JP2013158352A - Stent graft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a stent graft therapy to be carried out efficiently and significantly reduce a burden to a patient which is involved with the therapy.SOLUTION: A stent graft 10 includes a cylindrical graft 12 having an axially-extended lumen 16, and a stent 14 supporting the cylindrical graft 12 and expandable in the radial direction of the cylindrical graft 12. The stent graft 10 brings the cylindrical graft 12 into close contact with the vascular wall 100a of the abdominal aorta 100 to which the renal artery 104 is connected by expansion of the stent 14. A plurality of opening and closing portions 18 connected to the lumen 16 are provided on the side of the cylindrical graft 12. The opening and closing portions 18 close when facing the inside of the abdominal aorta 100 and automatically open when facing the renal artery 104.

Description

  The present invention relates to a stent graft used for treatment of a biological lumen.

  Of the aorta (biological lumen) connected to the heart, the abdominal aorta descending below the diaphragm tends to cause an aortic aneurysm due to weakening of the arterial wall. The aortic aneurysm that occurs at this site is called an abdominal aortic aneurysm (AAA), and is particularly formed below the connection point of the renal artery (branch lumen). If the abdominal aortic aneurysm ruptures, the survival probability becomes very low, so early treatment is desired. There are mainly two methods for treating an abdominal aortic aneurysm. A surgical treatment in which a treatment site (abdominal aorta) is excised and replaced with an artificial blood vessel, and a stent graft treatment in which a stent graft is delivered through the blood vessel and a new blood flow path is formed in the abdominal aorta by the stent graft. Stent graft treatment is less burdensome on the patient than surgical treatment. For this reason, in recent years, the opportunity to perform stent graft treatment has increased.

  As shown in Patent Document 1, a stent graft used for stent graft treatment is constituted by a main graft (cylinder) that is in close contact with a blood vessel wall and a stent (structure) that supports the cylinder so as to be expandable and contractible. When performing a stent graft treatment, an operator incises the patient's buttocks, inserts a catheter containing the stent graft in a reduced diameter state into the blood vessel, and delivers it to the abdominal aorta. Then, one end of the stent graft is expanded (expanded in diameter) and locked to the upper healthy site (landing zone) interposed below the connecting site of the renal arteries and above the site of occurrence of the abdominal aortic aneurysm. In addition, the stent graft is deployed so that the torso passes through the abdominal aortic aneurysm, and the other end of the stent graft is locked to the lower healthy part of the common iliac artery (or abdominal aorta) downstream of the abdominal aorta. By doing so, the stent graft is placed in the aorta.

Japanese Patent No. 4052397

  By the way, in stent graft treatment, it is important to accurately position one end of the stent graft in the landing zone of the abdominal aorta so as not to block an artery (such as a renal artery or a superior mesenteric artery) that branches from the aorta. The length of this landing zone is usually short, although it depends on the symptoms of the abdominal aortic aneurysm. Therefore, in the stent graft treatment, there is a disadvantage that the stent graft cannot be easily locked in the landing zone, or that the stent graft is placed in a state shifted from a desired locking position.

  Furthermore, depending on the symptoms of the abdominal aortic aneurysm, the landing zone of the abdominal aortic aneurysm may be very short (or absent). In this case, there is also a problem that the stent graft treatment cannot be performed.

  The present invention has been made in view of the above circumstances, and ensures the communication between the living lumen and the branch lumen when the stent graft is placed in the vicinity of the living lumen to which the branch lumen is connected. However, it is possible to provide a stent graft that can be placed without depending on the position of a healthy part of a living body lumen, thereby enabling a procedure to be efficiently performed and significantly reducing the burden on a patient associated with treatment. With the goal.

  In order to achieve the above object, the present invention comprises a cylindrical body having a lumen extending in the axial direction, and a structure that supports the cylindrical body and can be expanded and contracted in the radial direction of the cylindrical body. A stent graft in which the tubular body is brought into close contact with the inner surface of a living body lumen to which the lumen is connected by expanding the structure, and a plurality of opening / closing portions connected to the lumen are provided on a side surface of the tubular body. The opening / closing part is closed when facing the inner surface of the biological lumen, and can be automatically opened when facing the branch lumen.

  According to the above, the plurality of opening / closing sections provided on the side surface of the cylindrical body are closed when facing the inner surface of the biological lumen, and can be automatically opened when facing the branch lumen. When a stent graft is placed in the vicinity of a biological lumen to which a branch lumen is connected, the cylindrical body is expanded (expanded) so that the opening / closing portion overlaps the branch lumen, and is locked to the biological lumen. Can do. Since the opening / closing part facing the branch lumen automatically opens, the flow path of the branch lumen is secured, and the fluid flowing in the living body lumen can be circulated favorably. That is, the stent graft having the opening / closing portion is easily locked without blocking the branch lumen without depending on the position of the healthy portion of the living body lumen. As a result, a procedure for placing the stent graft in the living body lumen can be performed efficiently, and the burden on the patient can be greatly reduced.

  In this case, a thread member that is sewn in the vicinity of the opening of the opening / closing portion that opens to the branch lumen and closes the opening, and the opening / closing portion is in a state in which the thread member is loosened, It can be configured to automatically open by being pressed toward the branch lumen by the fluid flowing through the lumen.

  In this way, by configuring the vicinity of the opening of the opening / closing portion with the thread member to close the mouth, a stent graft in which leakage of fluid from the side surface of the cylindrical body is prevented can be easily formed. Moreover, since the opening / closing part opens easily with respect to the branch lumen when the thread member is loosened, the communication state between the living body lumen and the branch lumen can be easily constructed.

  Further, a plurality of the opening / closing portions are provided side by side along the circumferential direction on the side surface of the cylindrical body, and the yarn member may be in a closed state by connecting the opening / closing portions arranged in the circumferential direction by one. .

  Thus, by connecting the opening and closing portions arranged in the circumferential direction by one thread member, the number of thread members provided in the stent graft can be reduced, and the stent graft can be formed more easily.

  In addition to the above configuration, it is preferable that the inner diameter of the thread member is set to be equal to or smaller than the inner diameter of the cylindrical body in the closed state of the opening / closing sections.

