcing member can be reduced, so that the curvature when the catheter is bent can be made substantially constant.

In the first aspect and the second aspect, the tubular member is a plurality of regions extending in the stretching direction, the first region arranged on the distal end side of the tubular member, and the proximal end side of the tubular member. It has a second region arranged and a third region sandwiched between the first region and the second region, and the hardness of the first region is the first hardness, and the second region. The hardness of the region is a second hardness larger than the first hardness, and the hardness of the third region is from the first hardness toward the second region side. It may change up to the second hardness. In this case, the hardness of the catheter can be relatively reduced by setting the distal end side as the first region, and relatively large by setting the proximal end side as the second region. Therefore, the catheter can realize the characteristics of excellent followability at the distal end portion and pushability at the proximal end portion. Further, the catheter can moderate the change in hardness by changing from the first hardness to the second hardness in the third region. Therefore, it is possible to suppress the change in curvature when the catheter is bent.
In the first aspect and the second aspect, the coil pitch of the coil base end region including at least the coil base end of the coil shape portion may gradually decrease from the tip end side toward the coil base end. In the reinforcing member, the curvature when bent in response to the application of an external force changes according to the hardness. Therefore, the curvature also changes abruptly at the portion where the hardness changes abruptly in the stretching direction. In the reinforcing member, it is preferable that the change in curvature when bent is small, so that the change in hardness in the stretching direction of the reinforcing member is preferably small. Usually, the hardness of the coiled portion is often smaller than the hardness of the reticulated portion. On the other hand, in the catheter, the coil base end region of the coiled portion can be made as hard as the coil base end by gradually reducing the coil pitch of the coil base end region of the reinforcing member from the tip end side toward the coil base end. .. As a result, the reinforcing member can reduce the change in hardness in the stretching direction at the joint portion where the coil-shaped portion and the net-like portion are joined. Therefore, the curvature when the reinforcing member is bent can be made substantially constant.

It is a side view of the catheter 1. FIG. It is a cross-sectional view which expanded the part of the frame line W1 of FIG. It is a cross-sectional view which expanded the part of the frame line W2 of FIG. It is a side view which enlarged the vicinity of the frame line W2 in the reinforcing member 2. It is sectional drawing which saw the AA line of FIG. 2 from the direction of an arrow. It is sectional drawing which saw the line BB of FIG. 2 from the direction of an arrow. It is sectional drawing which saw the CC line of FIG. 1 from the direction of an arrow. It is sectional drawing which saw the DD line of FIG. 1 from the direction of an arrow. It is sectional drawing which saw the EE line of FIG. 1 from the direction of an arrow.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The catheter 1 is a microcatheter used for applications such as embolization. As shown in FIG. 1, the catheter 1 has a reinforcing member 2 and a tubular member 5. Hereinafter, the end corresponding to one side of both ends of the catheter 1 is referred to as a "tip". The end corresponding to the other side of both ends of the catheter 1 is referred to as a "base end". The connector 9 for passing a wire or the like through the catheter 1 is connected to the proximal end of the catheter 1. The direction extending along the catheter 1 is referred to as "extending direction". On a plane orthogonal to the extension direction, in the radial direction with respect to the cross-sectional center of the catheter 1, the side close to the cross-sectional center of the catheter 1 is referred to as "inside", and the side separated from the cross-sectional center of the catheter 1 is "inside". It is called "outside".

<Reinforcing member 2>
The reinforcing member 2 is a flexible tubular member. The reinforcing member 2 has a function of reinforcing the strength of the catheter 1 in the extending direction. The length L2 of the reinforcing member 2 in the stretching direction is approximately 1615 mm. The reinforcing member 2 extends from the base end to the tip along the stretching direction. The reinforcing member 2 includes a coil-shaped portion 3, (see FIGS. 2, 3, and 4), a net-like portion 4 (see FIGS. 3 and 4), and a fastening portion 6 (see FIG. 2) and 7 (see FIG. 2). ), 8 (see FIGS. 3 and 4).

