Radiotherapy stent

Abstract

This invention relates to a radiotherapy stent, comprising a stent body capable of elastically abutting against the wall of a tissue channel, the stent body including an inner cavity for containing radioactive material; and a sealing plug detachably disposed at the outlet of the inner cavity to close or open the outlet. This radiotherapy stent, by incorporating the sealing plug and a covering, achieves a seal on the outlet of the inner cavity containing radioactive material, avoiding leakage problems caused by stent body damage or excessive bending.

Description

Technical Field

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

[0002] In recent years, the incidence of cancer has shown a significant upward trend. Currently, approximately 70% of cancer patients require radiotherapy, 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, particularly for esophageal and biliary tract cancers. These radiotherapy stents are typically spring-shaped, elastically supporting the walls of the body's tissues and preventing displacement after being delivered to the lesion site. During manufacturing, the stent is generally heat-shaped to achieve the desired spring-like form. However, in related technologies, the structure of some radiotherapy stents makes them difficult to heat-set during the heat-setting process. This invention mentions a method of reducing the difficulty of setting by setting grooves. However, the lumen of the radiotherapy stent carries radioactive material, which can be used to treat the lesion site with radiotherapy. After the treatment is completed, the radiotherapy stent is retrieved and removed from the body by a retrieval device. Therefore, the radiotherapy stent must ensure the airtightness of the lumen. However, if the multiple grooves on the stent body are penetrated, that is, if the stent body is damaged, or if the stent is bent excessively, the stent will lose its airtightness. Therefore, it is necessary to seal the surface of the radiotherapy stent. Summary of the Invention

[0003] Based on this, the present invention proposes a radiotherapy stent to solve the sealing problem when the stent body is damaged or the stent is excessively bent.

[0004] Radiation therapy stents, including:

[0005] The stent body is elastically supported against the wall of the tissue duct, and the stent body includes an inner cavity for accommodating radioactive materials;

[0006] A sealing plug is detachably disposed at the outlet position of the inner cavity to close or open the outlet.

[0007] In one embodiment, the radiotherapy stent further includes an inner tube covering the inner wall of the lumen, a portion of which extends out of the stent body and is flipped at an end of the stent body to form a flipped portion, the flipped portion covering at least a portion of the outer side of the stent body.

[0008] In one embodiment, the sealing plug includes a baffle facing the support body, the baffle forming an opening facing the support body to seal the inner cavity.

[0009] In one embodiment, an auxiliary baffle extends inward from the end of the baffle, and the auxiliary baffle abuts against the film, the support body, or the flipping part.

[0010] In one embodiment, the middle portion of the sealing plug protrudes towards the support body to form a protrusion, the protrusion being inserted into the interior of the inner tube, and the flipping portion being located outside the protrusion.

[0011] In one embodiment, the distance between the baffle and the support body is less than or equal to the thickness of the flipping portion.

[0012] In one embodiment, the auxiliary baffle is located between the end of the support body and the groove closest to the end.

[0013] In one embodiment, the bottom of the protrusion is an arc-shaped transition surface or a slope.

[0014] In one embodiment, the middle section surface of the inner tube includes a plurality of protrusions, which are arranged corresponding to the grooves of the support body.

[0015] In one embodiment, the flipping portion includes the protrusion to engage with the groove.

[0016] The aforementioned radiotherapy stent, by incorporating a sealing plug and a covering membrane, achieves a seal at the outlet of the cavity containing radioactive materials, thus avoiding leakage problems caused by damage to the stent body or excessive bending. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a radiotherapy stent in related technologies;

[0018] Figure 2 This is a side view of the hollow tube of the radiotherapy stent before heat shaping in one embodiment of the present invention.

[0019] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0020] Figure 4 for Figure 2 A schematic diagram of a radiotherapy stent placed within a tissue channel, as described in the embodiment;

[0021] Figure 5 This is a side view of the hollow tube of the radiotherapy stent before heat shaping, according to another embodiment of the present invention.