  Thereby, since the thread member is tensioned inside the cylindrical body, the opening and closing portions arranged in the circumferential direction are more reliably closed. Further, since the stent graft is pressed inward and contracted in diameter as it is locked to the living body lumen, the thread member stretched on the inner side of the cylindrical body is loosened. For this reason, the opening / closing part facing the branch lumen among the opening / closing parts arranged in the circumferential direction can be easily opened when pressed from the inside by the fluid.

  Here, the opening / closing portion is configured as a protruding cylindrical portion that protrudes from a side surface of the cylindrical body with an opening to the branch lumen, and the length of the side surface of the protruding cylindrical portion is equal to that of the protruding cylindrical portion. It may be longer than the radius of the opening.

  Thus, since the length of the side surface of the projecting tube portion is longer than the radius of the projecting tube portion, the side surfaces of the projecting tube portion can overlap each other with respect to the opening surface. It becomes possible to close the part reliably. Further, the projecting cylinder part projects to the root part of the branch lumen along with the opening, and can smoothly guide the fluid to the branch lumen.

  In addition, a plurality of the opening / closing portions are arranged side by side along the axial direction on the side surface of the cylinder, and the structure has a plurality of annular wires that can support the cylinder along the circumferential direction. The plurality of wire rods are preferably provided between the opening and closing portions adjacent in the axial direction.

  As described above, the wire constituting the structure is provided between the opening / closing parts adjacent in the axial direction, so that the structure does not overlap the opening of the opening / closing part. For this reason, the fluid can be circulated more smoothly in the branch lumen.

Further, the opening / closing part has the following shape when the opening opening to the branch lumen has a substantially circular shape, the diameter of the opening is φo, and the interval between the adjacent opening / closing parts is d. It is good to form so that the relationship of (1) Formula may be satisfy | filled.
5mm ≧ 2φo + d (1)

  That is, it is known that the diameter of the opening of the renal artery (branch lumen) where the stent graft is placed is about 5 mm. Therefore, when the stent graft is applied to the treatment of an abdominal aortic aneurysm, the opening / closing part can be reliably overlapped with the opening of the renal artery by forming the diameter of the opening / closing part so as to satisfy the relationship of the above formula (1). .

  In addition, as a method for treating an aneurysm using the stent graft described above, a cylindrical body having a lumen extending in the axial direction, and a structure that supports the cylindrical body and can be expanded and contracted in the radial direction of the cylindrical body are provided. A delivery step of using a stent graft in which a plurality of open / close portions connected to the lumen are provided on a side surface of the tubular body and delivering the tubular body and the structure to a living body lumen connected to a branch lumen with a reduced diameter state A distal end locking step for locking the distal end of the stent graft at a position above the branch lumen connection point, and an upper side of the abdominal aorta by expanding the upper side connected to the distal end of the stent graft. It is possible to adopt a method having an upper locking step in which the open / close part facing the healthy part and in close contact with the branch lumen is automatically opened.

  According to the present invention, when a stent graft is placed in the vicinity of a living body lumen to which a branching lumen is connected, while ensuring communication between the living body lumen and the branching lumen, Engagement is possible without depending on the position, so that the procedure can be performed efficiently and the burden on the patient associated with the treatment can be greatly reduced.

It is a whole lineblock diagram showing the stent graft concerning this embodiment. It is principal part explanatory drawing which shows the upper part side structure of the stent graft of FIG. 3A is an enlarged partial perspective view of the opening / closing part of FIG. 1, FIG. 3B is a plan sectional view of the opening / closing part of FIG. 3A, and FIG. 3C is an enlarged view of the opening / closing part of FIG. 3A. FIG. 3D is a plan sectional view of the opening / closing part of FIG. 3C. 4A is a schematic plan cross-sectional view showing the cylindrical graft at a position where the opening / closing part of FIG. 1 is formed, and FIG. 4B is a schematic front view showing a part of the cylindrical graft and the opening / closing part of FIG. 4A. 4C is a schematic plan sectional view showing a state in which the cylindrical graft of FIG. 4A faces the renal artery, and FIG. 4D is a schematic front view showing a part of the cylindrical graft and the opening / closing part of FIG. 4C. . FIG. 5A is a configuration diagram of an opening / closing portion according to the first configuration example, FIG. 5B is a configuration diagram of the opening / closing portion according to the second configuration example, and FIG. 5C is a closure of the opening / closing portion according to the third configuration example. 5D is a configuration diagram showing an opening state of the opening / closing portion of FIG. 5C, and FIG. 5E is a configuration diagram showing a closing state of the opening / closing portion according to the fourth configuration example. 5F is a configuration diagram illustrating an opening state of the opening / closing portion of FIG. 5E, FIG. 5G is a configuration diagram illustrating a closing state of the opening / closing portion according to the fifth configuration example, and FIG. 5H is a diagram of the opening / closing portion of FIG. It is a block diagram which shows an opening state. FIG. 6A is a first cross-sectional view illustrating a method for using a stent graft, and FIG. 6B is a second cross-sectional view illustrating a method for using a stent graft. FIG. 7A is a third cross-sectional view illustrating a method for using a stent graft, and FIG. 7B is a fourth cross-sectional view illustrating a method for using a stent graft. 8A is a cross-sectional view illustrating an application example of a stent graft, FIG. 8B is a cross-sectional view taken along the line VIIIB-VIIIB in FIG. 8A, and FIG. 8C is a cross-sectional view showing a state where the diameter of the stent in FIG. It is. It is sectional drawing which shows the whole structure of the stent graft which concerns on a modification.

  Hereinafter, the stent graft according to the present invention will be described in detail with reference to the accompanying drawings by giving preferred embodiments in relation to the treatment method using the stent graft.

  FIG. 1 is an overall configuration diagram showing a stent graft 10 according to the present embodiment. The stent graft 10 according to the present embodiment is an abdominal aortic aneurysm (hereinafter referred to as “abdominal aortic aneurysm”) generated in the abdominal aorta 100 (biological lumen) by an intravascular interventional technique (a technique for delivering the stent graft 10 to an abnormal site through the blood vessel) It is configured as an intraluminal implant for treating 102. The aneurysm 102 is formed, for example, in a spindle shape (or sac shape) at a location below the connection location of the renal artery 104 (location branched from the abdominal aorta 100) and above the common iliac artery 106. . The stent graft 10 is preferably used for the treatment of such an aneurysm 102.