<Coil-shaped part 3>
As shown in FIG. 4, the coiled portion 3 is formed by winding a wire in a coil shape along the outer peripheral surface of the tubular inner layer portion 21. The diameter of the wire forming the coiled portion 3 is approximately 0.025 mm, and the material is SUS (stainless steel). As shown in FIGS. 5 to 9, the inner diameter R2 of the inner layer portion 21 is approximately 0.42 mm, and the thickness is approximately 0.02 mm. The material of the inner layer portion 21 is PTFE (polytetrafluoroethylene). As shown in FIG. 2, the lumen 3A of the coiled portion 3 is formed inside the inner layer portion 21. The radial medial and lateral sides of lumen 3A coincide with the medial and lateral sides of catheter 1, respectively. The inner diameter of the lumen 3A is substantially the same as the inner diameter R2 of the inner layer portion 21, and is approximately 0.42 mm. Lumen 3A extends from the distal end of the catheter 1 toward the proximal end. As shown in FIG. 1, the length L3 of the coiled portion 3 in the stretching direction is approximately 300 mm.

As shown in FIG. 2, a coil that includes an end on the tip side of the coil-shaped portion 3 (hereinafter, referred to as “coil-shaped tip 3P”) and extends from the coil-shaped tip 3P toward the base end side in the extending direction. The predetermined region of the shape portion 3 is referred to as "coil tip region 31". The length L31 (see FIG. 1) of the coil tip region 31 in the stretching direction is approximately 150 mm. As shown in FIG. 3, the coil-shaped portion 3 includes an end on the base end side (hereinafter, referred to as “coil-shaped base end 3B”) and extends from the coil-shaped base end 3B toward the tip end side in the extending direction. A predetermined region of the coil-shaped portion 3 is referred to as a "coil base end region 32". The length L32 (see FIG. 1) of the coil base end region 32 in the stretching direction is approximately 150 mm. The position of the end portion of the coil tip region 31 on the proximal end side coincides with the position of the distal end portion of the coil proximal region 32.

The coil pitch of the coil tip region 31 (see FIG. 2) gradually increases from approximately 0.1 mm from the proximal end side toward the coiled tip 3P. The coil pitch at the coiled tip 3P is approximately 3 mm. The coil pitch of the coil base end region 32 (see FIG. 3) gradually decreases from about 0.1 mm from the tip end side toward the coil base end 3B. The coil pitch at the coiled base end 3B is approximately 0.05 m.

<Reticulated part 4>
As shown in FIG. 4, the net-like portion 4 is arranged on the proximal end side of the coil-shaped portion 3. The net-like portion 4 is formed by weaving strands in a net shape along the outer peripheral surface of the inner layer portion 21. The diameter of the wire forming the reticulated portion 4 is approximately 0.025 mm, and the material is SUS (stainless steel). The woven structure of the net-like portion 4 is a twill weave, and the pitch of the strands is approximately 1.2 mm. As shown in FIGS. 3 and 4, the end on the tip side of the net-like portion 4 (hereinafter, referred to as “net-like tip 4P”) is adjacent to the base end side of the coil-like base end 3B of the coil-like portion 3.

As shown in FIG. 3, the lumen 4A of the reticulated portion 4 is formed inside the inner layer portion 21. The radial medial and lateral sides of lumen 4A coincide with the medial and lateral sides of catheter 1, respectively. The inner diameter of the lumen 4A is substantially the same as the inner diameter R2 (see FIGS. 5 to 9) of the inner layer portion 21, and is approximately 0.42 mm. The lumen 4A extends from the proximal end of the catheter 1 toward the distal end. As shown in FIG. 1, the length L4 of the reticulated portion 4 in the stretching direction is approximately 1315 mm.

<Fastening parts 6, 7, 8>
As shown in FIG. 2, the fastening portion 6 is provided in a portion of the coil tip region 31 of the coil-shaped portion 3 including the coil-shaped tip 3P. The fastening portion 6 is a cylindrical member. The center of the fastening portion 6 extends in the stretching direction. The length L6 of the fastening portion 6 in the stretching direction is approximately 0.6 mm. As shown in FIG. 6, the inner diameter of the fastening portion 6 is slightly larger than the inner diameter of the lumen 3A of the coiled portion 3. The thickness of the fastening portion 6 is approximately 0.03 mm. The fastening portion 6 covers the coiled portion 3 from the outside. The fastening portion 6 is fixed to the coiled portion 3 by being crimped by applying pressure from the outside to the inside of the catheter 1.

