Short head bracket system

Abstract

The present disclosure provides a short-head stent system, comprising a delivery catheter, a delivery guide wire, a beaded braided tube and a vascular stent, wherein the proximal end of the beaded braided tube is connected to the distal end of the delivery guide wire, the beaded braided tube and the vascular stent are both tubular mesh structures woven from braided wires, the beaded braided tube is located in the vascular stent, the beaded braided tube and the vascular stent can both be located in the delivery catheter and be in a compressed state, and can both be released from the delivery catheter and expanded, wherein in the compressed state, the length of the distal end of the beaded braided tube extending beyond the distal end of the vascular stent is not greater than a first threshold value, and during the process of the vascular stent being released from the delivery catheter until the release is completed, the length of the distal end of the beaded braided tube extending beyond the distal end of the vascular stent is not greater than a second threshold value, wherein both the first threshold value and the second threshold value are not greater than 5 mm.

Description

Technical Field

[0001] The present disclosure relates to the technical field of medical devices, and in particular to a stent system. Background Art

[0002] Intravascular stent implantation therapy usually involves delivering the stent to the diseased blood vessel using a guide wire and a catheter, and then releasing the stent to achieve the purpose of treating the diseased blood vessel.

[0003] In existing vascular stent systems, the distal tip of the guide wire is mostly composed of a platinum coil, which is soft and has a certain degree of elasticity. During the operation, the guide wire is pushed discontinuously to unfold the stent, causing the stent to gradually expand and open. During this process, the guide wire tip will gradually extend toward the distal blood vessel. For distal blood vessels with thinner lumens and thinner walls, the guide wire tip can easily cause damage to the blood vessel wall. At the same time, because the guide wire tip is soft and elastic, during the pushing process, when the guide wire tip encounters an obstruction in the blood vessel and cannot be pushed forward smoothly, if the guide wire continues to be pushed, the guide wire tip may jump, which will cause great damage to the fragile blood vessels.

[0004] Moreover, during digital subtraction angiography (DSA) surgery, doctors will partially magnify the lesion area in order to obtain a clear field of view and better observe the treatment effect. In this case, the extension of the delivery guide wire may exceed the display range of the current DSA screen, making it impossible for doctors to accurately determine the position of the guide wire tip during the operation, which may cause unknown damage to the blood vessels.

[0005] In current stent systems, when the stent is in a compressed state, the delivery guide wire usually extends out of the stent by 10-15 mm. During the pushing process, the guide wire extends out of the stent even longer. Therefore, the above problem exists widely.

[0006] One solution is to place the distal end of the stent beyond the tip of the guidewire to create a headless stent system. However, since the stent is axially shortened when it is opened, in order to achieve a completely headless stent when it is opened, the distal end of the stent needs to be placed far beyond the tip of the delivery guidewire in a compressed state within the delivery catheter. This will cause the distal part of the stent that is not supported by the internal delivery guidewire to slightly collapse, and there is a risk of damage to the distal mesh of the stent, which will lead to poor distal wall adhesion after the stent is released, and there is a risk of ineffective stent treatment or thrombosis within the stent after stent implantation. Summary of the invention

[0007] In order to at least solve the above problems, the present disclosure provides a bracket system.

[0008] The stent system includes a delivery catheter, a delivery guide wire, a beaded braided tube and a vascular stent, wherein the proximal end of the beaded braided tube is connected to the distal end of the delivery guide wire, the beaded braided tube and the vascular stent are both tubular mesh structures woven from braided wires, the beaded braided tube is located in the vascular stent, the beaded braided tube and the vascular stent can both be located in the delivery catheter and be in a compressed state, and can both be released from the delivery catheter and expand, wherein in the compressed state, the length of the distal end of the beaded braided tube extending beyond the distal end of the vascular stent is not greater than a first threshold value, and during the process of the vascular stent being released from the delivery catheter until the release is completed, the length of the distal end of the beaded braided tube extending beyond the distal end of the vascular stent is not greater than a second threshold value, wherein both the first threshold value and the second threshold value are not greater than 5 mm.

[0009] In some optional embodiments, the first threshold is greater than the second threshold.

[0010] In some optional embodiments, the first threshold is equal to the second threshold.

[0011] In some optional embodiments, the first threshold is 5 mm, wherein the second threshold is 5 mm.

[0012] In some optional embodiments, assuming that the length of the beaded braided tube in the compressed state is A1, and the length after release is A2, the length of the vascular stent in the compressed state is B1, and the length after release is B2, and the length of the distal end of the braided tube extending out of the distal end of the vascular stent in the compressed state is A3, then:

[0013] When A3 = 5 mm, (A1-A2) ≥ (B1-B2);

[0014] When A3<5mm, (A1-A2)-(B1-B2)≥(A3-5mm).

[0015] In some optional embodiments, in the compressed state, the distal end of the beaded braided tube is substantially flush with the distal end of the vascular stent.

[0016] In some optional embodiments, during the process of releasing from the compressed state until the release is completed, the vascular stent has an axial length shortened to be less than or equal to the axial length shortened of the bead braided tube.

[0017] In some optional embodiments, the braided wire is made of a metal material; optionally, the metal material includes a memory metal; optionally, the memory metal includes one or more of a cobalt-chromium alloy, a platinum-tungsten alloy, and a nickel-titanium alloy.

[0018] In some optional embodiments, the beaded braided tube comprises at least one expandable segment, wherein the diameter of at least one of the expandable segments after natural expansion is larger than the inner diameter of the vascular stent after natural expansion; optionally, the beaded braided tube comprises: at least two expandable segments; and a contraction segment located between two adjacent expandable segments; optionally, the diameter of the most distal expandable segment after natural expansion is larger than the inner diameter of the vascular stent after natural expansion; optionally, the diameter of the most distal expandable segment after natural expansion is 1.1-2 times the inner diameter of the vascular stent after natural expansion; optionally, the diameters of the expandable segments after natural expansion are all larger than the inner diameter of the vascular stent after natural expansion; optionally, the most distal expandable segment is woven more densely than other expandable segments.

