Radiotherapy stent and retrieval system

Abstract

The present application relates to a kind of radiotherapy stents and recovery system.Radiotherapy stent recovery system includes: radiotherapy stent, including stent main body, at least the end of the proximal end of the stent main body extends along axis in natural state, recovery system includes recovery device, recovery device includes first sheath tube, first sheath core and second sheath core, proximal end connector is fixedly connected with first sheath core, distal end connector is fixedly connected with second sheath core;First state, proximal end connector can be pulled by first sheath core and be moved away relative to distal end, to reduce the outer diameter of stent main body;Second state, first sheath tube and the stent main body of reduced outer diameter can be relatively close to make radiotherapy stent enter first sheath tube.When radiotherapy stent is recovered to first sheath tube, radiotherapy stent is not prone to scratch tissue pipeline wall, and the wall of tissue pipeline is not prone to cause damage.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, and in particular to radiotherapy stents and retrieval systems. Background Technology

[0002] In recent years, the incidence of cancer has shown a significant upward trend. Currently, approximately 70% of cancer patients require radiotherapy during treatment, and about 40% of these patients can be cured through radiotherapy. This has made radiotherapy increasingly prominent in cancer treatment. Currently, there is a relatively precise radiotherapy method that can minimize damage to healthy tissues. This method involves placing radioactive material within a radiotherapy stent and delivering the stent to the lesion site within the patient's body, thus targeting the diseased tissue for specific treatment. After treatment, the radiotherapy stent is retrieved and removed from the body. However, in related technologies, if the radiotherapy stent has good anchoring, it is not easy to remove after implantation. During removal, it is easy to scrape the tissue wall, causing damage. Conversely, if the anchoring is poor, it is prone to detachment from the implantation site. Summary of the Invention

[0003] Based on this, the present invention proposes a radiotherapy stent and a recycling system, which increases the recyclability of the radiotherapy stent while ensuring the implantation strength of the stent.

[0004] This invention proposes a radiotherapy stent, comprising:

[0005] A radiotherapy stent includes a stent body comprising a connected drug-loaded segment and a support segment, the stent body also including a stress-free natural state and a stress-compressed state, the drug-loaded segment including a lumen for containing radioactive material, and at least the proximal end of the stent body extending along an axis in the natural state.

[0006] In one embodiment, the support section includes a helical structure, and the drug-loaded section is connected to the support section and located on the axis of the stent body or on one side of the axis of the stent body.

[0007] In one embodiment, the stent body includes a plurality of drug-loaded segments and a plurality of support segments, with at least one drug-loaded segment located between two adjacent support segments.

[0008] In one embodiment, each of the drug-loaded segments has a support segment at both its distal and proximal ends.

[0009] In one embodiment, the support section includes a helical section and a transition section, the transition section extending axially and connecting two adjacent helical sections.

[0010] In one embodiment, two adjacent transition segments are distributed circumferentially and are parallel to each other.

[0011] In one embodiment, the transition section includes an anchoring reinforcement structure.

[0012] The aforementioned radiotherapy stent, because at least the proximal end of the stent body extends along the axis in its natural state, can be directly aligned with the sheath during retrieval, thereby greatly enhancing the ease of retrieval of the radiotherapy stent.

[0013] The present invention also proposes a recycling system, comprising:

[0014] A radiotherapy stent, used for placement within tissue channels, comprises a stent body, a proximal connector, and a distal connector. The stent body includes a helical curved tube and includes a natural, unstressed state and a compressed state. The curved tube includes a lumen for containing radioactive material. A retrieval device includes a first sheath, a first sheath core, and a second sheath core. The proximal connector is detachably connected to the first sheath core, and the distal connector is detachably connected to the second sheath core. In a first state, the proximal connector can be pulled away from the distal end by the first sheath core to reduce the outer diameter of the stent body. In a second state, the first sheath and the stent body with reduced outer diameter can be brought closer together so that the radiotherapy stent enters the first sheath.

