JP2024019113A - Stent set and stent transportation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a stent transportation device which is highly versatile and capable of suitably detaining a stent; and a stent set.

SOLUTION: A stent transportation device includes: a stent; and a sheath for transportation transporting the stent into a body. The stent is composed of a first stent 3 and a second stent 4. The first stent 3 has a sleeve formed of a resin film. The sheath for transportation has a first support part 6a on a distal side supporting the first stent 3; and a second support part 6b provided on a proximal side of the first support part 6a and supporting the second stent 4. The first stent 3 and the second stent 4 can be deployed independently in the aortic arch. A self-expanding force of an intermediate part in an axial center direction in the second stent 4 is greater than a self-expanding force of the sleeve in the first stent 3.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2024,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a stent set that is placed in a biological duct, and a stent transport device for transporting the stent set.

Stents and the like are examples of indwelling devices that are placed in the body for medical purposes. Stents include stent-grafts, which have resin membranes (also called grafts) made of silicone resin or expanded polytetrafluoroethylene, and are used in body vessels such as the gastrointestinal tract (stomach, duodenum, large intestine, etc.) and blood vessels (aortic arch, etc.). There are some that exhibit self-expanding power when placed, suppress cell infiltration, and can be expected to suppress occlusion for a long period of time.
These stents are delivered to a desired location, such as a lesion within a body canal, by a delivery device.

Patent Document 1 discloses a stent graft that includes a resin membrane (graft) and a support stent that supports expansion of the resin membrane. At least one end of the support stent is secured to the graft.

JP 2014-443 Publication

A stent (stent graft) having a resin film as described in Patent Document 1 is thicker than a stent without a resin film (bare stent), so the sheath (outer sheath) that accommodates the stent is thicker than a stent without a resin film (bare stent). A relatively large inner diameter is required. For this reason, the endoscopes that can be passed through the sheath may be limited, reducing versatility.

If the inner diameter of the sheath is made small to narrow the space in which the stent is accommodated, the stent may get caught in the sheath when the stent is exposed from the sheath, increasing the resistance to release the stent. In particular, as the diameter of the stent becomes smaller, the expansion force of the stent becomes higher, and the increase in the release resistance of the stent becomes more significant. In this case, it may be difficult to deploy the stent at a desired position (decreased success rate of reaching the lesion).

The present invention has been made in view of the above problems, and an object of the present invention is to provide a stent transport device and a stent set that are highly versatile and capable of suitably indwelling a stent.

A stent delivery device of the present invention includes a stent and a delivery sheath for transporting the stent into the body, the stent comprising a first stent and a second stent. The first stent has a sleeve formed of a resin film, and the delivery sheath includes a first support part on a distal side that supports the first stent, and a first support part closer to the first support part. a second support part that is provided on the body lumen and supports the second stent, the first stent and the second stent can be deployed independently within the body lumen; The stent is characterized in that a self-expanding force at an axially intermediate portion thereof is greater than a self-expanding force at the sleeve of the first stent.

The stent set of the present invention includes a first stent and a second stent, the first stent having a sleeve formed of a resin film, and the stent set having a sleeve formed of a resin film, The self-expanding force of the first stent is larger than the self-expanding force of the sleeve of the first stent.

According to the present invention, it is possible to provide a stent transport device and a stent set that have high versatility and can suitably indwell a stent.

FIG. 2 is a schematic diagram showing a state in which a stent is placed in an aortic aneurysm portion of an aortic arch using the stent delivery device according to the present embodiment. FIG. 3 is a diagram schematically showing a first stent. FIG. 3 is a diagram schematically showing a second stent. FIG. 3 is a diagram schematically showing a stent set (a first stent and a second stent). FIG. 3 is a diagram schematically illustrating the arrangement of a first stent and a second stent in the inner sheath. It is a figure which shows typically the 1st stent containing a twist prevention wire. It is a figure which shows typically the 2nd stent based on the 1st modification. It is a figure which shows typically the 1st stent based on a 2nd modification. FIG. 3 is an enlarged view of a portion corresponding to section IX in FIG. 2, in which (a) is a diagram showing an end of a sleeve according to a third modification, and (b) is a diagram showing an end of a sleeve according to a fourth modification. It is a figure which shows an edge part. It is a figure showing typically a 1st stent concerning a 2nd modification, and a 2nd stent concerning a 5th modification. It is a figure which shows typically the edge part of the 2nd stent based on a 6th modification. It is a figure which shows typically the edge part of the stent set in the state where the 2nd stent based on the 6th modification was accommodated in the 1st stent. It is a figure which shows typically the edge part of the 2nd stent based on the 7th modification.

Hereinafter, a stent transport device 1 and a stent set S according to an embodiment of the present invention will be described using the drawings.
Note that the embodiments described below are merely examples for facilitating understanding of the present invention, and do not limit the present invention. That is, the shapes, dimensions, arrangement, etc. of the members described below may be changed and improved without departing from the spirit of the present invention, and it goes without saying that the present invention includes equivalents thereof.

Further, the drawings used in this embodiment illustrate the configuration and shape of the stent delivery device and stent set of the present invention, and the arrangement of each member (each part) constituting the stent delivery device and stent set. It is not limited to. Additionally, the drawings do not necessarily accurately depict dimensional ratios such as length, width, and height of the stent delivery device and stent set.
Note that the proximal side (base end side) refers to the side placed near the operator during treatment, and the distal side (tip side) refers to the side placed far from the operator during treatment.
In addition, in all the drawings, similar components are given the same reference numerals, and overlapping explanations will be omitted as appropriate.