[0019] In some optional embodiments, the vascular stent is a self-expanding vascular stent, and the vascular stent includes: a stent body, which is woven into a tubular network structure by braiding wires, and the braiding wires include a first end, a second end opposite to the first end, and a portion between the first end and the second end; and a stent developing member, which is sleeved on the first end of the intersecting braided wires, and / or, is sleeved on the second end of the intersecting braided wires, wherein the first end and / or the second end has a first diameter, the portion between the first end and the second end has a second diameter, and the first diameter is smaller than the second diameter; optionally, the first diameter is less than or equal to half of the second diameter; optionally, at least two braided wires constitute a braiding group; the stent body is woven into a tubular network structure by the braiding group; optionally, the first end and / or the second end is connected to the developing member in a manner including gluing and / or or welding; optionally, a joint is formed at the connection between the first end and / or the second end and the developing member; optionally, the cross-sectional shape of the joint is any one of semicircular, semi-elliptical or semicircular; optionally, a transition chamfer is arranged between the braided wire and the first end and / or the second end; optionally, the angle α of the transition chamfer is in the range of 20°-90°; optionally, the angle α of the transition chamfer is in the range of 30°-60°; optionally, the length of the first end and / or the second end is L0, 0.3mm≤L0<10mm; optionally, the material of the braided wire includes metal material; optionally, the metal material is selected from one or more of titanium, nickel-titanium alloy, stainless steel, platinum-tungsten alloy, platinum, platinum-iridium alloy and cobalt-chromium alloy; optionally, the port at one or both ends of the bracket body is outwardly expanded; optionally, the port is in the shape of a trumpet.

[0020] The beneficial effects that can be achieved by the stent system provided by the present disclosure include but are not limited to the following aspects: in the short-head stent system provided by the present disclosure, whether in a compressed state or in the stent release process until the release is completed, the distal end of the beaded braided tube connected to the distal end of the delivery guide wire protrudes very little from the distal end of the stent, for example, not more than 5 mm, thereby solving the problem of the distal end of the guide wire of the traditional stent system causing damage to the distal blood vessel; and, in a compressed state, the distal end of the beaded braided tube can be no shorter than the distal end of the stent, thereby solving the problem of collapse of the distal end of the stent. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present disclosure will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings, which are for the purpose of illustrating specific embodiments only and are not to be considered as limiting the present invention.

[0022] Figure 1 It is a partial structural schematic diagram of the support system in a compressed state according to the first embodiment of the present disclosure.

[0023] Figures 2A-2D The principle of axial shortening is shown by way of example.

[0024] Figure 3 The axial shortening is shown by way of example when the braided wire is folded into different numbers of sections.

[0025] Figure 4 It is a partial structural schematic diagram of the support system in a compressed state according to the second embodiment of the present disclosure.

[0026] Figure 5 It is a schematic diagram showing that the distal end of the beaded braided tube does not extend out of the distal end of the vascular stent during the process of releasing the vascular stent.

[0027] Figure 6 It is a schematic diagram showing that the distal end of the beaded braided tube slightly extends out of the distal end of the vascular stent during the process of releasing the vascular stent.

[0028] Figure 7 It is a schematic diagram showing that the distal end of the beaded braided tube slightly protrudes from the distal end of the vascular stent after the vascular stent is completely released.

[0029] Figure 8 It is a partial structural schematic diagram of a beaded braided tube in a first state according to an embodiment of the present disclosure.

[0030] Fig. 9 is a schematic structural diagram of a beaded braided tube in a second state according to another embodiment of the present disclosure.

[0031] Fig.10 It is a schematic diagram of a vascular stent according to an embodiment of the present disclosure from a first perspective.

[0032] Fig.11 is a schematic diagram of a vascular stent according to an embodiment of the present disclosure from a second viewing angle.

[0033] Fig.12 3 is a schematic diagram of a vascular stent according to an embodiment of the present disclosure from a third viewing angle.

[0034] Fig.13 It is a schematic diagram of the structure of the braided wire of the vascular stent according to an embodiment of the present disclosure.

[0035] Fig.14 It is a schematic diagram of the cross-sectional structure of a developing ring according to an embodiment of the present disclosure.

[0036] Fig.15 is a schematic structural diagram of the first end of the braided wire according to an embodiment of the present disclosure.

[0037] Fig.16 It is a partial schematic diagram of a braiding group of a vascular stent according to an embodiment of the present disclosure.

[0038] Fig.17 The structure of the spring developing coil and the braided wire according to an embodiment of the present disclosure is shown in FIG. Figure 1 .

[0039] Fig.18 Schematic diagram of the cross-sectional structure of a spring developing coil and a braided wire according to an embodiment of the present disclosure Figure 1 .

[0040] Fig.19 is a schematic diagram of a vascular stent according to a second embodiment of the present disclosure from a first viewing angle.

[0041] Fig. 20 4 is a schematic diagram of a second viewing angle of a vascular stent according to a second embodiment of the present disclosure.

[0042] Fig.21 It is a schematic diagram of a vascular stent according to the second embodiment of the present disclosure from a third viewing angle.

[0043] Fig. 22 This is a second structural schematic diagram of a spring developing coil and a braided wire according to an embodiment of the present disclosure.

[0044] Fig.23 This is a second schematic diagram of the cross-sectional structure of a spring developing coil and a braided wire according to an embodiment of the present disclosure.

[0045] Fig.24 Schematic diagram of the cross-sectional structure of a spring developing coil and a braided wire according to an embodiment of the present disclosure Figure 3 .

[0046] Fig.25 Schematic diagram of the cross-sectional structure of a spring developing coil and a braided wire according to an embodiment of the present disclosure Figure 4 .

[0047] Fig.26 Schematic diagram of the cross-sectional structure of a spring developing coil and a braided wire according to an embodiment of the present disclosure Figure 5 .

