WO2022227283A1

WO2022227283A1 - Aortic covered stent

Info

Publication number: WO2022227283A1
Application number: PCT/CN2021/105467
Authority: WO
Inventors: 孟庄源; 王盛章
Original assignee: 光华临港工程应用技术研发(上海)有限公司
Priority date: 2021-04-30
Filing date: 2021-07-09
Publication date: 2022-11-03

Abstract

An aortic covered stent, comprising: a first covered stent unit (1), which comprises a first covering membrane, a first support unit used for supporting the first covering membrane, and a first bare stent (15), wherein a distal end of the first bare stent (15) is fixedly connected to the first covering membrane and/or the first support unit, and a proximal end of the first bare stent (15) is located outside the first covering membrane; and a second covered stent unit (2), which comprises a second covering membrane (21), a second support unit used for supporting the second covering membrane (21), and a second bare stent (25), wherein a distal end of the second bare stent (25) is fixedly connected to the second covering membrane (21) and/or the second support unit, and a proximal end of the second bare stent (25) is located outside the second covering membrane (21). A distal part of the first covered stent unit (1) is located in the interior of the second covered stent unit (2), and the first covered stent unit (1) located in the interior of the second covered stent unit (2) is partially fixedly connected to the second covering membrane (21) and/or the second support unit and/or the second bare stent (25). The aortic covered stent may effectively reduce the risk of endoleak, may be prepared according to blood vessel characteristics, has a simple structure, and is convenient to fabricate.

Description

A kind of aortic covered stent

technical field

The invention belongs to the technical field of medical devices, and in particular relates to an aortic covered stent.

Background technique

The aortic blood flow is fast and the pressure is high, and the blood flow is more likely to cause trauma to the blood vessels or amplify the blood vessel trauma. Aortic dissection is one of the most common cardiovascular and cerebrovascular diseases. Aortic dissection is a dangerous acute condition that can be rapidly fatal even with prompt and aggressive treatment. Aortic dissection is the result of the interaction of abnormal membrane structure and abnormal hemodynamics of the aorta. When the structure of the aortic membrane is abnormal, the aorta is prone to dehiscence. If the aortic dissection is completely torn, it will cause rapid and massive blood loss, leading to blood circulation failure and immediate death.

After thoracic aortic intramural repair, blood may continue to flow into the false lumen. The reason is that the communication between the dissection and the arterial blood flow is not completely isolated after the stent is released for aortic dissection. This phenomenon is called endoleak. The most important type of endoleak in aortic dissection is type I endoleak: blood flows into the false lumen through the gap between the proximal end of the stent and the aorta. The reasons include excessive tortuosity and dilation of the descending aortic arch, inappropriate anchoring zone, and stent diameter. Improper selection will result in inadequate sealing of proximal intimal ruptures. Type I endoleak must be dealt with in time, because after stent placement, the high-speed blood flow at the proximal end of the stent will turn the false lumen into a high-pressure lumen that can only enter and not enter, which greatly increases the probability of false lumen formation, and has a negative impact on the distal end of the stent. In the case of re-perforation, continuous proximal high-speed blood flow will also block the thrombosis of the false lumen and cannot guarantee the efficacy of stent treatment. In addition, the normal aorta has a natural tapering rate. When the aorta has dissection, the tapering rate is further expanded. Most of the stent-grafts currently used in clinics are straight or fixed tapered designs, which do not conform to the physiological characteristics of the normal aorta. When doctors choose stents, they choose stents that meet the requirements of the proximal end of the anastomotic vessel, but it is difficult to meet the requirements of the distal end of the anastomotic vessel. Furthermore, the change of the position of the aortic arch with the cardiac cycle and the change of blood vessel diameter with the change of blood pressure during the cardiac cycle will cause the stent to erode the vessel wall to a certain extent. The erosion of the aortic arch of the bare stent is obviously stronger than that of other parts. However, in patients with dissection, the intima and media are often peeled off and touch the aortic arch, so the ability of dissection vessels to withstand stent erosion is much lower than that of normal vessels.

Therefore, how to solve the damage or damage to the blood vessel caused by both ends of the stent graft, and avoid the local stress concentration at the distal end or proximal end of the stent, which may cause new ruptures, poor contact between the stent graft and the blood vessel wall, and rupture of the stent graft. Leakage is a technical problem to be solved urgently by those skilled in the art.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the shortcomings of the prior art, and to provide an aortic stent graft that can effectively reduce the risk of endoleak, has small elastic return force, and is good for blood vessel support, and can be prepared according to the characteristics of blood vessels.

For achieving the above object, the technical scheme provided by the present invention is:

A first aspect of the present invention provides an aortic stent-graft, which has an expanded state and a contracted state, the inner diameter of the aortic stent-graft in the expanded state is greater than the inner diameter of the aortic stent-graft in the contracted state, and the aortic stent-graft is The stand includes:

A first covered stent unit, the first covered stent unit includes a first covered film, a first support unit for supporting the first covered film, and a first bare stent; the distal end of the first bare stent is fixedly connected with the first covering film and/or the first supporting unit, the proximal end of the first bare stent is located outside the first covering film; the first supporting unit includes A plurality of stent rings arranged axially and spaced apart of the first stent-graft unit, and/or, the first support unit includes a braided tubular structure;

A second covered stent unit, the second covered stent unit includes a second covering, a second supporting unit for supporting the second covering, and a second bare stent, the distal end of the second bare stent is fixedly connected with the second covering film and/or the second supporting unit, the proximal end of the second bare stent is located outside the second covering film; the second supporting unit includes A plurality of stent rings arranged axially and spaced apart of the second stent-graft unit, and/or, the second support unit includes a braided tubular structure;

A portion of the distal end of the first stent-graft unit is located inside the second stent-graft unit, and the first stent-graft unit and the second stent-graft unit located inside the second stent-graft unit The covering film and/or the second supporting unit and/or the second bare stent are connected by partial fixation.

Preferably, the distal end portion of the first stent-graft unit is located inside the second stent-graft unit, and the first stent-graft unit located inside the second stent-graft unit is connected to the second stent-graft unit. The second stent-graft unit is connected by partial fixation. Through the nested structure and the partial fixation of the first and second stent-graft units inside the second stent-graft unit, the setting of the bare stent and the stent ring, on the one hand, it is equivalent to the second stent-graft unit in the second stent-graft unit. A protective layer is added at the place, which can effectively reduce the risk of endoleak caused by the graft rupture, thereby effectively reducing the replacement rate of the aortic stent graft; on the other hand, the elastic return force of the aortic stent graft is reduced. , thereby reducing the local stress concentration at both ends of the aortic stent-graft, thereby reducing the erosion and damage to the vessel wall at both ends of the stent-graft, and significantly reducing the complications of dissection patients at the proximal and distal ends of the stent. On the other hand, the support force of the bracket is good, the release is accurate, and the operation difficulty is reduced.

The bare stent refers to a covered stent without a membrane.

The bare stent plays the role of assisting the fixation of the stent-graft, preventing the displacement of the stent-graft, and at the same time providing convenience for post-release, improving the release accuracy of the stent-graft, and reducing the difficulty of operation.

The "proximal end" of the stent-graft refers to the end of the stent-graft that is close to the heart when it is used in the blood vessel, that is, the proximal end, and the "distal end" refers to the end of the stent-graft that is far away from the heart when the stent-graft is used in the blood vessel. end, that is, the distal end.

The first support unit, the second support unit, and the bare stent may be formed by braiding silk threads, or formed by laser engraving.

The first support unit and the second support unit may be self-expanding stents or stents that are expanded by balloons or the like.

Preferably, the first covering comprises a first part and a second part arranged along the axial direction of the aortic stent-graft, the first supporting unit is only located in the first part, and the second part is located in the the inside of the second stent-graft unit.

Preferably, the first support unit is located inside the first film and all the first support units are fixedly connected to the first film; the second support unit is located in the second film and the second support unit is all fixedly connected with the second membrane; the first membrane located inside the second membrane stent unit is respectively connected with the second support unit and the second membrane. The two bare brackets are fixedly connected by a partial phase. The aortic covered stent of the present invention has less influence on the blood flow in the blood vessel, and reduces the occurrence probability of a series of inflammation and blood vessel damage in the blood vessel. The first membrane inside the second stent-graft unit is partially connected to the second support unit by suturing or other means, thereby reducing the bending state of the stent-graft following the arcuate structure of the aorta after the stent-graft is released and trying to restore its original shape The elastic return force generated by the state.

Further, the local phase fixed connection may be fixedly connected by a plurality of points, or may be fixedly connected by lines or planes arranged at intervals; preferably, the fixed connection is by point.

Preferably, the first support unit includes a first-first support ring and a first-second support ring with different structures, and the numbers of the first-first support ring and the first-second support ring are independently one or two. or more; when the number of the first and second stent rings is two or more, respectively, two or more of the first and second stent rings are arranged along the The first stent-graft unit is arranged at intervals in the axial direction of the first stent-graft unit, and two or more of the first and second stent rings are arranged at intervals along the axial direction of the first stent-graft unit; or, the first A stent ring and the first and second stent rings are arranged at intervals along the axial direction of the first covered stent unit, and there is at least one of the first and second stent rings between adjacent two first and first stent rings;

The second support unit includes the second first support ring, the second second support ring and the second third support ring with different structures, the second first support ring, the second second support ring and the second third support ring. The number of stent rings is independently one, two or more; when the number of the second first stent ring, the second second stent ring and the second third stent ring is two or When there are more than one, two or more of the second-first stent rings are sequentially spaced along the axial direction of the second stent-graft unit, and the two or more second-second stent rings are arranged along the axial direction of the second stent-graft unit. The second stent-graft unit is arranged at intervals in the axial direction of the second stent-graft unit, and two or more of the second three-stent rings are arranged at intervals along the axial direction of the second stent-graft unit; or, the The second first stent ring, the second second stent ring and the second third stent ring are spaced apart along the axial direction of the second stent-graft unit, and there are at least two adjacent second first stent rings between them. One of the second two-stent ring and/or the second three-stent ring.