<Summary>
First, an overview of the stent delivery device of the present invention will be described using a stent delivery device 1 according to an embodiment as an example with reference to FIGS. 1 to 5.
FIG. 1 is a schematic diagram showing a state in which a stent 2 is placed in an aortic aneurysm 55 portion of an aortic arch 50 using a stent delivery device 1 according to the present embodiment. FIG. 2 is a diagram schematically showing the first stent 3, and FIG. 3 is a diagram schematically showing the second stent 4.
FIG. 4 schematically shows the stent set S (first stent 3 and second stent 4), and FIG. 5 schematically illustrates the arrangement of the first stent 3 and second stent 4 in the inner sheath 6. It is a diagram.
In the inner sheath 6 of FIG. 1, illustration of a large diameter portion 6d shown in FIG. 5 and described later is omitted.

A stent delivery device 1 according to an embodiment of the present invention includes a stent 2 and a delivery sheath 5 that transports the stent 2 into the body.
The stent 2 includes a first stent 3 and a second stent 4. As shown in FIG. 2, the first stent 3 has a sleeve 3a made of a resin film. As shown in FIG. 5, the transport sheath 5 includes a distal first support portion 6a that supports the first stent 3, and a distal first support portion 6a that supports the second stent 4. The first stent 3 and the second stent 4 can be independently deployed within the body lumen (aortic arch 50 shown in FIG. 1).
The self-expanding force (elastic restoring force) of the axially intermediate portion 4a of the second stent 4 is larger than the self-expanding force of the sleeve 3a of the first stent 3.

In other words, the stent delivery device 1 is configured to be able to support the first stent 3 and the second stent 4 at shifted positions and to deploy them independently. The first support part 6a and the second support part 6b are parts located between the inner sheath 6 and the outer sheath 7 in the radial direction when the stent is transported. For example, the first stent 3 and the second stent 4 are fixed to the inner sheath 6 with a suture thread (not shown), so that the first stent 3 and the second stent 6 can be fixed to each other. 4 may be supported.

According to the above configuration, the first stent 3 and the second stent 4 are not overlapped during transportation, compared to a case where the first stent 3 and the second stent 4 are overlapped during transportation and are formed thickly. By doing so, it is possible to suppress the expansion of the first stent 3 and the second stent 4 in the outer radial direction within the accommodation space of the stent 2.

Therefore, even if the sleeve 3a formed of a resin film is made thicker, the filling rate of the stent 2 (the first stent 3 and the second stent 4) can be lowered. Therefore, the thickness of the sleeve 3a of the first stent 3 can be ensured, and the strength can be increased, and the filling rate of the stent 2 can be lowered, so that the stent 2 can be placed in a suitable manner.

Here, the term "filling rate" refers to the proportion of the stent 2 in the cross section of the accommodation space for the stent 2 provided in the delivery sheath 5.
For example, in the case of a cover/stent integrally molded product with a filling rate of about 80%, the thickness of the cover (sleeve 3a) is limited to about 10 μm or less. At the same filling rate as in this case, when the first stent 3 and the second stent 4 were not overlapped during transportation, the thickness of the sleeve 3a could be made approximately 37 μm. Therefore, it becomes possible to indwell the stent 2 in the body while maintaining its function for a long period of time.

On the other hand, for example, when comparing the case where the thickness of the cover (sleeve 3a) is about 50 μm, the filling rate can be lowered from about 80% to about 20% compared to a cover/stent integrally molded product. Therefore, the outer sheath 7 (transport sheath 5) that covers the stent 2 can be made small in diameter, and the transport sheath 5 can be easily passed through a narrow body canal or an endoscope, thereby increasing versatility.

The stent set S according to this embodiment includes a first stent 3 and a second stent 4.
The first stent 3 has a sleeve 3a formed of a resin film, and the self-expanding force of the axially intermediate portion of the second stent 4 is greater than the self-expanding force of the sleeve 3a of the first stent 3. It is characterized by being large.

According to the above configuration, the self-expanding force of the axially intermediate portion 4a of the second stent 4 is larger than the self-expanding force of the sleeve 3a of the first stent 3, so that the inner side of the first stent 3 By arranging the second stent 4 and expanding the second stent 4, the expansion force of the intermediate portion 4a of the second stent 4 can compensate for the expansion of the sleeve 3a of the first stent 3.

<Overall configuration>
Next, the overall configuration of the stent delivery device 1 will be described with reference mainly to FIGS. 1 and 5.
The stent delivery device 1 according to the present embodiment is used to transport the stent 2 into a blood vessel in order to place the stent 2 in an aortic aneurysm 55 of an aortic arch 50.
The stent delivery device 1 only needs to be able to transport the stent 2, and is not limited to being used for such a site. For example, the stent delivery device 1 may be used in the gastrointestinal tract (stomach, duodenum, large intestine, etc.).
Further, the stent transport device 1 (transport sheath 5) may be passed through an endoscope as described above.

The stent delivery device 1 includes a stent 2 and a delivery sheath 5 that transports the stent 2.
The stent 2 (denoted as stent set S in FIG. 4) includes a first stent 3 and a second stent 4 deployed radially inside the first stent 3.
The transport sheath 5 includes an inner sheath 6 to which the stent 2 is attached, and an outer sheath 7 that covers the outer periphery of the stent 2 during transport.

