A coated stent

Abstract

The present invention provides a stent graft, comprising a proximal end closed area, a concave guide area and a distal end closed area arranged in sequence, the proximal end closed area and the distal section closed area are provided with a plurality of closed rings, the concave guide area is provided with a plurality of guide rings, the coating is attached to the closed rings and the guide rings, the guide ring comprises: a support ring and a concave ring, the concave ring comprises a flat band and a normal band, the support ring is connected to the concave ring and is located outside the flat band, the coating is concave inwardly along the circumference of the local area of ​​the stent graft and attached to the flat band to form a concave coating. The concave ring of the present invention can fix the free concave coating while maintaining its concave shape, preventing the concave coating and the pre-opening from being displaced by the impact of blood flow, the support ring has a supporting function, and the short wave rod connected to the concave ring can effectively enhance the stability of the long wave rod, which can reduce the difficulty of the doctor's operation.

Description

Technical Field

[0001] The invention relates to medical devices, and in particular to a coated stent. Background Art

[0002] Aortic dissection (AD) refers to a disease in which the intima and media of the aortic lesion are separated. Endovascular repair is a minimally invasive interventional treatment. In the process of using endovascular repair to treat aortic dissection, the blood vessel is punctured percutaneously and a specific delivery device is used to release an artificial tubular prosthesis (i.e., covered stent) at the site of the lesion. The artificial prosthesis is used to seal the ruptured vascular intima, rebuild a new blood channel, and isolate the impact of aortic high-pressure blood flow on the lesion area, thereby achieving the treatment of aortic dissection. Endovascular repair is less invasive than open surgery and has the advantages of better long-term aortic remodeling than conservative treatment.

[0003] The aortic arch is the arch-shaped part of the upper part of the aorta, and there are three larger arterial branches on the large bend side. From the proximal end to the distal end of the aorta, the three major branch vessels are the innominate artery, the left common carotid artery, and the left subclavian artery. When performing endovascular treatment for aortic dissection involving the aortic arch, the stent graft needs to cover and cross the aortic arch.

[0004] When using traditional covered stents to repair aortic dissection, the existing "pre-opening covered stent" technology, which pre-opens a hole on the film surface of the covered stent. After the covered stent is implanted into the aortic arch, the "pre-opening" and the "branch vessel" are aligned one by one, and the "branch stent" is implanted between the "branch vessel" and the "pre-opening" to achieve the purpose of restoring blood supply to the branch vessel. There is also the "pre-opening covered stent + concave opening area covering" technology, in which part of the film of the covered stent is designed to be concave, and a pre-opening operation is performed on the concave film surface to achieve the purpose of increasing the "operating space for implanting the 'branch stent'".

[0005] The above technology has the following defects:

[0006] The "concave coating" is not supported by the stent ring and is easily deformed after being impacted by high-pressure blood flow. In this type of technology, the stent ring of the coated stent is circular in the circumferential direction. The film in the opening area is partially attached to the stent ring in the circumferential direction. The other part of the film in the circumferential direction is not connected to the stent ring, and the film is free and drooping in the stent ring, thereby forming a "D"-shaped or saddle-shaped "concave coating" shape.

[0007] After being impacted by the high-speed and periodic blood flow ejected by the heart, the free "concave membrane" will oscillate and deform in the blood vessels, and the "pre-opening" on the "concave membrane" will also oscillate and deform accordingly, which will reduce the size of the "concave opening area", reduce the operating space for implanting the branch stent, and increase the difficulty of positioning and releasing the branch stent.

[0008] And the "concave coating" is supported by a stent ring with a large opening angle, high wave height, and a "D" shape or saddle shape. However, the "concave coating" is still easily deformed after being impacted by high-pressure blood flow. In this type of technology, two types of stents are set in the opening area of ​​the coated stent: a "D"-shaped or saddle-shaped stent ring and a circular stent ring, and the two types of stent rings are arranged alternately. The film in the opening area is completely attached to the "D"-shaped or saddle-shaped stent ring in the circumferential direction, thereby forming the shape of a "concave coating".

[0009] The "D"-shaped or saddle-shaped stent is used to maintain the "concave" shape of the coating to resist the impact of high-speed blood flow. However, in order to avoid the "pre-opening" on the "concave coating" and prevent interference with the release of the branch stent, the flat wave angle of the "D"-shaped or saddle-shaped stent is large and the stent rod is long. According to material mechanics knowledge such as pressure rod stability, the "D"-shaped or saddle-shaped stent at this time has poor stability and is still easy to deform after being impacted by high-pressure blood flow, and the effect of maintaining the "concave" shape of the coating is poor. Summary of the invention

[0010] In view of this, the main purpose of the present invention is to provide a coated stent to reduce the difficulty of operation for doctors.

