Peripheral partial area type guiding support

Abstract

The application discloses a peripheral sub-zone type guiding stent, which comprises a proximal guiding section, a proximal aneurysm transition section, a lesion occlusion section and a distal anchoring section which are sequentially connected in the axial direction; the lesion occlusion section is divided into at least three functional sectors in the circumferential direction, each of the functional sectors has independently set metal mesh density and film state; wherein at least one of the functional sectors is a high-density film-covered sector used for aligning with an aneurysm sac to realize blood flow occlusion; at least one of the functional sectors is a large-mesh non-film sector used for aligning with a side branch vessel opening to guarantee branch blood flow. The application integrates the high-density film-covered sector and the large-mesh non-film sector on a single stent cross section through the circumferential sub-zone design, and solves the problem that the blood flow guiding stent in the prior art cannot simultaneously realize effective occlusion of an aneurysm neck and blood flow protection of a neighboring side branch vessel on the same cross section.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a peripheral segmented guide stent. Background Technology

[0002] Flow-directing stents, as important interventional devices for treating complex intracranial aneurysms, alter local hemodynamics through a high-density metal mesh structure, reducing blood flow into the aneurysm sac and thus promoting intra-aneurysmal thrombosis and endothelial occlusion. Currently, the widely used dense mesh stents in clinical practice mostly adopt a design with a uniform overall high metal coverage (usually >70%). Although they perform well in terms of occlusion, they reveal significant limitations when facing wide-necked or irregular aneurysms adjacent to important collateral vessels.

[0003] First, traditional dense-mesh stents have a continuous, dense mesh structure. Once they cover the opening of collateral vessels, their fine mesh can easily obstruct blood flow to the branches, leading to serious complications such as branch vessel occlusion, distal ischemia, or even stroke. To avoid this risk, operators are often forced to shorten the stent length or adjust the deployment position, but this may result in incomplete coverage of the aneurysm neck and insufficient blood flow shunting, thereby increasing the risk of aneurysm recurrence or rupture.

[0004] Secondly, while existing improved stents attempt to achieve axial functional zoning through a "three-segment" design (such as anterior fixation segment - occlusion segment - posterior fixation segment), for example, a dense mesh stent disclosed in an existing patent (patent number: CN 119587100A) employs a three-layer structure with a high-density inner layer and a low-density outer layer in its occlusion segment, and shortens the length of the occlusion segment to avoid collateral vessels, such solutions are still based on an axially uniform circumferential structure and cannot address common anatomical situations in clinical practice: the aneurysm neck and the opening of collateral vessels are located at different angles on the same cross-section. In this case, regardless of the axial positioning of the stent, its circumferentially uniform dense mesh structure will inevitably cover both the aneurysm neck and the collateral opening simultaneously, leading to situations where occluding the aneurysm neck will obstruct the branches, while avoiding the collateral opening will sacrifice therapeutic efficacy.

[0005] Furthermore, existing stents lack effective intraoperative positioning methods. Even with pre-designed "sparse areas," surgeons struggle to accurately identify the stent's circumferential orientation under X-ray fluoroscopy, making it impossible to ensure that the large mesh area is accurately aligned with the collateral opening. In addition, the connecting structures are mostly homogeneous wavy fibers, failing to consider the differentiated requirements for flexibility and support in different functional areas; the covering is usually a continuous circumferential layer, further exacerbating the risk of branch obstruction; and the low-flow-rate large mesh area is prone to inducing local thrombosis, lacking an active antithrombotic mechanism.

[0006] Therefore, there is an urgent need for a new type of flow-directing stent that can address the aforementioned issue that existing flow-directing stents are not suitable for wide-necked or irregular aneurysms adjacent to important collateral vessels. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a peripherally segmented guiding stent to solve the problem that the blood flow guiding stent in the prior art cannot simultaneously achieve effective occlusion of the aneurysm neck and protection of blood flow to adjacent collateral vessels on the same cross section.