As shown in FIG. 2, the fastening portion 7 is provided at a position separated from the end of the fastening portion 6 on the proximal end side toward the proximal end side. The shape of the fastening portion 7 is the same as that of the fastening portion 6. The length L7 of the fastening portion 7 in the stretching direction is approximately 0.6 mm. The center of the fastening portion 7 extends in the stretching direction. As shown in FIG. 6, the fastening portion 7 covers the coiled portion 3 from the outside. The fastening portion 7 is fixed to the coiled portion 3 by being crimped by applying pressure from the outside to the inside of the catheter 1. As shown in FIG. 2, the length L67 in the stretching direction between the end on the distal end side of the fastening portion 6 and the end on the proximal end side of the fastening portion 7 is approximately 30 mm.

As shown in FIGS. 3 and 4, the fastening portion 8 is provided at a portion covering the coil-shaped base end 3B of the coil-shaped portion 3 and the net-like tip 4P of the net-like portion 4. The fastening portion 8 is a cylindrical member. The center of the fastening portion 8 extends in the stretching direction. The length L8 of the fastening portion 8 in the stretching direction is approximately 0.6 mm. The thickness of the fastening portion 8 is approximately 0.04 mm. The fastening portion 8 covers the vicinity of the coil-shaped base end 3B of the coil-shaped portion 3 and the vicinity of the net-like tip 4P of the net-like portion 4 from the outside. The fastening portion 8 joins the coiled base end 3B of the coiled portion 3 and the reticulated tip 4P of the reticulated portion 4 by crimping the catheter 1 by applying pressure from the outside to the inside. As a result, the lumen 3A of the coiled portion 3 and the lumen 4A of the reticulated portion 4 communicate with each other. The boundary portion between the coiled base end 3B of the coiled portion 3 and the meshed tip 4P of the meshed portion 4 is arranged substantially at the center of the fastening portion 8 in the extending direction.

The material of the fastening portions 6, 7 and 8 is a well-known radiation opaque member (for example, Pt (platinum)) that does not transmit radiation.

<Tubular member 5>
As shown in FIGS. 2 and 3, the tubular member 5 is a tubular member provided along the outer peripheral surface of the inner layer portion 21. The tubular member 5 covers the reinforcing member 2 from the outside over the entire area in the stretching direction. The material of the tubular member 5 is a blended material of nylon 12 and nylon elastomer. The lumen 5A of the tubular member 5 is formed inside the inner layer portion 21. The radial medial and lateral sides of lumen 5A coincide with the medial and lateral sides of catheter 1, respectively. The inner diameter of the lumen 5A is substantially the same as the inner diameter R2 (see FIGS. 5 to 9) of the inner layer portion 21, and is approximately 0.42 mm. Lumen 5A extends from the tip of the catheter 1 over the entire proximal end. As shown in FIG. 1, the length L5 of the tubular member 5 in the stretching direction is substantially the same as the length L2 of the reinforcing member 2 in the stretching direction, and is approximately 1615 mm. As shown in FIG. 2, the end on the tip end side of the tubular member 5 (hereinafter, referred to as “tubular tip 5P”) is arranged on the tip end side of the coiled tip 3P of the coiled portion 3 of the reinforcing member 2. The corner of the tubular tip 5P is curved.

As shown in FIG. 1, the tubular member 5 can be divided into four regions according to the outer diameter. Hereinafter, the four regions classified according to the outer diameter are referred to as diameter regions 51, 52, 53, and 54, respectively. The radial regions 51 to 54 are arranged in order from the distal end side to the proximal end side along the stretching direction.

Hereinafter, the lengths of the radial regions 51, 52, 53, and 54 in the stretching direction are referred to as L51 (see FIG. 2), L52 (see FIG. 2), L53 (see FIG. 1), and L54 (see FIG. 1). In this case, the respective lengths are approximately 0.6 mm (L51), approximately 90 mm (L52), approximately 30 mm (L53), and approximately 1495 mm (L54).

