WO2021044856A1

WO2021044856A1 - Film for tubular therapeutic tool and tubular therapeutic tool

Info

Publication number: WO2021044856A1
Application number: PCT/JP2020/031413
Authority: WO
Inventors: ▲晄▼中陳
Original assignee: 川澄化学工業株式会社
Priority date: 2019-09-04
Filing date: 2020-08-20
Publication date: 2021-03-11
Also published as: JPWO2021044856A1

Abstract

Provided is a film for a tubular therapeutic tool which comprises a tubular film portion (12), wherein the film portion has a body layer (21) comprising fibers (21a), and the gaps between the fibers in the body layer are filled with a biocompatible sealing material (22) so that liquid permeability as a whole is relatively low.

Description

Membrane body for tubular treatment tool and tubular treatment tool

The present invention relates to a membrane body for a tubular treatment tool and a tubular treatment tool.

For example, a stent graft has been conventionally known as a tubular therapeutic tool used for treating an aortic aneurysm or aortic dissection occurring in the aorta (see, for example, Patent Documents 1 and 2).
The stent graft includes, for example, a skeleton portion using a metal wire and a coating portion that covers the skeleton portion, and has a tubular outer shape as a whole. The stent graft expands by applying an external force from the inside to the outside in the radial direction at a predetermined position in the blood vessel, and is placed in the blood vessel in close contact with the blood vessel.

Japanese Patent No. 6131441 Japanese Patent No. 5824759

It is preferable to use a fibrous material for the coating portion of the stent graft, for example, from the viewpoint of suppressing tearing or tearing due to suturing with the skeleton portion. Further, in order to suppress the inflow of blood to the lesion site when the stent graft is used, it is preferable that the liquid permeability of the film portion is low.
However, when a fiber material is used for the film portion, body fluid easily leaks from the gaps between the fibers, so there is room for improvement in achieving low liquid permeability.

An object of the present invention is to provide a membrane body for a tubular treatment tool and a tubular treatment tool that are less likely to tear or tear at suture while ensuring low liquid permeability.

One aspect of the present invention is a membrane body for a tubular therapeutic tool including a tubular coating portion, in which the coating portion has a main body layer made of fibers, and the main body layer has biocompatibility in the gaps between the fibers. The sealant is filled and the liquid permeability is relatively reduced as a whole.

Further, one aspect of the present invention is a tubular treatment tool, which includes a tubular film portion and a skeleton portion sutured on one surface of the film portion, and the film portion has a main body layer made of fibers. The main body layer is filled with a biocompatible sealing material in the gaps between the fibers, and the liquid permeability is relatively lowered as a whole.

According to the present invention, it is possible to prevent tearing or tearing in suturing while ensuring low liquid permeability.

It is a perspective view of the stent graft of one Embodiment to which this invention was applied. It is a figure which shows typically the structure of the film part. FIG. 2 is an enlarged view of a cross section of a portion surrounded by a broken line in FIG. It is a figure which shows typically the cross-sectional structure of the part surrounded by the broken line in FIG. FIG. 4 is a sectional view taken along line IIIb-IIIb of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In each figure described later, a configuration example of the stent graft 10 as an embodiment of the tubular treatment tool is schematically shown. The shapes, dimensions, etc. of the stent graft 10 in the drawings are schematically shown, and do not show the actual shapes, dimensions, etc.

FIG. 1 is a perspective view showing a schematic configuration of the stent graft 10 of one embodiment. FIG. 1 shows a state (use state) in which the stent graft 10 is placed in a blood vessel.

The stent graft 10 shown in FIG. 1 is a stent graft for blood vessels, and has a tubular shape as a whole. The stent graft 10 has openings provided at both ends in the axial direction Ax communicating with each other, and has a tubular flow path inside through which the patient's blood passes in the used state.
In the example of FIG. 1, a straight tube-shaped stent graft 10 is shown. However, the stent graft 10 of the present embodiment may have, for example, a shape curved in an arch shape (for example, a shape corresponding to the aortic arch of a patient) or a shape having a twist.

The stent graft 10 has a so-called self-expanding structure in which the shape of the expanded state is stored. The stent graft 10 is introduced into the blood vessel 30 in a state of being housed in a tubular sheath (not shown) and contracted inward in the radial direction (not shown). The stent graft 10 is carried to a predetermined position in the blood vessel 30 (for example, a lesion site 31 where an aortic aneurysm or the like is occurring), then released from the sheath, and expands radially outward. As shown in FIG. 1, the expanded stent graft 10 is placed in the blood vessel 30 in close contact with the inner wall of the blood vessel 30.

As shown in FIG. 1, the stent graft 10 includes a skeleton portion 11 and a coating portion 12 fixed to the skeleton portion 11. The film portion 12 is an example of a membrane body for a tubular therapeutic tool. Further, a bare portion 14 made of, for example, a metal skeleton is formed at one end of the axial direction Ax of the stent graft 10.
The bare portion 14 has a function of causing friction with the inner wall of the blood vessel 30 when the stent graft 10 is placed and suppressing a displacement (migration) of the stent graft 10.

