A dense mesh bracket

Abstract

The present invention belongs to the field of medical device technology, and specifically relates to a dense mesh stent. The dense mesh stent includes a front fixing section, a blocking section and a rear fixing section, and the blocking section is located between the front fixing section and the rear fixing section; the blocking section and the front fixing section are connected by a front connector, and the blocking section and the rear fixing section are connected by a rear connector; the blocking section is used to block the aneurysm position in the blood vessel, and the blocking section includes an inner layer, a middle layer and an outer layer from the inside to the outside, the inner layer adopts an inner layer metal stent, and the outer layer adopts an outer layer metal stent. The dense mesh stent can more accurately adjust the hemodynamics, ensuring that the aneurysm is closed without affecting the blood flow of healthy blood vessels; ensuring the sealing effect of the aneurysm, better promoting thrombosis and thus promoting the occlusion and healing of the aneurysm; and is more conducive to the endothelialization process of the stent, so as to improve the success rate of the stent integration into the blood vessel, achieve the effect of completely closing the aneurysm orifice, and reduce its recurrence risk.

Description

Technical Field

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

[0002] Flow Diverter Stents play an important role in the treatment of intracranial aneurysms, especially for complex aneurysms that cannot be effectively treated by traditional surgery or conventional stents. The design feature of the dense mesh stent is its high-density metal mesh structure, which can change the direction of blood flow, divert blood flow to healthy blood vessels, reduce blood flow in the aneurysm sac, and reduce the impact of blood flow on the aneurysm wall, thereby promoting the occlusion and healing of the aneurysm, and ultimately achieving the purpose of preventing aneurysm rupture. Among them, the specific mechanisms of the dense mesh stent are as follows: 1. Blood flow diversion: The high-density mesh design of the dense mesh stent can effectively reduce the blood flow entering the aneurysm sac, so that the aneurysm is gradually in a low-flow state, blood forms a thrombus in the aneurysm, and eventually the aneurysm wall closes naturally; 2. Vascular remodeling: Over time, the vascular endothelial cells in the stent grow and cover the dense mesh stent, forming a complete vascular endothelium, thereby sealing the aneurysm orifice and reducing its recurrence risk.

[0003] In the existing technology, the traditional dense mesh bracket has the following problems:

[0004] 1. Blockage of collateral vessels. Traditional dense mesh stents are too long and may directly cover the opening of the collateral vessels. Since the mesh of dense mesh stents is usually relatively fine, when the dense mesh stent covers the opening of the collateral vessels, it is like a fine filter that blocks the collateral vessels. Especially for some small-diameter collateral vessels, the metal wire of the stent may directly block the blood vessel entrance and block the collateral vessels.

[0005] 2. Lack of flexibility: Traditional dense mesh stents are usually of overall high-density structure, with high rigidity, making them difficult to adapt to curved and complex blood vessel morphology, and easily causing damage to the vessel wall or displacement after stent implantation;

[0006] 3. Large metal coverage area: Although the high-density metal mesh design of traditional dense mesh stents provides strong support, it also increases the metal exposure area, resulting in a higher risk of thrombosis and a slower endothelialization process; (After the stent is implanted, vascular endothelial cells will gradually grow on the surface of the stent, covering the metal structure of the stent to form a complete endothelial layer. This process is called endothelialization of the stent and is an important sign of the successful integration of the stent into the blood vessel).

[0007] Therefore, it is necessary to provide an improved technical solution to the above-mentioned deficiencies in the prior art. Summary of the Invention

[0008] The object of the present invention is to provide a dense mesh bracket to at least solve the above-mentioned problems existing in the prior art.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] A dense mesh bracket comprises a front fixing section, a blocking section and a rear fixing section, wherein the blocking section is located between the front fixing section and the rear fixing section;

[0011] The blocking section is connected to the front fixing section via a front connecting piece, and the blocking section is connected to the rear fixing section via a rear connecting piece.