[0022] Figure 6 for Figure 5 A magnified view of a section at point B in the middle;

[0023] Figure 7 for Figure 5 A magnified view of a section at point C;

[0024] Figure 8 for Figure 5 A schematic diagram of a radiotherapy stent placed within a tissue channel, as described in the embodiment;

[0025] Figure 9 This is a side view of the hollow tube of the radiotherapy stent before heat shaping in another embodiment of the present invention.

[0026] Figure 10 for Figure 9 A magnified view of a section at point D;

[0027] Figure 11 for Figure 9 A schematic diagram of a radiotherapy stent placed within a tissue channel, as described in the embodiment;

[0028] Figure 12 This is a side view of the hollow tube of the radiotherapy stent before heat shaping in another embodiment of the present invention.

[0029] Figure 13 for Figure 12 A magnified view of a section at point E in the middle;

[0030] Figure 14 for Figure 12 A schematic diagram of a radiotherapy stent placed within a tissue channel, as described in the embodiment;

[0031] Figure 15 This is a cross-sectional schematic diagram of the structure of the radiotherapy stent in another embodiment of the present invention;

[0032] Figure 16 for Figure 15 A schematic diagram showing the positions of the radiotherapy stent body and inner tube in the embodiment;

[0033] Figure 17 This is a cross-sectional schematic diagram of the sealing plug of the radiotherapy stent in another embodiment of the present invention;

[0034] Figure 18 for Figure 17 A cross-sectional schematic diagram of the structure of the radiotherapy stent in the embodiment;

[0035] Figure 19 This is a schematic diagram of the inner tube of the radiotherapy stent in another embodiment of the present invention;

[0036] Figure 20 for Figure 19 A cross-sectional schematic diagram of the middle section of the radiotherapy stent in the embodiment.

[0037] Figure label:

[0038] Organize pipeline 100;

[0039] Radiotherapy stent 200, stent body 210, groove 211, first region 212, second region 213, connecting plug head 220, sealing plug head 230, baffle 2301, auxiliary baffle 2302, protrusion 2303, transition surface 2304, covering membrane 240, inner tube 250, flipping part 2501, protrusion 2502. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] See Figure 1 In related technologies, radiotherapy stents include a stent body 210, a connecting plug 220, and a sealing plug 230. One end of the stent body 210 is connected to the connecting plug 220, and the other end is connected to the sealing plug 230. (See also...) Figure 4 , Figure 8 , Figure 11 and Figure 14The radiotherapy stent 200 of this application can be placed within a tissue conduit 100, which is the conduit where a tumor or lesion is located or the conduit closest to the tumor. The radiotherapy stent 200 includes a stent body 210, which elastically abuts against the wall of the tissue conduit 100. The stent body 210 includes a helical structure and a hollow tube. The lumen of the hollow tube is used to contain radioactive material, and the outer circumferential surface of the hollow tube has a radially recessed groove 211. Specifically, the hollow tube is heat-formed and bent to form a helical stent body 210. The hollow tube is made of shape memory alloy, and after being heat-formed into the stent body 210, it has a certain degree of elasticity. After being inserted into the tissue conduit 100, it can abut against the wall of the tissue conduit 100 through its own elastic rebound force, thereby stably remaining at the lesion site. The lumen of the hollow tube carries radioactive material, which can be used to perform radiotherapy on the lesion site. After treatment, the radiotherapy stent 200 can be retrieved and removed from the body using a retrieval device. The aforementioned radiotherapy stent 200, by providing radially inwardly recessed grooves 211 on the outer circumferential surface of the hollow tube, can increase the flexibility of the hollow tube, making the deformation resistance during bending and deformation processes smaller, easier to shape, and less difficult to shape.

