Covered stent system for curing total aortic dissection

Abstract

The invention provides a covered stent system for curing total aortic dissection, which comprises a main stent, a large crevasse plugging device and a non-clogging blood flow branch stent, the main stent is used for blocking the crevasse, the main stent comprises a main stent skeleton and a micropore covering film, the large crevasse plugging device is wrapped in the main stent, and the micropore covering film is arranged in the main stent skeleton. The microporous stent is used for supporting the structure of a lesion position with a large crevasse, and the microporous stent is used for enabling some small branch passages to be unblocked; however, if a large crevasse exists at a non-branch position, the micropore of the micropore stent still causes the expansion of the interlayer, and at the moment, a large crevasse plugging device needs to be used. According to the invention, full aorta continuous treatment is realized: the main stent is designed to cover the whole course of thoracico-abdominal aorta and can be connected with an implanted individualized thoracico-aorta stent system to form a complete treatment scheme of the full aorta.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a endovascular stent graft system for treating total aortic dissection, particularly suitable for interventional treatment of aortic dissection involving the entire thoracic and abdominal aorta, complicated by large rupture lesions, and requiring blood supply from multiple branch arteries. Background Technology

[0002] Aortic dissection is a cardiovascular emergency with an extremely high mortality rate. Its core pathology involves a tear in the aortic intima, allowing blood to enter the media and creating two separate lumens (true and false). Without timely treatment, it can easily lead to serious complications such as aortic rupture, vessel transection, and ischemia of major organs. Approximately two-thirds of patients with thoracic and abdominal aortic dissection experience this condition. Currently, interventional treatment is the mainstream approach for aortic dissection, primarily involving the implantation of a endothelial stent graft to seal the intima tear and restore blood flow to the true lumen.

[0003] However, existing covered stent systems have many limitations: Firstly, most stents can only cover a local area of ​​the aorta (such as only covering the thoracic aorta or abdominal aorta), and the remaining rupture is followed up after surgery. However, the patient's recovery is not completely cured, which may lead to the false lumen at the unclosed rupture still increasing after a long time, increasing the risk of secondary surgery and the burden on the patient. Secondly, for large ruptures (rupture diameter > 1 cm) in the region from the superior mesenteric artery to the common iliac artery, the sealing effect of a single covered stent is poor and endoleak is likely to occur; Third, the full-coverage design of traditional stents can easily block the openings of branch arteries such as the spinal cord, kidneys, and mesentery, leading to ischemic necrosis of organs, while bare stents without lining cannot effectively seal the rupture. Fourth, it is difficult to balance the mechanical properties of the stent. If a large-diameter metal wire is used to ensure radial support, the flexibility is insufficient, making it unable to pass through tortuous blood vessels and difficult to adapt to minimally invasive surgery. If a small-diameter metal wire is used, the support is insufficient, and stent collapse is likely to occur. Fifth, the stent design at the branch of the common iliac artery lacks adaptation to the vascular anatomy, making it prone to displacement and collapse, leading to blockage of blood flow in the lower limbs.

[0004] Furthermore, existing stents are mostly standardized designs, making it difficult to match the individualized vascular morphology of different patients (such as differences in tortuosity angle and branch position), further limiting the treatment effect and only achieving a "sound improvement" outcome. Therefore, there is an urgent need for a covered stent system that can treat the entire aortic dissection, take into account both large tear closure and branch blood supply, be compatible with minimally invasive surgery, and conform to individualized vascular characteristics, in order to achieve a complete "cure" effect. Summary of the Invention

[0005] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a endovascular stent graft system for curing total aortic dissection, overcoming the following deficiencies of existing endovascular stent graft systems for total aortic dissection: Firstly, most stents can only cover a local area of ​​the aorta (such as only covering the thoracic aorta or abdominal aorta), and the remaining rupture is followed up postoperatively. Secondly, a single covered stent is unlikely to effectively seal lesions with a rupture diameter greater than 1 cm in the region from the superior mesenteric artery to the common iliac artery, which can easily lead to endoleak. Third, traditional full-coverage designs are prone to blocking branch arteries of the spinal cord, kidneys, mesentery, etc., leading to ischemic necrosis of organs; Fourth, it is difficult to balance radial support and flexibility of the stent, and large-diameter metal wires cannot be adapted to minimally invasive surgical procedures. Fifth, stents at the branches of the common iliac artery are prone to collapse, displacement, or obstruction of blood flow in the lower limbs due to unreasonable structural design. In addition, most existing stents can only be implanted locally, achieving only a "recovery" treatment effect, and cannot achieve continuous treatment of lesions in the entire aorta, or a complete "cure" treatment effect. Furthermore, there is a lack of adaptive designs for individualized vascular anatomy.