[0012] The blocking section is used to block the aneurysm position of the blood vessel. The blocking section includes an inner layer part, a middle layer part and an outer layer part from the inside to the outside. The inner layer part adopts an inner layer metal stent, and the outer layer part adopts an outer layer metal stent.

[0013] As for the dense mesh stent as described above, preferably, the middle layer adopts a membrane structure, and the membrane structure is located between the inner metal stent and the outer metal stent.

[0014] As for the dense mesh stent as described above, preferably, the metal coverage of the inner metal stent is greater than the metal coverage of the outer metal stent.

[0015] As for the dense mesh stent as described above, preferably, the front fixing section adopts a front metal stent with a single-layer structure, and the rear fixing section adopts a rear metal stent with a single-layer structure.

[0016] As described above, the dense mesh stent, preferably, the front metal stent adopts an open-loop structure.

[0017] As for the dense mesh stent as described above, preferably, the metal coverage of the front metal stent is smaller than the metal coverage of the rear metal stent.

[0018] As described above, for the dense mesh stent, preferably, the front connecting piece between the front metal stent and the blocking section is a double-layer wavy metal wire.

[0019] As described above, for the dense mesh stent, preferably, the rear connecting piece between the rear metal stent and the occluding section is a single layer of wavy metal wire, and an expansion stent is provided in the cavity formed by the rear metal stent and the rear connecting piece.

[0020] As for the dense mesh stent as described above, preferably, the outer surfaces of the front fixing section, the blocking section and the rear fixing section are all provided with developing points, and the longitudinal cross-section of the developing points is trapezoidal.

[0021] As described above, the dense mesh stent, preferably, the inner metal stent is a high-density mesh stent, the metal coverage of the high-density mesh stent is in the range of 70%-90%, and the outer metal stent is a low-density mesh stent, the metal coverage of the low-density mesh stent is in the range of 20%-40%.

[0022] Beneficial effects:

[0023] In this dense mesh stent, the occlusion section adopts a three-layer structure design. The inner metal stent is located in the innermost circle of the occlusion section. The inner metal stent adopts a high-density mesh stent, which has better support capacity and sealing performance, providing sufficient support for the coating structure to prevent aneurysm rupture or arterial collapse; the high-density inner metal stent cooperates with the coating structure to ensure the sealing effect of the aneurysm, reduce blood flow into the lesion area, reduce blood perfusion to the lesion area, better promote thrombosis and thus promote the occlusion and healing of the aneurysm.

[0024] The outer metal stent is located at the outermost circle of the occlusion section and is used to fit the blood vessel wall. The outer metal stent adopts a low-density mesh stent, so that the outer metal stent can better fit the blood vessel wall to avoid blood vessel damage. Moreover, the low-density outer metal stent has a lower metal coverage rate, and its contact area with the blood vessel wall is smaller, making it easier to fuse with the blood vessel, which is more conducive to the endothelialization process of the stent, thereby improving the success rate of the stent integration into the blood vessel, achieving the effect of completely closing the aneurysm opening, and reducing the risk of recurrence.

[0025] The dense mesh stent is divided into three sections, and the front fixation section, the occluding section and the rear fixation section can use metal stents of different densities, so that the occluding section can provide a precise sealing effect in the aneurysm lesion area. At the same time, the front fixation section and the rear fixation section are used to strengthen the fixation of the occluding section, so that the length of the occluding section itself can be set shorter than the dense mesh stent in the existing technology, thereby avoiding the occluding section directly covering the opening of the side branch blood vessel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings and the accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. Among them:

[0027] Figure 1 A schematic diagram of the structure of a dense mesh stent without an expansion stent is created for an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the structure of a dense mesh stent after an expansion stent is provided in one embodiment of the present invention;

[0029] Figure 3 A schematic cross-sectional view of a plugging section in one embodiment of the present invention is provided;

[0030] Figure 4 A schematic diagram of the overall structure of a dense mesh support in one embodiment of the present invention is created;

[0031] Figure 5A schematic diagram of an exploded structure for illustrating an expandable stent structure is created for an embodiment of the present invention;

[0032] Figure 6 A schematic diagram of a developing point structure is provided for creating an embodiment of the present invention.