[0011] In order to achieve the above-mentioned and other related purposes, the present invention provides a stent graft.

[0012] It comprises a proximal end closed area, a concave guide area and a distal end closed area which are arranged in sequence, wherein the proximal end closed area and the distal end closed area are provided with a plurality of closed rings, the concave guide area is provided with a plurality of guide rings, the coating is attached to the closed rings and the guide rings, and the guide rings comprise:

[0013] A support ring and a concave ring, the concave ring includes a flat band and a normal band, the support ring is connected to the concave ring and is located on the outside of the flat band, the coating is recessed inward along its circumference in a local area of ​​the coating support and attached to the flat band of the concave ring to form a concave coating, and a temporary operating space is formed between the concave coating and the support ring on its outside.

[0014] In one embodiment of the present invention, the concave ring is circular and wavy along the circumferential direction, and the number of troughs or peaks of the concave ring is at least four.

[0015] In one embodiment of the present invention, the support ring is arc-shaped and wavy along the circumferential direction, and the number of wave troughs or wave peaks of the support ring is at least two.

[0016] In one embodiment of the present invention, two ends of the support ring are fixedly connected to two ends of the flat band through a connecting tube to form a double-layer structure with the concave ring.

[0017] In one embodiment of the present invention, the support ring and the concave ring are both made of metal wires, the cross-section of the metal wires is circular or square, and the diameter of the circle or the diameter of the circumscribed circle of the square is set between 0.1 mm and 1 mm.

[0018] In one embodiment of the present invention, the connecting tube is a hollow metal tube, the length of which is set between 1 mm and 10 mm, and the inner diameter of the tube cavity is greater than or equal to the sum of the metal wire diameters of the concave ring and the support ring.

[0019] In one embodiment of the present invention, two ends of the support ring are directly and fixedly connected to two ends of the flat band by welding, sewing or hot melting, so as to form a double-layer structure with the concave ring.

[0020] In one embodiment of the present invention, the closing ring, the supporting ring and the recessed ring are formed by cutting metal pipes or by 3D metal printing.

[0021] In one embodiment of the present invention, the axial length of the support ring is set between 5 mm and 30 mm, and the arc diameter of the support ring is set between 20 mm and 50 mm.

[0022] In one embodiment of the present invention, the closed ring is circular and wavy along the circumference, and the number of troughs or peaks of the closed ring is at least three.

[0023] In one embodiment of the present invention, the axial length of the closed ring is set between 10 mm and 40 mm, and the diameter of the closed ring is set between 20 mm and 50 mm.

[0024] In one embodiment of the present invention, the support ring is an annular structure, including a supporting flat band and a supporting normal band. The flat band of the concave ring and the supporting flat band are both connected to the coating to fix the support ring and the concave ring. The coating is attached to the supporting flat band to form a concave coating.

[0025] In one embodiment of the present invention, the supporting flat band is fixedly connected to the concave covering membrane by sewing or hot melting.

[0026] In one embodiment of the present invention, a pre-opening is provided on the concave covering film located in the concave guide area, and the pre-opening is located in the middle of the opening angle of the flat band.

[0027] In one embodiment of the present invention, the diameter of the distal end closed area gradually decreases or remains unchanged along the direction from one end close to the concave guide area to the other end.

[0028] In one embodiment of the present invention, the coating is attached to the surface of the closed ring and part of the surface of the guide ring by sewing or hot melting, and the coating is a flexible film.

[0029] In one embodiment of the present invention, the coating is attached to the inner surface or the outer surface or the inner and outer surfaces of the concave ring, and the coating is not attached to the inner and outer surfaces of the support ring.

[0030] The present invention proposes a coated stent, wherein a support ring can support the tubular shape of a concave guide area, and a flat band of the concave ring can fix a free "concave coating" while maintaining its concave shape, thereby preventing the concave coating and the pre-opening from being displaced by blood flow impact.

[0031] The present invention provides a stent graft, wherein the support ring has the function of closed ring support, and the short wave rod connected to the concave ring can effectively enhance the stability of the long wave rod. In addition, in other embodiments, the flat wave of the support ring is connected to the graft, which can directly fix and maintain the concave shape of the graft.