The stent ring is composed of a cylindrical structure that can be contracted in the radial direction, so that the two parts of the film are expanded to form a cylindrical structure, and each stent ring can undergo radial elastic deformation under the action of external force, changing the radial size of the covered stent It is convenient for the stent-graft to be implanted into the blood vessel minimally through the delivery system after being folded. The stent-graft is released in the true cavity of the thoracic aortic dissection and unfolded to form a new blood flow channel, which can isolate the blood from the rupture.

Further preferably, in the first covered stent unit, the stent ring closest to the first bare stent is the first one stent ring, and the first one stent ring includes the first covered stent. The axis line of the stent unit is the axis and the repeating units a are connected in sequence along the circumferential direction, one repeating unit a is a period, and each repeating unit a includes a first peak a ₁ , one or more second a peak a ₂ , a first valley a ₃ connected with the first peak a ₁ and the second peak a ₂ respectively, and a second valley a ₄ connected with two adjacent second peaks a ₂ , the The distance between the peak of _a peak a1 and the bottom _of the first valley a3 is greater than the distance between the peak of the _second peak a2 and the bottom of the second valley a4 _;

In the second stent-graft unit, the stent ring closest to the second bare stent is the second-first stent ring, and the second-first stent ring includes a shaft of the second stent-graft unit. The central line is the axis and the repeating units a' are connected in sequence along the circumferential direction, one repeating unit a' is a period, and each repeating unit a' includes a first peak a ₁ ', one or more second a peak a ₂ ′, a first valley a ₃ ′ connected with the first peak a ₁ ′ and the second peak a ₂ ′ respectively, and a second valley a connected with two adjacent second peaks a ₂ ′ ₄ ', the distance between the peak of the _first peak a1' and the bottom _of the first valley a3' is greater than the distance between the peak of the second peak a2' and the _second valley _a4 ' the distance between the valley bottoms.

In some embodiments, on the circumferential surface, the valley bottom of the first valley a ₃ of each of the first and second support rings is aligned with the valley bottom of the second valley a ₄ ; on the circumferential surface, each of the The valley bottom of the first valley a ₃ ′ of the second first support ring is aligned with the valley bottom of the second valley a ₄ ′.

After the first stent ring and the second stent ring are unfolded in the circumferential direction, they have a wavy structure with staggered heights and lows, which can effectively reduce local stress concentration and have good radial shrinkage and support. The first one stent ring and the second one stent ring play the role of proximal fixation. By arranging multiple first one stent rings or multiple second one stent rings to be equivalent to the role of the proximal end fixing stent ring, sufficient The radial support force can also have a good release shape, which can effectively reduce the incidence of stent endoleak.

Still further preferably, when there are multiple first-to-support rings, two adjacent first-to-support rings are arranged in mirror images in the axial direction, and are staggered on the circumferential surface, and the staggered distance is a quarter. Between one cycle and three quarters of a cycle;

When there are multiple second-first support rings, two adjacent second-first support rings are arranged in mirror images in the axial direction, and are staggered on the circumferential surface, and the staggered distance is a quarter cycle to four between three cycles.

In some embodiments, the first and second support rings and the first and second support rings are two independently, and the two first and second support rings are arranged in mirror images in the axial direction and staggered on the circumferential surface. The staggered distance is 1/2, and the two second-first support rings are arranged in mirror images in the axial direction and staggered on the circumferential surface, and the staggered distance is 1/2.

Further preferably, each of the first and second stent rings includes a third peak b ₁ and a third valley b ₂ , which are periodically arranged along the circumferential direction with the axis of the first stent-graft unit as the axis. The peak tops of the two adjacent third peaks b ₁ are one cycle; when there are multiple first and second stent rings, the multiple first and second stent rings are along the first stent-graft unit. are arranged in the axial direction and distributed at intervals, and/or, on the circumferential surface, the peaks of the third peaks b ₁ of the two adjacent first and second support rings are aligned, and the valley bottoms of the third valleys b ₂ are aligned. ;

Each of the second and second stent rings includes a third peak b ₁ ' and a third valley b ₂ ', which are periodically arranged along the circumferential direction with the axis of the second stent-graft unit as the axis. The peaks of the two third peaks b ₁ ′ are one cycle; when there are multiple second second stent rings, the multiple second second stent rings are along the length of the second stent-graft unit. Axially arranged and spaced apart, and/or, on the circumferential surface, the peaks of the third peaks b ₁ ′ of two adjacent second and second support rings are aligned, and the valley bottoms of the third valleys b ₂ ′ are opposite to each other together;

Each of the second three stent rings includes fourth peaks c ₁ and fourth valleys c ₂ , which are periodically arranged along the circumferential direction with the axis of the second stent-graft unit as the axis. The peak top of the fourth peak c1 is _a period; when there are multiple second three-stent rings, the multiple second three-stent rings are arranged along the axial direction of the second stent-graft unit And spaced distribution, and/or, the peak tops of the fourth peaks c ₁ of the two adjacent second and third support rings on the circumferential surface are aligned, and the valley bottoms of the fourth valley c ₂ are aligned;

The number of cycles of each of the second two-support rings and each of the second three-support rings is different, and/or the distance between the peaks and valleys of each of the second two-support rings is different from that of each of the second two-support rings. The distance between the peaks and valleys of the second and third bracket rings is different.

After the first and second stent rings and the second and first stent rings are unfolded in the circumferential direction, they have a wave-like structure and have good radial contractility and support, so as to ensure that the covering film adheres to the inner wall of the blood vessel.

After the second and second stent rings and/or the second and third stent rings are deployed in the circumferential direction, they have a wave-like structure, which provides sufficient radial preset support force and ensures the adherence of the distal end membrane.

Wherein, the shape of the wires constituting one cycle of the first and second stent rings, the first and second stent rings, the second and first stent rings, the second and second stent rings, or the second and third stent rings only needs to be a shape with peaks and valleys. , including but not limited to V-shaped, U-shaped, etc.

Further preferably, each of the first stent rings includes 3-6 cycles.

Further preferably, each of the first and second stent rings includes 3-6 cycles.

Further preferably, each of the second-first stent rings includes 3-6 cycles.

Further preferably, each of the second two stent rings includes 3-6 cycles.

Further preferably, each of the second three stent rings includes 6-12 cycles.

By adjusting the number of cycles, the radial shrinkage of each stent ring can be ensured, and a suitable support force in the radial direction can be obtained at the same time, so as to ensure the adherence of the film to the wall.

Further preferably, the distance d1 between the top of the _first peak a1 and the bottom _of the _first valley a3 is the distance d1 between the top of the _second peak a2 and the second valley _a4 The distance d ₂ of the valley bottom is 1.5 to 2.5 times.

Further preferably, the distance d1 between the top of the _first peak a1 and the bottom _of the _first valley a3 is the distance between the top _of the _second peak a2 and the third peak b1. The distance d ₃ between the peak and the bottom of the third valley b ₂ is 0.3 to 0.7 times.

Further preferably, the distance d3 between the peak _of the third peak b1 and the valley bottom of the third valley _b2 is the distance _d3 between the peak _of the fourth peak c1 and the fourth valley _c2 The distance d ₄ between the valley bottoms is 1.2 to 1.5 times.

Further preferably, the distance _d5 between the top of the _first peak a1' and the bottom _of the first valley a3' is the distance between the top of the second peak a2' and the _second peak a2'. The distance d ₆ to the bottom of the valley a ₄ ' is 1.5 to 2.5 times.

Further preferably, the distance d7 between the peak of the third peak b ₁ ′ and the bottom of the third valley b ₂ ′ is the distance d ₇ between the peak of the fourth peak c ₁ and the fourth valley The distance between the valley bottoms of c ₂ is 1.2 to 1.5 times of the distance d ₄ .

Further preferably, the distance d5 between the top of the first peak a ₁ ' and the bottom of the first valley a ₃ ' is the distance d ₅ between the top of the third peak b ₁ ' and the third valley The distance between the valley bottoms of b ₂ ′ is 0.3 to 0.7 times of the distance d ₇ .

Still further preferably, the stent ring located at the most distal end of the second stent-graft unit is the second three stent rings.

Still further preferably, the valley bottoms of the first valley a ₃ and the second valley a ₄ are on the same circumferential surface, and the circumferential surface is perpendicular to the axis of the first stent-graft unit;

The valley bottoms of the first valley a ₃ ′ and the second valley a ₄ ′ are both on the same circumferential surface, and the circumferential surface is perpendicular to the axis line of the second stent-graft unit.

Still further preferably, the first covering located inside the second covered stent unit and the second first stent ring, the second second stent ring, and the second third stent ring pass through a plurality of connection points respectively. Phase fixed connection.

According to some embodiments, the first covering inside the second covering stent unit is fixedly connected with the half waist of the first peak a ₁ ',

And/or, the first covering film located inside the second film-covered stent unit is fixedly connected with the valley bottom of the second valley a ₄ ',

And/or, the first covering film located inside the second covered stent unit is fixedly connected with the peak top of the third peak b ₁ ',

And/or, the first covering film inside the second covering stent unit is fixedly connected with the half waist of the third peak b ₁ ',

And/or, the first membrane located inside the second stent-graft unit is fixedly connected to the half _- waist of the fourth peak c1, and/or, the membrane located inside the second stent-graft unit is The _first covering film is fixedly connected to the peak top of the fourth peak c1.

By connecting the first membrane to the second first stent ring, the second second stent ring, and the second third stent ring at local points, on the premise of ensuring that the first membrane is fully stretched, the stent graft can be further reduced in size After the release, the aorta is in a curved state and wants to restore its original state. The selection of the fixing point is flexible, and can be selected according to the setting of the stent-graft unit, as long as the first membrane can be fully stretched and has a suitable elastic straightening force.