[0033] In the figure: 1, blocking section; 2, front fixing section; 3, rear fixing section; 4, front connecting piece; 5, rear connecting piece; 6, expansion bracket; 7, developing point; 101, inner layer; 102, middle layer; 103, outer layer. DETAILED DESCRIPTION

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present invention.

[0035] In the description of the present invention, the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0036] In the description of this application, “proximal end” refers to the end closer to the doctor during surgery, and “distal end” refers to the end farther from the doctor during surgery.

[0037] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0038] According to a specific embodiment of the present invention, Figure 1-2 As shown, the present invention provides a dense mesh stent comprising a front fixation segment 2, a blocking segment 1, and a rear fixation segment 3. The blocking segment 1 is located between the front and rear fixation segments 2 and 3. The blocking segment 1, front and rear fixation segments 2, and 3 are all made of a biocompatible material, such as nickel-titanium alloy. Nickel-titanium alloy can reduce irritation and inflammatory reactions to vascular endothelial cells, promoting their adhesion and growth, and providing a more suitable growth environment for endothelial cells.

[0039] The blocking section 1 is connected to the front fixing section 2 via a front connecting piece 4 , and the blocking section 1 is connected to the rear fixing section 3 via a rear connecting piece 5 .

[0040] By adopting a three-section design, the rear connecting piece 5 connects the occluding segment 1 and the rear fixing segment 3, and the front fixing segment 2 and the rear fixing segment 3 are used to strengthen the fixation of the occluding segment 1, so that the length of the occluding segment 1 itself can be set shorter than the dense mesh stent in the prior art, thereby avoiding the occluding segment 1 directly covering the opening of the collateral blood vessel.

[0041] like Figure 1-3 As shown, the occluding segment 1 is used to occlude the aneurysm position of the blood vessel. The occluding segment 1 includes an inner layer portion 101, a middle layer portion 102 and an outer layer portion 103 from the inside to the outside. The inner layer portion 101 adopts an inner layer metal stent, and the outer layer portion 103 adopts an outer layer metal stent.

[0042] In this dense mesh stent, the front fixation segment 2, the occlusion segment 1 and the rear fixation segment 3 can use metal stents of different densities. When there is no need for occlusion and the blood vessels are more complicatedly bent and twisted, the stents of the corresponding segments can use stents with lower density or high flexibility structures; when stable support is required, the stents of the corresponding segments can use high-density mesh stents; the segmented design can guide blood flow through the high-density segment to reduce blood perfusion in the aneurysm area; at the same time, the blood flow of normal blood vessels is maintained through the low-density segment; compared with traditional overall high-density stents, the dense mesh stent has better flexibility and adaptability, and can adjust hemodynamics more accurately, ensuring that the aneurysm is well closed while ensuring that the blood flow of normal blood vessels is not affected as much as possible.

[0043] The occluding section 1 adopts a three-layer structural design, and both the inner layer 101 and the outer layer 103 adopt a metal stent structure, which not only makes the occluding section 1 have good occluding ability, but also makes the occluding section 1 have sufficient supporting force; prevents aneurysm rupture or arterial collapse, ensures that the aneurysm is effectively occluded, optimizes blood flow distribution, reduces blood perfusion to the lesion site, and promotes the occlusion and healing of the aneurysm.

[0044] The middle section 102 comprises a membrane structure, located between the inner and outer metal stents. In one embodiment of the present application, a layer of membrane is sandwiched between the two metal stent layers, ensuring that the occluding section 1 has sufficient sealing capability. The membrane structure is positioned between the two metal stent layers, providing sufficient support from the two metal stent layers, ensuring that the membrane structure conforms more closely to the vessel wall containing the aneurysm, thereby achieving the most complete occlusion of the aneurysm within the vessel and ensuring a more effective occlusion of the occluding section.