[0006] (II) Technical Solution A endovascular stent graft system for curing total aortic dissection includes: a main stent, a large tear closure device, and a non-blocking blood flow branch stent. The main stent is used to block the tear. The main stent includes a main stent skeleton and a microporous endovascular graft. The large tear closure device is encased inside the main stent and is used to provide structural support for the lesion site with a large tear. The microporous stent is used to ensure the patency of some small branch pathways. However, if a large tear exists at a non-branching location, the micropores within the microporous scaffold itself can still cause the interstitial space to expand. In this case, a large tear sealing device is needed, placed inside the microporous scaffold like a band-aid. However, since the scaffold has a wire skeleton, gaps can occur between the two scaffold layers. Therefore, the large tear sealing device requires a thicker local coating, 0.5-1mm. The main stent has a non-blocking blood flow branch stent placed at the common iliac branch to facilitate blood flow at the common iliac artery branch. The main stent is used throughout the thoracic and abdominal aorta, hence the saying that a non-blocking blood flow branch stent is placed at the common iliac branch.

[0007] Preferably, the main stent skeleton includes multiple sets of peaks, with the number of peaks being 2n (n≥3), a single stent structure, and adjacent peaks being high peaks and low peaks, in order to avoid branch pathways and have higher radial support force, so as to use smaller diameter metal wires to facilitate the implementation of minimally invasive surgery. The material of the main stent skeleton 1 is nickel-titanium alloy.

[0008] Preferably, the main support frame is arranged such that the upper and lower adjacent supports have a 180 / n deflection angle, which maximizes the clearance space and ensures that the overall support has both good flexibility and a certain axial support.

[0009] Preferably, the microporous endovascular graft has various microporous structures suitable for different thoracic and abdominal aortas. The microporous endovascular graft includes: lower microporous endovascular graft, full microporous graft, upper microporous endovascular graft, and microporous enlargement graft. Among them, the full microporous graft has a triangular microporous morphology to solve the problem of large ruptures between the mesentery and the common iliac artery. There are two treatment options for the microporous endovascular graft stent used in this segment: Option 1: There are no large ruptures at the four branches (excluding the left image), and the graft will be enlarged at these four large branch vessels; Option 2: There are large ruptures at the four branches (excluding the left image), and this graft is used for local microporous treatment; or it can be similar to the large rupture sealing device on the first page, like a band-aid.

[0010] Preferably, in order to ensure normal blood supply to the spinal cord branches, superior mesenteric branches, left and right renal branches and celiac trunk branches, the microporous membrane can expand the micropores with a balloon to form an enlarged micropore by utilizing the avoidance structure of the main scaffold skeleton.

[0011] Preferably, the microporous membrane is used in conjunction with a large-break sealing device to seal larger openings that cannot be sealed.

[0012] Preferably, the large breach sealing device includes a corrugated frame, connecting ribs, and a partial membrane.

[0013] Preferably, the non-blocking blood flow branch stent is used in combination with the upper microporous membrane. The non-blocking blood flow branch stent includes a bronchial membrane and a wave skeleton. A semi-release membrane is provided on the outside of the bronchial membrane. The non-blocking blood flow branch stent is compressed by the semi-release membrane for spatial position adjustment, and the petals are attached to the common iliac branch.

[0014] Preferably, the petal has an inner petal skeleton that does not block blood flow branches below it, and the outer petal is supported by the structure of the petal that does not block blood flow branches and is vertically turned outward.

[0015] Preferably, the bottom of the petal skeleton that does not block blood flow branches is provided with a bare stent protruding from the skeleton to prevent the branch stent from protruding and causing blood blockage.