Wherein, the valley bottom of the second valley a ₄ ′ and the half waist of the first peak a ₁ ′ of the second and first stent rings, which play the role of proximal fixation, are sutured with the proximal covering film, so that the proximal edge of the covering film has a More support points will reduce the local stress concentration of the stent graft. Compared with the design of the equal-height proximal fixed stent, this solution effectively reduces the local stress concentration and the number of crests of the proximal fixed stent, so that more and relatively evenly distributed support points can be obtained at the proximal edge of the film. Minimize the pocket effect formed when the stent-graft is compressed in the blood vessel, effectively reducing the risk of endoleak.

Preferably, the proximal end of the first bare stent is bent toward the distal end of the first covered stent unit to form an arc-shaped transition structure;

Preferably, the proximal end of the second bare stent is bent toward the distal end of the second covered stent unit to form an arc-shaped transition structure.

According to a specific and preferred embodiment, the first bare stent includes fifth peaks e ₁ and fifth valleys e periodically arranged along the circumferential direction with the axis of the first stent-graft unit as the axis _2. The peak tops of the two adjacent fifth peaks e ₁ are one cycle, and the valley bottom of the fifth valley e ₂ is bent toward the distal end of the first stent-graft unit to form an arc-shaped transition structure. ;

The second bare stent includes a fifth peak e ₁ ′ and a fifth valley e ₂ ′ which are periodically arranged along the circumferential direction with the axis of the second covered stent unit as the axis, and two adjacent ones are The peak top of the fifth peak e ₁ ′ is a period, and the valley bottom of the fifth valley e ₂ ′ is bent toward the distal end of the second stent-graft unit to form an arc-shaped transition structure.

The end of the bare stent adopts an m-shaped arc transition, which can increase the contact area, reduce local stress, and avoid stress concentration; at the same time, the structural design of inward bending can effectively avoid vascular erosion and vascular perforation caused by barbs at the end of the bare stent. , vascular tear and other events.

Further preferably, a spring coil structure f is set at the peak of the fifth peak e ₁ , and the spring coil structure f is fixedly connected with the inner side of the first coating _; A spring coil structure f' is set at the peak, and the spring coil structure f' is located between the first coating film and the second coating film and is respectively connected with the first coating film and the second coating film Fixed connection.

More preferably, the coil structure f is located in the _first peak a1; the coil structure f' is located in the _first peak a1', which satisfies suitable proximal anchoring and suitable distal anchoring, and increases the coverage. The support point and the effective connection area of the membrane proximal edge of the membrane stent unit improve the adhesion of the membrane proximal end.

According to some specific and preferred embodiments, the second support unit is located inside the second cover film and all the second support units are fixedly connected with the second cover film; the first cover film includes A first part and a second part arranged along the axial direction of the stent-graft, the first support unit is located inside the first part and all the first support units are fixedly connected with the first part and the second part is located inside the second stent-graft unit and is fixedly connected to the second support unit and the second bare stent through a partial fixed connection.

More specifically, the first support unit includes:

A plurality of first-stent rings, the plurality of first-stent rings are located at the proximal end of the first stent-graft unit, and each of the first-stent rings includes The axis line is the axis and the repeating units a are connected in sequence along the circumferential direction, one repeating unit a is a period, and each repeating unit a includes a first peak a ₁ and one or more second peaks a ₂ , a first valley a ₃ connected with the first peak a ₁ and the second peak a ₂ respectively, a second valley a ₄ connected with two adjacent second peaks a ₂ , the first peak a The distance d1 between the peak of ₁ and the bottom _of the _first valley a3 is greater than the distance _d2 between the peak of the _second peak a2 and the bottom of the second valley a4 _; a plurality of The first-one stent rings are arranged along the axial direction of the first covered stent unit and are distributed at intervals, and two adjacent first-one stent rings are arranged in mirror images in the axial direction, and are arranged staggered on the circumferential surface, The staggered distance is between one-quarter cycle and three-quarter cycle;

A plurality of first and second stent rings, the plurality of first and second stent rings are located between the proximal end and the distal end of the first covered stent unit, and each of the first and second stent rings includes the first and second stent rings. The axis line of the stent-graft unit is the axis center and the third peak b ₁ and the third valley b ₂ are arranged in sequence along the circumferential direction, and the peak tops of the two adjacent third peaks b ₁ are one cycle; The first and second stent rings are arranged and spaced apart along the axial direction of the first covered stent unit. On the circumferential surface, the third peak b ₁ of the two adjacent first and second stent rings is The peaks are aligned, and the valley bottoms of the third valley b ₂ are aligned;

The second support unit includes:

A plurality of second-first stent rings, the plurality of second-first stent rings are located at the proximal end of the second stent-graft unit, and each of the second-first stent rings includes a portion of the second stent-graft unit. The axis line is the axis and the repeating units a' are connected in sequence along the circumferential direction, one repeating unit a' is a period, and each repeating unit a' includes a first peak a ₁ ', one or more Two peaks a ₂ ′, a first valley a ₃ ′ connected with the first peak a ₁ ′ and the second peak a ₂ ′ respectively, and a second valley a 2 ′ connected with two adjacent second peaks a ₂ ′ _a4 ', the distance d5 between the peak of the _first peak a1' and the bottom _of the first valley a3' is greater than the distance _d5 between the peak of the _second peak a2' and the second valley The distance d ₆ between the valley bottoms of a ₄ '; a plurality of the second-first stent rings are arranged along the axial direction of the second stent-graft unit and are distributed at intervals, and two adjacent second-first stent rings Mirror setting on the axial direction, staggered setting on the circumferential surface, the staggered distance is between one-quarter cycle and three-quarter cycle;

A plurality of second second stent rings, the plurality of second second stent rings are located between the proximal end and the distal end of the second stent-graft unit, each of the second second stent rings includes The axis line of the stent-graft unit is the axis center and the third peak b ₁ ' and the third valley b ₂ ' are arranged in sequence along the circumferential direction, and the peaks of two adjacent third peaks b ₁ ' are one Period; a plurality of the second and second stent rings are arranged along the axial direction of the second stent-graft unit and are distributed at intervals, and on the circumferential surface, the third peaks of two adjacent second and second stent rings are The peaks of b ₁ ' are aligned, and the valley bottoms of the third valley b ₂ ' are aligned;

A plurality of second three-stent rings, the plurality of second three-stent rings are located at the distal end of the second stent-graft unit, and each of the second three-stent rings includes a portion of the second stent-graft unit. The fourth peak c ₁ and the fourth valley c ₂ are arranged in sequence along the circumferential direction with the axis line as the axis, and the peaks of two adjacent fourth peaks c ₁ are one cycle; a plurality of the second The three-stent rings are arranged along the axial direction of the second stent-graft unit and are distributed at intervals, and the peaks of the fourth peaks c ₁ of the two adjacent second three-stent rings on the circumferential surface are aligned, and the first The valley bottoms of the four valleys c ₂ are relatively aligned.

Still further specifically, the axis lines of the first stent ring and the first stent ring and the axis line of the first stent-graft unit coincide with the axis line of the first stent-graft unit. The axes of the second and second stent rings and the second and third stent rings coincide with the axis of the second stent-graft unit, and each of the first and first stent rings includes 3 to 6 cycles; Each of the first and second stent rings includes 3 to 6 cycles; each of the second first stent rings includes 3 to 6 cycles, and each of the second and second stent rings includes 3 to 6 cycles; each of the second and second stent rings includes 3 to 6 cycles; The second and third stent rings include 6-12 cycles.

More specifically, the valley bottoms of the first valley a ₃ and the second valley a ₄ are on the same circumferential surface, and the circumferential surface is perpendicular to the axis of the first stent-graft unit;

The valley _bottoms of the first valley a3' and the second valley a4' are _on the same circumferential surface, and the circumferential surface is perpendicular to the axis of the second stent-graft unit;

_The distance d1 between the top of the _first peak a1 and the bottom _of the _first valley a3 is the distance between the top of the _second peak a2 and the bottom of the second valley a4 1.5 to 2.5 times of d ₂ ;

The distance d1 between the peak of the _first peak a1 and the bottom _of the _first valley a3 is the distance d1 between the peak of the _second peak a2 and the peak _of the third peak b1. The distance d ₃ between the valley bottoms of the third valley b ₂ is 0.3 to 0.7 times;

The distance d ₃ between the peak of the third peak b ₁ and the bottom of the third valley b ₂ is the distance between the peak of the fourth peak c ₁ (241) and the fourth valley c ₂ 1.2 to 1.5 times the distance d ₄ between the valley bottoms;

_The distance d5 between the peak of the _first peak a1' and the bottom _of the first valley a3' is the distance between the peak of the _second peak a2' and the second valley _a4 ' The distance to the bottom of the valley is 1.5 to 2.5 times of d ₆ ;

The distance d7 between the peak of the third peak b ₁ ′ and the bottom of the third valley b ₂ ′ is the peak of the fourth peak _{c 1} _and the bottom of the fourth valley c ₂ 1.2 to 1.5 times the distance d ₄ ;

The distance d5 between the peak of the first peak a ₁ ' and the bottom of the first valley a ₃ ' is the distance between the peak of the third peak b ₁ ' and the third valley _{b 2} _' The distance between valley bottoms is 0.3 to 0.7 times of d ₇ .

More specifically, the second part is fixedly connected to the half waist of the first peak a ₁ ′; the second part is fixedly connected to the bottom of the second valley a ₄ ′; The second part is fixedly connected with the half waist of the third peak b ₁ '; the second part is fixedly connected with the half waist of the fourth peak c ₁ ; the second part is fixed with the fourth peak c 1 ' The phase is fixedly connected at the peak top _of peak c1.

More specifically, the first bare stent includes a fifth peak e ₁ and a fifth valley e ₂ , which are arranged in sequence along the circumferential direction with the axis of the first covered stent unit as the axis. The peaks of the two fifth peaks e ₁ are one cycle, the proximal end of the first bare stent is located outside the first covering, and the bottom of the fifth valley e ₂ faces the first covering. The distal end of the membrane support unit is bent to form an arc-shaped transition structure, the peak top of the fifth peak e1 is provided with _a spring coil structure f, and the spring coil structure f is fixedly connected to the inner side of the first part;

The second bare stent includes a fifth peak e ₁ ′ and a fifth valley e ₂ ′ which are arranged in sequence along the circumferential direction with the axis of the second covered stent unit as the axis, and the two adjacent ones are The peak top of the fifth peak e ₁ ′ is a period, the proximal end of the second bare stent is located outside the second coating, and the bottom of the fifth valley e ₂ ′ faces the second coating The distal end of the stent unit is bent to form an arc-shaped transition structure, and the peak top of the fifth peak e ₁ ' is set as a spring coil structure f', and the spring coil structure f' is located between the second part and the The second covering films are fixedly connected with the second part and the second covering film respectively.

