Conveyor and support system

Abstract

The present application is suitable for the technical field of medical devices, and provides a delivery device and a stent system, wherein the distal end of the support tube along its length direction comprises a first tube segment and a second tube segment, the first tube segment is located at the distal end of the second tube segment, the first tube segment comprises a first support structure, the second tube segment comprises a second support structure, and under the same force, the bending degree of the first support structure is greater than that of the second support structure. In the present application, the tube body of the first tube segment at the distal end of the delivery sheath tube has better bending property compared with the tube body at the proximal end, so that the tube body at the distal end can be bent better, so that the whole delivery sheath tube is convenient to bend into the branch blood vessel.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, and in particular relates to a delivery device and support system. Background Technology

[0002] Vascular stents are typically pre-loaded outside the body via a delivery system, and then released into the body by withdrawing the delivery sheath or stent restraint line from the delivery system via a handle.

[0003] During the delivery process, the length of the delivery sheath increases as the path extends. To conform to the vascular structure, the delivery sheath will twist and deform. If the target location for stent deployment is a branch vessel, the degree of twisting of the delivery sheath will be further increased. Figure 1 As shown, the delivery sheath 30 enters the branch vessel 20 through the main vessel 10. If the distal end of the delivery sheath 30 has good flexibility, it will slide into the branch vessel 20 along the opening (along...). Figure 1 (Slide in the direction indicated by the arrow). If the distal end of the delivery sheath 30 has poor bending performance, regardless of how it is pushed externally, the distal end of the delivery sheath 30 will abut at a certain point at the opening of the branch vessel 20 (e.g., ...). Figure 2 (Point A marked), the delivery sheath 30 undergoes bending deformation within the main vessel 10 (along...) Figure 2 (The direction indicated by the arrow is deformed), the delivery sheath 30 cannot enter the branch vessel 20.

[0004] In summary, when the target location for vascular stent deployment is a branch vessel, the poor flexibility of the distal end of the delivery sheath makes it difficult to enter the branch vessel. Summary of the Invention

[0005] The purpose of this invention is to provide a delivery device and stent system that addresses the technical problem that existing delivery sheaths are not easily inserted into branch blood vessels.

[0006] The present invention is implemented as follows: it includes a delivery sheath, the delivery sheath including an outer tube and a support tube disposed in the outer tube, the distal end of the support tube including a first tube segment and a second tube segment along its length direction, the first tube segment being located at the distal end of the second tube segment, the first tube segment including a first support structure, the second tube segment including a second support structure, and under the same force, the curvature of the first support structure is greater than the curvature of the second support structure.

[0007] The second pipe section also includes a reinforcing structure disposed on the second support structure. The reinforcing structure is used to increase the elongation resistance of the second pipe. The reinforcing structure includes at least one second reinforcing member, which extends along the axial direction of the second support structure and is located on one side of the second support structure. The second reinforcing member is used to guide the second support structure to bend toward the branch vessel.

[0008] Furthermore, the second support structure has greater resistance to axial elongation than the first support structure.

[0009] Furthermore, the proximal end of the first support structure is connected to the second support structure through a third support structure, or a gap is left between the first support structure and the second support structure.

[0010] Furthermore, the first support structure is a spiral structure or a braided mesh structure, and / or the second support structure is a spiral structure or a braided mesh structure.

[0011] Furthermore, the reinforcing structure includes a plurality of first reinforcing members distributed along the axial direction, and the spacing between the plurality of adjacent first reinforcing members is equal.

[0012] Furthermore, the spacing between adjacent first reinforcing members gradually decreases from the near end of the second support structure to the far end of the second support structure.

[0013] Furthermore, there are multiple second reinforcing members, which are arranged circumferentially along the second support structure.

[0014] Furthermore, the diameter of the second reinforcing member gradually decreases from the proximal end of the second support structure to the distal end of the second support structure.