  As shown in FIG. 1, the stent graft 10 is formed in a substantially Y shape as a whole, a tubular graft 12 that can be brought into close contact with the blood vessel wall 100 a of the abdominal aorta 100, and a stent 14 that supports the tubular graft 12 so that it can expand and contract. (Structure). A plurality of opening / closing portions 18 communicating with the lumen 16 (see FIG. 2) inside the cylindrical graft 12 are provided on the upper side surface of the cylindrical graft 12.

  Stent graft 10 is placed in abdominal aorta 100 by treatment of aneurysm 102. In this case, one end (upper end portion) of the stent graft 10 is inserted and locked to a position above the connection point of the renal artery 104 above the aneurysm 102. As a result, the stent graft 10 is securely locked to the upper healthy portion 108 of the abdominal aorta 100, and the opening / closing part 18 facing the renal artery 104 is automatically opened by blood to communicate the abdominal aorta 100 and the renal artery 104. Let Hereinafter, each configuration of the stent graft 10 will be specifically described.

  The cylindrical graft 12 is formed in a long and flexible cylindrical member (tubular body), and is bifurcated at an intermediate position in the axial direction (substantially intermediate position in the vertical direction in FIG. 1). . Specifically, the main body tube 20 that extends upward with the connecting portion C shown in FIG. 1 as a base point, and two branch tubes that extend to the lower portion of the connecting portion C and that extend to the lower portion of the main body tube 20 (first It is constituted by a branch tube 22 and a second branch tube 24). The main body tube 20 is formed to have a relatively large diameter so as to be in close contact with the blood vessel wall 100a of the abdominal aorta 100 from the inside. The first and second branch tubes 22 and 24 are formed to have a smaller diameter than the main body tube 20.

  The material constituting the cylindrical graft 12 is not particularly limited, but is formed from a biocompatible woven fabric, non-woven fabric, porous sheet, or other graft material (blood impervious material). It is preferable. Examples of the material having biocompatibility include artificial materials such as polyester fiber, ePTFE (expanded polytetrafluoroethylene), and polyurethane.

  The total length of the cylindrical graft 12 may be appropriately selected according to the shape of the living body lumen to be treated, the medical condition, and the like. For example, when used for the treatment of the abdominal aortic aneurysm 102, the total length of the tubular graft 12 may be set to about 120 to 280 mm.

  A lumen 16 (see FIG. 2) extending in the axial direction is formed inside the tubular graft 12. The lumen 16 is formed in a substantially Y shape according to the shape of the cylindrical graft 12, and an upper end opening 20 a formed at the upper end of the main body tube 20 and a first lower end opening 22 a formed at the lower end of the first branch tube 22. And the second lower end opening 24a formed at the lower end of the second branch tube 24 communicates with each other.

  The main body tube 20 is a portion that is mainly inserted into the abdominal aorta 100 (including the site where the aneurysm 102 occurs). Specifically, the upper end portion of the main body tube 20 is positioned in the upward direction beyond the connection point of the renal artery 104, so that the upper body portion 20b of the main body tube 20 is connected to the upper healthy portion 108 of the abdominal aorta 100. (The upper healthy part 108 includes the connection part of the renal artery 104). On the other hand, the lower end portion (connecting portion C) of the main body tube 20 is disposed near the upper portion of the common iliac artery 106. That is, the main body tube 20 extends from the upper healthy part 108 of the abdominal aorta 100 to the lower part of the site where the aneurysm 102 is generated, and smoothly flows blood flowing in the abdominal aorta 100 to the first and second branch tubes 22 and 24. Acts as a guiding barrier.

  The inner diameter φG (see FIG. 4A) of the body tube 20 is formed larger than the inner diameter φA (see FIG. 4C) of the living body lumen (abdominal aorta 100) to be treated. When the stent graft 10 is used for the treatment of the abdominal aortic aneurysm 102, it is preferably set to about 20 to 36 mm. For example, when the inner diameter φA of the abdominal aorta 100 is 25 mm, the inner diameter φG of the main body tube 20 is set to 30 mm. Good. Thereby, the side surface of the main body tube 20 is reliably brought into close contact with the blood vessel wall 100a of the abdominal aorta 100 (upper side healthy site 108).

  The first and second branch tubes 22 and 24 are inserted into the two common iliac arteries 106 connected to the downstream side of the abdominal aorta 100 by extending separately from the lower portion of the main body tube 20. It is a part. The lower regions 22c and 24c of the first and second branch tubes 22 and 24 have outer diameters that are gradually increased in the outer direction compared to the body portions 22b and 24b extending in the axial direction. Accordingly, the lower regions 22c and 24c of the first and second branch tubes 22 and 24 can be satisfactorily locked to the common iliac artery 106 (lower healthy portion 110).

  The inner diameters of the lower ends (lower regions 22c and 24c) of the first and second branch tubes 22 and 24 are preferably set to about 8 to 28 mm when used for the treatment of the abdominal aortic aneurysm 102, for example.

  The cylindrical graft 12 is usually formed integrally with the main body tube 20 and the first branch tube 22, but the second branch tube 24 can be separated at a connection position 25 close to the connection portion C (that is, separate). Body). In the stent graft 10, the main branch tube 20 and the first branch tube 22 are deployed in the abdominal aorta 100 and one common iliac artery 106a, and the second branch tube 24 configured as a separate body is replaced with the other common iliac artery. By being delivered from 106b and deployed at the connection position 25, it is configured in a substantially Y shape.

  The stent 14 that supports the tubular graft 12 has a first outer diameter that can be accommodated in the sheath 26 (see FIG. 6A) and is not inserted into the living body lumen (abdominal aorta 100) but is deployed outside the sheath 26. It is configured to be deformable to a second outer diameter (see FIG. 4A) that is larger than the first outer diameter in the natural state. Further, when the stent graft 10 is deployed in the abdominal aorta 100, the stent 14 is pushed inward by the blood vessel wall 100a, so that the stent 14 has a third outer diameter smaller than the second outer diameter in the natural state (FIG. 4C). See).