As shown in FIG. 5, the inner sheath 6 includes a narrow diameter part 6c that becomes the first support part 6a that supports the first stent 3, and a large diameter part 6d that becomes the second support part 6b that supports the second stent 4. and. Further, a distal tip 12 (see FIG. 1) is attached to the distal end of the inner sheath 6.

As will be described later, the first stent 3 has a portion having a flared portion 3c and having a different size in the radial direction compared to the second stent 4 formed in a straight cylindrical shape. For this reason, when the first stent 3 is housed between the inner sheath 6 and the outer sheath 7 in a reduced diameter state, the bulk increases first from the flared portion 3c.
In this respect, the first stent 3 is supported by the narrow diameter part 6c which becomes the first support part 6a, and the second stent 4 is supported by the large diameter part 6d which becomes the second support part 6b. , the first stent 3 and the second stent 4 can be suitably supported within the outer sheath 7.
In other words, the bulky portion can be accommodated in the relatively wide space between the narrow diameter portion 6c and the outer sheath 7.

<First stent>
The first stent 3 includes a sleeve 3a formed of a resin film as described above, and a naturally expandable stent connected to at least one of the distal side or the proximal side (both sides in this embodiment) of the sleeve 3a. A locking portion (anchor 3b) that can be locked to a dovetail biological tube (aortic arch 50) is provided.

The "locking part" according to this embodiment is made of a metal wire that has a higher expansion force (elastic restoring force) than the resin sleeve 3a. Note that the anchor 3b as the "locking part" is not limited to being made of metal wire, but may be made of something laser cut from a pipe or made of resin that is decomposed and absorbed in the living body. Good too. The same applies to what constitutes the second stent 4 (14), which will be described later.
The anchor 3b as a locking portion according to this embodiment is made up of a plurality of intertwined wires.
In this document, "entanglement" includes a state in which a plurality of wires are stacked one on top of the other in contact and intersect, and a state in which a plurality of wires are folded back into a hook shape and intersect.
However, the present invention is not limited to such a configuration, and the anchor 3b may have a configuration in which one wire is repeatedly folded back and overlapped.

According to the above configuration, since the first stent 3 is provided with the locking portion (anchor 3b), the first stent 3 can be suitably locked in the biological tube (aortic arch 50), and the second stent 4 can be can be deployed from inside the first stent 3.

The self-expanding force of the anchor 3b formed by intertwining a plurality of wires is higher than the self-expanding force of the resin sleeve 3a and the self-expanding force of the twist prevention wire 10 described later.
By forming the anchor 3b in this manner, the connecting portion 3e connected to the anchor 3b in the sleeve 3a can be expanded.
That is, since the cross section of the anchor 3b in the expanded state is formed into a cylindrical shape, the cross section of the connecting portion 3e also expands into a cylindrical shape.

The anchor 3b has a connecting portion 3e that connects to the sleeve 3a, and the diameter increases from the connecting portion 3e toward the open end side. The connecting portion 3e according to this embodiment shows the boundary between the sleeve 3a and the anchor 3b in FIG. 2, but if the wire is configured to overlap the sleeve 3a, it refers to the area where the wire overlaps.
The sleeve 3a according to this embodiment has an outer diameter of 22 mm, a thickness of 0.050 to 0.120 mm, and is made of silicone resin.

Locking portions (anchors 3b) are provided at both ends of the sleeve 3a. In the sleeve 3a, the axial length of the region where the anchor 3b is not provided is longer than the axial length of the region where the anchor 3b is provided.

Note that the above-mentioned "length in the axial direction of the region where the anchor 3b is provided in the sleeve 3a" includes zero.
According to the above configuration, the first stent 3 can be locked to the biological tube (aortic arch 50) using the locking portion (anchor 3b), which is preferable. However, the sleeve 3a may have a structure in which the locking portion (anchor 3b) that can naturally expand is not formed and the sleeve 3a is formed in a straight cylindrical shape.

As shown in FIG. 2, the anchor 3b of the first stent 3 has a first flare part (flare part 3c) whose diameter increases toward the distal end, and a distal end part 3d that extends in a straight cylinder shape beyond the flare part 3c. , is provided.
The distal end portion 3d has a diameter expansion degree lower than that of the flare portion 3c (and the flare portion 14c of the second stent 14 described later).

"Degree of diameter expansion" refers to the degree of inclination angle with respect to an axis (not shown) in side view, and includes zero. In other words, the distal end portion 3d shown in FIG. 2, which is formed into a straight cylinder, has a diameter expansion degree lower than that of the flare portion 3c (and the flare portion 14c of the second stent 14, which will be described later).

Note that the distal end portion 3d that extends in a straight cylindrical shape does not necessarily have to be provided, and may have a diameter that expands more gently than the flared portion 3c.
However, the configuration is not limited to this, and a configuration in which the flare portion 3c is formed up to the end may be used.

<Second stent>
The second stent 4 according to the present embodiment is a so-called bare stent formed of intertwined metal wires, and is formed by intertwining a plurality of wires, and is formed into a cylindrical shape extending in the axial direction. .

The second stent 4 has a cylindrical portion 4b extending in the axial direction at an axially intermediate portion. The length of the cylindrical portion 4b is equal to or longer than the total length of the sleeve 3a.
The above-mentioned "extending to the axially intermediate portion" means extending at least to the axially intermediate portion, and as in the second stent 4 according to the present embodiment shown in FIG. , a cylindrical portion 4b may be provided throughout.
On the other hand, as shown in FIG. 7 and described later, the flared portion 14c provided at the end rather than the axially intermediate portion is of course included in the cylindrical portion 4b (cylindrical portion 14b). Make it not exist.