Preferably, the aortic stent-graft further comprises one or more second stent-graft units I located at the proximal end of the first stent-graft unit, the second stent-graft unit I and the The structure of the first stent-graft unit is the same.

The present invention can formulate different length specifications and the number of nesting layers according to the specific conditions of the patients.

Preferably, the number of the second stent-graft units I is 1-3.

Preferably, when the stent-graft is in a deployed state, the outer diameter of the proximal end of the stent-graft is greater than or equal to the outer diameter of the distal end of the stent-graft.

Since the human blood vessels are in a gradually tapering configuration from the proximal end to the distal end, the degree of gradient is different for different people. According to the percentage that the proximal diameter of the blood vessel is larger than the distal diameter and the stent design requirements, the proximal diameter of the covered stent can be 5% to 50% larger than the distal diameter. In this way, a stent-graft of suitable specifications can be obtained to obtain sufficient supporting force in the blood vessel, so that doctors can choose to meet the requirements of the proximal diameter of the blood vessel and meet the requirements of the distal diameter, so as to avoid the excessive size of the stent at the distal end. The wall bears excessive radial force and causes vascular erosion, and at the same time, it also avoids the need to replace the stent for secondary endoleak.

Preferably, two ends and overlapping parts of the stent-graft are respectively provided with markers.

Preferably, the marking material is one or more of platinum, tantalum, platinum-iridium alloy, gold, and platinum-tungsten alloy.

More preferably, it is a platinum-iridium alloy.

Preferably, the configuration of the indicia may be one or more of a ring, a circle, a wire, a coiled coil, or a tape-off prevention design.

Preferably, the fixing method of the marking can be winding of marking wire, sewing of marking ring, bonding and the like.

During the implantation of the stent-graft in the blood vessel, the doctor will mark the position by marking according to the experience, so that the stent-graft can accurately reach the affected area, and position the stent-graft at the lesion to facilitate observation of its displacement.

Preferably, the materials of the first coating film and the second coating film are biocompatible polymer films.

Further preferably, the material of the first coating film and the second coating film is PET film and/or e-PTFE film;

Preferably, the first support unit and the second support unit are made of stainless steel, memory alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, biodegradable metal, biodegradable polymer, magnesium alloy, pure iron one or more of.

Further preferably, the material of the first support unit and the second support unit is a nickel-titanium alloy.

The fixed connection manner of the first coating film and the second coating film to the first supporting unit and the second supporting unit may adopt methods known in the art, such as sewing, hot melting, bonding, and the like.

The stent-graft of the present invention is used for thoracic aorta and/or pulmonary aorta.

The aortic covered stent of the present invention is used for treating diseases such as arterial dissection, arterial perforation, and aneurysm.

The aortic covered stent of the present invention can obtain sufficient supporting force in the blood vessel, reduce stress concentration, reduce elastic straightening force, prevent multi-level rupture and endoleak, and reduce the impact of the two ends of the covered stent on the blood vessel. Erosion and damage of the wall can significantly reduce the complications at the proximal and distal ends of the stent in patients with dissection, and at the same time effectively reduce the replacement rate of the aortic stent-graft.

Due to the application of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

The aortic covered stent of the present invention can effectively reduce the risk of endoleak, and can be prepared according to the characteristics of blood vessels.

Description of drawings

1 is a schematic diagram of the overall structure of the stent-graft provided in Example 1;

2 is a schematic diagram of the stent structure of the aortic covered stent provided in Example 1;

3 is a schematic diagram of the partial structure of the first one stent ring of Example 1;

4 is a schematic diagram of the partial structure of the first and second stent rings of Example 1;

5 is a schematic diagram of the partial structure of the second-first stent ring of Example 1;

6 is a schematic diagram of the partial structure of the second two stent rings of Example 1;

7 is a schematic diagram of the partial structure of the second three-support ring of Example 1;

8 is a schematic diagram of the partial structure of the first bare stent of Example 1;

9 is a schematic diagram of the partial structure of the second bare stent of Example 1;

10 is a schematic structural diagram of the spring coils of the first bare stent and the second bare stent of Example 1;

11 is a schematic diagram of the distribution of the connection points between the first covering and the second supporting unit of the stent-graft provided in Example 1;

12 is a schematic diagram of the overall structure of the stent-graft provided in Example 2;

In the above drawings, 1, the first stent-graft unit; 11, the first part; 12, the second part; 13, the first stent ring; 131, the first peak a ₁ ; 132, the first second peak a ₂ ; 133, the second second peak a ₂ ; 134, the first valley a ₃ ; 135, the second valley a ₄ ; 14, the first and second support rings; 141, the third peak b ₁ ; 142, the third valley b ₂ ; 15, the first bare stent; 151, the fifth valley e ₂ ; 152, the fifth peak e ₁ ; 153, the m-shaped transition structure of the first bare stent; 154, the coil structure f; 2, the second cover membrane stent unit; 21, the second membrane; 22, the second stent ring; 221, the first peak a ₁ '; 222, the first second peak a ₂ '; 223, the second second peak a ₂ '; 224, the first valley a ₃ '; 225, the second valley a ₄ '; 23, the second two bracket ring; 231, the third peak b ₁ '; 232, the third valley b ₂ '; 24, the first Two or three scaffold rings; 241, fourth peak c ₁ ; 242, fourth valley c ₂ ; 25, second bare scaffold; 251, fifth valley e ₂ '; 252, fifth peak e ₁ '; 253, second The m-shaped transition structure of the bare stent; 254, the coil structure f'; 3, the second stent-graft unit I; 4, the connection point; 5, the marking.

Detailed ways

In the description of the embodiments of the present invention, it should be understood that "proximal end" and "distal end" are relative terms, referring to the part of the stent unit, not limited to the end of the stent graft. At the same time, "proximal" refers to the end of the stent-graft that is close to the heart when it is used in the blood vessel, that is, the proximal end, and "distal" refers to the end of the stent-graft that is far away from the heart when it is used in the blood vessel. , that is, the telecentric end.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as "first" or "second" may expressly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

The following disclosure provides many different implementations or examples for implementing different structures of embodiments of the invention. To simplify the disclosure of embodiments of the present invention, the components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit embodiments of the present invention. Furthermore, embodiments of the present invention may repeat reference numerals and/or reference letters in different instances for the purpose of simplicity and clarity and not in itself indicative of a relationship between the various implementations and/or arrangements discussed.

Example 1

Please refer to Fig. 1-Fig. 11, in order to solve the damage or damage to the blood vessel caused by both ends of the existing aortic stent-graft, the local stress concentration at the distal or proximal end of the stent, resulting in a new break and the contact of the stent-graft with the blood vessel wall For problems such as endoleak caused by defects, membrane rupture, etc., this embodiment provides an aortic stent graft, which includes a first stent-graft unit 1 and a second stent-graft unit 2 .

The first stent-graft unit 1 includes a first membrane and a first support unit for supporting the first membrane, and the second stent-graft unit 2 includes a second membrane 21 and a first membrane for supporting the second membrane 21 . Two supporting units, the distal part of the first stent-graft unit 1 is located inside the second stent-graft unit 2, and the first stent-graft unit 1 and the second stent-graft are located inside the second stent-graft unit 2 The support unit 2 is connected by partial fixation.

As shown in FIG. 1 , the first covering includes a first part 11 and a second part 12 arranged along the axial direction of the aortic stent-graft, and the first part 11 and the second part 12 are integrally formed as a complete covering. The first support unit is only located in the first part 11 , and the second part 12 is located inside the second stent-graft unit 2 . Specifically, the first support unit is located inside the first cover film and all the first support units are fixedly connected to the first cover film; the second support unit is located inside the second cover film and all the second support units are connected to the second cover film. The membrane 21 is fixedly connected; the first membrane located inside the second membrane-covered stent unit 2 (ie, the above-mentioned second part 12 ) is fixedly connected to a part of the second support unit.

Wherein, the fixed connection method between the stent and the covering film may adopt a method known in the art, such as suture, heat fusion, bonding and the like.

Specifically, the first support unit includes one or more first stent rings 13 located at the proximal end of the first stent-graft unit 1 (specifically, the proximal end of the first part 11 ) and one or more first stent rings 13 located at the first stent graft The first and second stent rings 14 between the proximal end and the distal end of the stent unit 1 (specifically, the distal end of the first part 11 ).

