Dense net support

Abstract

The invention belongs to the technical field of medical instruments, and particularly relates to a dense net support. The dense net support comprises 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 plugging section is connected with the front fixing section through a front connecting piece, and the plugging section is connected with the rear fixing section through a rear connecting piece; the plugging section is used for plugging an aneurysm position of a blood vessel, the plugging section sequentially comprises an inner layer part, a middle layer part and an outer layer part from inside to outside, the inner layer part adopts an inner layer metal stent, and the outer layer part adopts an outer layer metal stent. The dense net stent can adjust hemodynamics more accurately, and it is ensured that the blood flow of healthy blood vessels is not affected while the aneurysm is closed; the sealing effect of the aneurysm is ensured, and thrombosis is well promoted, so that blocking and healing of the aneurysm are promoted; and the endothelialization process of the stent is facilitated, so that the success rate of fusing the stent into the blood vessel is improved, the effect of completely sealing the aneurysm opening is achieved, and the recurrence risk is reduced.

Description

Technical Field

[0001] The 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 Flow Diverter 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 Flow Diverter Stents are as follows: 1. Blood flow diversion: The high-density mesh design of the Flow Diverter 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 finally the aneurysm wall closes naturally; 2. Vascular remodeling: Over time, the vascular endothelial cells in the stent grow and cover the Flow Diverter Stent to form a complete vascular endothelium, thereby closing the aneurysm orifice and reducing its recurrence risk.

[0003] In the prior art, the traditional dense mesh bracket has the following problems:

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

[0005] 2. Lack of flexibility: Traditional dense mesh stents are usually overall high-density structures with high rigidity, which are difficult to adapt to curved and complex blood vessel morphology, and are prone to cause damage to the blood 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 fusion of the stent with the blood vessel).

[0007] Therefore, it is necessary to provide an improved technical solution to address 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 occluding section is used to occlude the aneurysm position of the blood vessel. 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.

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

[0014] As described above, for the dense mesh stent, 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 described above, for the dense mesh stent, preferably, the metal coverage of the front metal stent is less 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 wavy metal wire, and an expansion stent is arranged in the cavity formed by the rear metal stent and the rear connecting piece.

[0020] As for the dense mesh bracket 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 occluding section adopts a three-layer structure design. The inner metal stent is located in the innermost circle of the occluding section. The inner metal stent adopts a high-density mesh stent, which has better support ability and closure, and provides sufficient support for the coating structure to prevent aneurysm rupture or artery collapse; the high-density inner metal stent cooperates with the coating structure to ensure the closure effect of the aneurysm, reduce blood flow entering the lesion area, reduce blood perfusion to the lesion site, 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, which makes it easier to fuse with the blood vessel 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 opening, and reduce the risk of recurrence.

[0025] The dense mesh stent is divided into three sections, and the front fixing section, the occluding section and the rear fixing section can use metal stents of different densities, so that the occluding section can provide a precise sealing effect in the aneurysm lesion area, while the front fixing section and the rear fixing 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 prior art, thereby avoiding the occluding section directly covering the opening of the side branch blood vessel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0027] Figure 1 A schematic diagram of the structure of a dense mesh stent in an embodiment of the present invention when no expansion stent is provided;

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

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

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

[0031] Figure 5An exploded structural schematic diagram for showing an expanded stent structure in one embodiment of the present invention is created;

[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 technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0035] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships 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, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to 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 the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0038] According to a specific embodiment of the present invention, Figure 1-2 As shown, the present invention provides a dense mesh stent, which includes a front fixing section 2, a blocking section 1 and a rear fixing section 3, wherein the blocking section 1 is located between the front fixing section 2 and the rear fixing section 3. The blocking section 1, the front fixing section 2 and the rear fixing section 3 are all made of a material with good biocompatibility, such as nickel-titanium alloy. The nickel-titanium alloy material can reduce the stimulation and inflammatory response to vascular endothelial cells, is conducive to the adhesion and growth of endothelial cells, and provides 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 side branch 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 the dense mesh stent, the front fixation segment 2, the occluding segment 1 and the rear fixation segment 3 can use metal stents of different densities. When occlusion is not required and the blood vessels are complicatedly curved 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 structure design, and both the inner layer 101 and the outer layer 103 adopt a metal stent structure, so that the occluding section 1 has a good occluding ability and also has sufficient supporting force; it prevents aneurysm rupture or arterial collapse, ensures that the aneurysm is effectively blocked, optimizes blood flow distribution, reduces blood perfusion to the lesion site, and promotes the occlusion and healing of the aneurysm.

[0044] The middle portion 102 adopts a coating structure, and the coating structure is located between the inner metal stent and the outer metal stent. In one embodiment of the present application, a layer of coating is sandwiched between two layers of metal stents, so that the blocking section 1 has sufficient blocking ability; a layer of coating structure is arranged between the two layers of metal stents, so that the coating structure can obtain sufficient support from the two layers of metal stents, ensuring that the coating structure can better fit the blood vessel wall carrying the aneurysm, so as to achieve complete blocking of the aneurysm part in the blood vessel as much as possible, and ensuring that the blocking part has a better blocking effect.

[0045] The metal coverage of the inner metal stent is greater than the metal coverage of the outer metal stent. In one embodiment of the present application, the inner metal stent is located in the innermost circle of the occluding segment 1. The inner metal stent adopts a high-density mesh stent, which has better support capacity and closure, and provides sufficient support for the coating structure to prevent aneurysm rupture or artery collapse; the high-density mesh stent is used to reduce the impact of blood flow on the coating structure and protect the coating structure. The occluding segment 1 adopts a three-layer design to reduce blood flow into the lesion area, reduce blood perfusion to the lesion site, and better promote thrombosis, thereby promoting the occlusion and healing of the aneurysm.

