Covered stent and balloon expansion system

Abstract

This invention provides a covered stent and a balloon dilation system. The balloon dilation system includes a covered stent and a balloon catheter. The balloon catheter includes a tube body, a balloon base, and an anti-slip component. The balloon base is fixed to the distal end of the tube body, and the inner lumen of the balloon base communicates with the inner lumen of the tube body. The anti-slip component is applied to the outer surface of the balloon base and includes multiple first protrusions protruding away from the balloon base. The multiple first protrusions are opposite to the first spaced covered portion and at least restrict the axial slippage of the supporting skeleton. The first protrusions limit the axial slippage of the covered stent, preventing slippage. Furthermore, the balloon catheter can assist the covered stent in forming a shape close to the bifurcation branch segment of a bifurcation vessel at its proximal end with another stent, thereby preventing vascular occlusion.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a covered stent and balloon dilation system. Background Technology

[0002] With the development of modern medical technology, implantation of internal prostheses has become a treatment method for most cardiovascular diseases, among which balloon-expandable stents have become a common and important surgical treatment method.

[0003] During delivery, balloon-expandable stents are prone to slippage and dislodgement. Additionally, as the balloon expands, uneven release of the stent can lead to uneven release of the stent, affecting the accuracy of the stent's placement and the integrity of its shape. Summary of the Invention

[0004] Therefore, it is necessary to provide a covered stent and balloon dilation system that can ensure the uniformity of stent release while ensuring that the stent is delivered without displacement or slippage.

[0005] A coated support structure is provided, wherein the coated support structure is a tubular structure with openings at both ends. The coated support structure includes a main support structure, and the surface of the main support structure is coated with a surface film. The main support structure includes a plurality of support skeletons, which are spaced apart along the axial direction of the coated support structure. A first spaced coated portion is formed between two adjacent support skeletons, and the two adjacent support skeletons are connected through the first spaced coated portion.

[0006] In one embodiment, the proximal side of the main support includes a bare support, which includes a first support portion and a second support portion in the circumferential direction, wherein the radial support force of the first support portion is greater than the radial support force of the second support portion.

[0007] A balloon dilation system includes the aforementioned covered stent and balloon catheter. The balloon catheter includes a tube body, a balloon base, and an anti-slip component. The balloon base is fixed to the distal end of the tube body, and the inner lumen of the balloon base communicates with the inner lumen of the tube body. The anti-slip component is applied to the outer surface of the balloon base and includes a plurality of first protrusions protruding away from the balloon base. The plurality of first protrusions are opposite to the first spaced covered portion and at least restrict the axial slippage of the support frame.

[0008] In one embodiment, a plurality of first protrusions are spaced apart along the axial direction of the anti-slip component, and the axial distance between two axially adjacent first protrusions is greater than the axial length of the support frame, and less than the sum of the axial distance between the two first protrusions and the axial length of the support frame between the two first protrusions.

[0009] In one embodiment, the anti-slip component includes a contact portion other than the first protrusion, the radial thickness of the contact portion being less than the radial thickness of the first protrusion, and the surface roughness of the contact portion being less than the surface roughness of the first protrusion.

[0010] In one embodiment, the anti-slip component includes a plurality of second protrusions, the second protrusions being disposed on the contact portion and protruding from the outer surface of the contact portion, the radial thickness of the second protrusions being less than the radial thickness of the first protrusions.

[0011] In one embodiment, the anti-slip component includes an outer cover layer, an inner cover layer, a restraining member, and an intermediate member. The inner cover layer is attached to the outer surface of the balloon substrate, the outer cover layer covers the outer surface of the inner cover layer, the restraining member is disposed between the outer cover layer and the inner cover layer to form a first protrusion on the surface of the outer cover layer, and the intermediate member is disposed between the outer cover layer and the inner cover layer to form a second protrusion on the surface of the outer cover layer.

[0012] In one embodiment, the constraint member and the intermediate member are respectively set independently or the constraint member and the intermediate member are integrally formed.

[0013] In one embodiment, the anti-slip component includes two retaining rings, the outer cover layer and the inner cover layer are vacuum-adsorbed, and the axial ends of the outer cover layer and the inner cover layer are respectively sealed and fixed to the axial ends of the balloon base by one of the retaining rings.

[0014] In one embodiment, the balloon matrix includes a support mounting portion located between the two ends of the balloon matrix in the axial direction. The proximal side of the support mounting portion includes a deformable portion. When the balloon matrix is ​​in an expanded state, any radial cross-section of the deformable portion is a semi-circular cross-section.

[0015] In one embodiment, when the coated bracket is mounted on the bracket mounting portion, the bare bracket is mounted on the deformable portion, and the first support portion is located on the semi-circular arc side of the semi-circular cross-section.

