JP2023087462A - stent delivery device - Google Patents

Abstract

To provide a stent delivery device capable of smoothly bending a sheath.SOLUTION: A stent delivery device includes: an inner sheath 30; a stent; a reinforcement material (a metal pipe 7 and an outer tube 8) mounted on an outer surface of the inner sheath 30, which is disposed on a proximal side with respect to a stent graft 2; a pusher 6; and an outer sheath 31. The reinforcement material includes the metal pipe 7 covering the surrounding of the inner sheath 30 and a resin tube (the outer tube 8) covering the surrounding of the metal pipe 7. The metal pipe 7 includes a swaging part 7c, and the inner sheath 30 and the metal pipe 7 are fixed by the swaging part 7c. The outer tube 8 is disposed so as to cover the swaging part 7c.SELECTED DRAWING: Figure 4

Description

The present invention relates to a stent delivery device for medical use and for delivering a stent into the body.

2. Description of the Related Art In medical practice, a stent delivery device is used to deliver an indwelling device such as a stent (including a stent graft) into the body. The sheath of the stent delivery device is inserted into the body in order to deliver such items into body passages (including digestive tracts, blood vessels, etc.). According to such a stent delivery device, the stent held within the sheath can be left in the body.

For example, in Patent Document 1, as a device for delivering a stent into the body, an inner sheath (described as a shaft in the same document), an outer sheath (described as a sheath in the same document), an inner sheath and an outer A stent delivery device (described in the same document as is described as a delivery device.) is disclosed.
The stent is exposed from the outer sheath by moving the outer sheath to the base end side (proximal side) relative to the inner sheath, so that the stent can be left in the body canal.

JP-A-2004-223262

The stent delivery device described in Patent Document 1 includes an inner sheath, a stent or pusher, and an outer sheath in order from the inner side in the radial direction.
Because it is composed of multiple components in the radial direction, when the sheath (inner sheath, outer sheath, pusher, etc.) is bent, each component may be separated unintentionally, In some cases, the displacement in the direction of bending may be inhibited. In other words, in the stent delivery device described in Patent Document 1, there is room for improvement regarding smooth bending of the sheath.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems described above, and provides a stent delivery device capable of smoothly bending a sheath.

The stent delivery device of the present invention comprises an inner sheath, a stent mounted around the inner sheath, a reinforcing member mounted on the outer surface of the inner sheath and disposed proximal to the stent, and a pusher mounted around the inner sheath and the reinforcing member and disposed proximal to the stent; and an outer sheath covering the inner sheath, the stent, and the pusher from the outside in the radial direction, The reinforcing member has a metal pipe that surrounds the inner sheath and a resin tube that surrounds the metal pipe, the metal pipe has a crimped portion, and the inner sheath and the metal pipe are , and the resin tube is arranged to cover the crimped portion.

It is possible to provide a stent delivery device capable of smoothly bending the sheath.

FIG. 3 is a schematic diagram showing a state in which a stent graft is indwelled in the aortic arch by a stent delivery device (delivery device). 1 is an external view of a delivery device; FIG. It is a schematic diagram which mainly shows a metal pipe. FIG. 4 is a cross-sectional view showing a vertical cross section of the sheath corresponding to IV section of FIG. 3; FIG. 4 is a cross-sectional view showing cross sections of an inner sheath and a metal pipe;

A stent delivery device (delivery device 1) according to an embodiment of the present invention will be described below.
The drawings used in this embodiment illustrate the configuration, shape, and arrangement of each member of the stent delivery device of the present invention, and do not limit the present invention.
Also, the drawings do not necessarily accurately represent the dimensional ratios of the length, width, and height of the stent delivery device.
In addition, the proximal side (base end side) refers to the side arranged near the operator during treatment, and the distal side (tip side) refers to the side arranged far from the operator during treatment.
Moreover, in all the drawings, the same constituent elements are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate.

<Overview>
Prior to the description of this embodiment, first, the outline of a stent delivery device (delivery device 1) according to this embodiment will be described mainly with reference to FIGS. 1 to 4. FIG.
FIG. 1 is a schematic diagram showing a state in which a stent graft 2 is indwelled in an aortic arch 50 by a stent delivery device (delivery device 1). 2 is an external view of the delivery device 1, FIG. 3 is a schematic diagram mainly showing the metal pipe 7, and FIG. 4 is a sectional view showing a longitudinal section of the sheath 3 corresponding to the IV section of FIG.
3 shows a state in which the connector 4 shown in FIG. 2, the outer tube 8 shown in FIG. 4, the pusher 6, the outer sheath 31 shown in FIG. 4, and the stent graft 2 shown in FIG. 1 are removed.

