An iliac vein stent and its system

Abstract

This invention provides an iliac vein stent and its system. The iliac vein stent includes a main stent, an embedded branch, and a second branch. The main stent includes a main body and a first branch connected to the distal end of the main body. The embedded branch is folded and shaped and then placed within the main body, with a portion of its outer wall fixedly connected to the inner wall of the main stent. Compared to its natural state, the minimum distance between the embedded branch and the center of the main body is increased in the folded and shaped state. The second branch is embedded in the embedded branch and connected to the main stent. Because the embedded branch is folded and shaped and placed within the main body, the elastic recovery force of the embedded branch in the folded and shaped state is small or even negligible. When the compressed iliac vein stent is located within the sheath, the compressive and frictional forces between the embedded branch and the inner sheath core are reduced, effectively mitigating damage to the embedded branch from the inner sheath core.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an iliac vein stent and its system. Background Technology

[0002] Catheter-based interventional treatment of cardiovascular diseases is a common approach. Specifically, it involves placing various materials and instruments into the heart, arteries, and veins via catheters to treat cardiovascular conditions.

[0003] For example, the iliac vein, as an important blood vessel for blood return from the lower limbs and pelvis to the heart, is easily compressed due to its specific anatomical structure, leading to blood flow obstruction and other complications. The compressed segment of the iliac vein, as the compressed portion of the iliac vein, carries the risk of localized luminal stenosis and requires interventional surgical treatment.

[0004] See Figure 1 As shown, existing iliac artery bifurcation stent assemblies generally include a main stent 1 and an embedded stent 2. During installation, the inner sheath core 3 passes through the main stent 1, and the outer periphery of the inner sheath core 3 contacts the embedded stent 2. Then, the entire iliac artery bifurcation stent assembly is compressed within the sheath. During compression, because the embedded stent 2 is made of elastic nickel-titanium wire, the elastic nickel-titanium wire of the embedded stent 2 is under compressed stress. The inner sheath core 3 contacts and presses against the embedded stent 2, generating a large compressive force. When the compressed iliac artery bifurcation stent assembly moves within the sheath, the embedded stent 2 and the inner sheath core 3 will press against each other and rub against each other, causing damage to the embedded stent 2. Summary of the Invention

[0005] To address the aforementioned shortcomings, this invention provides an iliac vein stent and its system. The iliac vein stent includes: a main stent comprising a main body portion and a first branch connected to the distal end of the main body portion; an embedded branch, which is folded and shaped and disposed within the main body portion, with a portion of the outer wall of the embedded branch fixedly connected to the inner wall of the main stent; compared to its natural state, the minimum distance between the embedded branch and the center of the main body portion is increased in the folded and shaped state; and a second branch, which can be embedded in the embedded branch and connected to the main stent.

[0006] Furthermore, in its natural state, the cross-section of the embedded branch is annular; in its folded and shaped state, at least a portion of the inner walls of the embedded branch are brought close to each other, resulting in a non-annular cross-sectional shape for the embedded branch.

[0007] Furthermore, in the folded and shaped state, the embedded branches bend and fold to form an arc shape.

[0008] Furthermore, in the folded and shaped state, the two free ends of the bow-shaped embedded branch are further bent toward each other to form a C-shape.

[0009] Furthermore, the embedded branch includes a mesh reinforcement layer and a coating layer, wherein the mesh reinforcement layer is disposed on the coating layer.

[0010] Furthermore, the mesh reinforcement layer includes a plurality of first-direction reinforcing filaments and a plurality of second-direction reinforcing filaments, the first-direction reinforcing filaments and the second-direction reinforcing filaments overlapping each other to form a mesh reinforcement layer, and the coating layer covers one or both sides of the mesh reinforcement layer.

[0011] Furthermore, the mesh reinforcement layer and the coating layer are composed of one or more of polylactic acid, polycaprolactone, and polycarbonate.