[0045] The metal coverage of the inner metal stent is greater than that of the outer metal stent. In one embodiment of the present application, the inner metal stent is located at the innermost circle of occlusion segment 1. The inner metal stent utilizes a high-density mesh stent, which has better support and sealing properties, providing sufficient support for the membrane structure to prevent aneurysm rupture or arterial collapse. The high-density mesh stent is used to reduce the impact of blood flow on the membrane structure and protect it. Occlusion segment 1 utilizes a three-layer design to reduce blood flow into the lesion area, reduce blood perfusion to the lesion area, and effectively promote thrombosis, thereby promoting aneurysm occlusion and healing.

[0046] The outer metal stent is located at the outermost circle of the occlusion section 1 and is used to fit on the blood vessel wall. The outer metal stent adopts a low-density mesh stent, so that the outer metal stent can better fit the blood vessel wall to avoid blood vessel damage. Moreover, the low-density outer metal stent has a lower metal coverage rate, and its contact area with the blood vessel wall is smaller, making it easier to fuse with the blood vessel, which is more conducive to the endothelialization process of the stent, thereby improving the success rate of the stent integration into the blood vessel, achieving the effect of completely closing the aneurysm opening, and reducing the risk of aneurysm recurrence.

[0047] The front fixation segment 2 utilizes a single-layer front metal stent, and the rear fixation segment 3 utilizes a single-layer rear metal stent. In one embodiment of the present application, since the blood vessels corresponding to the front fixation segments 2 and 3 are non-aneurysmal sites, neither occlusion nor blood flow guidance is required in these non-aneurysmal sites. Metal stents of appropriate density can be selected based on fixation requirements at these locations, allowing the occlusion segment 1 to provide a precise closure effect in the aneurysmal lesion area while preserving the natural blood flow of healthy vessels to the greatest extent possible. This allows the dense mesh stent to more precisely adjust hemodynamics, ensuring aneurysm closure without affecting blood flow in healthy vessels.

[0048] In a preferred embodiment of the present application, the front fixing section 2 and the rear fixing section 3 are both made of memory alloy wire, which are in a compressed state before entering the blood vessel and automatically expand after being released to abut against the inner wall of the blood vessel.

[0049] Preferably, the front metal stent adopts an open-loop structure. The front metal stent with the open-loop structure is a ring with a through hole arranged along the axial direction. The open-loop structure is relatively soft, which makes the front metal stent more flexible and reduces the possibility of scratching the blood vessel wall during the distal movement.

[0050] In one embodiment of the present application, the metal coverage of the front metal stent and the rear metal stent is between that of the inner metal stent and the outer metal stent. Since the front metal stent and the rear metal stent have no blocking requirements, their metal coverage only needs to be sufficient to be fixed in the blood vessel. Therefore, less metal material can be used in non-critical areas such as the front metal stent and the rear metal stent to reduce the metal coverage area of the entire stent, thereby reducing the risk of thrombosis.

[0051] The metal coverage of the front metal stent is greater than that of the rear metal stent. In one embodiment of the present application, since the front metal stent is located at the front end of the dense mesh stent, it plays a greater role in forming a pathway within the blood vessel, which requires the front metal stent to be flexible. Therefore, the metal coverage of the rear metal stent is set to be greater than that of the front metal stent to ensure that the front metal stent has a better opening effect.

[0052] The metal coverage of the rear metal bracket is greater than that of the front metal bracket, thereby making the strength of the rear metal bracket higher, with the purpose of allowing the rear metal bracket to play a stronger supporting role.