The stent delivery device (delivery device 1) according to the present embodiment includes an inner sheath 30, a stent (stent graft 2) mounted around the inner sheath 30, and a stent graft 2 mounted on the outer surface of the inner sheath 30 and closer than the stent graft 2. The reinforcing member (metal pipe 7, outer tube 8) arranged on the proximal side, and the inner sheath 30 and the reinforcing member (metal pipe 7, outer tube 8) are mounted on the proximal side of the stent graft 2. and an outer sheath 31 that covers the inner sheath 30, the stent graft 2, and the pusher 6 from the outside in the radial direction.
The reinforcing member has a metal pipe 7 that surrounds the inner sheath 30 and a resin tube (outer tube 8 ) that surrounds the metal pipe 7 .
The metal pipe 7 has crimped portions 7b, 7c, 7d and 7e, and the inner sheath 30 and the metal pipe 7 are fixed by the crimped portions 7b, 7c, 7d and 7e.
The outer tube 8 is arranged so as to cover the crimped portions 7b, 7c, 7d and 7e.

A "stent" is a stent graft 2 comprising a stent portion 2a and a resin graft portion 2b in the blood vessel described in this embodiment. However, the stent is not limited to such a structure. For example, when it is used for respiratory system or digestive system body canals, the stent part 2a is formed only without the graft part 2b. There may be.

Also, the outer tube 8 is formed to cover at least a portion of the metal pipe 7 including the crimped portions 7b, 7c, 7d and 7e.
Although an example in which four crimped portions 7b, 7c, 7d, and 7e are formed in the axial direction in the metal pipe 7 according to this embodiment, the present invention is not limited to such a configuration. The number of crimped portions 7b, 7c, 7d, and 7e can be arbitrarily set, and preferably two or more, more preferably three or more are provided in the axial direction.

According to the above configuration, since the inner sheath 30 and the metal pipe 7 are fixed by the crimped portions 7b, 7c, 7d, and 7e, when the inner sheath 30 is fixed over a wide range in the axial direction, the adhesive fixing is biased. It can be fixed evenly compared to adhesives that tend to be glued.
In addition, since the crimped portions 7b, 7c, 7d, and 7e are covered with the outer tube 8, contact with the inner surface of the pusher 6 can be prevented. Therefore, even when the sheath 3 is about to bend and the pusher 6 is about to be displaced with respect to the reinforcing material (metal pipe 7), the crimped portions 7b, 7c, 7d, and 7e do not hinder the displacement of the pusher 6. .

<Configuration of each part>
The configuration of each part of the delivery device 1 will be described with reference to the drawings.
The delivery device 1 delivers the stent graft 2 into the body (inside the body vessel) as described above. The delivery device 1 includes a long sheath 3, a stent graft 2 housed in the sheath 3, a pusher 6 for restricting movement of the proximal side of the stent graft 2, and reinforcing materials (a metal pipe 7 and an outer tube 8). , is mainly provided.
The placement site of the stent graft 2 by the delivery device 1 in this embodiment is the site of the aortic arch 50 shown in FIG. 1 where the aortic aneurysm 40 is located.

The stent graft 2 according to this embodiment is attached to the inner sheath 30, and is exposed from the sheath 3 when the outer sheath 31 is moved proximally relative to the inner sheath 30 by the operator. .
As described above, the stent graft 2 includes a stent portion 2a made of metal (eg, nickel-titanium alloy) and a graft portion 2b made of resin. A portion of the stent portion 2a is arranged in a mesh within the graft portion 2b, and another portion of the stent portion 2a extends from the distal end portion and is attached to the distal end portion of the inner sheath 30. As shown in FIG.

The sheath 3 according to this embodiment includes an inner sheath 30, a metal pipe 7, an outer tube 8, a pusher 6, and an outer sheath 31 in this order from the radial center to the outside.
In this embodiment, the guide wire 34 is passed through the inner sheath 30 and the distal tip 5 attached to the distal end of the inner sheath 30 and is guided to the placement site of the stent graft 2 in the aortic arch 50 .

The pusher 6 restricts the movement of the stent graft 2 on the proximal side, and is arranged at a position overlapping the stent graft 2 accommodated in the outer sheath 31 in the radial direction. In this embodiment, the inner surface of the pusher 6 is sized to contact the outer surface of an outer tube 8, which will be described later. It is formed in a size spaced apart from the inner surface of 31 .