[0032] The covered stent described in the present invention has the advantage of treating aortic arch dissection. After a dissection occurs in a blood vessel, the false lumen gradually increases and the true lumen gradually decreases. Clinical studies have shown that when a dissecting blood vessel receives interventional treatment with a covered stent, the blood in the false lumen is gradually absorbed, the axial cross-section of the false lumen gradually decreases, and the size of the true lumen is restored. When the covered stent described in the present invention is implanted in a dissecting aortic arch, the flat wave of the guide ring is squeezed by the false lumen and cannot be completely released and is radially concave inward, increasing the exposed space of the concave guide area, further increasing the entry space for the branch stent guide wire, and reducing the difficulty of releasing the branch stent. When the blood in the false lumen is absorbed, the flat wave is also released and expanded, and the size of the true lumen of the blood vessel reconstructed by the covered stent is restored. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0034] Figure 1Schematic diagram of the structure of a stent graft in one embodiment of the present invention.

[0035] Figure 2 Schematic diagram of the structure of a side view of a coated stent in one embodiment of the present invention.

[0036] Figure 3 Schematic diagram of the structure of the diversion area in the stent graft in one embodiment of the present invention.

[0037] Figure 4 Schematic diagram of using a branch stent to close the pre-opening and reconstruct the branch vessel lumen.

[0038] Figure 5 Schematic diagram of the structure of a closed ring in a stent graft in one embodiment of the present invention.

[0039] Figure 6 FIG. 1 is a schematic structural diagram of a closed loop side view in one embodiment of the present invention.

[0040] Figure 7 Schematic diagram of the structure of a guide ring in a stent graft in one embodiment of the present invention.

[0041] Figure 8 It is a schematic structural diagram of a guide ring in a side view in one embodiment of the present invention.

[0042] Fig. 9 Schematic diagram of the structure of the concave ring in the guide ring in one embodiment of the present invention.

[0043] Fig.10 The figure is a schematic diagram of the structure of a support ring in a guide ring in one embodiment of the present invention.

[0044] Fig.11 FIG. 4 is a schematic structural diagram of a support ring in another embodiment of the present invention.

[0045] Fig.12 for Figure 3 Schematic diagram of the enlarged structure at G in the middle.

[0046] Fig.13 Schematic diagram of a stent graft for treating aortic arch dissection in one embodiment of the present invention.

[0047] Description of labels:

[0048] Stent graft 1; closure ring 10; flow guide ring 11; support ring 111; first connecting rod 1110; support flat band 1111; support normal band 1112; coating 12; concave coating 121; main channel X; concave ring 112; flat band 1121; second connecting rod 11211; normal band 1122; connecting tube 113; aortic arch 401; branch blood vessel 402; branch stent 2; temporary operation space M; proximal end E; distal end F; proximal end closure area A; concave flow guide area B; distal end closure area C; proximal end exposed area D; pre-opening Y; false cavity 4011; true cavity 4012; DETAILED DESCRIPTION

[0049] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0050] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0051] For the convenience of description, the professional terms appearing in the text are explained as follows:

[0052] Proximal end: The arteries that originate from the heart gradually branch into capillaries, and then gradually converge into veins and return to the heart. The end of any blood vessel that is closest to the heart is called the proximal end.

[0053] Distal end: The arteries that originate from the heart gradually branch into capillaries, and then gradually converge into veins and return to the heart. The end of any blood vessel farthest from the heart is called the distal end.

[0054] Axial direction: Blood vessels, interventional stents, etc. are all quasi-circular tubes. If they are regarded as cylinders, the rotation axis of the cylinder is defined as the axial direction. In the description of the present invention, unless otherwise specified, the axial direction of the stent graft refers to the axial direction of the main channel.

[0055] Radial direction: The radial direction is perpendicular to the axial direction, i.e. the radius or diameter direction of the end circle of a cylinder. The radial direction is perpendicular to the axial direction. In the description of the present invention, unless otherwise specified, the radial direction of the stent graft refers to the radial direction of the main channel.

[0056] Circumferential direction: "Circumferential direction" refers to the circumferential direction, which together with "axial direction" and "radial direction" constitute the three orthogonal directions of cylindrical coordinates. In the description of the present invention, unless otherwise specified, the circumferential direction of the stent graft refers to the circumferential direction of the main channel.

