Aorta covered stent for performing in-situ fenestration in endoluminal repair process

Abstract

The utility model provides an aorta covered stent for implementing in-situ fenestration in an intracavitary repair process, which comprises a stent and a covering membrane, the stent comprises a plurality of wave rings, the plurality of wave rings are arranged at intervals along the length direction of the stent, and the covering membrane is arranged at intervals along the length direction of the stent. The device is divided into a bare section, a reinforcing section, a membrane rupturing section and a supporting section from the near end to the far end, and the density of the membrane rupturing section, the density of the supporting section and the density of the reinforcing section are gradually increased. The membrane comprises a membrane body and a marker which are connected, the membrane body wraps the reinforcing section, the membrane breaking section and the supporting section in the circumferential direction of the stent, the marker is arranged between the membrane breaking section and the reinforcing section, the marker is arranged between the membrane breaking section and the supporting section, the membrane is easy to break, in-situ windowing is achieved, and meanwhile after the membrane is broken, the other parts are stable in structure.

Description

Technical Field

[0001] The utility model relates to the field of stent grafts, in particular to an aortic stent graft used for performing in situ fenestration in the process of intracavitary repair. Background Art

[0002] Thoracic aortic dissection (TAD) refers to a rupture in the intima of the thoracic aorta wall caused by factors such as blood flow, mechanical impact, and genetic weakness of the vascular wall. Driven by pressure, blood flows into the vascular wall through the rupture, "tearing" the originally tightly fitted vascular wall, forming a true lumen-intima sheet-false lumen dissection structure. Acute TAD is one of the more dangerous diseases in clinical practice. Due to the continued existence of the rupture, the false lumen tends to increase and spread. If it affects important branch arteries (such as the coronary artery and carotid artery) or ruptures, the patient often loses his life in a very short time.

[0003] According to the location of the aortic wall rupture, TAD can be divided into Stanford type A and type B. The former refers to the rupture in the ascending aorta, and the latter refers to the rupture in the descending aorta. The treatment of Stanford type B TAD is currently divided into two main methods: open surgery and endovascular treatment. Open surgery has a high mortality rate and postoperative complication rate due to its large trauma, long time, many complications, and high perioperative management requirements. Endovascular treatment refers to the use of interventional surgery technology to insert a covered stent into the aortic cavity, with the goal of closing the rupture, reconstructing the blood channel, and curbing the further progression of TAD. Compared with open surgery, endovascular treatment of TAD can significantly reduce the pathophysiological pressure caused by surgery, reduce in-hospital mortality and postoperative complications, and shorten the patient's postoperative recovery time.

[0004] The aortic stent graft will not only isolate the rupture, but also the opening of the branch vessels of the aorta. Endovascular treatment of TAD often requires that the stent released at the lesion site has sufficient proximal and distal anchoring areas. However, many type B aortic dissection lesions are close to the branches of the aortic arch. At this time, traditional endovascular repair technology alone cannot take into account both sufficient anchoring areas and the preservation of blood circulation in important branch vessels. In response to this situation, current solutions include hybrid surgery combined with open surgery, as well as other endovascular repair technologies, such as chimney stents, fenestrated stents, and branched stents. These new endovascular repair technologies have disadvantages such as complex operation and uncertain long-term efficacy, which limits the application of endovascular repair technology in complex TAD cases.

[0005] In situ fenestration technology refers to the technology of releasing the stent graft at the designated position, puncturing and expanding the stent graft corresponding to the branch vessel to be retained, and releasing the branch stent in the hole to retain the branch vessel, such as patents CN106923931B and CN117204978B. All steps of the in situ fenestration technology are completed in the patient's body, with a high degree of individualization, and can adapt to the anatomical structure of different patients. At the same time, in situ fenestration has a higher accuracy in determining the opening of branch vessels than in vitro fenestration.

[0006] The key points of in situ fenestration technology are the determination of the location of the easily ruptured membrane and the stability of the remaining parts of the stent structure after the membrane is ruptured. The former mainly refers to the accurate release of the stent so that the branch blood vessels to be opened fall precisely in the easily ruptured membrane area; the latter mainly refers to the coating of the remaining parts of the stent after puncture and expansion, especially the part between the puncture port and the edge of the stent needs to be guaranteed not to tear.