[0015] In one embodiment, in the first state, the position of the distal connector remains unchanged; or, in the first state, the distal connector pulled by the second sheath core moves in the opposite direction to the proximal connector pulled by the first sheath core.

[0016] In one embodiment, in the first state, the proximal end moves away from the distal end until the support body is in a straight tube shape.

[0017] The aforementioned recovery system includes a stent body comprising a helical curved tube. The stent body exists in both a relaxed, unloaded state and a compressed, loaded state. The curved tube includes a lumen for containing radioactive material. A proximal connector is attached to the proximal end of the stent body, and a distal connector is attached to the distal end. The proximal connector is fixedly connected to a first sheath core, and the distal connector is fixedly connected to a second sheath core. During recovery, in the first state, the proximal connector is pulled away from the distal end by the first sheath core, thereby reducing the outer diameter of the helical stent body. This reduces the resistance between the stent body and the wall of the tissue conduit, potentially even causing separation. In the second state, the first sheath tube moves relative to the stent body with its reduced outer diameter, allowing the stent body to enter the first sheath tube for recovery. In the second state, due to the reduction in the outer diameter of the stent body, the supporting force between the stent body and the wall of the human tissue channel becomes smaller, or even separates from the wall of the human tissue channel. Therefore, during the relative movement of the stent body and the first sheath, the scraping of the stent body against the human tissue channel is reduced or even eliminated, making it less likely to cause damage to the wall of the human tissue channel. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a radiotherapy stent placed inside a human tissue conduit (straight tube) according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of a radiotherapy stent placed inside a human tissue conduit (bend) according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of a radiotherapy stent being retrieved at a certain moment in a related technology.

[0021] Figure 4 for Figure 3 A schematic diagram of another moment in the embodiment when the radiotherapy stent is retrieved;

[0022] Figure 5 This is a schematic diagram of a certain moment in the radiotherapy stent retrieval process according to an embodiment of the present invention;

[0023] Figure 6 for Figure 5 Schematic diagram of another moment in the radiotherapy stent retrieval process in the embodiment;

[0024] Figure 7 This is a schematic diagram of a certain moment in the radiotherapy stent retrieval process according to an embodiment of the present invention;

[0025] Figure 8 for Figure 7 Schematic diagram of another moment in the radiotherapy stent retrieval process in the embodiment;

[0026] Figure 9This is a schematic diagram of a certain moment in the radiotherapy stent retrieval process according to an embodiment of the present invention;

[0027] Figure 10 for Figure 9 Schematic diagram of another moment in the radiotherapy stent retrieval process in the embodiment;

[0028] Figure 11 This is a schematic diagram of a certain moment in the radiotherapy stent retrieval process according to an embodiment of the present invention;

[0029] Figure 12 for Figure 11 Schematic diagram of another moment in the radiotherapy stent retrieval process in the embodiment;

[0030] Figure 13 This is a schematic diagram of a radiotherapy stent placed inside a human tissue conduit (straight tube) in one embodiment of the present invention;

[0031] Figure 14 This is a schematic diagram of a radiotherapy stent placed inside a human tissue conduit (straight tube) in another embodiment of the present invention;

[0032] Figure 15 This is a schematic diagram of a radiotherapy stent placed inside a human tissue conduit (straight tube) in another embodiment of the present invention;

[0033] Figure 16 This is a schematic diagram of a radiotherapy stent placed inside a human tissue conduit (straight tube) in another embodiment of the present invention.

[0034] Figure label:

[0035] Organize pipeline 100;

[0036] Radiotherapy stent 200, stent body 210, drug-loaded section 2101, support section 2102, spiral section 2103, transition section 2104, wave section 2105, proximal connector 220, distal connector 230;

[0037] First sheath core 310, first inner sheath core 311, first outer sheath core 312, first sheath tube 320, first fixing member 330;

[0038] Second sheath core 410, second sheath tube 420;

[0039] Positioning component 500, first through hole 510, second through hole 520;

[0040] Card slot 610, insertion slot 611, limiting slot 612, card block 620, card claw 621, limiting block 622, first magnetic component 630, second magnetic component 640, inlet 641, guide component 650;

[0041] Hook 710, cable 720, connecting rod 730, capture head 740. Detailed Implementation

[0042] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0043] 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," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0044] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0047] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0048] 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 perpendicular to the "axial direction." Based on this principle, the "axial direction" and "radial direction" of any component of a medical device are defined. In the accompanying drawings of this application, the "proximal end" is the right end as shown in the viewpoint, and the "distal end" is the left end as shown in the viewpoint.