[0053] The front connector 4 between the front metal stent and the occluding segment 1 is a double-layer wavy metal wire. In one embodiment of the present application, since the metal coverage of the front metal stent is greater than that of the rear metal stent, the supporting anchoring force of the front metal stent is greater, and the front metal stent requires a stronger connection structure. The front connector 4 uses a double-layer wavy metal wire to ensure that the connection between the front metal stent and the occluding segment 1 is more stable and firm. The rear connector 5 between the rear metal stent and the occluding segment 1 is a single-layer wavy metal wire. In one embodiment of the present application, the metal coverage of the rear metal stent is relatively small, and the rear connector 5 uses a single-layer wavy metal wire, which can minimize the influence of the metal wire on blood flow.

[0054] like Figure 2-5 As shown, an expansion stent 6 is provided in the cavity formed by the rear metal stent and the rear connector 5. The rear metal stent and the rear connector 5 form a cavity that is cylindrical in the axial direction, and the expansion stent 6 is placed in the cavity. Preferably, the expansion stent 6 is also woven from memory alloy wire, and expands radially after release. The expansion stent 6 is connected to the rear metal stent and the rear connector 5 by welding points. When in use, after the rear connector 5 and the rear metal stent are released, the expansion stent 6 expands accordingly, so that the rear connector 5 and the rear metal stent can better fit with the inner wall of the blood vessel, thereby improving the installation stability of the rear connector 5 and the rear metal stent. By arranging the expansion stent 6 at the rear connector 5 and the rear metal stent, the contact area between the rear connector 5 and the rear metal stent and the inner wall of the blood vessel is increased, thereby accelerating the endothelialization of the stent, and increasing the endothelialization efficiency of the rear connector 5 and the rear metal stent to enhance the stability of the dense mesh stent after installation.

[0055] The expansion stent 6 is a low-density mesh stent with a metal coverage range of 20%-40%. The expansion stent 6 increases the strength of the rear connector 5. Because the front fixing section 2 and the front connector 4 are relatively flexible, they can smoothly pass through the tortuous diameter-changing section. After anchoring, the passability requirements for the rear connector 5 and the rear fixing section 3 are lower than those for the front section. Therefore, the front fixing section 2 and the front connector 4 serve as opening guides, while the expansion stent 6 radially expands the rear connector 5 and the rear fixing section 3 to enhance the anchoring effect.

[0056] like Figure 4-6 As shown, the outer surfaces of the front fixing segment 2, the occluding segment 1, and the rear fixing segment 3 are each provided with a developing point 7, each with a trapezoidal longitudinal cross-section. These developing points 7 are attached to the front fixing segment 2, the occluding segment 1, and the rear fixing segment 3 by welding, gluing, or hot-melt connection. These developing points 7 are made of platinum or a platinum-iridium alloy. Under imaging equipment, these points appear as spots of light with a different brightness than other areas, assisting the physician in determining the positions of the front fixing segment 2, the occluding segment 1, and the rear fixing segment 3. Furthermore, the trapezoidal cross-section of the developing points 7 has a larger cross-sectional area at the ends, which increases the contact area with the blood vessel, thereby increasing frictional resistance and improving stability.

[0057] In this embodiment, the wavy metal wire has the following characteristics:

[0058] 1. Enhanced stent flexibility: The elastic design of the wavy metal wire makes the stent more compliant in curved blood vessels, allowing it to expand and contract freely without damaging the vessel wall, reducing stent displacement or mechanical damage to the blood vessels after implantation. It is more suitable for vascular areas with complex anatomy such as intracranial arteries and carotid arteries. The wavy connection between stent segments can effectively adapt to bends of different angles.

[0059] 2. Reduce stress concentration: The wavy design can evenly distribute the mechanical stress in the blood vessels, avoiding the local stress concentration between stent segments caused by traditional straight-line connection methods, thereby reducing the risk of local vascular damage after stent implantation; in the treatment of aneurysms and stenosis lesions, it can reduce the impact of local pressure on the lesion site and improve the long-term stability of the stent.

