WO2021182206A1

WO2021182206A1 - Gastrointestinal stent

Info

Publication number: WO2021182206A1
Application number: PCT/JP2021/008061
Authority: WO
Inventors: 中谷　誠一
Original assignee: 川澄化学工業株式会社
Priority date: 2020-03-09
Filing date: 2021-03-03
Publication date: 2021-09-16
Also published as: JPWO2021182206A1

Abstract

Provided is a gastrointestinal stent that can be placed accurately at a placement target site of the gastrointestinal tract. The gastrointestinal stent (1) is equipped with: cylindrical skeleton (20) that is capable of expanding and contracting in the radial direction, which is substantially orthogonal to the axial direction; and conversion means (31, 32) capable of keeping axial-direction portions (21, 22) of the skeleton in a contracted state and converting portions from a contracted state to an expanded state with the skeleton released from a sheath (110). A plurality of portions are provided to allow axial-direction positions of the skeleton to be different from each other, and a plurality of conversion means are provided in a manner corresponding to the plurality of portions.

Description

Gastrointestinal stent

The present invention relates to a gastrointestinal stent.

Conventionally, it is placed in a stenosis or obstruction formed in a gastrointestinal lumen (hereinafter referred to as "gastrointestinal tract") such as the esophagus, stomach, small intestine, large intestine, and bile duct, and the lesion site is enlarged in diameter to expand the gastrointestinal tract. Gastrointestinal stents that maintain a patency state are known (see, for example, Patent Document 1).

Japanese Patent No. 4651943

By the way, the gastrointestinal stent is delivered to the indwelling target site by the stent indwelling system, but is housed in the sheath of the stent indwelling system in a state of contracting in the radial direction and extending in the axial direction. Therefore, it is difficult to release the stent from the sheath smoothly, and when the skeleton of the gastrointestinal stent is released from the sheath and expands, the gastrointestinal stent is shortened in the axial direction. Is difficult. In particular, a gastrointestinal stent having a skeleton in which a wire rod is spirally wound has a large shortening rate, and the above-mentioned problem is remarkable.

An object of the present invention is to provide a gastrointestinal stent that can be accurately placed at a target site for placement of the gastrointestinal tract.

The gastrointestinal stent according to the present invention
A gastrointestinal stent that is placed in the gastrointestinal tract
A tubular skeleton that can be expanded and contracted in the radial direction, which is approximately orthogonal to the axial direction,
A conversion means capable of maintaining an axial part of the skeleton in a contracted state and converting the part from a contracted state to an expanded state in a state where the skeleton is released from the sheath is provided.
A plurality of the portions are provided so that the axial positions of the skeletons are different from each other.
A plurality of the conversion means are provided corresponding to the plurality of said portions.

According to the present invention, the gastrointestinal stent can be accurately placed at the indwelling target site of the gastrointestinal tract.

FIG. 1 is a diagram schematically showing a large intestine stent according to an embodiment. FIG. 2 is a schematic diagram showing an example of the first conversion means and the second conversion means. 3A and 3B are diagrams showing the configuration of the stent placement system. 4A to 4D are diagrams showing an example of a state change during placement of a large intestine stent. 5A-5D are views showing another example of a state change during placement of a large intestine stent.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, as an example of the present invention, it is placed in the large intestine in order to treat the occlusion (stenosis) by expanding the lesion site of the large intestine (for example, the obstruction or stenosis of the large intestine) radially outward. The large intestine stent 1 will be described.

FIG. 1 is a diagram schematically showing a large intestine stent 1 according to an embodiment. As shown in FIG. 1, the large intestine stent 1 has a tubular shape that defines a tubular flow path through which digested material flows. The large intestine stent 1 is a unilateral flare type bare stent composed of only the skeleton 20.

The colorectal stent 1 has a restraining portion 11 that is maintained in a contracted state when released from the sheath 110 (see FIG. 3A) and a non-restraining portion 12 that expands as the sheath 110 is released. The large intestine stent 1 is placed at the lesion site in the large intestine so that the restraint portion 11 is on the upstream side (oral side) in the flow direction of the digested product and the non-restraint portion 12 is on the downstream side (anal side) in the flow direction of the digestive product. NS. In the following description, the left side (end side of the restraint portion 11) in FIG. 1 will be referred to as the distal side S1, and the right side (end side of the non-restraint portion 12) will be referred to as the proximal side S2.
The colonic stent 1 may have an extension restricting portion for suppressing expansion and contraction in the axial direction.