The outer diameters of the diameter regions 51, 52, 53, and 54 are referred to as R51 (see FIG. 5), R52 (see FIG. 6), R53 (see FIG. 7), and R54 (see FIGS. 8 and 9). In this case, the outer diameters are approximately 0.58 mm (R51), approximately 0.67 mm (R52), approximately 0.67 mm to approximately 0.8 mm (R53), and approximately 0.8 mm (R54). The outer diameters R51, R52, and R54 in the diameter regions 51, 52, and 54 are substantially the same in the respective regions in the stretching direction. On the other hand, the outer diameter R53 in the diameter region 53 is approximately 0.67 mm at the distal end side end of the radial region 53 and approximately 0.8 mm at the proximal end side end of the radial region 53. The outer diameter R53 of the diameter region 53 gradually increases from the tip end side to the base end side.

As described above, the outer diameter of the tubular member 5 gradually increases from the diameter region 51 on the most distal end side to the diameter region 54 on the most proximal end side. The coiled base end 3B of the coiled portion 3 of the reinforcing member 2 (see FIG. 3), the meshed tip 4P of the meshed portion 4 (see FIG. 3), and the fastening portion 8 (see FIG. 3) have a radial region in the stretching direction. It is included in 54.

As shown in FIG. 1, the tubular member 5 can be divided into seven regions according to the hardness. Hereinafter, the seven regions classified according to hardness are referred to as hardness regions 501, 502, 503, 504, 505, 506, and 507, respectively. The hardness regions 501 to 507 are arranged in order from the distal end side to the proximal end side along the stretching direction.

Hereinafter, the lengths of the hardness regions 501, 502, 503, 504, 505, 506, and 507 in the stretching direction are referred to as L501, L502, L503, L504, L505, L506, and L507. In this case, the respective lengths are approximately 5 mm (L501), approximately 5 mm (L502), approximately 50 mm (L503), approximately 70 mm (L504), approximately 110 mm (L505), approximately 30 mm (L506), and approximately 1345 mm (L507). Is. The hardness of each of the hardness regions 501, 502, 503, 504, 505, 506, and 507 is approximately 30D (hardness region 501), approximately 43D (hardness region 502), and approximately 48D (hardness region 503). Approximately 52D (hardness region 504), approximately 63D (hardness region 505), approximately 68D (hardness region 506), and approximately 74D (hardness region 507). The hardness of each of the hardness regions 501 to 507 is substantially the same in each region over the stretching direction.

As described above, the hardness of the tubular member 5 gradually increases from the hardness region 501 on the most distal end side to the hardness region 507 on the most proximal end side. The coiled base end 3B of the coiled portion 3 of the reinforcing member 2 (see FIG. 3), the meshed tip 4P of the meshed portion 4 (see FIG. 3), and the fastening portion 8 (see FIG. 3) have hardness in the stretching direction. Included in region 507.

As shown in FIG. 2, the boundary portions of the hardness regions 501 and 502 having different hardnesses in the stretching direction and the hardness regions 502 and 503 in the diameter regions 52 having substantially the same outer diameter in the stretching direction. Boundary part is included. As shown in FIG. 1, the diameter region 52 includes the boundary portion of the hardness regions 503 and 504. Further, in the diameter region 54 in which the outer diameters are substantially the same in the stretching direction, the boundary portions of the hardness regions 504 and 505 having different hardnesses in the stretching direction, the boundary portions of the hardness regions 505 and 506, and the hardness. The boundary portion of the regions 506 and 507 is included.

In the tubular member 5, the hardness different from each other is realized as described above by adjusting the composition of the materials in the hardness regions 501 to 507. The hardness of the catheter 1 itself is affected by the hardness of the reinforcing member 2 as well as the hardness of the tubular member 5. However, since the hardness of the tubular member 5 is dominant over the hardness of the reinforcing member 2, the height of the catheter 1 is substantially the same as the hardness of the tubular member 5.