[0048] Fig. 27 Schematic diagram of a developing wire of a spring developing coil according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0049] The present disclosure is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0050] In the description of the present disclosure, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicating directions or positional relationships, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0051] In the description of the present disclosure, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In the description of the present disclosure, it should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other.

[0053] The terms “distal end” and “proximal end” are used in the description of the present disclosure. The “proximal end” refers to the end close to the operator of the medical device; the “distal end” refers to the end far from the operator of the medical device.

[0054] As mentioned above, in a stent system, if the distal end of the delivery guidewire extends out of the stent for a long time, it may cause damage to the distal blood vessel. To achieve the goal that the distal end of the delivery guidewire does not extend out of the stent when the stent is opened, considering the axial shortening when the stent is opened, it is necessary to make the distal end of the stent longer than the distal end of the delivery guidewire in a compressed state, which in turn will cause the part of the distal end of the stent that is not supported by the internal delivery guidewire to slightly collapse. The so-called axial shortening when the stent is opened means that after the stent is released from the compressed state, it will expand in the radial direction and shorten in the axial direction.

[0055] In view of this, the present disclosure provides a stent system, which realizes that no matter in a compressed state or in the process of stent release until the release is completed, the distal end of the beaded braided tube connected to the distal end of the delivery guide wire protrudes very little from the distal end of the stent, for example, no more than 5 mm. In this way, the problem of the distal end of the beaded braided tube causing damage to the distal blood vessel can be solved. In addition, in a compressed state, the distal end of the beaded braided tube can be no shorter than the distal end of the stent. In this way, the problem of stent distal end collapse can be solved.

[0056] Figure 1 FIG. 1 is a partial structural schematic diagram of the stent system in a compressed state according to the first embodiment of the present disclosure. Figure 1 As shown, the stent system includes a delivery catheter 101 , a delivery guide wire 102 , a beaded braided tube 103 and a vascular stent 104 .

[0057] The beaded braided tube 103 includes at least one expandable section. The expandable section is a tubular mesh structure woven from braided wires, which can be placed in the delivery catheter 101 and is in a compressed state. Moreover, when the expandable section is partially or completely released from the delivery catheter 101, the expandable section can expand in the radial direction, and the beaded braided tube will also be axially shortened. The braided wires of the expandable section can be made of metal materials. The metal materials include memory metals and the like. For example, the memory metal can be cobalt-chromium alloy, platinum-tungsten alloy, nickel-titanium alloy, and the like.

[0058] The distal end of the beaded braided tube 103 can be a developing coil structure to ensure that the distal end of the entire stent system is visible under the fluoroscopic device, thereby helping to identify its position and movement direction in the blood vessel during interventional treatment. The proximal end of the beaded braided tube 103 is connected to the distal end of the delivery guide wire 102, and the beaded braided tube 103 can be pushed to the distal end or retracted to the proximal end by manipulating the delivery guide wire 102. The main body of the vascular stent 104 is a tubular mesh structure woven from braided wires. The beaded braided tube 103 is located in the vascular stent 104, and the beaded braided tube 103 and the vascular stent 104 are both located in the delivery catheter 101 and are in a compressed state. By pushing the delivery guide wire 102 to the distal end, the beaded braided tube 103 and the vascular stent 104 can be released and expanded from the delivery catheter 101.

[0059] exist Figure 1 In the illustrated embodiment, in the compressed state, the length of the distal end of the beaded braided tube 103 extending from the distal end of the vascular stent 104 is not greater than a first threshold. The first threshold is not greater than 5 mm, for example, 5 mm, 4 mm, etc. In other words, the distal end of the beaded braided tube 103 extends very little from the distal end of the vascular stent 104, thereby solving the problem of the distal end of the beaded braided tube damaging the distal blood vessel during the process of pushing the delivery catheter 101.

[0060] Meanwhile, during the entire process of releasing the vascular stent 104 from the delivery catheter 101 until the release is completed, the length of the distal end of the beaded braided tube 103 extending from the distal end of the vascular stent 104 is not greater than a second threshold. The second threshold is not greater than 5 mm, for example, it can be 5 mm, 4 mm, etc. In other words, the distal end of the beaded braided tube 103 extends very little from the distal end of the vascular stent 104, thereby solving the problem of the distal end of the beaded braided tube damaging the distal blood vessel during the process of releasing the vascular stent 104.

[0061] In order to meet the above requirements, considering that both the vascular stent and the beaded braided tube experience axial shortening during the release process, the axial shortening rates of the vascular stent and the beaded braided tube can be designed.

[0062] In order to clearly explain the design principle of the present invention, the following description is made by taking a single wire in the braided tube of a vascular stent and a beaded braided tube as an example. However, it should be noted that the tubular network structure of the vascular stent and the beaded braided tube is not limited to being woven from a single braided wire, but can also be woven from two or more braided wires.

[0063] Figures 2A-2D The principle of axial shortening is shown by way of example.

[0064] like Figure 2A As shown, it is assumed that the length of a single wire is 10, and the unit is not limited, it is only used to illustrate the principle.

[0065] like Figure 2B As shown, the single wire is in the delivery catheter and is in a compressed state. The single wire is folded into 10 sections, each section is 1 length. If the inner diameter of the delivery catheter is 0.5, then through simple geometric calculations, it can be seen that at this time, the angle between the two adjacent sections of the single wire is 120°, and the axial length of the single wire is about 8.7.

[0066] like Figure 2C As shown, after the single wire is completely released from the compressed state and is in an unconstrained state, the angle between two adjacent segments of the single wire can be set to 60°, for example, by heat setting treatment. At this time, the axial length of the single wire is 5.

[0067] like Figure 2DAs shown, after the single wire is completely released from the compressed state and is in an unconstrained state, the angle between two adjacent segments of the single wire can be set to 5°, for example, by heat setting treatment. At this time, the axial length of the single wire is about 0.44.