The above-mentioned "cylindrical part extending in the axial direction" means a cylindrical part that extends including an axial component, and is not limited to a straight cylinder shape, but has a diameter at a position shifted in the axial direction. This also includes items with different sizes in different directions (worm-like items). For example, if a caterpillar-shaped one is used, the sliding of the cylindrical part with respect to the sleeve can be suppressed.
According to the above configuration, the resin sleeve 3a, which has a weak diameter expansion force, can be expanded over its entire length due to the cylindrical portion 4b having a length equal to or longer than the entire length of the sleeve 3a.

<Detention method>
A method for placing the stent 2 using the stent delivery device 1 will be described.
First, the operator inserts the delivery sheath 5 into the blood vessel and places the first stent 3 at a position facing the aortic aneurysm 55. Then, the operator pulls the outer sheath 7 toward the proximal side with respect to the inner sheath 6 to release the attachment state of the first stent 3 to the first support portion 6a. The first stent 3 exposed from the outer sheath 7 self-expands and is placed in a site where it contacts the aortic aneurysm 55 within the body canal (aortic arch 50).

Next, the operator further inserts the transport sheath 5 and arranges the second support part 6b inside the indwelled first stent 3. Then, the operator further pulls the outer sheath 7 toward the proximal side with respect to the inner sheath 6 to release the attachment state of the second stent 4 to the second support portion 6b. The second stent 4 exposed from the outer sheath 7 can self-expand and push out the resin sleeve 3a of the first stent 3, thereby assisting the expansion force. That is, according to such a method, the resin sleeve 3a, which does not easily generate expansion force (elastic restoring force in the radial expansion direction), can be expanded over the entire length of the aortic aneurysm 55 in the aortic arch 50.

For example, as a method for releasing the attached state of the first stent 3 from the first support part 6a and a method of releasing the attached state of the second stent 4 from the second support part 6b, by pulling a trigger wire (not shown), This is done by cutting a suture (not shown) attached to a trigger wire that binds the openings of the first stent 3 and the second stent 4 and ties them to the inner sheath 6.

<Twist prevention part>
Next, the torsion prevention portion (torsion prevention wire 10) provided in the first stent 3 will be explained with reference to FIG. 6. FIG. 6 is a diagram schematically showing the first stent 3 including the anti-twist wire 10.

The sleeve 3a may be provided with a twist prevention portion (torsion prevention wire 10) extending in the axial direction.
The twist prevention wire 10 in this embodiment is for preventing the sleeve 3a from being twisted, is made of metal such as nickel-titanium alloy, and is embedded in the resin sleeve 3a.

However, the present invention is not limited to such a configuration, and the twist prevention portion may be provided along the inner or outer surface of the sleeve 3a, or may be provided exposed from the sleeve 3a.

Moreover, the above-mentioned "extending in the axial direction" specifically means extending including an axial direction component. Although one twist prevention wire 10 according to the present embodiment is passed through the sleeve 3a in the axial direction, the structure is not limited to this. In other words, in addition to the straight line shown in FIG. 6, this includes a spiral line.

Note that the twist prevention portion is not limited to the solid metal twist prevention wire 10, and may be made of resin or hollow. Furthermore, a plurality of twist prevention wires 10 may be provided in the circumferential direction of the first stent 3.
In particular, when the torsion prevention part is composed of a plurality of wires, it is preferable that the wires extend in parallel or are not intertwined, since the thickness of the first stent 3 can be reduced.

According to the above configuration, twisting deformation of the sleeve 3a, which is easily deformed due to being formed of a resin film, can be suitably prevented, and the first stent 3 can be suitably expanded. In other words, it is possible to prevent the inner diameter of the sleeve 3a from narrowing and the space for the second stent 4 to pass to disappear.

<First modification example>
In the above embodiment, the second stent 4 is described as having a straight cylindrical shape, but the second stent 4 is not limited to such a configuration.
Next, the second stent 14 composed of a plurality of parts according to a first modification will be explained with reference mainly to FIG. 7. FIG. 7 is a diagram schematically showing the second stent 14 according to the first modification.

The second stent 14 according to the first modification is configured to be divided into a plurality of parts (a proximal part 15 and a distal part 16) in the axial direction.
In this embodiment, the second stent 14 is composed of two parts, the proximal part 15 and the distal part 16, which are symmetrical in plane, but the structure is not limited to this. For example, the second stent 14 only needs to be able to spread the first stent 3 outward in the radial direction, and the second stent 14 is not limited to a plane-symmetrical shape, but may be formed of an irregularly shaped part. Moreover, it may be further comprised of a plurality of parts. For example, the configuration may further include a cylindrical component provided between the proximal component 15 and the distal component 16.

According to the above configuration, the position of the second stent 14 is prevented from being biased toward one side of the first stent 3, and is adjusted to match the positions of the distal and proximal ends of the first stent 3. Easier to place. The overall length of the second stent 14 can be adjusted at the position where the proximal part 15 and the distal part 16 of the second stent 14 are deployed.

For example, when placing the stent set S (first stent 3 and second stent 14) in a bent body canal, the stent set S (first stent 3 and second stent 14) is placed at a suitable position corresponding to the length of the first stent 3 placed in the bent state. Two stents 14 (proximal component 15 and distal component 16) can be deployed.

