JP6624645B2 - Stent delivery system and delivery wire - Google Patents

Description

  The present invention relates to a stent delivery system and a delivery wire.

  The following pusher guidewires are known. With this pusher guidewire, the stent can be released from the distal end of the catheter to a target site by pushing the delivery wire toward the distal end while the stent is stored at the distal end of the catheter (for example, Patent Document 1). .

JP 2014-213141 A

  Self-expanding stents self-expand in a blood vessel when released from the catheter, thereby being deployed in the blood vessel. However, the expandability of the stent may not be good at sites where the stent is difficult to self-expand, such as a meandering blood vessel.In such a case, the operator pushes the stent while pushing it with a microcatheter. It was necessary to expand the stent or to expand the stent by inserting a balloon catheter at a location where the expansion of the stent was not sufficient.

A stent delivery system according to the present invention is a stent delivery system including a self-expanding stent and a delivery wire operated to release the stent into a blood vessel, wherein a distal end portion of the delivery wire includes a stent sheath. When pushed out from the central part of the delivery wire, it is processed so that the outer diameter is deformed into a convex shape larger than the inner diameter of the stent sheath, and the part of the stent released into the blood vessel is not sufficiently expanded. Is pushed in the direction of expansion by the convex portion so that expansion of the stent can be assisted.
Delivery wire according to the present invention is a delivery wire which is operated to release the self-expanding stent into a blood vessel, in its front end portion, when pushed out of the stent sheath relative to the center axis of the delivery wire The outer side is processed so that the outer diameter is deformed into a convex shape larger than the inner diameter of the stent sheath, and the part where the stent released into the blood vessel is not sufficiently expanded is pushed in the expansion direction with the convex part to assist the expansion of the stent. It is characterized by being made possible.

  According to the present invention, since the distal end of the delivery wire is processed to have a shape to assist the expansion of the stent, even when a portion where the stent is not sufficiently expanded occurs, the distal end of the delivery wire is used. To expand the stent.

It is a figure showing typically composition of one embodiment of a stent delivery system. It is the 1st figure which showed typically the shape of the delivery wire in this invention. It is the 2nd figure which showed typically the shape of the delivery wire in the present invention. It is the figure which showed typically the example of the expansion method of the stent using the delivery wire in this invention. It is the 3rd figure which showed typically the shape of the delivery wire in this invention.

  FIG. 1 is a diagram schematically illustrating a configuration of an embodiment of a stent delivery system according to the present embodiment. FIG. 1 shows a case where the stent delivery system 10 is viewed from the side, and the left side of the figure is a distal end side inserted into a patient's body, and the right side is a rear end side operated by an operator such as a doctor. Is shown in The stent delivery system 10 includes a stent sheath 11, a delivery wire 12, and a stent 13. In the present embodiment, the stent 13 is assumed to be a self-expanding self-expandable stent.

  In the stent delivery system 10 according to the present embodiment, the operator connects the stent delivery system 10 to a microcatheter inserted into a blood vessel of a patient, operates the delivery wire 12 for stent delivery, and attaches the stent 13 to the stent. After being pushed out of the sheath 11 into the microcatheter and moved to the target site, it is released from the distal end of the catheter.

  As shown in FIG. 1, the delivery wire 12 is configured by joining a front end coil 12a and a rear end coil 12b to a core shaft 12f. That is, the distal end side of the core shaft 12f, which is the core wire of the delivery wire 12, has a coil 12e made of an X-ray opaque material such as platinum, and the distal end side coil 12a having a spherical end is joined. The rear end side coil 12b made of a metal material such as stainless steel is joined to the rear end side of the core shaft 12f. Further, the delivery wire 12 is provided with a stent pusher ring 12c and a stent pull ring 12d for moving the stent with a stent marker described later as a contact point.

  When the operator pushes the delivery wire 12 in the distal direction, the stent marker 13a provided on the distal side of the stent 13 is pushed out in the distal direction by the stent pusher ring 12c. Move distally within the catheter. Further, when the operator pulls the delivery wire 12 forward, the stent marker 13b provided on the rear end side of the stent 13 is pulled back toward the rear end by the stent pull ring 12d. Or within the microcatheter in the posterior direction. As described above, the surgeon can adjust the position of the stent 13 by operating the delivery wire 12.