The skeleton portion 11 is formed by, for example, spirally winding a thin metal wire (wire rod). For example, the skeleton portion 11 is formed by winding the thin metal wire spirally while bending so that peaks and valleys are alternately formed. The cross-sectional shape of the thin metal wire of the skeleton portion 11 is, for example, a circular shape or an elliptical shape.

The skeleton portion 11 is configured to be deformable so as to self-expand from a contracted state contracted inward in the radial direction to an expanded state expanded outward in the radial direction.

Examples of the material constituting the fine metal wire of the skeleton portion 11 include known metals or metal alloys typified by Ni—Ti alloy (Nitinol), cobalt-chromium alloy, titanium alloy, stainless steel and the like. The skeleton portion 11 may be made of a material other than metal (for example, ceramic or resin).

Further, for example, the material of the skeleton portion 11 (nitinol or the like), the cross-sectional area and cross-sectional shape of the thin metal wire of the skeleton portion 11 (circular wire rod such as a wire, or square wire rod by laser cutting), and the folding back of the skeleton portion 11 in the circumferential direction. The number of times, the folded shape (the number of peaks and the shape of the peaks), the spiral pitch of the skeleton portion 11 in the axial direction (the amount of skeleton per unit length of the stent graft 10), etc. It can be set to an appropriate value accordingly. Detailed description of these parameters will be omitted.

The film portion 12 is a tubular flexible film body that forms the above-mentioned tubular flow path, and is attached to the skeleton portion 11 so as to close the gap portion of the skeleton portion 11. In the present embodiment, as shown in FIG. 1, the film portion 12 is attached to the inside of the skeleton portion 11. Further, outer coating portions 12a that partially cover the skeleton portion 11 from the outside are attached to both ends of the stent graft 10 in the axial direction Ax.
The outer coating portion 12a may be formed by folding back the coating portion 12 from the inside to the outside of the skeleton portion 11, for example. Alternatively, the outer coating portion 12a may be formed by overlapping the outer coating portion 12 formed in a band shape from the outside of the skeleton portion 11.

The outer coating portion 12a may be attached so as to cover the skeleton portion 11 as a whole from the outside, that is, to sandwich and cover the skeleton portion 11 from the inside and the outside by using the two coating portions 12. ..
Further, the film portion 12 may be attached only to the outside of the skeleton portion 11.

The skeleton portion 11 of the present embodiment is sewn with the coating portion 12 and the thread 13 as shown in FIGS. 4 and 5 described later. The method of fixing the skeleton portion 11 and the coating portion 12 may be, for example, adhesion, welding, or sticking with a tape.

2 and 3 are diagrams schematically showing the configuration of the film portion 12. Further, FIG. 4 is a diagram schematically showing a cross-sectional structure of a portion surrounded by a broken line in FIG. 1, and FIG. 5 is a sectional view taken along line IIIb-IIIb of FIG.

The film portion 12 has a main body layer 21 made of a fabric of fibers 21a. The body layer 21 is composed of a woven fabric, knitted fabric or non-woven fabric made of a biocompatible fibrous material. FIG. 2-5 schematically shows an example in which the main body layer 21 of the film portion 12 is formed of a woven fabric, but the film portion 12 may be a knitted fabric or a non-woven fabric as described above. The woven fabric of the main body layer 21 may be woven in any of plain weave, twill weave, and satin weave.

Examples of the fiber material of the main body layer 21 include a polyester resin such as polyethylene terephthalate and a fluororesin such as PTFE (polytetrafluoroethylene).
The main body layer 21 can pass the thread 13 through the gap between the fibers 21a. Therefore, the main body layer 21 and the skeleton portion 11 can be sutured without reducing the strength against tearing or tearing of the main body layer 21.

Fine holes are formed in the gaps between the fibers 21a in the fabric of the main body layer 21, and as shown in FIG. 3, the gaps between the fibers 21a in the main body layer 21 are filled with the sealing material 22. FIG. 3 shows a state in which the sealing material 22 has entered the gap between the fibers 21a of the main body layer 21 and the surface of the main body layer 21 is covered with the sealing material 22. The sealing material 22 has a function of reducing the liquid permeability of the main body layer 21 by closing the gaps between the fibers 21a. That is, the main body layer 21 has a relatively low liquid permeability as a whole as compared with the one formed of the fiber alone.

The sealing material 22 is made of a resin material having lower liquid permeability than the fiber 21a of the main body layer 21 and having biocompatibility. Examples of the material of the sealing material 22 include polyethylene, silicone, urethane and the like.

The main body layer 21 may be filled with the sealing material 22 by, for example, sprinkling granular sealing material 22 on at least one surface of the main body layer 21 and then heating to melt the sealing material 22. Further, the solution of the sealing material 22 may be adhered to at least one surface of the main body layer 21 by dipping or the like, or the sheet of the sealing material 22 may be heat-pressed.
When heating is performed when the main body layer 21 is filled with the sealing material 22, a material having a melting point lower than that of the main body layer 21 is used for the sealing material 22.

