JP6650664B2 - Filter device - Google Patents

Description

  The present invention relates to a filter device having a filter installed in a blood vessel.

  In the carotid artery region, when plaque or thrombus flows to the peripheral side during stent placement or the like, cerebral blood vessels may be clogged and cerebral infarction may occur. In order to prevent this, a filter has conventionally been known as a filter that captures blood flow from the stenosis portion to the peripheral side without blocking (see Patent Document 1).

JP 2007-117760 A

  For example, in the filter described in Patent Document 1, a proximal slider and a distal slider are provided at the distal and proximal ends of the filter, respectively, and the distal slider and the proximal slider are independent of each other on the guide wire. It is slidably inserted. A stopper is provided between the distal slider and the proximal slider in the guide wire. The stopper can contact the distal slider and the proximal slider, respectively. This allows the filter to move toward the proximal end of the guide wire until the distal slider abuts the stopper, and can also move toward the distal end of the guide wire until the proximal slider abuts the stopper.

  The filter is inserted into the blood vessel via the introduction catheter. The filter housed in the introducer catheter is in a state where the distal slider and the proximal slider are separated and contracted along the guide wire. When the filter is exposed from the introduction catheter, the distal slider and the proximal slider approach each other, and the elastically restored filter expands in the radial direction.

  For example, while confirming the position of the distal slider or the proximal slider by X-rays, inserting the filter into a blood vessel and positioning it at a desired position, and then exposing the filter from the introduction catheter, the expanded The filter can be moved to the distal or proximal side along the guide wire until the distal or proximal slider abuts against the stopper, so the position shift from the position confirmed by X-ray to the distal or proximal side May occur. For example, even if an attempt is made to install a filter on the upstream side immediately before a blood vessel branches, the filter may be expanded downstream from the branch due to positional deviation.

  The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a filter device capable of reliably setting a filter at a desired position in a blood vessel.

  (1) The filter device according to the present invention has a catheter having an accommodation space inside, a wire extending along the longitudinal direction of the catheter in the accommodation space of the catheter, and exposed to the distal end side of the catheter. A filter capable of changing its state to an expanded state that extends outside the outer shape of the catheter, and a contracted state that can be elastically contracted from the expanded state and accommodated in the accommodation space, and provided at the distal end of the filter. A slider that is rotatable about the wire, and is movable along the wire, and is provided on the base end side of the filter, is rotatable about the wire, and And a base-side fixing portion whose movement in the longitudinal direction is restricted.

  With the contracted filter housed in the housing space of the catheter, the catheter is inserted into the blood vessel until the tip of the catheter reaches a desired position in the blood vessel. When the distal end of the catheter reaches a desired position, the filter is exposed from the distal end of the catheter by retracting the catheter proximally with respect to the wire. The base end side of the filter is restricted from moving in the longitudinal direction with respect to the wire rod by the base end side fixing portion. Further, when the filter is elastically expanded from the contracted state, the slider approaches the proximal end side fixing portion. Since both the slider and the proximal-side fixing portion are rotatable about the wire, the filter in the expanded state rotates with respect to the wire so as to follow the inner wall shape of the blood vessel.

  (2) Preferably, the filter device further includes a first stopper fixed to the wire between the slider and the base-side fixing portion.

  For example, when the wire is pushed into the distal end side, the base end side of the filter may be twisted.However, when the slider comes into contact with the stopper, the slider comes closer to the base end side fixing portion than necessary and the filter bends. Too much or breakage is suppressed.

  (3) Preferably, the base-side fixing portion includes a pipe rotatably provided on the wire, and a second stopper fixed to the wire at a distal side and a base end side of the pipe, respectively. It has.

  Thereby, the base end side fixing portion can be realized with a simple structure.

  (4) Preferably, the filter has an opening on the base end side and has a conical shape whose diameter decreases toward the front end side.

  Thereby, the filter is likely to be in an expanded state along the inner diameter and shape of the blood vessel.

  (5) Preferably, the slider and the base-side fixing portion are detectable by radiation.

  Thereby, the installation position of the filter in the blood vessel can be confirmed.

  ADVANTAGE OF THE INVENTION According to this invention, a filter can be reliably installed in the desired position of a blood vessel, without causing a displacement.

FIG. 1 is a diagram illustrating an external configuration of the filter device 10. FIG. 2 is a diagram illustrating a state where the filter 13 is in a contracted state and the catheter 11 is inserted into the blood vessel 30. FIG. 3 is a diagram showing the filter 13 in the blood vessel 30 in an expanded state.

  Hereinafter, preferred embodiments of the present invention will be described. Note that this embodiment is merely an embodiment of the present invention, and it goes without saying that the embodiment can be changed without changing the gist of the present invention.