  When the stent 13 is released from the microcatheter, it expands in the blood vessel, and is placed in an affected part such as an aneurysm. As described above, since the stent 13 is a self-expandable self-expandable stent, it is self-expanded in a blood vessel when released from the microcatheter, but the expansion may be insufficient. For example, in a portion where a blood vessel is meandering, the stent is difficult to self-expand, and when the stent 13 is released to such a site, the expansion of the stent 13 may not be sufficient. Also, the stent may be difficult to self-expand for other reasons.

  Conventionally, when the stent 13 is not sufficiently expanded when released into a blood vessel, the operator expands the stent 13 while pushing it with a microcatheter, or inserts a balloon catheter into a place where the expansion of the stent 13 is not sufficient. Had to be expanded.

  In the stent delivery system 10 according to the present embodiment, as shown in FIGS. 2 and 3, by using a delivery wire 12 having a distal end processed to have a shape for assisting the expansion of the stent 13. Even when the stent 13 is not sufficiently expanded when released into the blood vessel, the stent 13 can be easily expanded.

  Hereinafter, the delivery wire 12 according to the present embodiment will be described. As shown in FIG. 2, the distal end portion of the delivery wire 12 is moved with respect to the central axis 2 a of the delivery wire 12 so that a portion of the stent 13 where expansion is insufficient is pushed out and expanded. The shape is such that it is convex outward. In the example shown in FIG. 2, the stent mount portion between the stent pusher ring 12c and the stent pull ring 12d is shaped so as to protrude outward with respect to the central axis 2a of the delivery wire 12. In the present embodiment, the shape of this portion is a wavy shape processed so that the delivery wire 12 is bent at the peak portion shown in FIG. 2, or the peak portion shown in FIG. It is assumed to be one of spiral shapes processed into a spiral so as to form an outer peripheral portion.

  For example, if the stent mount portion has a wavy shape, the shape when the delivery wire 12 is viewed from the distal end side in the direction of the arrow 2c is as shown in FIG. Further, when the stent mount portion is formed in a spiral shape, the shape when the delivery wire 12 is viewed from the distal end side in the direction of the arrow 2c is as shown in FIG. 3B. The length 2b between the peaks in the direction perpendicular to the central axis 2a shown in FIG. 2 corresponds to the length 2b between the peaks in FIG. 3 (a), and the spiral portion in FIG. 3 (b). Corresponds to the diameter 2b. Since the length 2b shown in FIGS. 2 and 3 corresponds to the outer diameter of the processed portion of the delivery wire 12 as viewed from the center axis 2a, the length 2b is referred to as the outer diameter 2b in the present embodiment.

  In the present embodiment, the stent mount portion of the delivery wire 12 is processed into a wavy shape or a spiral shape within the elastic range of the material of the core shaft 12f, which is the core wire. It is designed to be smaller and larger than the inner diameter of the stent sheath 11. For example, stainless steel or a nickel-titanium alloy is used as a material of the core shaft 12f. Further, the outer diameter 2b of the wavy shape or the spiral shape is set to 3.0 mm when the inner diameter of the stent 13 at the time of expansion is 4.0 mm and the inner diameter of the stent sheath 11 is 0.6 mm.

  The delivery wire 12 is stored in the stent sheath 11 in a state where the stent mount portion has a straight shape. Accordingly, the stent mount portion moves in a straight shape in the stent sheath 11 and the microcatheter, similarly to a general stent delivery system.

  When the stent mount portion of the delivery wire 12 is pushed out of the microcatheter, as described above, the stent mount portion of the delivery wire 12 has an outer diameter in a wavy shape or a spiral shape within the elastic range of the material of the core shaft 12f. Since it is processed so as to be larger than the inner diameter of 11, the stent mount portion is deformed into a wavy shape or a spiral shape. At this time, since the outer diameter 2b in the wavy shape or the spiral shape is designed to be smaller than the expanded diameter of the stent 13, the outer diameter 2b can be moved inside the stent 13 after expansion.