[0060] 3. Promote smooth blood flow: The wavy metal wire connection reduces the overall rigidity of the stent, allowing blood flow in the blood vessel to pass through the stent more smoothly, especially at the bends and twists of the blood vessels. Hemodynamics is less affected, which helps reduce the risk of stent-related thrombosis. The wavy connection structure between the stent segments also reduces the stent's obstruction to blood flow, especially in healthy blood vessel areas where high blood flow patency needs to be maintained.

[0061] 4. Maintaining the stability of the stent segment: The wavy metal wire connection provides flexibility while maintaining the stability of the stent through the elastic memory properties of the wavy metal wire, preventing the stent segment from shifting or deforming; it is beneficial for application in long-segment stent implantation or complex aneurysm treatment.

[0062] The inner metal stent is a high-density lattice stent with a metal coverage ratio ranging from 70% to 90%. In one embodiment of the present application, the high-density lattice stent can provide sufficient support and sealing to prevent aneurysm rupture or arterial collapse; it also optimizes blood flow distribution, reduces blood perfusion to the lesion, ensures aneurysm sealing, and promotes thrombosis.

[0063] The outer metal stent is a low-density mesh stent with a metal coverage range of 20%–40%. In one embodiment of the present application, the low-density mesh stent has a lower metal coverage, which facilitates the growth of vascular endothelial cells on the low-density mesh stent. After growth, the endothelial cells more easily cover the low-density mesh stent, forming a complete endothelial layer. In other words, the low-density mesh stent is more likely to integrate into the vascular endothelial layer, achieving the effect of completely sealing the aneurysm ostium and reducing the risk of recurrence.

[0064] It will be understood that the above description is merely exemplary and the embodiments of the present application do not limit this.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A dense mesh bracket, characterized in that: The dense mesh bracket includes a front fixing section, a blocking section and a rear fixing section, wherein the blocking section is located between the front fixing section and the rear fixing section; The blocking section is connected to the front fixing section via a front connecting piece, and the blocking section is connected to the rear fixing section via a rear connecting piece. The occluding section is used to occlude the aneurysm position of the blood vessel, and the occluding section includes an inner layer portion, a middle layer portion and an outer layer portion from the inside to the outside. The inner layer portion adopts an inner layer metal stent, and the outer layer portion adopts an outer layer metal stent; The front fixing section adopts a single-layer front metal bracket, and the rear fixing section adopts a single-layer rear metal bracket; The front connecting piece between the front metal bracket and the blocking section is a double-layer wavy metal wire; The rear connecting piece between the rear metal stent and the blocking section is a single-layer wavy metal wire, and an expansion stent is arranged in the cavity formed by the rear metal stent and the rear connecting piece.

2. The dense mesh bracket according to claim 1, characterized in that: The middle layer adopts a membrane structure, and the membrane structure is located between the inner metal support and the outer metal support.

3. The dense mesh bracket according to claim 2, characterized in that: The metal coverage of the inner metal bracket is greater than the metal coverage of the outer metal bracket.

4. The dense mesh bracket according to claim 1, characterized in that: The metal coverage of the front metal bracket and the rear metal bracket is between the metal coverage of the inner metal bracket and the metal coverage of the outer metal bracket.

5. The dense mesh bracket according to claim 1, characterized in that: The metal coverage of the front metal bracket is greater than the metal coverage of the rear metal bracket.

6. The dense mesh bracket according to any one of claims 1 to 5, characterized in that: The outer surfaces of the front fixing section, the blocking section and the rear fixing section are all provided with developing points, and the longitudinal cross-section of the developing points is trapezoidal.

7. The dense mesh bracket according to any one of claims 1 to 5, characterized in that: The inner metal stent is a high-density mesh stent, and the metal coverage of the high-density mesh stent is in the range of 70%-90%. The outer metal stent is a low-density mesh stent, and the metal coverage of the low-density mesh stent is in the range of 20%-40%.

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