  As shown in FIG. 1, the filter device 10 is provided on a catheter 11, a shaft 12 (an example of a wire) extending in the catheter 11 along the longitudinal direction of the catheter, and a distal end side of the shaft 12. The filter includes a filter 13 and a tip guide 14 provided at the tip of the shaft 12. The filter device 10 is for inserting the filter 13 into the blood vessel from the distal end side of the catheter 11 and exposing the filter 13 from the distal end of the catheter 11 so that the filter 13 is placed at a desired position in the blood vessel in an expanded state. . FIG. 1 shows the filter device 10 when the filter 13 is in the expanded state.

  The catheter 11 is a tube-shaped member that can be inserted into a target blood vessel, and has a lumen 20 (see FIGS. 2 and 3, an example of an accommodation space) that penetrates a distal end and a proximal end. The catheter 11 has flexibility that can bend along a curve or a branch of a blood vessel. Examples of the catheter 11 include soft vinyl chloride resin, polyolefin such as polyethylene and polypropylene, polyolefin elastomer such as ethylene-propylene copolymer and ethylene-vinyl acetate copolymer, a mixture of polypropylene and polybutene, polyamide, PTFE and ETFE, and the like. For example, a flexible synthetic resin tube such as a fluororesin, a polyamide elastomer, a polyester elastomer, a polyurethane elastomer, or a fluororesin elastomer, and a rubber tube such as a silicone rubber or a latex rubber are preferably used. The outer diameter and length of the catheter 11 are appropriately set according to the position of a target blood vessel or lesion. Although not shown in each figure, a known configuration such as a handle portion for improving operability may be appropriately provided at the proximal end of the catheter 11.

  The shaft 12 is a wire that extends along the longitudinal direction in the lumen 20 of the catheter 11. The shaft 12 has flexibility such that it can bend along a curve or branch of a blood vessel, and rigidity such that the distal end does not bend when the proximal end is pushed in the longitudinal direction. As the shaft 12, a stainless steel wire, a piano wire, a high-tensile steel wire for a spring, a superelastic metal wire, or the like is suitably used. The outer diameter and length of the shaft 12 are appropriately set according to the position of a target blood vessel or lesion and the inner diameter and length of the catheter 11.

  The filter 13 is a conical mesh member having an opening 21 on the base end side and decreasing in diameter toward the distal end side. The opening 21 has a ring shape having a larger diameter than the lumen 20 of the catheter 11. The opening 21 is on the base end side of the shaft 12 and faces in a direction inclined with respect to the axis (longitudinal direction) of the shaft 12. The tip of the filter 13 is closed and faces the tip of the shaft 12. The filter 13 has flexibility to be bent so as to be accommodated in the lumen 20 of the catheter 11. The filter 13 can be housed in the lumen 20 of the catheter 11 in a state where the filter 13 is bent (a contracted state). When the filter 13 goes out of the lumen 20, the filter 13 is elastically restored to have a conical shape (expanded state).

  The material of the filter 13 is preferably, for example, a superelastic alloy such as a nickel-titanium steel wire, a high-strength steel wire for a spring, a metal wire such as a piano wire, or a synthetic resin having a relatively high rigidity such as a polyamide or a fluororesin. Used. The filter 13 is formed by weaving a linear metal or the like. The size of the filter 13 and the annular diameter of the opening 21 are appropriately set according to the target blood vessel and the inner diameter of the catheter 11.

  The filter 13 is connected to the shaft 12 via slide rings 23 and 24 at the tip and the periphery of the opening 21. The slide rings 23 and 24 are ring-shaped members made of a member that can be detected by X-rays such as a stainless steel rope, and the shaft 12 is inserted through the internal space. The filter 13 and the slide rings 23 and 24 are joined by welding or an adhesive. The slide ring 23 (an example of a slider) is rotatable about the shaft 12 and is slidable with respect to the shaft 12 in the longitudinal direction. The tip of the filter 13 joined to the slide ring 23 is rotatable about the shaft 12 together with the slide ring 23 and is slidable with respect to the shaft 12 in the longitudinal direction.

  The slide ring 24 (an example of a tube) is sandwiched between a pair of stoppers 25 and 26 (an example of a second stopper) fixed to the distal end side of the shaft 12. The stoppers 25 and 26 are ring-shaped members made of stainless steel or the like, and are fixed to the shaft 12 in a state where the shaft 12 is inserted into the internal space. The stoppers 25 and 26 do not rotate with respect to the shaft 12 and do not move in the longitudinal direction. The slide ring 24 sandwiched between the stoppers 25 and 26 is rotatable about the shaft 12, and is restricted from moving in the longitudinal direction with respect to the shaft 12. The periphery of the opening 21 of the filter 13 fixed to the slide ring 24 is rotatable around the shaft 12 and is restricted from moving in the longitudinal direction with respect to the shaft 12.

