JP2018089108A - Stent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stent which can be easily accommodated in a recovering sheath as the contraction condition becomes uniform when recovering it into the recovering sheath.SOLUTION: Regarding the stent to dilate a lumen in a body, a catheter stent includes: a stent body 10 of a network structure having an elastic force for dilation in the radial direction; a hook part 30 provided at one end side of the stent body; and a connection part 50 formed between the hook part and the stent body, being curved, bent or folded so that the hook part can be separated from the stent body and will be arranged at or near the circumference of the stent body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a stent, and more particularly to a stent in which a stent placed in an affected area can be easily collected.

  As a stent having a recovery mechanism, it has an annular structure having a tubular wall portion constituted by an inner surface and an outer surface, and an open end portion facing each other, and a circular peripheral base portion and an acute angle from this base portion or A stent recovery member has been proposed that includes a shaping projection having a first and second spaced apart member extending vertically and connected by a vertex portion (Patent Document 1).

  Such a recovery member can move and recover the stent by contracting the first end of the stent and pulling the shaping protrusion of the stent recovery member to move the stent.

  Similarly, as a stent having a recovery mechanism, a first opening end, a second opening end, and a tubular body between them are provided, and a member for performing at least one of recovery and rearrangement is a first opening. When a force is applied to the elongated portion by interlooping a member for performing at least one of recovery and rearrangement along the outer periphery of the first opening, the elongated portion includes an elongated portion extending from the end. There has been proposed a device that contracts in the radial direction and whose first opening end is narrowed (Patent Document 2).

  Such stents can be retrieved by grasping or hooking the interloop.

  However, each of the above stents has a problem that it is difficult to grasp or hook because the shaping protrusions or interloops that are gripped or hooked at the time of recovery are attached to the outer peripheral portion of the stent. In addition, when drawing, a part of the modeling protrusion or interloop is provided on a part of the outer periphery of the stent, so that the contraction degree of the stent is not uniform when pulled, or the modeling protrusion or interloop is not the stent. There is a problem that it is difficult to be accommodated in the recovery sheath.

Special table 2008-528200 gazette Special table 2013-505108 gazette

  Therefore, the present invention has been made in view of the above problems, and can be easily hooked even in a lumen, and when retracted into the recovery sheath, the contraction degree becomes uniform and the recovery sheath is pulled in. The main purpose is to provide an easy-to-use stent.

  The present invention adopts the following means in order to achieve the above-mentioned object.

A stent for expanding a body lumen according to the present invention is as follows.
A network-structured stent body having elastic force that expands in the radial direction;
A hook portion provided on one end side of the stent body portion;
The hook portion is bent, bent or folded so as to be separated from the stent main body portion between the hook portion and the stent main body portion, and the hook portion is at or near the outer periphery of the stent main body portion. A connecting portion formed to be disposed;
It is characterized by having.

  In the stent according to the present invention, the connecting portion that connects the hook portion and the stent main body portion is formed by bending, bending or folding, and the hook portion is disposed at or near the outer periphery of the stent main body portion. Therefore, the hook portion can be disposed on the inner wall of the lumen or in the vicinity of the inner wall, regardless of whether the lumen is a straight lumen or a curved lumen when the lumen is disposed in the lumen. Therefore, it is possible to prevent as much as possible from interfering with treatment or obstructing blood flow. In addition, the hook portion is disposed in the vicinity of the stent body portion when no force is applied, but when the hook portion is retracted at the time of recovery, the hook portion moves away from the stent body portion, The distance from the stent body can be increased. Therefore, it is possible to prevent the retracting direction from being directed toward the proximal end, and the retracting direction to be suddenly the central axis direction. Therefore, it can reduce that a part of stent main-body part deform | transforms.

  Moreover, the stent concerning this invention WHEREIN: The said connection part may be curved and formed in the wave shape, It may be characterized by the above-mentioned.