[0015] The present invention also provides a stent system comprising a vascular stent and a delivery sheath as described above, wherein the vascular stent is delivered to a desired location via the delivery device.

[0016] The beneficial effects of the present invention are as follows: When the delivery device of the present invention is used, the curvature of the first support structure is greater than that of the second support structure, and the first support structure is located at the distal end of the second support structure. This makes the tube body of the first segment at the distal end of the delivery sheath more flexible than that at the proximal end, allowing the distal tube body to bend more easily, so that the entire delivery sheath can bend into the branch blood vessel. When the distal end of the delivery sheath enters the branch blood vessel, the tube body of the first segment at the distal end of the delivery sheath can bend, ensuring that the distal end of the delivery sheath can slide from the main blood vessel into the branch blood vessel, avoiding the inability of the distal end of the delivery sheath to enter the branch blood vessel due to poor bending performance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the normal entry of the delivery sheath into the branch blood vessel in the delivery device of the background technology;

[0018] Figure 2 This is a schematic diagram illustrating the operation of a delivery sheath in a delivery device in the background technology, where the sheath cannot enter a branch blood vessel.

[0019] Figure 3 This is a schematic diagram of the structure of the distal end of the conveying sheath in the conveyor of Example 1;

[0020] Figure 4 This is a schematic diagram of the bending angle of the first section of the conveying sheath in the conveyor of Embodiment 1;

[0021] Figure 5 This is a schematic diagram of the bending angle of the second section of the conveying sheath in the conveyor of Embodiment 1;

[0022] Figure 6 This is a schematic diagram of the structure of the distal end of the delivery sheath in another embodiment of the conveyor;

[0023] Figure 7 This is a schematic diagram of the first structure of the distal end of the delivery sheath in another embodiment of the conveyor;

[0024] Figure 8 This is a schematic diagram of a second structure of the distal end of the delivery sheath in another embodiment of the conveyor;

[0025] Figure 9 This is a schematic diagram of a third structure at the distal end of the delivery sheath in another embodiment of the conveyor;

[0026] Figure 10 This is a schematic diagram of a fourth structure at the distal end of the delivery sheath in another embodiment of the conveyor;

[0027] Figure 11 This is a schematic diagram of the structure of the distal end of the delivery sheath in another embodiment of the conveyor;

[0028] Figure 12 This is a schematic diagram of the structure of the distal end of the delivery sheath in another embodiment of the conveyor;

[0029] Figure 13 This is a schematic diagram of the structure of the distal end of the conveying sheath in the conveyor of Example 2;

[0030] Figure 14 This is a schematic diagram of the structure in Embodiment 3 where the center yarn is disposed on the first support structure;

[0031] Figure 15This is a structural schematic diagram of the spacing distribution of the first reinforcing member in a conveyor according to another embodiment;

[0032] Figure 16 This is a schematic diagram of the bending of a conveyor sheath with a first reinforcing member in another embodiment of the conveyor;

[0033] Figure 17 This is a schematic diagram of the bending of a conveyor sheath without a center yarn in another embodiment of the conveyor;

[0034] Figure 18 This is a schematic diagram of the bending of the conveyor with a second reinforcing member in Embodiment 4;

[0035] Figure 19 This is a schematic diagram of a bent conveyor with two second reinforcing members in another embodiment. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or may have an intervening component present. When a component is referred to as "connected to" another component, it can be directly connected to the other component or may have an intervening component present.

[0038] It should also be noted that the directional terms such as left, right, up, and down in this embodiment are only relative concepts or are based on the normal use of the product, and should not be considered as restrictive.

[0039] It should be noted that in the field of interventional medical devices, the end of a medical device implanted in the human or animal body that is closer to the operator is generally called the "proximal end," and the end that is farther from the operator is called the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of a medical device are defined. "Axial direction" generally refers to the length direction of the medical device during delivery, and "radial direction" generally refers to the direction of the medical device perpendicular to its "axial direction." Based on this principle, the "axial direction" and "radial direction" of any component of a medical device are defined.