[0016] (III) Beneficial Effects 1. Achieve continuous treatment of the entire aorta: The main stent is designed to cover the entire thoracic and abdominal aorta and can be connected to the implanted individualized thoracic aortic stent system (ZL202411260800.7) to form a complete treatment plan for the entire aorta and truly achieve the goal of "cure".

[0017] 2. Balancing large rupture sealing with branch blood supply: The combination of "microporous membrane + large rupture sealing device" can effectively seal large ruptures with a diameter greater than 1cm, reducing the risk of internal leakage, while ensuring blood flow to important branch arteries through microporous design (including triangular microporous and expandable microporous), thus avoiding organ ischemia.

[0018] 3. Optimize stent mechanical properties: The design of alternating high / low peaks and deflection angles ensures sufficient radial support and axial stability while improving the overall flexibility of the stent, enabling it to adapt to the tortuous aortic anatomical path and facilitating minimally invasive delivery.

[0019] 4. Improve branch interface stability: A branch stent with a "petal" structure and a semi-release lining was designed to address the special anatomical structure of the common iliac artery branches, achieving precise positioning and stable fit. At the same time, the bare stent protruding from the skeleton design prevents blood flow blockage and stent displacement.

[0020] 5. Enhanced individualized adaptation capability: The microporous membrane offers a variety of microporous distribution patterns (lower end, upper end, full microporous, etc.), which can be selected and combined according to the patient's specific rupture location and branch vessel distribution, improving the precision and adaptability of treatment. Attached Figure Description

[0021] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] Figure 1 This invention provides a petal-shaped framework for a endovascular stent graft system for treating total aortic dissection; 452. A diagram of a bare stent protruding from the framework; Figure 2 This is a three-dimensional structural diagram of the main stent in a stent graft system for treating total aortic dissection according to the present invention. Figure 3 This is a structural diagram of the support plate in a covered stent system for treating total aortic dissection according to the present invention; Figure 4 This is a structural diagram of the microporous endovascular membrane in a endovascular stent graft system for treating total aortic dissection according to the present invention; Figure 5 This is a plan view of the triangular micropores in a covered stent system for treating total aortic dissection according to the present invention; Figure 6 This is a structural diagram of the upper microporous membrane in a endovascular stent graft system for treating total aortic dissection according to the present invention; Figure 7 This is a three-dimensional structural diagram of a large perforation sealing device in a covered stent system for curing total aortic dissection according to the present invention; Figure 8This is a diagram showing the connection between the upper microporous lining and the non-blocking blood flow branch stent in a endovascular stent graft system for curing total aortic dissection according to the present invention. Figure 9 This is a three-dimensional structural diagram of a non-blocking stent in a covered stent system for curing total aortic dissection according to the present invention; Figure 10 This is a front view of the non-blocking blood flow branch stent in the covered stent system for curing total aortic dissection according to the present invention; Figure 11 This is a three-dimensional structural diagram of the petal-shaped skeleton and the bare stent protruding skeleton in a covered stent system for curing total aortic dissection according to the present invention; Figure 12 This is a 3D reconstruction diagram of the overall structure of the covered stent system for curing total aortic dissection according to the present invention, based on CT images. Figure 13 This invention provides a three-dimensional reconstruction structure of CT images for treating the thoracic aortic portion of total aortic dissection. Figure 14 This invention provides a CT three-dimensional reconstruction structure of the thoracic aorta and the lower segment of the thoracic aorta in the treatment of total aortic dissection; Figure 15 This invention relates to a CT three-dimensional reconstruction structure for treating the thoracic aorta, abdominal aorta, and common iliac artery portions of aortic dissection.