[0016] The beneficial effects of this invention are as follows: Compared with the prior art, this invention provides a covered stent and a balloon dilation system. The balloon dilation system includes a covered stent and a balloon catheter. The balloon catheter includes a tube body, a balloon base, and an anti-slip component. The balloon base is fixed to the distal end of the tube body, and the inner lumen of the balloon base communicates with the inner lumen of the tube body. The anti-slip component is covered on the outer surface of the balloon base and includes multiple first protrusions protruding away from the balloon base. The multiple first protrusions are opposite to the first spaced covered portion and at least restrict the axial slippage of the support skeleton. The first protrusions limit the axial slippage of the covered stent, preventing slippage. Furthermore, the balloon catheter can assist the covered stent in forming a shape close to the bifurcation branch segment of the bifurcation vessel at the proximal end with another stent, thereby preventing the formation of vascular occlusion. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a covered stent implanted in a bifurcation blood vessel in the prior art of this invention;

[0018] Figure 1a This is a schematic diagram of a closed residual cavity structure formed at the proximal end of a covered stent at a vascular bifurcation in the prior art of this invention;

[0019] Figure 2 This is a schematic diagram of the balloon dilation system in Embodiment 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of the film-coated scaffold structure in Embodiment 1 of the present invention;

[0021] Figure 4 This is a schematic diagram of the supporting skeleton structure in Embodiment 1 of the present invention;

[0022] Figure 5 For the present invention Figure 4 A magnified schematic diagram of the structure at position A in the middle;

[0023] Figure 6 This is a schematic diagram of a transition mesh structure provided for the supporting skeleton in one embodiment of the present invention;

[0024] Figure 7 For the present invention Figure 6 A magnified schematic diagram of the structure at position B in the middle;

[0025] Figure 8 This is a schematic diagram of the surface coating structure in Embodiment 2 of the present invention, which includes an inner surface coating and an outer surface coating.

[0026] Figure 9 This is a schematic diagram of the structure of the support member inside the first spacer film-coated part in another embodiment of the present invention;

[0027] Figure 10This is a schematic diagram of the bare support structure in Embodiment 3 of the present invention, including a first support portion and a second support portion;

[0028] Figure 10a This is a schematic diagram of the structure in Embodiment 3 of the present invention, in which the first support portion and the second support portion have different radial thicknesses;

[0029] Figure 11 This is a schematic diagram of the structure of two bare stents covered with stents in a straight blood vessel segment when they are attached to form a complete circle in Embodiment 3 of the present invention;

[0030] Figure 12 These are schematic diagrams of the balloon dilation system in Embodiments 4 and 5 of the present invention;

[0031] Figure 12a This is a schematic diagram of the protrusion height structure of the first protrusion and the second protrusion in Embodiment 5 of the present invention;

[0032] Figure 13 This is a schematic diagram of the internal cross-sectional structure of the balloon catheter in Embodiment Six of the present invention;

[0033] Figure 14 This is a partial cross-sectional structural diagram of the anti-slip component in Embodiment 6 of the present invention, when the second protrusion is included;

[0034] Figure 15 This is a schematic diagram of the structure in Embodiment 6 of the present invention, in which the constraint member and the intermediate member are set independently and the intermediate member is set in parallel with the constraint member;

[0035] Figure 16 This is a schematic diagram of a straight-extending intermediate component structure in one embodiment of the present invention (Sixth Embodiment).

[0036] Figure 17 This is a schematic diagram of the spiral extension structure of the intermediate component in one embodiment of the present invention (Sixth Embodiment).

[0037] Figure 18 This is a schematic diagram of the fixing ring and retaining ring configuration in Embodiment Six of the present invention;

[0038] Figure 19 This is a schematic diagram of the deformed part of the balloon substrate with a semi-circular radial cross section near the proximal end of the support mounting part in Embodiment 7 of the present invention;

[0039] Figure 20 This is a schematic diagram of the radial cross-sectional structure of the deformed part in Embodiment 7 of the present invention. Detailed Implementation

[0040] To better understand the concept of this application, the implementation methods of this application will be described in detail below with reference to the accompanying drawings. The following specific embodiments are only some embodiments of this application and are not intended to limit this application.

[0041] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0042] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0043] To more clearly describe the structure of this application, the terms "proximal" and "distal" are used here as conventional terms in the field of interventional medicine. Specifically, "proximal" refers to the end of the blood vessel closer to the heart, and "distal" refers to the end of the blood vessel farther from the heart; "axial" refers to its length direction, and "radial" refers to the direction perpendicular to the "axial" direction; "upper end" and "lower end" are two relatively distant ends, and when one end is defined as "upper end", the other distant end is "lower end".

[0044] Example 1:

[0045] Please see Figures 1-3 This application provides a balloon dilation system 100, including a covered stent 10 and a balloon catheter 50 for delivery thereto. The covered stent 10 is delivered to the site of a vascular lesion through the balloon catheter 50 and is released within the blood vessel through dilation of the balloon catheter 50. (See also...) Figure 3The covered stent 10 is a tubular structure with openings at both ends. The covered stent 10 includes a main stent 1, the surface of which is covered with a surface coating 2. The main stent 1 supports the surface coating 2, and the surface coating 2 isolates blood. The main stent 1 includes multiple support skeletons 11, which are spaced apart along the axial direction of the covered stent 10. Adjacent support skeletons 11 are connected by the surface coating 2. The surface coating 2 is a flexible covering material, which can be formed by covering and connecting multiple support skeletons 11 using spinning, dip coating, or a polymer film to create a single unit. In this embodiment... Multiple support skeletons 11 can be covered and connected using PTFE membrane. In this embodiment, the covered stent 10 also includes a bare stent 3. The proximal side of the main stent 1 includes a connecting stent 12. The bare stent 3 is connected to the connecting stent 12 via a connecting rod 4. Here, the covered stent 10 provided in this application may need to be implanted into a bifurcation vessel 30. When the covered stent 10 is implanted at this location, the straight vessel segment 20 before the bifurcation needs to be extended upwards by a certain distance to place stents on both sides in a kissing pattern, so as to obtain a certain anchoring area in the straight vessel segment 20 region and prevent stent displacement. It should be understood that, please refer to Figure 1a When two fully covered stents are placed parallel to each other in the lumen of the straight vessel segment 20, a residual closed lumen 40 will be created. This residual closed lumen 40 not only occupies the space in the lumen, but also easily leads to the risk of thrombosis and re-embolization.