[0012] The present invention also relates to an iliac vein stent system, comprising the aforementioned iliac vein stent and a delivery device, the delivery device comprising: a handle; a sheath, the proximal side of which is connected to the handle; an inner sheath core, slidably inserted in the sheath and the proximal side of which is connected to the handle; and an outer sheath core, sleeved outside the inner sheath core and located within the sheath, the proximal side of which is fixedly connected to the handle; the iliac vein stent is sleeved on the inner sheath core and located within the sheath, and an expansion device is provided in the embedded branch, the expansion device being able to expand the embedded branch from a folded and shaped state to a natural state.

[0013] Furthermore, it also includes a connecting tube, wherein a through channel is provided on the wall of the outer sheath core, the through channel extends axially from the proximal end of the outer sheath core to the distal end face of the outer sheath core, the distal end of the connecting tube passes through the through channel and communicates with the expansion device, and the proximal end of the connecting tube extends out from the through channel and communicates with the outside of the handle.

[0014] Furthermore, a pipe connector is movably connected to the handle, and the proximal end of the connecting pipe is fixedly connected to and communicates with the pipe connector.

[0015] The iliac vein stent and system provided in this embodiment of the invention have an embedded branch that is folded and shaped and then placed inside the main body. The elastic recovery force of the embedded branch in the folded and shaped state is small or even negligible. When the compressed iliac vein stent moves in the sheath or when the iliac vein stent is located in the sheath, the compressive force and friction force generated by the mutual compression between the embedded branch and the inner sheath core can be minimized. Thus, damage to the embedded branch or the inner sheath core can be effectively reduced during the insertion or removal of the iliac vein stent from the sheath.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the embodiments of the present invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of an iliac artery bifurcation stent assembly in the background art;

[0019] Figure 2 This is a schematic diagram of the iliac vein stent provided in an embodiment of the present invention;

[0020] Figure 3 This is a diagram of an embedded branch in a folded and shaped state according to an embodiment of the present invention;

[0021] Figure 4(A) is a schematic diagram of the embedded branch in its natural state according to an embodiment of the present invention;

[0022] Figure 4(B) is a schematic diagram of the iliac vein stent with embedded branches in a natural state according to an embodiment of the present invention.

[0023] Figure 5 This is a partial structural schematic diagram of an iliac vein stent system provided in an embodiment of the present invention, which shows the inner sheath core, sheath tube, and embedded branches;

[0024] Figure 6 This is a diagram showing another folding and shaping state of the embedded branch provided in an embodiment of the present invention;

[0025] Figure 7 This is a schematic diagram of the installation of the embedded branch in the sheath when it is in a folded and shaped state, according to an embodiment of the present invention;

[0026] Figure 8 This is a schematic diagram of the structure of the first molding die provided in an embodiment of the present invention;

[0027] Figure 9 This is a partial structural schematic diagram of the first molding die provided in an embodiment of the present invention;

[0028] Figure 10 This is a schematic diagram of the structure of the second shaping mold provided in an embodiment of the present invention;

[0029] Figure 11 This is a partial structural schematic diagram of the second shaping mold provided in an embodiment of the present invention;

[0030] Figure 12This is a schematic diagram of the overall structure of the embedded branch provided in an embodiment of the present invention;

[0031] Figure 13 This is a schematic diagram of a multi-layer structure with embedded branches provided in an embodiment of the present invention;

[0032] Figure 14 This is a schematic diagram illustrating the fabrication of an embedded branch according to an embodiment of the present invention;

[0033] Figure 15 This is a schematic diagram illustrating the fabrication of another embedded branch provided in an embodiment of the present invention;

[0034] Figure 16 This is a schematic diagram of the iliac vein stent system provided in an embodiment of the present invention;

[0035] Figure 17 This is a partial structural schematic diagram of an iliac vein stent system provided in an embodiment of the present invention;

[0036] Figure 18 This is a cross-sectional view of the outer sheath provided in an embodiment of the present invention;

[0037] Figure 19 This is a partial structural schematic diagram of an iliac vein stent system provided in an embodiment of the present invention, wherein the expansion device is close to the through channel;

[0038] Figure 20 This is a schematic diagram of the iliac vein stent system provided in an embodiment of the present invention;

[0039] Explanation of reference numerals in the attached figures:

[0040] 100. Iliac vein stent;

[0041] 10. Main support frame; 11. Main body; 111. First opening; 112. Second opening; 12. First branch;

[0042] 20. Embedded branch; 21. Mesh reinforcement layer; 211. First direction reinforcing filament; 212. Second direction reinforcing filament; 22. Coating layer; 23. First intermediate layer; 24. Second intermediate layer; 25. Internal channel;

[0043] 30. Second branch;

[0044] 200. Conveyor; 201. Inner sheath core; 202. Sheath tube; 203. Handle; 204. Outer sheath core; 2041. Through channel; 2042. Sheath core channel;

[0045] 300, Expansion device; 400, Connecting pipe; 500, Pipe fitting;

[0046] 1000a, First shaping mold; 1001, First pressing fixture; 1002, First placement fixture; 1000b, Second shaping mold; 1003, Second pressing fixture; 1004, Second placement fixture;

[0047] 2001, Spinneret; 2002, Rotary receiving shaft; 3001, Tooling; 3002, Coating liquid. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0050] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0051] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0052] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0053] For ease of description, the terms "proximal" and "distal" are used here as conventional terms in the field of interventional medicine. "Distal" refers to the end furthest from the operator during the procedure, while "proximal" refers to the end closest to the operator. The axial direction of the occlusion body or iliac vein stent refers to the direction parallel to the line connecting the distal and proximal centers of the interventional medical device; the radial direction of the occlusion body or iliac vein stent refers to the direction perpendicular to the aforementioned axial direction.

[0054] The natural state of medical devices such as embedded branches refers to the natural unfolding state of the medical device when it is not subjected to external force.

[0055] Please see Figures 2 to 4(A) This invention provides an iliac vein stent 100, including a main stent 10, an embedded branch 20, and a second branch 30. The main stent 10 includes a main body 11 and a first branch 12 connected to the distal end of the main body 11. The embedded branch 20 is folded and shaped and disposed within the main body 11, with a portion of its outer wall fixedly connected to the inner wall of the main stent 10. Compared to its natural state, the minimum distance between the embedded branch 20 and the center of the main body 11 is increased in the folded and shaped state. The second branch 30 is embedded in the embedded branch 20 and connected to the main stent 10. Exemplarily, the minimum distance between the embedded branch 20 and the center of the main body 11 is shown as D1 in Figure 4(B). D1 in the folded and shaped state is greater than D1 in the natural state. Exemplarily, the maximum distance between the embedded branch 20 and the center of the main body 11 is shown as D2 in Figure 4(B).

[0056] Compared to embedded branches made of highly elastic materials and naturally positioned within the main stent, the embedded branch 20 in this embodiment is folded and shaped before being positioned within the main body 11. The elastic recovery force of the embedded branch 20 in its folded and shaped state is small, even negligible. When the iliac vein stent 100 is located within the sheath 202, the compressive force between the embedded branch 20 and the inner sheath core 201 is small, or even nonexistent. When the compressed iliac vein stent 100 moves within the sheath 202, the friction between the embedded branch 20 and the inner sheath core 201 is minimized. Therefore, during the insertion or removal of the iliac vein stent 100 from the sheath, damage to the embedded branch 20 from the inner sheath core 201 is effectively reduced, thus protecting the embedded branch 20. After the iliac vein stent 100 is removed from the sheath, the embedded branch 20 can switch from its folded and shaped state to its natural state, allowing it to be used to connect to the second branch 30.

[0057] Please see Figure 2For example, the main body 11 includes a first opening 111, an embedded branch 20 is fixedly connected to the inner wall of the main body support 10, and a second branch 30 can be embedded in the embedded branch 20 through the first opening 111. The angle between the end face of the first opening 111 and the cross-section is in the range of [0°, 40°], so as to better conform to the vascular structure and better connect with the second branch 30.