  By adopting such a configuration, the length of the connecting portion can be increased, and the distance between the stent body portion and the hook portion can be increased when the hook portion is retracted. Therefore, the retracting direction of the stent body can be directed toward the proximal end side of the stent.

  Furthermore, the stent concerning this invention WHEREIN: The said connection part may have the 1st connection part extended in the separation direction from the connection part of the said stent main-body part, It may be characterized by the above-mentioned.

  By adopting such a configuration, when the hook portion is retracted, the connection direction of the connection portion between the stent body portion and the connection portion is different from the pull-in direction, thereby reducing unnecessary stress from being applied to the connection portion. be able to.

  Furthermore, the stent according to the present invention may include a linear erection part that is erected between the middle part of the coupling part and the stent body part.

  By adopting such a configuration, by pulling the hook portion, the stent body portion can be pulled at two locations: the connection portion between the connection portion and the stent body portion and the connection portion between the installation portion and the stent body portion. It becomes easy to shrink uniformly while holding the circular cross section of the main body.

  Furthermore, in the stent according to the present invention, the erection portion may be curved, bent or folded.

  By adopting such a configuration, the length of the erection part can be increased, and the retracting direction of the end part of the stent body part can be more directed toward the proximal end side.

  Furthermore, in the stent according to the present invention, the connecting portions of the connecting portions and the erection portions with respect to the stent main body portion are arranged evenly with respect to the outer periphery of the proximal end opening of the stent main body portion. It may be a feature.

  By adopting such a configuration, it is possible to prevent a force from being applied non-uniformly to the outer periphery of the end when the stent body is retracted, and the stent body can be easily contracted while maintaining a circular cross section.

  Furthermore, in the stent according to the present invention, the length between the connecting portion of the middle portion of the connecting portion and the connecting portion of the stent body portion and the length of the erected portion are substantially the same length. It may be characterized by.

  By adopting such a configuration, an equal force is applied to the connecting portion of the stent body, so that the stent body can be easily contracted while maintaining a circular cross section.

  Furthermore, in the stent according to the present invention, the connecting portion may be characterized in that it is weaker than the network structure of the stent body or narrower than the network structure of the stent body. Good.

  By adopting such a configuration, it is possible to reduce the possibility that the stent body portion contracts or deforms before the connecting portion is fully extended.

  Furthermore, in the stent according to the present invention, the hook portion may be of a size that can be accommodated in a recovery sheath.

  By adopting such a configuration, even when the hook portion is made of a hard material, it can be collected.

  Furthermore, in the stent according to the present invention, the hook portion may be formed in an arch shape that can be accommodated along an inner peripheral diameter of the recovery sheath.

  By adopting such a configuration, the hook portion can be arranged in the same direction, and the loop can be more easily hooked.

  According to the stent of the present invention, when retracted into the recovery sheath, the degree of contraction becomes uniform, and a stent that can be easily accommodated in the recovery sheath can be provided.

FIG. 1 is a perspective view of a stent 100 according to an embodiment. FIG. 2 is an exploded perspective view of the stent 100 according to the embodiment. FIG. 3 is a diagram schematically illustrating a force applied to the stent 100 when the stent 100 according to the embodiment is disposed in a curved lumen. FIG. 4 shows the stent 100 in a state of being accommodated in the sheath 90. FIG. 5 is a perspective view showing a part of the process of recovering the stent 100. FIG. 6 is a perspective view showing a part of the process of recovering the stent 100. FIG. 7 is a perspective view showing a part of the process of recovering the stent 100. FIG. 8 is a perspective view showing a part of the process of recovering the stent 100.

  Hereinafter, embodiments of the stent 100 according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a stent 100 according to the present embodiment. FIG. 2 is an exploded perspective view of the stent 100 according to the present embodiment. Note that the exploded perspective view in FIG. 2 is not actually disassembled but is disassembled for convenience of explanation. For convenience of explanation, as shown by an arrow in FIG. 1, the side with the hook portion 30 is described as the proximal side, and the side without the hook portion 30 is described as the distal side.