  A stopper 27 (an example of a first stopper) is provided on the shaft 12 between the slide rings 23 and 24. The stopper 27 is a ring-shaped member made of a stainless steel rope or the like, and is fixed to the shaft 12 in a state where the shaft 12 is inserted into its internal space. The stopper 27 does not rotate with respect to the shaft 12 and does not move in the longitudinal direction. The stopper 27 is disposed at a position where the slide ring 24 abuts or approaches a close distance in the filter 13 in the expanded state. The contact with the stopper 27 restricts the movement of the slide ring 23 from the position of the stopper 27 toward the slide ring 24.

  The tip guide 14 is fixed to the tip of the shaft 12. The tip guide 14 projects from the tip of the shaft 12 along the axis of the shaft 12. The distal end guide 14 has a fitting portion 28 fitted to the distal end of the catheter 11 and a guide portion 29 protruding from the fitting portion 28. The fitting portion 28 is made of a synthetic resin, and when a part of the distal end of the catheter 12 enters the lumen 20, the fitting portion 28 fits with the catheter 11 in a state where the distal end of the lumen 20 is sealed. The guide portion 29 is formed by winding a stainless steel rope in a spiral shape, and is elastically curved along a curve or a branch of a blood vessel.

[How to use the filter device 10]
Hereinafter, a method of using the filter device 10 will be described with reference to FIGS. 2 and 3, only the outer shape of the filter 13 is shown.

  As shown in FIG. 2, the filter device 10 is inserted into the blood vessel 30 with the filter 13 contracted and housed in the lumen 20 of the catheter 11, and the distal guide 14 fitted to the distal end of the catheter 11. . The filter device 10 is inserted into the blood vessel 30 from the distal guide 14 side, and the insertion method into the blood vessel 30 is the same as that of a general catheter. Whether the filter device 10 has been inserted to a desired position in the blood vessel 30 is determined by confirming the positions of the slide rings 23 and 24 by X-ray irradiation.

  When the distal side of the catheter 11, that is, the slide rings 23 and 24 reach a desired position in the blood vessel 30, the catheter 11 is pulled back to the proximal side with respect to the shaft 12 at the proximal side of the filter device 10, that is, outside the body. When the distal end guide 14 comes off the distal end of the catheter 11 and the catheter 11 is further pulled back to the proximal end side, the contracted filter 13 is exposed to the outside from the distal end of the catheter 11. The catheter 11 pulled back to the proximal side is completely pulled out of the body.

  The peripheral edge of the opening 21 on the base end side of the filter 13 is restricted from moving in the longitudinal direction with respect to the shaft 12 by the slide ring 24 and the stoppers 25 and 26. The distal end of the filter 13 is slidable along the shaft 12 toward the slide ring 24 along with the slide ring 23. The slide ring 23 slides along with the catheter 11 toward the slide ring 24 due to friction with the inner wall of the catheter 11. However, when the slide ring 23 comes into contact with the stopper 27, the filter 13 may approach the slide ring 24 more than a distance required for the slide ring 23 to be expanded and the filter 13 may be excessively bent or damaged. Absent.

  As shown in FIG. 3, when the filter 13 in the contracted state is exposed to the outside through the lumen 20 of the catheter 11, the filter 13 is elastically returned to the expanded state. When the filter 13 changes from the contracted state to the expanded state, the slide ring 23 slides along the shaft 12 until it comes into contact with or approaches the stopper 27, but the slide ring 24 does not move in the longitudinal direction of the shaft 12. Therefore, the filter 13 is expanded without moving from the position of the slide ring 24 confirmed by X-ray irradiation. Further, since the slide rings 23 and 24 are both rotatable about the shaft 12, the filter 13 in the expanded state rotates with respect to the shaft 13 along the inner wall shape of the blood vessel 30.

  Although not shown in each of the drawings, after the filter 13 is placed in an expanded state at a desired position in the blood vessel 30, a balloon catheter or the like is inserted into the blood vessel 30 to expand or cut off a stenosis (emboli). Done. Since the filter 13 is indwelled on the downstream side of the blood flow from the stenosis, the embolus separated from the stenosis by the operation is captured by the filter 13.

