Stent graft

Abstract

The present invention provides a coated stent, comprising a stent body, an outer branch and at least one inner branch; the stent body is a tubular structure with a coating on the surface, on which a radially concave recess is formed; the outer branch is cantilevered outside the stent body, one end of which is connected to the side wall of the recess, and has an inner opening on the side wall of the recess; the inner branch is fitted and fixed to the inner wall of the stent body, one end of each inner branch is connected to the side wall of the recess, and has an outer opening on the side wall of the recess; the outer opening is closer to the distal end than the inner opening. The coated stent of the present invention does not need to be customized, has a wide range of applications, and is simple to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a stent graft. Background Art

[0002] Aortic aneurysm refers to the local or diffuse abnormal expansion of the aortic wall. Aortic aneurysm can compress surrounding organs and cause symptoms, and aneurysm rupture is the main danger. Aortic aneurysm often occurs in the ascending aorta, aortic arch, thoracic descending aorta, thoracic abdominal aorta and abdominal aorta. Aortic aneurysm can be divided into true aortic aneurysm, false aortic aneurysm and dissecting aortic aneurysm according to its structure.

[0003] Aortic aneurysm can cause increased pressure inside the blood vessels, so it will expand progressively. If it develops for a long time, it will eventually rupture. The larger the aneurysm, the greater the possibility of rupture. Embolism is another complication. According to statistics, if no surgical treatment is performed, 90% of patients with thoracic aortic aneurysms will die within 5 years, and 75% of patients with abdominal aortic aneurysms will die within 5 years.

[0004] Dissecting aortic aneurysm is caused by local damage to the aortic intima, high-pressure blood flow rushing into the blood vessel wall, causing the media to tear (the tear in the media is usually at the interface between the inner 1 / 3 and the outer 2 / 3 of the media), splitting the complete aortic wall structure into two, and forming a dissecting cavity in the tear gap between the inner and outer walls of the dissection. In order to distinguish it from the aortic cavity, the dissecting cavity is called the false cavity, and the aortic cavity is called the true cavity.

[0005] Aortic diseases may involve branch arteries. Once branch arteries are involved, it will be difficult to solve the problem through interventional methods. At present, intra-arterial treatment has been carried out at home and abroad, that is, a minimally invasive method is used to insert a graft, namely an arterial stent graft, into the diseased artery with the help of the vascular cavity to treat arterial diseases and improve blood supply, thereby achieving the purpose of treatment. When in use, the arterial stent graft is axially compressed and loaded into a conveyor, which is then delivered to the diseased artery through the smaller femoral artery, iliac artery, and brachial artery and then released. Due to the elastic force of the arterial stent graft, it automatically returns to a straight tube shape and clings to the inner wall of the aorta, isolating the arterial diseased area from the blood flow, thereby achieving the purpose of treatment.

[0006] Limited by the current stent structure, existing products involving the treatment of arterial branches have inevitable problems, resulting in the risk of complications during or after treatment. The specific analysis is as follows:

[0007] 1. Chimney bracket

[0008] The "chimney" technique, also known as the parallel stent technique, refers to inserting a stent into the blocked branch vessel and releasing it in parallel with the main stent in the aorta, so as to achieve the purpose of retaining the arch branch. According to the location of the stent, it can be divided into the subclavian artery "chimney", the carotid artery "chimney" and the brachiocephalic artery "chimney"; according to the number of stents, it can be divided into "single chimney", "double chimney" and "triple chimney". The advantages of the "chimney stent" technology are: the surgical instruments used are all conventional instruments, which are easy to obtain clinically; the technical difficulty is relatively low; in the selection of appropriate cases, the incidence of endoleak is low and the blocking effect is good. Its disadvantages are: there is a "groove" between the small stent and the main aortic stent, which is not a perfect blocking technique and there is a risk of endoleak; on the other hand, the main aortic stent is released in parallel with the small stent, and the main stent may compress the small stent, causing poor blood flow or even blockage of the small stent.

[0009] 2. Window type bracket

[0010] The existing "fenestrated stents" mainly include intraoperative in situ fenestration and customized fenestration. In situ fenestration is to first place the aortic main stent to cover the lesion and pre-fenestrated blood vessels, and then introduce the fenestration device (such as hard-tipped guidewire, laser, radiofrequency, etc.) into the pre-fenestrated branch blood vessels, puncture the aortic stent, and then assist the balloon and stent to open the branch blood vessels. The in situ fenestration operation is complicated and has certain requirements on the doctor's surgical level. In addition, the durability and long-term fatigue resistance of the implanted stent are poor, and it is easy to have internal leakage. The pre-fenestrated stent is individually manufactured by the stent manufacturer. Through the results of preoperative imaging examinations, stents that meet the anatomical morphology of the aortic arch of different patients are manufactured. Therefore, this type of stent has good support, adhesion, and positioning capabilities, but customized stents require a certain period of time and are not suitable for emergency cases. In addition, the production of the stent needs to take into account the curvature of the aortic arch, the relative position of the opening of the large blood vessel branches on the arch, the location of the lesion, the marking of the window, the positioning of the stent and other technical details.

[0011] 3. Integrated branch bracket

[0012] The integrated branch stent can avoid the "groove" caused by the implantation of the chimney stent, and can avoid problems such as internal leakage caused by poor window alignment. It has better adhesion and less chance of internal leakage. However, due to multiple technical problems such as branch stent delivery, introduction, positioning, and release, there is still no mature and applicable stent product on the market.