  The stent 100 according to the embodiment is a medical device used for treatment of a body lumen. For example, the stent 100 is disposed in a blood vessel, a urethra, a trachea, a bile duct, a digestive tract, or other lumen to open the lumen, Used to reinforce.

  As shown in FIGS. 1 and 2, the stent 100 mainly includes a stent body 10, a hook portion 30, a connecting portion 50 that connects the stent body 10 and the hook portion 30, an erection portion 70, It has.

  The stent body 10 has a cylindrical shape with open proximal and distal ends. The stent body 10 has a mesh structure made of a linear metal member or plastic, and has an elastic force that expands in the radial direction as a whole. Moreover, it is produced so that the diameter of the stent main-body part 10 may shrink | contract by pulling in a longitudinal axis direction (center axis direction). The form of the network structure is not particularly limited as long as it has the above-described elastic force. Either an open cell or a closed cell may be used. Examples of the metal used for the stent body 10 include stainless steel or biocompatible materials such as tantalum, platinum, gold, cobalt, titanium, and alloys thereof. In particular, it is preferably formed from a material having superelastic characteristics such as cobalt chrome or nickel titanium alloy. Examples of the plastic include nylon (registered trademark). The length and the diameter of the stent body 10 are not particularly limited, and are appropriately selected depending on the affected part to be applied.

  Hereinafter, although it does not limit, an example of the stent main-body part 10 which can be used more suitably is given. As shown in FIG. 2, the stent body 10 includes a plurality of annular bodies 13 arranged side by side in the longitudinal axis direction (that is, the central axis direction) and a coupling body that couples the annular bodies 13 adjacent to each other in the longitudinal axis direction. 15. In the present embodiment, the annular body 13 is formed in a wavy ring shape having four vertices on the proximal end side and four vertices on the distal end side, but the number of vertices is limited. It is not a thing. The connecting body 15 has a closed cell structure in which the respective annular bodies 13 are integrally formed by connecting the distal apex and the proximal apex of the adjacent annular bodies 13 respectively. The connection body 15 is arrange | positioned in parallel along the outer peripheral direction.

  The stent body 10 thus manufactured can be contracted by shortening the diameter of the stent body 10 by folding the wave-like portion of the annular body 13, and the connecting body 15 is elongated from a parallel state in the outer peripheral direction. By moving parallel to the axial direction, the corrugated connector 15 of the annular member 13 adjacent to the portion of the corrugated connector 15 of the annular member 13 is moved and contracted and folded while being contracted. I can do it.

  By using the stent main body 10, even when the stent main body 10 is placed in the curved portion of the lumen, the annular body 13 and the connecting body 15 constituting the stent main body 10 are like an open cell stent. The risk of damaging the tissue of the tubular organ by flaring out to the outside in the radial direction of the stent can be reduced. Further, the annular bodies 13 having a wavy line pattern are connected to each other by the connecting body 15, and the connecting body 15 can be flexibly deformed in the axial direction like a spring. Shape followability to the structure is improved. Furthermore, the annular body 13 having a wavy line pattern easily contracts in the circumferential direction, and the connecting body 15 acting like a spring contracts in the radial direction by extending in the axial direction, so that the stent body 10 can be easily contracted. is there. In addition, since the distortion generated at the outer peripheral edge of the apex of the wavy pattern at the time of expansion or contraction of the stent body 10 is reduced by the lumped portion, for example, blood flow in the blood vessel or pulsation of the blood vessel wall Accordingly, it is possible to reduce the risk of metal fatigue due to the repeated deformation of the apex that accompanies, and to prevent damage to the stent body 10 by improving fatigue resistance.