[0057] like Figures 1 to 3 , Fig. 9 As shown, in this embodiment, the present invention provides a stent graft, Figure 1 An exemplary structural schematic diagram of the coated stent is shown, the coated stent 1 includes a plurality of closed rings 10, a plurality of guide rings 11 and a coating 12, the coating 12 is attached to the closed rings 10 and the guide rings 11 to enclose a main channel X, and in this embodiment, the guide ring 11 includes a support ring 111 and a recessed ring 112, the recessed ring 112 includes a flat band 1121 and a normal band 1122, the support ring 111 is connected to the recessed ring 112 and is located on the outside of the flat band 1121, the coating 12 is recessed inwardly along a local area of ​​the circumference of the coated stent 1 and is attached to the flat band 1121 of the recessed ring 112 to form a concave coating 121, and a temporary operating space M is formed between the concave coating 121 and the support ring 111 on its outside.

[0058] It should be noted that if Figures 1 to 3 As shown, the coating 12 is attached to the surface of the closed ring 10 and part of the surface of the guide ring 11 by sewing or hot melting, and the coating 12 is a flexible film, which can be made of materials such as PET (Polyethylene terephthalate, polyester fiber, polyester) or EPTFE (expanded, expanded polytetrafluoroethylene).

[0059] It should be noted that if Figures 1 to 3 As shown, the coating 12 is a connecting component of the coated stent 1, and one of its main functions is to connect the independent closed rings 10 and the guide rings 11. At the same time, the coating 12 is made of flexible material, so that the coated stent 1 has strong bending and compliance properties, which can ensure that the coated stent 1 can be transported in curved blood vessels and adapt to the curved structure of interventional blood vessels.

[0060] It should be noted that if Figures 1 to 3 As shown, the coating 12 also has a sealing function, that is, after the coated stent 1 is inserted into the diseased blood vessel stent, the coating 12 covers the diseased area, which can not only seal the rupture but also ensure that blood does not penetrate.

[0061] For ease of explanation, Figures 1 to 3As shown, according to the position of the stent graft 1 intervening in the aortic arch 401, the two ends of the stent graft 1 are defined. In the following description, the end of the stent graft 1 close to the concave coating 121 is defined as the proximal end E, and the other end of the stent graft 1 is defined as the distal end F.

[0062] like Figures 1 to 3 As shown, in this embodiment, a proximal end closed area A, a concave guide area B and a distal end closed area C are sequentially arranged from the proximal end E to the distal end F, and the closed ring 10 is arranged along the proximal end closed area A and the distal end closed area C, and the proximal end closed area A and the distal end closed area C are formed by attaching the coating 12 to the closed ring 10, the concave guide area B is provided with the guide ring 11, and the concave coating 121 is located in the concave guide area C.

[0063] like Figures 1 to 3 As shown, in this embodiment, the proximal closed area A is a tubular area on the coated stent 1 close to the proximal segment E, the closed ring 10 in this area is completely attached by the coating 12 to form a sealed lumen, and the diameters of the axial circular sections of the proximal closed area A are the same.

[0064] It should also be noted that if Figures 1 to 3 As shown, in the present embodiment, a closed ring 10 portion of the proximal end E is attached with a coating 12, and the other exposed portion extends axially toward the proximal end E to form a proximal exposed area D, and the inner and outer surfaces of the proximal exposed area D are not attached with the coating 12. The closed ring 10 of the proximal exposed area D also has the function of being snap-connected with the delivery system and pulling the coated stent 1 to move. At the same time, the closed ring 10 of the proximal exposed area D also has the function of preventing the rupture from tearing back.

[0065] like Figures 1 to 4 As shown, in this embodiment, the concave guide area B is a semi-enclosed area in the middle of the coated stent 1, which is located between the proximal end closed area A and the distal end closed area C. In the concave guide area B, the inner surface or the outer surface or the inner and outer surfaces of the concave ring 112 are attached with a coating 12, and the inner and outer surfaces of the support ring 111 are not attached with the coating 12. The coating 12 forms a concave circumferential shape along the concave ring 112, that is, the concave coating 121 is formed. A pre-opening Y is provided on the concave coating 121 of the coating 12. The pre-opening Y should be provided in the middle of the opening angle of the flat band 1121 of the concave ring 112 to avoid the interference of the wave rod with the pre-opening Y. The pre-opening Y is used for the implantation of the branch stent 2 between the pre-opening Y and the branch vessel 402 after the coated stent 1 intervenes in the aortic arch 401, so as to close the pre-opening Y and reconstruct the branch vessel cavity. Figure 4 A schematic diagram showing the use of a branch stent to seal the pre-opening and reconstruct the branch vessel lumen.

