Stent delivery system and stent system comprising same

Abstract

This invention relates to a stent delivery system and a stent system including the same. The stent delivery system includes a force transmission network centered at a pivot point at its distal end, used to decompose the force applied at the pivot point along the network. The force transmission network converges at its distal end near the pivot point to form a distal center. When radially restrained, the force transmission direction of the network is closer to the axial direction and towards the proximal end. When no external force restraint is applied, the force transmission network deforms, causing the force transmission direction to deviate further from the axial direction and towards the proximal end. By incorporating force transmission components, the stent delivery system effectively decomposes the force generated when the distal end of the delivery system contacts the vessel wall during stent implantation. Furthermore, the deformation of the force transmission network further offsets some or all of the decomposed force, thereby significantly reducing the force exerted by the stent delivery system on the vessel wall during stent implantation and reducing the risk of vessel wall puncture.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a stent delivery system and a stent system including the stent. Background Technology

[0002] Self-expanding stents are tubular implants widely used in interventional vascular treatments. They are typically delivered from the proximal external site (such as the radial or femoral artery) via a delivery system to the lesion site and expand radially within the lesion area to complete implantation. Relying on their self-expanding properties, self-expanding stents can expand and remain fixed within the vascular lumen after the delivery system is withdrawn, thereby guiding blood flow or maintaining vascular patency.

[0003] However, there are certain operational risks involved in the implantation of self-expanding stents. Particularly during microcatheter retraction, the stent undergoes axial shortening while expanding radially. In this situation, the distal end of the delivery system may extend beyond the distal end of the self-expanding stent, increasing the risk of distal perforation of the vessel wall, a risk that is particularly pronounced in complex, tortuous vessels.

[0004] At vascular bifurcation sites, lesions such as hemangiomas are often present, limiting the length of the normal vessel available for stent distal anchoring. In such cases, after the stent distally lands, the distal end of the delivery system can easily extend beyond the stent and touch the vessel wall. Especially in cases of thin vessel walls or narrow vascular lumens, contact by the distal end of the delivery system may cause vessel wall puncture or damage, further increasing surgical risks.

[0005] To reduce the risk of distal vessel wall perforation, shortening the delivery system might seem to mitigate this risk, but this approach can lead to insufficient pushing force, affecting the delivery performance and maneuverability of the self-expanding stent. Insufficient pushing force may result in inaccurate stent positioning or even failure to deploy correctly, thus impacting the implantation outcome.

[0006] Therefore, there is a need in the field to develop a stent delivery system that can reduce the risk of distal vessel wall perforation while ensuring sufficient delivery capability, in order to meet the clinical application needs in complex vascular lesions. Summary of the Invention

[0007] To address the shortcomings of existing technologies, one objective of this invention is to provide a support conveying system, wherein the conveying direction of the support is axial, the axial center is defined as the axis direction, and the intersection of the axis direction with any cross section perpendicular to the axis direction is the axis center point of the cross section.

[0008] The support delivery system includes a force transmission network centered on the axis point at a remote end, used to decompose the force applied at the axis point along the force transmission network;

[0009] The force transmission network converges at the far end near the axis point to form a far end center;

[0010] When the force transmission network is subjected to radial constraint, the force transmission direction of the force transmission network is closer to the axial direction;

[0011] The force transmission network deforms when there is no external force constraint, causing the force transmission direction of the force transmission network to deviate further from the axis direction.

[0012] The stent delivery system provided in this application features a force transmission network at its distal end. This network converges near its central axis to form a distal center, serving as the first point of contact for the delivery system. During stent implantation, when the distal end of the stent delivery system extends beyond the stent and contacts the vessel wall, the position of the distal center of the force transmission network is the first point of contact with the vessel wall. Therefore, the force transmission network is crucial for reducing the contact force between the distal end and the vessel wall during stent implantation, thereby lowering the risk of vessel wall puncture.

[0013] During stent delivery, the force transmission network provided in this application is subjected to radial restraint (typically due to the constraint of the microcatheter). In this state, the force transmission direction of the network is primarily along the axial direction, ensuring the stability and transmission of the pushing force. During stent implantation, as the microcatheter is withdrawn, the restraint of the force transmission network disappears, and the network deforms. During this process, the deformation of the network converts the vascular wall reaction force into a decomposed force deviating from the axial direction, and the deformation of the network partially or completely offsets this decomposed force.