The delivery device 1 includes a gripping portion 9 for fixing the proximal end portions of the reinforcing material (the metal pipe 7 and the outer tube 8 ), the inner sheath 30 and the pusher 6 .
Inside the grip portion 9, the inner sheath 30 and the metal pipe 7 are fixed to each other with an adhesive 7a.
The crimped portions 7b, 7c, 7d, and 7e are arranged outside the grip portion 9 on the distal side, and the crimped portions 7b, 7c, 7d, and 7e are not provided with the adhesive 7a.

As shown in FIG. 3, the adhesive 7a in this embodiment extends from the inside to the outside of the gripping portion 9 in the axial direction, between the inner sheath 30 and the metal pipe 7, and between the metal pipe 7 and the outer tube. 8 is applied.
The adhesive 7a applied between the metal pipe 7 and the outer tube 8 may be provided only within the grip portion 9. In other words, the tip side of the metal pipe 7 does not have to be joined to the tip side of the outer tube 8 .

According to the above configuration, the inner sheath 30 and the metal pipe 7 can be bonded together with the adhesive 7a and then fixed together in the grip portion 9. By gripping the grip portion 9 and operating the connector 4, It becomes easier to relatively retract the outer sheath 31 .
Alternatively, the pusher 6 and the outer tube 8 may be bonded together with an adhesive 7a.

In addition, since the inner sheath 30 is fixed to the metal pipe 7 by caulking as described later, if the metal pipe 7 is adhered or fitted to the grip portion 9, the inner sheath 30 and the grip portion 9 are directly connected. It does not have to be glued or mated.
As will be described later, an outer tube 8 is arranged radially outwardly of the metal pipe 7 so as to overlap therewith.

<Caulking part>
Next, the crimped portions 7b, 7c, 7d and 7e will be described mainly with reference to FIG. 5 in addition to FIGS. FIG. 5 is a cross-sectional view showing cross sections of the inner sheath 30 and the metal pipe 7. As shown in FIG. 5, illustration of the outer tube 8, the pusher 6, and the outer sheath 31 is omitted.

It is difficult to evenly apply the adhesive 7a over the entire length between the inner sheath 30 and the metal pipe 7 . This is because if an attempt is made to bond the metal pipe 7 through the inner sheath 30 having the adhesive 7a applied around its perimeter, the adhesive 7a is locally biased due to friction.
Therefore, crimped portions 7b, 7c, 7d, and 7e are provided in order to partially increase the fixing strength between the metal pipe 7 and the inner sheath 30 in the axial direction.

Three or more crimped portions 7b, 7c, 7d, and 7e are provided apart from each other in the axial direction of the metal pipe 7. The interval (center-to-center distance) L2 is narrower than the axial interval (center-to-center distance) L1 between the two crimped portions 7b and 7c (or crimped portions 7c and 7d) on the most proximal side.

In this embodiment, the space L1 between the crimped portions 7b and 7c in the axial direction is equal to the space L1 between the crimped portions 7c and 7d in the axial direction, but the configuration is not limited to this.
For example, the interval between the crimped portions 7c and 7d may be narrower than the interval L1 between the crimped portions 7b and 7c in the axial direction.

According to the above configuration, the space L2 between the crimped portions 7d and 7e on the most distal side where the amount of bending of the sheath 3 is relatively large is relatively larger than the space L1 between the crimped portions 7b and 7c on the most proximal side. By narrowing, the load applied to the crimped portions 7d and 7e can be dispersed, and a large load can be suppressed from being applied to the crimped portions 7d (and 7e) on the leading end side.

As shown in FIG. 3, the surface of the metal pipe 7 has satin-finished surface-treated portions 7f at positions overlapping the crimped portions 7b, 7c, 7d, and 7e.
In this embodiment, the pear-skin-like surface-treated portion 7f is provided to the position of the crimped portions 7b, 7c, 7d, and 7e and to the tip side (distal side) of the crimped portions 7b, 7c, 7d, and 7e. there is

The pear-skin-like surface-treated portion 7f may be formed by sandblasting or the like to finely corrugate the surface, or may be formed by sparsely fixing another member such as an adhesive. It's okay.
Further, the adhesive in this case is only for surface treatment of the metal pipe 7, and is not shown, and is different from the adhesive 7a for bonding the metal pipe 7 and the outer tube 8 described above. be.
On the other hand, the pear-skin-like surface-treated portion 7f is not formed at the distal end of the metal pipe 7 from the crimped portion 7e.

According to the above configuration, the surface-treated portion 7f can increase the frictional force between the metal pipe 7 and the outer tube 8 on the surface side, so that the sheath 3 (from the inner sheath 30 to the outer sheath 31) is bent. Therefore, when the metal pipe 7 is displaced, it is possible to enhance the interlocking in the bending direction with the outer tube 8 on the surface side of the metal pipe 7 and the pusher 6 on the outer side thereof.