[0023] Legend: 1. Main stent; 2. Microporous membrane; 21. Lower microporous membrane; 22. Fully microporous; 221. Triangular microporous; 23. Upper microporous membrane; 24. Microporous enlargement; 3. Large rupture sealing device; 31. Wave-shaped skeleton; 32. Connecting rib; 33. Partial membrane; 4. Non-blocking blood flow branch stent; 41. Branch membrane; 42. Wave-shaped skeleton; 43. Semi-release membrane; 44. Petal; 45. Petal skeleton; 451. Petal skeleton; 452. Bare stent protruding skeleton. Detailed Implementation

[0024] Example 1 like Figure 1-12 As shown, the technical solution in this application embodiment addresses the problem that existing stents cannot simultaneously achieve reliable closure of large ruptures and protection of blood flow in multiple important branch arteries throughout the entire aorta. The overall approach is as follows: A endovascular stent graft system for curing total aortic dissection, with a treatment range extending 20 mm distal to the left subclavian artery branch to the common iliac artery.

[0025] Based on the anatomical characteristics of the descending aorta, a segmented treatment strategy is adopted: Upper segment treatment (Part 1): Ensure the proximal anchoring zone is greater than 20mm (if the anchoring is insufficient, an artificial blood vessel can be sutured outside the aorta using minimally invasive surgery to artificially create an anchoring zone). Micropores are pre-set in the lower segment of the stent to ensure blood supply to the spinal cord branch arteries. If the rupture is located in a spinal cord branch pathway, a large rupture closure device without a lining is implanted to compress the intima to its pre-tear position (the intima can self-repair under these conditions in the acute phase). If the rupture is located in the aorta and is large, a large rupture closure device is used for closure, with a lining thickness of 0.5-1mm.

[0026] Mid-segment treatment (Part 2): The entire stent is perforated (micro-perforated) to ensure unobstructed blood flow to the numerous small branches in this area. If there is a large tear in the main blood vessel in this area, a locally covered dense mesh stent is used for closure.

[0027] Lower segment treatment (Part 3): A perforation is made in the upper half of the stent to ensure blood supply to the celiac trunk, left and right renal arteries, and branches of the superior mesenteric artery. The treatment method is the same as in Part 1: tears at the branches are repaired by implanting a dense mesh stent through micropores; large tears in the main vessel are sealed with a locally covered stent. Perforations are also made in parts of the middle and lower segments of the stent to supply blood to branches of the left common iliac artery. If there is a lesion in this branch, it can be repaired by implanting a dense mesh stent through micropores.

[0028] The main stent framework 1 is made of nickel-titanium alloy wire through vacuum heat treatment, with 2n (n≥3) wave crests. The design of adjacent wave crests alternating between high and low peaks effectively avoids branch vessel openings while providing high radial support, allowing the use of smaller diameter wires for convenient minimally invasive delivery. The entire stent is composed of multiple such framework units connected together, with a 180 / n deflection angle between adjacent units. This design maximizes the avoidance space for branches and provides axial support through the contact points of the high and low wave crests, thus giving the stent both good flexibility and necessary axial stability.

[0029] The specific total aortic treatment plan is as follows: First, it can be used in conjunction with an authorized individualized thoracic aortic stent system (such as ZL202411260800.7) to complete the treatment of the aortic arch.

[0030] Next, the full-segment microporous stent of the present invention is implanted. Using the horizontal line of the superior mesenteric artery branch as the implantation reference, the upper end of the microporous stent can overlap with the end of the first part of the stent. For lesion areas with a rupture diameter greater than 1 cm, a large rupture sealing device 3 is used for enhanced sealing.

[0031] In the area across the renal artery, micropores are opened on the stent graft at the branch sites corresponding to the celiac trunk, superior mesenteric artery, left and right renal arteries, etc. According to the physiological structure, if there is a large rupture in this interval, the stent graft can be selected with micropores in a "pin" - shaped structure (221), and non - porous stent graft areas about 2 cm long are reserved at the upper and lower ends to enhance the sealing performance.

[0032] To ensure the stability of the connection at the common iliac artery and smooth blood flow, a non - blood - flow - blocking branch stent 4 with a "T - shaped petal" structure is used at the junction of the branch and the main blood vessel. Among them: (1) The long end is placed inside the main stent graft to strengthen the radial strength at the junction and prevent collapse at the intervals of the ordinary wavy stent. (2) The short end is a bare stent structure, extending into the main blood vessel without affecting the smooth blood flow in the main blood vessel. (3) The minimum angle between the "T - shaped petal" and the axial direction of the stent body can reach 50° to adapt to different blood vessel bifurcation angles.