[0046] Therefore, the bare stent 3 of the covered stent 10 in this application can be placed in the region of the straight vessel segment 20 to form an anchoring area. The main stent 1 with the surface covering 2 is placed flush with the bifurcation. In this way, after the vascular stents are placed on both sides, the bare stent 3 of the two covered stents 10 are not covered, which can effectively avoid the formation of the closed residual lumen 40 and greatly reduce the surgical risk. Furthermore, in this embodiment, when the bare stent 3 is subjected to radial pressure, at least one side in the circumferential direction can deform. When the bare stent 3 of the two covered stents 10 are parallel in the straight vessel segment 20, the deformable side is close to each other, thereby forming two bare stent 3 shapes with a near semi-circular shape. When they are combined, they form a circle similar to the lumen contour of the straight vessel segment 20, thereby enhancing the anchoring force and better adapting to the shape of the vessel body 51, ensuring the patency of blood flow and minimizing the formation of thrombi.

[0047] In this embodiment, please refer to Figure 4Both the supporting frame 11 and the bare bracket 3 include a plurality of hexagonal grids 111 continuously arranged circumferentially. Each hexagonal grid 111 includes at least one pair of symmetrically arranged connecting sides 1111 circumferentially. Two adjacent hexagonal grids 111 are connected by these connecting sides 1111. The hexagonal grid 111 can be a regular hexagon, an equilateral but not equal-angle hexagon, or a hexagon with both equal sides and angles. When subjected to external pressure, the hexagonal grid 111 structure can evenly distribute the force to the six adjacent faces, reducing local stress concentration and thus enhancing the overall compressive strength. When the covered stent 10 is configured as a balloon dilatation stent, the support frame 11 with hexagonal grid 111 can provide good support performance after the stent is deployed, while avoiding local stress concentration, thereby ensuring the stability of the long-term shape of the covered stent 10. The connection by symmetrical connecting sides 1111 can make the stability of adjacent hexagonal grids 111 stronger. At the same time, the connecting sides 1111 with axial length can provide better axial support force, and when the hexagonal grid 111 is expanded by the balloon expansion force, it can prevent the connection position of adjacent hexagonal grids 111 from breaking during the expansion process.

[0048] In one embodiment, please refer to Figure 6 and Figure 7 The two ends of the connecting side 1111 in the axial direction are the bending positions when the hexagonal grid 111 expands. The stress is relatively large when bending. In order to disperse the stress concentration at this position, the two connecting sides 1111 can be connected by at least two support rods 1115. The two support rods 1115 and the two connecting sides 1111 enclose a transition grid 1116. The setting of the support rods 1115 can disperse the stress of both the connecting side 1111 and the support rods 1115 when bending at this position, thereby avoiding excessive stress concentration and bending fracture.

[0049] In another embodiment, the transition grid 1116 can serve as an optional location for the developing element in the coating support 10. By embedding the developing element within the transition grid 1116, the overall volume of the support can be increased, which would affect the compression and release of the support if it were placed in other locations. The developing element can be a material with developing effect, such as gold, platinum, tantalum, or barium sulfate.

[0050] In this embodiment, please refer again. Figure 4 and Figure 5Adjacent hexagonal grids 111 are connected by two symmetrical connecting sides 1111, forming two symmetrically arranged triangular waves 1112 at both ends of the axial direction. Each triangular wave 1112 includes wave rods 1113 located on both sides and connected to the connecting sides 1111, and a shoulder 1114 connecting the two wave rods 1113. The triangular waves 1112 achieve angle changes through the circumferential swing of the wave rods 1113 and the bending at the shoulder 1114, thereby expanding and contracting the hexagonal grids 111. The shoulder 1114 includes an arc apex 11141 and a transition rod 11142 connecting the arc apex 11141 and the two wave rods 1113. It should be understood that when the arc apex 11141, transition rod 11142, and wave rods 1113 of the shoulder 1114 are of equal width or equal diameter, the shoulder 1114... When bending occurs, stress is usually concentrated at the apex 11141. Excessive stress concentration at the apex 11141 can easily lead to fracture. Therefore, in this embodiment, in order to disperse the stress concentration at the apex 11141, the circumferential width L2 of the apex 11141 and the circumferential width L0 of the wave rod 1113 are made greater than the circumferential width L1 of the transition rod 11142, thus forming a teardrop-shaped transition structure. When bending occurs at the shoulder 1114, the transition rod 11142 with a smaller width L1 is more likely to bend the apex 11141 and the wave rod 1113 with a larger width, thereby dispersing some of the stress originally concentrated at the apex 11141 to the transition rods 11142 on both sides, achieving stress dispersion, thereby reducing the possibility of fatigue at the apex 11141 and improving the fatigue resistance of the support frame 11 within the body.

[0051] Furthermore, in one embodiment, the circumferential width L2 of the arc apex 11141 is greater than the circumferential width L0 of the wave rod 1113. Thus, the width L2 of the arc apex 11141 is greater than the widths of the transition rods 11142 and the wave rods 1113 on both sides. When bending, the deformation is better than occurring at the position with a lower width. Therefore, the bending stress of the arc apex 11141 can be distributed to the transition rods 11142 and the wave rods 1113 on both sides, thereby avoiding breakage at the bending point of the arc apex 11141.