[0068] It can be seen from this that when a single wire is folded into the same number of sections, after being released from the compressed state, the smaller the angle between two adjacent sections of the single wire in the unconstrained state, the shorter its axial length, that is, the more it shortens, that is, the greater the axial shortening rate.

[0069] The axial shortening ratio was calculated as the ratio of the axial shortening length after release from the compressed state to the axial length in the compressed state.

[0070] The above discussion discusses folding the braided wire into the same number of segments. When designing, the braided wire can also be folded into different numbers of segments. Figure 3 The axial shortening is shown by way of example when the braided wire is folded into different numbers of sections.

[0071] like Figure 3 As shown, two braided wires with the same length of 10, if the radial height is limited to 0.87, and the angle between two adjacent segments is 60°, then they can be folded into 10 segments with an axial length of 5; if the radial height is limited to 0.71, and the angle between two adjacent segments is 39°, then they can be folded into 14 segments with an axial length of 3.36. Figure 3 In this example, the vascular stent can be made into a braided wire with a radial height of 0.87 in the unconstrained state, and the expandable section of the beaded braided tube can be made into a braided wire with a radial height of 0.71 in the unconstrained state. In the compressed state in the delivery catheter, the vascular stent and the beaded braided tube can be compressed to be equal in axial length or the beaded braided tube can be slightly longer than the vascular stent (because the two are equal in length in the straightened state), and then the two can be released and self-expanded into an unconstrained state, achieving Figure 3 At this time, since the axial shortening of the beaded braided tube is greater than the axial shortening of the vascular stent, the beaded braided tube is contained in the vascular stent and does not extend out of the vascular stent.

[0072] In the case where the tubular network structure of the vascular stent and the beaded braided tube is woven from two or more braided wires, the principle of axial shortening is the same as described above and will not be described in detail here.

[0073] In addition, the braiding pattern of the braided wire can be not only a triangular wave, but also a sine wave or other shapes, and also a shape of a combination of a sine wave and a triangular wave, and the triangular wave and sine wave or other shapes can be composed of waves of different sizes.

[0074] Furthermore, since both the vascular stent and the beaded braided tube are three-dimensional structures, the braided wire can be made into a spatial spiral structure to realize the vascular stent and the beaded braided tube, and its longitudinal cross-sectional projection can be the above-mentioned triangular wave or sine wave shape, so the principle of axial shortening is the same as above.

[0075] Based on the above principle, by designing the axial shortening of the vascular stent and the beaded braided tube during the release process, for example, making the axial shortening of the vascular stent during the release process less than or equal to or only slightly greater than the axial shortening of the beaded braided tube during the release process, it can be achieved that: in the compressed state, the length of the distal end of the beaded braided tube 103 extending from the distal end of the vascular stent 104 is not greater than the above first threshold, and at the same time, during the entire process of releasing the vascular stent 104 from the delivery catheter 101 until the release is completed, the length of the distal end of the beaded braided tube 103 extending from the distal end of the vascular stent 104 is not greater than the above second threshold. Among them, the first threshold can be equal to the second threshold; of course, the first threshold may also be greater than or less than the second threshold, as long as the distal end of the beaded braided tube can avoid damaging the distal blood vessel.

[0076] Specifically, assuming that the length of the beaded braided tube in the compressed state is A1, and the length after release is A2, the length of the vascular stent in the compressed state is B1, and the length after release is B2, and the length of the distal end of the beaded braided tube extending from the distal end of the vascular stent in the compressed state is A3, then:

[0077] When A3 = 5 mm, (A1-A2) ≥ (B1-B2) must be satisfied. In this case, the length of the distal end of the braided tube extending beyond the distal end of the stent is no more than 5 mm, whether in the compressed state or after release.

[0078] When A3 is less than 5mm, it is necessary to satisfy (A1-A2)-(B1-B2)≥(A3-5mm). In this case, the length of the distal end of the braided tube extending beyond the distal end of the stent in the compressed state is less than 5mm, and the length of the distal end of the braided tube extending beyond the distal end of the stent after release is not more than 5mm, that is, the axial shortening of the braided tube during the release process can be slightly smaller than the axial shortening of the stent during the release process, so that the length of the distal end of the braided tube extending beyond the distal end of the stent after release becomes slightly longer than that in the compressed state, but still does not exceed 5mm.

[0079] For the case of A3>5mm, by making the axial shortening of the beaded braided tube during the release process greater than the axial shortening of the vascular stent during the release process, it is also possible to achieve that the length of the distal end of the braided tube extending beyond the distal end of the stent after release does not exceed 5mm, that is, during the release process, the distal end of the braided tube withdraws proximally relative to the distal end of the stent instead of advancing toward the distal end. At this time, it is necessary to satisfy (A1-A2)-(B1-B2)≥(A3-5mm).

[0080] Figure 4FIG. 2 is a partial structural schematic diagram of a support system in a compressed state according to a second embodiment of the present disclosure. Figure 1 The first embodiment shown is different in that Figure 4 In the illustrated embodiment, in the compressed state, the distal end of the beaded braided tube 103 is substantially flush with the distal end of the vascular stent 104 .

[0081] In this case, during the entire process of releasing the stent, the axial shortening of the stent may be less than or equal to the axial shortening of the beaded braided tube during the release process. Thus, during the release process, the distal end of the beaded braided tube 103 will not extend beyond the distal end of the stent 104. Of course, during the entire process of releasing the stent, the axial shortening of the stent may also be slightly greater than the axial shortening of the beaded braided tube during the release process, for example, greater than 5 mm. Thus, during the release process, the distal end of the beaded braided tube 103 slightly extends beyond the distal end of the stent 104, for example, less than 5 mm. Figure 5 It is a schematic diagram showing that the distal end of the beaded braided tube does not extend out of the distal end of the vascular stent during the process of releasing the vascular stent. Figure 6 It is a schematic diagram showing that during the process of releasing the vascular stent, the distal end of the beaded braided tube slightly extends out of the distal end of the vascular stent, for example, not exceeding 5 mm. Figure 7 It is a schematic diagram showing that after the vascular stent is completely released, the distal end of the beaded braided tube slightly protrudes from the distal end of the vascular stent, for example, the protrusion does not exceed 5 mm.

