Aortic dissection embolism system based on shape memory polymer

Abstract

The invention relates to an aortic dissection embolism system based on a shape memory polymer, and the system comprises an embolism part which is made of shape memory polymer foam and has a compressed loading state and a preset state after expansion, and the embolism part is provided with a through central cavity and an edge cavity surrounding the periphery of the central cavity; an interventional catheter for accommodating the embolic member in a loaded state to perform interventional delivery; the delivery shaft is arranged in the intervention catheter in a sliding mode and used for carrying the embolism part to be released from the far end side of the intervention catheter to the aortic dissection, the embolism part in the loading state is integrally wound around the periphery of the delivery shaft, or the delivery shaft is arranged in the central cavity in a penetrating mode. Through the structural improvement of the embolism parts and the control of the expansion starting time, the released and expanded embolism parts are arranged in order, the space filling rate is high, and the surgical treatment effect can be further improved.

Description

Technical Field

[0001] This application relates to the field of vascular interventional therapy, specifically to an aortic dissection embolization system based on shape memory polymers. Background Technology

[0002] Shape memory polymers (SMPs) are a representative type of polymer material that can play a significant role in the field of minimally invasive interventional therapy, and are particularly suitable for manufacturing filling components needed in vascular closure or embolization treatments.

[0003] Currently, shape memory polymers have begun to be tested in the treatment of aortic dissection, as embolization components. Figure 1 As can be seen, one side of the aorta 100 has an aortic dissection 110. After a covered stent 120 is implanted in the aorta 100 for support, an embolic element 200 is further implanted into the aortic dissection 110. However, in actual application, the internal space of the aortic dissection 110 is relatively long and the total volume is large. If multiple block-shaped shape memory polymers are used to fill it, these embolic elements 200 need to be released one by one, which is cumbersome. Moreover, during the release process in the body, the disordered stacking or mutual compression of these embolic elements 200 will affect the uniformity and filling rate of the filling, and create a large empty area 111 in the local area. In some existing technologies, flexible connectors are used between multiple embolic elements 200. Although they can adapt to the turning of adjacent embolic elements, the inappropriate constraint range between them will be counterproductive in spatial arrangement and ultimately affect the treatment effect. Summary of the Invention

[0004] This application provides an aortic dissection embolization system that is simple to operate and allows for further optimization of spatial layout.

[0005] This application discloses an aortic dissection embolization system based on shape memory polymers, comprising: The embolization component is made of shape memory polymer foam and has a compressed loading state and a preset state that it tends to after expansion. The embolization component has a through central cavity and an edge cavity around the outer periphery of the central cavity. An interventional catheter for receiving the embolic element in its loaded state to perform interventional delivery; The delivery shaft is slidably disposed within the interventional catheter to carry the embolic element from the distal end of the interventional catheter into the aortic dissection. In the loaded state, the embolic element is generally wrapped around the outer periphery of the delivery shaft, or the delivery shaft passes through the central lumen.

[0006] Several alternative methods are provided below, but they are not intended as additional limitations on the overall solution above. They are merely further additions or optimizations. Provided there are no technical or logical contradictions, each alternative method can be combined individually with respect to the overall solution above, or multiple alternative methods can be combined with each other.

[0007] Optionally, the plug is cylindrical in a preset state, and both the central cavity and the edge cavities penetrate the plug along the axial direction; the number of edge cavities is 3 to 13, and each edge cavity is of equal diameter and evenly distributed around the central cavity.

[0008] Optionally, the number of edge cavities is 6 to 10.

[0009] Optionally, along the radial direction of the plug, the edge cavity is located at the center of the outer edges of both the central cavity and the plug, and the space volume occupied by the plug in the preset state is 120 to 250 times that in the loaded state.

[0010] Optionally, the volume occupied by the plug in the preset state is 150 to 200 times that in the loaded state.

[0011] Optionally, in a preset state, the edge cavity has a diameter D1, the central cavity has a diameter D2, and the plug has a diameter D3; wherein D1 is 1 / 4 to 2 / 3 of D2, and D2 is 3 / 10 to 5 / 10 of D3.

[0012] Optionally, D1 can be 1 / 3 to 1 / 2 of D2.

[0013] Optional, D3 is 12~30mm.