[0013] Therefore, it is necessary to develop an interventional stent system that is more suitable for aortic arch branch reconstruction. Summary of the invention

[0014] The purpose of the present invention is to provide a coated stent that does not require customization, has a wide range of applications, and is simple to operate.

[0015] In order to solve the above technical problems, the present invention adopts the following technical solutions: a coated stent, comprising a stent body, an outer branch and at least one inner branch; the stent body is a tubular structure with a coating on the surface, and a radially recessed recess is formed on the stent body; the outer branch is cantilevered to the outside of the stent body, one end of which is connected to the side wall of the recess, and has an inner opening on the side wall of the recess; the inner branch is fitted and fixed to the inner wall of the stent body, one end of each inner branch is connected to the side wall of the recess, and has an outer opening on the side wall of the recess; the outer opening is closer to the distal end than the inner opening.

[0016] In some embodiments, the number of the inner branches is two, namely a first inner branch and a second inner branch; the first inner branch has a first outer opening on the side wall of the recess, and the second inner branch has a second outer opening on the side wall of the recess, and the second outer opening is closer to the distal end than the first outer opening.

[0017] In some embodiments, the first inner branch extends proximally from the first outer opening.

[0018] In some embodiments, the second inner branch extends distally from the second outer opening.

[0019] In some embodiments, as extending toward the distal direction, the second inner branch further extends from the second outer opening along the circumference of the stent body.

[0020] In some embodiments, as extending toward the proximal direction, the first inner branch further extends from the first outer opening along the circumference of the stent body.

[0021] In some embodiments, the second inner branch extends from the second outer opening in a proximal direction, and as it extends in the proximal direction, the second inner branch also extends from the second outer opening along the circumference of the stent body; the direction in which the second inner branch extends circumferentially is opposite to the direction in which the first inner branch extends circumferentially.

[0022] In some embodiments, the length of the outer branch is 5 mm to 20 mm.

[0023] In some embodiments, the outer branch has a flexibly deformable flexible section, and the flexible section extends outward from the inner opening.

[0024] In some embodiments, the flexible segment is comprised of a flexible film material.

[0025] In some embodiments, the length of the transition section is 2 mm to 10 mm and does not exceed 1 / 2 of the total length of the outer branch.

[0026] In some embodiments, the outer branch and the inner branch are respectively provided with a developing member, and the developing member is made of a non-transmissive material.

[0027] In some embodiments, the developing member is circumferentially arranged at the inner opening or the outer opening.

[0028] In some embodiments, the developing member is disposed on the outer branch or the inner branch along their respective extending directions.

[0029] In some embodiments, the developing member is fixed by heat pressing or sewing.

[0030] In some embodiments, the stent body includes a proximal tube body, an intermediate tube body and a distal tube body arranged in sequence from the proximal end to the distal end; the diameter of the intermediate tube body is smaller than the diameters of the proximal tube body and the distal tube body, and the intermediate tube body constitutes the recess.

[0031] In some embodiments, both ends of the intermediate tube body are connected to the proximal tube body and the distal tube body through a transition tube body; the transition tube body has a truncated cone-shaped transition support frame for supporting the coating, and the small end of the transition support frame faces the intermediate tube body.

[0032] In some embodiments, the proximal tube body is provided with a rear release component; the rear release component is a radially shrinkable annular structure, fixed on the coating, and protrudes out of the proximal edge of the coating in the proximal direction.

[0033] In some embodiments, the rear release component is provided with barbs protruding in the circumferential direction.

[0034] In some embodiments, a development mark is provided at the end of the covering film, and the development mark is made of a non-transmissive material.

[0035] It can be seen from the above technical solution that the present invention has at least the following advantages and positive effects:

[0036] In the coated stent of the present invention, an external branch and at least one internal branch are integrally formed on the stent body, and these branches can provide corresponding positioning and support functions to the external branch stents, and these branches are located in the recess of the stent body. Based on the radial depression of the recess, a certain gap is formed between the recess and the blood vessel wall, which can provide sufficient operating space for the guide wire and the catheter during intracavitary treatment, and facilitate the external branch stent to be quickly delivered into the branch blood vessel during the operation. At the same time, since the recess is radially depressed, after each branch stent is implanted in the blood vessel, the coated stent will not squeeze the branch blood vessel to cause blockage of the branch blood vessel. Each branch stent is anchored to the coated stent using the external branch and the internal branch, respectively, so the surgical operation is simpler and the surgical process is shortened.

[0037] In particular, among the multiple branches of the stent graft, the most proximal branch is an outer branch that overhangs the outside of the stent body. When the stent graft is delivered to the predetermined position of the aorta, the outer branch can extend into the branch artery, such as the innominate artery, so as to facilitate the determination of whether the stent graft is delivered in place; at the same time, after the release of the outer branch, based on the coordination between the outer branch and the branch artery, and the coordination between the stent body and the aorta, the stent graft as a whole is not easy to shift, which is convenient for the subsequent implantation of the branch stent. The inner branch located at the more distal end of the outer branch is located inside the stent body. The inner branch does not exceed the stent body, but only exposes the outer opening on the side wall of the stent body. With the operation space provided by the recess, the branch stent can have a larger position adjustment space when implanted into the branch artery through the inner branch, and the branch artery can be implanted more conveniently. The inner branch does not need to be accurately opposite to the entrance of the branch artery, so the stent graft has a wider applicability and higher versatility.