The skeleton 20 is a reinforcing member for maintaining the expanded state of the large intestine stent 1. The skeleton 20 is self-expandable from a contracted state contracted inward to an expanded state expanded outward in a radial direction substantially orthogonal to the axial direction.

The skeleton 20 is formed by, for example, weaving a wire rod into a tubular shape. In the skeleton 20, for example, two wire rods extending spirally while being folded back in a zigzag shape (Z shape) at a predetermined pitch are formed with a bent portion (one mountain portion (a portion convex on one end side in the axial direction)). The other valley portion (the portion convex toward the other end in the axial direction) is woven into a diamond-shaped wire mesh (fence-like) so as to mesh with each other. In this case, when tension is applied to the large intestine stent 1 in the axial direction, the bent portions of the wire rods forming the mesh intersect closely with each other, so that the extension in the axial direction is restricted. As a result, the axial length of the large intestine stent 1 does not fluctuate significantly during placement, so that the large intestine stent 1 can be properly placed at a desired placement site.

The skeleton 20 is not limited to the above-mentioned skeleton structure, and for example, one metal wire rod is alternately formed with mountain portions (bent portions on the tip side) and valley portions (bent portions on the rear end side). It may be composed of a spiral skeleton wound spirally while bending in a zigzag shape (Z shape) as described above. Further, the skeleton 20 may be formed by laser processing a metal cylindrical member. Furthermore, the number of wire rods forming the skeleton 20 may be plurality.

Examples of the material forming the skeleton 20 include known metals or metal alloys typified by stainless steel, nickel-titanium alloy (Nitinol), titanium alloy and the like. Further, an alloy material having X-ray contrast property may be used. In this case, the position of the large intestine stent 1 can be confirmed from outside the body.
The skeleton 20 may be formed of a material other than the metal material (for example, ceramic or resin).

Further, the skeleton 20 is configured to be deformable according to an external force applied from the outer surface side. As a result, even if an external force is applied to the large intestine stent 1 from the outer surface side, the skeleton 20 is deformed, so that the lesion site of the large intestine can be continuously expanded while staying at the indwelling site without causing kink.

The material of the wire forming the skeleton 20, the wire type (for example, a circular wire such as a wire or a square wire obtained by laser cutting), the cross-sectional area (corresponding to the wire diameter in the case of a round wire), the number of bends in the circumferential direction, and The bending shape (the number of peaks and the shape of the peaks), the wire spacing in the axial direction (the amount of skeleton per unit length), and the like can be determined, for example, on the sheath required for the colonic stent 1 depending on the placement site. It is appropriately selected based on storability, release from the sheath, indwellability (corresponding to expanding force), flexibility (flexibility), and the like.

The skeleton 20 has a first skeleton portion 21 and a second skeleton portion 22 arranged in the restraint portion 11, and a third skeleton portion 23 arranged in the non-restraint portion 12. The first skeleton portion 21 and the second skeleton portion 22 are formed so as to exhibit a straight shape, and the third skeleton portion 23 is formed so as to exhibit a flare shape.
In FIG. 1, the boundary between the first skeleton portion 21 and the second skeleton portion 22 is shown by a broken line.

The first skeleton portion 21 is restrained so that the contracted state is maintained by the first conversion means 31 (see FIG. 2), and the second skeleton portion 22 is contracted by the second conversion means 32 (see FIG. 2). Restrained to be maintained.
On the other hand, the third skeleton portion 23 is not restrained and expands as it is released from the sheath 110.

The first conversion means 31 can maintain the first skeleton portion 21 in the contracted state while the skeleton 20 is released from the sheath, and can convert the first skeleton portion 21 from the contracted state to the expanded state according to a predetermined operation. It has a various configurations.
The second conversion means 32 can maintain the second skeleton portion 22 in the contracted state while the skeleton 20 is released from the sheath, and can convert the second skeleton portion 22 from the contracted state to the expanded state according to a predetermined operation. It has a various configurations.
The first conversion means 31 and the second conversion means 32 can be independently operated so that the timing of expanding the first skeleton portion 21 and the second skeleton portion 22 can be flexibly controlled while checking the indwelling state and the like. It is configured in.

Next, the first conversion means 31 and the second conversion means 32 will be described in detail with reference to FIG.
FIG. 2 is a schematic diagram showing specific examples of the first conversion means 31 and the second conversion means 32. The configuration shown in FIG. 2 is an example of the first conversion means 31 and the second conversion means 32, and other configurations may be applied.