[0014] Optionally, in the loaded state, the edge cavity is closed, the central cavity clamps the delivery shaft and both have a diameter d2, and the plug has a diameter d3; wherein d2 is 1 / 4 to 1 / 2 of d3.

[0015] Optional, d2 is 0.5~0.9mm.

[0016] Optional, d3 is 1.0~2.5mm.

[0017] Optionally, the delivery shaft passes through the plug component in the following manner: Method A: The delivery shaft penetrates the central cavity of all the plugs, and the penetration direction is consistent with the extension direction of each central cavity; or Method B: The embolizing element penetrates the central cavity of all embolizing elements. For a portion of the embolizing elements, the penetration direction is consistent with the extension direction of the central cavity, while for the remaining embolizing elements, the penetration direction is perpendicular to the extension direction of the central cavity.

[0018] Optionally, the embolization element includes: A first embolic component, wherein the delivery shaft penetrates the central cavity of the first embolic component, and the penetration direction is consistent with the extension direction of the central cavity; The second embolization component has a delivery shaft that penetrates the central cavity of the second embolization component, and the penetration direction is perpendicular to the extension direction of the central cavity; In the loaded state, the first embolic element and the second embolic element are alternately arranged along the interventional catheter.

[0019] Optionally, the plug is in a sheet-like shape when loaded and is wound around the outer periphery of the delivery shaft. In a preset state, the plug is pressed and shaped into the sheet shape in a direction perpendicular to the central cavity.

[0020] Optionally, the embolization element includes: The third embolization component, in the loaded state, has its central cavity arranged along the extension direction of the delivery shaft; The fourth embolization component, in the loaded state, has its central cavity arranged circumferentially along the delivery axis; The third and fourth embolizing elements are arranged alternately along the interventional catheter.

[0021] Optionally, the embolic components are at least two independently configured, arranged sequentially at intervals along the delivery axis in the loaded state. The outer periphery of the delivery axis is provided with radially enlarged protrusions at intervals, each protrusion located on the proximal side of the corresponding embolic component; or The embolization component is a single-piece structure, and one or at least two bundle rings are spaced apart along the axial direction, with each bundle ring dividing the embolization component into multiple unit sections.

[0022] Optionally, the plugging components are 3 to 6 independently configured.

[0023] Optionally, the number of unit sections is 3 to 6.

[0024] Optionally, the expansion start temperature of the embolization component is higher than body temperature, specifically 45°C to 60°C. The distal end of the delivery shaft is divided into a bearing section that mates with the embolic member. The bearing section is configured to be controllably energized and heated to heat the embolic member to initiate expansion.

[0025] Optionally, the expansion start temperature of the embolization component is not higher than 50°C.

[0026] Optionally, the delivery axis includes: Core rod; The heating wire is attached and fixed to the outer periphery of the core rod, and the heating wire is distributed in the bearing section; The outer casing is made of metal and has a hollowed-out area on its side wall that is suitable for bending. The outer casing wraps around the core rod and the outer periphery of the heating wire. A temperature sensing element is fixed to the outer jacket and located in the bearing section. The temperature sensing element collects the ambient temperature for corresponding control of the heating wire.

[0027] Optionally, the distal end of the outer jacket is sealed with adhesive to form a cap.

[0028] Optionally, the core rod is made of metal and has a flexible bend formed by a spiral winding at its distal end. The flexible bend extends out of the end cap and smoothly transitions with the end cap.

[0029] Optionally, the aortic dissection embolization system further includes: A power source, connected to the heating wire, provides electrical energy; The control unit receives signals from the temperature sensing element and controls the power supply accordingly to maintain the ambient temperature of the temperature sensing element at 45°C to 60°C.