[0040] Example 1

[0041] As attached Figures 3 to 8As shown, this embodiment provides a delivery device, including a delivery sheath 30. The delivery sheath 30 includes a polymer tube and a support tube disposed within the polymer tube. The polymer tube includes a delivery channel for the delivery sheath 30. The delivery device loads and releases vascular stents through the delivery channel; that is, when the vascular stent is implanted in the human body, it passes through the delivery channel to reach a predetermined position and then leaves the delivery channel to complete the release and implantation. The support tube is embedded in the wall of the polymer tube, and its purpose is to improve the radial and axial strength of the delivery sheath 30, ensure that the main body of the delivery sheath 30 has certain resistance to bending and elongation, and maintain the unobstructed delivery channel so that the delivery device can load and release vascular stents.

[0042] To achieve the delivery effect of the delivery sheath 30 in this embodiment, the delivery device provided in this embodiment includes a first tube segment 20 and a second tube segment 22 at the distal end of the support tube along its length. The first tube segment 20 is located at the distal end of the second tube segment 22. The first tube segment 20 includes a first support structure 31, and the second tube segment 22 includes a second support structure 32. The curvature of the first support structure 31 is greater than that of the second support structure 32. That is, under the same radial force, the deformation of the first support structure 31 is greater than that of the second support structure 32. Since both the first support structure 31 and the second support structure 32 are tubular structures, they bend and deform under pressure, meaning the curvature of the first support structure 31 is greater than that of the second support structure 32. This arrangement allows the tube body of the first tube segment 20, located in the middle and rear section of the delivery sheath 30, to have better flexibility than the tube body located in its proximal section, enabling the middle and rear section of the tube body to bend more easily, thus facilitating the bending of the entire delivery sheath 30 into the branch blood vessel. Meanwhile, if the distal end of the delivery sheath 30 comes into contact with the opening of a branch vessel, during the continued implantation of the delivery sheath 30, due to the good bending performance of the first segment 20, the first segment 20 will bend before the second segment 22. The end of the first segment 20 will change direction due to the bending. Since the opening of the branch vessel is located on the side of the delivery sheath 30 in the main vessel, the bending direction of the first segment 20 will always be towards the branch vessel, making it easier for the first segment 20 to enter the branch vessel. This avoids the distal end of the delivery sheath 30 coming into contact with the opening of the branch vessel, and thus avoids the distal end of the delivery sheath 30 puncturing or perforating the opening of the branch vessel.

[0043] In this embodiment, the first support structure 31 is a helical structure or a braided mesh structure, and / or, the second support structure 32 is a helical structure or a braided mesh structure. The material of the first support structure 31 can be stainless steel or a nickel-titanium alloy, and the material of the second support structure 32 can be stainless steel or a nickel-titanium alloy. The first support structure 31 can be a helical structure or a braided mesh structure, and the second support structure 32 can be a helical structure or a braided mesh structure. A braided mesh structure refers to a tubular body with at least one mesh opening.

[0044] After the sheath successfully enters the branch vessel and reaches the predetermined position, the vascular stent is released. Generally, the vascular stent is released by keeping it fixed on the sheath core and moving the sheath. During the release phase, the sheath has already taken on a multi-angle curved shape within the vessel lumen. If the axial elongation resistance of the sheath is poor, the axial force applied externally to move the sheath will be offset by the bending deformation of the sheath, failing to transmit the force to the distal end of the sheath. This leads to problems such as the stent failing to be released or the release force being too large (i.e., the external handle has been pulled open, but the tip of the sheath inside the body remains stationary or moves slowly). Generally, the elongation resistance of the braided mesh structure is better than that of the helical structure, but the bending performance of the braided mesh structure is worse than that of the helical structure. Therefore, in another embodiment, to solve the problem of difficult vascular stent release, the first support structure 31 is a helical structure, and the second support structure 32 is a braided mesh structure. That is, the first support structure 31 ensures the bending performance of the distal end of the sheath, and the second support structure improves the elongation resistance of the proximal end of the distal end of the sheath.