[0033] The specific full - aorta treatment plan is as follows: 1. In cooperation with ZL 202411260800.7, an individualized thoracic aortic stent system, the treatment of the aortic arch is completed first.

[0034] 2. The second part is a full - segment microporous stent. Due to human differences, with the horizontal line of the superior mesenteric branch as the implantation reference, the microporous stent can overlap upward with the end of the first - part stent. Among them, for the part with a rupture larger than 1 cm, a plugging device is selected for plugging.

[0035] 3. The stent graft at the area across the renal artery opens micropores at the branch sites (celiac trunk, superior mesenteric artery, left and right renal arteries, inferior mesenteric artery). According to the physiological structure analysis, if the rupture in this interval is large, the stent graft is selected with micropores in a "pin" - shaped structure, and only 2 - cm - long non - perforated stent grafts are required at the upper and lower ends.

[0036] 4. To ensure the stability of the connection at the common iliac artery and the patency of blood flow, a "T - shaped petal" structure is adopted at the junction of the branch and the main blood vessel.

[0037] Example 2 Based on Example 1, as <The following two cases of aortic dissection were selected for clinical application: Case 1: The core lesion of patient Shang was a rupture located in the thoracic aorta region, with a spinal cord blood supply branch corresponding to the stent implantation tip. Based on the patient's individualized vascular anatomy, the treatment plan adopted the total aortic dissection covered stent system of this invention, specifically using a main branch structure with pre-prepared micropores at the tip. During the operation, the aortic arch was treated first, and then the main stent of this invention was precisely implanted, ensuring precise alignment between the micropore area at the stent tip and the opening of the spinal cord blood supply branch, ensuring unobstructed blood flow to the branch without the need for additional fenestration. Postoperative follow-up results showed that the thoracic aortic rupture was completely sealed, the false lumen was completely closed, and no complications such as endoleak occurred; the blood perfusion of the spinal cord blood supply branch was normal, and no limb sensory or motor dysfunction related to spinal cord ischemia occurred, achieving the dual goals of "rupture sealing" and "branch preservation," and the treatment effect met expectations. Case 2: Patient Chen Mou's rupture was located in the thoracic aorta and its lower segment, and the lesion area was adjacent to the opening of a branch of the superior mesenteric artery, requiring protection of the branch's blood supply. During treatment, the main stent of this invention was combined with a fully microporous endothelial graft. First, the stent was implanted in the thoracic aortic arch, and then the stent extending to the lower segment of the abdominal aorta was implanted. This ensured that the microporous graft area precisely covered the opening of the superior mesenteric artery branch, sealing the rupture in the lower thoracic aorta while maintaining the blood supply to the superior mesenteric artery. At a 3-month follow-up, the rupture was well sealed, with no endoleak, and the superior mesenteric artery blood supply was normal. No ischemia-related symptoms such as abdominal pain or indigestion occurred, further validating the adaptability and effectiveness of the microporous endothelial graft configuration of this invention for different branch areas.

[0038] Example 3 Based on Example 1, such as Figure 15 The case studies presented include two patients, Mr. Chang and Mr. Xu, with complex aortic dissections. Their lesions were extensive, with the tear located near the thoracic aorta, abdominal aorta, and common iliac artery, respectively, classifying them as typical total aortic dissections. Mr. Chang was admitted in 2013 with type A aortic dissection and underwent ascending aortic and total aortic arch replacement surgery, followed by endovascular aortic repair of the thoracic and abdominal aorta. He recovered and was discharged after 13 years of follow-up, showing excellent clinical outcomes and full recovery of his ability to work.

