JP7277988B2 - Stent graft with fenestration - Google Patents

Description

This invention relates to stent grafts with fenestration sections.

In order to treat aortic aneurysms containing branches, artificial blood vessel replacement and stent graft insertion are known. For example, fenestrated or branched stent grafts are used for stent graft insertion. However, since the position of the branches differs from patient to patient, many sizes and shapes are required, which poses problems in terms of manufacturing and popularization.

Patent No. 5788542

A stent-graft with a fenestration that allows the branch stent-graft to be inserted anywhere during surgery, for example, to preserve the branch vessels near the aortic aneurysm is desired. Conventional stent grafts have a problem of interference between stent rows and branch stent grafts.

One of the embodiments disclosed in this specification relates to stent grafts.
This stent graft 1 is
a stent 5 comprising a plurality of stent rows 3;
It includes a graft 7 in contact with the stent.
The stent graft 1 has a fenestration portion 9 in a portion of the graft 7 to facilitate insertion of another stent graft, a branch stent graft. The fenestration portion 9 is a portion for preventing the branch stent graft from interfering with the stent rows of the stent graft.

Since a portion of the graft 7 has a fenestration portion that facilitates insertion of the branch stent graft, the branch stent graft can be inserted using the fenestration portion without interference between the stent row of this stent graft and the branch stent graft.

In a preferred embodiment of this stent graft, among the plurality of stent rows 3, at least a portion of the fenestration surrounding stent row 11, which is a stent row positioned around the fenestration portion, is not fixed to the graft 7. . By doing so, it is possible to more effectively prevent interference between the stent row and the branch stent graft.

In a preferred embodiment of this stent graft, the fenestration partial peripheral stent row 11 is loop-shaped without a plurality of ridges and valleys. With such a structure, this stent graft can more effectively prevent interference between the loop-shaped stent row and the branch stent graft.

In a preferred embodiment of this stent graft, the fenestration partial perimeter stent rows 11 have wider spacing between the stent rows than the other stent rows. With such a structure, this stent graft can more effectively prevent interference between the stent row and the branch stent graft.

A preferred embodiment of this stent graft comprises:
The fenestration partial graft, which is a graft located in the fenestration portion, is easier to puncture than the graft site in the region other than the fenestration partial graft, and has excellent durability and elasticity. With such a structure, the stent graft is durable and can prevent leakage after insertion of the branch stent graft.

A preferred embodiment of this stent graft comprises:
The fenestration portion has an X-ray opaque marker fixing portion 19 . . With such a structure, the stent graft can identify the fenestration portion under fluoroscopy.

The present invention provides a stent graft with a fenestration into which a branch stent graft can be inserted.

FIG. 1 is a conceptual diagram of a stent graft, which is one of the embodiments disclosed in this specification. FIG. 2 is a conceptual diagram showing an example of a partially perimeter stent array for fenestration that differs in structure from existing stent arrays. FIG. 3 is a conceptual diagram showing an example in which the interval between fenestration partial peripheral stent rows is wider than the interval between other stent rows. FIG. 4 is a conceptual diagram showing an example in which at least a portion of the partial perimeter stent row for fenestration is not fixed to the graft. FIG. 5 is a conceptual diagram showing an example of thickening the graft at the portion corresponding to the fenestration. FIG. 6 is a conceptual diagram showing an example of thickening the graft at the portion corresponding to the fenestration. FIG. 7 is a conceptual diagram showing an example of a normal stent provided with a window portion for inserting a branch stent. FIG. 8 is a photograph in lieu of a drawing showing how holes are made in the stent graft. FIG. 9 is a photograph in lieu of a drawing showing how a stent graft is being perforated. FIG. 10 is a photograph in lieu of a drawing showing an example of a stent graft having a branch stent graft. FIG. 11 is a photograph in lieu of a drawing showing an example of a stent graft having a branch stent graft.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments for carrying out the present invention will be described below with reference to the drawings. The present invention is not limited to the embodiments described below, and includes appropriate modifications within the scope obvious to those skilled in the art from the following embodiments.

FIG. 1 is a conceptual diagram of a stent graft, which is one of the embodiments disclosed in this specification. As shown in FIG. 1, this stent graft 1 comprises a stent 5 comprising a plurality of stent rows 3 and a graft 7 in contact with the stent. Although the number of stent rows 3 varies depending on the stent graft, examples of the number of stent rows 3 are 2 or more and 50 or less, 4 or more and 20 or less, or 5 or more and 15 or less.