[0045] In addition, during the implantation of the sheath into the human body, if the sheath has poor axial elongation resistance, it is easy for the sheath to become wrinkled in the blood vessels or to be unable to move in time with external thrust, resulting in inaccurate positioning of the distal end of the sheath.

[0046] In this embodiment, both the second support structure 32 and the first support structure 31 are braided mesh structures. The first support structure 31 includes multiple metal wires 341, which are woven into a mesh structure in an interlaced manner. The first support structure 31 can provide axial and radial strength, improving the sheath's resistance to stretching, thereby ensuring the accuracy of sheath entry and withdrawal while ensuring that the distal end of the delivery sheath 30 can pass through the vascular channel of the tortuous branch blood vessel.

[0047] In this embodiment, refer to Figure 4-5Although both the first support structure 31 and the second support structure 32 are braided mesh structures, they differ in that the first support structure 31 is woven from at least two metal wires, with a maximum axial angle α1 between the wires. The second support structure 32 is also woven from at least two metal wires, with a maximum axial angle α2 between the wires. α1 is greater than α2, meaning the axial angle between the wires in the first support structure 31 is greater than that in the second support structure 32. Under the same radial force, both the first and second support structures 31 undergo radial deformation. The deformation angle β1 of the first support structure 31 is greater than that of the second support structure 32, indicating that the radial deformation capacity of the first support structure 31 is greater than that of the second support structure 32. Therefore, the first support structure 31 is more prone to bending than the second support structure 32. In the sheath, this manifests as the first tube segment 20 deforming before the second tube segment 22.

[0048] Therefore, when the sheath reaches the opening of the branch vessel, the first support structure 31 deforms before the second support structure 32. Since the opening of the branch vessel is located on the side of the artery / vein, the end of the sheath is deformed by pressure after contacting the opening of the branch vessel. The radial component of the pressure along the sheath causes the end of the sheath to deform. The first tube segment 20 bends towards the branch vessel, which facilitates the end of the sheath (first tube segment 20) to enter the branch vessel.

[0049] Similarly, since the axial interfilament angle of the first support structure 31 is greater than that of the second support structure 32, under the action of the same axial force, the first support structure 31 and the second support structure 32 undergo axial deformation. The axial deformation of the first support structure 31 is also greater than that of the second support structure 32. That is, the axial deformation capacity of the first support structure 31 is greater than that of the second support structure 32. In other words, the axial elongation resistance of the second support structure 32 is stronger than that of the first support structure 31. Therefore, the second support structure 32 can accurately transmit external operating actions to the distal end of the sheath.

[0050] In this embodiment, a transition section 21 is provided between the first pipe section 20 and the second pipe section 22, combined with... Figure 6In this embodiment, the transition section 21 is filled with a flexible polymer material tube, such as polyurethane (TPU) or silicone (PDMS), giving the transition section high flexibility. That is, the first support structure 31 and the second support structure 32 are connected by a flexible section 342. Because the flexible section of the transition section 21 ensures maximum flexibility of the sheath at the transition section 21 position, the bendability of the transition section 21 is greater than that of the first tube section 20 and simultaneously greater than that of the second tube section 22. This ensures that during the process of the sheath entering the human body, the maximum bending angle of the sheath end, i.e., the first tube section 20, is increased. In other words, when the sheath reaches its maximum bending state, the maximum bending angle of the sheath end is greater than the sum of β1 + β2.

[0051] Furthermore, the length of the transition segment 21 is less than the length of the first segment 20 and the second segment 22, so that when the sheath bends, the angle change from the first segment 20 to the second segment 22 is smoother and more easily adapts to the vascular environment.

[0052] In another embodiment, the transition section 21 is left empty, that is, there is a gap between the first support structure 31 and the second support structure 32.