  The stent 14 is configured by arranging a plurality of annular wires (strands 28) supporting the cylindrical graft 12 in the circumferential direction along the axial direction of the cylindrical graft 12.

  The strand 28 is formed (shape memory) so as to loop in a straight line taking the second outer diameter in the natural state. Therefore, the stent 14 is elastically supported so that the tubular graft 12 is in an expanded state in a natural state. When the stent graft 10 is accommodated in the sheath 26, each strand 28 is elastically deformed in a wave shape along the circumferential direction to have a first outer diameter. Following this, the tubular graft 12 is also in a contracted state (first outer diameter). When released from the sheath 26, each strand 28 is elastically restored (self-expanding) so as to have the second outer diameter, and the tubular graft 12 is also deformed into an expanded state.

  Therefore, it is preferable that the strand 28 is made of a material having a sufficient elastic force. Examples of the material constituting the strand 28 include various metals such as stainless steel, Ni—Ti alloy, Cu—Zn alloy, Ni—Al alloy, tungsten, tungsten alloy, titanium, titanium alloy, tantalum, polyamide, polyimide, Examples include relatively high-rigidity polymer materials such as ultrahigh molecular weight polyethylene, polypropylene, and fluorine-based resins, or combinations of these appropriately. Further, by configuring the strand 28 so as to have X-ray contrast properties, the stent graft treatment can be favorably performed based on X-ray imaging.

  The second outer diameter of the stent 14 is appropriately set according to the site of the cylindrical graft 12 (main body tube 20, first and second branch tubes 22, 24). For example, the stent 14 a that supports the main body tube 20 is formed to have a larger outer diameter than the stent 14 b that supports the first and second branch tubes 22 and 24. The stent 14b that supports the first and second branch tubes 22 and 24 is a strand along the lower regions 22c and 24c (the shape that expands toward the lower end) of the first and second branch tubes 22 and 24. The outer diameter of 28 is set so as to gradually increase.

  The stent 14 is not limited to the above-described structure, and can adopt various configurations that can support the tubular graft 12 so as to be physically expandable and contractible. For example, a stent that is continuous in a substantially Z shape along the circumferential direction of the tubular graft 12, or a stent that is continuous in a wave shape along the circumferential direction of the tubular graft 12 may be employed. Furthermore, the stent 14 may adopt not only a structure that deforms to the second outer diameter by self-expanding from the first outer diameter but also a structure that expands with an expansion device (such as a balloon).

  As described above, the stent graft 10 includes a plurality of opening / closing portions 18 on the upper side surface of the tubular graft 12 (main body tube 20). Each opening / closing part 18 is closed in a state where the stent 14 has the second outer diameter and the tubular graft 12 is expanded (natural state). When the stent graft 10 is inserted into the abdominal aorta 100 and placed as a third outer diameter, the open / close portion 18 facing the side surface of the abdominal aorta 100 remains closed, but the renal artery 104 (branch lumen). The opening / closing part 18 facing the door automatically opens. Hereinafter, the configuration of the opening / closing part 18 will be described in detail.

  FIG. 2 is a main part explanatory view showing an upper side structure of the stent graft 10 of FIG. 3A is an enlarged partial perspective view of the opening / closing part 18 of FIG. 1, FIG. 3B is a plan sectional view of the opening / closing part 18 of FIG. 3A, and FIG. 3C is an opening of the opening / closing part 18 of FIG. FIG. 3D is a partial perspective view showing an enlarged state, and FIG. 3D is a plan sectional view of the opening / closing part 18 of FIG. 3C. 4A is a schematic plan cross-sectional view showing the cylindrical graft 12 at a position where the opening / closing part 18 of FIG. 1 is formed, and FIG. 4B is a schematic showing a part of the cylindrical graft 12 and the opening / closing part 18 of FIG. 4A. 4C is a schematic plan cross-sectional view showing a state in which the tubular graft 12 of FIG. 4A faces the renal artery 104, and FIG. 4D shows one of the tubular graft 12 and the opening / closing part 18 of FIG. 4C. It is a schematic front view which shows a part.

  As shown in FIG. 2, the plurality of opening / closing portions 18 are arranged in a matrix on the surface of the tubular graft 12 by being arranged along the circumferential direction and the axial direction of the tubular graft 12. The formation region M of the opening / closing portions 18 arranged in a matrix may enter the aneurysm 102 from the upper healthy portion 108. For this reason, the axial direction (vertical direction) length of the formation region M is set to be relatively long (for example, about 10 to 60 mm). Of course, the formation region M may be set to a length that does not cover the knob 102.

  As shown in FIG. 3C, the opening / closing portion 18 is formed in a cylindrical shape that protrudes outward from the side surface of the cylindrical graft 12 (hereinafter also referred to as a protruding cylindrical portion 30). The protruding cylindrical portion 30 can be made of the same material as the cylindrical graft 12 and is preferably integrally formed (continuously provided) with the cylindrical graft 12. A hollow portion 32 extending in the axial direction is provided inside the protruding cylindrical portion 30, and this hollow portion 32 is connected to the lumen 16 at the base end portion 34 of the protruding cylindrical portion 30, and the protruding end of the protruding cylindrical portion 30. The opening 38 formed on the side of the portion 36 is in communication with the lumen 16.

  As shown in FIGS. 2 to 3D, the protruding cylinder portion 30 is configured such that the opening 38 on the protruding end portion 36 side is closed by the thread member 40. That is, the thread member 40 is stitched so as to alternate between the outer surface and the inner surface in the vicinity of the projecting end portion 36, and has a stitched portion 42 that substantially goes around the side surface of the projecting cylindrical portion 30 in the circumferential direction. Forming. The upper end of the protruding cylindrical portion 30 terminates in the sewn portion 42, and a pair of thread members 40 are inserted into the hollow portion 32 from the end and guided into the lumen 16. Therefore, when the pair of thread members 40 are drawn toward the inner side (axial center side) of the tubular graft 12 (lumen 16), the circumferential length of the thread member 40 of the stitched portion 42 is shortened, and the protruding end portion 36 is the opening portion. Gather in the center of 38. As a result, the opening 38 of the protruding cylinder 30 is closed in a purse-like shape.