  As shown in FIG. 1, the hook portion 30 is provided with two hook-shaped hooks 31 at the tip, and the tips of the hook-shaped hooks 31 are both attached to the stent main body 10 when the stent main body 10 is attached. It faces the same side so as to be arranged inside the outer periphery of the portion 10, and is formed to have an arch shape when the hook portion 30 is viewed from the proximal end side. The hook portion 30 is made to have a size that can be accommodated in each sheath so that the hook portion 30 can be accommodated in the sheath 90 used for placement in the lumen and the recovery sheath 20 used for recovery. The hook part 30 may be made of the same material as that of the stent body part 10, or may be made of gold, platinum or the like having high X-ray contrast so that the position can be confirmed by X-rays.

  The connecting part 50 is a member that connects the stent body part 10 and the hook part 30 described above. The end portion of the connecting portion 50 is connected to the outer periphery of the end portion of the stent main body portion 10. Both side end portions of the connecting portion 50 are connected to the stent body portion 10 and are formed by being bent, bent or folded as a whole. In the present embodiment, an example in which the wave is curved is shown. Further, a hook portion 30 is attached to a portion (that is, the center) equidistant from each of the first connection portions 51a and 51a, and the stent body portion 10 and the hook portion 30 are separated by pulling the hook portion 30. be able to. The hook portion 30 is preferably provided in a portion 53 where the apex is formed on the proximal side in the wavy form of the connecting portion 50. By providing the connecting portion (51a) at such a position, the stent body 10 can be easily contracted, and the connecting portion 50 can easily function as a guide when housed in the recovery sheath 210. Further, the hook portion 30 is provided so as to be disposed on the outer periphery of the stent main body portion 10 or in the vicinity of the outer periphery. As shown in FIG. 1, the connecting portion between the connecting portion 50 and the stent body portion 10 is preferably connected to the proximal apex 54 of the corrugated form of the stent body portion 10, and the first connecting portions 51a and 51a are connected. It is good to provide the 1st connection part 52 arrange | positioned so that it may extend toward a proximal end from. By manufacturing in this way, when pulling the hook part 30 to the proximal end side, it is prevented that the stress which bends to the 1st connection parts 51a and 51a is added. Furthermore, the position of the hook part 30 is preferably provided at a position where the hook part 30 is pushed to the outer peripheral side when the first connecting part 52 is pressed. That is, when it arrange | positions in the curved lumen as shown in FIG. 3, when the 1st connection part 52 is pressed by a lumen | bore, when it provides so that the hook part 30 can be pressed on a luminal wall surface. Good. The material used for the connecting portion 50 may be the same material as the stent body 10 or a different material. Preferably, it is made of a material having lower rigidity than the stent material, or formed so as to be a wire material thinner than the wire material of the stent body 10. By adopting such a configuration, it is possible to reduce deformation of the stent body 10 before the connecting portion 50 is deformed linearly when the hook portion 30 is retracted. In the embodiment, the connecting portion 50 is formed as one wire, but two different wires are connected to the first connecting portions 51a and 51a, and the hook portion 30 is connected to each opposite end. It may be provided.