Further, the second stent 14 is provided with a flared portion 14c whose diameter increases toward the distal end. The opening diameter of the flare portion 14c is larger than the opening diameter of the first stent 3.
Note that the flare portion 14c is not limited to the second stent 14 that is divided into a plurality of parts, and may be provided in the second stent 4 that is not divided into a plurality of parts as shown in FIG.

According to the above configuration, by engaging the flare portion 14c of the second stent 14 with the opening of the first stent 3, contents (fluid) accumulate between the first stent 3 and the second stent 14. can be suppressed.

The second stent 14 according to the first modification has a cylindrical portion 14b (in this example, straight cylindrical) extending in the axial direction at an intermediate portion in the axial direction as a whole. The length of the cylindrical portion 14b is longer than the entire length of the sleeve 3a. However, the configuration is not limited to this, and the length of the cylindrical portion 14b and the total length of the sleeve 3a may be the same length.

As described above, in the second stent 14 that is composed of multiple parts, the length of the cylindrical part 14b is equal to the length of the cylindrical part 14b of each part (proximal part 15 and distal part 16). Let be the total length.
That is, the total length in the axial direction of the cylindrical portion 14b of the proximal part 15 and the distal part 16 is equal to or longer than the total length of the sleeve 3a. When the length of the cylindrical part 14b of the second stent 14 is longer than the full length of the sleeve 3a, the cylindrical parts 14b of the proximal part 15 and the distal part 16 are overlapped and placed. The Rukoto.

As described above, the degree of diameter expansion of the distal end portion 3d of the first stent 3 is formed to be lower than the degree of diameter expansion of the flared portion 14c. Therefore, a load in the diametrical expansion direction is easily applied from the flared portion 14c to the distal end portion 3d of the first stent 3, and the two are more likely to engage with each other.

The axial length of the second flare portion (flare portion 14c) is preferably greater than or equal to the axial length of the flare portion 3c.
According to the above configuration, since the second flare part (flare part 14c) has a long axial length, it becomes easy to cover the first flare part (flare part 3c) from the inside, and the flare part 3c and the flare part 14c can be easily covered from the inside. It is possible to suppress the contents (fluid) from accumulating between the two.

The second flare portion (flare portion 14c) is preferably provided on a component located at the distal end of the plurality of components. In this example, the flare portions 14c are provided at both ends of the second stent 14, as shown in FIG.

As described above, by providing at least the part (distal part 16) at the distal end of the second stent 14, the flare part 14c of the second stent 14 can be replaced with the flare part 3c of the first stent 3. The parts on the proximal side of the second stent 14 can be positioned to match the position of the proximal end of the first stent 3 while being engaged on the inside.

In particular, in this embodiment, the second stent 14 is provided with flared portions 14c at both the proximal and distal ends.
The second stent 14 can be placed at a position where the flare part 14c of the distal component 16 overlaps the flare part 3c on the distal side of the first stent 3 previously placed in the aortic arch 50. Then, the distal component 16 of the second stent 14 is deployed.
Next, the inner sheath 6 is pushed forward, and at a position where the flare portion 14c of the proximal component 15 overlaps the flare portion 3c on the proximal side of the first stent 3, the outer sheath 7 is further retracted and the second stent 14 The proximal part 15 of the is expanded. At this time, in this embodiment, the cylindrical portions 14b of the proximal component 15 and the distal component 16 are placed in an overlapping manner.

In this way, the flared portion 3c on the distal side of the first stent 3, the flared portion 14c of the distal side component 16 constituting the second stent 14, and the flared portion 3c on the proximal side of the first stent 3. By aligning the positions of the flare portion 14c of the proximal part 15 constituting the second stent 14, the first stent 3 and the second stent 14 are suitably engaged.

<Second modification example>
In the embodiment described above, the sleeve 3a of the first stent 3 has been described as being formed in a straight cylinder shape, but the present invention is not limited to such a configuration.
Next, a first stent 8 having an enlarged diameter portion 8f according to a second modification will be described with reference mainly to FIG. 8. FIG. 8 is a diagram schematically showing a first stent 8 according to a second modification.

The sleeve 3a of the first stent 8 according to the second modification has an enlarged diameter portion 8f extending radially outward from the vicinity in the axial direction over the entire circumference.
As shown in FIG. 8, the enlarged diameter portion 8f according to the present example is formed with an inclination of 5 degrees to 15 degrees with respect to an axis (not shown) in side view, and has an angular mountain shape (triangular shape). It is a bulge. However, the enlarged diameter portion 8f is not limited to such a shape, and may be formed in a rounded shape. Furthermore, the shape of the enlarged diameter portion 8f is not limited as long as it protrudes radially outward from its vicinity in the axial direction; You can.

According to the above configuration, the enlarged diameter portion 8f, which is a part of the sleeve 3a formed of a resin film, protrudes radially outward, so that the sleeve 3a is held against the inner wall of a body canal such as a blood vessel or digestive tract into which it is inserted. Sealing performance (adhesion) can be improved.
Specifically, when the first stent 8 expands within the body canal, the enlarged diameter portion 8f that can be elastically restored in the radial direction is pressed against the inner wall of the body canal and deformed, and the elastic restoring force in the radial direction is increased. By adding it, it becomes possible to make close contact with the inner wall of the body canal.
Therefore, it is possible to suppress blood and digested substances from passing (leaking) between the first stent 8 and the inner wall of the body canal.