  Here, the protruding cylinder part 30 is formed such that the axial length L extending from the cylindrical graft 12 is longer than the radius R of the opening 38 of the protruding cylinder part 30 (see FIG. 3D). For this reason, the protruding end portion 36 is pulled toward the proximal end portion 34 by the thread member 40, so that the protruding end portions 36 are moved toward the proximal end portion 34 side while the inner surfaces are close to the axis of the protruding cylindrical portion 30. Moving. When pulled further toward the inside (axial side) of the tubular graft 12, the projecting end 36 closes (closes) the opening 38 in a liquid-tight manner and enters the lumen 16 via the hollow portion 32. Therefore, as shown in FIGS. 3A and 3B, a state is formed in which the protruding end portion 36 extending from the base end portion 34 of the protruding cylindrical portion 30 is positioned in the lumen 16.

  The axial length L of the protruding cylindrical portion 30 may be set sufficiently shorter than the inner diameter of the cylindrical graft 12. For example, when the inner diameter φG of the cylindrical graft 12 (main body tube 20) is set to 30 mm, the axial length L of the protruding cylindrical portion 30 is set to about 1 mm.

  Further, the pair of thread members 40 extending from the end of the sewn portion 42 are respectively directed to the protruding cylindrical portions 30 and 30 adjacent in the circumferential direction (left and right direction), and the adjacent protruding cylindrical portions 30 and 30 have the same structure. As a result, the openings 38 are closed. That is, the thread member 40 extends in the circumferential direction along the inner surface of the cylindrical graft 12 and closes all the protruding cylindrical portions 30 that are arranged in parallel in the circumferential direction (row direction). In other words, as shown in FIG. 2 and FIG. 4A, the plurality of protruding cylindrical portions 30 (one row of opening / closing portions 18, 18,...) Arranged in the circumferential direction are connected to each other by a single thread member 40. In the front view of the cylindrical graft 12 (see FIG. 4B), all the protruding cylindrical portions 30 are closed.

  The thread member 40 is set so that its diameter φT is equal to or smaller than the inner diameter φG of the cylindrical graft 12 in a state where the opening / closing portion 18 (the protruding cylindrical portion 30) is closed and the inside of the cylindrical graft 12 is looped. For this reason, the thread member 40 supports the protruding end portions 36 of the plurality of protruding cylindrical portions 30 arranged in the circumferential direction so as to be positioned in the lumen 16.

  Here, based on FIG. 4A and FIG. 4C, the relationship between the stent graft 10 and the abdominal aorta 100 (upper side healthy part 108) to which the upper side of the stent graft 10 is locked will be described in detail. In the stent graft 10, the inner diameter φG of the tubular graft 12 is set larger than the inner diameter φA of the upper healthy portion 108 in a state where the stent 14 is expanded to the second outer diameter (natural state). The diameter φT of the thread member 40 that loops the inner surface of the cylindrical graft 12 is set to be equal to or smaller than the inner diameter φG of the cylindrical graft 12 and larger than the inner diameter φA of the upper healthy portion 108. That is, the stent graft 10 is configured such that the relationship φG ≧ φT> φA is established in a natural state where the stent graft 10 is not locked to the abdominal aorta 100.

  When the stent graft 10 is locked to the upper healthy portion 108, the stent 14 larger than the inner diameter φA of the upper healthy portion 108 is pressed by the blood vessel wall 100a and reduced in diameter to the third outer diameter (locked state). Accordingly, the diameter of the cylindrical graft 12 is also reduced. Therefore, in the natural state, the thread member 40 that has been closed with the protruding end portion 36 in the lumen 16 is loosened.

  In the locked state of the stent graft 10, the tubular graft 12 is pressed outward by the blood flowing through the lumen 16, and comes into close contact with the blood vessel wall 100 a of the abdominal aorta 100. The opening / closing portion 18 facing the blood vessel wall 100a maintains the closed state even when the opening / closing portion 18 is pressed outward by blood.

  On the other hand, the opening / closing part 18 (projecting cylinder part 30) facing the renal artery 104 is pushed out into the renal artery 104 when the opening / closing part 18 is pressed outward by blood by the slack thread member 40. It is. Therefore, only the protruding cylindrical portion 30 facing the renal artery 104 is opened, and the lumen 16 and the renal artery 104 are communicated through the hollow portion 32.

  Next, based on FIG. 4D, the relationship between the opening / closing part 18 (projecting cylinder part 30) of the stent graft 10 and the renal artery 104 to which the opening / closing part 18 faces will be described in detail.

  The distances d1 and d2 between the opening / closing portions 18 arranged in the circumferential direction (column direction) and the axial direction (row direction) have such resistance and rigidity that the cylindrical graft 12 is not affected by the blood flowing through the lumen 16. As such, the dimensions may be set. Moreover, it is preferable that the distance d1 between the opening / closing parts 18 arranged in the circumferential direction and the interval d2 between the opening / closing parts 18 arranged in the axial direction are substantially equal. As a result, in the formation region M, the open / close portions 18 arranged evenly in the circumferential direction and the axial direction exist, and any open / close portion 18 is made to face the renal artery 104 having the substantially circular opening 104a. Becomes easy.

  Further, the opening / closing sections 18 arranged in the circumferential direction may be arranged so as not to overlap with the strands 28 arranged in the axial direction. For example, as shown in FIG. 2 and FIG. 4B, two rows of opening / closing portions 18 may be arranged between adjacent strands 28. As a result, each protruding cylindrical portion 30 is positioned in the vicinity of the strand 28, and is supported by the strand 28 so as to have sufficient tension when protruding outside the cylindrical graft 12 by blood.

  Furthermore, it is important to set the diameter (outer diameter) φo of the opening 38 of the opening / closing part 18 (projecting cylinder part 30) to be smaller than the inner diameter φr of the opening 104a of the renal artery 104. Usually, it is known that the inner diameter φr of the opening 104a of the renal artery 104 is about 5 mm. Therefore, when the size of the opening / closing part 18 is set so that the relationship of 5 mm ≧ φo is established, the protruding cylinder part 30 Can be projected into the renal artery 104.