[0066] like Figures 1 to 3As shown, in the present embodiment, the distal end closed area C is a tubular area on the coated stent 1 close to the distal end F, and the closed ring 10 in this area is completely attached by the coating 12 to form a sealed lumen. At the same time, the axial circular sections of the distal end closed area C are of equal diameter or axially reduced in diameter, and the diameter of the distal end closed area C gradually decreases in the direction from one end close to the concave guide area B to the other end, that is, the diameter of the distal end closed area C gradually decreases in the direction from the proximal end E to the distal end F to produce a certain taper.

[0067] like Figures 1 to 3 , Figure 5 As shown, in the present embodiment, the closed ring 10 is a supporting component of the stent graft 1, and its main function is to maintain the overall tubular shape of the stent graft 1 and provide a supporting force in the blood vessel to anchor the stent graft 1. Specifically, the closed ring 10 is circular, undulating in a wavy shape along the circumferential direction, and the number of crests or troughs of the closed ring 10 is at least three. It should be noted that the closed ring 10 is made of a metal wire through processes such as heat treatment and shaping, and the metal wire material is a shape memory alloy, such as nickel-titanium alloy. The cross-sectional shape of the metal wire is, for example, a suitable shape such as a circle or a square. In the present embodiment, a circular cross-sectional design is adopted.

[0068] like Figure 5 and Figure 6 As shown, in this embodiment, the axial length H1 of the closed ring 10 is, for example, set between 10 mm and 40 mm, and the diameter of the closed ring 10 is, for example, set between 20 mm and 50 mm. It should be noted that when the cross-section of the metal wire of the closed ring 10 is circular, the cross-section circular diameter d1 is, for example, set between 0.1 mm and 1 mm; when the cross-section of the metal wire of the closed ring 10 is square, the diameter of the circumscribed circle of the cross-section square is also set between 0.1 mm and 1 mm. For example, the diameter of the metal wire of the closed ring 10 can be 0.1 mm, 0.2 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, etc. In this embodiment, the closed ring 10 is made by cutting metal pipes. In some other embodiments, the closed ring 10 can be made by 3D metal printing.

[0069] like Figures 1 to 3 , Figure 7 As shown, in this embodiment, the guide ring 11 includes a support ring 111 and a concave ring 112, and the guide ring 111 is a double-layer structure in a circumferential region. Specifically, the two ends of the support ring 111 are directly fixedly connected to the two ends of the flat band 1121 of the concave ring 112 by welding, sewing or hot melting, so as to form a double-layer structure with the concave ring 112.

[0070] like Figure 3 , Figures 7 to 9As shown, in this embodiment, the recessed ring 112 includes a flat band 1121 and a normal band 1122, the support ring 111 is connected to the recessed ring 112 and is located on the outside of the flat band 1121 to form a double-layer structure, the coating 12 is recessed inward along a local area of ​​the circumference of the coating support 1 and attached to the flat band 1121 of the recessed ring 112 to form an inner concave coating 121, and a temporary operating space M is formed between the inner concave coating 121 and the support ring 111 on its outside.

[0071] like Figure 3 , Figures 7 to 10 As shown, in this embodiment, in terms of form, the support ring 111 can be regarded as a selected part of the closed ring 10 in the circumferential direction, which is in the shape of an arc, undulating in a wave shape along the circumferential direction, and the number of troughs or peaks of the support ring 111 is at least two. The support ring 111 is made of a metal wire through heat treatment and other processes, and the metal wire material is a shape memory alloy, such as nickel-titanium alloy, and the cross-sectional shape of the metal wire is a suitable shape such as a circle, a square, etc. In this embodiment, a circular cross-sectional design is adopted.

[0072] like Figure 3 , Figures 7 to 10 As shown, in this embodiment, the axial length h of the support ring 111 is, for example, set between 5 mm and 30 mm, and the arc diameter is, for example, set between 20 mm and 50 mm. When the cross-section of the metal wire of the support ring 111 is circular, the cross-section circular diameter d2 is, for example, set between 0.1 mm and 1 mm; when the cross-section of the metal wire of the support ring 111 is square, the diameter of the circumscribed circle of the cross-section square is also set between 0.1 mm and 1 mm. For example, the diameter of the metal wire of the support ring 111 can be 0.1 mm, 0.2 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, etc. In this embodiment, the support ring 111 is made by cutting metal pipes. In some other embodiments, the support ring 111 can be made by 3D metal printing.

[0073] like Figure 3 , Figures 7 to 9 As shown, in this embodiment, in terms of morphology, the concave ring 112 can be regarded as a deformation of the closed ring 10: that is, a plurality of connected waves of the closed ring 10 are merged into one wave, and are concave radially inward to form a flat wave band 1121, and the rest are normal wave bands 1122. For ease of understanding, the annular profile of the concave ring 112 can be understood as a "D"-shaped profile or a "saddle"-shaped profile, and the number of troughs or peaks of the concave ring 112 is at least four.