  As shown in FIG. 1, the erection part 70 is a linear member that connects the proximal end part of the stent body part 10 and the middle part of the connection part 50. The erection part 70 is formed to be curved, bent or folded. The length α of the erection part 70 and the length β (see FIG. 6) of the connection part 50 from the connection part between the erection part 70 and the connection part 50 to the first connection part 51a are the same length. It is produced as follows. By forming the hook portion 30 in this way, the same force is applied to the connecting portion of the connecting portion 50 and the erection portion 70 with respect to the stent main body portion 10 when the hook portion 30 is retracted. I can do it. Moreover, it is preferable that the connection part of the construction part 70 and the stent main-body part 10 is connected with the apex 55 of the stent main-body part 10 on the wavy proximal side. By providing the connecting portion at such a position, the stent main body 10 can be easily contracted while maintaining the circular shape of the cross section of the stent body 10, and can be easily functioned as a guide when accommodated in the recovery sheath 210. Furthermore, it is preferable to arrange | position each connection part with the connection part 50 and the installation part 70 so that it may respectively become equidistant with respect to outer periphery. That is, it is preferable that the angle between the adjacent connecting portion and the axis center is 90 degrees. By adopting such a configuration, force is equally applied in the four directions of the proximal end opening of the stent body 10, so that the stent body 10 is easily contracted evenly, and deformation and contraction can be reduced. it can. The material used for the erection part 70 may be made of the same material as that of the stent main body 10 as well as the connecting part 50, or may be made of a different material. Preferably, the stent body 10 is made of a material having a lower rigidity than the material of the stent body 10, or a wire thinner than the wire of the stent body 10 is used. By adopting such a configuration, it is possible to reduce the deformation of the stent main body 10 before the erection portion 70 is linearly deformed. In addition, the connection part of the connection part 50 and the erection part 70, and the stent main body part 10, and the connection part of the connection part 50 and the erection part 70 are respectively connected to the stent main body part 10, the connection part 50, and the erection part 70 separately. For example, the stent body 10, the connecting part 50, and the erection part 70 are simultaneously formed by laser processing, etching processing, or the like for a cylindrical metal cylindrical member, for example, without being limited to a method of connecting in a subsequent process by welding or the like. This includes cases where it is molded.

  Next, the usage method of the stent 100 produced as mentioned above is demonstrated. Prior to use, the stent 100 according to the present embodiment is housed in a sheath 90 for stent placement, as shown in FIG. The stent body 10 is accommodated in a contracted state in the axial center direction, and the hook 30 is accommodated in the sheath 90 as it is as described above.

  After the stent 100 is moved to the affected area while being accommodated in the sheath 90, the stent 100 is pulled out to expose the stent 100 from the sheath 90, so that the stent 100 expands in the lumen by its own expansion force. . Thereby, it arrange | positions in an affected part so that a luminal wall surface may be pressed. As described above, since the stent 100 according to this embodiment has high flexibility, the lumen followability is high, and even a curved portion can be easily adhered to the inner wall surface of the lumen. In addition, since the hook part 30 is disposed at a position close to the stent main body part 10 and at the outer periphery or the vicinity of the outer periphery of the stent main body part 10, the hook part 30 is also easily disposed on the inner wall surface of the blood vessel, which hinders treatment. The resistance to blood flow is reduced.

  In some cases, it is necessary to recover the stent 100 placed for various reasons such as healing of the affected area or replacement of the stent. Hereinafter, the recovery method of the stent 100 according to the present embodiment will be described.

  As shown in FIG. 5, the stent recovery device 200 for recovering the stent 100 includes at least a recovery sheath 210 and a pulling wire 220. The recovery sheath 210 is formed with a diameter that can accommodate at least the hook portion 30. The pulling wire 220 has a loop 221 formed at the tip thereof, so that the hook portion 30 can be hooked. Of course, when the recovery sheath 210 is inserted in addition to these, it is possible to use a guide wire, provide an operating instrument on the hand side, or employ a steer or other instrument.