More preferably, the relationship between the diameter φo of the opening / closing portion 18 and the distance d (d = d1≈d2) may be set so as to satisfy the relationship of the following expression (1).
5mm ≧ 2φo + d (1)

  If it is set so as to satisfy the relationship of the expression (1), no matter how the stent graft 10 is arranged with respect to the abdominal aorta 100, the opening / closing part 18 is surely overlapped with the opening 104 a of the renal artery 104 and automatically opened. Can be made.

  The opening / closing unit 18 may employ various configurations other than the above configuration. For example, a configuration in which the opening / closing part 18 is physically engaged (hooked) and opened by applying blood pressure, or a structure in which the opening / closing part 18 is opened by some operation (for example, a device that can be inserted into the stent graft 10) is adopted. obtain. Hereinafter, some configuration examples of the other opening / closing sections will be described.

  The opening / closing part 18a according to the first configuration example shown in FIG. 5A is configured such that the protruding cylinder part 30 protruding from the cylindrical graft 12 is folded and a part of the protruding end part 36 overlaps at the center part of the opening / closing part 18a. Has been. A thread member 40 that loops through the lumen 16 is sewn into the overlapped portion 50 of the protruding end portion 36, and is exposed to the outer surface side of the opening / closing portion 18a. As described above, the folded opening / closing part 18a is also closed by the thread member 40 and is automatically opened when the thread member 40 is loosened and the blood is pressed by the blood, similarly to the opening / closing part 18 described above. Can do.

  The opening / closing part 18b according to the second configuration example shown in FIG. 5B is configured as a protruding cylindrical part 52 formed in a quadrangle in a front view, and is folded in the same manner as the opening / closing part 18a according to the first configuration example. The thread member 40 is sewn into the overlapping portion 50 of 52a. Even with the opening / closing part 18b configured as described above, the same operations and effects as those of the opening / closing parts 18 and 18a described above can be obtained. In short, the opening / closing part 18 may be any structure that blocks the blood flow in the closed state and allows the blood to flow in the open state, and the shape thereof is not particularly limited, and various shapes (for example, elliptical, polygonal, etc.) ) Can be taken.

  The opening / closing part 18 c according to the third configuration example shown in FIGS. 5C and 5D has a pair of movable pieces 56 around the opening 54 communicating with the lumen 16 of the cylindrical graft 12. The movable piece 56 is formed to be longer than the radius of the opening 54, and the overlapping portion 50 is formed at the center of the opening 54 by bringing the protruding end portions 56 a close to each other. Therefore, by sewing the thread member 40 into the protruding end portions 56a of the pair of movable pieces 56, the opening and closing portion 18c can obtain the same operations and effects as the above-described opening and closing portions 18, 18a, and 18b.

  The opening / closing part 18d according to the fourth configuration example shown in FIGS. 5E and 5F is configured by a slit 58 formed in the side surface of the tubular graft 12. When the slit 58 is located at the upper healthy portion 108 of the abdominal aorta 100, the closed state is maintained by contacting the blood vessel wall 100a, and when the slit 58 faces the opening 104a of the renal artery 104, blood pressure is applied. It opens automatically. Therefore, the renal artery 104 and the lumen 16 can be easily communicated with each other via the slit 58.

  The opening / closing part 18e according to the fifth configuration example shown in FIGS. 5G and 5H is configured by a check valve 60 provided on the side surface of the tubular graft 12. This check valve 60 can also obtain the same operation and effect as the slit 58 described above.

  Needless to say, the sewing portion 42 (that is, the sewing method) of the opening / closing portion 18 formed by the thread member 40 can take various configurations.

  The stent graft 10 according to the present embodiment is basically configured as described above, and its operation and effects will be described below. 6A is a first cross-sectional view illustrating a method of using the stent graft 10, FIG. 6B is a second cross-sectional view illustrating a method of using the stent graft 10, and FIG. 7A illustrates a method of using the stent graft 10. FIG. 7B is a fourth cross-sectional view for explaining how to use the stent graft 10.

  The stent graft 10 according to the present embodiment is suitably used for the treatment of an abdominal aortic aneurysm (aneurysm 102) that occurs in the abdominal aorta 100 as described above. The aneurysm 102 is formed by weakening the blood vessel wall 100a of the abdominal aorta 100 due to, for example, arteriosclerosis or the like, and the portion is pushed by the blood flow and gradually expands. The treatment target by the stent graft 10 is not limited to the abdominal aortic aneurysm 102 but can be applied to the treatment of an aneurysm that develops in a branched blood vessel (branch lumen) branched from the main blood vessel (biological lumen). is there. Examples of aneurysms include cerebral aneurysms, thoracic aortic aneurysms, coronary aneurysms, popliteal aneurysms, femoral aneurysms, carotid aneurysms, and the like. When the stent graft 10 is used for the treatment of these aneurysms, it is needless to say that the opening / closing part 18 needs to be disposed at an appropriate position on the side surface of the tubular graft 12.

  Here, the treatment method of the aneurysm 102 using the stent graft 10 will be schematically described. The tubular graft 12 and the stent 14 of the stent graft 10 are accommodated in the sheath 26 in a reduced diameter state (first outer diameter). The first step (delivery step) for delivering to the desired position of the abdominal aorta 100 by the above, the distal end of the stent graft 10 is exposed from the sheath 26 and expanded (expanded), thereby locking at the upper position of the connection point of the renal artery 104 A second step (tip locking step), and a third step (upper locking step) in which the upper side connected to the tip of the stent graft 10 is exposed from the sheath 26 and deployed to closely contact the upper healthy portion 108 of the abdominal aorta 100. ), A fourth step in which the lower side continuous with the upper side of the stent graft 10 is exposed from the sheath 26 and deployed. (Lower locking step), deploying the stent graft 10 so as to be placed in the abdominal aorta 100, locking the lower end of the stent graft 10 to the lower healthy portion 110 (the common iliac aorta), and A fifth step (detention step) of detaining 10 is sequentially performed. As a result, the stent graft 10 is placed in the abdominal aorta 100 so as to bypass the aneurysm 102. Hereinafter, each step will be described in detail.