[0030] This application improves the structure of the embolization component, achieving a greater expansion ratio. Combined with the control of the expansion initiation timing, the loaded embolization component can be pre-arranged regularly within the aortic dissection, and then expansion can be initiated synchronously. After the expansion is released, the embolization component is arranged in an orderly manner with a high space filling rate, which can further improve the surgical treatment effect. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A schematic diagram illustrating the filling effect of an embolization device for aortic dissection in the prior art; Figure 2 This is a schematic diagram of the end face of the embolization component (preset state) in an embolization system according to an embodiment of this application; Figure 3 for Figure 2 A schematic diagram of the engagement between the embolized plug (loaded state) and the delivery shaft; Figure 4 This is a schematic diagram illustrating the process of loading the plug component onto the delivery shaft according to an embodiment of this application; Figure 5 This is a schematic diagram illustrating the process of loading the plug onto the delivery shaft according to another embodiment of this application; Figure 6This is a schematic diagram of the engagement between a plug (loaded state) and a delivery shaft according to an embodiment of this application; Figure 7 for Figure 6 A schematic diagram of the engagement between the embolization component (preset state) and the delivery shaft; Figure 8 This is a schematic diagram of the engagement between the plug (loaded state) and the delivery shaft according to another embodiment of this application; Figure 9 for Figure 8 A schematic diagram of the engagement between the embolization component (preset state) and the delivery shaft; Figure 10 This is a schematic diagram illustrating the engagement of a plug (in a preset state) with a delivery shaft according to another embodiment of this application. Figure 11 This is a schematic diagram of the delivery shaft according to an embodiment of this application; Figure 12 for Figure 11 A schematic diagram of the outer jacket structure in the delivery shaft; Figure 13 for Figure 11 A schematic diagram of the heating wire in the delivery shaft; Figure 14 for Figure 11 A schematic diagram of the cross-section of the delivery shaft; Figure 15 This is a schematic diagram of the embolization system being delivered to the aortic dissection in one embodiment of this application. Figure 16 for Figure 15 Enlarged view of the delivery tube and plug section; Figure 17 for Figure 16 A schematic diagram of the embolization device after it has expanded to the implanted state; Figure 18 A schematic diagram showing the filling arrangement effect after the embolic component is implanted.

[0033] The component labels are as follows: 100. Aorta; 110. Aortic dissection; 111. Empty area; 120. Covered stent; 200. Embolizer; 201. Central cavity; 202. Edge cavity; 203. Unit section; 204. Bundle ring; 300, delivery shaft; 301, outward protrusion; 310, outer jacket; 311, hollow area; 312, end cap; 320, core rod; 330, heating wire; 331, positive wire; 332, negative wire; 340, temperature sensing element; 341, wire; 400. Interventional catheter. Detailed Implementation

[0034] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0035] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0037] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0038] To address the problem of excessive and disordered arrangement of embolization components in aortic dissection in existing technologies, one embodiment of this application provides an aortic dissection embolization system based on shape memory polymers. This system has opposing distal and proximal ends, and an axial direction extending between the proximal and distal ends. The proximal end generally refers to the side adjacent to the operator (e.g., a physician), and the distal end is the side relatively far away. Along the intervention path, each component itself has opposing distal and proximal ends. When the proximal and distal ends are a straight line, the axial direction is also defined, correspondingly defining the radial direction perpendicular to the axial direction and the circumferential direction arranged around the axial direction. When used to refer to a structure, "end" or "side" in this text indicates the endpoint of the structure, a point or region in that lateral direction, or a specific structure connected to that point or region.

[0039] See Figures 2-5The filling system in this embodiment includes an embolization component 200, an interventional catheter 400, and a delivery shaft 300.

[0040] The interventional catheter 400 is used to accommodate the loaded embolization element 200. The interventional catheter 400 can be made of existing materials and is suitable for interventional delivery. The inner wall of the interventional catheter 400 may have a lubricating layer. A radiopaque marker may be provided at the distal end of the interventional catheter 400 to facilitate real-time monitoring using imaging equipment. A handle may be provided at the proximal end of the interventional catheter 400 as needed. The embolization element 200 is loaded in the distal part of the interventional catheter 400. The embolization element 200 can be released to the distal side of the interventional catheter 400 in the body through relative movement with the interventional catheter 400.

[0041] The delivery shaft 300 is slidably disposed within the interventional catheter 400. The distal end of the delivery shaft 300 sequentially connects to each embolic element 200, carrying each embolic element 200 out of the distal end of the interventional catheter 400. The distal end or the entire delivery shaft 300 may be made of shape-memory metal combined with a pre-shaped design, such as a nickel-titanium alloy. During intervention, it is roughly straightened and guided through the interventional catheter 400. After detaching from the interventional catheter 400 within the body, it tends towards a pre-shaped state to adapt to the application scenario, providing optimal initial position and distribution trend for each embolic element 200, improving the initial density distribution effect and spatial regularity. The distal end of the delivery shaft 300 may be equipped with a radiopaque marker, and multiple radiopaque markers can also be spaced out in other locations.