[0082] According to the present disclosure, in the compressed state, the distal end of the beaded braided tube is not shorter than the distal end of the vascular stent, so as to prevent the distal end of the stent from collapsing without the support of the beaded braided tube and the resulting risk of damage to the mesh wire at the distal end of the stent.

[0083] Figure 8 FIG. 1 is a partial structural diagram of a beaded braided tube in a first state according to an embodiment of the present disclosure. Figure 8 As shown, the beaded braided tube includes at least one expandable segment 801, 802, 803, 804 arranged in sequence, wherein the expandable segments 801 and 804 are only shown in a small part, and the expandable segments 801 and 804 are Figure 8 The end not shown in the figure can also be connected with more expandable segments. The present disclosure does not limit the number of expandable segments, and the beaded braided tube can also include one, two, three, five or more expandable segments.

[0084] In some optional embodiments, the shape of the expandable segments 801, 802, 803, and 804 can be roughly spindle-shaped, that is, thicker in the middle and thinner at both ends. The expandable segments 801, 802, 803, and 804 are elastic, can be compressed, and can naturally expand and return to their original shape under the action of elasticity. In use, by squeezing the beaded braided tube at one or both ends, the middle part of the expandable segments 801, 802, 803, and 804 can be further expanded, and the diameter can be further enlarged to be used for expanding the vascular stent. In some optional embodiments, the diameter of at least one expandable segment after natural expansion is larger than the inner diameter of the vascular stent to be expanded after natural expansion. In some optional embodiments, the diameter of the expandable segment after natural expansion is larger than the inner diameter of the vascular stent after natural expansion.

[0085] Since the expandable sections 801, 802, 803, and 804 are a tubular mesh structure woven from braided wires, the beaded braided tube has good flexibility and can return to its original shape after being opened again even if it is knotted, squeezed, or stacked.

[0086] In some optional embodiments, the most distal expandable segment of the beaded braided tube according to the present disclosure adopts a dense mesh braiding structure, that is, the most distal expandable segment is braided more densely than other expandable segments, so as to prevent the diseased blood vessel plaque from falling off and blocking other blood vessels with the blood flow.

[0087] Two adjacent expandable segments among the expandable segments 801 , 802 , 803 , and 804 are connected via a contraction segment 805 .

[0088] Fig. 9 FIG. 2 is a schematic diagram of the structure of a beaded braided tube in a second state according to another embodiment of the present disclosure. Fig. 9 As shown in FIG. 1 , the beaded braided tube includes four expandable segments 901, 902, 903, and 904 arranged in sequence. The expandable segments 901, 902, 903, and 904 are connected by a contraction segment 905. The proximal end of the beaded braided tube is connected to the distal end of the delivery guide wire 102 of the stent system. By pushing the delivery guide wire 102 toward the distal end, the expandable segments 901, 902, 903, and 904 can be fully expanded to achieve the following effect: Fig. 9 The second state is shown.

[0089] exist Fig. 9In the illustrated embodiment, the diameters of the four expandable segments 901, 902, 903, and 904 after natural expansion are not equal, wherein the diameter of the expandable segment 904 at the farthest end after natural expansion is the largest, and the diameter of the expandable segment 904 after natural expansion is greater than the inner diameter of the vascular stent (not shown) after natural expansion. In some optional embodiments, the diameter of the expandable segment at the farthest end after natural expansion is 1.1-2 times the inner diameter of the vascular stent after natural expansion. In some optional embodiments, the diameter of the expandable segment 904 at the farthest end after natural expansion may also be equal to the inner diameter of the vascular stent (not shown) after natural expansion. Thus, the expandable segment 904 can be tightly combined with the vascular stent after expansion, so that the relative positions of the two are fixed. By using the delivery catheter and the delivery guide wire to push toward the far end, the four expandable segments 901, 902, 903, and 904 will expand and stack, and then the poorly adhered vascular stent part can be further supported and expanded.

[0090] In some optional embodiments, the sizes of the multiple expandable segments can be arranged in different arbitrary ways as required: it can be a number of large expandable segments (i.e., expandable segments whose maximum diameter after natural expansion is greater than or equal to the inner diameter of the vascular stent after natural expansion) starting from the farthest end, followed by a small expandable segment (i.e., expandable segments whose maximum diameter after natural expansion is less than the inner diameter of the vascular stent after natural expansion); it can also be a large expandable segment starting from the farthest end, followed by a number of small expandable segments; it can also be a large expandable segment starting from the farthest end, followed by a number of small expandable segments, and then a large expandable segment; etc. The beaded braided tube having multiple large expandable segments is advantageous in the following aspects: when the anchoring force of the large expandable segment at the farthest end or near the far end is insufficient, the large expandable segment near the proximal end can further play an anchoring role; the large expandable segment near the proximal end can anchor multiple stents that need to be expanded in stages as required, without the need to recycle the beaded braided tube into the delivery catheter and then reposition it for expansion.

[0091] Combination Figure 10-13 As shown, the embodiment of the present disclosure provides a self-expanding vascular stent, which includes a stent body 1 and a developing member 2. The stent body 1 is woven into a tubular network structure by braiding wires 11, and one end of the braiding wires 11 is a first end 111, and the other end of the braiding wires 11 is a second end 112. The developing member 2 is sleeved on the first end 111 and the second end 112 of the two intersecting braiding wires 11. The diameters of the first end 111 and the second end 112 are both smaller than the diameter of the braiding wires 11.

[0092] In some embodiments, Fig.13As shown, the first end 111 and the second end 112 can be locally processed by laser cutting, CNC machining, chemical etching, etc. to achieve the purpose of making the diameter of the first end 111 and the second end 112 smaller than the diameter of the braided wire 11.