By coating the surface of the main body layer 21 with the sealing material 22, it is possible to impart slipperiness to the main body layer 21 as compared with the case where there is no coating. As a result, the resistance when the stent graft 10 is loaded into the sheath and when the stent graft 10 is released from the sheath can be reduced, and the wear resistance can be improved. For example, when a material containing a polymer compound such as polyethylene (particularly, ultra-high molecular weight polyethylene having a molecular weight of about 1 million to 6 million) is used as the sealing material 22, the slipperiness of the main body layer 21 can be further improved. It can be done and is preferable.

Further, as the sealing material 22, for example, a biodegradable polymer such as polylactic acid may be applied. That is, polylactic acid is hydrolyzed in the living body and finally dissolved. However, at least for a predetermined period after the placement of the stent graft 10, the lesion site 31 (aortic aneurysm, etc.) is controlled by controlling the period until the gap between the fibers 21a of the main body layer 21 is closed by the thrombus. ), It is considered that the inflow of blood to) can be suppressed.

As described above, the stent graft 10 of the present embodiment includes a tubular film portion 12 and a skeleton portion 11 sutured on one surface of the film portion 12. The film portion 12 has a main body layer 21 made of fibers 21a, and the main body layer 21 is filled with a biocompatible sealing material 22 in the gaps between the fibers 21a, so that the liquid permeability is relatively lowered as a whole. ing.
According to the present embodiment, since the gaps between the fibers 21a of the main body layer 21 are closed by filling the sealing material 22, leakage of body fluid from the gaps between the fibers 21a of the main body layer 21 in the film portion 12 is suppressed. .. Therefore, according to the stent graft 10 of the present embodiment, it is possible to suppress the inflow of blood inside the stent graft 10 to the lesion site 31 on the outside.
Further, since the main body layer 21 of the film portion 12 can pass the thread 13 through the gap between the fibers 21a, the skeleton portion 11 is sewn to the main body layer 21 without reducing the strength against tearing or tearing of the main body layer 21. be able to. Therefore, according to the stent graft 10 of the present embodiment, tearing or tearing of the coating portion 12 due to suturing is less likely to occur.

Further, in the stent graft 10 of the present embodiment, the film portion 12 having reduced liquid permeability as a whole is used by filling the gaps between the fibers 21a of the main body layer 21 with a sealing material, so that the film portion can be formed only with the fabric. The thickness of the entire film portion can be reduced as compared with the case of configuration.
For example, when the film portion is composed of only the cloth, it is necessary to thicken the film portion in order to reduce the liquid permeability. If the film portion is thickened, there is a concern that the storability when the tubular treatment tool is stored in the sheath is deteriorated and the release property from the sheath is lowered.
On the other hand, in the present embodiment, since the gap between the fibers 21a of the film portion 12 is closed by the sealing material 22, the liquid permeability can be lowered even if the thickness of the main body layer 21 is small. As a result, according to the present embodiment, stent graft placement using a sheath having a smaller diameter than before becomes possible, and the burden (invasiveness) on the patient during the surgery can be further reduced.

Further, in the present embodiment, by coating the surface of the main body layer 21 with the sealing material 22 to impart slipperiness, it is possible to reduce the resistance when the stent graft 10 is released from the sheath. With such a configuration, it becomes easier to use a sheath having a smaller diameter than before in the stent graft placement operation, and the work of loading the stent graft 10 into the sheath becomes easy.

As described above, the present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
In addition, the embodiments disclosed this time should be considered to be exemplary and not restrictive in all respects. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

10 Stent graft (tubular treatment tool)
11 Skeleton part 12 Film part 13 Thread 21 Body layer 21a Fiber 22 Sealing material

Claims

A membrane body for a tubular treatment tool having a tubular coating portion,
The film portion has a main body layer made of fibers and has a main body layer.
The main body layer is a membrane body for a tubular therapeutic tool in which the gaps between the fibers are filled with a biocompatible sealing material, and the liquid permeability is relatively reduced as a whole.
The membrane body for a tubular therapeutic tool according to claim 1, wherein the sealing material is made of a material having a lower liquid permeability than the main body layer.
The membrane body for a tubular therapeutic tool according to claim 1 or 2, wherein the sealing material is made of a material having a melting point lower than that of the main body layer.
The membrane body for a tubular therapeutic tool according to any one of claims 1 to 3, wherein the surface of the main body layer is covered with the sealing material.
The membrane body for a tubular therapeutic tool according to any one of claims 1 to 4, wherein the skeleton portion of the tubular therapeutic tool is sutured on one surface of the film portion.
Tubular treatment tool
A tubular film portion and a skeleton portion sewn on one surface of the film portion are provided.
The film portion has a main body layer made of fibers and has a main body layer.
The main body layer is a tubular therapeutic tool in which the gaps between the fibers are filled with a biocompatible sealing material, and the liquid permeability is relatively reduced as a whole.