[0042] The embolization component 200 in this embodiment uses shape memory polymer foam and has a compressed loading state and a preset state that tends to expand. Of course, although expansion occurs after implantation, it is limited by the surrounding tissue pressure and is in the implantation state of limited expansion.

[0043] The embolic component 200 is arranged along the extension direction of the interventional catheter 400 in the loaded state. The material and preparation of the embolic component 200 can be implemented using existing technologies, such as polyurethane shape memory foam. At relatively low temperatures, it can maintain its current molded shape and expand to a preset state when exposed to water and / or affected by body temperature. For example, it can be based on the polyurethane shape memory foam disclosed in Chinese patent document CN120550217A. A polyurethane acrylate prepolymer can be prepared using macromolecular polyols, diisocyanates, chain extenders containing disulfide bonds, other small molecule chain extenders, and acrylate end-capping agents. The polyurethane acrylate prepolymer, foaming agent, foaming aid, and photoinitiator are then mixed evenly to form a foaming liquid. The foaming liquid is then subjected to photocuring and foaming in sequence to obtain the polyurethane shape memory foam, which has an expansion rate of 100 to 150 times. The overall shape of the embolization component 200 is not strictly limited and can be adapted to the physiological structure of the site to be filled. For example, after full expansion, it can be in the shape of a block, specifically a cylindrical, frustum-shaped, spherical, ellipsoidal, or even various irregular shapes.

[0044] The embolic component 200 has a porous internal structure, allowing its volume to be changed through compression to suit loading and transcatheter delivery. The embolic component 200 expands within the body and occupies space at the implantation site, achieving a sealing and embolizing effect. During use, the embolic components 200 generally include, in ascending order of relative volume in their common state: The compressed loading state, for example, being housed in the interventional catheter 400 for interventional delivery; The implanted state, which expands to the preset position, is taken as an example of being released into the aortic dissection 110. After the embolization component 200 expands further relative to the loading state to complete the implantation, it can be understood as a restricted expansion, that is, it is slightly compressed under the action of the surrounding tissue. Due to the tendency to expand further, there is an interaction force between it and the surrounding tissue, and it is kept taut at the implantation site. The fully expanded preset state can be understood as the maximum volume that the plug 200 can expand to when there is no compressive force around it.

[0045] In terms of volume, without a larger cavity, the embolization component 200, relying on its own foam structure, can be 100 to 120 times larger in its preset state than in its loaded state. This application provides a larger cavity, namely, the embolization component 200 has a through central cavity 201 and an edge cavity 202 surrounding the central cavity 201. This allows the embolization component 200 to be 120 to 250 times larger in its preset state than in its loaded state. Under the same interventional size, it can occupy a larger space after expansion, for example, 150 to 200 times larger. In some cases, depending on the direction of force applied during loading and compression, the axial length in the preset and loaded states can remain essentially unchanged, with only radial expansion, and the outer diameter can be expanded to approximately 15 to 20 times. Because the expansion multiple is greater, it improves the ability to adapt to deformation to a certain extent, enabling better filling and distribution within the aortic dissection.

[0046] Combination Figure 2 , Figure 3 The embolic component 200 is cylindrical in its preset state. Both the central cavity 201 and the edge cavities 202 extend axially through the embolic component. The number of edge cavities 202 is 3 to 13, for example, 6 to 10. Each edge cavity 202 is of equal diameter and evenly distributed around the central cavity 201, achieving a relatively uniform circumferential strength and filling density distribution. Along the radial direction of the embolic component 200, the edge cavities 202 are located at the center of the outer edges of both the central cavity 201 and the embolic component 200. The volume occupied by the embolic component 200 in its preset state is 120 to 250 times that in its loaded state, for example, 150 to 200 times. The embolic component 200 can be formed by a mold, with a movable mold core set in the mold to form the central cavity 201 and the edge cavities 202.

[0047] As shown in the figure, both the central cavity 201 and the peripheral cavity 202 have circular cross-sections (the figures are for illustrative purposes only and should not be interpreted as actual relative size proportions). In the preset state, the peripheral cavity 202 has a diameter D1, the central cavity 201 has a diameter D2, and the plug 200 has a diameter D3; where D1 is 1 / 4 to 2 / 3 of D2, and D2 is 3 / 10 to 5 / 10 of D3. Further, D1 is 1 / 3 to 1 / 2 of D2. D3 is 12 to 30 mm.