[0047] See Figure 4 , Figure 8 and Figure 11 In some embodiments, the groove 211 extends spirally on the outer circumferential surface of the hollow tube to form a spiral groove. Because the spiral groove, which is concave inward along the radial direction of the hollow tube, is provided on the outer circumferential surface of the hollow tube, the flexibility of the hollow tube can be increased, reducing deformation resistance during bending and deformation, making it easier to shape and reducing the difficulty of shaping. Simultaneously, because the groove 211 extends spirally, the different areas within the spiral groove pull and restrict each other along the axial direction of the hollow tube, increasing the support strength of the hollow tube for the wall of the tissue channel 100 when it is placed in the tissue channel 100 after heat setting. This makes it less likely for the radiotherapy stent 200 to shift after being placed in the preset position within the tissue channel 100, ensuring stable maintenance of the radiotherapy stent in the preset position for radiotherapy.

[0048] For ease of description and understanding, in the following embodiments, the axis of the hollow tube is taken as the first axis, and the axis of the spiral support body 210 formed by heat-setting the hollow tube is taken as the second axis. That is to say, the axis in the first axis is the rotation center line extending along the hollow tube. When the hollow tube is in a straight line, the first axis and the second axis are in the same direction.

[0049] See Figure 4 and Figure 8 Specifically, in some embodiments, the first end of the spiral groove is close to one end of the hollow tube along the first axial direction, and the last end of the spiral groove is close to the other end of the hollow tube along the first axial direction. See also... Figure 4 and Figure 8 It is known that only a single spiral groove is provided on the hollow tube. This spiral groove is relatively long, extending from one axial end of the hollow tube to the other. The single spiral groove 211 provides good support strength to different areas of the hollow tube due to the mutual tension between the segments of the spiral groove. This increases the flexibility of the hollow tube while maintaining its support strength after shaping, ensuring that the radiotherapy stent 200 is not easily displaced after being placed in the preset position within the tissue channel 100, and can stably remain in the preset position for radiotherapy. Furthermore, only one groove needs to be cut when creating the groove 211, simplifying the operation.

[0050] See Figures 2 to 4 Preferably, in some embodiments, the cross-sectional perimeter of the hollow tube is L, and after the side of the hollow tube is unfolded, the distance between two adjacent segments of the spiral groove along the first axial direction is L1, where 0.1L < L1 < 0.2L; L1 / L = tanα1, 5° < α1 < 10°. Specifically, Figure 2 The diagram shows the side view of the hollow tube. The cross-sectional perimeter L of the hollow tube is the width of the rectangle in the side view, and the length of this rectangle is the first axial length of the hollow tube. In the view, the spiral groove comprises multiple segments spaced apart along the first axial direction. The distance between two adjacent segments along the first axial direction is L1. According to trigonometric functions, L1 / L = tanα1. Limiting the size of L1 within the above range avoids insufficient flexibility due to an excessively large L1 size, while also avoiding insufficient support strength after shaping due to an excessively small L1 size. This balances flexibility and post-shaping support strength, facilitating shaping and preventing displacement when placed within the tissue tube 100 after shaping. Limiting α1 within the aforementioned range avoids insufficient flexibility due to excessive angle. It also prevents excessive gaps from being stretched at the cut point during the shaping process when the hollow tube is bent into a spiral shape, which would be detrimental to the sealing of the radiotherapy stent 200. Furthermore, it avoids insufficient support strength after shaping due to excessively small angle, thus balancing its flexibility and support strength after shaping. This not only facilitates shaping but also prevents displacement when placed within the tissue channel 100 after shaping.