  When the filter 13 is collected from the blood vessel 30, the reverse procedure is performed. That is, the catheter 11 is fed from the proximal end side of the shaft 12 to the distal end side, and the filter 13 in the expanded state is accommodated in the lumen 20 of the catheter 11. When the distal end of the catheter 11 moves toward the distal end while abutting on the periphery of the opening 12 of the filter 13, the filter 13 elastically contracts in accordance with the lumen 20, whereby the filter 12 contracts from the expanded state. It elastically changes to a state. With the filter 13 housed in the lumen 20, the filter device 10 is withdrawn from the blood vessel 30.

[Operation and effect of the present embodiment]
According to the filter device 10 according to the present embodiment, the slide ring 23 provided on the distal end side of the filter 13 is rotatable around the shaft 12, is movable along the shaft 12, and The slide ring 24 provided on the proximal end side is rotatable about the shaft 12 and its movement in the longitudinal direction with respect to the shaft 12 is regulated, so that the filter 13 is placed at a desired position of the blood vessel 30. Even if the catheter 11 is pulled back to the proximal end after being positioned, the filter 13 can be reliably installed at a desired position of the blood vessel 30 without causing the filter 13 to be displaced.

  Since the stopper 27 is fixed to the shaft 12 between the slide rings 23 and 24, when the shaft 12 is further pushed into the distal end side, the base end side of the filter may be twisted. Is in contact with the stopper 27, so that the filter 13 is prevented from being excessively bent or damaged by approaching more than a distance necessary for the slide ring 23 to be expanded to the slide ring 24 side.

[Modification]
In the above-described embodiment, the stopper 27 is fixed to the shaft 12 between the slide rings 23 and 24. For example, when the filter 13 is made of a material that is hardly bent or damaged, the stopper 27 is provided. It is not necessary.

  In the above-described embodiment, the slide ring 24 provided on the shaft 12 is sandwiched between the stoppers 25 and 26, so that the slide ring 24 is rotatable around the shaft 12, and Although the movement in the longitudinal direction is restricted by this, the base-side fixing portion according to the present invention may be realized by a different configuration. For example, a part of the shaft 12 may be deformed into a convex shape so that the slide ring 24 cannot move in the longitudinal direction.

  Further, in the above-described embodiment, the filter 13 has the opening 21 on the base end side, and has a conical shape in which the diameter is reduced toward the distal end and the filter 13 is closed. Or other shapes such as hemispherical shapes.

  In the above-described embodiment, the slide rings 23 and 24 can be detected by X-rays. However, instead of the slide rings 23 and 24, the stoppers 25, 26 and 27 and the tip guide 14 can be detected by X-rays. It may be configured.

  In the filter device 10 described above, the filter 13 may be formed of a flexible material, and a core may be provided along the periphery of the opening 21 of the filter 13. This core material is elastically deformed so as to be accommodated in the lumen 20 of the catheter 11. The filter 13 can be accommodated in the lumen 20 of the catheter 11 in a state where the core material is elastically deformed and the filter 13 is bent (contracted state). When the filter 13 goes out of the lumen 20, the core material elastically returns and becomes annular, and accordingly, the entire shape of the filter 13 becomes conical.

  Further, the above-described filter device 10 may be used not only in the carotid artery region but also in the coronary artery region and the shunt region.

10 filter device 11 catheter;
12 shaft (wire material)
13 filters 20 lumens (accommodation space)
23 Slide ring (slider)
24 slide ring (tube, base end fixed part)
25, 26 stopper (second stopper, base side fixed part)
27 Stopper (first stopper)

Claims (4)

A catheter having an accommodation space inside,
A wire extending along the longitudinal direction of the catheter in the accommodation space of the catheter,
A filter in which a superelastic metal wire is woven, the expanded state being exposed to the distal end side of the catheter and returning to a shape expanded to the outside from the outer shape of the catheter, and the elastically contracting from the expanded state, A filter that can change its state to a contracted state that can be stored in the storage space,
A slider provided on the tip side of the filter, rotatable around the wire, and movable along the wire;
A base-side fixed portion that is provided on the base end of the filter, is rotatable around the wire, and is restricted from moving in the longitudinal direction with respect to the wire,
A first stopper fixed to the wire between the slider and the base-side fixed portion,
The base-side fixing portion is
A tube rotatably provided on the wire rod,
And a second stopper fixed to the wire at a distal end side and a proximal end side with respect to the tubular body, respectively.   2. The filter device according to claim 1, wherein the filter has an opening on a base end side, and has a conical shape whose diameter decreases toward a distal end side. 3.   The filter device according to claim 1, wherein the slider and the base-side fixing portion are detectable by radiation.   4. The filter device according to claim 1, wherein the slider is located at a short distance from the first stopper when the filter is in the expanded state.

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