[0093] For braided stents, the number of braided wires used is usually large, and the number of developing parts fixed at the end of the stent is also large. Therefore, by reducing the diameter of the end of the braided wire, and then sleeve the developing parts on the intersecting ends of the braided wires, the size of the developing parts is reduced, so as not to change or reduce the size of the two ends of the stent after shrinkage. This not only increases the developing property of the vascular stent, but also allows the vascular stent to pass more smoothly in the catheter.

[0094] Continue to refer Fig.13 , transition chamfers 13 are provided between the braided wire 11 and the first end 111, and between the braided wire 11 and the second end 112. When the first end 111 and the second end 112 of the braided wire 11 are locally processed, a transition chamfer 13 is integrally formed between the main body of the braided wire 11 and the first end 111, and a transition chamfer 13 is integrally formed between the main body of the braided wire 11 and the second end 112. Providing transition chamfers between the braided wire and the first end, and between the braided wire and the second end can improve the structural performance of the braided wire after the diameter of the first end and the diameter of the second end are reduced, reduce the risk of fracture between the first end, the second end and the braided wire, and ensure that the end of the vascular stent has sufficient supporting force.

[0095] In some embodiments, Fig.14 As shown, the general shape of the developing member 2 is cylindrical. The developing member 2 is integrally formed with a through hole 22 along its axial direction. The first end 111 (or the second end 112) of the intersecting braided wire 11 simultaneously enters the through hole 22 of the developing member 2 to complete the sleeve of the developing member 2 on the braided wire 11.

[0096] Combination Fig.13 and Fig.14 The first end 111 and the second end 112 are integrally formed with rounded corners 23 to facilitate the first end 111 and the second end 112 to smoothly enter the through hole 22 of the developing component 2.

[0097] In some embodiments, Fig.15As shown, there is an angle between the transition chamfer 13 and the axis of the braided wire 11, that is, the angle can be regarded as the angle α of the transition chamfer. In one example, the angle α of the transition chamfer is the angle formed by the plane where the transition chamfer 13 is located and the axis of the braided wire 11. In another example, the angle α of the transition chamfer is the angle formed by the tangent plane of the transition chamfer 13 and the axis of the braided wire 11. The value range of the angle α of the transition chamfer is 20°-90°. Optionally, the angle α of the transition chamfer is in the range of 30°-60°; optionally, the angle α of the transition chamfer is in the range of 30°-50°; optionally, the angle α of the transition chamfer is in the range of 30°-45°; optionally, the angle α of the transition chamfer is in the range of 30°-40°; optionally, the angle α of the transition chamfer is in the range of 30°-35°; optionally, the angle α of the transition chamfer is in the range of 35°-55°; optionally, the angle α of the transition chamfer is in the range of 40°-50°. In some embodiments of the present disclosure, the angle α of the transition chamfer is in the range of 30°-60°, which can improve the structural performance of the first end and the second end of the braided wire, improve the anti-fracture performance between the first end, the second end and the braided wire body, and allow the developer to be fixed to the end of the braided wire, so as to form a mutual conflict with the transition chamfer 13 of the braided wire, thereby improving the overall reliability.

[0098] Continue to see Fig.15 In one example, the diameter of the braided wire 11 is d, and the diameters of the first end 111 and the second end 112 are D1. In one example, the diameters of the first end 111 and the second end 112 are both D1. Here, the structure of the braided wire used to weave the vascular stent is improved, and the diameters of the first end 111 and the second end 112 are limited, which can ensure that the diameter of the vascular stent will not increase after shrinkage while increasing the developability of the vascular stent.

[0099] In one example, combining Fig.15 As shown, the length of the first end 111 and / or the second end 112 is L0, 0.3 mm ≤ L0 < 10 mm.

[0100] The length of the first end 111 or the length of the second end 112 of the braided wire 11 is limited here, which can ensure that the connection between the two adjacent braided wires 11 woven into the stent body 1 is more solid, thereby increasing the overall support force of the vascular stent. If the length L0 of the first end is too short, the connection structure of the two adjacent braided wires is loose, which will cause the vascular stent as a whole to be more easily deformed and decomposed. If the length L0 of the first end is too long, not only will the materials of the braided wire and the developer be wasted, increasing the manufacturing cost, but also the supporting performance of the two ends of the vascular stent will be reduced, reducing the mutual support force between the braided wires. According to the specific size of the stent, L0 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm and 10mm.

[0101] In one example, combining Fig.16 As shown, at least two braided wires 11 form a braiding group 12; the stent body 1 is braided into a tubular mesh structure by the braiding group 12.

[0102] In the present embodiment, a braided group 12 is formed by two braided wires 11. For example, two braided wires 11 can form a braided group 12 by integral molding, or two braided wires 11 can form a braided group 12 by bonding, or two braided wires 11 can form a braided group 12 by welding, or two braided wires 11 conflicting with each other can be regarded as a braided group 12. The braided group 12 is composed of two braided wires 11; the stent body 1 is woven into a tubular mesh structure by the braided group 12. The supporting force of the stent body woven by the braided group is stronger than the supporting force of the stent body woven by the braided wires. In other embodiments, the braided group 12 is composed of more than two braided wires 11, for example, the braided group is composed of three braided wires 11; the stent body 1 is woven into a tubular mesh structure by the braided group.

[0103] In one example, combining Fig.17 , Fig.18 As shown, the connection method between the first end 111 and / or the second end 112 and the developer 2 includes gluing and / or welding. In one example, the connection method between the first end 111 and the developer 2 includes gluing. In another example, the connection method between the second end 112 and the developer 2 includes welding. In another example, the connection method between the first end 111 or the second end 112 and the developer 2 includes gluing and welding. The connection between the braided wire and the developer can be made more secure by gluing or welding.