  The distal end of the recovery sheath 210 is inserted to the vicinity of the indwelling position of the stent 100 by a percutaneous treatment. Then, the pulling wire 220 is inserted from the proximal opening of the recovery sheath 210, the loop 221 at the tip of the pulling wire 220 is pushed out from the distal end opening of the recovery sheath 210, and the loop 221 is expanded. The loop 221 is hooked on the hook portion 30 by operating the pulling wire 220 while observing with an endoscope or through X-ray imaging. When the pulling wire 220 is pulled in this state, as shown in FIG. 6, first, the stent body portion 10 does not move, and the connecting portion 50 and the erection portion 70 are straight from the curved, bent, or folded state. Only the hook part 30 moves to the proximal end side. When the connecting part 50 and the erection part 70 are substantially stretched, the length α of the erection part 70 and the length of the linking part 50 from the connection part between the erection part 70 and the connection part 50 to the first connection part 51a. Since β is formed to have substantially the same length, and the connecting portion 50 and the erection portion 70 are evenly attached to the outer peripheral end portion of the stent main body portion 10, the hook portion 30 is located from the vicinity of the outer periphery to the vicinity of the central axis. Move to. Thereby, the outer periphery of the stent main body 10 is further drawn with an equal force. Further, by pulling the hook portion 30 with the pulling wire 220, the stent body portion 10 is gradually stretched from the distal end side toward the proximal side while being contracted in the central axis direction. At this time, the stent body 10 is peeled off from the inner wall of the lumen. Then, at the same time as the pulling wire 220 is pulled, the stent body 10 is inserted into the recovery sheath 210. At this time, since the connecting portion 50 and the erection portion 70 are first inserted into the recovery sheath 210, the connection portion 50 and the erection portion 70 function as a guide for the stent body 10 as shown in FIG. Will be fulfilled. Further, by further drawing, as shown in FIG. 8, the stent 100 is accommodated in the recovery sheath 210, and after the entire stent 100 is accommodated, the recovery sheath 210 is taken out of the body to remove the stent 100. Removed from the lumen.

  As described above, according to the stent 100 of the present invention, not only the lumen followability of the stent main body portion 10 is good, but also the hook portion 30 can improve followability to the lumen wall surface. Further, since the hook portion 30 is provided at the time of collection, the loop 221 can be easily hooked with the pulling wire 220 provided at the tip, and can be easily pulled in. In addition, since the proximal end opening of the stent body 10 is pulled evenly by the connecting part 50 and the erection part 70 when retracted, the stent body 10 can be easily contracted to the central axis side and linearly formed. Since the connecting portion 50 and the erected portion 70 thus formed serve as a guide to the recovery sheath 210, it is possible to facilitate the drawing into the recovery sheath 210.

  As shown in the embodiment described above, it can be used as a stent.

DESCRIPTION OF SYMBOLS 10 ... Stent body part, 13 ... Ring body, 15 ... Connection body, 30 ... Hook part, 31 ... Hook-shaped hook, 50 ... Connection part, 51a ... 1st connection part, 52 ... 1st connection part, 53 ... part, 54 ... apex, 55 ... apex, 70 ... installation part, 90 ... sheath, 100 ... stent, 200 ... stent recovery device, 210 ... recovery sheath, 220 ... traction wire, 221 ... loop

Claims (10)

In a stent that expands the lumen of the body,
A network-structured stent body having elastic force that expands in the radial direction;
A hook portion provided on one end side of the stent body portion;
The hook portion is bent, bent or folded so as to be separated from the stent main body portion between the hook portion and the stent main body portion, and the hook portion is at or near the outer periphery of the stent main body portion. A connecting portion formed to be disposed;
A stent characterized by comprising:   The stent according to claim 1, wherein the connecting portion is formed in a wave-like shape.   The stent according to claim 1 or 2, wherein the connecting portion has a first connecting portion extending in a separating direction from a connecting portion of the stent main body portion.   The stent according to any one of claims 1 to 3, further comprising a linear erection portion that is erected between the middle portion of the connecting portion and the stent body portion.   The stent according to claim 4, wherein the erection portion is bent, bent, or folded.   The connection part of each said connection part and said installation part with respect to the said stent main-body part is arrange | positioned equally with respect to the outer periphery of the proximal end opening of the said stent main-body part, The Claim 1 to 5 characterized by the above-mentioned. The stent according to any one of the above.   The length between the connection part of the middle part of the connection part and the connection part of the stent main body part and the length of the erection part are substantially the same length. The stent according to any one of the above.   The stent according to any one of claims 1 to 7, wherein the connecting portion has a rigidity that is weaker than that of the network structure of the stent body, or is thinner than the network structure of the stent body. .   The stent according to any one of claims 1 to 8, wherein the hook portion has a size that can be accommodated in a recovery sheath. The stent according to claim 9, wherein the hook portion is formed in an arch shape that can be accommodated along an inner peripheral diameter of the recovery sheath.

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