[0058] Please see Figure 2 The main body 11 includes a second opening 112, which is located at one end of the main body 11, along with the first opening 111. The mesh density in different regions of the main body 11 can be the same or different. Different mesh densities in different regions of the main body 11 allow for designs with varying radial support forces. For example, the mesh density in the region of the main body 11 near the first opening 111 can be denser to provide strong radial support. Conversely, the mesh density in the region of the main body 11 near the second opening 112 can be sparser to provide weak radial support, thereby reducing stimulation of the inferior vena cava, preventing intimal hyperplasia, and preventing further restenosis.

[0059] Exemplarily, in its natural state, the angle between the end face of the embedded branch 20 near the first opening 111 and the cross-section ranges from [0° to 40°]. This cross-section is perpendicular to the axis of the iliac vein stent 100 to better conform to the vascular structure and to better connect with the second branch 30. Exemplarily, in its natural state, the end face of the first opening 111 of the main body 11 is approximately parallel to the end face of the second branch 30 near the first opening 111 to facilitate better embedding of the second branch 30 into the embedded branch 20.

[0060] In some embodiments, in the natural state, the cross-section of the embedded branch 20 is annular, as shown in FIG4(A); in the folded and shaped state, at least a portion of the inner walls of the embedded branch 20 are brought close to each other, such that the cross-sectional shape of the embedded branch 20 is non-annular, as shown in FIG4(A). Figure 3 As shown. This helps to reduce the radial dimension of the embedded branch 20 in the folded and shaped state, which in turn helps to reduce the radial dimension of the iliac vein stent 100 when it is inserted into the sheath 202, making it easier for the iliac vein stent 100 to be inserted into a smaller sheath 202, facilitating delivery and reducing damage to the human body.

[0061] Please see Figure 3In some embodiments, in the folded and shaped state, the inner walls of the embedded branches 20 are bent into an arc shape after being pressed together. Thus, the embedded branches 20, after being folded and shaped and placed within the main body 11, reduce the surface area of ​​the embedded branches 20, thereby reducing the contact area between the embedded branches 20 and the inner sheath core 201 during the insertion of the iliac vein stent 100 into the sheath. Consequently, when the iliac vein stent 100, inserted into the sheath tube 202, moves within the sheath tube 202, the degree of mutual compression and friction between the folded and shaped embedded branches 20 and the inner sheath core 201 is reduced, thereby minimizing the degree of damage to the embedded branches 20 during the movement of the iliac vein stent 100.

[0062] Please see Figure 6 and Figure 7 In some embodiments, in the folded and shaped state, the two free ends of the bow-shaped embedded branch 20 are further bent towards each other to form a C-shape. Thus, during the insertion of the iliac vein stent 100 into the sheath, the area of ​​the embedded branch 20 that contacts the inner sheath core 201 is the end region of the free end of the C-shaped embedded branch 20, eliminating the need for the embedded branch 20 to make face-to-face contact with the inner sheath core 201, effectively reducing the contact area between the embedded branch 20 and the inner sheath core 201 during the insertion of the iliac vein stent 100. When the iliac vein stent 100 moves within the sheath 202, the degree of mutual compression and friction between the embedded branch 20 in the folded and shaped state and the inner sheath core 201 can be minimized, thereby minimizing the degree of damage to the embedded branch 20 during the insertion of the iliac vein stent 100 into the sheath. In other embodiments, the shape of the embedded branch 20 in the folded and shaped state can also be other shapes.

[0063] For example, such as Figure 8 and Figure 9 After the embedded branch 20 in its natural state is completed, it can be shaped using the first molding mold 1000a. The first molding mold 1000a includes a first pressing fixture 1001 and a first placing fixture 1002. The first pressing fixture 1001 and / or the first placing fixture 1002 are hollow, allowing for appropriate plasticizing temperatures (60℃-120℃) to be provided by heating the liquid inside (water, oil, etc.). During the one-time molding of the embedded branch 20, the embedded branch 20 is placed in the groove of the first placing fixture 1002. The first pressing fixture 1001 presses down at a certain speed (e.g., 100mm / s-500mm / s) while maintaining a pressure of 0.1MPa-0.2MPa for 3-10 seconds. Then, the first pressing fixture 1001 is lifted, thus completing the first molding. The shape of the embedded branch 20 after the first molding is as follows: Figure 9 As shown. Similarly, please refer to... Figure 10 and Figure 11Next, the embedded branch 20, which has completed the first shaping, undergoes a second shaping process using a second shaping mold 1000b. The second shaping mold 1000b includes a second pressing fixture 1003 and a second placing fixture 1004. The embedded branch 20, having completed the first shaping, is placed in the groove of the second placing fixture 1004. The second pressing fixture 1003 is pressed down at a certain speed (e.g., 50mm / s-100mm / s) while maintaining a pressure of 0.1MPa-0.2MPa for 1-2 seconds. Then, the second pressing fixture 1003 is lifted, thus completing the second shaping. The shape of the embedded branch 20 after the second shaping is as follows: Figure 11 As shown.