[0008] To solve the above-mentioned technical problems, the present invention is implemented through the following solution:

[0009] The present invention discloses a peripherally segmented guide stent comprising a proximal guiding segment, a proximal aneurysm transition segment, a lesion occlusion segment, and a distal anchoring segment connected sequentially along the axial direction; the lesion occlusion segment is divided into at least three functional sectors along the circumferential direction, each functional sector having an independently set metal mesh density and covering state; wherein, at least one of the functional sectors is a high-density covered sector, used to align with the aneurysm sac to achieve blood flow occlusion; at least one of the functional sectors is a large-mesh, membrane-free sector, used to align with the opening of collateral vessels to ensure branch blood flow.

[0010] Preferably, the metal coverage of the high-density coated sector is 70%-90%, and the surface of the high-density coated sector is provided with a partial coating layer; the metal coverage of the large-mesh uncoated sector is ≤15%, and the mesh diameter is ≥300μm.

[0011] Preferably, the lesion occlusion segment further includes one or more transition sectors, the metal coverage of which is 40%–60%, for smoothly guiding blood flow between the high-density covered sector and the large-mesh uncovered sector.

[0012] Preferably, the proximal guiding section adopts a single-layer metal bracket with an open-loop structure and a metal coverage rate of <20%; the distal anchoring section adopts a single-layer metal bracket with a closed-loop structure and a metal coverage rate of >50%, and a self-expanding micro-anchor claw is integrated in the inner cavity of the distal anchoring section.

[0013] Preferably, differential imaging markers are provided at the boundaries between adjacent functional sectors. These markers are made of materials with different X-ray attenuation coefficients and are used to identify the orientation of each functional sector during the operation and to rotate the peripheral domain guide stent so that the large-mesh membraneless sector is aligned with the opening of the collateral vessel.

[0014] Preferably, the differential imaging marker is a wedge-shaped or trapezoidal protrusion that extends longitudinally along the outer surface of the peripheral domain guide bracket; the tip of the differential imaging marker faces the blood flow direction.

[0015] Preferably, the partial coating layer covers only the inner metal mesh surface of the high-density coated sector; the thickness of the high-density coated sector is 5-15 μm; the material of the high-density coated sector is selected from ePTFE, PLGA or their composites.

[0016] Preferably, the surface of the metal wire in the large-mesh membrane-free sector is modified with an antithrombotic bio-coating; the antithrombotic bio-coating contains at least one of heparin, CD47 mimic peptide, or phosphocholine polymer.

[0017] Preferably, the proximal transition segment and the lesion occlusion segment, as well as the lesion occlusion segment and the distal anchoring segment, are respectively connected by variable stiffness corrugated connectors; the connector connected to the high-density film-coated sector is a first connector, which has a double-layer metal wire structure; the connector connected to the large-mesh film-free sector is a second connector, which has a single-layer metal wire structure, and the outer wall of the second connector is wrapped with a flexible polymer layer.

[0018] Preferably, the peripheral segmented guide stent is made entirely of nickel-titanium shape memory alloy, and the axial length of the lesion occlusion segment is 3-12 mm; the number of functional sectors is 3, and the angle of each functional sector is 120°.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] In complex anatomical situations where the aneurysm neck and collateral vessel openings coexist in the same vascular cross-section, traditional flow-directing stents, due to their uniform circumferential structure, cannot simultaneously achieve aneurysm neck occlusion and branch protection. However, this invention, through a circumferentially segmented design, integrates a high-density covered sector and a large-mesh non-membrane sector on a single stent cross-section, solving the problem that existing flow-directing stents cannot simultaneously achieve effective occlusion of the aneurysm neck and protection of blood flow to adjacent collateral vessels on the same cross-section. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a peripheral domain-type guide bracket according to the present invention.

[0022] Figure 2 This is a schematic diagram of the lesion occlusion segment in a peripherally segmented guide stent according to the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of the distal anchoring section in a peripheral domain guide bracket according to the present invention.

[0024] Figure 4 This is a schematic diagram of the lesion occlusion segment and connecting member in the peripheral domain-type guide stent of the present invention, in a flat state.

[0025] Figure 5 This is a schematic diagram of the differential imaging mark in a peripheral domain guide bracket according to the present invention.