[0104] In some embodiments, when the developer 2 is fixed to the intersecting braided wires by a low-viscosity, fluid adhesive, the adhesive may accumulate and solidify at the intersection of the developer and the braided wires, and the diameter near the accumulated adhesive may be slightly larger than the diameter of the developer 2, which is not conducive to reducing the overall diameter of the stent after shrinkage. By setting the transition chamfer 13, the adhesive can be prevented from accumulating at the above-mentioned intersection, so that the adhesive is concentrated in the bonded area to solidify. The value range of the angle α of the transition chamfer is 20°-90°, and 30°-60° can better prevent the diameter of the adhesive from increasing after solidification, for example, 30°, 35°, 40°, 45°, 50°, 55° and 60°.

[0105] In this embodiment, the first end 111 (or the second end 112) of the intersecting braided wire 11 enters the through hole 22 of the developer 2 at the same time, and then is connected to each other by welding, adhesive or similar bonding mechanism. A joint 14 is formed after the first end 111 (or the second end 112) is welded or bonded to the developer 2. The joint 14 is produced by gluing or welding, which can make the connection between the first end 111 and / or the second end 112 and the developer 2 more secure. The cross-sectional shape of the joint 14 is any one of semicircular, semi-elliptical or semi-circular shapes. This smooth joint can reduce the damage of the two ends of the vascular stent to the vascular wall, and also reduce the damage of the vascular stent to the inner wall of the catheter that transports the vascular stent. In some embodiments of the present disclosure, the material of the braided wire 11 includes a metal material. The metal material includes memory metal and the like. The braided wire 11 is made of materials such as titanium, nickel-titanium alloy, stainless steel, platinum-tungsten alloy, platinum, platinum-iridium alloy, cobalt-chromium alloy, etc. When the braided wire is made of cobalt-chromium alloy and nickel-titanium alloy materials, it can improve biocompatibility.

[0106] In some embodiments of the present disclosure, Fig.19 , Fig. 20 , Fig.21 As shown, the ports at one or both ends of the bracket body 1 are outwardly expanded.

[0107] In this embodiment, the ports at one or both ends of the stent body 1 are in a trumpet shape, and the developing member 2 fixed at the end of the stent is radiated outward along the axis of the blood vessel stent. The port of the stent is designed in a trumpet shape, which is convenient for anchoring the blood vessel stent to the blood vessel. When or after the blood vessel stent is released, the stent is not easily displaced, and the developing member of the blood vessel stent acts as an anchor point.

[0108] In some embodiments, the developing member 2 includes any one of a spring developing coil 2a, a developing ring 2c, and a developing heat shrink tube, or any combination of multiple thereof.

[0109] In this embodiment, combined with Figure 22-Figure 26As shown, when the developing member 2 is a spring developing coil 2a, the length of the spring developing coil 2a is the same as the length of the first end 111 (or the second end 112), so that the spring developing coil 2a is bonded or welded to the first end 111 (or the second end 112) of the braided wire 11, because the braided wire and the spring developing coil have good ductility, which can make the connection between the spring developing coil 2a and the braided wire 11 more secure. The internal space of the spring developing coil 2a can be regarded as a through hole 22. Since the spring developing coil 2a is formed by winding the developing metal wire 21, and the cross-section of the developing metal wire 21 is circular, the edge of the spring developing coil 2a is smooth. The spring developing coil is used to fix the first end or the second end of the braided wire. In clinical applications, the spring developing coil is not prone to deformation such as sheath wire and bending.

[0110] In this embodiment, combined with Fig.14 As shown, when the developing member 2 is a developing ring 2c, the length of the developing ring 2c is the same as the length of the first end 111 or the second end 112, so that the developing ring 2c and the first end 111 or the second end 112 of the braided wire 11 can be bonded or welded. The inner ring hole of the developing ring 2c can be regarded as a through hole 22. Fillets 23 are integrally formed at both ends of the developing ring 2c and at the opening of the through hole 22, so that the first end 111 of the braided wire 11 can be inserted into the through hole 22 of the developing ring.

[0111] In one example, combining Fig.14 , Fig.15 As shown, the inner diameter of the developing member 2 is ID0, 2*D1≤ID0≤3*D1.

[0112] In this embodiment, combined with Fig.23 As shown, ID0=2*D1. The first ends 111 (or the second ends 112) of the two intersecting braided wires 11 collide with each other and are inserted into the through hole of the developer 2. At this time, the inner diameter ID0 of the developer is twice the diameter D1 of the first end 111 or the second end 112. The inner diameter of the developer 2 (i.e., the aperture of the through hole 22 of the developer 2) is limited here to ensure that the first end 111 can smoothly enter the through hole 22 of the developer 2. If the inner diameter of the developer 2 is too large, after the first ends or the second ends of the two adjacent braided wires 11 enter the through hole 22 of the developer 2, there is still a lot of room for movement in the through hole, resulting in a loose structure and uneven force at the connection between the two adjacent braided wires and the developer.

[0113] In this embodiment, combined with Figure 24-25As shown, ID0=3*D1. In one example, the first end or the second end of the braided wire is arranged coaxially with the braided wire body. When the first ends 111 (or the second ends 112) of the two intersecting braided wires 11 collide with each other, the distance between the adjacent first ends 111 or the second ends 112 is D1, and the two adjacent braided wires are inserted into the through hole of the developer 2. At this time, the inner diameter ID0 of the developer is three times the diameter D1 of the first end 111 or the second end 112. In one example, when the vascular stent is in a compressed state, the two adjacent braided wires are in a compressed state. Fig.24 When the vascular stent is in a state of transition from a compressed state to an expanded state, the two adjacent braided wires are in a state as shown in FIG. Fig.25 Such a setting can allow elastic deformation between adjacent braided wires and the developing member, making the connection more stable and firm, thereby increasing the service life of the stent. Fig.26 , Fig. 27 As shown, when the developing member 2 is a spring developing coil 2a, the diameter of the developing wire 21 wound into the spring developing coil 2a is D2. The diameter of the developing metal wire wound into a spring developing coil is limited here, which can ensure the size of the spring developing coil and enable the spring developing coil to fix the first end or the second end of the braided wire without increasing the diameter of the vascular stent after contraction, while also increasing the developing properties of both ends of the vascular stent.