[0052] In this embodiment, the support frame 11, connecting rod 4 and bare bracket 3 can be made of metal materials such as stainless steel, cobalt-chromium alloy, nickel-titanium alloy, and platinum-iridium alloy, or they can be non-metallic materials. Specifically, in this embodiment, cobalt-chromium alloy is selected as the material for forming the support frame 11, connecting rod 4 and bare bracket 3.

[0053] Example 2:

[0054] In this embodiment, please refer to Figure 8 Hungry Figure 9The structure of the main stent 1 and bare stent 3 of the covered stent 10 is generally the same as that in Embodiment 1. The difference is that the surface covering 2 includes an inner surface covering 24 and an outer surface covering 23. The inner surface covering 24 is applied to the inner surface of the main stent 1, and the outer surface covering 23 is applied to the outer surface of the main stent 1. The inner surface covering 24 and the outer surface covering 23 form a first spacer covering portion 21 between two adjacent support skeletons 11. The double-layer surface covering 2 can completely wrap the multiple support skeletons 11 of the main stent 1 implanted in the bifurcation vessel 30 within the covering, thereby avoiding the metal support skeletons 11 from directly contacting the vessel wall and causing unnecessary stimulation to the vessel. At the same time, the inner surface covering 24 on the inner surface can improve the long-term patency of blood flow in the stent and reduce the probability of thrombosis. The formation of the first spacer film portion 21 creates a gap between the axially adjacent support frames 11, thereby providing better bending performance. Since the first spacer film portion 21 is unsupported, the double-layer film formed by the first spacer film portion 21 can provide a certain degree of support and connection.

[0055] In another embodiment, please refer to Figure 9 Because the supporting frame 11 consists of a flexible first spacer membrane portion 21, the membrane-covered bracket 10 is prone to collapse within the first spacer membrane portion 21, leading to severe deformation of the lumen. This causes the lumen to shrink at that location, resulting in a discontinuous and uneven lumen shape along the axial direction of the membrane-covered bracket 10. Therefore, in this embodiment, the membrane-covered bracket 10 includes a support member 5, which is embedded within the first spacer membrane portion 21 and is continuously or intermittently arranged along the circumferential direction. There is no rigid connection between the support member 5 and the supporting frame 11. The lumen shape of the first spacer membrane portion 21 is kept consistent with the position of the supporting frame 11 solely through the supporting performance of the support member 5 itself, thereby reducing or preventing collapse. Furthermore, the radial support force of the support member 5 is greater than that of the first spacer film-covered portion 21. Here, the support member 5 can be configured as a multi-strand support ring, which is independent of the support frame 11 and has no axial rigidity or low axial rigidity. The support member 5 is disposed within the first spacer film-covered portion 21 and can vary with the circumferential diameter of the film-covered bracket 10. It is not connected to the support frame 11 and plays a circumferential support role. In this embodiment, the radial support force of the support member 5 can be at least 1.3 to 1.5 times that of the first spacer film-covered portion 21 to ensure that the support can maintain the shape of the flexible package and avoid collapse. The support member 5 can be a ring-shaped wave structure made of woven metal wire or cut metal tubing, or it can be a ring-shaped support structure molded from polymer material.

[0056] Example 3:

[0057] In this embodiment, please refer to Figures 10-11The structure of the main stent 1 and the surface covering 2 of the covered stent 10 is largely the same as in Embodiment 1. The difference lies in that, in order to improve the mutual anchoring and adhesion between the two bare stents 3 at their proximal ends when the two covered stents 10 are implanted at the two bifurcated vessels 30, the bare stents 3 can include a first support portion 31 and a second support portion 32 in the circumferential direction. The radial support force of the first support portion 31 is greater than that of the second support portion 32. Furthermore, see [reference needed]. Figure 11 When the covered stent 10 is implanted into the bifurcation vessel 30 and the bare stent 3 is located in the straight vessel segment 20 region, the first support portion 31 is attached to one side of the vessel wall, and the second support portion 32 is away from the vessel wall and is used to abut and anchor with the second support portion 32 of the other covered stent 10. Here, since the second support portion 32 has a lower radial support force, it is easy to deform. Therefore, when it comes into contact with and is squeezed by the second support portion 32 of the other covered stent 10, it can be deformed into a flat edge shape that is close to a semicircle, thereby forming a semicircular structure with the first support portion 31. The first support portion 31 and the second support portion 32 of the bare stent 3 of the other covered stent 10 also form a semicircular structure. A complete circular structure is formed between the two bare stents 3, which better fits the lumen shape of the straight vessel segment 20 region, thereby avoiding the formation of the closed residual lumen 40, greatly reducing the surgical risk, and providing better vascular support performance for the straight vessel segment 20 region. Here, in order to better compress the bare stent 3 with the other covered stent 10 after implantation into the blood vessel to form a semi-circular structure, the first support portion 31 and the second support portion 32 each occupy half of the circumference of the bare stent 3. In this way, while the second support portion 32 is compressed, the arc length occupied by the first support portion 31 is semi-circular, thus forming a semi-circular structure.