[Delivery step]
In the delivery step, the surgeon incises a predetermined position (for example, buttocks) of the patient, and a delivery device 44 (for example, a catheter) having a sheath 26 on the distal end side is percutaneously inserted into the blood vessel from the incised portion. . As shown in FIG. 6A, the delivery device 44 has a nose cone 46 supported by a shaft 45 at the distal end, and includes a sheath 26 after the nose cone 46. Within the sheath 26, the stent graft 10 (the tubular graft 12 and the stent 14) is accommodated in a reduced state (first outer diameter).

  The surgeon advances and moves the delivery device 44 along a guide wire (not shown) that is previously inserted into the blood vessel. And the nose cone 46 is delivered so that the connection location of the renal artery 104 connected to the abdominal aorta 100 may be exceeded. As a result, the stent graft 10 accommodated in the sheath 26 is disposed such that the side surface in the accommodated state faces the upper healthy site 108, the occurrence site of the aneurysm 102, and the lower healthy site 110 of the abdominal aorta 100. .

[End locking step]
After the delivery step, a tip locking step is performed as shown in FIG. 6B. In the distal end locking step, the distal end of the stent graft 10 accommodated in the sheath 26 is exposed (released) by moving the sheath 26 backward while the delivery device 44 (nose cone 46) is positioned and fixed. Thereby, the distal end side strand 28 (stent 14a) is elastically expanded in diameter, and acts to press the supporting tubular graft 12 (main body tube 20) on the blood vessel wall 100a. Then, the strand 28 is pressed against the blood vessel wall 100a to become the third outer diameter, and the side surface of the tubular graft 12 is brought into close contact with the blood vessel wall 100a. That is, the distal end of the stent graft 10 is locked at the upper position of the connecting portion of the renal artery 104.

[Upper locking step]
After the tip locking step, an upper locking step is performed as shown in FIG. 7A. In the upper locking step, the sheath 26 is further moved backward to expose the upper side of the main body tube 20 to a position above the location where the aneurysm 102 is generated. The main body tube 20 is self-expanded by the stent 14 a and acts to press the side surface of the main body tube 20 against the blood vessel wall 100 a of the upper healthy portion 108. As a result, the upper side of the main body tube 20 is pressed by the opposing blood vessel wall 100a and becomes in contact with the blood vessel wall 100a as a third outer diameter.

  Here, the upper healthy site 108 includes a connection location (opening 104a) of the renal artery 104. Therefore, one (one or more) of the opening / closing portions 18 of the formation region M formed on the upper side of the stent graft 10 faces the opening 104 a of the renal artery 104. In addition, the thread member 40 having the opening / closing portion 18 in the closed state is in a loosened state compared with a state in which the main body tube 20 has a third outer diameter, and is looped in the circumferential direction. doing. For this reason, when the opening / closing part 18 (the protruding cylinder part 30) faces the renal artery 104, the protruding cylinder part 30 is pushed out toward the outside (ie, the renal artery 104) by the blood flowing in the lumen 16 of the stent graft 10. The opening 38 of the protruding cylinder 30 is opened.

  By opening the opening 38 in this manner, the lumen 16 and the renal artery 104 communicate with each other via the hollow portion 32 of the protruding cylindrical portion 30. Thereby, blood flowing through the lumen 16 is circulated into the renal artery 104 through the hollow portion 32.

[Lower locking step]
After the upper locking step, the lower locking step is performed as shown in FIG. 7B. In the lower locking step, the sheath 26 is further moved backward to expose the lower side of the main body tube 20 in the location where the knob 102 is generated. In this case, the main body tube 20 is self-expanded by the stent 14a, but since the knob 102 is formed in a spindle shape, the side surface of the main body tube 20 is not in contact with the blood vessel wall 100a. In this state, the lower side of the main body tube 20 has a second outer diameter and extends in the axial direction.

  That is, the formation region M of the main body tube 20 existing at a position facing the knob 102 is in a state where the thread member 40 closing the opening / closing portion 18 is stretched in the lumen 16. For this reason, the opening / closing part 18 is kept closed by the thread member 40. That is, even if a gap (space) exists between the inner surfaces of the tubular graft 12 and the aneurysm 102, the opening of the opening / closing part 18 is prevented. Therefore, the stent graft 10 can prevent blood from leaking into the aneurysm 102 (end leak), and can stably guide blood flowing in the lumen 16 to the downstream side.

[Detention step]
After the lower locking step, an indwelling step is performed. In the indwelling step, the main body tube 20 and the first branch tube 22 are expanded from the sheath 26, and the second branch tube 24 is separately delivered and connected to the connection position 25, thereby constructing the substantially Y-shaped stent graft 10. . The first and second branch tubes 22 and 24 are locked to the lower healthy portion 110 (the common iliac artery 106) by expanding the diameter of the stent 14b (see FIG. 1).

  After the stent graft 10 is deployed in the abdominal aorta 100 (and the common iliac artery 106), the delivery device 44 is moved backward and removed from the blood vessel, so that only the stent graft 10 is placed in the abdominal aorta 100. In the indwelling state of the stent graft 10, blood flowing through the abdominal aorta 100 is bypassed by the stent graft 10, and blood leakage to the aneurysm 102 is prevented. Therefore, the aneurysm 102 is in a contracted state with a thrombus formed in the long term.

  8A is a cross-sectional view illustrating an application example of the stent graft 10, FIG. 8B is a cross-sectional view taken along the line VIIIB-VIIIB in FIG. 8A, and FIG. 8C shows a state in which the diameter of the stent 70 in FIG. It is sectional drawing.

  By the way, the knob 102 is formed in various shapes according to a medical condition or the like. For this reason, as shown in FIG. 8A, when the aneurysm 102 has a distorted shape, when the stent graft 10 is inserted into the aneurysm 102, the tubular graft 12 is pressed against the blood vessel wall 100a, and the diameter expansion state changes in the aneurysm 102. Sometimes. As described above, when the expanded diameter state is deformed, the thread member 40 may be loosened, and the opening / closing part 18 (the protruding cylinder part 30) may be opened.