[0051] See Figures 5 to 8Preferably, in some embodiments, the spiral groove includes a first region 212 and a second region 213 alternately distributed along a first axial direction. After the side of the hollow tube is unfolded, the distance between two adjacent segments along the first axial direction in the first region 212 of the spiral groove is L4, and the distance between two adjacent segments along the first axial direction in the second region 213 of the spiral groove is L5, where L4 ≠ L5. Specifically, the density of different regions in the spiral groove varies along the first axial direction, which can be approximated as different pitches in different regions. Specifically, in the embodiment shown in the attached figure, the spiral groove in the first region 212 is a dense region with a smaller pitch, and the spiral groove in the second region 213 is a sparse region with a larger pitch. The first region 212 can greatly increase the flexibility of the hollow tube, making the deformation resistance of the hollow tube during bending deformation less, easier to shape, and easier to shape. The second region 213 can greatly increase the support strength of the hollow tube, making it less prone to displacement when placed in a preset position within the tissue channel 100 after shaping, and able to stably maintain itself in the preset position for radiotherapy. By alternating between dense and sparse areas, both flexibility and support strength after shaping can be taken into account. This not only facilitates shaping but also prevents displacement when placed within the tissue channel 100 after shaping.

[0052] See Figures 5 to 8 Preferably, in some embodiments, after the side of the hollow tube is unfolded, the dimension of the first region 212 along the first axial direction is L2, the dimension of the second region 213 along the first axial direction is L3, the perimeter of the cross-section of the hollow tube is L, and the hollow tube includes a plurality of abutting regions on the same side for abutting against the tube wall. Along the second axial direction, the dimension of two adjacent abutting regions along the first axial direction is L6; L2 + L3 = 0.5L6, 0.125L6 < L2 < 0.25L6, 0.25L6 < L3 < 0.375L6; L4 / L = tanα2, L5 / L = tanα3, 5° < α2 < α3 < 10°; 0.1L < L4 < L5 < 0.2L. Specifically, in Figure 8From the perspective shown, the multiple abutment areas are the areas on the hollow tube that abut against the upper wall of the tissue channel 100, or the multiple areas that abut against the lower wall of the tissue channel 100. In the second axial direction, the distance between two adjacent abutment areas along the first axial direction is L6, which can also be considered as the length of one revolution of the hollow tube during shaping. Limiting α2 and α3 within the above range avoids excessive angles leading to insufficient flexibility. Simultaneously, it prevents excessive gaps from being stretched at the cut point when the hollow tube is bent into a spiral shape during shaping, which would be detrimental to the sealing of the radiotherapy stent 200. At the same time, it avoids excessively small angles leading to insufficient support strength after shaping, thus balancing flexibility and post-shaping support strength. This not only facilitates shaping but also prevents displacement within the tissue channel 100 after shaping. Limiting L2 and L3 within the aforementioned range effectively balances flexibility and support strength. It avoids L3 being too large (i.e., the second region 213 accounting for too large a proportion), resulting in insufficient flexibility, and L3 being too small (i.e., the second region 213 accounting for too small a proportion), resulting in insufficient support strength after shaping. Simultaneously, it avoids L2 being too large (i.e., the first region 212 accounting for too large a proportion), resulting in insufficient support strength after shaping, and L2 being too small (i.e., the first region 212 accounting for too small a proportion), resulting in insufficient flexibility. This balances flexibility and post-shaping support strength, facilitating shaping and preventing displacement within the tissue channel 100 after shaping. Similarly, limiting L4 and L5 within the aforementioned range avoids L4 and L5 being too large, resulting in insufficient flexibility, and L4 and L5 being too small, resulting in insufficient support strength after shaping. This balances flexibility and post-shaping support strength, facilitating shaping and preventing displacement within the tissue channel 100 after shaping.

[0053] See Figures 9 to 11 In some embodiments, the hollow tube has a cross-sectional perimeter of L, and multiple spiral grooves are disposed on the outer circumferential surface of the hollow tube. Any two adjacent spiral grooves are staggered along the axial direction of the hollow tube and also staggered along the circumferential direction of the hollow tube, so that the multiple spiral grooves are arranged in a spiral pattern on the outer circumferential surface of the hollow tube. Specifically, each groove 211 is spiral-shaped, and multiple grooves 211 are arranged in a spiral pattern. Since each groove 211 is spiral-shaped, the flexibility of the hollow tube can be increased, making it easier to bend and deform. Since the multiple grooves 211 are independent of each other, the solid tube wall between adjacent grooves 211 can improve the supporting strength of the hollow tube, thus combining flexibility and supporting strength.