  FIG. 4 is a schematic diagram showing a method in which the operator operates the delivery wire 12 to expand the stent 13 when the stent 13 released into the blood vessel is not sufficiently expanded in the stent delivery system 10 according to the present embodiment. FIG.

  FIG. 4A shows a state where the rear end portion of the stent 13 is not sufficiently expanded when the stent 13 is released to the aneurysm 4b of the blood vessel 4a. When the distal end portion of the delivery wire 12 shown in FIG. 4 has a wavy shape, the operator pulls the delivery wire 12 back to the rear end side, pushes the delivery wire 12 toward the distal end side, and rotates the delivery wire 12 to rotate. The stent 13 is extruded outward at the wavy crest portion to assist the expansion of the stent 13. Thereby, as shown in FIG. 4B, the unexpanded portion of the stent 13 can be expanded.

  When the distal end of the delivery wire 12 shown in FIG. 4 has a spiral shape, the operator pulls the delivery wire 12 back to the rear end, pushes the delivery wire 12 toward the distal end, or rotates the delivery wire 12 to rotate the delivery wire 12. The outer periphery of the spiral shape pushes the stent 13 outward to assist in the expansion of the stent 13. Thereby, as shown in FIG. 4B, the unexpanded portion of the stent 13 can be expanded.

According to the embodiment described above, the following operational effects can be obtained.
(1) The stent delivery system 10 includes a self-expanding stent 13 and a delivery wire 12 that is operated to release the stent 13 into a blood vessel. It is made to be processed so as to have a shape for making. Thus, even when the expansion of the stent 13 is insufficient, the expansion of the stent 13 is assisted by the delivery wire 12, and the stent 13 can be sufficiently expanded in the blood vessel.

(2) The delivery wire 12 has a spiral shape on the distal end side, so that the stent 13 is pushed outward at the outer peripheral portion of the spiral shape, thereby assisting the expansion of the stent 13. Thereby, even when the expansion of the stent 13 is not enough, the operator pushes the stent 13 outward at the outer peripheral portion of the spiral shape by operating the delivery wire 12 processed so as to have the spiral shape. Thereby, the stent 13 can be expanded.

(3) The spiral shape of the delivery wire 12 is such that the outer diameter of the spiral portion is smaller than the expanded diameter of the stent 13 and larger than the inner diameter of the stent sheath 11 in which the stent 13 is housed. Thus, by making the outer diameter of the spiral portion smaller than the expanded diameter of the stent 13, the spiral portion of the delivery wire 12 can be moved within the expanded stent. Further, by making the outer diameter of the spiral portion larger than the inner diameter of the stent sheath 11, when the distal end portion of the delivery wire 12 is pushed out of the microcatheter, the shape of the distal end portion can be restored to the spiral shape.

(4) The delivery wire 12 has a wavy shape on the distal end side, and pushes the stent 13 outward at the wavy ridge, thereby assisting the expansion of the stent 13. Accordingly, even when the stent 13 is not sufficiently expanded, the surgeon can push the stent 13 outward at the wavy crest by operating the delivery wire 12 processed so as to have a wavy shape. Thereby, the stent 13 can be expanded.

(5) The wavy shape of the delivery wire 12 is such that the outer diameter of the peak is smaller than the expanded diameter of the stent 13 and larger than the inner diameter of the stent sheath 11 in which the stent 13 is housed. In this manner, by making the outer diameter of the ridge smaller than the expanded diameter of the stent 13, the ridge of the delivery wire 12 can be moved within the expanded stent. In addition, by making the outer diameter of the peak portion larger than the inner diameter of the stent sheath 11, when the distal end portion of the delivery wire 12 is pushed out of the microcatheter, the shape of the distal end portion can be restored to a wavy shape.

-Modified example-
The above-described embodiment can be modified as follows.
(1) In the above-described embodiment, when the distal end portion of the delivery wire 12 is formed in a spiral shape, as shown in FIG. 2 and FIG. The example in which the spiral portion is configured to be spiral has been described. However, as shown in FIG. 5, the central axis 2a of the delivery wire 12 and the central axis 5a of the spiral portion may be shifted. As a result, the distance from the central axis of the delivery wire 12 to the outer periphery of the spiral portion becomes longer, so that the stent 13 can be expanded further outward.