[0038] By using the covered stent of the present invention, the aortic stent and the external branch artery stent are respectively independent structures, which are applicable to various normal and deformed blood vessels. According to the specific conditions of the lesions, the aortic stent blood vessels and the branch artery stent blood vessels of appropriate sizes can be selected respectively to form a set of stent blood vessel system that is most suitable for the patient, avoiding customized stents, allowing mass production, and effectively saving time and facilitating operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of the first embodiment of the stent graft of the present invention.

[0040] Figure 2 yes Figure 1 Schematic diagram of another viewing direction.

[0041] Figure 3 yes Figure 2 A partial enlarged view of point A in the middle.

[0042] Figure 4 yes Figure 1 Usage status diagram.

[0043] Figure 5 It is a schematic structural diagram of the second embodiment of the stent graft of the present invention.

[0044] Figure 6 It is a schematic structural diagram of the third embodiment of the stent graft of the present invention.

[0045] Figure 7 It is a schematic structural diagram of the fourth embodiment of the stent graft of the present invention.

[0046] Figure 8It is a schematic structural diagram of the fifth embodiment of the stent graft of the present invention.

[0047] Fig. 9 It is a schematic structural diagram of the sixth embodiment of the stent graft of the present invention.

[0048] Fig.10 It is a schematic structural diagram of the seventh embodiment of the stent graft of the present invention.

[0049] The following are the descriptions of the reference numerals:

[0050] 100 / 100a / 100b / 100c / 100d / 100e / 100f, covered stent; 200, first branch stent; 300, second branch stent; 400, third branch stent; 600, aorta; 601, ascending aorta; 602, aortic arch; 603, descending aorta; 700, innominate artery; 800, left common carotid artery; 900, left subclavian artery;

[0051] 1 / 1a / 1c / 1d / 1e / 1f, stent body; 101, support frame; 102 / 102c, coating; 103, recess; 104, transition support frame; 105, rear release component; 106, development mark; 11, proximal tube body; 12, intermediate tube body; 13, distal tube body; 14, first transition tube body; 15, second transition tube body;

[0052] 2 / 2a / 2c / 2d / 2e / 2f, outer branch; 21 / 21a / 21f, inner opening; 22 / 22e / 22f, film; 221f, flexible section; 23 / 23e / 23f, support ring; 24, developing member;

[0053] 3 / 3a / 3b / 3c / 3d / 3e / 3f, first inner branch; 31 / 31a / 31c / 31d, first outer opening; 32 / 32b, developing member;

[0054] 4 / 4a / 4b / 4c / 4d / 4e / 4f, second inner branch; 41 / 41c / 41d, second outer opening; 42 / 42b, developing part. DETAILED DESCRIPTION

[0055] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially used for illustration purposes rather than for limiting the present invention.

[0056] The present invention provides a covered stent which can be used for interventional treatment of aortic vascular disease. Based on the covered stent, the blood flow channels of the aorta and three main branch arteries of the aortic arch can be reconstructed.

[0057] For ease of description, the term "proximal end" is defined herein as the end close to the heart along the direction of blood flow, and the term "distal end" is defined herein as the end away from the heart. The direction of blood flow in an artery is from the proximal end to the distal end.

[0058] For the first embodiment, please refer to Figures 1 to 4 The structure and usage status shown.

[0059] See first Figure 1 and Figure 2 The stent graft 100 of this embodiment mainly includes a stent body 1 and an outer branch 2 and two inner branches 3 and 4 connected to the stent body 1. The outer branch 2 is located outside the stent body 1, and the two inner branches 3 and 4 are both located inside the stent body 1. The outer branch 2 and the two inner branches 3 and 4 are arranged in sequence from the proximal end to the distal end, and are respectively connected and fixed to the stent body 1. For ease of description, the two inner branches 3 and 4 are divided into a first inner branch 3 closer to the proximal end and a second inner branch 4 closer to the distal end.

[0060] Main references Figure 1 The stent body 1 is a tubular structure with a coating 102 on the surface, and its skeleton is mainly composed of a plurality of annular support frames 101 arranged along the axial direction. The support frame 101 is formed into an annular shape by elastic rigid wire and can be contracted or expanded in the radial direction.

[0061] The support frame 101 can be made of shape memory alloy material, preferably nickel titanium alloy material. The coating 102 can be formed of any suitable coating material, including but not limited to: low porosity woven or knitted polyester, polyester material, expanded polytetrafluoroethylene, polyurethane, silicone, ultra-high molecular weight polyethylene or other suitable materials.

[0062] Each support frame 101 is fixed to the inner surface or outer surface of the coating 102 by suturing or heat pressing. The coating 102 is supported by the multiple support frames 101 so that the stent body 1 can be unfolded and maintained as a tubular structure when in use, thereby constructing a channel for blood to pass through.

[0063] Along the axial direction of the stent body 1 from the proximal end to the distal end, the stent body 1 sequentially comprises a proximal tube body 11 , a first transition tube body 14 , an intermediate tube body 12 , a second transition tube body 15 and a distal tube body 13 .

[0064] The proximal tube body 11, the intermediate tube body 12 and the distal tube body 13 are all tubular structures of substantially equal diameter. The diameter D12 of the intermediate tube body 12 is smaller than the diameter D11 of the proximal tube body 11 and the diameter D13 of the distal tube body 13. Thus, from the perspective of the stent body 1 as a whole, a radially concave recess 103 is formed at the intermediate tube body 12.