[0026] Figure 6 for Figure 4 Side view.

[0027] The following labels are used in the attached diagram: 1. Proximal guiding segment; 2. Proximal transition segment; 3. Lesion occlusion segment; 4. Distal anchoring segment; 5. Connector; 300. Functional sector; 301. Local coating layer; 302. Differential imaging marker; 303. Antithrombotic bio-coating; 401. Self-expanding micro-anchor; 501. First connector; 502. Second connector; 503. Flexible polymer layer; 300a. High-density coated sector; 300b. Large-mesh membrane-free sector; 300c. Transition sector. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention. Obviously, the embodiments described in this invention are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Example 1: The specific structure of the present invention is as follows:

[0031] like Figure 1 As shown, a peripherally segmented guide stent includes a proximal guiding segment 1, a proximal aneurysm transition segment 2, a lesion occlusion segment 3, and a distal anchoring segment 4 connected sequentially along the axial direction. The lesion occlusion segment 3 is divided into at least three functional sectors 300 along the circumferential direction, each of which has an independently set metal mesh density and covering state. Among them, at least one of the functional sectors 300 is a high-density covered sector 300a, used to align with the aneurysm sac to achieve blood flow occlusion; at least one of the functional sectors 300 is a large-mesh, membrane-free sector 300b, used to align with the opening of collateral vessels to ensure branch blood flow.

[0032] In this embodiment, through circumferential domain design, a high-density covered sector 300a and a large-mesh non-membrane sector 300b are integrated on a single stent cross-section, achieving coexistence of density and sparseness on a single stent cross-section. This solves the problem in the prior art that blood flow guiding stents cannot simultaneously achieve effective occlusion of the aneurysm neck and protection of blood flow to adjacent collateral vessels on the same cross-section.

[0033] like Figure 2As shown, the high-density coated sector 300a has a metal coverage rate of 70%-90%, and the surface of the high-density coated sector 300a is provided with a partial coating layer 301; the metal coverage rate of the large-mesh non-coated sector 300b is ≤15%, and the mesh aperture is ≥300μm.

[0034] In this embodiment, a critical mesh size ≥300μm is defined. This ensures free passage of red blood cells and prevents microembolism; localized coverage rather than full circumferential coverage significantly reduces the risk of branch occlusion; the parameter range is hemodynamically validated, balancing efficacy and safety. This avoids insufficient occlusion or partial obstruction of branches due to ambiguous parameters.

[0035] like Figure 4 As shown, the lesion occlusion segment 3 further includes one or more transition sectors 300c, the metal coverage of the transition sectors 300c being 40%–60%, forming a mesh density gradient, which is used to smoothly guide blood flow between the high-density covered sector 300a and the large-mesh uncovered sector 300b.

[0036] In this embodiment, existing stents lack circumferential transition design, making blood flow prone to disturbance at the dense / sparse junction. This solution achieves smooth blood flow redirection, improving hemodynamic stability and outperforming simple splicing partitioning. It avoids blood flow turbulence, eddies, or localized high shear stress caused by abrupt changes in density, reducing the risk of thrombosis.

[0037] Furthermore, the proximal guiding segment 1 adopts an open-loop single-layer metal stent with a metal coverage rate of <20%, high flexibility, and easy passage through tortuous blood vessels; the distal anchoring segment 4 adopts a closed-loop single-layer metal stent with a metal coverage rate of >50%, and integrates a self-expanding micro-anchor claw 401 in the inner cavity of the distal anchoring segment 4 for strong anchoring and anti-displacement.

[0038] In this embodiment, the miniature distal anchoring segment 4 provides active mechanical anchoring, which is superior to stents that rely solely on friction for fixation, and is particularly suitable for dilated blood vessels or areas with strong pulsation. Traditional stents have homogeneous structures at both ends, making it difficult to balance delivery permeability and distal stability.

[0039] Furthermore, a differential imaging marker 302 is provided at the boundary between adjacent functional sectors 300. The differential imaging marker 302 is made of materials with different X-ray attenuation coefficients and is used to identify the orientation of each functional sector 300 during the operation and rotate the peripheral domain guide stent so that the large mesh membraneless sector 300b is aligned with the opening of the collateral vessel.