More specifically, each of the first and first stent rings 13 includes repeating units a which are arranged in sequence along the circumferential direction with the axis of the first stent-graft unit 1 as the axis, and one repeating unit a is a period, and each repeating unit a Unit a includes a first peak a ₁ 131, one or more second peaks a ₂ , a first valley a ₃ 134 connected to the first peak a ₁ 131 and the second peak a ₂ respectively, and two adjacent peaks a 3 134 . In the second valley a ₄ 135 where the two peaks a ₂ are connected, the distance d 1 between the peak of the first peak a ₁ 131 and the bottom of the first valley a ₃ 134 is greater than the distance d ₁ between the peak of the second peak a ₂ and the second peak a 1 131 Distance d ₂ between valley bottoms of valley a ₄ 135 . Preferably, each of the first stent rings 13 includes 3 to 6 cycles. Preferably, the distance d ₁ between the top of the first peak a ₁ 131 and the bottom of the first valley a ₃ 134 is 1.5 to 1.5 of the distance d ₂ between the top of the second peak a ₂ and the bottom of the second valley a ₄ 135 2.5 times. In this embodiment, as shown in FIG. 2 and FIG. 3 , one repeating unit a includes a first second peak a ₂ 132 and a second second peak a ₂ 133 , and each first and first support ring 13 includes five Period, the distance d 1 between the peak of the first peak a ₁ 131 and the bottom of the first valley a ₃ 134 is ₂ of the distance d ₂ between the peak of the second peak a ₂ and the bottom of the second valley a ₄ 135 times. Of course, in other embodiments, the number of second peaks, the number of cycles, and the specific values of d ₁ and d ₂ in the repeating unit of the first stent ring 13 can be set according to the specific conditions of the blood vessel at the site where the stent-graft is applied. When there are multiple first-one stent rings 13, the first-one stent rings 13 are arranged along the axial direction of the first stent-graft unit 1 and are distributed at intervals, and/or, two adjacent first-one stent rings 13 are located in The shaft is mirrored upwards, and is staggered on the circumferential surface, and the staggered distance is between one-quarter cycle and three-quarter cycle. In this embodiment, as shown in FIG. 2 , two first-one support rings 13 are provided, and the two first-one support rings 13 are arranged in mirror images in the axial direction, and the distance staggered on the circumferential surface is one-half cycle .

More specifically, each of the first and second stent rings 14 includes a third peak b ₁ 141 and a third valley b ₂ 142 which are arranged in sequence along the circumferential direction with the axis of the first stent-graft unit 1 as the axis. The peaks of the two adjacent third peaks b ₁ 141 are one cycle. Preferably, the distance d ₁ between the peak of the first peak a ₁ 131 and the bottom of the valley of the first valley a ₃ 134 is the peak of the second peak a ₂ and the peak of the third peak b ₁ 141 and the third valley b The distance d ₃ between the valley bottoms of ₂ 142 is 0.3 to 0.7 times. In this embodiment, as shown in FIG. 2 , the distance d 1 between the peak of the first peak a ₁ 131 and the bottom of the first valley a ₃ 134 is the distance d ₁ between the peak of the second peak a ₂ and the third peak 0.5 times the distance d ₃ between the peak of b ₁ 141 and the bottom of the third valley b ₂ 142 . Preferably, each of the first and second stent rings 14 includes 3 to 6 cycles. In this embodiment, as shown in FIG. 2 and FIG. 4 , the first and second support rings 14 include 5 cycles. When there are multiple first and second stent rings 14 , the multiple first and second stent rings 14 are disposed along the axial direction of the first stent-graft unit 1 and are distributed at intervals, and/or, two adjacent first and second stent rings The rings 14 are arranged overlapping on the circumferential surface. In this embodiment, as shown in FIG. 2 , two first and second support rings 14 are provided, and on the circumferential surface, the peaks of the third peaks b ₁ to 141 of the two first and second support rings 14 are aligned, and the third valleys The valley bottoms of b ₂ 142 are aligned.

The shapes of the wires constituting one cycle of the first and second stent rings 13 and 14 only need to have peaks and valleys, including but not limited to V-shape, U-shape and the like. In this embodiment, as shown in FIG. 3 , after the first and first stent rings 13 are unfolded in the circumferential direction, they have a wavy structure with staggered heights and lows, which can effectively reduce local stress concentration and have good radial shrinkage and support. The first and first stent rings 13 play the role of proximal fixing. By setting two first and first stent rings 13 to be equivalent to the role of the proximal fixing stent rings, sufficient radial support force can be obtained and a good release form can be obtained. , effectively reducing the incidence of stent endoleak; as shown in FIG. 4 , after the first and second stent rings 14 are expanded in the circumferential direction, they have a sawtooth waveform structure, which has good radial shrinkage and support, and ensures that the covering film fits on the lining of blood vessels.

Specifically, the second support unit includes one or more second stent rings 22 located at the proximal end of the second stent-graft unit 2 and one or more second stent rings 22 located between the proximal end and the distal end of the second stent-graft unit 2 The second and second stent rings 23 in between and one or more second third stent rings 24 located at the distal end of the second stent-graft unit 2 .

More specifically, each second-first stent ring 22 includes repeating units a' that are arranged in sequence along the circumferential direction with the axis of the second stent-graft unit 2 as the axis, and one repeating unit a' is a period, and each repeating unit a' is a period. The repeating units a' include a first peak a ₁ '221, one or more second peaks a ₂ ', a first valley a ₃ ' connected to the first peak a ₁ '221 and the second peak a ₂ ', respectively 224. The second valley a ₄ '225 connected to two adjacent second peaks a ₂ ', the distance d ₅ between the peak of the first peak a ₁ '221 and the bottom of the first valley a ₃ '224 greater than the distance d ₆ between the peak of the second peak a ₂ ′ and the valley bottom of the second valley a ₄ ′ 225 . Preferably, each of the second-first stent rings 22 includes 3 to 6 cycles. Preferably, the distance d5 between the peak of the _first peak _a1'221 and the bottom of the first valley _a3'224 is the distance between the peak of the _second peak a2' and the bottom of the second valley _a4'225 . 1.5 to 2.5 times of d ₆ . In this embodiment, as shown in FIG. 2 and FIG. 5 , one repeating unit a' includes two second peaks a ₂ ', each second-first support ring 22 includes 5 periods, and the first peak a ₁ '221 The distance d5 between the top of the peak and the bottom of the first valley _a3'224 is twice the distance d6 between the top of the _second peak _a2 ' and the bottom of the second valley _a4'225 _. Of course, in other embodiments, the number of second peaks, the number of cycles, and the specific values of d ₅ and d ₆ in the repeating unit of the second-first stent ring 22 can also be set according to the specific conditions of the blood vessel at the site where the stent-graft is applied. When there are multiple second-first stent rings 22, the second-first stent rings 22 are disposed along the axial direction of the second stent-graft unit 2 and are distributed at intervals, and/or, two adjacent second-first stent rings 22 are located in The shaft is mirrored upwards, and is staggered on the circumferential surface, and the staggered distance is between one-quarter cycle and three-quarter cycle. In this embodiment, as shown in FIG. 2 , two second-first support rings 22 are provided, and the two second-first support rings 22 are arranged in mirror images in the axial direction, and the distance staggered on the circumferential surface is one-half cycle .

More specifically, each of the second and second stent rings 23 includes a third peak b ₁ '231 and a third valley b ₂ '232 which are arranged in sequence along the circumferential direction with the axis of the second stent-graft unit 2 as the axis. , the peaks of the two adjacent third peaks b ₁ '231 are one cycle. Preferably, each of the second two stent rings 23 includes 3 to 6 cycles. In this embodiment, as shown in FIG. 2 and FIG. 6 , the second and second support rings 23 include 5 cycles. When there are multiple second and second stent rings 23, the plurality of second and second stent rings 23 are disposed along the axial direction of the second stent-graft unit 2 and are distributed at intervals, and/or two adjacent second and second stent rings 23 are arranged overlapping on the circumferential surface. In this embodiment, as shown in FIG. 2 , two second and second support rings 23 are provided, and on the circumferential surface, the peaks of the third peaks b ₁ ′ 231 of the two adjacent second and second support rings 23 are Relatively aligned, the valley bottoms of the third valley b ₂ '232 are relatively aligned.

Each of the second third stent rings 24 includes a fourth peak c ₁ 241 and a fourth valley c ₂ 242 which are arranged in sequence along the circumferential direction with the axis of the second stent-graft unit 2 as the axis. The peak of the fourth peak c ₁ 241 is one cycle. Preferably, each second three-stent ring 24 includes 6 to 12 cycles. In this embodiment, as shown in FIG. 2 and FIG. 7 , the second three-support ring 24 includes 8 cycles. When there are multiple second three-stent rings 24, the multiple second-three-stent rings 24 are arranged along the axial direction of the second stent-graft unit 2 and are distributed at intervals, and/or, two adjacent second-three stents The rings 24 are arranged to overlap on the circumferential surface. In this embodiment, as shown in FIG. 2 , two second and third support rings 24 are provided, and the peaks of the fourth peaks c ₁ 241 of the two adjacent second and third support rings 24 on the circumferential surface are aligned. The valley bottoms of the four valleys c ₂ 242 are relatively aligned.

The distance d3 between the peak of the third peak b ₁ 141 and the bottom of the third valley b ₂ 142 is preferably the distance between the peak of the fourth peak _{c 1} ₂₄₁ and the bottom of the fourth valley c ₂ 242 1.2 to 1.5 times of d ₄ , about 1.3 times in this embodiment; preferably, the distance d ₇ between the peak of the third peak b ₁ '231 and the valley bottom of the third valley b ₂ '232 is the fourth peak c ₁ The distance d ₄ between the peak of 241 and the bottom of the fourth valley c ₂ 242 is 1.2 to 1.5 times, and about 1.3 times in this embodiment. Preferably, the distance d5 between the peak of the _first peak a ₁ '221 and the valley bottom of the first valley a ₃ '224 is between the peak of the third peak b ₁ '231 and the valley bottom of the third valley b ₂ '232 The distance d ₇ is 0.3 to 0.7 times, and in this embodiment, it is about 0.5 times.

The shape of the wires constituting one cycle of the second-first stent ring 22, the second-second stent-ring 23, or the second-third stent ring 24 only needs to be a shape with peaks and valleys, including but not limited to V-shaped, U-shaped, U-shaped type, etc. In this embodiment, as shown in FIG. 5 , after the second-first support ring 22 is unfolded in the circumferential direction, it has a wavy structure with staggered heights and lows, which can effectively reduce local stress concentration, and has good radial shrinkage and support. The second-first stent ring 22 plays the role of proximal fixation. By arranging two second-first stent rings 22 to be equivalent to the role of the proximal-end fixing stent ring, both sufficient radial support force and a good release shape can be obtained. , effectively reducing the incidence of stent endoleak; as shown in FIG. 6 , after the second and second stent rings 23 are expanded in the circumferential direction, they have a sawtooth waveform structure, which has good radial shrinkage and support, and ensures that the covering film fits on the The inner wall of the blood vessel; as shown in FIG. 7 , after the second and third stent rings 24 and the second and third stent rings 24 are unfolded in the circumferential direction, they are in a waveform structure, providing sufficient radial preset support force to ensure the adherence of the distal end covering to the wall sex.