The crimped portions 7b, 7c, 7d, and 7e according to the present embodiment are, as shown in FIG. The outer surface is recessed and the extended inner surface is formed to protrude inward.
By forming the crimped portion 7c in this manner, the metal pipe 7 can be stably fitted to the inner sheath 30 in the circumferential direction. However, it is not limited to such a configuration, and the crimped portions 7b, 7c, 7d, and 7e may be formed at three, five, or the like positions in the circumferential direction of the metal pipe 7. FIG.

In the above-described embodiment, the delivery device 1 is described as one for placing the stent graft 2 in a blood vessel, which is a body canal. For example, it may be indwelled in a respiratory system, a digestive system, or any other organ system (digestive tract, etc.). For example, the delivery device 1 may be used through an endoscope.

It should be noted that the various constituent elements of the delivery device of the present invention do not need to exist individually. that a plurality of constituent elements are formed as one member, that one constituent element is formed of a plurality of members, that a certain constituent element is part of another constituent element, or that a certain constituent element is one It is permissible for a part and a part of another component to overlap, and so on.

The above embodiments include the following technical ideas.
(1)
an inner sheath;
a stent mounted around the inner sheath;
a reinforcing member attached to the outer surface of the inner sheath and arranged proximal to the stent;
a pusher mounted around the inner sheath and the reinforcing member and arranged proximal to the stent;
an outer sheath covering the inner sheath, the stent, and the pusher from the outside in the radial direction;
The reinforcing material is
a metal pipe surrounding the inner sheath;
and a resin tube that surrounds the metal pipe,
The metal pipe has a crimped portion, and the inner sheath and the metal pipe are fixed by the crimped portion,
The stent delivery device, wherein the resin tube is arranged so as to cover the crimped portion.
(2)
Three or more of the crimped portions are provided apart from each other in the axial direction of the metal pipe, and the distance between the two crimped portions on the most distal side in the axial direction is the most proximal side. The stent delivery device according to (1), which is narrower than the space in the axial direction between the two crimped portions.
(3)
The stent delivery device according to (1) or (2), wherein the surface of the metal pipe has a satin-finished surface treatment portion at a position overlapping the crimped portion.
(4)
further comprising a grip portion for fixing the proximal end portions of the reinforcing member, the inner sheath and the pusher;
The inner sheath and the metal pipe are adhered to each other with an adhesive inside the holding portion,
The stent delivery according to any one of (1) to (3), wherein the crimped portion is arranged outside the grip portion on the distal side, and the crimped portion is not provided with the adhesive. Device.

1 Delivery device (stent delivery device)
2 Stent graft (stent)
2a stent portion 2b graft portion 3 sheath 4 connector 5 distal tip 6 pusher 7 metal pipe (reinforcing material)
7a Adhesive 7b, 7c, 7d, 7e Crimped portion 7f Surface treatment portion 8 Outer tube (reinforcing material, resin tube)
9 grasping part 30 inner sheath 31 outer sheath 34 guide wire 40 aortic aneurysm 50 aortic arch

Claims (4)

an inner sheath;
a stent mounted around the inner sheath;
a reinforcing member attached to the outer surface of the inner sheath and arranged proximal to the stent;
a pusher mounted around the inner sheath and the reinforcing member and arranged proximal to the stent;
an outer sheath covering the inner sheath, the stent, and the pusher from the outside in the radial direction;
The reinforcing material is
a metal pipe surrounding the inner sheath;
and a resin tube that surrounds the metal pipe,
The metal pipe has a crimped portion, and the inner sheath and the metal pipe are fixed by the crimped portion,
The stent delivery device, wherein the resin tube is arranged so as to cover the crimped portion. Three or more of the crimped portions are provided apart from each other in the axial direction of the metal pipe, and the distance between the two crimped portions on the most distal side in the axial direction is the most proximal side. 2. The stent delivery device according to claim 1, wherein the gap in the axial direction between the two crimped parts is narrower. 3. The stent delivery device according to claim 1, wherein the surface of the metal pipe has a satin-finished surface treatment portion at a position overlapping the crimped portion. further comprising a grip portion for fixing the proximal end portions of the reinforcing member, the inner sheath and the pusher;
The inner sheath and the metal pipe are adhered to each other with an adhesive inside the holding portion,
4. The stent delivery device according to any one of claims 1 to 3, wherein the crimped portion is arranged on the outside on the distal side of the grip portion, and the crimped portion is not provided with the adhesive.

Images