[0007] Based on this, there is an urgent need for an aortic stent graft that is easy to rupture the membrane and has a stable structure of the remaining parts after rupture. Utility Model Content

[0008] The utility model aims to address the deficiencies in the prior art and to provide an aortic covered stent which utilizes the membrane-breaking technology to realize in situ fenestration in a safer, more accurate and convenient manner, while maintaining a stable structure of the remaining parts after the membrane is ruptured.

[0009] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0010] Aortic stent grafts used for in situ fenestration during endovascular repair include:

[0011] A stent, wherein the stent comprises a plurality of corrugations, wherein the plurality of corrugations are arranged at intervals along the length direction of the stent, wherein the stent is divided into a bare section, a reinforcement section, a membrane-breaking section and a support section along the length direction thereof and from the proximal end to the distal end, wherein the density of the membrane-breaking section, the support section and the reinforcement section gradually increases;

[0012] The covering film comprises a film body and a marking body connected to each other, the film body wraps the reinforcement section, the membrane-breaking section and the support section along the circumferential direction of the stent, and the marking body is respectively arranged between the membrane-breaking section and the reinforcement section and the support section.

[0013] As a preferred embodiment, the supporting section includes at least two corrugations with different densities.

[0014] As a preferred embodiment, the lengths of the reinforcement section, the bare section, the membrane-breaking section and the supporting section gradually increase.

[0015] As a preferred embodiment, the membrane body and the marking body are woven.

[0016] As a preferred embodiment, the marker is arranged around the circumference of the stent.

[0017] As a preferred embodiment, marking points are provided on the reinforcement section.

[0018] As a preferred embodiment, the marking point is located between the bare section and the reinforced section.

[0019] As a preferred embodiment, there are multiple marking points, which are arranged at intervals around the circumference of the bracket.

[0020] Compared with the prior art, this technical solution has the following advantages:

[0021] The design of weaving markers into the membrane allows surgeons to clearly identify the position of the proximal end of the stent coating and the easily ruptured membrane area in DSA images, increasing the accuracy and safety of in situ fenestration surgery; the metal stents in the easily ruptured membrane segment are more sparsely distributed and the wave intervals are wider, reducing the probability of the metal stent affecting puncture.

[0022] The proximal application of a bare segment can widen the proximal anchoring area of ​​the stent while ensuring blood flow in the branch artery, thereby broadening the indications and making it suitable for patients whose dissection is close to the branches above the aortic arch.

[0023] A reinforcement section is designed at the proximal end of the membrane rupture segment, which can play a reinforcing role and prevent the proximal tearing of the membrane caused by window puncture; it also has higher compliance and smaller vascular force, reducing the complication rate of proximal internal leakage and reverse tearing.

[0024] The overall size of the stent is not limited, and there are many sizes of diameter and distal length, which is suitable for patients with different ranges of lesions.

[0025] The present invention is further described below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the structure of the aortic stent graft used for in situ fenestration during endovascular repair according to the utility model;

[0027] Figure 2 It is a structural schematic diagram of the bracket of the utility model.

[0028] In the figure: 100 support, 110 wave ring, 1001 bare section, 1002 reinforcement section, 1003 broken membrane section, 1004 support section, 1005 marking point, 200 covering film, 210 membrane body, 220 marking body. DETAILED DESCRIPTION

[0029] The following description is used to disclose the utility model so that those skilled in the art can implement the utility model. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the utility model defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the utility model.

[0030] like Figure 1 and Figure 2 As shown, the aortic stent graft for performing in situ fenestration during endovascular repair comprises:

[0031] A stent 100, wherein the stent 100 comprises a plurality of corrugations 110, wherein the plurality of corrugations 110 are arranged at intervals along the length direction of the stent 100, and the stent 100 is divided into a bare section 1001, a reinforcement section 1002, a membrane-breaking section 1003 and a support section 1004 along the length direction thereof and from the proximal end to the distal end, wherein the densities of the membrane-breaking section 1003, the support section 1004 and the reinforcement section 1002 gradually increase;

[0032] The coating 200 includes a film body 210 and a marking body 220 connected to each other. The film body 210 wraps the reinforcement section 1002, the membrane-breaking section 1003 and the support section 1004 along the circumferential direction of the stent 100. The marking body 220 is respectively arranged between the membrane-breaking section 1003 and the reinforcement section 1002 and the support section 1004.