<Third and fourth variations>
In the first stent 3 in the above embodiment, as shown in FIG. 2, the end (edge) of the sleeve 3a was formed to extend linearly around the radial direction. but not limited to.
Next, the end portion 8g of the sleeve 3a according to the third and fourth modified examples will be explained with reference mainly to FIG. 9. FIG. 9 is an enlarged view of a portion corresponding to section IX in FIG. 2, and FIG. 9(a) is a view showing an end portion 8g of a sleeve 3a according to a third modification, and FIG. 9(b) This is a diagram showing an end portion 8g of a sleeve 3a according to a fourth modification.

As shown in FIG. 9(a), the locking portion (anchor 3b) according to this example has a mesh 30 in which a plurality of wires are intertwined, and the end portion 8g of the sleeve 3a connected to the anchor 3b is , are formed in a zigzag pattern along the mesh 30 of the anchor 3b (which constitutes the wire located on the proximal end side in the axial direction in the anchor 3b).
In other words, the end portion 8g of the sleeve 3a constitutes the mesh 30 of the anchor 3b, and is formed in a zigzag pattern (to form a plurality of consecutive peaks) along the wire that circulates while swinging in the axial direction.

The above phrase "the end 8g of the sleeve 3a is formed along the mesh 30" means that the end 8g of the sleeve 3a is completely aligned with the wire of the mesh 30 when viewed from the side. The wire diameter is not limited to match the mesh 30, but it means that the wire diameter is within five times the wire diameter of the wire constituting the mesh 30.
According to the above configuration, since the end portion 8g of the sleeve 3a is formed in a zigzag pattern along the mesh 30 of the anchor 3b, a floating (gap) is not generated between the end portion 8g of the sleeve 3a and the mesh 30. During this time, it is possible to prevent blood and digested substances from entering.

In the third modification shown in FIG. 9(a) above, an example was described in which the end portion 8g of the sleeve 3a is formed in a zigzag pattern along the wire on the proximal end side in the axial direction, which constitutes the mesh 30. However, the present invention is not limited to such a configuration.

For example, as shown in FIG. 9(b), when there are wires in the first row 30a and the second row 30b from the proximal end side of the anchor 3b as components of the mesh 30, the end portion 8g of the sleeve 3a is It may be formed in a zigzag pattern along the second row 30b of the mesh 30 of the anchor 3b.

In this way, the end portion 8g of the sleeve 3a is formed along the second row 30b and subsequent rows (that is, the tip side) of the mesh 30 of the anchor 3b, thereby increasing the connection strength between the sleeve 3a and the anchor 3b. It can be made higher.
Furthermore, the end portion 8g of the sleeve 3a may be formed along the meshes 30 (the wires forming the meshes 30), and may be formed over multiple rows of the meshes 30.

<Fifth modification example>
Although the second stent 4 according to the embodiment shown and described in FIG. 3 was formed into a straight cylinder, the present invention is not limited to such a configuration.
Next, a second stent 9 according to a fifth modification example that can be suitably biased against the first stent 8 will be described with reference mainly to FIG. 10. FIG. 10 is a diagram schematically showing a first stent 8 according to a second modification and a second stent 9 according to a fifth modification.

The second stent 9 according to this example has a biasing portion 9c that has a larger self-expanding force than the vicinity in the axial direction, and the biasing portion 9c disposes the second stent 9 inside the first stent 8. It is provided at a position facing the enlarged diameter portion 8f in the indwelling state in which it is indwelled in the body.
Regarding the biasing portion 9c and the second enlarged diameter portion 9d, which will be described later, it is sufficient that the enlarged diameter portion 8f can be biased from the inside, so in addition to being formed over the entire circumference, they may be formed intermittently at multiple locations. Including those who are present.

Note that the "biasing part" is not limited to a part that is formed to protrude outward in the radial direction from the vicinity in the axial direction, such as a second enlarged diameter part 9d described later, but also a part that has a large elastic restoring force. The expansion force may be increased depending on the material and structure.
According to the above configuration, since the second stent 9 is provided with the biasing portion 9c, a load is applied to the opposing enlarged diameter portion 8f in the diameter expansion direction, so that the enlarged diameter portion 8f moves toward the body canal. It can assist in adhering to the inner wall.

In this example, the enlarged diameter part 8f is a first enlarged diameter part, and the second stent 9 has a second enlarged diameter part 9d as a biasing part 9c that protrudes outward in the radial direction from the vicinity in the axial direction. have The second enlarged diameter portion 9d is provided at a position opposite to the enlarged diameter portion 8f in an indwelling state in which the second stent 9 is disposed inside the first stent 8 and indwelled in the body.
Further, it is preferable that the second enlarged diameter portion 9d (the outer shape of the second enlarged diameter portion 9d) has the same or similar shape to the enlarged diameter portion 8f (the inner shape of the second enlarged diameter portion 9d) because it can bias the enlarged diameter portion 8f evenly. However, the structure is not limited to this, and it is sufficient that the structure protrudes outward in the radial direction from the vicinity in the axial direction.

According to the above configuration, since the second stent 9 is provided with the second enlarged diameter portion 9d, a load is applied to the opposing enlarged diameter portion 8f in the diameter expansion direction, and the enlarged diameter portion 8f is It can assist in adhering closely to the inner wall of the tube.