As shown in FIG. 2, the first conversion means 31 and the second conversion means 32 are restrained by, for example, the

restraint members

31A and 32A wound around the outer peripheral surfaces of the first skeleton portion 21 and the second skeleton portion 22. It is composed of holding

members

31B and 32B that engage with the

members

31A and 32A, respectively. The first conversion means 31 and the second conversion means 32 are attached, for example, by attaching the large intestine stent 1 to the inner rod 120 and contracting it in the radial direction.

In the example shown in FIG. 2, the

restraint members

31A and 32A are wound around the outer peripheral surfaces of the first skeleton portion 21 and the second skeleton portion 22 in the circumferential direction, bent every rotation, and wound in the opposite direction. There is. On the other hand, the holding

members

31B and 32B are arranged along the axial direction of the first skeleton portion 21 and the second skeleton portion 22, and are engaged with the bent portions B formed on the restraining

members

31A and 32A. That is, the

restraint members

31A and 32A are wound in such a manner that they cannot hold the wound state by themselves, and are held so as not to fall off by engaging with the holding

members

31B and 32B. Therefore, when the engagement between the

restraint members

31A and 32A and the holding

members

31B and 32B is released, the

restraint members

31A and 32A naturally fall off from the first skeleton portion 21 and the second skeleton portion 22. As a result, the first skeleton portion 21 and the second skeleton portion 22 are released from the contracted state and shift to the expanded state.

One end of the

restraint members

31A and 32A is drawn out from, for example, a branch port 112a provided in the hub 112 (see FIG. 3B and the like). One end of the holding

members

31B and 32B is, for example, although not shown, pulled out from an opening provided separately from the branch opening 112a so that the holding

members

31B and 32B can be pulled out while making fine adjustments by rotating the dial or the like. It has become.

The restraining

members

31A and 32A and the holding

members

31B and 32B are formed of, for example, a material having a predetermined strength and rigidity, for example, sutures such as nylon fibers and fluorine fibers, and metal thin wires made of nickel-titanium alloy or stainless steel. A resin string-like member can be applied.
The restraining

members

31A and 32A and the holding

members

31B and 32B are preferably made of different materials in order to improve the slipperiness when pulled out.

3A and 3B are diagrams showing the configuration of the stent placement system 100. FIG. 3A shows a disassembled state of the stent placement system 100, and FIG. 3B shows a state in which the stent placement system 100 is assembled. In addition, in FIG. 3A and FIG. 3B, in order to facilitate understanding of the invention, the size (length, diameter, etc.) and shape of each member constituting the stent placement system 100 are schematically shown. Further, FIGS. 3A and 3B show a case where the configuration shown in FIG. 2 is applied to the first conversion means 31 and the second conversion means 32.

The stent placement system 100 is used, for example, by inserting it into the forceps hole of an endoscope when the large intestine stent 1 is placed in the large intestine. As shown in FIGS. 3A and 3B, the stent placement system 100 is arranged inside the tubular sheath 110 and the sheath 110, and is configured to be able to move forward and backward in the sheath 110 along the axial direction (longitudinal direction) of the sheath 110. The inner rod 120 is provided.

The sheath 110 is provided, for example, on a tubular sheath body 111 made of a flexible material and on the proximal side (right side in FIGS. 3A and 3B) of the sheath body 111, and the inner rod 120 is sheathed. It has a hub 112 (practitioner operation unit) for fixing and releasing the main body portion 111.

The inner rod 120 is located on, for example, a rod-shaped rod main body 121, a holding portion 122 formed with a diameter smaller than that of the rod main body 121 and holding the large intestine stent 1 in a contracted state, and a distal side of the inner rod 120. It has a tip 123 provided with the tip.

Although not shown, the rod body 121, the holding portion 122, and the tip tip 123 have, for example, a lumen for a guide wire for passing a guide wire and a large intestine stent 1 in a contracted state for expanding in the affected portion. A lumen for the trigger wire for passing the trigger wire of the above is formed along the axial direction of the inner rod 120.
Further, the rod body portion 121, the holding portion 122, and the tip tip 123 are formed of various materials having appropriate hardness and flexibility, such as resin and metal, but detailed description thereof will be omitted here.

The large intestine stent 1 is attached to the holding portion 122 of the inner rod 120 and is housed in the sheath 110 in a contracted state that can be expanded in the radial direction. The large intestine stent 1 is attached, for example, so that the unrestrained portion 12 is on the proximal side S2 (hub 112 side). Specifically, when the large intestine stent 1 is attached to the inner rod 120, it is brought into a contracted state by being folded in the radial direction while extending in the axial direction, and is housed in the sheath 110. At this time, the first skeleton portion 21 and the second skeleton portion 22 are held in the contracted state by the first conversion means 31 and the second conversion means 32. One ends of the restraining

members

31A and 32A and the holding

members

31B and 32B are pulled out from the opening provided in the sheath 110 (for example, the branch opening 112a in FIG. 3A).