[0033] The bare segment 1001 can widen the proximal anchoring area of ​​the stent while ensuring the blood flow of the branch artery without affecting the blood flow of the proximal branch of the lesion, thereby broadening the indications and making it suitable for patients whose dissection is close to the branches on the aortic arch. The metal stent density of the membrane-breaking segment 1003 is the smallest, and it is easy to break the membrane. The marker 220 is respectively arranged between the membrane-breaking segment 1003 and the reinforcement segment 1002 and the support segment 1004, which can clearly indicate the position of the easily broken membrane area in DSA, so that the surgeon can locate the easily broken membrane area to the opening of the branch vessel to be retained when the stent is released, and the easily broken membrane area can also be clearly selected during puncture. At the same time, the reinforcement segment 1002 is arranged between the membrane-breaking segment 1003 and the bare segment 1001, and the density of the reinforcement segment 1002 is the largest, which can play the role of reinforcing the boundary and effectively prevent the tearing of the covering film to the proximal end of the stent after puncture. The support segment 1004 has sufficient support effect on the distal true cavity.

[0034] like Figure 1 and Figure 2As shown, the diameter of the stent 100 is 20 to 44 mm to adapt to the anatomical structure of different patients. The length of the stent 100 ranges from 100 to 240 mm, and the appropriate length can be selected according to the cumulative range of the lesions. The wave coil 110 of the stent 100 is made of metal wire material, including nickel-titanium alloy, etc. From the proximal end to the distal end, different segments of the coated stent have different functions, which are described as follows in conjunction with the accompanying drawings:

[0035] refer to Figure 1 The bare segment 1001 has no coating on its surface and is approximately 20 mm long. In this embodiment, the bare segment 1001 has one wave ring 110. By providing the bare segment 1001, while covering more possible anchoring areas, the blood supply of the branch vessels can be taken into consideration, thereby broadening the indications for surgery.

[0036] The anchoring area provides a stable support for the aortic stent graft. The stent is tightly integrated with the aortic wall through the anchoring area, thus ensuring the stability and durability of the stent in the body.

[0037] refer to Figure 1 The metal stent of the reinforcement section 1002 has the highest density, which can play the role of reinforcing the boundary and effectively prevent the film from tearing toward the proximal end of the stent after puncture at the membrane rupture section 1003. The density of the reinforcement section 1002 is the highest, which means that the amplitude of the wave coil 110 of the reinforcement section 1002 is small and dense. It can be reflected by parameters such as amplitude and wavelength. When the amplitude and wavelength of the section are the largest and the distance between the wave coils is large, the density is the smallest, and when the amplitude and wavelength are the smallest and the distance between the wave coils is small, the density is the largest. In this embodiment, the number of the wave coil 110 of the reinforcement section 1002 is one, and its length is 5 mm.

[0038] In the entire stent 100, the wave amplitude and wavelength of the wave coil 110 of the reinforcement section 1002 are the smallest, which can prevent the film of the ruptured membrane section 1003 from tearing toward the proximal end after puncture, and the metal stent with small wave amplitude has better compliance and less pressure on the blood vessel, which can prevent postoperative complications caused by poor proximal adhesion of the stent or tearing of the blood vessel.

[0039] refer to Figure 1 , a marking point 1005 is arranged between the reinforcement sections 1002, which can be clearly developed in DSA to clearly indicate the starting position of the membrane rupture section 1003 when released. In this embodiment, the marking point 1005 is located between the bare section 1001 and the reinforcement section 1002, and the number of the marking points 1005 is multiple, and they are arranged at intervals around the circumference of the stent 100.

[0040] The endovascular treatment of aortic dissection involves the step of stent release, during which the stent needs to be accurately positioned relative to the various structures of the aorta, especially the position of the proximal anchor point. Once the stent is fully released, it will be difficult to adjust the position of the stent. DSA can visualize metal stents, but they are relatively thin and not obvious. Therefore, the stent is designed with a reinforcement section 1002 made of a slightly denser metal material at the proximal starting section of the membrane rupture section 1003, and a marking point 1005 thereon, which can fully indicate the proximal starting point of the membrane during the operation, thereby improving the accuracy of the operation.