[0048] In the loaded state, the edge cavity 202 is closed by the deformation of the embolic member 200, and the central cavity 201 clamps the delivery shaft 300. Both have a diameter d2. The embolic member 200 is compressed and loaded into the interventional catheter and has a diameter d3; where d2 is 1 / 4 to 1 / 2 of d3. For example, d2 is 0.5 to 0.9 mm, and d3 is 1.0 to 2.5 mm.

[0049] See Figure 4In one embodiment of this application, the plug 200 is cylindrical in a preset state, and after being compressed along one of its radial directions, it becomes sheet-like. In the loading state, the sheet-like part is rolled and wrapped around the outer periphery of the delivery shaft 300. When multiple plugs 200 are used, each plug 200 is arranged sequentially along the delivery shaft 300.

[0050] The plug 200 is wound around the delivery shaft 300. After expansion, the plug 200 is located on the side of the delivery shaft 300, which facilitates the removal of the delivery shaft 300.

[0051] The plug 200, according to its relative relationship with the delivery shaft 300 in the loaded state, includes: The third embolization component, in the loaded state, has its central cavity arranged along the extension direction of the delivery shaft; The fourth embolization component, in the loaded state, has its central cavity arranged circumferentially along the delivery axis; The third and fourth embolizing components are arranged alternately along the delivery axis 300. After the expansion is released, the fourth embolizing component can shield the central cavity of the third embolizing component, thereby improving the overall embolization effect.

[0052] See Figure 5 In one embodiment of this application, the embolization member 200 is sleeved on the delivery shaft 300 through the central cavity 201, and the load is radially pressed and wrapped around the outer periphery of the delivery shaft 300. That is, after the embolization member 200 expands, it is also sleeved on the outer periphery of the delivery shaft 300, which makes it easier to define the spatial position and reduce the misalignment and offset between multiple embolization members 200.

[0053] See Figure 6 In another embodiment of this application, the embolic member 200 is an integral structure. During processing, a mandrel with a support larger than the delivery shaft 300 is inserted into the central cavity 201 to compress the embolic member 200 to the loading state (radially compressed to a volume equivalent to the loading state). The embolic member 200 is divided into multiple unit sections 203 by the clamping rings 204 at intervals. Figure 7 In the preset state, the bundle ring 204 forms a narrowed section between adjacent unit segments 203. The bundle ring 204 can be made of a radiopaque metal material, and it can itself serve as a imaging marker, making it easy to confirm the position and spatial orientation of each unit segment 203 in real time during surgery.

[0054] See Figure 8 , Figure 9When there are multiple embolization components 200 and they are configured independently, a radiopaque mark can be set inside each embolization component 200. In order to facilitate the delivery shaft 300 to abut against each embolization component 200 for release, the outer periphery of the delivery shaft 300 is provided with radially enlarged protrusions 301 at intervals. Each protrusion 301 is located on the proximal side of the corresponding embolization component 200 and can provide auxiliary abutment support to the distal end when the interventional catheter moves relative to it. For example, the protrusion 301 is spherical and its diameter is 1.1 to 1.5 times the diameter of the delivery shaft 300.

[0055] See Figure 10 In another embodiment of this application, there are multiple plugging members 200 configured independently of each other. The plugging members 200, according to their relative relationship with the delivery shaft 300 in the loaded state, include: The first embolization component has a delivery shaft 300 that penetrates the central cavity 201 of the first embolization component, and the penetration direction is consistent with the extension direction of the central cavity 201. The second embolization component has a delivery shaft 300 that penetrates the central cavity 201 of the second embolization component, and the penetration direction is perpendicular to the extension direction of the central cavity 201. In the loaded state, the first and second embolic components are alternately arranged along the interventional catheter. Figure 10 As can be seen, the second embolizing element is located between the two first embolizing elements, which can further improve the embolizing effect.