[0053] In another embodiment, the transition section 21 also includes a support structure. For the transition section 21, the axial inter-filament angle of the support structure within the transition section 21 is between the first support structure 31 and the second support structure 32, ensuring that the deformation of the sheath end always maintains a stable arc shape and is less prone to wrinkling. Specifically, refer to... Figure 7 As shown, both the first support structure 31 and the second support structure 32 are braided structures, and the included angle between the filaments of the first support structure 31 is greater than that of the second support structure 32. This makes the first pipe segment 20 where the first support structure 31 is located more prone to bending than the second pipe segment 22 where the second support structure 32 is located, and the axial extension of the first pipe segment 20 is weaker than that of the second pipe segment 22.

[0054] The transition section 21 includes a transition support structure 211, which is also a braided structure. The inter-filament angle of the transition support structure 211 is smaller than that of the first support structure 31, but larger than that of the second support structure 32. Therefore, the bending performance of the first tube section 20 is greater than that of the transition support 21 and also greater than that of the second tube section 22. The axial elongation resistance of the first tube section 20 is weaker than that of the transition section 21 and also weaker than that of the second tube section 22. In actual use, the bending of the sheath will be relatively smooth, with a low probability of wrinkling, and the force transmission will be more stable.

[0055] In another embodiment, the transition section 21 can be selected from different transition support structures, and the first pipe section 20 can also be selected from different first support structures, as shown in the reference. Figure 8-10It can be seen that the transition section 21 can be a single-helix transition support structure 212, a double-helix transition support structure 213, or a parallel transition support structure 214. Simultaneously, the first tube section 20 can use a woven mesh structure first support structure 31 or a helical structure first support structure 31'. When there is a significant difference in the mechanical properties of the first tube section 20 and the second tube section 22, stress concentration may occur at the boundary between them due to the difference in elongation and bending resistance. This can lead to wrinkles or bends in the sheath at that location, affecting the successful delivery of the implant. Therefore, the transition section 21 also serves as an intermediate force transmission carrier, preventing wrinkles or bends in the sheath.

[0056] In another embodiment, such as Figure 11-12 As shown, the sheath has no transition section; that is, the distal end of the first support structure 31 is welded to the second support structure 32, or the distal end of the first support structure 31 is connected to the second support structure 32 through the developing ring 301. The distal end of the first support structure 31 is directly welded to the second support structure 32, or the threads of the distal end of the first support structure 31 and the proximal end of the second support structure 32 are welded or pressed under the developing ring 301. The developing ring 301 is provided to facilitate the display of the position of the delivery sheath 30 during imaging. When the connection between the first support structure 31 and the second support structure 32 is separated by a flexible section 342, there is no need for the delivery sheath 30 to be bent at the flexible section 342.

[0057] Furthermore, the polymer tube includes an inner tube and an outer tube. The inner tube forms the delivery channel of the delivery sheath 30, the support tube is located outside the inner tube, and the outer tube covers the support tube and the inner tube.

[0058] Typically, the delivery sheath 30 is formed by hot-melt bonding of an outer tube and an inner tube. The outer tube has good biocompatibility and can be made of polymer materials such as elastic nylon, polyethylene, or thermoplastic polyurethane. The inner tube is commonly made of PTFE (Polytetrafluoroethylene), while the outer tube is made of Pebax or nylon. The added first support structure 31 and second support structure 32 are used to improve the sheath's own flexural strength and axial mechanical transmission performance.

[0059] The present invention also provides a stent system, wherein: a vascular stent and a delivery sheath 30 as described above are provided, the vascular stent being delivered to a desired location via a delivery device.