[0041] refer to Figure 1 The density of the metal stent of the membrane-breaking section 1003 is the smallest, that is, compared with other sections of the stent 100, the amplitude and wavelength of the wave ring 110 of the membrane-breaking section 1003 are the largest, thus avoiding the dense stents from blocking puncture. As a preferred embodiment, the membrane body 210 of the membrane-breaking section 1003 can be made of easily ruptured materials, including polyester and the like.

[0042] In this embodiment, the length of the membrane-breaking section 1003 is 40 mm, and the number of its corrugations 110 is two. The interval between two adjacent corrugations 110 is large, so that the corrugations 110 of the membrane-breaking section 1003 are sparsely distributed.

[0043] refer to Figure 1 A marker 220 is provided between the membrane-breaking section 1003 and the reinforcement section 1002 and the support section 1004, respectively, which can clearly indicate the position of the easily ruptured membrane area in DSA, so that the surgeon can locate the easily ruptured membrane area to the opening of the branch vessel to be retained when the stent is released, and the easily ruptured membrane area can also be clearly selected during puncture.

[0044] Furthermore, the marker 220 is arranged around the circumferential direction of the bracket 100, that is, the marker 220 is ring-shaped, which increases the size of the marker 220 in the circumferential direction and facilitates checking its position in DSA.

[0045] In the in situ fenestrated aortic endovascular treatment surgery, it is necessary to puncture, expand and establish the guidewire track of the stent coating by means of guidewire, puncture needle, radiofrequency ablation, etc. The easily punctured membrane has been improved in materials science and textile technology, which ensures the strength of the coating while reducing the difficulty of puncture and the complication rate. However, in actual surgery, firstly, it is impossible to distinguish between conventional coatings and existing easily punctured coatings under DSA imaging, and surgeons cannot clearly identify the puncturable area, which increases the difficulty and risk of the operation; secondly, if the puncture port is close to the proximal end of the coating, it may cause tearing from the puncture port to the proximal end of the coating, causing complications such as internal leakage; in addition, the easily punctured membrane area is also supported by metal stents due to structural strength requirements. If the metal stents are too dense, it will increase the probability that the intended puncture point is interfered by the metal stent, affecting the surgical effect. Therefore, the present stent is provided with markers 220 at both ends of the easily ruptured membrane area, which can clearly indicate the position of the easily ruptured membrane area in DSA, so that the surgeon can position the easily ruptured membrane area to the opening of the branch blood vessel to be retained when the stent is released, and can also clearly select the easily ruptured membrane area during puncture. At the same time, the present stent has another 5 mm long reinforcement section 1002 at the proximal end of the easily ruptured membrane. The metal stent in this section has a small wave amplitude and is fine as a whole, which can play a role in reinforcing the boundary and effectively prevent the tearing of the coating toward the proximal end of the stent after puncture. Small-amplitude waves can also increase the compliance of the stent opening, reduce the stress of the metal stent on the blood vessel, and reduce the occurrence of postoperative complications such as internal leakage and reverse tearing of blood vessels. In addition, compared with the conventional coating section, the distribution and wave amplitude of the wave circles 110 of the membrane rupture section 1003 of the present stent are more sparse, providing surgeons with as many easily punctured areas as possible.

[0046] Preferably, the membrane body 210 and the marking body 220 are woven to improve the connection strength between the two. Specifically, the marking body 220 is made of metal wire and is woven into one with the membrane body 210.

[0047] refer to Figure 1 The support segment 1004 has sufficient supporting effect on the distal true cavity, and its length is about 35 to 175 mm.

[0048] Preferably, the support segment 1004 includes at least two wave rings 110 of different densities, which are arranged at intervals to improve the support strength of the support segment 1004.

[0049] After TAD is formed, the false lumen of the vessel may compress the true lumen due to the impact of blood flow or thrombosis, which may weaken the blood supply of the true lumen. Therefore, in addition to sealing the vascular rupture, another important aspect of TAD endovascular treatment is to provide sufficient support for the true lumen of the distal vessel to ensure the blood supply of the body.

[0050] From the above, it can be seen that the lengths of the reinforcement section 1002, the bare section 1001, the membrane-breaking section 1003 and the support section 1004 gradually increase, and the density of the metal brackets of the membrane-breaking section 1003, the support section 1004 and the reinforcement section 1002 gradually increases.