[0058] In this embodiment, please refer to Figure 10aTo reduce the radial support force of the second support portion 32 to that of the first support portion 31, under the condition that other factors remain unchanged (meaning the materials, lumen diameter, and mesh shape of the first and second support portions remain unchanged), the radial thickness D1 of the metal skeleton of the second support portion 32 can be reduced to the radial thickness D2 of the metal skeleton of the first support portion 31, or the circumferential thickness of the metal skeleton of the second support portion 32 can be reduced to the circumferential thickness of the metal skeleton of the first support portion 31, or the axial thickness of the metal skeleton of the second support portion 32 can be reduced to the axial thickness of the metal skeleton of the first support portion 31. Alternatively, the thickness of the metal skeleton of the second support portion 32 in multiple directions can be reduced to the thickness of the metal skeleton of the first support portion 31 in multiple directions. Alternatively, the coverage density of the bare support 3 on the metal skeleton of the second support portion 32 can be reduced to be less than that on the metal skeleton of the first support portion 31. Reducing the thickness of the metal skeleton reduces its stiffness, thereby reducing the support force, while reducing the coverage density of the metal skeleton can reduce the support force by reducing the number of support positions.

[0059] In the embodiment, the magnitude of the radial support force of the first support portion 31 and the second support portion 32 of the bare bracket 3 can be characterized by fixing one of the first support portion 31 and the second support portion 32, and then measuring the force applied to both portions when the same deformation is applied to the other portion. For example, first fix the shape of the first support portion 31, and then apply radial pressure to the second support portion 32 on the other side using a flat plate force gauge to one-third of its deformation radius, and read the first force value used for deformation. Then fix the shape of the second support portion 32, and then apply radial pressure to the first support portion 31 on the other side using a flat plate force gauge to one-third of its deformation radius, and read the second force value used for deformation. At this time, the reading of the second force value is greater than the reading of the first force value.

[0060] Example 4:

[0061] In this embodiment, please refer to Figure 12This application also provides a balloon dilation system 100 including a covered stent 10 as described in Embodiments 1 to 3. In this embodiment, the structure of the main stent 1 and the surface covering 2 of the covered stent 10 is largely the same as in Embodiments 1 to 3. The balloon dilation system 100 also includes a balloon catheter 50, which includes a tube body 51, a balloon base 52, and an anti-slip component 53. The balloon base 52 is fixed to the distal end of the tube body 51, and the inner lumen of the balloon base 52 communicates with the inner lumen of the tube body 51. Here, the tube body 51 can be a double-lumen tube, one lumen for conveying the guidewire and the other lumen for connecting a balloon infusion device to inflate the balloon base 52. The balloon base 52 is used to load and transport the covered stent 10 to the target location of the human blood vessel, and to dilate and release the covered stent 10 upon reaching the target location. In this embodiment, to better prevent the covered stent 10 from slipping off the surface of the balloon catheter 50 when it is installed on the surface of the balloon base 52, the balloon base 52 is provided with an anti-slip component 53. The anti-slip component 53 covers the outer surface of the balloon base 52 and includes a plurality of first protrusions 531 protruding away from the balloon base 52. The plurality of first protrusions 531 are opposite to the first spacer covered portion 21 and at least restrict the axial slippage of the support frame 11. Here, the first protrusions 531 form a protrusion limiting structure on the surface of the balloon base 52, and regardless of whether the balloon is in a folded or inflated state, the first protrusions 531 can form a protrusion limiting structure compared to other positions on the balloon base 52. Therefore, regardless of whether the balloon matrix 52 is in an expanded or contracted state, it can form an axial limiting structure for the covered stent 10. Here, the first spacer covered portion 21 of the covered stent 10 is located between two adjacent support frames 11. The support frame 11 has a larger thickness than the covering portion 21. Therefore, when the covered stent 10 is attached to the surface of the balloon matrix 52, the two adjacent support frames 11 at the position of the first spacer covered portion 21 support a recess. At this time, a plurality of first protrusions 531 extend into the recess formed by the first spacer covered portion 21. When the two adjacent support frames 11 are subjected to axial force, the first protrusions 531 abut against and restrict the ends of the support frames 11, thereby forming an axial limiting structure.

[0062] In this embodiment, please continue to refer to Figure 12In order to ensure that the first protrusion 531 can be opposite to the first spaced film portion 21 and to prevent the first protrusion 531 from losing its axial limiting function when it is opposite to the support frame 11, specifically, a plurality of first protrusions 531 are arranged at intervals along the axial direction of the anti-slip component 53. The axial spacing arrangement is the same as the spacing arrangement of the support frame 11 of the film bracket 10. Furthermore, the axial spacing L3 between two axially adjacent first protrusions 531 is greater than the axial length L4 of the support frame 11 between the two first protrusions 531, and less than the sum of the axial spacing L5 between the two first spaced film portions 21 and the axial length L4 of the support frame 11 between the two first protrusions 531. The axial spacing L5 between the two first spaced film portions 21 refers to twice the average value of the axial spacing of the first spaced film portions 21 where the two first protrusions 531 are located. Here, setting the length to be greater than the axial length of the support frame 11 allows two axially adjacent first protrusions 531 to span at least one support frame 11, thereby restricting the axial sliding of at least one support frame 11. The axial interval length between two axially adjacent first protrusions 531 is less than the sum of the axial interval length of the two first protrusions and the axial length of the support frame 11. This is also to avoid the axial interval length between two adjacent first protrusions 531 being too long, causing one of the first protrusions 531 to be opposite the support frame 11 and unable to play an axial limiting role. The first protrusion 531 loses its restriction on the sliding of the support frame 11 in one axial direction and fails.