In this embodiment, as shown in FIG. 3 , the valley bottoms of the first valley a ₃ 134 and the second valley a ₄ 135 are on the same circumferential surface, and the circumferential surface is in line with the axis of the first stent-graft unit 1 Vertical; as shown in FIG. 5 , the valley bottoms of the first valley a ₃ '224 and the second valley a ₄ '225 are on the same circumferential surface, and the circumferential surface is perpendicular to the axis line of the second stent-graft unit 2 .

Specifically, the first covering inside the second covering stent unit 2 is fixedly connected to the second first stent ring 22 , the second second stent ring 23 , and the second third stent ring 24 respectively through a plurality of connection points 4 . Of course, it can also be fixedly connected by lines or planes arranged at intervals; preferably fixedly connected by points. After the stent-graft is released, it can significantly reduce the elastic straightening force generated when the stent-graft is in a curved state and wants to restore its original state. In this embodiment, a sutured connection method is used, of course, other methods can also be used.

In this embodiment, as shown in FIG. 11 , the two second-first stent rings 22 are mirror-symmetrically arranged, and the first peak a ₁ '221 of the second-first stent ring 22 at the leftmost end of the second stent-graft unit 2 The peaks, the peaks of the third peaks b ₁ ' 231 of the second two-stent ring 23 and the peaks of the fourth peaks c ₁ 241 of the second three-stent rings 24 are all facing the right end of the second stent-graft unit 2, The leftmost second-first stent ring 22 away from the second stent-graft unit 2 is mirror-symmetrically arranged with the leftmost second-first stent ring 22, so the second-first stent ring at the leftmost end of the second stent-graft unit 2 is far away The first peak a1 of ₂₂ '221 has a peak top facing the left end of the second stent-graft unit 2. In this embodiment, the connection point 4 between the second part 12 and the second stent-graft unit 2 is located at the _first peak a1. Half waist of '221, valley bottom of second valley a ₄ '225, half waist of third peak b ₁ '231, half waist of fourth peak c ₁ 241 and peak of fourth peak c ₁ 241 place. Of course, in other embodiments, the connection point 4 can be selected at other positions of the second-first stent ring 22 , the second-second stent ring 23 , the second-third stent ring 24 or on the inner side of the second membrane 21 , preferably according to this By way of example, the support force of the film is provided by the relatively uniformly distributed connection points 4, so that it has good wall adhesion and shrinkage performance.

Specifically, as shown in FIG. 2 and FIG. 8 , the first stent-graft unit 1 further includes a first bare stent 15 , and the first bare stent 15 includes an axis with the axis of the first stent-graft unit 1 as the axis and extends along the axis. The fifth peak e ₁ 152 and the fifth valley e ₂ 151 arranged in sequence in the circumferential direction, the peaks of the two adjacent fifth peaks e ₁ 152 are one cycle, and the distal end of the first bare stent 15 is connected to the first membrane and/or the first support unit is fixedly connected, the proximal end of the first bare stent 15 is located outside the first covering, and the valley bottom of the fifth valley e ₂ 151 is formed by bending toward the distal end of the first covered stent unit 1 Arc transition structure. As shown in FIG. 8 , the bottom of the fifth valley e ₂ 151 forms the m-shaped transition structure 153 of the first bare support 15 .

As shown in FIG. 2 and FIG. 9 , the second stent-graft unit 2 further includes a second bare stent 25 , and the second bare stent 25 includes the axis line of the second stent-graft unit 2 as the axis and in sequence along the circumferential direction The fifth peak e ₁ '252 and the fifth valley e ₂ '251 are arranged, the peaks of the two adjacent fifth peaks e ₁ '252 are one cycle, and the distal end of the second bare stent 25 is connected to the second membrane 21 and/or the second support unit are fixedly connected, the proximal end of the second bare stent 25 is located outside the second covered stent 21, and the valley bottom of the fifth valley e ₂ '251 faces the distal end of the second covered stent unit 2 Bending to form an arc-shaped transition structure. As shown in FIG. 9 , the bottom of the fifth valley e ₂ ′ 251 forms the m-shaped transition structure 154 of the second bare stent 25 .

The m-shaped transition structure can increase the contact area between the bare stent and the vessel wall, reduce local stress, and avoid stress concentration; at the same time, the inwardly bent structure design can effectively avoid vascular erosion, vascular perforation, vascular perforation, etc. The occurrence of events such as blood vessel tearing.

In this embodiment, as shown in FIG. 8 , the top of the fifth peak e ₁ 152 is provided with a spring coil structure f154 , and the spring coil structure f154 is fixedly connected to the inner side of the first coating; as shown in FIG. 8 , the peak of the fifth peak e ₁ '252 is provided with a spring coil structure f'254, and the spring coil structure f'254 is located between the first coating film and the second coating film 21 and is respectively connected with the first coating film and the second coating film. The cover film 21 is fixedly connected. The coil structure is shown in Figure 10. Increase the support point and the effective connection area of the proximal edge of the covered stent unit, and improve the adhesion of the proximal end of the covering.

In this embodiment, as shown in FIG. 11 , markers 5 are respectively provided at both ends and the overlapping parts of the stent-graft, and the markers 5 are preferably made of platinum, tantalum, platinum-iridium alloy, gold, and platinum-tungsten alloy. One or more, in this embodiment, it is a platinum-iridium alloy; preferably, the configuration of the indicator 5 can be one or more of a ring, a circle, a wire, a coiled coil or an anti-dropping design, no special limits. Preferably, the fixing method of the marker 5 may be winding of marker wire, sewing of marker ring, bonding and the like.

Mark 5 is developed under X-ray, and can be used to indicate the edge of stent graft unit I and the overlapping position of graft I and stent graft unit II, which is convenient for medical staff to locate the middle of the graft, and can make the stent graft accurate. reach the affected area.

Specifically, the material of the first coating film and the second coating film 21 is a biocompatible polymer film, preferably a PET film and/or an e-PTFE film, which is a PET film in this embodiment.

Specifically, the material of the first support unit and the second support unit is one of stainless steel, memory alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, biodegradable metal, biodegradable polymer, magnesium alloy, and pure iron Or more, in this embodiment, it is a nickel-titanium alloy.

Specifically, when the stent-graft is in the deployed state, the outer diameter of the portion of the first stent-graft unit 1 located outside the second stent-graft unit 2 is equal to or greater than the outer diameter of the second stent-graft unit 2 . In actual use, it can be set according to the specific situation of the patient. In addition, in this embodiment, the diameter of the coating film can also be adjusted, and different length specifications can be made. Doctors can select a stent-graft with appropriate specifications according to the tapering of the diseased blood vessel and the length of the lesion, so that the stent-graft can meet the requirements of suitable proximal anchoring, covering all dissection ruptures and suitable distal ends when treating aortic dissection. End anchoring can effectively reduce the reverse tear of the dissection, ineffective occlusion, and complications at the distal end of the stent, and reduce the difficulty and cost of operation.

The stent-graft of the present embodiment can obtain sufficient supporting force in the blood vessel, reduce stress concentration, reduce elastic straightening force, prevent multi-layered ruptures and endoleaks, and reduce the stress on both ends of the stent-graft. The erosion and damage of the vessel wall can significantly reduce the complications at the proximal and distal ends of the stent in patients with dissection, and at the same time effectively reduce the replacement rate of the aortic stent-graft.

Example 2

This embodiment is basically the same as Embodiment 1, except that a second stent-graft unit I3 is added to the proximal end of the first stent-graft unit 1 , and the second stent-graft unit I3 is connected to the first stent-graft unit 1 structure is the same. As shown in FIG. 12 , the outer diameter d ₈ of the second stent-graft unit I3 > the outer diameter d ₉ of the first stent-graft unit 1 > the outer diameter d ₁₀ of the second stent-graft unit 2 . In other embodiments, different length specifications and the number of nesting layers can be formulated according to the specific conditions of the patients. Preferably, the number of the second stent-graft units I3 is 1 to 3. Preferably, when the stent-graft is in the deployed state, the outer diameter of the proximal end of the stent-graft is greater than or equal to the outer diameter of the distal end of the stent-graft.

The stent-grafts of Example 1 and Example 2 can be prepared by conventional methods in the art, and can also be delivered and released in accordance with conventional methods in the art during use.

The stent-grafts of Example 1 and Example 2 can be used to treat diseases such as arterial dissection, arterial perforation, and aneurysm, and the occurrence sites of the diseases include but are not limited to thoracic aorta and pulmonary aorta. Specifically, different configurations can be selected according to the condition of the blood vessels in the diseased part of the patient.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those who are familiar with the art to understand the content of the present invention and implement them accordingly, and cannot limit the scope of protection of the present invention with this. Equivalent changes or modifications made in the spirit and spirit should all be included within the protection scope of the present invention.