[0064] Please see Figure 12 In some embodiments, the embedded branch 20 includes a mesh reinforcement layer 21 and a coating layer 22, which are integrally formed. This simplifies the fabrication of the embedded branch 20 and ensures a reliable connection between the mesh reinforcement layer 21 and the coating layer 22. In other embodiments, the mesh reinforcement layer 21 and the coating layer 22 can be separately disposed. The coating layer 22 can be disposed only on the inner side of the mesh reinforcement layer 21, or it can be disposed on both the inner and outer sides of the mesh reinforcement layer 21. In other embodiments, the mesh reinforcement layer 21 can be omitted.

[0065] Please see Figure 12 In some embodiments, the mesh reinforcement layer 21 includes a plurality of first-direction reinforcing wires 211 and a plurality of second-direction reinforcing wires 212, which overlap to form the mesh reinforcement layer 21. A coating layer 22 covers one or both sides of the mesh reinforcement layer 21. The first-direction reinforcing wires 211 and the second-direction reinforcing wires 212 can reinforce the embedded branches 20 from two directions, effectively improving the mechanical strength of the embedded branches 20.

[0066] The mesh reinforcement layer 21 and the coating layer 22 may be made of polymeric materials or other suitable materials. In some embodiments, the mesh reinforcement layer 21 and the coating layer 22 are both composed of one or more of polylactic acid, polycaprolactone, and polycarbonate to reduce the risk of blood backflow and thus reduce the probability of thrombosis.

[0067] To improve the mechanical strength of the coating layer 22 and control its absorption time, a highly crystalline mesh reinforcement layer 21 can be embedded within the coating layer 22. For example, the mesh reinforcement layer 21 can be placed on one or both sides of the coating layer 22. The material of the mesh reinforcement layer 21 includes one of polylactic acid, polycaprolactone, or polycarbonate. Furthermore, an anti-intimal hyperplasia drug can be added to the surface of the coating layer 22 in some way to further reduce the risk of vascular stenosis. The anti-intimal hyperplasia drug can be added through one or more methods such as physical spraying or chemical impregnation. The connection between the embedded branch 20 and the main stent 10 can be sutured and fixed using polymer sutures.

[0068] For example, please refer to Figure 13 and Figure 14 In the embedded branch 20, the coating layer 22 and the mesh reinforcement layer 21 can be made of the same biodegradable material, such as polylactic acid. The embedded branch 20 can be formed by electrospinning. The embedded branch 20 can include a four-layer structure, namely a coating layer 22a, a first intermediate layer 23, a second intermediate layer 24, and a coating layer 22b. The coating layers 22a and 22b can be electrospinned using the same process parameters, such as: voltage 26kV-30kV, distance between the spinneret 2001 and the rotating receiving shaft 2002 10cm-12cm, extrusion speed 8μL / min-10μL / min, lateral horizontal movement speed of the spinneret 2001 5mm / s-20mm / s, and rotation speed of the electrospun fiber collecting rotating receiving shaft 2002 500r / min-600r / min, to form a film structure. The first intermediate layer 23 undergoes electrospinning, but the horizontal movement speed of the spinneret 2001 is 5-7 times that of the coating layers 22a and 22b (because the horizontal movement is faster, only a mesh structure can be formed). The density of the first intermediate layer 23 can be adjusted by the first direction movement speed; other parameters can be referenced from the coating layers 22a and 22b. The second intermediate layer 24 undergoes electrospinning, but the spinneret does not move in the first direction; it only moves in the second direction at a speed 5-7 times that of the coating layers 22a and 22b. The density of the structure can be adjusted by the longitudinal horizontal movement speed; other parameters can be referenced from the coating layers 22a and 22b. Figure 14 In this embodiment, 2003 represents a polylactic acid solution, and 2004 represents a polylactic acid solution filament. Exemplarily, one of the first intermediate layer 23 and the second intermediate layer 24 corresponds to the first direction reinforcing filament 211, and the other corresponds to the second direction reinforcing filament 212. In this embodiment, the coating layer 22 comprises two layers, namely coating layer 22a and coating layer 22b. In other embodiments, the number of coating layers 22 may be one, three, or other layers.