[0063] Example 5:

[0064] In this embodiment, please continue to refer to Figure 12 and Figure 12aThe balloon catheter 50 and the covered stent 10 of the provided balloon dilation system 100 are largely the same as those in Embodiments 1 to 4. The difference is that, as shown in the figure, the outward expansion force generated by the expansion of the balloon base 52 causes the covered stent 10 to expand accordingly. During this process, when the balloon base 52 expands from a ring-shaped winged state, the winged part will gradually unfold outward. This process is usually uneven. When there is a large and uneven shear force between the covered stent 10 and the anti-slip component 53, this uneven force will be gradually transferred to the covered stent 10, resulting in uneven expansion of the covered stent 10. Therefore, in this embodiment, the anti-slip component 53 includes a contact portion 533 other than the first protrusion 531. The radial thickness H1 of the contact portion 533 is less than the radial thickness H2 of the first protrusion 531, and the surface roughness of the contact portion 533 is less than or equal to the surface roughness of the first protrusion 531. Here, since the first protrusion 531 is opposite to the first spaced film-coated portion 21 of the film-coated bracket 10, the support frame 11 portion and the bare bracket 3 portion of the film-coated bracket 10 are opposite to the contact portion 533. The radial thickness H1 of the contact portion 533 is... Maintaining a thickness lower than that of the first protrusion 531 ensures the axial limiting effect of the first protrusion 531 on the supporting frame 11. Making the surface roughness of the contact portion 533 less than that of the first protrusion 531 allows the anti-slip component 53 to maintain a low coefficient of friction with the covered stent 10, enabling the balloon base 52 to generate a large circumferential slip on the inner surface of the covered stent 10, reducing the shear force between them, and promoting relative circumferential movement between the covered stent 10 and the balloon base 52, thereby mitigating the uneven expansion of the covered stent 10.

[0065] In one embodiment, not shown in the figure, to reduce the surface roughness of the contact portion 533, a smooth, low-friction material coating, such as a PTFE coating material or an FEP coating material, can be attached to the contact portion 533 of the anti-slip component 53.

[0066] In another embodiment, please continue to refer to Figure 12aTo further prevent uneven expansion of the balloon matrix 52 from affecting the expansion of the covered stent 10, this can be achieved by reducing the contact area between the covered stent 10 and the anti-slip component 53. Specifically, the anti-slip component 53 includes multiple second protrusions 532, which are located on the contact portion 533 and protrude from the outer surface of the contact portion 533. The radial thickness H3 of the second protrusion 532 is less than the radial thickness H2 of the first protrusion 531. The second protrusions 532 are provided on the surface of the contact portion 533, and the second protrusions 532 support the part of the support frame 11 that is in contact with the contact portion 533. The support frame 11 and the first protrusion 532 are connected to the first protrusion 531. The contact point between the two protrusions 532 is lifted by the second protrusion 532, while the other positions not in contact with the second protrusion 532 are suspended. When not in contact, the surface roughness is zero, and there is no friction. Therefore, the circumferential traction of the covered stent 10 during the expansion of the balloon base 52 only includes the position where the second protrusion 532 contacts the support frame 11. Thus, when the covered stent 10 expands with the balloon base 52, the axial displacement is limited by the first protrusion 531, while the circumferential slippage is reduced due to the decrease in surface roughness and the reduction in contact points, achieving a relatively uniform expansion effect for the covered stent 10. In this embodiment, because the radial thickness H3 of the second protrusion 532 is less than the radial thickness H2 of the first protrusion 531, after the support frame 11 of the covered stent 10 is attached to the second protrusion 532, the first protrusion 531 can still extend into the first spaced covered portion 21 to form an axially restrictive structure on the support frame 11.

[0067] In this embodiment, please refer to Figure 12a The balloon base 52 includes a support mounting portion 521 located between its two axial ends. The support mounting portion 521 is used for mounting the covered stent 10. The two axial ends are used to fix and seal with the catheter, forming a sealed inner cavity of the balloon base 52. The support mounting portion 521 typically has a relatively straight tubular mounting structure after expansion, while the two axial ends typically have a tapered structure. The anti-slip component 53 can completely cover the outer surface of the balloon base 52 or only partially cover the support mounting portion 521, such that the first protrusion 531 and the second protrusion 532, as well as the contact portion 533, are located at least on the support mounting portion 521 for cooperating with the covered stent 10.

[0068] Example 6:

[0069] In this embodiment, please refer to Figure 13 and Figure 14The balloon catheter 50 and the covered stent 10 of the provided balloon dilation system 100 are largely the same as those in Embodiments 1 to 5. The difference is that the anti-slip component 53 includes an outer cover layer 5301, an inner cover layer 5302, a restraint member 5311, and an intermediate member 5321. The inner cover layer 5302 is a thin-walled structural component made of a flexible material. Its cross-sectional shape is consistent with that of the balloon substrate 52. It has a certain elasticity in the circumferential direction and cannot be stretched in the axial direction. This allows it to fit well with the balloon substrate 52 without creating gaps. The inner covering layer 5302 is attached to the outer surface of the balloon base 52. It is a flexible material that can change shape with the balloon base 52 without affecting its form. The restraint member 5311 rests on its surface. The outer covering layer 5301 covers the outer surface of the inner covering layer 5302, its function being to cover and restrain the restraint member 5311, preventing it from slipping or falling off. The restraint member 5311 is positioned between the outer covering layer 5301 and the inner covering layer 5302 to secure the outer covering layer. A first protrusion 531 is formed on the surface of 5301, and an intermediate member 5321 is disposed between the outer cover layer 5301 and the inner cover layer 5302 to form a second protrusion 532 on the surface of the outer cover layer 5301. Here, the diameter or radial thickness of the intermediate member 5321 should be smaller than the diameter or radial thickness of the constraint member 5311, so that when the first protrusion 531 and the second protrusion 532 are formed, the first protrusion 531 has a larger radial thickness than the second protrusion 532.