[0046] The outer metal stent is located at the outermost circle of the occlusion section 1 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, which makes it easier to fuse with the blood vessel 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 the risk of aneurysm recurrence.

[0047] The front fixing section 2 adopts a front metal stent with a single-layer structure, and the rear fixing section 3 adopts a rear metal stent with a single-layer structure. In one embodiment of the present application, since the blood vessel positions corresponding to the front fixing section 2 and the rear fixing section 3 are non-aneurysm sites, the non-aneurysm sites do not need to be blocked, nor do they need to guide the blood flow; at these locations, metal stents of appropriate density can be selected according to the fixation needs, so that the blocking section 1 can provide a precise sealing effect in the aneurysm lesion area, while the front fixing section 2 and the rear fixing section 3 can also retain the natural blood flow of healthy blood vessels as much as possible, so that the dense mesh stent can more accurately adjust the hemodynamics, ensuring that the aneurysm is blocked without affecting the blood flow of healthy blood 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 there is no blocking requirement for the front metal stent and the rear metal stent, 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 the metal coverage 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 passage in 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, so that the strength of the rear metal bracket is 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 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 arranged 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 being released, and the expansion stent 6 is connected to the rear metal stent and the rear connector 5 through 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 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 rear connector 5 and the rear metal stent increase the contact area with the inner wall of the blood vessel, 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 grid stent, and the metal coverage range of the expansion stent 6 is 20%-40%. By setting the expansion stent 6, the strength of the rear connector 5 can be increased. Since the front fixing section 2 and the front connecting section 4 are relatively flexible, they can smoothly pass through the tortuous variable diameter 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 connecting section 4 play the role of opening and guiding, and the expansion stent 6 is set to radially expand the rear connector 5 and the rear fixing section 3 to improve the anchoring effect.

[0056] like Figure 4-6 As shown, the outer surfaces of the front fixing section 2, the blocking section 1 and the rear fixing section 3 are all provided with developing points 7, and the longitudinal section of the developing point 7 is trapezoidal. The developing point 7 is provided on the front fixing section 2, the blocking section 1 and the rear fixing section 3 by welding, bonding or hot-melt connection. The developing point 7 is made of platinum or platinum-iridium alloy. Under the developing device, the developing point 7 is a light point with a different brightness from other parts, thereby assisting the doctor to judge the position of the front fixing section 2, the blocking section 1 and the rear fixing section 3. At the same time, the cross-sectional area of ​​the end of the developing point 7 with a trapezoidal cross section is large, which can increase the contact area with the blood vessel, thereby increasing the friction resistance and achieving the effect of improving stability.

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

[0058] 1. Enhance the flexibility of the stent: The elastic design of the wavy metal wire makes the stent more compliant in curved blood vessels, and can expand and contract freely without damaging the blood vessel wall, reducing the displacement of the stent after implantation or mechanical damage to the blood vessel; it is more suitable for vascular areas with complex anatomy such as intracranial arteries and carotid arteries, and 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 the traditional straight-line connection method, 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. The hemodynamics is less affected, which helps to reduce the risk of stent-related thrombosis; the wavy connection structure between the stent segments also reduces the obstruction of the stent to blood flow, especially in healthy blood vessel areas that need to maintain a higher level of blood flow patency.

[0061] 4. Maintain the stability of the stent segment: The wavy metal wire connection provides flexibility while maintaining the stability of the stent through the elastic memory property of the wavy metal wire to prevent 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 mesh stent, and the metal coverage of the high-density mesh stent ranges from 70% to 90%. In one embodiment of the present application, the high-density mesh stent can provide sufficient support and sealing to prevent aneurysm rupture or arterial collapse; and optimize blood flow distribution, reduce blood perfusion to the lesion site, ensure the sealing effect of the aneurysm, and promote thrombosis.

[0063] The outer metal stent is a low-density mesh stent, and the metal coverage of the low-density mesh stent is 20%-40%. In one embodiment of the present application, the low-density mesh stent has a lower metal coverage rate, which is more convenient for the growth of vascular endothelial cells on the low-density mesh stent, so that the vascular endothelial cells can more easily cover the low-density mesh stent after growth to form a complete endothelial layer, that is, the low-density mesh stent is more conducive to integration into the vascular endothelial layer, achieving the effect of completely closing the aneurysm orifice and reducing its recurrence risk.

[0064] It should 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: It 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. 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.

2. The dense mesh bracket according to claim 1, characterized in that: The middle layer adopts a coating structure, and the coating 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 support is greater than the metal coverage of the outer metal support.

4. The dense mesh bracket according to claim 1, characterized in that: The front fixing section adopts a front metal bracket with a single-layer structure, and the rear fixing section adopts a rear metal bracket with a single-layer structure.

5. The dense mesh bracket according to claim 4, characterized in that: The front metal support adopts an open-loop structure.

6. The dense mesh support according to claim 4, characterized in that: The metal coverage of the front metal bracket is less than the metal coverage of the rear metal bracket.

7. The dense mesh bracket according to claim 6, characterized in that: The front connecting piece between the front metal support and the blocking section is a double-layer wavy metal wire.

8. The dense mesh support according to claim 6, characterized in that: 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.

9. The dense mesh bracket according to any one of claims 1 to 8, 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.

10. The dense mesh bracket according to any one of claims 1 to 8, 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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