[0040] In this embodiment, differential imaging markers 302 are set at the boundaries of each functional sector, such as platinum vs. tantalum, which show different brightness under DSA. The surgeon rotates the stent accordingly to align the large-mesh, membrane-free sector 300b with the collateral opening. Even with sparse and dense partitions, precise alignment is still impossible if the orientation cannot be identified intraoperatively. Existing stent imaging points are usually evenly distributed or only used for length positioning. This solution sets differential imaging markers 302 at the boundaries of each functional sector to achieve circumferential orientation encoding.

[0041] like Figure 5 As shown, the differential imaging mark 302 is a wedge-shaped or trapezoidal protrusion that extends longitudinally along the outer surface of the peripheral domain guide bracket; the top of the differential imaging mark 302 faces the blood flow direction.

[0042] In this embodiment, traditional circular imaging points lack fluid function and are easily displaced by blood flow. The differentiated imaging marker 302 in this solution serves not only as an imaging agent but also as a positioning and fluid guiding agent. The trapezoidal structure increases the contact area with the vessel wall, improving local stability; the guiding effect further optimizes the blood flow diversion efficiency in the occlusion area.

[0043] like Figure 6 As shown, further, the partial coating layer 301 only covers the inner metal mesh surface of the high-density coated sector 300a; the thickness of the high-density coated sector 300a is 5-15μm; the material of the high-density coated sector 300a is selected from ePTFE, PLGA or their composites.

[0044] In this embodiment, ePTFE is an inert material, and PLGA is a biodegradable material. Localized coverage is precisely limited to the occlusion area, completely avoiding branch obstruction, and the ultra-thin design maintains stent flexibility; the optional biodegradable material PLGA degrades after endothelialization, reducing the long-term risk of thrombosis.

[0045] Furthermore, the surface of the metal wire in the large-mesh membrane-free sector 300b is modified with an antithrombotic bio-coating 303; the antithrombotic bio-coating 303 contains at least one of heparin, CD47 mimic peptide, or phosphocholine polymer.

[0046] In this embodiment, existing stents mostly rely on systemic anticoagulation and lack local active antithrombotic effects; novel coatings such as CD47 mimic peptides can disguise the stent as autologous cells, achieving immune exemption, which is significantly superior to traditional heparin coatings; targeted modification is applied only to high-risk areas, avoiding the cost and biocompatibility issues associated with full stent coatings. This solves the problem of low blood flow velocity in the 300b region of the large-mesh, membrane-free sector, where metal exposure easily induces local thrombosis.

[0047] Furthermore, the proximal transition segment 2 and the lesion blocking segment 3, as well as the lesion blocking segment 3 and the distal anchoring segment 4, are respectively connected by variable stiffness corrugated connectors 5; the connector 5 connected to the high-density film-coated sector 300a is a first connector 501, which has a double-layer metal wire structure; the connector 5 connected to the large-mesh non-film-coated sector 300b is a second connector 502, which has a single-layer metal wire structure, and the outer wall of the second connector 502 is wrapped with a flexible polymer layer 503.

[0048] In this embodiment, the solution achieves connection stiffness matching with functional areas, improves overall compliance and blood flow stability, reduces metal exposure by polymer coating, lowers the risk of thrombosis near the large pore area, and solves the problem that homogeneous connectors cannot match the mechanical requirements of different sectors and are prone to stress concentration or blood flow interference at the junction of dense and sparse areas.

[0049] Furthermore, the peripheral segmented guide stent is made entirely of nickel-titanium shape memory alloy, and the axial length of the lesion occlusion segment 3 is 3-12 mm; the number of functional sectors 300 is 3, and the angle of each functional sector 300 is 120°.