<How to use Catheter 1>
An example of how to use the catheter 1 will be described. First, the user shapes the tip of the catheter 1 as needed. The user is a doctor or the like. Next, the lumens 3A, 4A, and 5A of the catheter 1 are passed through the guide wire previously inserted into the blood vessel. The user applies a force to the proximal end side of the catheter 1 and pushes the catheter 1 into the blood vessel in order from the distal end side. The user moves the catheter 1 forward while confirming the positions and movements of the fastening portions 6 to 8 of the catheter 1 under fluoroscopy. The user also rotates the catheter 1 as needed to orient the tip of the catheter 1 in a desired direction. In this way, the user makes the tip of the catheter 1 reach the target site in the blood vessel.

The user then removes the guide wire from the catheter 1. In this state, the user injects a contrast medium from the connector 9 or inserts an embolic substance as needed.

<Main actions and effects of this embodiment>
In the catheter 1, the reticulated portion 4 provided on the proximal end side in the extending direction of the reinforcing member 2 is excellent in pushing property and torque transmission property. Therefore, the net-like portion 4 can appropriately transmit the force applied to the proximal end side in the stretching direction to the distal end side. Therefore, the user can appropriately move the catheter 1 forward to the target site in the blood vessel. Further, the net-like portion 4 can appropriately transmit the rotational force applied to the proximal end side to the distal end side. Therefore, even when the user rotates the proximal end side in order to direct the distal end of the catheter 1 in a desired direction, the distal end of the catheter 1 can be appropriately rotated.

On the other hand, of the reinforcing member 2, the coil-shaped portion 3 provided on the tip end side in the stretching direction is excellent in followability and kink resistance. Therefore, the coiled portion 3 can smoothly advance the catheter 1 along the blood vessel when the catheter 1 moves forward to the target site in the bent blood vessel. Further, the coiled portion 3 can prevent the lumen from being crushed by bending at a bent portion in the vicinity of the target portion of the blood vessel. In particular, the catheter 1 is often used by inserting the tip portion into a portion of the blood vessel where the degree of bending is large. In such a case, the coiled portion 3 arranged at the tip end portion of the catheter 1 functions effectively due to its excellent followability and kink resistance.

Further, in the reinforcing member 2, the coil-shaped portion 3 and the net-shaped portion 4 are joined by the fastening portion 8. Therefore, the reinforcing member 2 can have both the pushability and torque transmission property of the mesh portion 4 and the followability and kink resistance of the coiled portion 3. Therefore, the catheter 1 provided with the reinforcing member 2 can realize excellent characteristics in pushability, torque transmission, followability, and kink resistance.

The fastening portion 8 has a cylindrical shape and covers the vicinity of the coil-shaped base end 3B of the coil-shaped portion 3 and the vicinity of the net-like tip 4P of the net-like portion 4 from the outside. The fastening portion 8 joins the coiled portion 3 and the reticulated portion 4 by crimping the catheter 1 by applying pressure from the outside to the inside. Therefore, the fastening portion 8 has a coiled portion 3 and a meshed portion 4 as compared with a case where the coiled base end 3B of the coiled portion 3 and the meshed tip 4P of the meshed portion 4 are directly joined with an adhesive or the like. Can be joined properly. Further, by using the material of the fastening portion 8 as a radiation opaque member, the fastening portion 8 can be used as an X-ray opaque marker. Therefore, the user can move the catheter 1 forward in the blood vessel while confirming the joint portion between the coiled portion 3 and the reticulated portion 4 by the joint portion under fluoroscopy.

The catheter 1 is often used with the tip inserted into a blood vessel having a large degree of flexion. On the other hand, the coil pitch of the coil tip region 31 of the coil-shaped portion 3 gradually increases from about 0.1 mm from the proximal end side toward the coil-shaped tip 3P. As a result, the coil tip region 31 of the coil-shaped portion 3 can be made as soft as the coil-shaped tip 3P. That is, the catheter 1 has particularly excellent followability at the tip. Therefore, the catheter 1 can be inserted into the tip even in a blood vessel having a large degree of flexion.