<Sixth and seventh variations>
Although the above embodiment does not mention that the second stents 4, 9, and 14 have different mesh sizes, they may have different mesh sizes.
Regarding this point, the second stent 11 according to a sixth modification will be described with reference to FIGS. 11 and 12, and the second stent 13 according to a seventh modification will be described with reference to FIG. 13.
In addition, in FIG. 12, the anchor 3b of the first stent 3 whose diameter is expanded in the radial direction is shown in a straight cylinder shape. The anchor 3b may have a straight cylindrical shape, or may have a flared portion 3c having a diameter larger than other portions as in the above embodiment.

FIG. 11 is a diagram schematically showing an end portion of the second stent 11 according to the sixth modification, and FIG. 12 is a diagram showing the stent in a state where the second stent 11 according to the sixth modification is accommodated in the first stent 3. It is a figure which shows the edge part of a set typically. FIG. 13 is a diagram schematically showing an end portion of the second stent 13 according to the seventh modification.

The second stent 11 shown in FIG. 11 has a mesh 40 in which a plurality of wires are intertwined. The mesh 40 has a fine mesh part 40a with small meshes and a coarse mesh part 40b with large meshes. The narrow portion 40a is provided at a position facing the end of the sleeve 3a in an indwelling state in which the second stent 11 is disposed inside the first stent 3 and indwelled in the body as shown in FIG. 12. The outer diameter of the narrow portion 40a is larger than the inner diameter of the end of the sleeve 3a in its natural state.
The "position facing the end of the sleeve 3a" specifically refers to a position overlapping the edge of the end of the sleeve 3a.

According to the above configuration, the narrow part 40a of the mesh of the second stent 11 expands the end of the sleeve 3a of the first stent from the inside, thereby suppressing the end of the sleeve 3a from entering into the mesh. This makes it possible to suppress the formation of wrinkles at the end of the sleeve 3a that would impede the adhesion to the inner wall of the body canal.

In the second stent 11 according to this example, the narrow portions 40a are provided at the ends (both ends) of the second stent 11.
However, it is only necessary that the narrow part 40a be disposed at a position facing the end of the sleeve 3a.
The second stent 13 according to the seventh modification includes a coarse part 40b on the center side of the second stent 13, a fine part 40a on the end side of the coarse part 40b and opposite to the end of the sleeve 3a. A coarse portion 40c is provided at an end portion beyond the fine portion 40a.

According to the second stent 13, the range of the narrow portion 40a, which requires a lot of effort to manufacture, can be narrowed, so that manufacturing costs can be kept low.

Note that the various components related to the stent delivery device 1 and the stent set S of the present invention do not need to exist independently. A plurality of components are formed as a single member, a component is formed of a plurality of members, a component is a part of another component, and a component is a single component. It is allowed that a portion of a component overlaps with a portion of another component, etc.

The above embodiment includes the following technical ideas.
(1)
A stent delivery device comprising a stent and a delivery sheath for transporting the stent into the body,
The stent is composed of a first stent and a second stent,
The first stent has a sleeve made of a resin film,
The delivery sheath includes a first support part on a distal side that supports the first stent, and a second support part that is provided on a proximal side of the first support part and supports the second stent. the first stent and the second stent can be independently deployed within a body lumen;
A stent delivery device characterized in that a self-expanding force of an axially intermediate portion of the second stent is greater than a self-expanding force of the sleeve of the first stent.
(2)
The stent delivery device according to (1), wherein the first stent includes a locking portion connected to at least one of the distal side or the proximal side of the sleeve, which can expand naturally and can be locked to a biological tube. .
(3)
The stent delivery device according to (1) or (2), wherein the sleeve has an enlarged diameter portion projecting outward in the radial direction from the vicinity in the axial direction over the entire circumference.
(4)
The second stent has a biasing portion that has a larger self-expanding force than the vicinity in the axial direction,
The stent transport according to (3), wherein the biasing section is provided at a position facing the enlarged diameter section in an indwelling state in which the second stent is disposed inside the first stent and indwelled in the body. device.
(5)
The enlarged diameter part is a first enlarged diameter part,
The second stent has a second enlarged diameter portion that protrudes outward in the radial direction from the vicinity in the axial direction,
The second enlarged diameter portion is provided at a position opposite to the first enlarged diameter portion in an indwelling state in which the second stent is disposed inside the first stent and indwelled in the body (3); The stent delivery device according to (4).
(6)
The locking portion has a mesh in which a plurality of wires are intertwined,
The stent delivery device according to (2), wherein the end portion of the sleeve connected to the locking portion is formed in a zigzag pattern along the mesh of the locking portion.
(7)
The second stent has a network in which a plurality of wires are intertwined,
The mesh has a fine part with small meshes and a coarse part with large meshes,
The narrow portion is provided at a position opposite to the end portion of the sleeve in an indwelling state in which the second stent is disposed inside the first stent and indwelled in the body,
The stent delivery device according to any one of (1) to (6), wherein the outer diameter of the narrow portion is larger than the inner diameter of the end of the sleeve in its natural state.
(8)
The locking portions are provided at both ends of the sleeve,
In the sleeve, the axial length of the region where the locking portion is not provided is longer than the axial length of the region where the locking portion is provided (2) or (6). The described stent delivery device.
(9)
The stent delivery device according to any one of (1) to (8), wherein the sleeve is provided with a twist prevention portion extending in the axial direction.
(10)
The second stent has a cylindrical portion extending in the axial direction at an axially intermediate portion,
The stent delivery device according to any one of (1) to (9), wherein the length of the cylindrical portion is equal to or longer than the total length of the sleeve.
(11)
The stent delivery device according to any one of (1) to (10), wherein the second stent is divided into a plurality of parts in the axial direction.
(12)
The second stent is provided with a flared portion that increases in diameter toward the distal end,
The stent delivery device according to any one of (1) to (11), wherein the flare portion has an opening diameter larger than an opening diameter of the first stent.
(13)
The stent delivery device according to (12), wherein the first stent has a distal end portion whose diameter expansion is lower than the diameter expansion of the flared portion.
(14)
The first stent is provided with a first flare portion whose diameter increases toward the distal end,
The flare part is a second flare part,
The stent delivery device according to (12) or (13), wherein the axial length of the second flare portion is greater than or equal to the axial length of the first flare portion.
(15)
The stent delivery device according to (14), wherein the second flare portion is provided at a distal end portion of the plurality of components.
(16)
Consists of a first stent and a second stent,
The first stent has a sleeve made of a resin film,
A stent set, wherein a self-expanding force of an axially intermediate portion of the second stent is greater than a self-expanding force of the sleeve of the first stent.