[0074] like Figure 1As shown, in this embodiment, the concave ring 112 is made of metal wire through heat treatment and other processes. The metal wire material is a shape memory alloy, such as nickel-titanium alloy, and the cross-section of the metal wire is a suitable shape such as a circle or a square. In this embodiment, a circular cross-section design is adopted.

[0075] like Figure 3 , Figures 7 to 10 As shown, in this embodiment, the axial length H1 of the lower concave ring 112 is, for example, set between 10 mm and 40 mm, and the diameter of the lower concave ring 112 is, for example, set between 20 mm and 50 mm.

[0076] It needs to be explained that if Figure 3 , Figures 7 to 10 As shown, in this embodiment, when the cross section of the metal wire of the lower concave ring 112 is circular, the cross section circular diameter d3 is set, for example, between 0.1 mm and 1 mm; when the cross section of the metal wire of the lower concave ring 112 is square, the diameter of the circumscribed circle of the cross section square is also set between 0.1 mm and 1 mm, for example, the metal wire diameter of the lower concave ring 112 can be 0.1 mm, 0.2 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, etc. In this embodiment, the lower concave ring 112 is made by cutting metal pipes. In some other embodiments, the lower concave ring 112 can be made by 3D metal printing.

[0077] like Figure 3 , Figures 7 to 10 As shown, in this embodiment, the two ends of the support ring 111 are fixedly connected to the two ends of the flat band 1121 of the concave ring 112 through a connecting tube 113, so as to form a double-layer structure with the concave ring 112. In this embodiment, the connecting tube 113 is a hollow metal tube, the length L1 of which is set between 1 mm and 10 mm, and the inner diameter of the tube cavity is greater than or equal to the sum of the diameters of the metal wires of the concave ring 112 and the support ring 111.

[0078] like Figure 3 , Figures 7 to 10 As shown, in this embodiment, the material of the connecting tube 113 can be any suitable metal material such as nickel-titanium alloy, stainless steel, etc. The first connecting rods 1110 at both ends of the support ring 111 and the second connecting rods 11211 at both ends of the flat band 1121 of the concave ring 112 are respectively inserted into the connecting tube 113, and the supporting ring 111 and the concave ring 112 are connected and fixed by clamping the connecting tube 113 to form a complete guide ring 11.

[0079] It should be noted that, in some other embodiments, the two ends of the support ring 111 are directly fixedly connected to the two ends of the flat band 1121 of the concave ring 112 by welding, sewing or hot melting, so as to form a double-layer structure with the concave ring. Alternatively, the guide ring 11 can be integrally formed by 3D metal printing.

[0080] like Fig.11 As shown, in another embodiment, the support ring 111 can be regarded as a deformation of the original support ring 111, and two first connecting rods 1110 separated at both ends of the original support ring 111 are connected by a supporting flat band to form a complete ring. Specifically, the support ring 111 is an annular structure, including a supporting flat band 1111 and a supporting normal band 1112, and the flat band 1121 of the concave ring 112 and the supporting flat band 1111 are both connected to the coating 12 to fix the support ring 111 with the concave ring 112, that is, the flat band 1121 of the concave ring 112 and the supporting flat band 1111 are connected by the coating 12. The coating 12 is attached to the supporting flat band 1111 to form a concave coating 121. At this time, the number of crests or troughs of the support ring 111 is at least four. For ease of understanding, the annular profile of the support ring 111 can be understood as a "D"-shaped profile or a "saddle"-shaped profile.

[0081] like Fig.11 As shown, in the above embodiment, the support ring 111 and the recessed ring 112 of the guide ring 11 are two independent components, and the flat band of the support ring 111 is fixed on the concave coating 121 of the recessed guide area B by sewing, hot melting, etc., and the flat band of the recessed ring 112 is embedded in the flat band of the support ring 111, so that the support ring 111 and the recessed ring 112 are fixedly connected to form a complete guide ring 11.