[0014] In short, the stent delivery system provided in this application can effectively reduce the force acting on the blood vessel wall during stent implantation by setting up a force transmission network, thereby reducing the risk of puncture due to excessive force on the blood vessel wall. This is of great clinical significance, especially in the application of complex blood vessels or bifurcation sites.

[0015] Preferably, the force transmission network includes at least one circular array of lines arranged near the axis center; the distal ends of the array lines of the circular array converge at the axis center.

[0016] That is, the array elements of the line arrangement structure are lines (including straight lines, spirals, curves, wavy lines, Z-shaped lines, etc.) with the axis point as the endpoint, which are defined as array lines, and the array direction is a circular array with the axis point as the center.

[0017] The force transmission network may include one arrangement structure, or two or more arrangement structures, preferably two or more arrangement structures. When the force transmission network includes two or more arrangement structures, the array lines of different arrangement structures may intersect each other.

[0018] The arrangement structure can be understood as merely a restriction on the far end of the force transmission network.

[0019] Preferably, when the force transmission network is not constrained by external force, the angle between the force transmission direction at the distal end and the axial direction is 0° to 80° (excluding 0°), for example, 2°, 5°, 8°, 12°, 18°, 25°, 33°, 40°, 45°, 56°, 60°, 63°, 67°, 70°, 74°, 77°, 79°, etc., preferably 1° to 30°.

[0020] By setting the aforementioned angle, the force transmission network initially deviates from the axis when there is no radial restraint. On the one hand, this makes it easier for the force transmission network to deform (angle greater than 0°, especially greater than 1°) after being subjected to axial force, thereby counteracting the force. On the other hand, it ensures that the force transmission network has a large axial contraction space (e.g., less than 80°, especially less than 30°), thereby reducing pressure and damage to the blood vessel wall.

[0021] Typically, the direction of force transmission in a force transmission network is the tangent at the far end of the force transmission line.

[0022] In an optional specific embodiment, the force transmission network is formed by connecting elastic pillars or by overlapping elastic threads.

[0023] Preferably, the material of the force transmission network is a superelastic material and / or a shape memory material, preferably a nickel-titanium alloy.

[0024] The force transmission network is made of an elastic material, preferably a hyperelastic material and / or a shape memory material, so that it can deform when subjected to radial restraint and when there is no external force restraint.

[0025] Preferably, the elastic support connection is formed by laser engraving, chemical etching or electrical discharge machining.

[0026] Preferably, the size of the elastic support is 0.03 to 0.1 mm, such as 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, etc.

[0027] Preferably, the elastic threads are overlapped by weaving.

[0028] Preferably, the size of the elastic thread is 0.001 to 0.1 mm, such as 0.005 mm, 0.007 mm, 0.01 mm, 0.03 mm, 0.05 mm, 0.07 mm, 0.09 mm, etc.

[0029] This application does not impose specific limitations on the convergence method of the convergence end. Any known or new methods of convergence of array lines that can be obtained by those skilled in the art can be used in this application.

[0030] As an optional specific implementation, the force transmission network converges near the axis point to form a converging end. The converging end can be formed by any one or a combination of at least two of the following methods: convergence, welding, bonding, and integral molding.

[0031] Preferably, the convergence is achieved by converging the distal end of the force transmission network into a convergence component.

[0032] Preferably, the convergence component includes a rigid convergence component and / or a flexible convergence component, with a flexible convergence component being more preferred.

[0033] Preferably, the rigid converging component includes a rigid ring, and more preferably, the rigid ring is made of a radiopaque material.

[0034] Preferably, the flexible convergence component includes a flexible ring and a spiral winding structure, preferably a spiral coil.

[0035] In a preferred embodiment, the length of the converging end is less than or equal to the nominal diameter of the support conveyed by the support conveying system.

[0036] When a hemangioma is located at a vascular bifurcation, the distal end of the stent typically lands at the bifurcation, with the stent opening perpendicular to the vessel wall on the opposite side of the bifurcation. Due to the anatomical structure at the bifurcation, the space that the distal end of the delivery system can extend after stent deployment is extremely limited. The stent's distal landing point is located downstream of the hemangioma, where the vessel diameter is typically smaller than the diameter of the vessel at the hemangioma's location, approximately the nominal diameter of the stent to be implanted. Therefore, setting the length of the converging tip to be less than or equal to the nominal diameter of the delivered stent ensures that the converging tip will not penetrate the vessel wall on the opposite side of the bifurcation during the initial deployment phase. As the stent is gradually deployed and the constraint of the force transmission network gradually disappears, the converging tip gains more buffer space, further reducing the contact force on the vessel wall and avoiding the risk of perforation. This design not only ensures safe landing of the distal stent during initial deployment but also further reduces the possibility of vascular injury during stent deployment through the deformation and buffering effect of the force transmission network, thereby improving the safety and accuracy of stent implantation.