[0070] In this embodiment, please refer to Figure 15 and Figure 16 The constraint member 5311 and the intermediate member 5321 can be independently configured. Specifically, the constraint member 5311 can be configured as a circumferentially continuous constraint ring at a position opposite to the first spaced film portion 21, with multiple constraint rings spaced axially, having the same structural configuration as the first protrusion 531 when forming it. Alternatively, the constraint member 5311 can be configured as multiple constraint members 5311 spaced circumferentially at a position opposite to the first spaced film portion 21. The intermediate member 5321 can be formed as a second protrusion 532 at a position opposite to the contact portion 533 between the inner surface cover and the outer surface film 23. The intermediate member 5321 can be multiple protrusions distributed along the axial and circumferential directions of the contact portion 533; it can also be a support strip extending axially, with multiple support strips spaced circumferentially. It can also be an intermediate ring arranged parallel to the constraint ring, with multiple intermediate rings spaced axially; or it can be a spiral rod embedded in the contact portion 533, wound in the axial direction.

[0071] In one embodiment, see Figure 17The constraint 5311 and the intermediate 5321 are integrally formed. Here, the constraint 5311 and the intermediate 5321 can be formed by a single filament. The single filament has a different filament diameter distribution. After being wrapped around the balloon base 52 in the circumferential direction at the position opposite to the first spacer membrane 21, it extends axially in a spiral or straight direction to the next adjacent first spacer membrane 21 position and continues to be wrapped around the balloon base 52 in the circumferential direction until all the positions opposite to the first spacer membrane 21 of the membrane support 10 are completed. Here, when the single filament is wound, the filament diameter of the single filament with a different filament diameter distribution at the position opposite to the first spacer membrane 21 should be greater than the filament diameter at other positions.

[0072] In this embodiment, please refer to Figure 18 The outer cover layer 5301 and the inner cover layer 5302 can be connected by adhesive bonding or by vacuum adsorption. When using vacuum adsorption, the two ends of the outer cover layer 5301 and the inner cover layer 5302 are sealed and fixed to the two ends of the balloon base 52 by fixing rings 54. Specifically, the fixing rings 54 are at least partially directly connected and sealed to the tube body 51, while the other part presses against the ends of the outer cover layer 5301, the inner cover layer 5302 and the balloon base 52 and is connected and sealed to the outer cover layer 5301. Here, the anti-slip component 53 formed by the outer cover layer 5301 and the inner cover layer 5302 can be applied to the surface of the balloon base 52 by electrostatic adsorption. This anti-slip component 53 can achieve adhesion while reducing the pull of the balloon base 52 on it during expansion.

[0073] In another embodiment, please refer to Figure 18 A retaining ring 55 can be provided inside the fixing ring 54. Before the fixing ring 54 fixes the ends of the outer covering layer 5301, inner covering layer 5302, and balloon base 52 to the tube body 51, the retaining ring 55 clamps the ends of these components. Then, the fixing ring 54 simultaneously presses the ends of the outer covering layer 5301, inner covering layer 5302, and balloon base 52, along with the retaining ring 55 clamped thereon. In this way, the retaining ring 55 further enhances the sealing effect of the outer covering layer 5301 and inner covering layer 5302, while also providing good axial fixation and limiting, preventing slippage of the outer covering layer 5301 and inner covering layer 5302. The retaining ring 55 can be located on the outer covering layer 5301, between the outer covering layer 5301 and inner covering layer 5302, or between the balloon base 52 and inner covering layer 5302. The retaining ring 55 has a ring-shaped structure, and its radial cross-section can be circular or polygonal. The retaining ring 55 can be made of metal materials, such as stainless steel, nickel-titanium materials, cobalt-chromium alloy materials, titanium alloys, tantalum metal, platinum-iridium alloys, gold, etc., or it can be made of polymer materials, such as ABS, PC, FEP, PTFE, etc.

[0074] Example 7:

[0075] In this embodiment, please refer to Figure 19 and Figure 20 The balloon catheter 50 and covered stent 10 of the provided balloon dilation system 100 are largely the same as those in Embodiments 1 to 6. The difference is that, as mentioned in the aforementioned embodiments, the bare stent 3 of the covered stent 10 provided in this application can be placed in the region of the straight blood vessel segment 20 to form an anchoring area, and the main stent 1 with the surface covering 2 is placed flush with the bifurcation. In this way, after the vascular stents are placed on both sides, the bare stent 3 of the two covered stents 10 are not covered, which can effectively avoid the formation of the closed residual cavity 40 and greatly reduce the surgical risk. Furthermore, the bare stent 3 includes a first support portion 31 and a second support portion 32 in the circumferential direction. The radial support force of the first support portion 31 is greater than that of the second support portion 32. The second support portion 32 has a lower radial support force and is more prone to deformation. Therefore, when it comes into contact with and is compressed by the second support portion 32 of another covered stent 10, it can be deformed into a nearly semi-circular straight edge shape, thereby forming a semi-circular structure with the first support portion 31. The first support portion 31 and the second support portion 32 of the bare stent 3 of the other covered stent 10 also form a semi-circular structure. The two bare stents 3 form a complete circular structure, which better fits the lumen shape of the straight vessel segment 20 region, thereby avoiding the formation of the closed residual lumen 40, greatly reducing the surgical risk, and providing better vascular support performance for the straight vessel segment 20 region. Therefore, in order for the balloon catheter 50 provided in this application to better adapt to the structure of the covered stent 10 after release in the blood, the balloon base 52 includes a stent mounting portion 521, which is located between the two ends of the balloon base 52 in the axial direction. The proximal side of the stent mounting portion 521 includes a deformable portion 5211. When the balloon base 52 is in the expanded state, any radial section of the deformable portion 5211 is a semi-circular section. Here, when the covered stent 10 is compressed onto the balloon catheter 50, it should adhere to the compressed balloon base 52. When the balloon base 52 expands, the covered stent 10 expands along with the balloon base 52. Therefore, the basic shape of the balloon matrix 52 after expansion can basically determine the basic shape of the covered stent 10 after expansion. A deformable part 5211 with a semi-circular radial cross section is provided on one side of the stent mounting part 521. When the covered stent 10 is installed, the bare stent 3 is installed at the position of the deformable part 5211, and the first support part 31 is attached to the semi-circular arc side of the semi-circular radial cross section, and the second support part 32 is attached to the side of the semi-circular radial cross section away from the semi-circular arc. In this way, the bare stent 3 expands with the expansion of the deformable part 5211, and at the same time, in accordance with the semi-circular structure after the expansion of the deformable part 5211, the bare stent 3 also has a semi-circular structure.