[0082] The coating of the pre-opening area of ​​some existing coated stents is in a concave state, so as to increase the guidewire entry space of the branch stent and the operating space for releasing the branch stent. However, the concave coating has no component support and is free in the lumen of the coated stent. When the heart beats and ejects blood, the free concave coating is displaced by the impact of the blood flow, and the pre-opening on the concave coating also shakes accordingly, causing the pre-opening to be misaligned with the corresponding branch blood vessel in both the axial and circumferential directions. This causes the sheath tube that transports the branch stent to be unable to pass through the corresponding pre-opening hole normally, thereby causing subsequent operations to be obstructed or increasing the difficulty of subsequent operations. Even if the branch stent delivery sheath tube barely passes through the corresponding pre-opening hole, the misalignment will affect the final treatment effect. At the same time, due to the misalignment between the pre-opening hole on the coated stent and the branch blood vessel, the channel of the branch blood vessel is partially blocked by the coating. During the release process of the branch stent, the blood circulation of the blocked branch blood vessel is not smooth.

[0083] like Figure 1 and Figure 3 As shown, in this embodiment, the support ring 111 can support the tubular shape of the concave guide area B, and the flat band 1121 of the concave ring 112 can fix the free "concave coating" while maintaining its concave shape, that is, forming the concave coating 121, preventing the pre-opening Y at the concave coating 121 from being displaced by the impact of blood flow, thereby avoiding the pre-opening from being misaligned with the corresponding branch blood vessels in the axial and circumferential directions, thereby facilitating subsequent operations, and allowing the sheath tube for conveying the branch stent to pass through the corresponding pre-opening Y normally. At the same time, since the support ring 111 can support the tubular shape of the concave guide area B, and the flat band 1121 of the concave ring 112 can fix the free "concave membrane" while maintaining its concave shape to form the inner concave membrane 121, a temporary operating space M is formed between the inner concave membrane 121 and the support ring 111 on its outside, which is equivalent to the inner concave membrane 121 diverting the corresponding area of ​​the aortic arch 401 into an upper flow channel (temporary operating space M) and a lower flow channel (main channel X), and the upper flow channel and the lower flow channel are connected through the pre-opened channel Y, and the branch blood vessels can be connected to the aortic arch 401 through the temporary operating space M (that is, the upper flow channel), which can avoid the occurrence of branch blood vessels being blocked by the membrane.

[0084] The coating of the pre-opening area of ​​some existing covered stents is in a concave state, so as to increase the guide wire entry space and the operating space for releasing the branch stent, and the concave coating is fixed and supported by the concave ring. In order to avoid the pre-opening, the flat wave rod of the concave ring is long, but the long wave rod has poor stability and is still easy to deform after being impacted by high-pressure blood flow. The concave ring is less effective in maintaining the "concave" shape of the coating, that is, it is easy to deform, so that the pre-opening is displaced or the long wave rod blocks the pre-opening, which leads to the obstruction of subsequent operations or increases the difficulty of subsequent operations.

[0085] like Figure 3 and Fig.12 As shown, in this embodiment, the support ring 111 has the function of supporting the closed ring 10, and the short wave rod 1113 connected to the concave ring 112 can effectively enhance the stability of the long wave rod 1123 of the concave ring 112. In another embodiment of the present invention, the flat band 1111 of the support ring 111 is connected to the coating 12, which can directly fix and maintain the concave shape of the coating 12 to form a concave coating 121.

[0086] Fig.13 A schematic diagram of the stent graft for treating aortic arch dissection in this embodiment is shown, wherein: Fig.13 a is a schematic diagram showing aortic arch without dissection. Fig.13 b is a schematic diagram showing aortic arch dissection. Fig.13c represents a schematic diagram of the aortic arch after interventional treatment with a covered stent. The covered stent described in the present invention has the advantage of treating aortic arch dissection. After a dissection occurs in a blood vessel, the false lumen 4011 gradually increases and the true lumen 4012 gradually decreases. Clinical studies have shown that when a dissecting blood vessel receives interventional treatment with a covered stent 1, the blood in the false lumen 4011 is gradually absorbed, the axial cross-section of the false lumen 4011 gradually decreases, and the size of the true lumen 4012 is restored. In this embodiment, when the covered stent 1 is implanted into the dissecting aortic arch 401, the flat band 1121 of the guide ring 11 is squeezed by the false lumen 4011, cannot be completely released, and is radially sunken inward, increasing the exposed space of the concave guide area B, further increasing the access space for the branch stent guide wire, and reducing the difficulty of releasing the branch stent. When the blood in the false lumen 401 is absorbed, the flat band 1121 is also released and expanded, and the size of the true lumen 4012 of the blood vessel reconstructed by the covered stent 1 is restored.

[0087] The present invention proposes a coated stent, wherein a support ring can support the tubular shape of a concave guide area, and a flat band of the concave ring can fix a free "concave coating" while maintaining its concave shape, thereby preventing the concave coating and the pre-opening from being displaced by blood flow impact.