[0065] As an example, the diameter D12 of the intermediate tube 12 may be approximately 70% to 80% of the diameter D11 of the proximal tube 11, and approximately 75% to 95% of the diameter D13 of the distal tube 13. It is understood that the diameter D11 of the proximal tube 11 and the diameter D13 of the distal tube 13 may be the same or different.

[0066] The first transition tube body 14 and the second transition tube body 15 are both truncated cone-shaped, that is, both are tubular structures with gradually changing diameters. The proximal end of the first transition tube body 14 is connected to the proximal tube body 11, and the distal end of the first transition tube body 14 is connected to the intermediate tube body 12. Accordingly, the proximal diameter of the first transition tube body 14 is larger than the distal diameter. The proximal end of the second transition tube body 15 is connected to the intermediate tube body 12, and the distal end of the second transition tube body 15 is connected to the distal tube body 13. Accordingly, the proximal diameter of the second transition tube body 15 is smaller than the distal diameter.

[0067] Through the first transition tube body 14 and the second transition tube body 15, a smooth transition connection is formed between the intermediate tube body 12 and the proximal tube body 11 and the distal tube body 13 respectively, avoiding the risk of internal leakage or local thrombosis caused by the formation of a structural dead corner similar to a "groove" due to sudden shape change.

[0068] Each tube section 11 , 12 , 13 , 14 , 15 of the stent body 1 is composed of one or more support frames 101 and a coating 102 supported by the support frames 101 .

[0069] In particular, the support frame 101 at the first transition tube body 14 and the second transition tube body 15 is defined as a transition support frame 104. The transition support frame 104 is truncated cone-shaped to respectively maintain the truncated cone-shaped structural form of the first transition tube body 14 and the second transition tube body 15. The small end of the transition support frame 104 faces the intermediate tube body 12.

[0070] In this embodiment, only one transition support frame 104 is provided on each of the first transition tube body 14 and the second transition tube body 15. It is understandable that the number of transition support frames 104 is not limited, and when multiple transition support frames 104 are required, the multiple transition support frames 104 are all truncated cone-shaped and located on the same truncated cone surface.

[0071] As for the proximal tube body 11, the middle tube body 12 and the distal tube body 13, their respective support frames 101 are correspondingly cylindrical, so as to maintain the equal diameter structure of each section of the tube body 11, 12, 13. A plurality of support frames 101 are arranged at intervals on each section of the tube body 11, 12, 13, so that each section of the tube body 11, 12, 13 has good bending performance.

[0072] Preferably, the proximal tube body 11 is further provided with a rear release component 105 for the rear release of the proximal end of the coated stent 100. The rear release component 105 is a radially contractible annular structure, fixed on the coating 102, and protrudes out of the proximal edge of the coating 102 in the proximal direction. The structure of the rear release component 105 is the same as that of the stent 101, but only a part of the rear release component 105 is in contact with the coating 102.

[0073] Furthermore, the post-release component 105 is preferably provided with barbs (not shown) protruding along the circumferential direction. A plurality of barbs may be provided. After the stent graft 100 is released, the barbs may pierce into a human blood vessel to increase the stability of the stent graft 100 after release.

[0074] A plurality of developing marks 106 are provided near the edge of the proximal end of the coating 102 for better observing the release position of the coated stent 100 during surgery. In this embodiment, the developing mark 106 is in a circular ring or 8-shaped structure and is fixed to the coating 102 by suturing or hot pressing. The developing mark 106 is made of an opaque material, which includes but is not limited to: gold, platinum, palladium, rhodium, tantalum, or alloys or composites of these metals. Taking platinum as an example, its alloy can be, for example, platinum-tungsten, platinum-iridium and the like.

[0075] See also Figures 1 to 3 The outer branch 2 is cantilevered outside the bracket body 1, one end of which is connected to the side wall of the middle tube 12, and has an inner opening 21 on the side wall of the middle tube 12. The outer branch 2 extends from the inner opening 21 in a direction away from the middle tube 12.

[0076] The outer branch 2 can be a tubular structure of equal diameter or non-equal diameter. In the present embodiment, the outer branch 2 comprises a tubular film 22 and a plurality of support rings 23 fixed to the surface of the film 22, and the plurality of support rings 23 are arranged at intervals along the axial direction of the outer branch 2. Each support ring 23 has the same structural form as the support frame 101 of the stent body 1, and is also an annular structure that can be radially contracted or expanded. The film 22 can be formed of any suitable coating material, including but not limited to: low porosity woven or knitted polyester, polyester material, expanded polytetrafluoroethylene, polyurethane, silicone, ultra-high molecular weight polyethylene or other suitable materials.

[0077] In other structures not shown, the outer branch 2 may also be in the form of a bare stent, such as a grid-like bare stent.

[0078] The inner opening 21 of the outer branch 2 is sutured and fixed to the coating 102 of the intermediate tube body 12, and is connected to the intermediate tube body 12 as a whole, and the inner cavity of the outer branch 2 is connected to the inner cavity of the intermediate tube body 12. In actual production, a through hole is opened in the coating 102 of the intermediate tube body 12, and the outer branch 2 is sutured to the through hole accordingly.