[0076] Here, it can be understood that the deformable part 5211 is used to guide the bare stent 3 to form a semi-circular structure during expansion. Even if the bare stent 3 does not form a semi-circular structure as expected, the second support part 32 is the part that contacts and compresses the bare stent 3 of the covered stent 10 on the other side. The second support part 32 has a low radial support force and is easy to deform. Therefore, under mutual compression, the proximal bare stents 3 of the two covered stents 10 located in the two branch vessels can form two semi-circular bare stents 3 in the region of the straight vessel segment 20 where the two bifurcated vessels 30 intersect, thereby forming a complete circle with a lumen shape similar to that of the straight vessel segment 20 region. This effectively avoids the formation of the closed lumen 40 and greatly reduces the surgical risk.

[0077] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A covered stent, characterized in that, The coated support is a tubular structure with openings at both ends. The coated support includes a main support, and the surface of the main support is coated with a surface film. The main support includes multiple support skeletons, which are spaced apart along the axial direction of the coated support. A first spaced coated portion is formed between two adjacent support skeletons, and the two adjacent support skeletons are connected through the first spaced coated portion.

2. The covered stent according to claim 1, characterized in that, The proximal side of the main support includes a bare support, which includes a first support portion and a second support portion in the circumferential direction. The radial support force of the first support portion is greater than that of the second support portion.

3. A balloon dilation system, characterized in that, The device includes a covered stent and balloon catheter as described in claim 1 or 2. The balloon catheter includes a tube body, a balloon base, and an anti-slip component. The balloon base is fixed to the distal end of the tube body, and the inner lumen of the balloon base communicates with the inner lumen of the tube body. The anti-slip component is applied to the outer surface of the balloon base and includes a plurality of first protrusions that protrude away from the balloon base. The plurality of first protrusions are opposite to the first spaced covered portion and at least restrict the axial slippage of the support frame.

4. The balloon dilation system according to claim 3, characterized in that, Multiple first protrusions are spaced apart along the axial direction of the anti-slip component. The axial distance between two axially adjacent first protrusions is greater than the axial length of the support frame, but less than the sum of the axial distance between the two first protrusions and the axial length of the support frame between the two first protrusions.

5. The balloon dilation system according to claim 3, characterized in that, The anti-slip component includes a contact portion other than the first protrusion, the radial thickness of the contact portion is less than the radial thickness of the first protrusion, and the surface roughness of the contact portion is less than the surface roughness of the first protrusion.

6. The balloon dilation system according to claim 5, characterized in that, The anti-slip component includes a plurality of second protrusions, which are disposed on the contact portion and protrude from the outer surface of the contact portion. The radial thickness of the second protrusion is less than the radial thickness of the first protrusion.

7. The balloon dilation system according to claim 6, characterized in that, The anti-slip component includes an outer cover layer, an inner cover layer, a restraining member, and an intermediate member. The inner cover layer is attached to the outer surface of the balloon substrate, the outer cover layer is applied to the outer surface of the inner cover layer, the restraining member is disposed between the outer cover layer and the inner cover layer to form a first protrusion on the surface of the outer cover layer, and the intermediate member is disposed between the outer cover layer and the inner cover layer to form a second protrusion on the surface of the outer cover layer.

8. The balloon dilation system according to claim 7, characterized in that, The constraint component and the intermediate component are set independently, or the constraint component and the intermediate component are integrally formed.

9. The balloon dilation system according to claim 7, characterized in that, The anti-slip component includes two fixing rings. The outer cover layer and the inner cover layer are vacuum adsorbed, and the two ends of the outer cover layer and the inner cover layer are respectively sealed and fixed to the two ends of the balloon base through one of the fixing rings.

10. The balloon dilation system according to claim 7, characterized in that, The balloon matrix includes a support mounting portion located between the two ends of the balloon matrix in the axial direction. The proximal side of the support mounting portion includes a deformable portion. When the balloon matrix is ​​in an expanded state, any radial section of the deformable portion is a semi-circular section.

11. The balloon dilation system according to claim 10, characterized in that, When the coated bracket is installed on the bracket mounting part, the bare bracket is installed on the deformable part, and the first support part is located on the semi-circular arc side of the semi-circular cross section.

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