[0060] Taking the use of vascular stent systems to treat branch vascular diseases as an example, the following explanation of its usage process is provided:

[0061] Step 1: Stent delivery. Specifically, the soft tip of the guidewire is inserted into the guidewire lumen through the proximal end of the delivery sheath 30. The delivery sheath 30 can travel along the guidewire from the main vessel 10 to the branch vessel. When the delivery sheath 30 enters the branch vessel, the curvature of the first support structure 31 of the first segment 20 at the distal end of the delivery sheath 30 is greater than the curvature of the second support structure 32 of the second segment 22, thereby facilitating the distal end of the delivery sheath 30 to slide into the branch vessel.

[0062] Step 2: Stent Deployment. After the vascular stent has been delivered to the intended location, it is released from the delivery sheath 30 to isolate the lesion site in the branch vessel.

[0063] The third step is to remove the guide wire and the delivery device.

[0064] Example 2

[0065] like Figure 13 As shown, in this embodiment, the first support structure 31 includes a spiral structure 343, which has better bending performance than the braided mesh structure.

[0066] Furthermore, the bending capacity of the first support structure can be changed by adjusting the pitch L of the adjacent spirals and the tilt angle γ of the spirals. Specifically, the bending capacity of the first support structure 31 is enhanced when the pitch L increases and / or the tilt angle γ increases.

[0067] Furthermore, the helical structure can be constructed as a spring structure, which can stably transmit axial force and has good bending performance.

[0068] In another embodiment, both the first support structure 31 and the second support structure 32 are spring structures.

[0069] Example 3

[0070] like Figures 14 to 17 As shown, in this embodiment, the second pipe section also includes a reinforcing structure 33, which is disposed on the second support structure 32. The reinforcing structure 33 is used to increase the elongation resistance of the second pipe section. The reinforcing structure 33 is a spiral metal wire structure, which can be made of yarn. In particular, the diameter of the yarn is smaller than the wire diameter of the first support structure 31 and the second support structure 32, and it has the characteristics of low profile, softness and elongation resistance. The material is generally selected from high molecular fiber filaments.

[0071] The yarn can be threaded through the surface of the second support structure 32, or it can be tied, attached, or bonded to the surface of the second support structure 32.

[0072] In this embodiment, the reinforcing structure 33 includes a plurality of first reinforcing members 331, which are arranged along the axial direction of the second support structure 32. The first reinforcing members 331 are yarns or parts of yarns wound on the second support structure 32. One or more yarns extend axially along the second support structure 32 and surround the surface of the second support structure 32, attaching to or passing through the surface of the second support structure 32 in a spiral shape. This can increase the anti-elongation performance of the distal end of the delivery sheath 30 to a certain extent.

[0073] With the reinforcement structure 33, the elongation resistance of the middle and rear sections of the tube 312 is greater than that of the front section of the tube 311. When the distal end of the delivery sheath 30 bends, the greater elongation resistance of the middle and rear sections of the tube 312 facilitates the transfer of force to the sheath tip (stent loading area), avoiding problems such as excessive release force or failure to release the vascular stent during deployment, thus facilitating the release of the vascular stent in the delivery sheath 30.

[0074] Furthermore, multiple first reinforcing members 331 are evenly distributed in an array within the second support structure 32.

[0075] It should be noted that the entire reinforcing structure 33 can also be a multi-helix structure, that is, the spacing between multiple adjacent first reinforcing members 331 in the reinforcing structure 33 is not equal. In this embodiment, the spacing between adjacent first reinforcing members 331 gradually decreases from the proximal end of the second support structure 32 to the distal end of the second support structure 32, thereby improving the elongation resistance of the distal end of the sheath.

[0076] Among them, such as Figure 15 As shown, the distance between adjacent first reinforcing members 331 near the far end of the second support structure 32 is the first distance d1, and the distance between adjacent first reinforcing members 331 near the near end of the second support structure 32 is the second distance d3. The first distance d1 is smaller than the second distance d3.

[0077] The spacing between adjacent first reinforcing members 331 gradually decreases from the near end to the far end of the second support structure 32. The spacing between adjacent first reinforcing members 331 located in the middle of the second support structure 32 is d2.