In the catheter 1, the curvature when bent in response to the application of an external force changes according to the hardness. Therefore, the curvature also changes abruptly at the portion where the hardness changes abruptly in the stretching direction. In the catheter 1, it is preferable that the change in curvature when bent is small, so that the change in hardness in the stretching direction of the catheter 1 is preferably small. Here, usually, the hardness of the coil-shaped portion 3 is often smaller than the hardness of the mesh-shaped portion 4. On the other hand, the coil pitch of the coil base end region 32 gradually decreases from about 0.1 mm from the tip end side toward the coil base end 3B. As a result, the coil base end region 32 of the coil-shaped portion 3 can be made as hard as the coil base end 3B. Therefore, the reinforcing member 2 can reduce the change in hardness in the stretching direction at the boundary portion between the coil-shaped portion 3 and the mesh-shaped portion 4. Therefore, the catheter 1 can have a substantially constant curvature when bent.

In order for the catheter 1 to move smoothly in the blood vessel, it is preferable that the outer diameter of the catheter 1 is uniform. Further, in the catheter 1, the hardness of the distal end portion, which is often inserted into a bent blood vessel, is preferably small, and the hardness of the proximal end portion to which a force when pushing the catheter into the blood vessel from outside the body is directly applied is preferable. The larger the hardness, the better.

On the other hand, in the catheter 1, the outer diameters R52 and R54 in the diameter regions 52 and 54 of the tubular member 5 are substantially the same in the stretching direction, respectively. Further, the diameter region 52 includes a boundary portion of the hardness regions 501 and 502 having different hardnesses in the stretching direction, a boundary portion of the hardness regions 502 and 503, and a boundary portion of the hardness regions 503 and 504. Further, the diameter region 54 includes a boundary portion of the hardness regions 504 and 505 having different hardnesses in the stretching direction, a boundary portion of the hardness regions 505 and 506, and a boundary portion of the hardness regions 506 and 507. That is, a portion of the tubular member 5 having substantially the same outer diameter includes a portion having a different hardness. Therefore, the catheter 1 can be made to have substantially the same outer diameter, gradually reduce the hardness on the distal end side, and gradually increase the hardness on the proximal end side. Therefore, the catheter 1 can realize the characteristics of excellent followability at the distal end portion and pushability at the proximal end portion.

The coiled base end 3B of the coiled portion 3, the meshed tip 4P of the meshed portion 4, and the fastening portion 8 are included in the hardness region 507 in the stretching direction. The hardness of the hardness region 507 is substantially the same over the stretching direction. That is, the fastening portion 8 in which the coiled portion 3 and the meshed portion 4 are joined in the reinforcing member 2 is included in the hardness region 507 in which the hardness of the tubular member 5 is substantially the same. In this case, the difference in hardness between the coiled portion 3 and the meshed portion 4 of the reinforcing member 2 can be alleviated by the tubular member 5. Therefore, since the catheter 1 can reduce the change in hardness in the stretching direction at the joint portion between the coiled portion 3 and the reticulated portion 4, the curvature when the catheter 1 is bent can be made substantially constant.

<Modification example>
The present invention is not limited to the above embodiment, and various modifications can be made. The present invention is not limited to the dimensions, ratios, materials, etc. of each configuration shown above, and these can be changed as appropriate. In the above, the catheter 1 has a structure having a reinforcing member 2 and a tubular member 5. On the other hand, the catheter 1 may have only the reinforcing member 2. The reinforcing member 2 does not have to have the fastening portions 6 and 7.

The cross-sectional shape of the wire forming the coil-shaped portion 3 and the net-shaped portion 4 is not limited to a circular shape. For example, the wire may be flat. Further, the strands may be formed by weaving fine fibers having a circular cross-sectional shape. The coil-shaped portion 3 may have a plurality of coils stacked concentrically around an axis extending along the stretching direction. Further, the plurality of coils may be wound in the same direction, or may be wound in different directions. The weaving structure of the net-like portion 4 is not limited to twill weave, but may be plain weave. Further, the net-like portion 4 may be formed by a hexagonal wire mesh. The coiled base end 3B of the coiled portion 3 and the reticulated tip 4P of the reticulated portion 4 may be slightly separated in the stretching direction.