[0056] See Figures 11-14 In this application, after the delivery shaft 300 carries all the embolic components 200 out of the interventional catheter, it initiates expansion simultaneously. This allows all the embolic components 200 (or unit segments 203) to be pre-registered to a better spatial relative position, resulting in an orderly spatial arrangement after expansion. When preparing the embolic components 200, SMP foam with a high Tg, such as around 45℃~60℃, can be selected. Under simple body temperature conditions, it will not expand significantly, providing sufficient operation time for surgery and pre-registration of spatial position. When it is necessary to expand the embolic components 200, the heating of the delivery shaft 300 can quickly and synchronously trigger the expansion of all the embolic components 200. For safety reasons, an upper limit for the heating temperature of the delivery shaft 300 can be set, such as not exceeding 50℃ (degrees Celsius). At this temperature, combined with the water absorption and permeation of the embolic components 200, they can expand rapidly, for example, in 15s~30s to reach the implantation state to complete in vivo positioning. After that, the interventional catheter and delivery shaft 300 are withdrawn from the body. At a temperature not exceeding 50°C, and in conjunction with the embolization element 200, which isolates the delivery shaft 300 from the surrounding tissue, thermal damage to the surrounding tissue can be avoided.

[0057] To control the temperature, the energizing time and power can be set based on empirical data. Furthermore, a temperature detection element 340 can be configured to detect and provide feedback on the temperature signal around the delivery shaft 300 in real time. In this embodiment, each plug 200 is wrapped around the delivery shaft 300 in the loaded state, allowing for uniform heating and better synchronization during expansion. The delivery shaft 300 includes: The core rod 320, made of metal, provides the necessary axial pushing force, and can be made of existing hard guide wires, for example. Heating wire 330 is attached and fixed to the outer periphery of core rod 320. Heating wire 330 is distributed in the bearing section of delivery shaft 300 (the part wrapped by embolization member 200 during intervention delivery). The outer jacket 310 is made of metal and has a hollow area 311 on its side wall that is suitable for bending. The hollow area 311 can be formed by laser cutting. The outer jacket 310 wraps around the core rod 320 and the heating wire 330. Temperature sensing element 340 is fixed to outer casing 310. Temperature sensing element 340 collects ambient temperature for corresponding control of heating wire 330.

[0058] The heating wire 330 may include a positive wire 331 and a negative wire 332 according to the polarity of the power supply connected to its proximal end. The positive wire 331 and the negative wire 332 are folded back at the distal end to form a circuit. Of course, the heating wire 330 and the wires extending to the proximal end for connecting to the power supply may have a sheathing layer. The power supply and control unit itself may be implemented in conjunction with existing technology. The heating power and time of the heating wire 330 are controlled accordingly based on the feedback from the temperature detection element 340.

[0059] Figure 14 As can be seen from the cross-sectional diagram, the core rod 320 is centrally located, and the positive electrode line 331 and the negative electrode line 332 are located on two opposite sides of the core rod 320 in the radial direction. There are two groups of temperature sensing elements 340, with 1 to 3 elements in each group. Each group is located on two opposite sides of the core rod 320 in the radial direction and is arranged alternately with the positive electrode line 331 and the negative electrode line 332 in the circumferential direction. Each temperature sensing element 340 extends to the proximal end through the corresponding wire 341 and is connected to the control unit.

[0060] The outer jacket 310 is made of metal for easy heat conduction, which can promptly transfer the heat of the heating wire 330 to the surrounding plug 200 to initiate expansion. The distal end of the outer jacket 310 can be sealed with adhesive to form a head 312. The core rod 320 has a flexible bend (not shown in the figure) formed by spiral winding at its distal end. The flexible bend also extends out of the head 312 and smoothly transitions with the head 312.

[0061] See Figures 15-18 In one embodiment of this application, the aortic dissection embolization system implantation process includes: Figure 15In this process, an interventional channel leading to the aortic dissection 110 is established beside the covered stent 120 via the interventional catheter 400. Embolization components 200 are exposed to the interventional catheter 400 via the delivery shaft 300. All embolization components 200 can be pre-positioned in the aortic dissection 110 by proximal withdrawal of the interventional catheter 400, distal push of the delivery shaft 300, or a combination thereof. At this point, the embolization components 200 have not yet begun to expand, thus achieving an ideal spatial arrangement and orientation under the action of the delivery shaft 300. This differs from the sequential release method in existing technologies. The expansion and random arrangement of the space are completely different. The figure uses multiple unit sections 203 as an illustration. Similarly, when multiple independently set embolic elements 200 are used, after the imaging equipment confirms that all embolic elements 200 are exposed to the interventional catheter 400 and the spatial position is as expected, the delivery shaft 300 can be driven to heat up, and all embolic elements 200 are simultaneously started to expand. Finally, the delivery shaft 300 is withdrawn. Since the embolic element 200 of this application has a larger expansion volume ratio, it can not only adapt to the shape of the surrounding tissue at the edge, but also facilitate the withdrawal of the delivery shaft 300.