[0078] Furthermore, in another embodiment, the spacing between the first reinforcing members 331 is adjustable, allowing the first reinforcing members 331 to better conform to the bending of the sheath. However, the spacing between adjacent first reinforcing members 331 always satisfies d1 < d2 < d3, thus providing axial support for the bending of the distal end of the delivery sheath 30 on the one hand, and further improving the axial tensile strength of the proximal segment of the distal end of the delivery sheath 30 on the other hand. Figure 16As shown, after the sheath bends at its end, the deflection angles of the proximal, middle, and distal ends of the second tube segment satisfy θ1 > θ2 > θ3, and the θ3 angle is close to 0°, making it less likely for local bulges to occur and avoiding... Figure 2 If bending deformation occurs, and the deflection angle is too large, such as... Figure 17 As shown, at this time, the angle θ3' between the proximal end of the second segment of the delivery sheath and the centerline is negative, while the deflection angle θ1' of the first segment of the delivery sheath and the deflection angle θ2' of the distal end of the second segment are still positive. That is, the first segment can deflect more than 90 degrees of obtuse angle relative to the proximal end of the guidewire.

[0079] Example 4

[0080] like Figure 18 In this embodiment, unlike embodiment 3, the reinforcing structure includes at least one second reinforcing member 332. The second reinforcing member 332 is disposed along the axial direction of the second supporting structure 32 and is used to guide the second supporting structure 32 to bend towards the branch blood vessel. Multiple second reinforcing members are distributed parallel to the surface of the second supporting structure 32 or are arranged intersectingly on the second supporting structure 32, such as... Figure 18 As shown, at least one yarn arranged axially passes through the middle and rear section of the conveying sheath 30.

[0081] In this embodiment, the second reinforcing member 332 is a yarn. When the yarn is located on one side of the delivery sheath 30 and extends to the transition section 21, when the delivery sheath 30 bends along the opposite side of the yarn, the distal end of the delivery sheath 30 can bend smoothly and transition smoothly with the transition section 21, providing axial support for the front section of the sheath. In other words, during implantation, one side of the branch vessel is placed on the opposite side of the second reinforcing member 332 of the sheath 30, so that the axial resistance to elongation of the sheath 30 is preserved to the greatest extent without affecting the bending performance of the delivery sheath 30.

[0082] In another embodiment, there are multiple second reinforcing members 332, which are arranged circumferentially along the second support structure 32. Multiple yarns can be used when the support of a single yarn is insufficient.

[0083] In another embodiment, two second reinforcing members 332 are provided. A yarn is provided on one side of the conveying sheath 30 as the first second reinforcing member 332, and another yarn is provided on the opposite side of the conveying sheath 30 as the second second reinforcing member 332. Figure 19 As shown, the two yarns are located on opposite sides of the delivery sheath. If the distal end of the sheath is bent along a direction perpendicular to the plane formed by the two yarns, the transition section 21 will be smooth and the delivery sheath 30 will bend smoothly.

[0084] In another embodiment, the diameter of the second reinforcement 332 gradually decreases from the proximal end of the second support structure 32 to the distal end of the first support structure (or the yarn in the adjacent transition section is made thinner), while the area away from the yarn gradually increases in size, in order to reduce the adverse effects that may be caused by the directionality.