A part of the coiled portion 3 including the coiled base end 3B and a part of the meshed portion 4 including the netted tip 4P may overlap in the stretching direction. In this case, the coil-shaped base end 3B is located closer to the base end side in the stretching direction than the net-like tip 4P. Further, in this case, a part of the coiled portion 3 including the coiled base end 3B may be arranged outside or inside the part of the meshed portion 4 including the meshed tip 4P. May be placed in. Further, in this case, a part of the region including the coiled base end 3B of the coiled portion 3 and a part of the region including the meshed tip 4P of the meshed portion 4 may be woven together. Further, in this case, the coiled portion 3 and the reticulated portion 4 may be joined by an adhesive or laser welding at a portion overlapping with each other. When the overlapping portions are joined by an adhesive or the like, the fastening portion 8 may not be provided.

In the coiled portion 3 and the reticulated portion 4, the coiled base end 3B and the reticulated tip 4P may come into contact with each other. In this case, the coil-shaped base end 3B and the net-like tip 4P are arranged at the same position in the stretching direction. Further, in this case, the coiled base end 3B of the coiled portion 3 and the meshed tip 4P of the meshed portion 4 may be joined by adhesive or laser welding. When the coil-shaped base end 3B and the net-like tip 4P are joined by an adhesive or the like, the fastening portion 8 may not be provided.

The fastening portion 8 can be changed to a member having a different shape capable of joining the coil-shaped base end 3B of the coil-shaped portion 3 and the net-like tip 4P of the net-like portion 4. For example, the fastening portion 8 may be formed with a plurality of slits extending along the stretching direction, or may be formed with a plurality of holes. The fastening portion 8 may have a coil shape in which the wire is wound in a coil shape, or may have a tubular shape in which the wire is woven into a net shape. The material of the fastening portion 8 is not limited to the radiation opaque member, and may be another material (for example, SUS or the like).

The coil pitch in the coil tip region 31 of the coil-shaped portion 3 may be gradually smaller than approximately 0.1 mm from the proximal end side toward the coil-shaped tip 3P. The coil pitch of the coil base end region 32 may gradually increase from approximately 0.1 mm from the tip end side toward the coil base end 3B. The coil pitch of the coiled portion 3 may be substantially the same over the entire area in the stretching direction. The coil-shaped portion 3 may have a coil central region between the coil tip region 31 and the coil base end region 32, which has substantially the same coil pitch in the stretching direction and is approximately 0.1 mm.

The positions in the stretching direction may coincide with the respective boundaries of the diameter regions 51 to 54 and the respective boundaries of the four adjacent regions of the hardness regions 501 to 507. That is, in the tubular member 5 of the catheter 1, a region having substantially the same outer diameter and a region having substantially the same hardness may be arranged at the same position in the stretching direction, respectively. The hardness of the tubular member 5 may differ between the distal end side and the proximal end side with respect to the boundary position between the coiled portion 3 and the meshed portion 4 of the reinforcing member 2.

The hardness regions 501 to 507 had substantially the same hardness in the stretching direction. On the other hand, at least one of the hardness regions 501 to 507 may have a different hardness in the stretching direction. In this case, for example, the hardness in a specific hardness region may gradually change from the hardness of the hardness region adjacent to the distal end side to the hardness region adjacent to the proximal end side. Specifically, for example, the hardness region 504 gradually changes from the hardness of the hardness region 503 (approximately 48D) to the hardness of the hardness region 505 (approximately 63D) from the tip end side to the base end side. May be good. Further, for example, the hardness regions 504, 505, and 506 gradually change from the hardness of the hardness region 503 (approximately 48D) to the hardness of the hardness region 507 (approximately 74D) from the tip end side to the proximal end side. You may. As described above, the catheter 1 can moderate the change in hardness by gradually changing the hardness in a specific hardness region. Therefore, the change in curvature when the catheter 1 is bent can be suppressed.

<Others>
The fastening portion 8 is an example of the “joining portion” of the present invention.