[0039] During the initial treatment, the patient did not undergo the full aortic coverage protocol of this invention; only the stent was implanted to cover the area above the renal artery, and the tear below the renal artery to the vicinity of the common iliac artery was not closed. Routine follow-up was conducted post-surgery. Three months post-surgery, the patient developed lower limb weakness after walking. CT angiography confirmed that the unclosed tear had persistent endoleak, leading to progressive enlargement of the false lumen, compressing the common iliac artery and lower limb blood supply branches, causing insufficient blood supply to the lower limbs and resulting in weakness. To achieve a radical cure, a second surgery was performed using the full aortic dissection endovascular stent graft system of this invention: first, the existing thoracic aortic stent was reconnected, and then the main stent of this invention was implanted to cover the entire lesion area from below the renal artery to the common iliac artery. Six months post-surgery, the patient's entire aortic tear was completely closed, the false lumen gradually thrombotic and shrank, lower limb blood supply returned to normal, the weakness after walking completely disappeared, and mobility returned to normal.

[0040] The two patients have been followed up for more than ten years to date, which verifies that the whole aortic continuous treatment program of the present invention can effectively solve the limitations of traditional local treatment programs and truly achieve the goal of "cure" of whole aortic dissection.

[0041] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A covered stent system for curing a total aortic dissection, characterized by, It comprises a main stent, a large-broken-plug device (3) and a non-blood-flow-branch-stent (4), the main stent is used to block the broken part, the main stent comprises a main stent skeleton (1) and a microporous covering film (2), wherein the large-broken-plug device (3) is wrapped in the main stent, but when there is a large broken part at a non-branch part, the microporous stent itself will cause the expansion of the dissection, at this time, the large-broken-plug device (3) is used, the thickness of the covering film of the large-broken-plug device (3) is 0.5-1mm, The main stent is provided with a non-blood-flow-branch-stent (4) at the common iliac branch, which is used for blood flow circulation at the common iliac artery branch. The main stent skeleton (1) comprises a plurality of wave crests, the number of wave crests is 2n (n≥3), a single stent structure, adjacent wave crests are high wave crests and low wave crests, and the material of the main stent skeleton (1) is nickel-titanium alloy.

2. The stent-graft system for curing a total aortic dissection according to claim 1, wherein The overall arrangement of the main stent skeleton (1) is that the adjacent stents exist a deflection angle of 180 / n.

3. The stent-graft system for treating a full aortic dissection according to claim 1, wherein The microporous covering film (2) has a plurality of distributed microporous structures suitable for different thoracic and abdominal aortas, and the microporous covering film (2) comprises a lower end microporous covering film (21), a full micropore (22), an upper end microporous covering film (23) and a microporous expansion hole (24), wherein the full micropore (22) has a triangular micropore (221) shape.

4. The stent-graft system for treating a full aortic dissection according to claim 1, wherein The microporous covering film (2) is used to ensure the normal blood supply of the spinal cord branch, the superior mesenteric branch, the left and right kidney branch and the abdominal trunk branch, and the microporous covering film (2) can form a microporous expansion hole (24) by balloon expansion of micropores by virtue of the avoiding structure of the main stent skeleton (1).

5. The stent-graft system for treating a full aortic dissection according to claim 4, wherein The microporous covering film (2) is used to seal the large broken part when the microporous covering film (2) cannot be sealed.

6. The stent-graft system for treating a full aortic dissection according to claim 1, wherein The large-broken-plug device (3) comprises a wave skeleton (31), a connecting rib (32) and a local covering film (33).

7. The stent-graft system for curing a total aortic dissection according to claim 6, wherein The non-blood-flow-branch-stent (4) is used in combination with the upper end microporous covering film (23), the non-blood-flow-branch-stent (4) comprises a branch covering film (41) and a wave skeleton (42), a half-release covering film (43) is arranged outside the branch covering film (41), the non-blood-flow-branch-stent (4) is compressed for space position adjustment by the half-release covering film (43), and a petal (44) is attached to the common iliac branch.

8. The stent-graft system for treating a full aortic dissection according to claim 1, wherein A petal (44) is arranged below the non-blood-flow-branch-stent (4), and an inner non-blood-flow-branch-stent petal skeleton (45) is arranged below the petal (44) to support the petal (44) by the structure of the outer side perpendicular to the outer turning.

9. The stent-graft system for treating a full aortic dissection according to claim 8, wherein A bare stent protruding skeleton (452) is arranged at the bottom of the non-blood-flow-branch-stent petal skeleton (45).

10. The stent-graft system for treating a full aortic dissection according to claim 1, wherein ​

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