[0037] It should be noted that the stent delivery system provided in this application is not only suitable for bifurcation hemangiomas, but also for other types of hemangiomas. In these cases, because the stent has a larger anchoring space, the distal end of the delivery system can move freely within a wider range, reducing the risk of puncturing the blood vessel. Therefore, it is not necessary to limit the length of the converging tip as in the case of bifurcation hemangiomas. In this case, the length of the converging tip is not limited to being less than or equal to the nominal diameter of the stent delivered by the stent delivery system. The length of the converging tip can be appropriately adjusted according to specific treatment needs to further optimize the performance of the stent delivery system.

[0038] Preferably, the ratio of the length of the converging end to the length of the force transmission network under constrained state is 0:1 to 0.8:1, excluding 0:1, and preferably 0.1:1 to 0.6:1.

[0039] By setting the above ratio, the converging tip has a suitable length range relative to the force transmission network, thus balancing two needs: on the one hand, it allows the force transmission network sufficient length and space to effectively decompose the force on the converging tip, thereby reducing the risk of puncturing blood vessels; on the other hand, it improves the guidance of the converging tip, making the delivery system more stable in a restrained state, thereby improving the distal delivery and guidance performance of the stent delivery system; in addition, when the converging tip is made of radiopaque material, the appropriate length of the converging tip can also optimize the imaging effect.

[0040] In a preferred embodiment, the stent delivery system of this application includes a force transmission network disposed at the distal end. The force transmission network is preferably woven from 4 to 64 elastic threads intersecting in a mesh pattern. The Shore A hardness (D) of the elastic threads is preferably 30 to 50. The elastic threads converge at the distal end to form a converging end, and the ratio of the length of the converging end to the length of the force transmission network in its constrained state is preferably 0.1:1 to 0.6:1. The force transmission network expands in the unconstrained state, and the angle between the force transmission direction of the force transmission network (i.e., the extension direction of the elastic threads at the distal end) and the axial direction is 1 to 30°. The shape of the force transmission network in the unconstrained state can be achieved through a pre-designed configuration.

[0041] In the preferred embodiment described in this application, the length ratio of the converging end, the number of metal wires in the force transmission network, the Shore hardness D value, and the angle between the force transmission direction and the axial direction work together to enable the entire stent delivery system to maintain good pushability, stability, and guidance during stent delivery, and to more effectively reduce the risk of damage to the blood vessel wall during stent deployment and implantation.

[0042] Specifically, a suitable convergence tip ratio (0.1:1 to 0.6:1) ensures that the stent delivery system has a convergence tip of a certain length at the distal end. During delivery, the convergence tip can converge the dispersed conductive forces of the force transmission network, resulting in better performance in terms of pushability, stability, and guidance of the stent delivery system. The appropriate hardness and number of the force transmission network wires, as well as the angle between the force transmission direction and the axial direction, allow for easier deformation during stent deployment and implantation, offsetting the forces on the convergence tip and reducing damage to the vessel wall. At the same time, during stent delivery, the convergence tip can maintain good axial thrust inside the delivery catheter.

[0043] In an optional specific implementation, the distal end of the converging end has a convex curved surface, such as an arc surface or a spherical cap surface.

[0044] The converging end is designed with a convex curved surface to ensure that the distal end of the delivery system makes smoother and more uniform contact with the blood vessel wall, thereby reducing local pressure and irritation to the blood vessel wall, meeting the requirements for blood vessel wall protection, and effectively reducing the risk of the distal end of the delivery system puncturing the blood vessel wall.

[0045] Preferably, a buffer end is provided at the far end of the converging end, and the Shore hardness D of the buffer end is 50 to 80, such as 51, 55, 58, 63, 67, 73, etc.

[0046] Preferably, the material of the buffer end is a biocompatible polymer adhesive or solder paste, and more preferably includes UV-curable adhesive, epoxy resin adhesive or other polymer adhesives.