1: Catheter 2: Reinforcing member 3: Coiled part 3A, 4A, 5A: Lumen 3B: Coiled base end 3P: Coiled tip 4: Reticulated part 4P: Reticulated tip 5: Tubular member 6, 7, 8: Fastened Part 31: Coil tip region 32: Coil base end region

Claims (10)

A reinforcing member that extends from the proximal end to the distal end along the stretching direction to reinforce the catheter.
A tubular member in which a wire is wound in a coil shape, and a coiled portion in which a lumen extends from the tip end side to the base end side along the stretching direction.
A reinforcing member which is a tubular member in which a wire is woven in a net shape and has a net-like portion whose lumen extends from the base end to the tip end side along the stretching direction.
A catheter including a tubular tubular member that covers the reinforcing member.
By joining the coiled base end, which is the end on the base end side of the coiled portion of the reinforcing member, and the net-like tip, which is the end on the tip side of the net-like portion, the respective lumens. Communicate,
The portion of the tubular member that overlaps the coiled portion in the stretching direction is
It has a plurality of first hardness same regions having substantially the same hardness in the stretching direction, and has a plurality of diameter same regions having substantially the same outer diameter in the stretching direction.
The hardness of each of the plurality of first hardness same regions is different, and the hardness of each of the plurality of first hardness same regions becomes softer toward the tip side.
Any of the plurality of same diameter regions comprises at least a portion of each of at least two of the first hardness identical regions.
A catheter characterized in that, in the stretching direction, the position of a boundary between a plurality of the same hardness regions is different from the position of a boundary between a plurality of the same diameter regions. A reinforcing member that extends from the proximal end to the distal end along the stretching direction to reinforce the catheter.
A tubular member in which a wire is wound in a coil shape, and a coiled portion in which a lumen extends from the tip end side to the base end side along the stretching direction.
A reinforcing member which is a tubular member in which a wire is woven in a net shape and has a net-like portion whose lumen extends from the base end to the tip end side along the stretching direction.
A catheter including a tubular tubular member that covers the reinforcing member.
By joining the coiled base end, which is the end on the base end side of the coiled portion of the reinforcing member, and the net-like tip, which is the end on the tip side of the net-like portion, the respective lumens. Communicate,
The portion of the tubular member that overlaps the coiled portion in the stretching direction is
It has a plurality of first hardness identical regions having substantially the same hardness in the stretching direction, and has a diameter changing region in which the outer diameter changes in the stretching direction.
The hardness of each of the plurality of first hardness same regions is different, and the hardness of each of the plurality of first hardness same regions becomes softer toward the tip side.
The diameter change region is included in any of a plurality of the first hardness same regions.
The hardness of the tubular member does not change in the diameter change region,
Of the tubular members, the portion that overlaps the reticulated portion in the stretching direction is
The hardness did not change in the stretching direction, and the outer diameter did not change in the stretching direction.
A catheter characterized in that, in the stretching direction, the position of a boundary between a plurality of the same hardness regions is different from the position of the diameter change region. The catheter according to claim 1 or 2, further comprising a joint portion for joining the coiled base end and the net-like tip. The joint
The catheter according to claim 3, further comprising a fastening portion that covers the coiled base end and the reticulated tip from the radial outside of the respective lumens of the coiled portion and the reticulated portion. The catheter according to claim 4, wherein the material of the fastening portion is a radiation opaque member. The catheter according to any one of claims 1 to 5, wherein the coiled base end is located closer to the base end side in the extending direction than the reticulated tip. According to claim 1, the coil pitch of the coil tip region including at least the coiled tip, which is the end of the coiled portion on the tip end side, gradually increases from the base end side toward the coiled tip. 6. The catheter according to any one of 6. The tubular member has a second hardness same region in which the hardness is substantially the same in the stretching direction.
The catheter according to any one of claims 1 to 7, wherein the portion where the coiled base end and the reticulated tip are joined is included in the second hardness same region. The tubular member is a plurality of regions extending in the stretching direction, and is a first region arranged on the distal end side of the tubular member, a second region arranged on the proximal end side of the tubular member, and It has a third region sandwiched between the first region and the second region, and has a third region.
The hardness of the first region is the first hardness.
The hardness of the second region is a second hardness larger than the first hardness.
According to any one of claims 1 to 8, the hardness of the third region changes from the first hardness to the second hardness from the first region side to the second region side. The catheter described. Any of claims 1 to 9, wherein the coil pitch of the coil base end region including at least the coil base end of the coil shape portion gradually decreases from the tip end side toward the coil base end. The catheter described in.

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