[0050] In this embodiment, the number and angle range of functional sectors 300 are optimized based on clinical data. This not only distinguishes major branches but also avoids excessive segmentation that could lead to structural fragility. It also clarifies the applicable size range, enhances the feasibility and industrialization value of the solution, and uses nickel-titanium alloy and reasonable segmentation to achieve compliant release and stable anchoring of the entire stent. This ensures that the stent can automatically conform to the blood vessel, and the number of segments is sufficiently precise to adapt to clinical anatomical variations.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A peripherally segmented guide bracket, characterized in that, It includes a proximal guiding segment (1), a proximal transition segment (2), a lesion closure segment (3), and a distal anchoring segment (4) connected sequentially along the axial direction. The lesion blocking segment (3) is divided into at least three functional sectors (300) along the circumference, and each functional sector (300) has an independently set metal mesh density and coating state; Wherein, at least one of the functional sectors (300) is a high-density covered sector (300a) used to align with the aneurysm sac to achieve blood flow occlusion; At least one of the functional sectors (300) is a large-membrane-free sector (300b) used to align with the openings of collateral vessels to ensure branch blood flow.

2. The peripheral segmented guide bracket according to claim 1, characterized in that, The high-density coated sector (300a) has a metal coverage of 70%-90%, and the surface of the high-density coated sector (300a) is provided with a partial coating layer (301); the metal coverage of the large-mesh non-coated sector (300b) is ≤15%, and the mesh aperture is ≥300μm.

3. The peripheral segmented guide bracket according to claim 1 or 2, characterized in that, The lesion closure segment (3) further includes one or more transition sectors (300c), the metal coverage of which is 40%–60%, for smoothly guiding blood flow between the high-density covered sector (300a) and the large-mesh uncovered sector (300b).

4. The peripheral segmented guide bracket according to claim 1, characterized in that, The proximal guide section (1) adopts a single-layer metal support with an open-loop structure and a metal coverage rate of <20%; The distal anchoring section (4) adopts a single-layer metal bracket with a closed-loop structure and a metal coverage rate of >50%, and integrates a self-expanding micro anchor claw (401) in the inner cavity of the distal anchoring section (4).

5. The peripheral segmented guide bracket according to claim 1, characterized in that, Differential imaging markers (302) are provided at the boundaries between adjacent functional sectors (300). The differential imaging markers (302) are made of materials with different X-ray attenuation coefficients and are used to identify the orientation of each functional sector (300) during the operation and rotate the peripheral domain guide stent so that the large mesh membraneless sector (300b) is aligned with the opening of the collateral vessel.

6. The peripheral segmented guide bracket according to claim 5, characterized in that, The differential imaging mark (302) is a wedge-shaped or trapezoidal protrusion that extends longitudinally along the outer surface of the peripheral domain guide bracket; The tip of the differential imaging marker (302) faces the direction of blood flow.

7. The peripheral segmented guide bracket according to claim 2, characterized in that, The partial coating layer (301) covers only the inner metal mesh surface of the high-density coated sector (300a); The thickness of the high-density coated sector (300a) is 5-15 μm; The material of the high-density coated sector (300a) is selected from ePTFE, PLGA or their composites.

8. The peripheral segmented guide bracket according to claim 1, characterized in that, The surface of the metal wires in the large mesh non-membrane sector (300b) is modified with an antithrombotic bio-coating (303). The antithrombotic biocoating (303) contains at least one of heparin, CD47 mimic peptide, or phosphocholine polymer.

9. The peripheral segmented guide bracket according to claim 1, characterized in that, The near-tumor transition section (2) and the lesion blocking section (3), as well as the lesion blocking section (3) and the distal anchoring section (4), are respectively connected by variable stiffness corrugated connectors (5); The connector (5) connected to the high-density coated sector (300a) is a first connector (501), and the first connector (501) is a double-layer metal wire structure; The connector (5) connected to the large mesh membrane-free sector (300b) is a second connector (502). The second connector (502) is a single-layer metal wire structure, and the outer wall of the second connector (502) is wrapped with a flexible polymer layer (503).

10. The peripheral segmented guide bracket according to any one of claims 1-9, characterized in that, The peripheral domain-type guide stent is made of nickel-titanium shape memory alloy, and the axial length of the lesion occlusion segment (3) is 3-12 mm. The number of functional sectors (300) is 3, and the angle of each functional sector (300) is 120°.

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