[0049] See Figures 1 to 2 An embodiment of the present invention provides a radiotherapy stent 200, comprising a stent body 210. The stent body 210 abuts against the inner wall of a tissue channel 100 at the implantation site. The radiotherapy stent 200 is stably anchored to the lesion site by the frictional force between the stent body 210 and the channel 100. The tissue channel 100 is the channel where the tumor or lesion is located, or the channel closest to the tumor. The radiotherapy stent 200 carries radioactive material and can perform radiotherapy on the lesion site. After treatment, the radiotherapy stent 200 is retrieved to a sheath using a retrieval device, and the sheath is removed from the body. See also... Figures 3 to 4In related technologies, when retrieving the radiotherapy stent 200 from the tissue channel 100, the first sheath 320 is typically inserted into the tissue channel 100 to the proximal end of the radiotherapy stent 200. Then, the first sheath core 310 is inserted into the first sheath 320, passing through the first sheath 320 and connecting to the proximal end of the radiotherapy stent 200. Subsequently, pulling the first sheath core 310 causes the radiotherapy stent 200 to move from distal to proximal within the tissue channel 100. The radiotherapy stent 200 gradually deforms and enters the first sheath 320, abutting against the inner wall of the first sheath 320, thus being stably retrieved within the first sheath 320. Once the radiotherapy stent 200 is fully retracted into the first sheath 320, the first sheath 320 is then removed from the body. However, in this recycling method, that is, during the process of pulling the radiotherapy stent 200 into the first sheath tube 320 by the first sheath core 310, the first sheath core 310 is always pressed against the inner wall of the tissue channel 100, which will cause scraping to the inner wall of the tissue channel 100 and easily cause damage to the inner wall of the tissue channel 100.

[0050] See Figure 5 , Figure 7 , Figure 9 and Figure 11 In this application, the radiotherapy stent retrieval system includes a radiotherapy stent 200 and a retrieval device. The radiotherapy stent 200 is used to place within a tissue conduit 100 and includes a stent body 210, a proximal connector 220, and a distal connector 230. The stent body 210 includes a helically wound curved tube. The stent body 210 is elastic to withstand the wall of the tissue conduit 100, and the lumen of the curved tube is used to contain radioactive material. The proximal end of the stent body 210 is connected to the proximal connector 220, and the distal end of the stent body 210 is connected to the distal connector 230. The retrieval device includes a first sheath 320, a first sheath core 310, and a second sheath core 410. The proximal connector 220 is detachably connected to the first sheath core 310, and the distal connector 230 is detachably connected to the second sheath core 410. When the radiotherapy stent 200 is retrieved, there are two states: a first state and a second state. In the first state, the proximal connector 220 and the distal connector 230 are connected to the first sheath core 310 and the second sheath core 410, respectively. In this state, the proximal connector 220 can be pulled away from the distal end by the first sheath core 310, reducing the outer diameter of the stent body 210 and causing it to move radially away from the tissue channel 100. In the second state, the first sheath tube 320 and the stent body 210 with its reduced outer diameter can approach each other, allowing the radiotherapy stent 200 to enter the first sheath tube 320.