[0114] In this embodiment, when the developing member 2 is a spring developing coil 2a, the spring developing coil 2a fixes the adjacent braided wires 11, and then a joint 14 is formed at the connection thereof by gluing or welding. This can make the first end 111, the second end 112 of the end of the vascular stent and the developing metal wire 21 of the spring developing coil smoother, reduce damage to the blood vessel wall, and also enable the vascular stent to pass more smoothly in the catheter.

[0115] Continue to refer Fig.26 In this embodiment, the inner diameter and outer diameter of the spring developing coil 2a gradually increase from the end of the braided wire toward the middle of the braided wire. This design can avoid excessive accumulation of adhesive at the end position, which is beneficial to the reduction of the overall diameter after the bracket shrinks.

[0116] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present disclosure is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) by each other.

Claims

1. A stent system, comprising a delivery catheter, a delivery guide wire, a beaded braided tube and a vascular stent, The proximal end of the beaded braided tube is connected to the distal end of the delivery guide wire. The beaded braided tube and the vascular stent are both tubular mesh structures woven from braided wires. The beaded braided tube is located in the vascular stent. Both the beaded braided tube and the vascular stent can be located in the delivery catheter and be in a compressed state, and can be released from the delivery catheter and expanded. in, In the compressed state, the length of the distal end of the beaded braided tube extending from the distal end of the vascular stent is not greater than a first threshold, and during the process of the vascular stent being released from the delivery catheter until the release is completed, the length of the distal end of the beaded braided tube extending from the distal end of the vascular stent is not greater than a second threshold, and both the first threshold and the second threshold are not greater than 5 mm, and During the process of releasing from the compressed state until the release is completed, the vascular stent is shortened in axial direction to be less than or equal to the shortened length of the bead braided tube in axial direction.

2. The support system according to claim 1, wherein: The first threshold is greater than the second threshold.

3. The support system according to claim 1, wherein: The first threshold is equal to the second threshold.

4. The bracket system according to claim 1, wherein: The first threshold is 5 mm, wherein the second threshold is 5 mm.

5. The support system according to claim 4, wherein: Assuming that the length of the beaded braided tube in the compressed state is A1, and the length after release is A2, the length of the vascular stent in the compressed state is B1, and the length after release is B2, and the length of the distal end of the braided tube extending out of the distal end of the vascular stent in the compressed state is A3, then: When A3 = 5 mm, (A1-A2) ≥ (B1-B2); When A3<5mm, (A1-A2)-(B1-B2)≥(A3-5mm).

6. The bracket system according to claim 1, wherein: In the compressed state, the distal end of the beaded braided tube is substantially flush with the distal end of the vascular stent.

7. The support system according to claim 1, wherein: The braided wires are made of metal material.

8. The support system according to claim 7, wherein: The metal material includes memory metal.

9. The support system according to claim 8, wherein: The memory metal includes one or more of cobalt-chromium alloy, platinum-tungsten alloy and nickel-titanium alloy.

10. The bracket system according to claim 1, wherein: The beaded braided tube comprises at least one expandable segment, wherein a diameter of at least one expandable segment after natural expansion is larger than an inner diameter of the vascular stent after natural expansion.

11. The support system according to claim 10, wherein: The beaded braided tube includes: at least two expandable sections; and a contraction section located between two adjacent expandable sections.

12. The support system according to claim 11, wherein: The diameter of the most distal expandable section after natural expansion is larger than the inner diameter of the vascular stent after natural expansion.

13. The support system according to claim 12, wherein: The diameter of the most distal expandable section after natural expansion is 1.1-2 times the inner diameter of the vascular stent after natural expansion.

14. The bracket system according to claim 11, wherein: The diameter of the expandable section after natural expansion is greater than the inner diameter of the vascular stent after natural expansion.

15. The bracket system according to claim 11, wherein: The distal-most expandable segment is braided more densely than the other expandable segments.

16. The bracket system according to claim 1, wherein: The vascular stent is a self-expanding vascular stent, and the vascular stent comprises: a stent body, which is woven into a tubular mesh structure by braiding wires, wherein the braiding wires include a first end, a second end opposite to the first end, and a portion between the first end and the second end; and a support developing member, sleeved on the first end of the intersecting braided wires, and / or sleeved on the second end of the intersecting braided wires, The first end and / or the second end has a first diameter, a portion between the first end and the second end has a second diameter, and the first diameter is smaller than the second diameter.

17. The support system according to claim 16, wherein: The first diameter is less than or equal to half of the second diameter.

18. The support system according to claim 16, wherein: At least two braided wires form a braiding group; the stent body is braided into a tubular mesh structure by the braiding group.

19. The bracket system according to claim 16, wherein: The first end and / or the second end are connected to the developing member by gluing and / or welding.

20. The bracket system of claim 16, wherein: A joint is formed at a connection between the first end and / or the second end and the developing member.

21. The support system according to claim 20, wherein: The cross-sectional shape of the joint is any one of semicircular, semi-elliptical or semicircular.

22. The bracket system of claim 16, wherein: A transition chamfer is provided between the braided wire and the first end and / or the second end.

23. The support system according to claim 22, wherein: The angle α of the transition chamfer is in the range of 20°-90°.

24. The stent system of claim 22, wherein: The angle α of the transition chamfer ranges from 30° to 60°.

25. The stent system of claim 16, wherein: The length of the first end and / or the second end is L0, 0.3 mm ≤ L0 < 10 mm.

26. The stent system of claim 16, wherein: The material of the braided wire includes metal material.

27. The stent system of claim 26, wherein: The metal material is selected from one or more of titanium, nickel-titanium alloy, stainless steel, platinum-tungsten alloy, platinum, platinum-iridium alloy and cobalt-chromium alloy.

28. The stent system of claim 16, wherein: The ports at one end or both ends of the bracket body are outwardly expanded.

29. The support system of claim 28, wherein: The port is in a trumpet shape.

Images