[0069] For example, such as Figure 15 In the embedded branch 20, the coating layer 22 and the mesh reinforcement layer 21 can be made of different biodegradable materials, such as polycarbonate for one of the coating layer 22 and the mesh reinforcement layer 21 and polylactic acid for the other. The embedded branch 20 can be divided into two-layer structures, and the forming method can include the dip-pull method, as follows: the tooling 3001 containing the mesh reinforcement layer 21 is immersed in the coating liquid 3002 at an angle of 90°-75°, and the immersion time is maintained for a certain period of 10-30 seconds to allow the coating liquid to fully wet the mesh reinforcement layer 21. Then, the tooling 3001 containing the mesh reinforcement layer 21 is pulled out of the coating liquid 3002 at a speed of 2-10 mm / s. Finally, the solvent is evaporated by heating or other means to complete the preparation of the coating layer 22. For example, the mesh reinforcement layer 21 is a mesh polycarbonate filament, and the coating liquid 3002 is a polylactic acid solution; or, the mesh reinforcement layer 21 is a mesh polylactic acid filament, and the coating liquid 3002 is a polycarbonate solution.

[0070] Please see Figure 16 This invention also provides an iliac vein stent system, including an iliac vein stent 100 and a delivery device 200. The iliac vein stent 100 includes any of the iliac vein stents described above. The delivery device 200 is used to deliver the iliac vein stent 100 to implant it into the iliac vein within a living organism, thereby supporting the iliac vein in the compression segment and alleviating the risk of local luminal stenosis of the iliac vein in the compression segment.

[0071] Please see Figure 16 and Figure 17In some embodiments, the delivery device 200 includes a handle 203, a sheath 202, an inner sheath core 201, and an outer sheath core 204. The proximal end of the sheath 202 is connected to the handle 203. The inner sheath core 201 is slidably inserted into the sheath 202, and its proximal end is connected to the handle 203. The outer sheath core 204 is sleeved over the inner sheath core 201 and is located within the sheath 202. Its proximal end is fixedly connected to the handle 203. An iliac vein stent 100 is sleeved on the inner sheath core 201 and is located within the sheath 202. An expansion device 300 is provided in the embedded branch 20, which can expand the embedded branch 20 from a folded and molded state to a natural state. Understandably, in practical applications, the main support 10 and the embedded branch 20 are connected to form an assembly that can be retracted into the sheath 202. The operator can first implant the assembly into the iliac vein at a predetermined location within the body using the delivery device 200, and then remove the assembly from the sheath 202. After the assembly exits the sheath 202, the embedded branch 20 can be expanded from its folded and shaped state to its natural state using the expansion device 300, ensuring that the second branch 30 can be embedded within the embedded branch 20 and connected to the main stent 10. Once the embedded branch 20 is expanded to its natural state, the second branch 30 can be implanted into the body using the delivery device 200, allowing it to embed within the embedded branch 20. This enables the iliac vein stent 100 to support the blood vessel, mitigating the risk of localized vascular stenosis.

[0072] Understandably, the dilator 300 can be pre-placed within the delivery device 200. For example, the dilator 300 may be pre-placed within the delivery device 200 before the iliac vein stent system leaves the factory. Alternatively, the dilator 300 may be pre-placed within the delivery device 200 after the iliac vein stent system leaves the factory and before the iliac vein stent 100 is implanted.