FIGS. 4A to 4D are diagrams showing changes in the state of the large intestine stent 1 during placement. In addition, in FIGS. 4A to 4D, the large intestine stent 1 is schematically shown, and the detailed configuration of the first conversion means 31 and the second conversion means 32 is not shown.

When the large intestine stent 1 is placed at the lesion site L (placement target site) of the large intestine C, the sheath 110 and the inner rod 120 are inserted from the anal side along a guide wire (not shown) previously introduced into the large intestine C. , The large intestine stent 1 is positioned so as to be located at the lesion site L (see FIG. 4A).

Next, in the positioned state, the sheath 110 is moved to the proximal side S2 (anal side), and the large intestine stent 1 is released from the sheath 110 (see FIG. 4B). At this time, the first skeleton portion 21 and the second skeleton portion 22 of the large intestine stent 1 are restrained by the first conversion means 31 and the second conversion means 32 and are maintained in a contracted state, while only the third skeleton portion 23. Extends. The colonic stent 1 may be released from the sheath 110 by moving the inner rod 120 so as to push it toward the mouth while the position of the sheath 110 is fixed.

As in the past, when the entire large intestine stent is expanded due to release from the sheath, it is positioned by the expanding force of the large intestine stent, and it is difficult to adjust the indwelling position. In addition, when the colonic stent expands from the distal side S1 to the proximal side S2 in order, the indwelling state can be confirmed endoscopically, so it is difficult to adjust the indwelling position during the indwelling. be. On the other hand, in the present embodiment, when the sheath 110 is released, only the third skeletal portion 23 of the large intestine stent 1 expands, so that the state shown in FIG. 4B passes through the position of the proximal side S2. The placement position of the large intestine stent 1 can be adjusted while checking endoscopically, and the large intestine stent 1 can be easily placed in an appropriate position.

Next, the restraint by the first conversion means 31 is released, and the first skeleton portion 21 is released. For example, by pulling out the restraint member 31A or the holding member 31B, the restraint by the first conversion means 31 is released. As a result, only the first skeleton portion 21 shifts to the expanded state (see FIG. 4C). At this time, the second skeleton portion 22 is maintained in a contracted state by the second conversion means 32.

Next, the restraint by the second conversion means 32 is released, and the second skeleton portion 22 is released. For example, by pulling out the restraint member 32A and the holding member 32B, the restraint by the second conversion means 32 is released. As a result, the second skeletal portion 22 also shifts to the expanded state, the large intestine stent 1 is completely expanded, and the patency state of the large intestine C is secured (see FIG. 4D). After that, although not shown, the colonic stent 1 is placed at the lesion site L by releasing the engagement state between the colonic stent 1 and the inner rod 120 and pulling out the inner rod 120.

When the large intestine stent 1 is expanded in the order shown in FIGS. 4A to 4D, the proximal side S2 (third skeletal part 23) and the distal side S1 (first skeletal part 21) of the large intestine stent 1 are fixed to the large intestine C. In this state, the central portion (second skeletal portion 22) of the large intestine stent 1 is expanded, so that the displacement due to shortening or jumping of the large intestine stent 1 can be suppressed. As a result, the large intestine stent 1 can be appropriately placed even in a diseased part (particularly near the rectum) where strict position adjustment of the stent end is required.

As described above, the large intestine stent 1 according to the present embodiment is a large intestine stent placed in the large intestine C (gastrointestinal tract), and has a tubular skeleton 20 that can be expanded and contracted in the radial direction substantially orthogonal to the axial direction. With the skeleton 20 released from the sheath 120, the first skeleton portion 21 and the second skeleton portion 22 (a part of the skeleton in the axial direction) are maintained in a contracted state, and the first skeleton portion 21 and the second skeleton portion are maintained. A first conversion means 31 and a second conversion means 32 (conversion means) capable of converting 22 from a contracted state to an expanded state are provided. The first skeleton portion 21 and the second skeleton portion 22 are provided so that the positions of the skeleton 20 in the axial direction are different from each other. It is provided so as to correspond to the two skeleton portions 22.

As a result, the large intestine stent 1 can be partially expanded in the axial direction in various modes depending on the introduction direction, the placement site, and the like of the stent placement system 100, and the large intestine stent can be accurately located at the placement target site of the large intestine C. 1 can be detained.