[0079] The length L2 of the outer branch 2 is preferably 5 mm to 20 mm. When the stent graft 100 is released to the treatment position, the outer branch 2 can be released into the innominate artery. Since the innominate artery is located at the leftmost end (i.e., the most proximal end) of the aortic arch, the cooperation between the outer branch 2 and the innominate artery can better stabilize the position of the stent graft 100, making the stent graft 100 as a whole less likely to shift.

[0080] The outer branch 2 is preferably also provided with a developing member 24. Figure 3 As shown, the developing member 24 is in the shape of dots, and a plurality of developing members 24 are arranged at intervals along the extension direction of the outer branch 2. In addition, a plurality of developing members 24 can also be arranged along the outer periphery of the inner opening 21. The developing member 24 is made of an opaque material and fixed on the film 22 by suturing or hot pressing. Through these developing members 24, it is convenient to observe the position of the outer branch 2 during surgery, so as to facilitate the external branch stent to be introduced into the innominate artery through the outer branch 2 more quickly.

[0081] Still reading Figures 1 to 3 The first inner branch 3 is located as a whole inside the stent body 1 and is fixed to the inner wall of the intermediate tube 12. One end of the first inner branch 3 is connected to the side wall of the intermediate tube 12 and has a first outer opening 31 on the side wall of the intermediate tube 12. The first outer opening 31 is closer to the distal end than the inner opening 21 of the outer branch 2.

[0082] The first inner branch 3 is similar to the outer branch 2, and is a tubular structure of equal or unequal diameter, and can be a bare stent or a stent with a film, which will not be described in detail here. Similarly, a through hole is opened on the coating 102 of the intermediate tube body 12 corresponding to the first inner branch 3, and the first outer opening 31 of the first inner branch 3 can be sutured and fixed on the coating 102.

[0083] Except for the first outer opening 31 , other parts of the first inner branch 3 are located inside the middle tube body 12 and can be fixed to the inner wall of the middle tube body 12 by sewing or bonding.

[0084] Preferably, the first inner branch 3 extends from the first outer opening 31 along the wall of the intermediate tube 12 toward the proximal end. Figure 1 As shown, the extension direction of the first inner branch 3 is substantially consistent with the axis L of the stent body 1 , and the axis of the first inner branch 3 and the axis L of the stent body 1 are in the same plane.

[0085] The first inner branch 3 is also provided with a plurality of developing members 32 along its extension direction. In addition, a plurality of developing members 32 may also be provided around the outer periphery of the first outer opening 31. The relevant features of the developing member 32 are similar to those of the developing member 24 on the outer branch 2, and will not be described again here.

[0086] Still reading Figures 1 to 3The second inner branch 4 is closer to the distal end than the first inner branch 3, and the second inner branch 4 is also located in the middle tube body 12 as a whole, and is fitted and fixed to the inner wall of the middle tube body 12. The second inner branch 4 has a second outer opening 41 on the side wall of the middle tube body 12, and the second outer opening 41 is closer to the distal end than the first outer opening 31.

[0087] The second inner branch 4 extends from the second outer opening 41 toward the distal end along the wall of the intermediate tube 12. The extension direction of the second inner branch 4 is opposite to that of the first inner branch 3, which can prevent the blood flow entrance from being blocked by the first inner branch 3 and unable to enter the blood flow.

[0088] The second inner branch 4 is similarly provided with a plurality of developing members 42 along its extension direction. In addition, a plurality of developing members 42 may also be provided around the outer periphery of the second outer opening 41. Other features of the second inner branch 4 may refer to the first inner branch 3 and will not be described again.

[0089] by Figure 1 From the perspective of FIG. 1 , the inner opening 21 , the first outer opening 31 and the second outer opening 41 are substantially on the same straight line parallel to the axis L of the bracket body 1 , and the three are arranged at intervals. It can be understood that the three may also be spaced apart in the circumferential direction.

[0090] Based on the above introduction to the structure of the stent graft 100, Figure 4 The stent graft 100 is implanted into the aorta 600 through a conveyor to reconstruct the blood flow channel of the aorta 600 when in use. The proximal tube body 11 of the stent body 1 extends into the ascending aorta 601 side of the aorta 600 and fits the vascular wall of the ascending aorta 601, the distal tube body 13 is located at the descending aorta 603 side of the aorta 600 and fits the vascular wall of the descending aorta 603, and the intermediate tube body 12 is located at the aortic arch 602 of the aorta 600. The external branch 2 extends into the innominate artery 700 to stabilize the position of the stent graft 100 in the aorta 600, so that the stent graft 100 as a whole is not easily displaced.

[0091] For the three branch blood vessels of the aorta 600 arch, suitable external branch stents can be selected respectively, and then introduced into the corresponding branch blood vessels respectively through the covered stent 100.

[0092] Specifically, the first branch stent 200 extends from the outer branch 2, enters the innominate artery 700, and reconstructs the blood flow channel between the aorta 600 and the innominate artery 700. The second branch stent 300 extends from the first inner branch 3 through the first outer opening 31, and then enters the left common carotid artery 800, and reconstructs the blood flow channel between the aorta 600 and the left common carotid artery 800. The third branch stent 400 extends from the second inner branch 4 through the second outer opening 41, and then enters the left subclavian artery 900, and reconstructs the blood flow channel between the aorta 600 and the left subclavian artery 900.