[0073] Exemplarily, the expansion device 300 includes an elastic expansion device 300. For example, the expansion device 300 includes an elastic membrane, thus simplifying the structure of the expansion device 300. Understandably, the elastic membrane includes a cavity (not shown) into which a fluid such as gas or liquid can be injected to allow the expansion device 300 to expand, thereby causing the embedded branch 20 to expand from a folded, shaped state to a natural state.

[0074] Please see Figures 17 to 19In some embodiments, the iliac vein stent system further includes a connecting tube 400. A through-channel 2041 is provided on the wall of the outer sheath core 204, extending axially from the proximal end to the distal end face of the outer sheath core 204. The distal end of the connecting tube 400 passes through the through-channel 2041 and communicates with the dilator 300, while the proximal end of the connecting tube 400 extends from the through-channel 2041 and communicates with the outside of the handle 203. Gas or liquid can be supplied to the dilator 300 through the connecting tube 400, causing the dilator 300 to expand the embedded branch 20 from a folded, shaped state to a natural state. The through-channel 2041 can be used to receive the dilator 300. After the embedded branch 20 expands to its natural state and the dilator 300 returns to its original shape, the dilator 300 can be retracted into the through-channel 2041, facilitating the withdrawal of the dilator 300 along with the delivery device 200. When the dilator 300 is retracted into the through-channel 2041... Figure 19 As shown. Please refer to [the original text]. Figure 18 For example, the outer sheath core 204 is provided with a sheath core channel 2042 for the inner sheath core 201 to pass through.

[0075] It should be noted that the through-channel 2041 extends axially from the proximal end of the outer sheath core 204 to the distal end face of the outer sheath core 204. "Proximal end" or "proximal side" of the outer sheath core 204 is merely a directional description, referring to this side of the proximal end, but not a specific location. The through-channel 2041 may extend to the proximal end face of the outer sheath core 204, or it may not extend to the proximal end face of the outer sheath core 204 but instead penetrate the outer wall of the outer sheath core 204 radially beforehand. The proximal end face of the outer sheath core 204 refers to the end face of the proximal end of the outer sheath core 204. The distal end face of the outer sheath core 204 refers to the end face of the distal end of the outer sheath core 204. The same applies to the proximal end or proximal side of other components.

[0076] Please see Figure 16 , Figure 20 In some embodiments, a pipe connector 500 is movably connected to the handle 203, and the proximal end of the connecting pipe 400 is fixedly connected to and communicates with the pipe connector 500. When it is necessary to input gas or liquid into the expansion device 300, or when it is necessary to extract gas or liquid from the expansion device 300, the pipe connector 500 can be connected to the handle 203; when it is not necessary to input gas or liquid into the expansion device 300, or when it is not necessary to extract gas or liquid from the expansion device 300, the pipe connector 500 can be detached from the handle 203. Because the proximal end of the connecting pipe 400 is fixedly connected to and communicates with the pipe connector 500, gas or liquid can enter the connecting pipe 400 through the pipe connector 500 and then reach the expansion device 300; gas or liquid in the expansion device 300 can also enter the pipe connector 500 through the connecting pipe 400 and be discharged.

[0077] Before the iliac vein stent 100 is inserted into the sheath 202, the dilator 300 and the connecting tube 400 can reach the distal end of the delivery device 200 through the through-channel 2041 from the proximal end of the delivery device 200 and extend from the sheath 202. The dilator 300 is then pre-placed in the embedded branch 20. The assembly formed by connecting the main stent 10 and the embedded branch 20 is then compressed and inserted into the sheath 202. Because the dilator 300 is connected to the connecting tube 400, and the connecting tube 400 has a certain axial support strength, the presence of the dilator 300 not only dilates the embedded branch 20 but also improves the support performance of the embedded branch 20 side of the entire iliac vein stent 100, providing a certain axial restraint effect on the iliac vein stent 100 and reducing the risk of shortening of the iliac vein stent 100.