[0051] Specifically, in the first state, when the proximal connector 220 is pulled away from the distal end by the first sheath core 310, the proximal and distal ends of the stent body 210 move away from each other, causing the stent body 210 to be stretched and elastically deformed. The outer diameter of the spiral stent body 210 decreases, and the stent body 210 moves radially away from the tissue channel 100. In the second state, if the outer diameter of the stent body 210 is still larger than the inner diameter of the first sheath tube 320 after the reduction, the stent body 210 will further elastically deform under the limitation of the diameter of the first sheath tube 320 during the relative movement between the first sheath tube 320 and the stent body 210, thereby entering the first sheath tube 320. After entering the first sheath tube 320, the stent body 210 will elastically abut against the inner wall of the first sheath tube 320. If the outer diameter of the stent body 210 is reduced to be smaller than the inner diameter of the first sheath 320, then during the relative movement of the first sheath 320 and the stent body 210, the stent body 210 can directly enter the first sheath 320 without contacting the inner wall of the first sheath 320. In the second state, after most of the stent body 210 has entered the first sheath 320, the fixing relationship between the distal connector 230 and the second sheath core 410 is released, and the first sheath 320 and the stent body 210 continue to move closer to each other, so that the radiotherapy stent 200 is completely retracted into the first sheath 320. In the second state, when the first sheath 320 and the stent body 210 move relative to each other, the position of the first sheath 320 may remain unchanged, and the first sheath core 310 and the second sheath core 410 may move synchronously toward the first sheath 320, thereby causing the stent body 210 to move toward the first sheath 320. Alternatively, the positions of the first sheath core 310 and the second sheath core 410 may remain unchanged, that is, the position of the stent body 210 may remain unchanged, and the first sheath 320 may move toward the stent body 210. Alternatively, the first sheath 320 and the support body 210 can move closer together simultaneously.

[0052] In this embodiment, in the first state, the stent body 210 is stretched and elastically deformed, and the outer diameter of the spiral stent body 210 decreases. Therefore, the resistance between the stent body 210 and the inner wall of the tissue channel 100 decreases, or even the stent body 210 does not contact the inner wall of the tissue channel 100 at all. Based on this, in the second state, when the outer diameter of the stent body 210 decreases, during the relative movement of the first sheath 320 and the stent body 210, if the stent body 210 moves, the scraping force of the stent body 210 on the inner wall of the tissue channel 100 is weakened, or even non-existent, thus making it less likely to cause damage to the tissue channel 100.

[0053] In some embodiments, in the first state, the position of the distal connector 230 remains unchanged. Specifically, in the first state, the position of the second sheath core 410 within the tissue channel 100 remains unchanged, thereby keeping the position of the distal connector 230 connected to the second sheath core 410 within the tissue channel 100 unchanged. When the proximal connector 220 is pulled by the first sheath core 310, the distal position of the radiotherapy stent 200 is restricted by the second sheath core 410 and does not move with the proximal end. The proximal end then gradually moves away from the distal end, stretching and deforming the stent body 210, thus reducing the outer diameter of the stent body 210. Alternatively, in other embodiments, in the first state, the distal connector 230 pulled by the second sheath core 410 moves in the opposite direction to the proximal connector 220 pulled by the first sheath core 310. Specifically, in the first state, the second sheath core 410 moves away from the distal end within the tissue channel 100, and the first sheath core 310 moves away from the proximal end within the tissue channel 100. Therefore, the proximal connector 220 will be pulled away from the distal end by the first sheath core 310, while the distal connector 230 will be pulled away from the proximal end by the second sheath core 410. That is, the proximal and distal ends of the radiotherapy stent 200 move in opposite directions at the same time to increase the distance between the proximal and distal ends, so as to stretch the stent body 210 to deform and reduce the outer diameter of the stent body 210.

[0054] In some embodiments, in the first state, the proximal end moves away from the distal end until the stent body 210 becomes a straight tube. As mentioned earlier, in the first state, the proximal and distal ends of the stent body 210 move away from each other, thereby stretching and elastically deforming the stent body 210. The outer diameter of the spiral stent body 210 decreases, and the resistance between the stent body 210 and the inner wall of the tissue channel 100 decreases, or even completely avoids contact with the inner wall of the tissue channel 100. Preferably, the degree of stretching deformation is relatively large, pulling the stent body 210 from a spiral shape to a straight tube shape, so that it completely avoids contact with the inner wall of the tissue channel 100. With this configuration, in the second state, during the relative movement of the first sheath 320 and the stent body 210, if the stent body 210 moves, the stent body 210 will not contact the inner wall of the tissue channel 100, thus preventing scratching and damage to the inner wall of the tissue channel 100.