[0093] The implantation process is as follows:

[0094] 1. First release the proximal tube body 11 of the stent graft 100;

[0095] 2. Continue to release the proximal part of the middle tube 12, and bury the pre-set guide wire in the outer branch 2. When the pre-set guide wire in the outer branch 2 is released, use a catcher or other instruments to send the guide wire into the innominate artery 700, and send the outer branch 2 into the innominate artery 700;

[0096] 3. Quickly release the other parts of the stent body 1 and complete the post-release of the post-release component 105 of the proximal tube body 11, so that the stent graft 100 is anchored in the aorta 600;

[0097] 4. Through the guidewire and catheter exchange technology, the three branch blood vessels, namely the innominate artery 700, the left common carotid artery 800, and the left subclavian artery 900, are reconstructed in sequence, and branch stents 200, 300, and 400 of corresponding specifications are released respectively. Specifically, the first branch stent 200 is released in the external branch 2 to reconstruct the innominate artery 700, the second branch stent 300 is released in the first internal branch 3 to reconstruct the left common carotid artery 800, and the third branch stent 400 is released in the second internal branch 4 to reconstruct the left subclavian artery 900.

[0098] According to the above introduction, in the stent graft 100 of this embodiment, an outer branch 2, a first inner branch 3 and a second inner branch 4 are integrally formed on the stent body 1, and these branches 2, 3, 4 can respectively provide positioning and support functions for the three branch stents 200, 300, 400 connected to the outside, and these branches 2, 3, 4 are located at the middle tube body 12 of the stent body 1 with a smaller diameter. Since a recess 103 is formed at the middle tube body 12, a certain gap is formed between the recess 103 and the vascular wall of the aortic arch 602, which can provide sufficient operating space for the guide wire and the catheter during intracavitary treatment, so as to facilitate the rapid delivery of the three external branch stents 200, 300, 400 into the branch artery during the operation to reconstruct the three main branch artery blood flow channels of the aortic arch 600. At the same time, since the diameter of the middle tube body 12 is small, after each branch stent 200, 300, 400 is implanted in the blood vessel, the stent graft 100 will not squeeze the branch blood vessel to cause blockage of the branch blood vessel. Each branch stent 200, 300, 400 is anchored to the stent graft 100 using the outer branch 2, the first inner branch 3 and the second inner branch 4 respectively, which simplifies the surgical operation and shortens the surgical process.

[0099] In particular, among the multiple branches 2, 3, and 4 of the coated stent 100, the most proximal branch is the external branch 2 that cantilevers out from the outside of the stent body 1. When the coated stent 100 is delivered to a predetermined position in the aorta 600, the external branch 2 can extend into the innominate artery 700, thereby facilitating determination of whether the coated stent 100 is delivered in place. At the same time, after the external branch 2 is released, based on the coordination between the external branch 2 and the innominate artery 700, and the coordination between the stent body 1 and the aorta 600, the coated stent 100 as a whole is not easily displaced, facilitating the subsequent implantation of branch stents. The two inner branches 3 and 4 located farther away from the outer branch 2 are both located inside the stent body 1. The two inner branches 3 and 4 do not extend beyond the stent body 1, but only expose the outer openings 31 and 41 on the side wall of the stent body 1. Combined with the operating space provided by the recess 103, the branch stent can have a larger position adjustment space when implanted into the branch artery through the inner branches 3 and 4, and can be more conveniently implanted into the branch artery. The inner branches 3 and 4 do not need to be accurately opposite to the entrance of the branch artery, so the coated stent 100 has a wider applicability and higher versatility.

[0100] In addition, in this embodiment, the first inner branch 3 relatively close to the outer branch 2 is an antegrade inner branch, and the blood flow direction therein is consistent with the blood flow direction of the aorta 600, so thrombus formation is not easy.

[0101] Furthermore, the extension direction of the second inner branch 4 is opposite to that of the first inner branch 3, which can prevent the blood flow entrance from being blocked by the first inner branch 3 and unable to enter the blood flow. In particular, since the second inner branch 4 is close to the descending aorta 603 when in use, the extension direction of the second inner branch 4 is consistent with that of the descending aorta 603, and the extension of the second inner branch 4 to the distal end will not affect the blood flow into it.

[0102] For the second embodiment, please refer to Figure 5 The structure shown.

[0103] The main difference between the stent graft 100a of this embodiment and that of the first embodiment is that the extension direction of the first inner branch 3a is different.

[0104] like Figure 5 As shown, in this embodiment, the first inner branch 3a still extends proximally from the first outer opening 31a, but as it extends proximally, the first inner branch 3a also extends from the first outer opening 31a along the circumference of the stent body 1a.

[0105] The extension shape of the first inner branch 3a inside the stent body 1a can be roughly considered as a short spiral line. An angle α is formed between the plane where the axis of the first inner branch 3a is located and the axis L of the stent body 1a, and the angle α is greater than 0 degrees and less than 90 degrees.

[0106] According to the extension mode of the first inner branch 3a, when the extension length of the first inner branch 3a is long, it will not block the inner opening 21a of the outer branch 2a, so that the aortic blood flow can smoothly enter the outer branch 2a through the inner opening 21a and then enter the innominate artery. On the other hand, when a branch stent is connected to the outer branch 2a, the branch stent will extend a certain length toward the inner wall of the stent body 1a as an anchoring area. By setting the first inner branch 3a to extend obliquely relative to the axis L of the stent body 1a, mutual interference between the branch stent connected to the outer branch 2a and the first inner branch 3a can be avoided.