(2) In the above-described embodiment, as shown in FIG. 2, the delivery wire 12 is processed so that the ridges appear one by one at the top and bottom, but the number of ridges is not limited to this. For example, in the case of the wavy shape in the above-described embodiment, the delivery wire 12 is bent so that the wavy portion appears one by one at the top and bottom, but two or more hills at the top and bottom appear. May be bent. Further, in the case of the spiral shape in the above-described embodiment, the spiral portion is processed so that the delivery wire 12 makes one round in a spiral shape so that one mountain appears at each of the upper and lower portions. The number of peaks appearing in the vertical direction may be two or more in the case of the circumference or more. The spiral shape may be right-handed or left-handed.

  Note that the present invention is not limited to the configuration in the above-described embodiment as long as the characteristic functions of the present invention are not impaired. Further, a configuration in which the above-described embodiment and a plurality of modified examples are combined may be adopted.

Reference Signs List 10 stent delivery system 11 stent sheath 12 delivery wire 13 stent

Claims (10)

A self-expanding stent;
A delivery wire that is manipulated to release the stent into a blood vessel.
The distal end portion of the delivery wire is processed so as to be deformed into a convex shape having an outer diameter larger than the inner diameter of the stent sheath outwardly with respect to the central axis of the delivery wire when pushed out of the stent sheath . A stent delivery system characterized in that a portion of the stent that has not been sufficiently expanded and that has not been sufficiently expanded is pushed in a direction of expansion by a convex portion so that expansion of the stent can be assisted. The stent delivery system according to claim 1,
The delivery wire according to claim 1, wherein the distal end portion is formed in a spiral shape, and a portion of the outer peripheral portion of the spiral shape where the expansion of the stent is not sufficient is pushed in the expansion direction, thereby assisting the expansion of the stent. Delivery system. The stent delivery system according to claim 2,
The stent delivery system, wherein the spiral shape has an outer diameter of a spiral portion smaller than an expanded diameter of the stent and larger than an inner diameter of a stent sheath in which the stent is housed. The stent delivery system according to claim 1,
The delivery wire according to claim 1, wherein the distal end portion has a wavy shape, and a portion where the stent is not sufficiently expanded at a wavy crest portion is pushed in an expanding direction, thereby assisting the expansion of the stent. Delivery system. The stent delivery system according to claim 4,
The corrugated shape is a stent delivery system, wherein an outer diameter of a peak portion is smaller than an expanded diameter of the stent and larger than an inner diameter of a stent sheath in which the stent is housed. A delivery wire that is manipulated to release a self-expanding stent into a blood vessel,
When the distal end portion is extruded from the stent sheath, it is processed outward to the central axis of the delivery wire so that the outer diameter is deformed into a convex shape larger than the inner diameter of the stent sheath , and released into the blood vessel. A delivery wire characterized in that a portion where expansion of the stent is insufficient is pushed by a convex portion in an expansion direction to assist expansion of the stent. The delivery wire according to claim 6,
A delivery wire, wherein the distal end portion is formed in a spiral shape, and a portion of the outer peripheral portion of the spiral shape where expansion of the stent is not sufficient is pushed in an expansion direction, thereby assisting expansion of the stent. The delivery wire according to claim 7,
The delivery wire according to claim 1, wherein an outer diameter of the spiral portion is smaller than an expanded diameter of the stent and larger than an inner diameter of a stent sheath in which the stent is housed. The delivery wire according to claim 6,
A delivery wire, wherein the distal end portion has a wavy shape, and a portion of the wavy crest portion where the stent is not sufficiently expanded is pushed in an expanding direction to assist in expanding the stent. The delivery wire according to claim 9,
The delivery wire according to claim 1, wherein the wavy shape has an outer diameter of a peak portion smaller than an expanded diameter of the stent and larger than an inner diameter of a stent sheath in which the stent is housed.

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