[0047] The buffer tip is used to cover any sharp edges that may exist at the converging tip, thereby effectively avoiding or minimizing damage to the blood vessel wall. By selecting an appropriate Shore hardness range, the buffer tip has good flexibility and elasticity, further reducing local pressure and irritation to the blood vessel wall, effectively minimizing damage and impact on the blood vessel wall, and improving safety during the implantation process.

[0048] In one optional embodiment, the force transmission network includes at least one circular array of lines arranged near the axis; the distal ends of the array lines of the circular array converge at the axis; the extension of the array lines toward the proximal ends is either regularly arranged or irregularly arranged.

[0049] Preferably, the force transmission network converges into a proximal convergence portion at its proximal end.

[0050] Preferably, the proximal convergence portion is positioned along the axial direction.

[0051] The proximal convergence into a proximal constriction facilitates the withdrawal of the delivery system into the microcatheter after stent implantation, and then its removal from the body.

[0052] Preferably, the stent delivery system further includes a pushing component connected to the proximal end of the force transmission network.

[0053] The pushing component is used to transmit the pushing force to the force transmission network.

[0054] Preferably, the pushing component includes any one or a combination of at least two of the following: a pushing guide wire and an axially extending deformable component;

[0055] Preferably, the axially extending deformable component includes any one or a combination of at least two of the following: a segmented expansion component and a helical wire structure.

[0056] The second objective of this application is to provide a support system, comprising:

[0057] One of the objectives is the support delivery system described above;

[0058] A support, which is fitted onto a support conveying system described in one of the purposes in a conveying state, with the distal end of the support located outside the force transmission network.

[0059] The distal end of the support delivery system is positioned as far as possible at the distal end of the support to provide better pushing performance.

[0060] Preferably, the distal end of the bracket is located on the outside near the distal end of the force transmission network.

[0061] Compared with the prior art, this application has the following beneficial effects:

[0062] This application provides a stent delivery system that, by incorporating a force transmission component, effectively decomposes the force generated when the distal end of the delivery system contacts the blood vessel wall during stent implantation. Through the deformation of the force transmission network, some or all of the decomposed force is further offset, thereby significantly reducing the force exerted by the stent delivery system on the blood vessel wall during stent implantation and reducing the risk of blood vessel wall puncture. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the force transmission network 200 of the support conveying system provided in Example 1 from the perspective of the axis point.

[0064] Figure 2 A schematic diagram of the support conveying system provided in Example 1;

[0065] Figure 3 This is a schematic diagram of the force transmission network 200 of the support conveying system provided in Embodiment 2 from the perspective of the axis point.

[0066] Figure 4 This is a schematic diagram of the support conveying system provided in Example 2;

[0067] Figure 5 This is a structural schematic diagram of the force transmission network 200 of the support conveying system provided in Example 3 from the perspective of the axis point. Detailed Implementation

[0068] The technical solution of the present invention will be further explained and described below with reference to specific embodiments. However, it should be noted that the specific embodiments are only a specific implementation and explanation of the essence of the technical solution of the present invention, and should not be construed as a limitation on the scope of protection of the present invention.

[0069] In the description of this invention, it should be understood that the terms "distal" and "proximal" should be understood as referring to the end viewed from the surgeon's perspective; "distal" is the end furthest from the surgeon, while "proximal" is the end closest to the surgeon. The term "axial" refers to the direction of stent delivery, "axial direction" refers to the axial extension direction, and "center point" is the intersection of the axial direction and any cross-section perpendicular to the axial direction.

[0070] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0071] Example 1

[0072] like Figures 1-2 ( Figure 1 This is a structural schematic diagram of the force transmission network 200 of the support conveying system provided in Example 1 from the perspective of the axis point. Figure 2 As shown in the structural schematic diagram of the stent delivery system provided in Embodiment 1, a stent delivery system includes a push guide wire 100 (1.5m in length) and a force transmission network 200 disposed at the distal end of the push guide wire;

[0073] The force transmission network 200 includes six straight array lines 202 (3 mm in length), with the distal end bound by a spiral coil to form a converging end 203 (2.3 mm in length), and the proximal end converging within the developing ring 300. Both the proximal and distal ends of the force transmission network 200 are positioned along the axial direction. The array lines 202 are made of nitinol alloy wire (0.046 mm in diameter, Shore hardness D of 60). The force transmission network 200 is heat-set to form a structure with a large internal space in the middle and constricted ends, thus obtaining the shape of the force transmission network 200.