  Therefore, in order to repair the opening of the opening / closing part 18, in the treatment method using the stent graft 10 according to the present embodiment, a separately prepared stent 70 may be deployed inside the stent graft 10. Specifically, as shown in FIGS. 8A and 8B, after the stent graft 10 is deployed, the stent 70 is delivered to the inside of the opening portion of the opening / closing part 18 (projecting cylinder part 30). Then, as shown in FIG. 8C, the diameter of the stent 70 is expanded and brought into close contact with the inner surface of the tubular graft 12. Since the diameter of the thread member 40 is increased by the expanded stent 70, the thread member 40 shifts from a relaxed state to a tensioned state in the lumen 16. That is, the protruding cylindrical portion 30 that has been opened due to the slack of the thread member 40 can be pulled inward, and the opening 38 can be closed.

  Instead of the stent 70, a stent graft (not shown) having the same diameter as the stent 70 may be delivered and deployed so that the opening of the opening / closing part 18 is simply closed. Further, when the tubular graft 12 is deployed in the abdominal aorta 100, the thread member 40 may be loosened, and the opening / closing portion 18 (the protruding tubular portion 30) may be opened. In this case, by using a balloon or the like (not shown) and expanding within the tubular graft 12, the thread member 40 can be re-tensioned and the opening / closing part 18 can be closed.

  As described above, according to the stent graft 10 according to the present embodiment, the plurality of opening / closing portions 18 provided on the side surface of the tubular graft 12 are closed when facing the blood vessel wall 100a of the abdominal aorta 100, and the renal artery 104 is closed. Open automatically when facing. Therefore, when treating the aneurysm 102 by stent graft treatment, the tubular graft 12 can be expanded (expanded) so that the opening / closing portion 18 overlaps the renal artery 104 and can be locked to the upper healthy portion 108. Since the opening / closing part 18 facing the renal artery 104 automatically opens, the flow path of the renal artery 104 is secured, and blood can be circulated favorably through the renal artery 104. That is, the stent graft 10 can be easily locked to the abdominal aorta 100 without depending on the position of the landing zone (healthy site) that has been conventionally required on the lower side of the renal artery 104 and without blocking the renal artery 104. Is done. Thereby, the stent graft treatment (insertion) can be efficiently performed, and the burden on the patient can be greatly reduced.

  Moreover, the stent graft 10 can be easily formed by adopting a configuration in which the vicinity of the opening portion 38 of the protruding cylindrical portion 30 is sewn and closed by the thread member 40. Since the protruding cylindrical portion 30 is easily opened to the renal artery when the thread member 40 is loosened, the abdominal aorta 100 and the renal artery 104 can be easily communicated with each other.

  Furthermore, by connecting the open / close portions 18 arranged in the circumferential direction of the tubular graft 12 by one thread member 40, the number of thread members 40 provided in the stent graft 10 can be reduced, and the stent graft 10 can be more easily made. Can be formed.

  Still further, the axial length L of the protruding cylindrical portion 30 configured as the opening / closing portion 18 is longer than the radius R of the opening 38 of the protruding cylindrical portion 30, so Since they can be overlapped with each other, the opening 38 can be reliably closed. In addition, since the protruding cylindrical portion 30 protrudes to the root portion of the renal artery 104 with the opening, blood can be prevented from entering between the cylindrical graft 12 and the blood vessel wall 100a, so that blood can smoothly enter the renal artery 104. Can lead.

  In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Needless to say.

  The stent graft is not limited to a substantially Y-shape, and can take various shapes. For example, as shown in FIG. 9, when the aneurysm 102 is formed at a position close to the connection site of the renal artery 104, and a sufficiently long lower healthy site 110 exists between the aneurysm 102 and the common iliac artery 106. May apply a stent graft 10A extending linearly.

DESCRIPTION OF SYMBOLS 10 ... Stent graft 12 ... Cylindrical graft 14 ... Stent 16 ... Lumen 18 ... Opening / closing part 28 ... Strand 30 ... Projection cylinder part 36 ... Projection end part 38 ... Opening part 40 ... Thread member 100 ... Abdominal aorta 104 ... Renal artery 108 ... Upper part Side healthy part 110 ... Lower side healthy part

Claims (7)

A cylindrical body having a lumen extending in the axial direction, and a structure that supports the cylindrical body and is capable of expanding and contracting in the radial direction of the cylindrical body, and is provided on the inner surface of a living body lumen to which a branch lumen is connected On the other hand, a stent graft in which the tubular body is brought into close contact by expansion of the structure,
A plurality of opening / closing portions connected to the lumen are provided on a side surface of the cylindrical body,
The stent graft according to claim 1, wherein the opening / closing part is closed when facing the inner surface of the living body lumen, and can be automatically opened when facing the branching lumen. The stent graft of claim 1,
A thread member that is sewn in the vicinity of the opening of the opening / closing portion that opens into the branch lumen, and closes the opening;
The stent graft according to claim 1, wherein the opening / closing portion is automatically opened by being pressed toward the branch lumen by a fluid flowing through the lumen in a state where the thread member is loosened. The stent graft of claim 2,
A plurality of the opening / closing portions are arranged side by side along the circumferential direction on the side surface of the cylindrical body,
The stent graft characterized in that the thread member is in a closed state by connecting each opening and closing part arranged in the circumferential direction by one. The stent graft of claim 3,
The stent graft according to claim 1, wherein an inner diameter of the thread member is set to be equal to or smaller than an inner diameter of the cylindrical body in a closed state of the opening / closing portions. In the stent graft according to any one of claims 1 to 4,
The opening / closing portion is configured as a protruding cylindrical portion that protrudes from a side surface of the cylindrical body with an opening to the branch lumen,
The length of the side surface of the protruding cylinder part is longer than the radius of the opening of the protruding cylinder part. In the stent graft according to any one of claims 1 to 5,
A plurality of the opening / closing portions are arranged in parallel along the axial direction on the side surface of the cylindrical body,
The structure is configured by arranging a plurality of annular wires that can support the cylindrical body in the circumferential direction,
The stent graft, wherein the plurality of wires are provided between the opening and closing portions adjacent in the axial direction. In the stent graft according to any one of claims 1 to 6,
The opening / closing part has the following shape when the opening opening to the branch lumen has a substantially circular shape, the diameter of the opening is φo, and the distance between the adjacent opening / closing parts is d: 1) A stent graft formed so as to satisfy the relationship of the formula:
5mm ≧ 2φo + d (1)

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