[0051] Similar to conventional aortic interventional treatment, the stent can be delivered to a specific location through the femoral artery puncture port with a suitable delivery system. During proximal release, the position of the stent anchor can be adjusted according to the positions of the dense marking points 1005 and the markers 220 at both ends of the easily ruptured membrane displayed in the DSA during semi-release. At the same time, since there is a bare segment 1001 at the proximal end, sufficient proximal anchoring area can be occupied without affecting the blood supply of the proximal branch vessels. After the main body of the stent is released, different puncture and membrane rupture methods can be selected according to the intraoperative situation and objective conditions. The membrane is punctured, the balloon is expanded, the guidewire is used to establish a track, and the branch vessel stent is placed between the two markers 220 and in the area corresponding to the branch vessel to be reconstructed. Finally, the intravascular treatment of Stanford type B aortic dissection is achieved.

[0052] In summary, the design of braiding the membrane body 210 and the marker body 220 allows surgeons to clearly identify the location of the proximal end of the stent coating and the easily ruptured membrane area in the DSA image, thereby increasing the accuracy and safety of the in situ fenestration surgery; the metal stents in the easily ruptured membrane segment are more sparsely distributed and the wave intervals are wider, reducing the probability of the metal stent affecting the puncture. The proximal bare segment 1001 can be used to widen the proximal anchoring area of ​​the stent while ensuring the blood flow of the branch artery, broadening the indications and making it suitable for patients whose dissection range is close to the branches on the aortic arch. A reinforcement segment 1002 is designed at the proximal end of the ruptured membrane segment 1003, which can play a reinforcing role and prevent the coating from tearing toward the proximal end due to the fenestration puncture; it also has higher compliance and smaller vascular forces, reducing the complication rate of proximal internal leakage and reverse tearing. The overall size of the stent is not limited, and there are many sizes of diameter and distal length, which is suitable for patients with different ranges of lesions.

[0053] The embodiments described above are only used to illustrate the technical ideas and features of the utility model, and their purpose is to enable technicians in this field to understand the content of the utility model and implement it accordingly. The patent application scope of the utility model cannot be limited only by this embodiment, that is, any equivalent changes or modifications made according to the spirit disclosed by the utility model still fall within the patent scope of the utility model.

Claims

1. An aortic stent graft for performing in situ fenestration during endovascular repair, characterized in that: include: A stent (100), wherein the stent (100) comprises a plurality of corrugations (110), wherein the plurality of corrugations (110) are arranged at intervals along the length direction of the stent (100), and the stent (100) is divided into a bare section (1001), a reinforcement section (1002), a membrane-breaking section (1003), and a support section (1004) along its length direction and from the proximal end to the distal end, and the densities of the membrane-breaking section (1003), the support section (1004), and the reinforcement section (1002) gradually increase; The covering film (200) comprises a film body (210) and a marking body (220) connected to each other, the film body (210) wraps the reinforcing section (1002), the membrane-breaking section (1003) and the supporting section (1004) along the circumferential direction of the stent (100), and the marking body (220) is provided between the membrane-breaking section (1003) and the reinforcing section (1002) and the supporting section (1004).

2. The aortic stent graft for in situ fenestration during endovascular repair according to claim 1, characterized in that: The support section (1004) includes at least two wave rings (110) of different densities.

3. The aortic stent graft for in situ fenestration during endovascular repair according to claim 1, characterized in that: The lengths of the reinforcement section (1002), the bare section (1001), the membrane-breaking section (1003) and the supporting section (1004) gradually increase.

4. The aortic stent graft for in situ fenestration during endovascular repair according to claim 1, characterized in that: The membrane body (210) and the marking body (220) are woven.

5. The aortic stent graft for in situ fenestration during endovascular repair according to claim 1, characterized in that: The marker (220) is arranged around the circumferential direction of the bracket (100).

6. The aortic stent graft for in situ fenestration during endovascular repair according to claim 1, characterized in that: The reinforcement section (1002) is provided with a marking point (1005).

7. The aortic stent graft for in situ fenestration during endovascular repair according to claim 6, characterized in that: The marking point (1005) is located between the bare section (1001) and the reinforced section (1002).

8. The aortic stent graft for in situ fenestration during endovascular repair according to claim 6, characterized in that: The number of the marking points (1005) is plural, and they are arranged at intervals in the circumferential direction of the bracket (100).

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