[0078] After the assembly formed by connecting the main support 10 and the embedded branch 20 by pulling handle 203 is released, and before the second branch 30 is inserted, saline solution can be injected into the dilator 300 through the connector 500 using a syringe. The dilator 300 expands until it opens the folded and shaped embedded branch 20. After the internal channel 25 of the embedded branch 20 (see Figure 4(A)) is expanded, a channel is established for the implantation of the second branch 30. After the channel is established, the saline solution is withdrawn with a syringe, and the dilator 300 returns to its original state. One end of the connecting tube 400 is connected to the dilator 300, and the other end of the connecting tube 400 is connected to the connector 500. Saline solution can enter the connecting tube 400 through the connector 500, thereby entering the dilator 300. Please refer to... Figure 16 As shown, pipe fitting 500 is threadedly connected to handle 203. See also... Figure 20 As shown, after the expansion device 300 returns to its original position, rotating the pipe joint 500 separates it from the handle 203. Then, pulling the pipe joint 500 moves the connecting pipe 400 and the expansion device 300 towards the proximal end, pulling the expansion device 300 into the through channel 2041. Finally, the expansion device 300 can be withdrawn from the birth object along with the conveyor 200.

[0079] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific method step, feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific method steps, features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An iliac vein stent, characterized in that, include: The main support includes a main body and a first branch connected to the distal end of the main body; An embedded branch is provided inside the main body after being folded and shaped, and part of the outer wall of the embedded branch is fixedly connected to the inner wall of the main body support; compared with the natural state, the minimum distance between the embedded branch and the center of the main body is increased in the folded and shaped state. The second branch can be embedded in the embedded branch and connected to the main support; In its natural state, the cross-section of the embedded branch is annular; in its folded and shaped state, at least a portion of the inner walls of the embedded branch are brought close to each other, resulting in a non-annular cross-sectional shape for the embedded branch.

2. The iliac vein stent according to claim 1, characterized in that, In the folded and shaped state, the embedded branches bend and fold to form an arc shape.

3. The iliac vein stent according to claim 2, characterized in that, In the folded and shaped state, the two free ends of the bow-shaped embedded branch are further bent toward each other to form a C-shape.

4. The iliac vein stent according to claim 1, characterized in that, The embedded branch includes a mesh reinforcement layer and a coating layer, wherein the mesh reinforcement layer is disposed on the coating layer.

5. The iliac vein stent according to claim 4, characterized in that, The mesh reinforcement layer includes a plurality of first-direction reinforcing filaments and a plurality of second-direction reinforcing filaments, which overlap to form the mesh reinforcement layer, and the coating layer covers one or both sides of the mesh reinforcement layer.

6. The iliac vein stent according to claim 4, characterized in that, The mesh reinforcement layer and the coating layer are composed of one or more of polylactic acid, polycaprolactone, and polycarbonate.

7. An iliac vein stent system, comprising the iliac vein stent and delivery device as described in any one of claims 1-6, characterized in that, The conveyor includes: handle; A sheath, the proximal end of which is connected to the handle; The inner sheath core is slidably inserted into the sheath tube and the proximal side of the inner sheath core is connected to the handle; An outer sheath core is fitted over the inner sheath core and located within the sheath tube; the proximal end of the outer sheath core is fixedly connected to the handle. The iliac vein stent is fitted onto the inner sheath core and located inside the sheath tube. An expansion device is provided in the embedded branch, which can expand the embedded branch from a folded and shaped state to a natural state.

8. The iliac vein stent system according to claim 7, characterized in that, It also includes a connecting tube, and the outer sheath core has a through channel on its tube wall. The through channel extends axially from the proximal end of the outer sheath core to the distal end face of the outer sheath core. The distal end of the connecting tube passes through the through channel and communicates with the expansion device. The proximal end of the connecting tube extends out of the through channel and communicates with the outside of the handle.

9. The iliac vein stent system according to claim 8, characterized in that, A pipe connector is movably connected to the handle, and the proximal end of the connecting pipe is fixedly connected to and communicates with the pipe connector.

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