A stent graft 1, which is an example of this, has a tubular (cylindrical) structure extending along its axial direction (Z-axis direction). An example of the axial length of the stent graft 1 is 10 to 30 cm. This length varies depending on the application and target. An example of the expanded outer diameter of the stent graft 1 is 20-50 mm.

The stent 5 is configured using, for example, one or more wires (strands). A stent has, for example, a tubular (cylindrical) structure. The stent may have multiple stent rows 3 . Each stent row may have an undulation with peaks and valleys, and each stent row may be annular. The stent may have a tubular structure composed of a mesh structure, and such a tubular mesh structure may be formed by weaving wires in a predetermined pattern. A cylindrical network structure may be formed by arranging one or more pieces of wire that are bent in a zigzag shape and processed into a cylindrical shape.

A metal wire is preferable as a material for the wire rod constituting the stent 5, and a shape memory alloy to which a shape memory effect or superelasticity is imparted by heat treatment is particularly preferable. Examples of wire materials include stainless steel, tantalum (Ta), titanium (Ti), platinum (Pt), gold (Au), and tungsten (W). Examples of shape memory alloys include nickel (Ni)-Ti alloys, copper (Cu)-zinc (Zn)-X (X = aluminum (Al), iron (Fe), etc.) alloys, Ni-Ti-X (X = Fe, Cu, vanadium (V), cobalt (Co), etc.) alloy. Wire synthetic resin may be used. The wire may be a metal wire whose surface is coated with, for example, Au or Pt.

The graft 7 has, for example, a tubular (cylindrical) shape as shown in FIG. placed. For example, the graft 7 is preferably arranged so as to cover the outer peripheral side of the stent 5 (wire). Each stent row 3 may be fixed with a graft.

The graft 7 may be connected (fixed) to the stent 5 by, for example, sewing, gluing, or welding. In this case, the graft 7 preferably covers and connects the stent 5 so as not to affect the expansion and contraction of the stent 5 . It should be noted that such connecting portions between the graft 7 and the stent 5 may be appropriately provided, for example, at both end portions or an intermediate portion of the stent 5 .

Examples of such a graft 7 include a tubular thermoplastic resin formed by a molding method such as extrusion molding or blow molding, a tubular woven fabric made of thermoplastic resin fibers or ultrafine metal wires, Cylindrical nonwoven fabrics made of thermoplastic resin or ultra-fine metal, cylindrical flexible resin sheets or porous sheets, resin dissolved in a solvent are formed into thin cylinders by the electrospinning method. It is a struct.

Examples of knitted fabrics are known knitted fabrics and woven fabrics such as plain weaves and twill weaves. As a graft, a crimped graft or the like can be used. As the graft, a woven or woven fabric of thermoplastic resin fibers formed in a cylindrical shape, or a plain woven fabric of thermoplastic resin fibers formed in a cylindrical shape is preferable because of its excellent strength, porosity and productivity.

Examples of thermoplastic resins include polyolefins such as polyethylene, polypropylene, and ethylene-α-olefin copolymers; It is a resin such as fluororesin such as ethylene chloride and polypropylene fluoride, which has little durability and structural reaction. Of these, polyesters such as polyethylene terephthalate, and fluororesins such as polyethylene fluoride and polypropylene fluoride, which are chemically stable, highly durable, and less prone to tissue reaction, are preferably used as the material for the ingredients. be able to.

It is preferable to use a highly elastic material for the graft. If a highly elastic material is used, blood leakage can be prevented when the branch stent graft is inserted. However, it is preferable that the stent graft is made of a material that does not expand due to blood pressure. The stent graft expands when the puncture site is expanded to about 10 atmospheres with a balloon, but preferably does not expand under pressure. Such stent-grafts are known.

The stent graft 1 has a fenestration portion 9 in a portion of the graft 7 to facilitate insertion of another stent graft, a branch stent graft. The fenestration is the intended site for insertion of the branch stent graft. The stent graft 1 may be provided with the fenestration portion 9 at an appropriate location. The number of fenestration portions 9 may be appropriately adjusted according to the target site, and may be one, two, or three or more. The fenestration portion may also be designed for each patient. Since the stent graft 1 has a fenestration portion, the stent graft 1 is placed in a predetermined position such as the aorta. A window can be created for insertion of the stent graft. The shape of the fenestration portion 9 may be appropriately adjusted according to the target branch stent graft. Examples of shapes for the fenestration portion 9 are circular, oval, rectangular with rounded corners, and rugby ball. The size of the fenestration portion 9 may be designed in consideration of the shape of the target branch stent graft. Examples of the size of the fenestration portion 9 include a shape that fits within a region of 0.2 cm or more and 4 cm or less in width and 0.5 cm or more and 10 cm or less in length, and a shape that fits in a region of 0.5 cm or more and 2 cm or less in width and 1.5 cm or more and 6 cm or less in length. It is a shape that fits within a region, a shape that fits within a region of 0.8 cm or more and 1.2 cm or less in width and 2 cm or more and 4 cm or less in length.