[0055] See Figures 5 to 6In some embodiments, the first sheath core 310 is located on the proximal side of the radiotherapy stent 200, and the second sheath core 410 is located on the distal side of the radiotherapy stent 200. Specifically, the first sheath core 310 and the second sheath core 410 enter the body from different locations, for example, one enters from the leg and the other from the neck. Specifically, in some embodiments, the retrieval device further includes a second sheath tube 420. The first sheath tube 320, the radiotherapy stent 200, and the second sheath tube 420 are arranged in a direction from proximal to distal. The first sheath core 310 passing through the first sheath tube 320 is connected to the proximal connector 220, and the second sheath core 410 passing through the second sheath tube 420 is connected to the distal connector 230. Specifically, the first sheath tube 320 and the second sheath tube 420 enter the body from different locations. After passing through the first sheath tube 320, the first sheath core 310 is fixedly connected to the proximal connector 220, and after passing through the second sheath tube 420, the second sheath core 410 is fixedly connected to the distal connector 230. In the first state, if the proximal and distal ends of the radiotherapy stent 200 need to move in opposite directions simultaneously to stretch the stent body 210, then the first sheath core 310 and the second sheath core 410 can move in opposite directions synchronously, that is, the first sheath core 310 and the second sheath core 410 can move in opposite directions along their respective directions of insertion into the human body.

[0056] See Figure 7 , Figure 9 and Figure 11 In other embodiments, both the first sheath core 310 and the second sheath core 410 are located on the proximal side of the radiotherapy stent 200. Specifically, the first sheath core 310 and the second sheath core 410 can be inserted into the body from the same location, for example, both from the leg or both from the neck. Inserting from the same location makes the operation more convenient and requires fewer incisions in the body.

[0057] See Figures 7 to 8Specifically, in some embodiments, the recovery device further includes a second sheath 420, with the distal connector 230 facing proximally. The first sheath 320 and the second sheath 420 are located on the proximal side of the radiotherapy stent 200 and are arranged radially along the radiotherapy stent 200. A first sheath core 310 passing through the first sheath 320 is connected to the proximal connector 220, and a second sheath core 410 passing through the second sheath 420 is connected to the distal connector 230. Specifically, the first sheath 320 and the second sheath 420 extend into the tissue channel 100 from the same position. The first sheath core 310 is detachably connected to the proximal connector 220 after passing through the first sheath 320, and the second sheath core 410 is detachably connected to the distal connector 230 after passing through the second sheath 420. The distal connector 230 has a position for connecting to the second sheath core 410 facing proximally, allowing the second sheath core 410, which extends from the proximal side, to be detachably connected to the distal connector 230. In the first state, if the proximal and distal ends of the radiotherapy stent 200 need to move in opposite directions simultaneously to stretch the stent body 210, then the first sheath core 310 and the second sheath core 410 can move in opposite directions synchronously, that is, the first sheath core 310 moves in the opposite direction of the direction it extends into the human body, and the second sheath core 410 moves in the direction it extends into the human body.

[0058] In some embodiments, the first sheath 320 and the second sheath 420 are integrally connected to form a sheath assembly. Specifically, the first sheath 320 and the second sheath 420 are fixedly connected as one unit, or they are directly integrally formed into a single component. After being integrally connected, their internal cavities can remain separate, or their internal cavities can be interconnected. This arrangement can further simplify the structure of the recovery device and simplify the operation steps, eliminating the need to insert two separate sheaths into the body.