1 Stent transport device 2 Stent 3 First stent 3a Sleeve 3b Anchor (locking part)
3c Flare part (first flare part)
3d End portion 3e Connection portion 4 Second stent 4a Intermediate portion 4b Cylindrical portion 5 Transport sheath 6 Inner sheath 6a First support portion 6b Second support portion 6c Narrow diameter portion 6d Large diameter portion 7 Outer sheath 8 First stent 8f Expanded diameter part (first expanded diameter part)
8g End portions 9, 11, 13 Second stent 9c Biasing portion 9d Second enlarged diameter portion 10 Torsion prevention wire 12 Distal tip 14 Second stent 14b Cylindrical portion 14c Flare portion (second flare portion)
30 Mesh 30a 1st row 30b 2nd row 40 Mesh 40a Fine mesh portion 40b, 40c Coarse mesh portion 50 Aortic arch (body lumen, biological tube)
55 Aortic aneurysm S stent set

Claims (16)

A stent delivery device comprising a stent and a delivery sheath for delivering the stent into the body,
The stent is composed of a first stent and a second stent,
The first stent has a sleeve made of a resin film,
The delivery sheath includes a first support part on a distal side that supports the first stent, and a second support part that is provided on a proximal side of the first support part and supports the second stent. wherein the first stent and the second stent are independently deployable within a body lumen;
A stent delivery device, wherein a self-expanding force of an axially intermediate portion of the second stent is greater than a self-expanding force of the sleeve of the first stent. The stent delivery device according to claim 1, wherein the first stent includes a locking portion connected to at least one of a distal side and a proximal side of the sleeve, which can expand naturally and can be locked to a biological tube. . 3. The stent delivery device according to claim 2, wherein the sleeve has an enlarged diameter portion extending radially outward from the vicinity in the axial direction over the entire circumference. The second stent has a biasing portion that has a larger self-expanding force than the vicinity in the axial direction,
The stent conveyor according to claim 3, wherein the biasing section is provided at a position facing the enlarged diameter section in an indwelling state in which the second stent is disposed inside the first stent and indwelled in the body. device. The enlarged diameter part is a first enlarged diameter part,
The second stent has a second enlarged diameter portion that protrudes outward in the radial direction from the vicinity in the axial direction,
5. The second enlarged diameter portion is provided at a position opposite to the first enlarged diameter portion in an indwelling state in which the second stent is disposed inside the first stent and indwelled in the body. The described stent delivery device. The locking portion has a mesh in which a plurality of wires are intertwined,
The stent delivery device according to claim 5, wherein an end of the sleeve connected to the locking portion is formed in a zigzag pattern along the mesh of the locking portion. The second stent has a network in which a plurality of wires are intertwined,
The mesh has a fine part with small meshes and a coarse part with large meshes,
The narrow portion is provided at a position opposite to the end portion of the sleeve in an indwelling state in which the second stent is disposed inside the first stent and indwelled in the body,
The stent delivery device according to claim 6, wherein the outer diameter of the narrow portion is larger than the inner diameter of the end of the sleeve in a natural state. The locking portions are provided at both ends of the sleeve,
The stent transport according to claim 7, wherein, in the sleeve, the length in the axial direction of the region where the locking portion is not provided is longer than the length in the axial center direction of the region where the locking portion is provided. device. The stent delivery device according to claim 8, wherein the sleeve is provided with a twist prevention portion extending in the axial direction. The second stent has a cylindrical portion extending in the axial direction at an axially intermediate portion,
The stent delivery device according to claim 9, wherein the length of the cylindrical portion is equal to or longer than the total length of the sleeve. The stent delivery device according to claim 10, wherein the second stent is divided into a plurality of parts in the axial direction. The second stent is provided with a flared portion that increases in diameter toward the distal end,
The stent delivery device according to claim 11, wherein an opening diameter of the flare portion is larger than an opening diameter of the first stent. 13. The stent delivery device of claim 12, wherein the first stent has a distal end portion with a lower diameter expansion than the flared portion. The first stent is provided with a first flare portion whose diameter increases toward the distal end,
The flare part is a second flare part,
The stent delivery device according to claim 13, wherein the axial length of the second flared portion is greater than or equal to the axial length of the first flared portion. 15. The stent delivery device according to claim 14, wherein the second flared portion is provided at a distal end portion of the plurality of components. Consists of a first stent and a second stent,
The first stent has a sleeve made of a resin film,
A stent set, wherein a self-expanding force of an axially intermediate portion of the second stent is greater than a self-expanding force of the sleeve of the first stent.

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