Claims

An aortic stent-graft, which has an expanded state and a contracted state, wherein the inner diameter of the aortic stent-graft in the expanded state is greater than the inner diameter of the aortic stent-graft when it is in the contracted state, characterized in that the aortic stent-graft comprises: :

A first covered stent unit, the first covered stent unit includes a first covered film, a first support unit for supporting the first covered film, and a first bare stent; the distal end of the first bare stent is fixedly connected with the first covering film and/or the first supporting unit, the proximal end of the first bare stent is located outside the first covering film; the first supporting unit includes A plurality of stent rings arranged axially and spaced apart of the first stent-graft unit, and/or, the first support unit includes a braided tubular structure;

A second covered stent unit, the second covered stent unit includes a second covering, a second supporting unit for supporting the second covering, and a second bare stent, the distal end of the second bare stent is fixedly connected with the second covering film and/or the second supporting unit, the proximal end of the second bare stent is located outside the second covering film; the second supporting unit includes A plurality of stent rings arranged axially and spaced apart of the second stent-graft unit, and/or, the second support unit includes a braided tubular structure;

A portion of the distal end of the first stent-graft unit is located inside the second stent-graft unit, and the first stent-graft unit and the second stent-graft unit located inside the second stent-graft unit The covering film and/or the second supporting unit and/or the second bare stent are connected by partial fixation.
The stent-graft according to claim 1, wherein the first covering comprises a first part and a second part arranged along the axial direction of the stent-graft, the first supporting The unit is located only in the first part and the second part is located inside the second stent-graft unit.
The stent graft according to claim 1, wherein the first support unit is located inside the first cover, and all the first support units are fixedly connected to the first cover ; the second support unit is located inside the second membrane and all the second support units are fixedly connected with the second membrane; the first support unit located inside the second membrane stent unit The covering film is respectively fixedly connected to the second supporting unit and the second bare stent through partial phases.
The stent-graft according to claim 1, wherein the first support unit comprises a first-first stent ring and a first-second stent ring with different structures, the first-first stent ring and the first-first stent ring and the second stent ring The number of one or two stent rings is independently one, two or more; when the number of the first and second stent rings is two or more respectively, the two or more of the first and second stent rings are sequentially spaced along the axial direction of the first covered stent unit, and two or more of the first and second stent rings are arranged along the first covered stent The units are arranged at intervals in the axial direction of the unit; or, the first and second stent rings and the first and second stent rings are arranged at intervals along the axial direction of the first covered stent unit, and two adjacent first and second stent rings are arranged at intervals. There is at least one of the first and second bracket rings between;

The second support unit includes the second first support ring, the second second support ring and the second third support ring with different structures, the second first support ring, the second second support ring and the second third support ring. The number of stent rings is independently one, two or more; when the number of the second first stent ring, the second second stent ring and the second third stent ring is two or When there are more than one, two or more of the second-first stent rings are sequentially spaced along the axial direction of the second stent-graft unit, and the two or more second-second stent rings are arranged along the axial direction of the second stent-graft unit. The second stent-graft unit is arranged at intervals in the axial direction of the second stent-graft unit, and two or more of the second three-stent rings are arranged at intervals along the axial direction of the second stent-graft unit; or, the The second first stent ring, the second second stent ring and the second third stent ring are spaced apart along the axial direction of the second stent-graft unit, and there are at least two adjacent second first stent rings between them. One of the second two-stent ring and/or the second three-stent ring.
The stent-graft according to claim 4, wherein, in the first stent-graft unit, the stent ring closest to the first bare stent is the first stent ring, and the stent ring is the first stent ring. The first stent ring comprises repeating units a that are connected in sequence along the circumferential direction with the axis line of the first stent-graft unit as the axis, one repeating unit a is a period, and each repeating unit a It includes a first peak a 1 , one or more second peaks a 2 , a first valley a 3 connected to the first peak a 1 and the second peak a 2 respectively, and two adjacent second peaks a 2 connected to the second valley a 4 , the distance between the peak of the first peak a 1 and the bottom of the first valley a 3 is greater than the distance between the peak of the second peak a 2 and the second peak a 2 . the distance between the valley bottoms of valley a 4 ;

In the second stent-graft unit, the stent ring closest to the second bare stent is the second-first stent ring, and the second-first stent ring includes a shaft of the second stent-graft unit. The central line is the axis and the repeating units a' are connected in sequence along the circumferential direction, one repeating unit a' is a period, and each repeating unit a' includes a first peak a 1 ', one or more second a peak a 2 ′, a first valley a 3 ′ connected with the first peak a 1 ′ and the second peak a 2 ′ respectively, and a second valley a connected with two adjacent second peaks a 2 ′ 4 ', the distance between the peak of the first peak a1' and the bottom of the first valley a3' is greater than the distance between the peak of the second peak a2' and the second valley a4 ' the distance between the valley bottoms.
The aortic stent graft according to claim 5, wherein when there are multiple first-to-one stent rings, two adjacent first-to-one stent rings are arranged in mirror images in the axial direction. The surface is staggered, and the staggered distance is between one-quarter cycle and three-quarter cycle;

When there are multiple second-first support rings, two adjacent second-first support rings are arranged in mirror images in the axial direction, and are staggered on the circumferential surface, and the staggered distance is a quarter cycle to four between three cycles.
The aortic stent-graft according to claim 5, wherein each of the first and second stent rings comprises an axial center of the first stent-graft unit and is periodically arranged in a circumferential direction. The third peak b 1 and the third valley b 2 , the peak tops of two adjacent third peaks b 1 are one cycle; when there are multiple first and second support rings, multiple first and second support rings The two stent rings are arranged and spaced apart along the axial direction of the first stent-graft unit, and/or, on the circumferential surface, the peaks of the third peak b 1 of the two adjacent first and second stent rings The top phase is aligned, and the bottom phase of the third valley b 2 is aligned;

Each of the second and second stent rings includes a third peak b 1 ' and a third valley b 2 ', which are periodically arranged along the circumferential direction with the axis of the second stent-graft unit as the axis. The peaks of the two third peaks b 1 ′ are one cycle; when there are multiple second second stent rings, the multiple second second stent rings are along the length of the second stent-graft unit. Axially arranged and spaced apart, and/or, on the circumferential surface, the peaks of the third peaks b 1 ′ of two adjacent second and second support rings are aligned, and the valley bottoms of the third valleys b 2 ′ are opposite to each other Each of the second and third stent rings includes fourth peaks c 1 and fourth valleys c 2 , which are periodically arranged along the circumferential direction with the axis of the second stent-graft unit as the axis. The peak tops of the two fourth peaks c 1 are one cycle; when there are multiple second three-stent rings, the multiple second three-stent rings are along the axis of the second stent-graft unit are arranged and distributed at intervals, and/or, the peak tops of the fourth peaks c1 of the two adjacent second and third support rings on the circumferential surface are aligned, and the valley bottoms of the fourth valleys c2 are aligned;

The number of cycles of each of the second two-support rings and each of the second three-support rings is different, and/or the distance between the peaks and valleys of each of the second two-support rings is different from that of each of the second two-support rings. The distance between the peaks and valleys of the second and third bracket rings is different.
The aortic stent graft according to claim 7, wherein,

Each of the first stent rings includes 3 to 6 cycles,

and/or, each of the first and second stent rings includes 3 to 6 cycles,

and/or, each of the second-first stent rings includes 3 to 6 cycles,

and/or, each of the second and second stent rings includes 3 to 6 cycles,

And/or, each of the second three stent rings includes 6-12 cycles.
The aortic stent graft according to claim 7, wherein,

The distance d1 between the top of the first peak a1 and the bottom of the first valley a3 is the distance between the top of the second peak a2 and the bottom of the second valley a4 1.5 to 2.5 times of d 2 ,

And/or, the distance d1 between the top of the first peak a1 and the bottom of the first valley a3 is the distance between the top of the second peak a2 and the third peak b1. The distance d 3 between the peak and the bottom of the third valley b 2 is 0.3 to 0.7 times,

And/or, the distance d3 between the peak top of the third peak b1 and the bottom of the third valley b2 is the distance d3 between the peak top of the fourth peak c1 and the fourth valley c2 The distance between the valley bottoms of d 4 is 1.2 to 1.5 times,

And/or, the distance d5 between the peak of the first peak a1' and the bottom of the first valley a3' is the distance between the peak of the second peak a2' and the second peak a2'. The distance to the bottom of the valley a 4 ' is 1.5 to 2.5 times of the distance d 6 ,

And/or, the distance d7 between the peak of the third peak b 1 ′ and the bottom of the third valley b 2 ′ is the distance d 7 between the peak of the fourth peak c 1 and the fourth valley The distance between the valley bottoms of c 2 is 1.2 to 1.5 times of the distance d 4 ,

And/or, the distance d 5 between the peak of the first peak a 1 ′ and the bottom of the first valley a 3 ′ is the distance d 5 between the peak of the third peak b 1 ′ and the third valley The distance between the valley bottoms of b 2 ′ is 0.3 to 0.7 times of the distance d 7 .
The stent-graft according to claim 8 or 9, wherein the stent ring located at the most distal end of the second stent-graft unit is the second third stent ring.
The stent-graft of claim 5, wherein:

The valley bottoms of the first valley a 3 and the second valley a 4 are all on the same circumferential surface, and the circumferential surface is perpendicular to the axis of the first stent-graft unit;

The valley bottoms of the first valley a 3 ′ and the second valley a 4 ′ are both on the same circumferential surface, and the circumferential surface is perpendicular to the axis line of the second stent-graft unit.
The aortic stent-graft according to claim 4, wherein the first covering located inside the second stent-graft unit is connected to the second-first stent ring, the second-second stent ring, and the The second and third support rings are respectively fixedly connected through a plurality of connection points.
The aortic stent graft according to claim 7, wherein,

The first membrane located inside the second membrane stent unit is fixedly connected to the half waist of the first peak a 1 ',

And/or, the first covering film located inside the second film-covered stent unit is fixedly connected with the valley bottom of the second valley a 4 ',

And/or, the first covering film located inside the second covered stent unit is fixedly connected with the peak top of the third peak b 1 ',

And/or, the first covering film inside the second covering stent unit is fixedly connected with the half waist of the third peak b 1 ',

and/or, the first covering inside the second covering stent unit is fixedly connected with the half waist of the fourth peak c1,

And/or, the first membrane located inside the second membrane stent unit is fixedly connected to the peak top of the fourth peak c1.
The aortic stent-graft according to claim 1, wherein the first bare stent comprises a fifth peak which takes the axis of the first stent-graft unit as an axis and is periodically arranged in a circumferential direction e 1 , the fifth valley e 2 , the peaks of the two adjacent fifth peaks e 1 are one cycle, and the bottom of the fifth valley e 2 faces the distal direction of the first stent-graft unit Bending to form an arc transition structure;