[0059] See Figures 9 to 10In some embodiments, the first sheath 320 and the second sheath 420 are integrally connected to form a sheath assembly, and the inner lumen of the first sheath 320 communicates with the inner lumen of the second sheath 420. The sheath assembly also includes a positioning member 500, which is installed inside the sheath assembly. The positioning member 500 has a first through hole 510 and a second through hole 520. The first sheath core 310 passes through the first sheath 320 and the first through hole 510, and the first sheath core 310 can rotate within the first through hole 510. The second sheath core 410 passes through the second sheath 420 and the second through hole 520, and the second sheath core 410 can rotate within the second through hole 520. Specifically, the positioning member 500 is installed in the inner lumen of the sheath assembly and is located at one end near the radiotherapy stent 200. Specifically, the positioning element 500 is partially located within the inner cavity of the first sheath 320 and partially within the inner cavity of the second sheath 420. The positioning element 500 can be installed through various methods such as bonding, snap-fitting, or integral molding. If both the first sheath 320 and the second sheath 420 are cylindrical and connected through their respective sidewalls, the resulting sheath assembly is approximately a hollow gourd or figure-eight shape, and the positioning element 500 is also set to the corresponding shape. Alternatively, the first sheath 320 and the second sheath 420 can together form a cylindrical sheath assembly, with each occupying half of the cylindrical tube. In this embodiment, by connecting the first sheath 320 and the second sheath 420 into one unit, the structure of the recovery device can be further simplified, and the operation steps can be simplified, eliminating the need to insert two separate sheaths into the body; at the same time, by setting the positioning member 500, the first sheath core 310 and the second sheath core 410 can be limited, so that the two can move independently after extending out of the sheath assembly, and are less likely to collide and entangle with each other, causing interference.

[0060] See Figures 11 to 12 In some embodiments, the distal connector 230 faces the proximal end, and the first sheath 320 is located on the proximal side of the particle support 200. A first sheath core 310 passing through the first sheath 320 is connected to the proximal connector 220. The first sheath core 310 has a first channel arranged axially, and a second sheath core 410 passing through the first channel is connected to the distal connector 230. Specifically, the first sheath core 310 is also used as the second sheath 420, that is, the first sheath core 310 is provided with a first channel extending axially for the second sheath core 410 to pass through. This arrangement eliminates the need for a separate second sheath 420, simplifying the structure of the recovery device and the operation steps, as it eliminates the need to insert two separate sheaths into the body.

[0061] Alternatively, in some embodiments, the distal connector 230 faces the proximal end, and the first sheath 320 is located on the proximal side of the particle support 200; a second sheath core 410 passing through the first sheath 320 is connected to the distal connector 230, and the second sheath core 410 has a second channel arranged axially, through which the first sheath core 310 is connected to the proximal connector 220. Specifically, the second sheath core 410 is provided with a second channel extending axially for the first sheath core 310 to pass through. This arrangement allows for the use of only one sheath, simplifying the structure of the recovery device and the operation steps, eliminating the need to insert two separate components into the body.

[0062] In some embodiments, the particle scaffold 200 is placed within a tissue conduit 100. The particle scaffold 200 includes a scaffold body 210 and a connecting assembly. The scaffold body 210 is formed by a hollow tube spirally wound around itself. The scaffold body 210 is elastic to withstand the wall of the tissue conduit 100, and the lumen of the hollow tube is used to contain radioactive material. The connecting assembly includes a proximal connector 220 connected to the proximal end of the scaffold body 210 and a distal connector 230 connected to the distal end of the scaffold body 210. The proximal connector 220 is used to connect to a first sheath core 310 of a recovery device, and the distal connector 230 is used to connect to a second sheath core 410 of a recovery device. In a first state, the proximal connector 220 can be pulled away from the distal end by the first sheath core 310 to reduce the outer diameter of the scaffold body 210. In a second state, the scaffold body 210 with its reduced outer diameter can move relative to the first sheath core 320 to allow the particle scaffold 200 to enter the first sheath core 320. The particle scaffold 200 in this embodiment is the same as the particle scaffold 200 in the aforementioned embodiments of the particle scaffold recycling system.