[0062] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered to be within the scope of this specification. When technical features of different embodiments are embodied in the same drawing, it can be regarded as the drawing also disclosing examples of combinations of the various embodiments involved.

[0063] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. A shape memory polymer based aortic dissection embolization system, characterized in that, The application relates to an embolization device, comprising: an embolization element made of shape memory polymer foam and having a compressed loading state and a preset state to be reached after expansion, the embolization element having a through central cavity and a peripheral cavity around the central cavity; an interventional catheter for containing the embolization element in the loading state to implement interventional delivery; and a delivery shaft slidingly arranged in the interventional catheter to carry the embolization element to be released into an aortic dissection from a distal end of the interventional catheter, the embolization element in the loading state being entirely wound around the outer periphery of the delivery shaft or the delivery shaft being arranged in the central cavity. The embolization element in the preset state is cylindrical, and the central cavity and the peripheral cavity both axially pass through the embolization element; the number of the peripheral cavities is 3-13, and each peripheral cavity is equidiameter and uniformly distributed around the central cavity. In the radial direction of the embolization element, the peripheral cavities are located at the center of the outer edges of the central cavity and the embolization element, and the space volume occupied by the embolization element in the preset state is 120-250 times that in the loading state. In the preset state, the peripheral cavities have a diameter D1, the central cavity has a diameter D2, and the embolization element has a diameter D3; wherein D1 is 1 / 4-2 / 3 of D2, and D2 is 3 / 10-5 / 10 of D3.

2. The aortic dissection embolization system of claim 1, wherein, In the loading state, the central cavity tightly clamps the delivery shaft, and both have a diameter D1, the central cavity has a diameter D2, and the embolization element has a diameter D3; wherein D1 is 1 / 4-2 / 3 of D2, and D2 is 3 / 10-5 / 10 of D3.

3. The aortic dissection system of claim 2, wherein, The specific arrangement mode of the delivery shaft in the embolization element is:

4. The aortic dissection system of claim 2, wherein, Mode A, the delivery shaft passes through the central cavities of all embolization elements, and the passing direction is consistent with the extension direction of each central cavity; or 5. The aortic dissection system of claim 2, wherein the stent graft is configured to be deployed in the true lumen of the aorta. Mode B, the embolization element passes through the central cavities of all embolization elements, and for a part of the embolization elements, the passing direction is consistent with the extension direction of the central cavities, and for the rest of the embolization elements, the passing direction is perpendicular to the extension direction of the central cavities.

6. The aortic dissection system of claim 1, wherein, The embolization element in the loading state is sheet-shaped and wound around the outer periphery of the delivery shaft, and the embolization element in the preset state is pressed and shaped into the sheet shape in the direction perpendicular to the central cavity. The embolization elements are independently arranged and sequentially and spacedly arranged along the delivery shaft in the loading state, and the outer periphery of the delivery shaft is spacedly provided with radially expanded outer convex portions, and each outer convex portion is located at the proximal end side of the corresponding embolization element; or The embolization element is an integral structure and is axially and spacedly provided with one or at least two binding rings, and each binding ring divides the embolization element into a plurality of unit sections.

7. The aortic dissection system of claim 1, wherein, The expansion starting temperature of the embolization element is higher than the body temperature and is 45-60 DEG C.

8. The aortic dissection system of claim 7, wherein, The distal end part of the delivery shaft is a bearing section matched with the embolization element, and the bearing section is configured to be controllable and electrically heated for heating the embolization element to start expansion. The delivery shaft comprises:

9. The aortic dissection system of claim 1, wherein, a core rod; an electric heating wire fixedly attached to the outer periphery of the core rod, the electric heating wire being distributed in the bearing section; 10. The aortic dissection system of claim 9, wherein the stent graft is configured to be deployed in the true lumen of the aorta. an outer sleeve made of metal material and provided with a hollow region suitable for bending on the side wall, the outer sleeve being wrapped around the outer periphery of the core rod and the electric heating wire. ​ ​ ​ A temperature detecting element is fixed to the outer sleeve and located at the bearing section, which collects the ambient temperature for corresponding control of the electric heating wire.

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