[0088] The present invention proposes a coated stent, wherein the support ring has the function of closed ring support, and the short-wave rod connected to the concave ring can effectively enhance the stability of the long-wave rod, or the flat wave of the support ring is connected to the coating, which can directly fix and maintain the concave shape of the coating.

[0089] The covered stent described in the present invention has the advantage of treating aortic arch dissection. When the covered stent described in the present invention is implanted in the dissected aortic arch, the flat wave of the guide ring is squeezed by the false lumen, cannot be completely released and is recessed radially inward, thereby increasing the exposed space of the concave guide area, further increasing the entry space of the branch stent guide wire, and reducing the difficulty of releasing the branch stent. When the blood in the false lumen is absorbed, the flat wave is also released and expanded, and the true lumen size of the blood vessel reconstructed by the covered stent is restored.

[0090] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope involved in the present application is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the inventive concept, such as a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

[0091] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described here in detail.

Claims

1. A stent graft, It is characterized in that It includes a proximal end closed area, a concave guide area and a distal end closed area which are arranged in sequence, wherein the proximal end closed area and the distal end closed area are provided with a plurality of closed rings, the concave guide area is provided with a plurality of guide rings, the coating is attached to the closed rings and the guide rings, and the guide rings include: A support ring and a concave ring, wherein the concave ring includes a flat band and a normal band, the support ring includes a short-wave rod, the short-wave rod is connected to the concave ring and is located outside the flat band to form a double-layer structure with the concave ring, the coating is concave inwardly along the circumference of the local area of ​​the coating support and attached to the flat band of the concave ring to form a concave coating, and a pre-opening is provided on the concave coating located in the concave guide area, and the pre-opening is located in the middle of the opening angle of the flat band; Among them, the support ring is an annular structure, and also includes a supporting flat band and a supporting normal band. The flat band of the concave ring and the supporting flat band are both connected to the coating to fix the support ring and the concave ring. The coating is attached to the supporting flat band to form the concave coating.

2. The stent graft according to claim 1, It is characterized in that The concave ring is circular and wavy along the circumferential direction, and the number of troughs or peaks of the concave ring is at least four.

3. The stent graft according to claim 1, It is characterized in that The support ring is arc-shaped and wavy along the circumferential direction, and the number of the wave troughs or wave peaks of the support ring is at least two.

4. The stent graft according to claim 3, It is characterized in that The two ends of the support ring are respectively fixedly connected to the two ends of the flat band through a connecting pipe to form a double-layer structure with the concave ring.

5. The stent graft according to claim 4, It is characterized in that The support ring and the concave ring are both made of metal wires, the cross section of the metal wires is circular or square, and the diameter of the circle or the diameter of the circumscribed circle of the square is set between 0.1 mm and 1 mm.

6. The stent graft according to claim 5, It is characterized in that The connecting tube is a hollow metal tube, the length of which is set between 1 mm and 10 mm, and the inner diameter of the tube cavity is greater than or equal to the sum of the diameters of the metal wires of the concave ring and the support ring.

7. The stent graft according to claim 3, It is characterized in that The two ends of the support ring are directly and fixedly connected to the two ends of the flat band by welding, sewing or hot melting, so as to form a double-layer structure with the concave ring.

8. The stent graft according to claim 1, It is characterized in that The closed ring, the support ring and the concave ring are formed by cutting metal pipes or by 3D metal printing.

9. The stent graft according to claim 1, It is characterized in that The axial length of the support ring is set between 5 mm and 30 mm, and the arc diameter of the support ring is set between 20 mm and 50 mm.

10. The stent graft according to claim 1, It is characterized in that The closed ring is circular and wavy along the circumference, and the number of troughs or peaks of the closed ring is at least three.

11. The stent graft according to claim 1, It is characterized in that The axial length of the closed ring is set between 10 mm and 40 mm, and the diameter of the closed ring is set between 20 mm and 50 mm.

12. The stent graft according to claim 1, It is characterized in that The supporting flat band is fixedly connected to the concave covering film by sewing or hot melting.

13. The stent graft according to claim 1, It is characterized in that The diameter of the distal end closed area gradually decreases or remains unchanged along the direction from one end close to the concave guide area to the other end.

14. The stent graft according to claim 1, It is characterized in that The coating is attached to the surface of the closed ring and part of the surface of the guide ring by sewing or hot melting, and the coating is a flexible film.

15. The stent graft according to claim 1, It is characterized in that The coating is attached to the inner surface or the outer surface or the inner and outer surfaces of the concave ring, and the coating is not attached to the inner and outer surfaces of the support ring.

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