Since a part of the graft 7 has a fenestration that facilitates the insertion of the branch stent graft, this stent graft can be inserted using a puncture/penetration instrument or a laser using the fenestration to match the position of the branched blood vessel. You can create a window for Using this window, the branch stent graft can be easily inserted without interfering with the stent row.

FIG. 2 is a conceptual diagram showing an example of a partially perimeter stent row for fenestration that differs in structure from other stent rows. As shown in FIG. 2, in a preferred embodiment of this stent graft, the fenestration partial perimeter stent row 11 is loop-shaped without a plurality of ridges and valleys. In this embodiment, the structure of the fenestration partial perimeter stent row 11 is preferably different from the structure of the other stent rows 3 . In other words, the stent row 11 around the fenestration portion of this embodiment is intended to make it easier to create the fenestration portion 9, and the other stent rows 3 maintain elasticity and strength in the same manner as ordinary stents. is intended. Examples of the shape of the partial perimeter stent array 11 for fenestration are a loop shape that takes the mathematical symbol infinity structure (8 horizontal structure), or a It is a ring-shaped one provided, or a ring-shaped one provided on a plane that obliquely crosses the axis of the stent.

FIG. 3 is a conceptual diagram showing an example in which the interval between fenestration partial peripheral stent rows is wider than the interval between other stent rows. As shown in FIG. 3, in a preferred embodiment of the stent graft, the partial perimeter fenestration stent rows 11 are more widely spaced than the other stent rows. By increasing the width of the stent row, a sufficient space for fabricating the window can be secured in advance. An example of the distance between two fenestration partial perimeter stent rows 11 is 0.5 cm or more and 4 cm or less, and may be 1 cm or more and 2 cm or less. The interval between the two fenestration partial peripheral stent rows 11 may be 1.1 times or more and 3 times or less, 1.2 times or more and 2.5 times or less, or 1.4 times the interval between the other stent rows. More than twice and less than 2.4 times may be sufficient. In this example, as in FIG. 4, there may be a portion 15 of this stent that is not fixed to the graft.

FIG. 4 is a conceptual diagram showing an example in which at least a portion of the partial perimeter stent row for fenestration is not fixed to the graft. As shown in FIG. 4, in a preferred embodiment of this stent graft, among the plurality of stent rows 3, a stent row around the fenestration portion 9, which is a stent row 11 located around the fenestration portion 9, is at least partially is not fixed to the graft 7. The portion 15 of the stent that is not anchored to the graft facilitates drilling for the branch stent graft and does not interfere with the stent array and branch stent graft. This portion 15 exists only on the side of the fenestration portion 9 of the fenestration portion surrounding stent row 11, and the portion of the fenestration portion surrounding stent row 11 on the back side of the fenestration portion 9 is the graft. and may be fixed. In addition, while the other stent rows are fixed to the graft, the entire fenestration partial peripheral stent row 11 may be in a state in which it is not fixed to the graft. Typically, the fenestration 9 lies between two fenestration peripheral stent rows 11 . The fenestration peripheral stent row 11 may be unfixed to the graft 7 in the region near the fenestration portion 9 and fixed to the graft 7 in the region away from the fenestration portion 9 . Of the total length of the fenestration partial circumference stent row 11 (the length of the stretched wire), the portion not fixed to the graft 7 may be 5% or more and 70% or less, 10% or more and 50% or less, or 10%. % or more and 40% or less, 10% or more and 30% or less, or 15% or more and 30% or less. The portion not fixed to the graft 7 is preferably continuous. The part that is not fixed to the graft 7 may be centered on the part where the fenestration part 9 exists, or it may be located at a position shifted from the part where the fenestration part 9 exists, considering the ease of opening the window. may exist centered on Since the area near the fenestration portion 9 is not fixed to the graft 7, it is easier to form the fenestration portion 9 in this portion.

FIG. 5 is a conceptual diagram showing an example of thickening the graft at the portion corresponding to the fenestration. FIG. 6 is a conceptual diagram showing an example of thickening the graft at the portion corresponding to the fenestration. A preferred embodiment of this stent graft is the graft 7 located in the fenestration portion 9. The fenestration partial graft is thicker or more elastic than the graft portion in the non-fenestration partial graft region of the graft. It is a thing. By increasing the thickness of the graft or making it elastic, creating a window reduces the strength of the graft and reduces the risk of rupture and blood leakage from the joint. As shown in FIGS. 5 and 6, another graft 17 may be superimposed and fixed on the graft corresponding to the fenestration. A fenestration partial graft should preferably be easier to puncture than other sites. For example, a thicker graft site than the non-fenestration partial graft area of the graft may reduce wobble of the graft section and facilitate puncture of the branch stent or instruments used to create holes for the branch stent.