[0107] In the stent graft 100a of this embodiment, the arrangement and structure of the stent body 1a, the outer branch 2a and the second inner branch 4a are the same as those of the first embodiment and will not be described again.

[0108] For the third embodiment, please refer to Figure 6 The structure shown.

[0109] The difference between the stent graft 100b of this embodiment and the second embodiment is that the developing member 32b of the first inner branch 3b and the developing member 42b of the second inner branch 4b are both extended in a linear shape.

[0110] like Figure 6The developing member 32b extends along the axial direction of the first inner branch 3b, and can be a continuous developing wire, or can be continuously wound around the metal frame of the first inner branch 3b in a linear shape. The developing member 42b also extends along the axial direction of the second inner branch 4b.

[0111] Compared with the point-shaped developing members 32 and 42 in the first embodiment, the linear developing members 32b and 42b of this embodiment are continuous in shape. When multiple dispersed developing members are provided, the positions of the first inner branch 3b and the second inner branch 4b can be observed more quickly.

[0112] For the fourth embodiment, please refer to Figure 7 The structure shown.

[0113] The difference between the stent graft 100c of this embodiment and that of the second embodiment is that the extension direction of the second inner branch 4c is different.

[0114] like Figure 7 As shown, the second inner branch 4c still extends from the second outer opening 41c toward the distal end, but as it extends toward the distal end, the second inner branch 4c also extends from the second outer opening 41c along the circumference of the stent body 1c.

[0115] The extension shape of the second inner branch 4c inside the stent body 1c can also be roughly considered as a short spiral line shape. An angle β is formed between the plane where the axis of the second inner branch 4c is located and the axis L of the stent body 1c, and the angle β is greater than 0 degrees and less than 90 degrees.

[0116] According to the extension method of the second inner branch 4c, when the coated stent 100c is implanted into the aorta, the second inner branch 4c can be located in the bending area of ​​the aortic arch. The second inner branch 4c is inclined relative to the axis L of the stent body 1c, so as to avoid the area where the coating 102c is stacked due to bending, thereby preventing the coating 102c from blocking the entrance.

[0117] Figure 7 In the structure shown, the direction in which the second inner branch 4c extends along the circumferential direction is the same as the direction in which the first inner branch 3c extends along the circumferential direction, that is, the second inner branch 4c and the first inner branch 3c are located on the same side of the line connecting the second outer opening 41c and the first outer opening 31c. In other structures not shown, the second inner branch 4c may also extend in the opposite direction to the first inner branch 3c along the circumferential direction.

[0118] In the stent graft 100c of this embodiment, the arrangement and structure of the stent body 1c, the outer branch 2c and the first inner branch 3c are the same as those of the second embodiment and will not be described again.

[0119] For the fifth embodiment, please refer to Figure 8 The structure shown.

[0120] The difference between the stent graft 100d of this embodiment and that of the second embodiment is that the extension direction of the second inner branch 4d is different.

[0121] like Figure 8 As shown, in this embodiment, the second inner branch 4d extends from the second outer opening 41d toward the proximal direction, and as it extends toward the proximal direction, the second inner branch 4d also extends from the second outer opening 41d along the circumference of the stent body 1a.

[0122] The extension shape of the second inner branch 4d inside the stent body 1d can also be roughly considered as a short spiral line. An angle θ is formed between the plane where the axis of the second inner branch 4d is located and the axis L of the stent body 1d, and the angle θ is greater than 0 degrees and less than 90 degrees.

[0123] The second inner branch 4d extends in a circumferential direction opposite to the first inner branch 3d. The two are arranged on both sides of the line connecting the first outer opening 31d and the second outer opening 41d. Figure 8 Taking the viewing direction of as a reference, the first inner branch 3d extends to the left, and the second inner branch 4d extends to the right.

[0124] In this embodiment, the second inner branch 4d is also an antegrade branch, which is consistent with the direction of blood flow. The second inner branch 4d and the first inner branch 3d are both extended obliquely, and the oblique directions are opposite, which can prevent mutual interference.

[0125] For the sixth embodiment, please refer to Fig. 9 The structure shown.

[0126] The difference between the stent graft 100e of this embodiment and the first embodiment is that the length of the outer branch 2e is shorter, which is about 1 / 3 to 1 / 2 of the length of the outer branch 2 in the first embodiment. Only one support ring 23e is provided on the film 22e of the outer branch 2e.

[0127] This embodiment provides a shorter external branch 2e, which has increased flexibility during implantation and can adapt to patients with different anatomical structures. At this time, the shorter external branch 2e can be used as a fixed end of the external branch stent, and there is no strict limitation on the position of the innominate artery.

[0128] In the stent graft 100e of this embodiment, the arrangement and structure of the stent body 1e, the first inner branch 3e and the second inner branch 4e are the same as those of the first embodiment and will not be described again.

[0129] For the seventh embodiment, please refer to Fig.10 The structure shown.

[0130] The difference between the stent graft 100f of this embodiment and that of the first embodiment lies in that the structure of the outer branch 2f is different.

[0131] like Fig.10 As shown, in this embodiment, the outer branch 2f has a flexible segment 221f that can be flexibly deformed, and the flexible segment 221f extends outward from the inner opening 21f. The flexible segment 221 is made of a flexible film material, and no supporting structure is provided thereon, so that it can have greater flexibility and can adapt to patients with more anatomical structures. The length of the flexible segment 221 is approximately 2mm to 10mm, and does not exceed 1 / 2 of the total length of the outer branch 2f.