Further, in the large intestine stent 1, the skeleton 20 further has a third skeleton portion 23 (other portion) whose axial position is different from that of the first skeleton portion 21 and the second skeleton portion 22 (part), and is from the sheath 110. After the release, the third skeleton portion 23 expands while the first skeleton portion 21 and the second skeleton portion 22 are contracted. As a result, the placement position can be adjusted in a state where the large intestine stent 1 is temporarily placed by expanding the third skeleton part 23, and then the first skeleton part 21 and the second skeleton part 22 can be expanded and the main placement can be performed. , The large intestine stent 1 can be accurately placed at the placement target site of the large intestine C.

Further, in the large intestine stent 1, the first conversion means 31 and the second conversion means 32 (plurality of conversion means) are configured to be independently operable. As a result, the timing of expanding the first skeleton portion 21 and the second skeleton portion 22 can be flexibly controlled while checking the indwelling state and the like, and the large intestine stent 1 can be indwelled at an appropriate position. In addition, a stable procedure is realized regardless of the experience and skill of the practitioner.

Further, in the large intestine stent 1, the skeleton 20 is formed by weaving a wire rod into a fence shape. As a result, the axial length of the large intestine stent 1 does not fluctuate significantly during placement, so that the large intestine stent 1 can be properly placed at a desired placement site.

Although the invention made by the present inventor has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment and can be changed without departing from the gist thereof.

For example, in the embodiment, a case will be described in which the restraint portion 11 is expanded in the order of the first skeleton portion 21 and the second skeleton portion 22 from the distal side S1 after the third skeleton portion 23 which is the non-restraint portion 12 is expanded. However, this is just an example and is not limited to this. For example, depending on the condition of the lesion site, the placement position in the large intestine C, and the like, as shown in FIGS. 5A to 5D, the restraint portion 11 is expanded in the order of the proximal side S2, the second skeleton portion 22, and the first skeleton portion 21. You may.

Further, in the above embodiment, the first conversion means 31 and the second conversion means 32 having independent configurations are provided, but the present invention is not limited to this, and the restraint member and the holding member are commonly used. You may use it. For example, the shapes and lengths of the restraint member and the holding member may be adjusted so that the first skeleton portion 21 and the second skeleton portion 22 are released in a predetermined order according to the amount of movement and the operation mode.
Further, the number of conversion means is an example and is not limited to this, and for example, three or more may be provided.

Further, in the embodiment, the unilateral flare type bare stent has been described as an example as the large intestine stent 1, but the present invention is not limited to this and can be arbitrarily changed as appropriate. The present invention can also be applied to, for example, bilateral flare type and straight type gastrointestinal stents. The present invention can also be applied to a covered stent in which a coating is entirely or partially placed on the peripheral surface of the skeleton.

Furthermore, the present invention is not limited to the large intestine stent 1 described in the embodiment, and can be applied to a gastrointestinal stent placed in the gastrointestinal tract such as the esophagus and the large intestine, and further to a stent graft placed in a blood vessel. In this case, the fluid flowing through the digestive tract is, for example, food that has not been digested at all, food that has just been ingested, food that has been decomposed by passing through the digestive tract, and that is not digested even if it passes through the digestive tract. The state of the substance does not matter, including things (for example, stool, etc.).

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The disclosures of the specifications, drawings and abstracts contained in the Japanese application of Japanese Patent Application No. 2020-040277 filed on March 9, 2020 are all incorporated herein by reference.

1 Large intestine stent (gastrointestinal stent)
20 Skeleton 21 First skeleton (part)
22 Second skeleton (part)
23 Third skeleton (other parts)
31 First conversion means (conversion means)
32 Second conversion means (conversion means)
C large intestine (gastrointestinal tract)

Claims

A gastrointestinal stent that is placed in the gastrointestinal tract
A tubular skeleton that can be expanded and contracted in the radial direction, which is approximately orthogonal to the axial direction,
A conversion means capable of maintaining an axial part of the skeleton in a contracted state and converting the part from a contracted state to an expanded state in a state where the skeleton is released from the sheath is provided.
A plurality of the portions are provided so that the axial positions of the skeletons are different from each other.
A plurality of the conversion means are provided corresponding to the plurality of said portions, and the gastrointestinal stent.
The skeleton further has another portion whose axial position is different from that of the portion.
The gastrointestinal stent according to claim 1, wherein the other portion expands in a state in which the plurality of said portions are contracted after being released from the sheath.
The gastrointestinal stent according to claim 1 or 2, wherein the plurality of conversion means are configured to be independently operable.
The gastrointestinal stent according to any one of claims 1 to 3, wherein the skeleton is a wire rod woven into a fence shape.