[0074] The support conveying system can convey supports of any nominal diameter, preferably supports with a nominal diameter of 2.3 to 5.6 mm. The ratio of the length of the converging end to the length of the force transmission network under constrained state is 0.77:1.

[0075] The distal force of the stent delivery system provided in Example 1 was tested using a full-module push-pull force meter and a distal force sensor. The test method involved measuring the proximal push force and distal force values ​​when the proximal end was pushed 2 mm. The results showed that the proximal push force ranged from 40 to 100 mN, and the distal force ranged from 10 to 17 mN. It can be seen that the stent delivery system provided in this application effectively reduces the distal force value and decreases damage to blood vessels.

[0076] In other embodiments, the length of the converging end 203 may be less than or equal to the nominal diameter of the support to be transported.

[0077] In other schemes, the angle between the extension direction of the elastic thread at the distal end and the axial direction can be selected to be any angle from 0 to 80° (excluding 0°); the ratio of the length of the converging end to the length of the force transmission network under the bound state can also be any value in the range of 0:1 to 0.8:1 (excluding 0:1).

[0078] In a preferred embodiment, a buffer end 2031 is provided at the distal end of the converging end 203. The buffer end 2031 is formed by shaping a convex surface from a biocompatible polymer adhesive, and the Shore hardness D of the buffer end 2031 is 50 to 80.

[0079] The support conveying system provided in Example 1 achieves an angle α of 24° between the array line 202 and the axial direction when there is no external force constraint. This is achieved through heat setting, that is, the array line 202 is shaped to have an angle of 24° with the axial direction through heat setting.

[0080] Example 2

[0081] like Figures 3-4 ( Figure 3 This is a structural schematic diagram of the force transmission network 200 of the support conveying system provided in Embodiment 2 from the perspective of the axis point. Figure 4 As shown in the structural schematic diagram of the stent delivery system provided in Embodiment 2, a stent delivery system includes a push guide wire 100 (1.5m in length) and a force transmission network 200 disposed at the distal end of the push guide wire. The force transmission network 200 includes a first arrangement structure 210 and a second arrangement structure 220.

[0082] The first arrangement structure 210 includes four first curved array lines 212 (5 mm in length), and the second arrangement structure 220 includes four second curved array lines 222 (5 mm in length). The distal ends of the first curved array lines 212 and the second curved array lines 222 are bound together and converged at a converging end 203 (1.5 mm in length) by a spiral coil. The proximal ends of the first curved array lines 212 and the second curved array lines 222 are bound together and converged within the developing ring 300. The first curved array lines 212 and the second curved array lines 222 are interwoven into a grid pattern.

[0083] The first curved array line 212 and the second curved array line 222 are made of nickel-titanium alloy wire (wire diameter 0.046 mm, Shore hardness D 60). The force transmission network 200 is heat-set into a structure with a large internal space in the middle and tightened at both ends to obtain the shape of the force transmission network.

[0084] The support conveying system can convey supports of any nominal diameter, preferably supports with a nominal diameter of 1.5 to 5.6 mm. The angle between the extension direction of the array line at the distal end and the axial direction is 10°, and the ratio of the length of the converging end to the length of the force transmission network under constrained state is 0.30:1.

[0085] The distal force of the stent delivery system provided in Example 2 was tested using a full-module push-pull force meter and a distal force sensor. The test method involved measuring the proximal push force and distal force values ​​when the proximal end was pushed 2 mm. The results showed that the proximal push force was 45–60 mN, and the distal force was 10–13 mN. It can be seen that the stent delivery system provided in this application effectively reduces the distal force value, reduces damage to blood vessels, and significantly reduces the fluctuation range of its distal push force and distal force value, exhibiting a more stable pushing effect.

[0086] In an optional embodiment, the push guide wire 100 includes a proximal push guide wire and an axially extending deformation member disposed at the distal end of the push guide wire. The proximal end of the force transmission network 200 is connected to the distal end of the axially extending deformation member. The axially extending deformation member can be configured as a segmental convergence member, achieved by convergence of a pre-shaped tubular structure. The tubular structure can be obtained by pre-shaping and convergence of both ends of a metal tube after braiding or laser engraving. In an optional embodiment, the array lines of the force transmission network can be extended and braided based on the above dimensions.

[0087] In a preferred embodiment, the length of the converging end 203 is less than or equal to the nominal diameter of the support to be transported.