The second bare stent includes a fifth peak e 1 ′ and a fifth valley e 2 ′ which are periodically arranged along the circumferential direction with the axis of the second covered stent unit as the axis, and two adjacent ones are The peak top of the fifth peak e 1 ′ is a period, and the valley bottom of the fifth valley e 2 ′ is bent toward the distal end of the second stent-graft unit to form an arc-shaped transition structure.
The aortic stent graft according to claim 14, wherein the peak top of the fifth peak e1 is provided with a coil structure f, and the coil structure f is connected to the inner side of the first coating A spring coil structure f' is set at the peak of the fifth peak e 1 ', and the spring coil structure f' is located between the first coating film and the second coating film and is respectively connected with the The first covering film and the second covering film are fixedly connected.
The stent graft according to claim 1, wherein the second supporting unit is located inside the second coating, and all the second supporting units are fixedly connected to the second coating ; the first covering includes a first part and a second part arranged along the axial direction of the aortic stent-graft, the first support unit is located inside the first part and the first support unit is completely It is fixedly connected with the first part, and the second part is located inside the second covered stent unit and is respectively fixedly connected with the second support unit and the second bare stent through partial fixed connection.
The stent graft according to claim 16, wherein the first support unit comprises:

A plurality of first-stent rings, the plurality of first-stent rings are located at the proximal end of the first stent-graft unit, and each of the first-stent rings includes The axis line is the axis and the repeating units a are connected in sequence along the circumferential direction, one repeating unit a is a period, and each repeating unit a includes a first peak a 1 and one or more second peaks a 2 , a first valley a 3 connected with the first peak a 1 and the second peak a 2 respectively, a second valley a 4 connected with two adjacent second peaks a 2 , the first peak a The distance d1 between the peak of 1 and the bottom of the first valley a3 is greater than the distance d2 between the peak of the second peak a2 and the bottom of the second valley a4 ; a plurality of The first-one stent rings are arranged along the axial direction of the first covered stent unit and are distributed at intervals, and two adjacent first-one stent rings are arranged in mirror images in the axial direction, and are arranged staggered on the circumferential surface, The staggered distance is between one-quarter cycle and three-quarter cycle;

A plurality of first and second stent rings, the plurality of first and second stent rings are located between the proximal end and the distal end of the first covered stent unit, and each of the first and second stent rings includes the first and second stent rings. The axis line of the stent-graft unit is the axis center and the third peak b 1 and the third valley b 2 are arranged in sequence along the circumferential direction, and the peak tops of the two adjacent third peaks b 1 are one cycle; The first and second stent rings are arranged and spaced apart along the axial direction of the first covered stent unit. On the circumferential surface, the third peak b 1 of the two adjacent first and second stent rings is The peaks are aligned, and the valley bottoms of the third valley b 2 are aligned;

The second support unit includes:

A plurality of second-first stent rings, the plurality of second-first stent rings are located at the proximal end of the second stent-graft unit, and each of the second-first stent rings includes a portion of the second stent-graft unit. The axis line is the axis and the repeating units a' are connected in sequence along the circumferential direction, one repeating unit a' is a period, and each repeating unit a' includes a first peak a 1 ', one or more Two peaks a 2 ′, a first valley a 3 ′ connected with the first peak a 1 ′ and the second peak a 2 ′ respectively, and a second valley a 2 ′ connected with two adjacent second peaks a 2 ′ a4 ', the distance d5 between the peak of the first peak a1' and the bottom of the first valley a3' is greater than the distance d5 between the peak of the second peak a2' and the second valley The distance d 6 between the valley bottoms of a 4 '; a plurality of the second-first stent rings are arranged along the axial direction of the second stent-graft unit and are distributed at intervals, and two adjacent second-first stent rings Mirror setting on the axial direction, staggered setting on the circumferential surface, the staggered distance is between one-quarter cycle and three-quarter cycle;

A plurality of second second stent rings, the plurality of second second stent rings are located between the proximal end and the distal end of the second stent-graft unit, each of the second second stent rings includes The axis line of the stent-graft unit is the axis center and the third peak b 1 ' and the third valley b 2 ' are arranged in sequence along the circumferential direction, and the peaks of two adjacent third peaks b 1 ' are one Period; a plurality of the second and second stent rings are arranged along the axial direction of the second stent-graft unit and are distributed at intervals, and on the circumferential surface, the third peaks of two adjacent second and second stent rings are The peaks of b 1 ' are aligned, and the valley bottoms of the third valley b 2 ' are aligned;

A plurality of second three-stent rings, the plurality of second three-stent rings are located at the distal end of the second stent-graft unit, and each of the second three-stent rings includes a portion of the second stent-graft unit. The fourth peak c 1 and the fourth valley c 2 are arranged in sequence along the circumferential direction with the axis line as the axis, and the peaks of two adjacent fourth peaks c 1 are one cycle; a plurality of the second The three-stent rings are arranged along the axial direction of the second stent-graft unit and are distributed at intervals, and the peaks of the fourth peaks c 1 of the two adjacent second three-stent rings on the circumferential surface are aligned, and the first The valley bottoms of the four valleys c 2 are relatively aligned.
The stent-graft of claim 17, wherein:

The axes of the first and second stent rings and the first and second stent rings are coincident with the axes of the first covered stent unit,

The axis lines of the second first stent ring, the second second stent ring, and the second third stent ring coincide with the axis line of the second covered stent unit,

Each of the first and second stent rings includes 3 to 6 periods; each of the first and second stent rings includes 3 to 6 periods; and each of the second and first stent rings includes 3 to 6 periods,

Each of the second two-support rings includes 3-6 cycles; and each of the second three-support rings includes 6-12 cycles.
The stent-graft according to claim 18, wherein the valley bottoms of the first valley a 3 and the second valley a 4 are both on the same circumferential surface, and the circumferential surface is the same as the first valley a3. The axis lines of the stent-graft units are perpendicular to each other;

The valley bottoms of the first valley a3' and the second valley a4' are on the same circumferential surface, and the circumferential surface is perpendicular to the axis of the second stent-graft unit;

The distance d1 between the top of the first peak a1 and the bottom of the first valley a3 is the distance between the top of the second peak a2 and the bottom of the second valley a4 1.5 to 2.5 times of d 2 ;

The distance d1 between the peak of the first peak a1 and the bottom of the first valley a3 is the distance d1 between the peak of the second peak a2 and the peak of the third peak b1. The distance d 3 between the valley bottoms of the third valley b 2 is 0.3 to 0.7 times;

The distance d 3 between the peak of the third peak b 1 and the bottom of the third valley b 2 is the distance between the peak of the fourth peak c 1 (241) and the fourth valley c 2 1.2 to 1.5 times the distance d 4 between the valley bottoms;

The distance d5 between the peak of the first peak a1' and the bottom of the first valley a3' is the distance between the peak of the second peak a2' and the second valley a4 ' The distance to the bottom of the valley is 1.5 to 2.5 times of d 6 ;

The distance d7 between the peak of the third peak b 1 ′ and the bottom of the third valley b 2 ′ is the peak of the fourth peak c 1 and the bottom of the fourth valley c 2 1.2 to 1.5 times the distance d 4 ;

The distance d5 between the peak of the first peak a 1 ' and the bottom of the first valley a 3 ' is the distance between the peak of the third peak b 1 ' and the third valley b 2 ' The distance between valley bottoms is 0.3 to 0.7 times of d 7 .
The stent-graft of claim 19, wherein:

the second part is fixedly connected with the half waist of the first peak a 1 ';

the second part is fixedly connected with the bottom of the second valley a 4 ';

the second part is fixedly connected with the half waist of the third peak b 1 ';

the second part is fixedly connected with the half waist of the fourth peak c1;

The second part is fixedly connected to the peak top of the fourth peak c1.
The aortic stent-graft according to claim 20, wherein the first bare stent comprises fifth peaks that take the axis of the first stent-graft unit as the axis and are sequentially arranged in the circumferential direction e 1 , the fifth valley e 2 , the peaks of two adjacent fifth peaks e 1 are one cycle, the proximal end of the first bare stent is located outside the first coating, the first The valley bottom of the five valleys e 2 is bent toward the distal end of the first stent-graft unit to form an arc-shaped transition structure, and the peak of the fifth peak e 1 is provided with a spring coil structure f, and the spring coil structure f is fixedly connected with the inner side of the first part;

The second bare stent includes a fifth peak e 1 ′ and a fifth valley e 2 ′ which are arranged in sequence along the circumferential direction with the axis of the second covered stent unit as the axis, and the two adjacent ones are The peak top of the fifth peak e 1 ′ is a period, the proximal end of the second bare stent is located outside the second coating, and the bottom of the fifth valley e 2 ′ faces the second coating The distal end of the stent unit is bent to form an arc-shaped transition structure, and the peak top of the fifth peak e 1 ' is set as a spring coil structure f', and the spring coil structure f' is located between the second part and the The second covering films are fixedly connected with the second part and the second covering film respectively.
The stent-graft of claim 1, wherein the stent-graft further comprises one or more second stent-graft units located at the proximal end of the first stent-graft unit I, the second stent-graft unit I has the same structure as the first stent-graft unit.
The stent-graft according to claim 1 or 22, wherein when the stent-graft is in a deployed state, the outer diameter of the proximal end of the stent-graft is greater than or equal to the aorta The outer diameter of the distal end of the stent-graft.
The stent-graft according to claim 1, wherein the two ends and overlapping parts of the stent-graft are respectively provided with markers.
The stent-graft according to claim 24, wherein the material of the marking is one or more of platinum, tantalum, platinum-iridium alloy, gold, and platinum-tungsten alloy.
The aortic stent graft according to claim 1, wherein the material of the first coating and the second coating is a biocompatible polymer film.
The aortic stent graft according to claim 26, wherein the material of the first coating and the second coating is PET film and/or e-PTFE film.
The stent-graft according to claim 1, wherein the first support unit and the second support unit are made of stainless steel, memory alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, bioavailable One or more of degraded metals, biodegradable polymers, magnesium alloys, pure iron.
The stent-graft according to any one of claims 1 to 28 is used for treating one or more diseases of arterial dissection, arterial perforation, and aneurysm.
The use according to claim 29, wherein the disease occurrence site is on the thoracic aorta and/or the pulmonary aorta.