In a preferred embodiment of this stent graft, the fenestration portion has an X-ray impermeable marker fixing portion 19 to which an X-ray impermeable marker is fixed. Since it has an X-ray impermeable marker fixing part, when inserting a branch stent graft, it is possible to confirm the position with X-rays. The X-ray impermeable marker is preferably one that does not affect the rigidity of the artificial blood vessel even after drying. Examples of X-ray opaque markers are iodinated poppy oil ethyl ester (Patent No. 5959118) and barium sulfate (Patent No. 4798662). A radio-opaque marker anchor may be formed by sewing a thread containing the radio-opaque marker to the graft.

This stent graft is implanted in the intended patient. Afterwards, a hole is made in the fenestration part. FIG. 7 is a conceptual diagram showing an example in which the stent rows have the same shape and the intervals between the stent rows are constant, as shown in FIG. 7 as a reference example. As shown in FIG. 7, if a conventional stent graft is used as it is, a sufficient space for providing a branch stent cannot be secured due to the presence of the metal stent in the stent graft depending on the position of the hole in the fenestration portion. FIGS. 8 and 9 are photographs in lieu of drawings showing how holes are made in a conventional stent graft. Then, the branch stent graft 21 is inserted into the hole. The branch stent graft is fixed to the stent graft by the expansion force of the branch stent graft. In this way, a stent-graft with branch stent-grafts can be placed in the patient's body. 10 and 11 are photographs instead of drawings showing examples of stent grafts having branch stent grafts. In the examples of FIGS. 10 and 11, the hole in the fenestration portion is made at an appropriate position by chance, and the space for installing the branch stent can be secured, but in actual clinical practice, such an indicated position cannot be selected. On the other hand, with the stent graft proposed in this application, if the fenestration portion is punctured, the branch stent graft can be inserted, expanded, and fixed without difficulty.

INDUSTRIAL APPLICABILITY This invention can be used in the field of medical equipment.

REFERENCE SIGNS LIST 1 stent graft 3 stent row 5 stent 7 graft 9 fenestration 11 stent row around fenestration 15 portion of stent not fixed to graft 17 graft 19 X-ray impermeable marker fixing portion 21 branch stent graft

Claims (7)

A stent graft comprising a stent comprising a plurality of stent rows and a graft in contact with the stent, the stent graft being used to treat an aortic aneurysm in an aorta having branch vessels,
The stent graft has a fenestration portion for inserting a branch stent graft for preserving the branch blood vessel in a portion of the graft that does not interfere with the plurality of stent rows,
The fenestration portion is a portion for creating a window for inserting the branch stent graft at a position corresponding to the branch blood vessel of the patient in which the stent graft is to be implanted, the stent graft comprising:
The fenestration partial peri-fenestration stent row, which is the stent row positioned around the fenestration partial graft, which is the graft positioned in the fenestration portion, is not fixed to the graft in the region near the fenestration portion, The fenestration partial graft is more elastic than the graft site in the graft other than the fenestration partial graft,
stent graft. A stent graft according to claim 1,
The portion of the stent that is not fixed to the graft exists only on the side of the stent row around the fenestration portion on which the fenestration portion exists, and the fenestration portion on the back side of the fenestration portion. A portion of the peripheral stent row is secured to the graft,
A stent graft bendable around the fenestration . A stent graft according to claim 2,
The stent graft, wherein the fenestration partial perimeter stent row has a loop shape that does not have a plurality of crest-and-valley structures. A stent graft according to claim 2,
The stent graft according to claim 1 , wherein the fenestration partial perimeter stent rows are spaced wider than the stent rows other than the fenestration partial perimeter stent rows among the plurality of stent rows . A stent graft according to claim 1,
A stent graft, wherein a fenestration partial graft, which is a graft located in the fenestration portion, is formed integrally with a graft portion of the graft other than the fenestration partial graft. A stent graft according to claim 1,
The stent graft, wherein the fenestration portion has an X-ray opaque marker fixing portion. A stent graft according to claim 1,
The fenestration portion is a portion to be fabricated by indwelling the stent graft at a predetermined position in the aorta and using a puncture/piercing instrument or irradiating a laser according to the position of the branch vessel . stent graft.

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