[0088] In other schemes, the angle between the extension direction of the array line at the far end and the axial direction can be selected to be any angle from 0 to 80° (excluding 0°); the ratio of the length of the converging end to the length of the force transmission network under the bound state can also be any value in the range of 0:1 to 0.8:1 (excluding 0:1).

[0089] In a preferred embodiment, the distal end of the converging end 203 is provided with a buffer end 2031, which is formed by shaping a convex surface from a biocompatible polymer. The buffer end 2031 has a Shore hardness D of 50 to 80 and a tensile strength of 2% to 150%.

[0090] Example 3

[0091] like Figure 5 ( Figure 5 As shown in the schematic diagram of the force transmission network 200 of the stent delivery system provided in Embodiment 3 from the angle of the axis point, a stent delivery system includes a push guide wire (1.5m in length, not shown in the figure) and a force transmission network 200 disposed at the distal end of the push guide wire;

[0092] The force transmission network 200 includes five straight array lines 202 (7 mm in length), with the distal end bound by a spiral coil to form a converging end 203 (1.05 mm in length), and the proximal end converging within the developing ring 300. Both the proximal and distal ends of the force transmission network 200 are positioned along the axial direction. The array lines 202 are made of nitinol alloy wire (0.046 mm in diameter, Shore hardness D of 60). The force transmission network 200 is heat-set to form a structure with a large internal space in the middle and constricted ends, thus obtaining the shape of the force transmission network 200.

[0093] The support conveying system can convey supports of any nominal diameter, preferably supports with a nominal diameter of 1.05 to 5.6 mm. The angle between the extension direction of the array line at the distal end and the axial direction is 80°, and the ratio of the length of the converging end to the length of the force transmission network under constrained state is 0.15:1.

[0094] The distal force of the stent delivery system provided in Example 3 was tested using a full-module push-pull force meter and a distal force sensor. The test method involved measuring the proximal push force and distal force values ​​when the proximal end was pushed 2 mm. The results showed that the maximum proximal push force was 40–100 mN, and the maximum distal force was 9–18 mN. The stent delivery system provided in this application effectively reduces the distal force value and decreases damage to blood vessels.

[0095] In other embodiments, the length of the converging end 203 may be less than or equal to the nominal diameter of the support to be transported.

[0096] In other schemes, the angle between the extension direction of the array line at the far end and the axial direction can be selected to be any angle from 0 to 80° (excluding 0°); the ratio of the length of the converging end to the length of the force transmission network under the bound state can also be any value in the range of 0:1 to 0.8:1 (excluding 0:1).

[0097] In a preferred embodiment, the distal end of the converging end 203 is provided with a buffer end, which is formed by shaping a convex surface from a biocompatible polymer adhesive, and the Shore hardness D of the buffer end is 50 to 80.

[0098] The support conveying system provided in Example 1 achieves an 80° angle between the array line 202 and the axial direction when there is no external force constraint. This is achieved through heat setting, that is, the array line 202 is shaped to have an 80° angle with the axial direction through heat setting.

[0099] For comparison, a full-module push-back force meter and a distal force sensor were used to test the distal force of the stent delivery system provided by the 1.6m delivery guidewire. The test method was to measure the proximal push force and distal force when the proximal end was pushed 2mm. The results showed that the maximum proximal push force was 140–170 mN, and the maximum distal force was 48–90 mN. It can be seen that the distal force value is significantly higher when relying solely on the guidewire for stent delivery, which increases the risk of vascular puncture.

[0100] The stent delivery system described in this application is used in the treatment of bifurcation hemangiomas as follows:

[0101] (1) The stent 900 is held against the force transmission network 200 at the distal end of the stent delivery system and is loaded inside the microcatheter 800; the push guide wire 100 of the stent delivery system extends proximally outside the body;