[0063] In some embodiments, the method for retrieving the radiotherapy stent 200 includes the following steps:

[0064] S110 connects the first sheath core 310 to the proximal end of the radiotherapy stent 200 and the second sheath core 410 to the distal end of the radiotherapy stent 200;

[0065] S120 at least pulls the proximal end away from the distal end through the first sheath core 310 to reduce the outer diameter of the spiral radiotherapy stent 200;

[0066] S130 brings the radiotherapy stent 200 closer to the first sheath 320 until the radiotherapy stent 200 enters the first sheath 320.

[0067] In other embodiments, the method for retrieving the radiotherapy stent 200 includes the following steps:

[0068] S210 connects the first sheath core 310 to the proximal end of the radiotherapy stent 200 and the second sheath core 410 to the distal end of the radiotherapy stent 200;

[0069] S220 at least pulls the distal end of the radiotherapy stent 200 away from the proximal end of the radiotherapy stent 200 through the first sheath core 310, so as to reduce the outer diameter of the spiral-shaped radiotherapy stent 200.

[0070] S230 brings the radiotherapy stent 200 closer to the first sheath 320 until the radiotherapy stent 200 enters the first sheath 320.

[0071] The specific operating steps can be referred to in the foregoing embodiments.

[0072] It should be noted that when the first sheath core 310 and the second sheath core 410 mentioned in the foregoing embodiments pass through their respective sheath tubes, the radial dimension of the sheath core is smaller than the radial dimension of the sheath tube through which it passes, so as to ensure that the sheath core can be inserted as freely as possible inside the sheath tube and is not easily hindered by friction from the inner wall of the sheath tube.

[0073] As previously described, when the radiotherapy stent 200 is implanted into the human body, the stent body 210 includes a receiving cavity for receiving radioactive materials. Generally, the receiving cavity extends along the threaded structure of the stent body 210, that is, it is located inside the threaded structure. In addition, in order to facilitate the retrieval of the radiotherapy stent 200, at least the proximal end of the stent body 210 of the radiotherapy stent 200 extends along the axis in its natural state.

[0074] In some embodiments, the structure of the stent body 210 of the radiotherapy stent 200 changes, referring to... Figure 13 The stent body 210 includes a drug-loaded segment 2101 and a support segment 2102. The support segment 2102 is spirally distributed and abuts against the inner wall of the tissue channel 100. The drug-loaded segment 2101 is connected to the support segment 2102 and is located on the axis of the stent body 210. Therefore, the drug-loaded segment 2101 will not come into close contact with any surface of the tissue channel 100, thus avoiding excessive radiation due to the drug-loaded segment 2101 being too close to the tissue at its contact point. Secondly, since many radioactive materials are in a liquid state when loaded into the drug-loaded segment 2101, if the drug-loaded segment 2101 is spirally abutting against the inner wall of the tissue channel 100, the radioactive material may flow to one side of the stent body 2101 depending on the implantation location or the body's posture, thereby affecting the treatment effect.

[0075] Furthermore, the drug-loaded segment 2101 is located on one side of the axis of the stent body 210. When the lesion appears on one side of the tissue channel 100, the drug-loaded segment 2101 located on one side can be closer to the lesion location relative to the axis position, thereby obtaining a better treatment effect.

[0076] In some embodiments, refer to Figure 14The stent body includes multiple drug-loaded segments 2101 and multiple support segments 2102. Preferably, at least one drug-loaded segment 2101 is located between two support segments 2102 to achieve the most stable implantation effect. As a further optimization of this embodiment, all drug-loaded segments 2101 have support segments 2102 at both their distal and proximal ends, thereby ensuring that the area loaded with radioactive material is stably maintained in the axial position, maintaining the stability of the drug-loaded segment 2101 even when the tissue channel 100 deforms or moves.