[0085] When the delivery device of the present invention is used, the curvature of the first support structure 31 is greater than that of the second support structure 32, and the first support structure 31 is located at the distal end of the second support structure 32. This allows the tube body of the first segment 20 at the distal end of the delivery sheath 30 to have better curvature than the tube body at the proximal end, enabling the distal tube body to bend more easily. This facilitates the bending of the entire delivery sheath 30 into the branch vessel. When the distal end of the delivery sheath 30 enters the branch vessel, the tube body located in the first segment 20 at the distal end of the delivery sheath 30 can bend, ensuring that the distal end of the delivery sheath 30 can slide from the main vessel 10 into the branch vessel, avoiding the inability of the distal end of the delivery sheath 30 to enter the branch vessel due to poor bending performance. In one embodiment, the first support structure 31 of the delivery sheath 30 is a braided mesh tube with a large axial inter-filament angle, and the second support structure 32 is a braided mesh tube with a smaller angle. The two can be directly connected, or the first support structure 31 and the second support structure 32 can be separated by a flexible segment 342. Furthermore, the first support structure 31 can be replaced with a spring tube with better bending performance, and the second support structure 32 can be replaced with a braided mesh tube with better anti-extension performance, thus improving both the support and mechanical transmission effects while simultaneously enhancing the bending effect at the distal end of the sheath. The second section of the delivery sheath 30 can incorporate single- or double-helical spiral yarns to improve the axial mechanical transmission performance of the delivery sheath 30; the pitch of the spiral yarns is adjustable. The second support structure 31 of the delivery sheath 30 can incorporate a single- or double-axially oriented yarn, giving the delivery sheath 30 a certain degree of bending directionality, reducing rebound bending during retraction, and improving the stability of vascular stent deployment.

[0086] In summary, in the delivery device of the present invention, the first tube segment is located at the distal end of the second tube segment. The first tube segment includes a first support structure, and the second tube segment includes a second support structure. The curvature of the first support structure is greater than that of the second support structure. This results in the first tube segment, located at the distal end of the delivery sheath, having better flexibility than the proximal tube segment, including the second tube segment, located near the distal end. This allows the distal tube segment to bend more easily, facilitating the entire delivery sheath's insertion into branch vessels.

[0087] Furthermore, the second support structure has a greater resistance to axial elongation than the first support structure, which gives the second pipe section at the far end of the delivery sheath good mechanical transmission properties, ensuring that the entire delivery sheath maintains good stability while meeting bending requirements.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A conveyor comprising a conveying sheath, the conveying sheath comprising an outer tube and a support tube disposed within the outer tube, characterized in that, The distal end of the support tube includes a first tube segment and a second tube segment along its length direction. The first tube segment is located at the distal end of the second tube segment. The first tube segment includes a first support structure, and the second tube segment includes a second support structure. Under the same force, the bending degree of the first support structure is greater than that of the second support structure. The second tube segment also includes a reinforcing structure disposed on the second support structure. The reinforcing structure is used to increase the elongation resistance of the second tube segment. The reinforcing structure includes at least one second reinforcing member, which extends along the axial direction of the second support structure and is located on one side of the second support structure. The second reinforcing member is used to guide the second support structure to bend toward the branch vessel.

2. The conveyor according to claim 1, characterized in that, The second support structure has greater resistance to axial elongation than the first support structure.

3. The conveyor according to claim 2, characterized in that, The proximal end of the first support structure is connected to the second support structure through a third support structure, or there is a gap between the first support structure and the second support structure.

4. The conveyor according to claim 1, characterized in that, The first support structure is a spiral structure or a braided mesh structure, and / or the second support structure is a spiral structure or a braided mesh structure.

5. The conveyor as claimed in claim 1, characterized in that: The reinforcing structure includes a plurality of first reinforcing members distributed along the axial direction, and the spacing between the plurality of adjacent first reinforcing members is equal.

6. The conveyor as described in claim 5, characterized in that: The spacing between adjacent first reinforcing members gradually decreases from the near end to the far end of the second support structure.

7. The conveyor as claimed in claim 1, characterized in that: The number of the second reinforcing members is multiple, and the multiple second reinforcing members are arranged circumferentially along the second support structure.

8. The conveyor as claimed in claim 1, characterized in that: The diameter of the second reinforcing member gradually decreases from the near end to the far end of the second support structure.

9. A support system, characterized in that: It includes a vascular stent and a delivery sheath as described in any one of claims 1-8, wherein the vascular stent is delivered to a desired location via the delivery device.

Images