[0102] (2) The guide wire 100 of the stent delivery system is pushed to the hemangioma lesion. After the distal end of the stent 900 reaches the stent anchoring point (normal blood vessel) at the distal end of the lesion, the microcatheter 800 is withdrawn. The stent 900 expands radially, and the force transmission network 200 undergoes radial expansion deformation. However, since the radial expansion of the force transmission network 200 is smaller than the radial expansion size of the stent 900, the distal end of the stent delivery system is likely to extend beyond the distal end of the stent 900 and approach the downstream blood vessel wall of the bifurcation hemangioma. Since the force transmission network 200 is provided with several array lines that deviate from the axial direction, the force generated by approaching is decomposed into axial force and deviated axial force, which reduces the damage to the blood vessel wall. At the same time, the deformation of the array lines also cancels out the corresponding force, further reducing the damage to the blood vessel wall.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A stent delivery system, characterized by, The conveying direction of the bracket is axial, the axial center is defined as the axis direction, and the intersection of the axis direction and any cross section perpendicular to the axis direction is the axis center point of the cross section. The support delivery system includes a force transmission network centered on the axis point at a remote end, used to decompose the force applied at the axis point along the force transmission network; The force transmission network converges at the far end near the axis point to form a far end center; The force transmission direction of the force transmission network is closer to the axial direction and towards the proximal end when subjected to radial restraint; When the force transmission network is not restrained by external force, it deforms, causing the force transmission direction of the force transmission network to deviate further from the axis direction and move towards the proximal side.

2. The stent delivery system of claim 1, wherein, The force transmission network includes at least one circular array of lines arranged near the axis; the distal ends of the array lines of the circular array converge at the axis. Preferably, when the force transmission network is not constrained by external force, the angle between the force transmission direction at the distal end of the force transmission network and the axial direction is 0 to 80°, excluding 0°, and preferably 1 to 30°.

3. The stent delivery system of claim 1 or 2, wherein, The force transmission network is formed by connecting elastic pillars or by overlapping elastic threads; Preferably, the material of the force transmission network is a superelastic material and / or a shape memory material, preferably a nickel-titanium alloy; Preferably, the elastic support connection is formed by laser engraving, chemical etching or electrical discharge machining; Preferably, the size of the elastic support is 0.03 to 0.1 mm; Preferably, the elastic threads are overlapped by weaving; Preferably, the size of the elastic thread is 0.001 to 0.1 mm.

4. Stent delivery system according to one of claims 1 to 3, characterized in that The force transmission network converges near the axis point to form a converging end. The converging end can be formed by any one or a combination of at least two of the following methods: convergence, welding, bonding, and integral molding. Preferably, the convergence is achieved by bringing the distal end of the force transmission network into a convergence component; Preferably, the convergence component includes a rigid convergence component and / or a flexible convergence component, with a flexible convergence component being more preferred; Preferably, the rigid convergence component includes a rigid ring, and more preferably, the rigid ring is made of a non-transparent material; Preferably, the flexible convergence component includes a flexible ring and a spiral winding structure, preferably a spiral coil.

5. The support conveying system as described in claim 4, characterized in that, The length of the converging end is less than or equal to the nominal diameter of the support conveyed by the support conveying system; Preferably, the ratio of the length of the converging end to the length of the force transmission network under constrained state is 0:1 to 0.8:1, excluding 0:1, and preferably 0.1:1 to 0.6:

1.

6. The support conveying system as described in claim 4 or 5, characterized in that, The distal end of the converging end has a convex curved surface; Preferably, a buffer end is provided at the distal end of the converging end, and the Shore hardness D of the buffer end is 50 to 80; Preferably, the material of the buffer end is a biocompatible polymer adhesive or solder paste, and more preferably includes UV-curable adhesive, epoxy resin adhesive or other polymer adhesives.

7. The support conveying system as described in any one of claims 1 to 6, characterized in that, The force transmission network includes at least one circular array of lines arranged near the axis; the array lines of the circular array converge at the axis at their distal ends; the extension of the array lines toward the proximal ends is either regularly arranged or irregularly arranged. Preferably, the force transmission network converges into a proximal convergence portion at its proximal end; Preferably, the proximal convergence portion is positioned along the axial direction.

8. The support conveying system as described in any one of claims 1 to 7, characterized in that, The stent delivery system also includes a pushing component connected to the proximal end of the force transmission network; Preferably, the pushing component includes any one or a combination of at least two of the following: a pushing guide wire and an axially extending deformable component; Preferably, the axially extending deformable component includes any one or a combination of at least two of the following: a segmented expansion component and a helical wire structure.

9. A support system, characterized in that, The support system includes: The support conveying system according to any one of claims 1 to 8; A support, which is fitted onto the support conveying system according to any one of claims 1 to 8 in the conveying state, and the distal end of the support is disposed outside the force transmission network.

10. The support system as claimed in claim 9, characterized in that, The distal end of the bracket is positioned on the outside near the distal end of the force transmission network.

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