[0077] In some embodiments, refer to Figure 15 The support section 2102 of the support body 210 also includes a helical section 2103 and a transition section 2104. The transition section 2104 extends axially and connects two adjacent helical sections 2103. Preferably, the two adjacent transition sections 2104 are located at different positions in the circumferential direction (i.e., the two adjacent transition sections 2104 are parallel) to provide axial support force at multiple circumferential positions of the entire support body 210, preventing the support body 210 from shortening from multiple circumferential positions.

[0078] Furthermore, a portion of the support body 210 that comes into contact with the human body is coated with a material that increases friction (such as silicone or other polymer materials), or the portion is roughened (such as by sanding); preferably, this portion is a transition section 2104.

[0079] Furthermore, in some embodiments, reference is made to Figure 16 The transition section 2014 of the stent body 210 is also provided with a wave section 2105 extending along the axial direction. The wave section 2105 is partially embedded into the tube tissue 100, which can increase the anchoring capacity of the stent body 210. In other words, the transition section 2014 includes an anchoring reinforcement structure. At the same time, by means of the above removal method, the anchoring capacity of the stent body 210 can be increased while avoiding scratching and damage to the inner wall of the tissue tube when removing the stent.

[0080] In some embodiments, the stent body 210 includes a solid segment 211 and a drug-loaded segment 212 with an internal cavity. Multiple drug-loaded segments 212 may be provided, each including a drug placement inlet for inserting medication. After the medication is inserted, the drug placement inlet is sealed. The solid segment 211 serves to enhance the radial support capacity of the stent 210 and increase its resistance to displacement.

[0081] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A radiotherapy stent, characterized in that, The stent body includes a connected drug-loaded section and a support section, and the stent body also includes a natural, unstressed state and a compressed state under stress. The drug-loaded section includes a lumen for containing radioactive material, and at least the proximal end of the stent body extends along an axis in the natural state. The support section includes a helical section and a transition section. The transition section extends axially and connects two adjacent helical sections. The two adjacent transition sections are distributed circumferentially and are parallel to each other to provide axial support force at multiple circumferential positions of the support body and prevent the support body from shortening.

2. The radiotherapy stent according to claim 1, characterized in that, The support section includes a spiral structure, and the drug-loaded section is connected to the support section and is located on the axis of the stent body or on one side of the axis of the stent body.

3. The radiotherapy stent according to claim 1, characterized in that, The stent body includes multiple drug-loaded segments and multiple support segments, with at least one drug-loaded segment located between two adjacent support segments.

4. The radiotherapy stent according to claim 3, characterized in that, Each of the drug-loaded segments has a support segment at both its distal and proximal ends.

5. The radiotherapy stent according to claim 1, characterized in that, The surface of a portion of the support body that contacts the human body is coated with a material that increases friction, or the surface of a portion of the support body that contacts the human body is roughened.

6. The radiotherapy stent according to claim 5, characterized in that, The aforementioned region is the transition section.

7. The radiotherapy stent according to claim 1, characterized in that, The transition section includes an anchoring reinforcement structure.

8. A recycling system, characterized in that, The radiotherapy stent comprising any one of claims 1-7, the radiotherapy stent comprising a connecting assembly, the connecting assembly comprising a proximal connector connected to the proximal end of the stent body and a distal connector connected to the distal end of the stent body; the retrieval system comprising a retrieval device comprising a first sheath, a first sheath core and a second sheath core, the proximal connector being detachably connected to the first sheath core and the distal connector being detachably connected to the second sheath core; In the first state, the proximal connector can be pulled by the first sheath core to move away from the distal end, thereby reducing the outer diameter of the support body; In the second state, the first sheath and the reduced outer diameter of the stent body can be brought relatively close together so that the radiotherapy stent can enter the first sheath.

9. The recycling system according to claim 8, characterized in that, In the first state, the position of the distal connector remains unchanged; or, in the first state, the distal connector pulled by the second sheath core moves in the opposite direction to the proximal connector pulled by the first sheath core.

10. The recycling system according to claim 8, characterized in that, In the first state, the proximal end moves away from the distal end until the main body of the stent is in the shape of a straight tube.

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