[0132] The flexible section 221f can be formed by not providing the support ring 23f in a length range of the film 22f close to the stent body 1f. That is, the support ring 23f is not provided in the range of about 2mm to 10mm from the inner opening 21f on the film 22f of the outer branch 2f, and the section of the film 22f without the support ring 23f constitutes the flexible section 221f. The support ring 23f is provided on the part of the film 22f other than the flexible section 221f to keep the outer branch 2f in a tubular shape.

[0133] In the stent graft 100f of this embodiment, the arrangement and structure of the stent body 1f, the first inner branch 3f and the second inner branch 4f are the same as those of the first embodiment and will not be described again.

[0134] In the above-mentioned embodiments, the structure of two inner branches is introduced on the stent body, and the three branch arteries of the aorta can be reconstructed in combination with the outer branches. However, it can be understood that in some embodiments not shown, the number of inner branches can be reduced to one, which is suitable for the situation where two branch arteries need to be reconstructed.

[0135] From the detailed introduction of the above-mentioned embodiments, it can be known that the coated stent of the present invention can make the aortic stent and the external branch artery stent into independent structures, which are applicable to various normal and deformed blood vessels. According to the specific conditions of the lesions, the aortic stent blood vessels and the branch artery stent blood vessels of appropriate sizes can be selected respectively to form a set of stent blood vessel system that is most suitable for the patient, avoiding customized stents, allowing mass production, and effectively saving time and facilitating operation.

[0136] Although the present invention has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present invention can be embodied in a variety of forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A stent graft, characterized in that: include: The stent body is a tubular structure with a coating on the surface, on which a radially concave concave portion is formed, and the stent body comprises a proximal tube body, an intermediate tube body and a distal tube body arranged in sequence from the proximal end to the distal end; the diameter of the intermediate tube body is smaller than the diameters of the proximal tube body and the distal tube body, and the intermediate tube body forms the concave portion; An outer branch, which is cantilevered outside the bracket body, one end of which is connected to the side wall of the intermediate tube body and has an inner opening on the side wall of the intermediate tube body; At least one inner branch is fitted and fixed to the inner wall of the bracket body, one end of each inner branch is connected to the side wall of the intermediate tube body, and has an outer opening on the side wall of the intermediate tube body; the outer opening is closer to the distal end than the inner opening; the number of the inner branches is two, namely the first inner branch and the second inner branch; the first inner branch has a first outer opening on the side wall of the intermediate tube body, and the second inner branch has a second outer opening on the side wall of the intermediate tube body, and the second outer opening is closer to the distal end than the first outer opening; the end of the coating is provided with a developing mark, and the developing mark is made of non-transmissive material.

2. The stent graft according to claim 1, characterized in that: The first inner branch extends from the first outer opening in a proximal direction.

3. The stent graft according to claim 2, characterized in that: The second inner branch extends from the second outer opening toward the distal direction.

4. The stent graft according to claim 3, characterized in that: As the second inner branch extends toward the distal end, the second inner branch further extends from the second outer opening along the circumference of the stent body.

5. The stent graft according to claim 2, characterized in that: As the first inner branch extends toward the proximal direction, the first inner branch further extends from the first outer opening along the circumference of the stent body.

6. The stent graft according to claim 5, characterized in that: The second inner branch extends from the second outer opening toward the proximal direction, and as it extends toward the proximal direction, the second inner branch also extends from the second outer opening along the circumference of the stent body; A direction in which the second inner branch extends along the circumferential direction is opposite to a direction in which the first inner branch extends along the circumferential direction.

7. The stent graft according to claim 1, characterized in that: The length of the outer branch is 5 mm to 20 mm.

8. The stent graft according to claim 1, characterized in that: The outer branch has a flexible section that can be flexibly deformed, and the flexible section extends outward from the inner opening.

9. The stent graft according to claim 8, characterized in that: The flexible section is made of a flexible film material.

10. The stent graft according to claim 8, characterized in that: The length of the flexible section is 2 mm to 10 mm and does not exceed 1 / 2 of the total length of the outer branch.

11. The stent graft according to claim 1, characterized in that: The outer branch and the inner branch are respectively provided with developing parts, and the developing parts are made of non-transmitting material.

12. The stent graft according to claim 11, characterized in that: The developing member is arranged along the circumferential direction at the inner opening or the outer opening.

13. The stent graft according to claim 11, characterized in that: The developing parts are respectively arranged on the outer branch or the inner branch along their respective extending directions.

14. The stent graft according to claim 11, characterized in that: The developing member is fixed by heat pressing or sewing.

15. The stent graft according to claim 1, characterized in that: The two ends of the intermediate tube body are connected to the proximal tube body and the distal tube body through a transition tube body respectively; the transition tube body has a truncated cone-shaped transition support frame for supporting the coating, and the small end of the transition support frame faces the intermediate tube body.

16. The stent graft according to claim 1, characterized in that: The proximal tube body is provided with a rear release component; the rear release component is a radially contractible annular structure, fixed on the coating, and protrudes out of the proximal edge of the coating in the proximal direction.

17. The stent graft according to claim 16, characterized in that: The rear release component is provided with barbs protruding in the circumferential direction.

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