[0054] Preferably, in some embodiments, the dimension of the spiral groove in its extension direction is L7, where 2 / 3L < L7 < 3 / 4L. Limiting the dimension L7 within this range avoids excessive size leading to insufficient strength, thus reducing the risk of breakage during bending deformation; simultaneously, it avoids excessive size leading to insufficient flexibility and difficulty in bending deformation. Preferably, the adjacent groove walls of each groove 211 are smoothly transitioned by rounded corners to reduce stress concentration during bending deformation, making the hollow tube less prone to breakage. Furthermore, the width w1 of the groove 211, the spacing d1 between adjacent grooves 211 along the arrangement direction, and the angle α4 between the length direction of the groove 211 and the width direction of the unfolded side view can be adjusted during design according to actual needs to obtain appropriate flexibility and support strength.

[0055] Preferably, in some embodiments, the outer circumferential surface of the hollow tube is provided with multiple sets of spiral groove assemblies. Each spiral groove assembly includes multiple spiral grooves disposed on the outer circumferential surface of the hollow tube. In each spiral groove assembly, any two adjacent spiral grooves are offset along the axial direction of the hollow tube and also offset along the circumferential direction of the hollow tube, so that the multiple spiral grooves in the spiral groove assembly are arranged in a spiral pattern on the outer circumferential surface of the hollow tube. Adjacent sets of spiral groove assemblies are also offset along the circumferential direction of the hollow tube and along the axial direction of the hollow tube. Specifically, the multiple spirally arranged grooves 211 mentioned in the previous embodiment can be considered as one set of spiral groove assemblies. In some embodiments, following the manner of the aforementioned embodiments, an additional set of spiral groove assemblies is added, and both sets of spiral groove assemblies are offset along the first axial direction from the circumferential direction of the hollow tube. By providing two sets of spiral groove assemblies, the flexibility of the hollow tube can be further increased, making it easier to bend and deform. In other embodiments, the number of spiral groove assemblies can also be more than two sets.

[0056] See Figures 12 to 14 In some embodiments, the grooves 211 extend along the circumferential direction of the hollow tube, and multiple grooves 211 are arranged at intervals along the axial direction of the hollow tube. The circumferential extension of the grooves 211 significantly improves the flexibility of the hollow tube, making it easier to bend and deform. Simultaneously, since the multiple grooves 211 are independent of each other, the solid tube wall between adjacent grooves 211 can improve the supporting strength of the hollow tube, thus combining flexibility and supporting strength. Preferably, during bending deformation, the area where the grooves 211 are located is mostly on the inner side of the radiotherapy stent 200, i.e., the side that does not contact the tissue channel 100. When it bends and deforms, the grooves 211 increase its flexibility, accommodating greater deformation on the inner side. At the same time, the outer side of the radiotherapy stent 200 can be made as smooth as possible, reducing friction with the tissue channel 100 and reducing the risk of damaging the tissue channel 100.

[0057] Preferably, in some embodiments, along the extending direction of the groove 211, the axial dimension of the center position of the groove 211 is smaller than the axial dimension of the end positions of the groove 211. Specifically, the width of the center position of the groove 211 is smaller, and the width of the two ends is larger. During the bending deformation process of the hollow tube, the two ends of the groove 211 undergo a greater degree of torsion. Setting the size larger at these ends can better provide space for torsional deformation, allowing for smooth bending deformation. Preferably, the adjacent groove walls of each groove 211 are smoothly transitioned by rounded corners to reduce stress concentration during bending deformation, making the hollow tube less prone to breakage.

[0058] Preferably, in some embodiments, since the radiotherapy stent 200 is used to place radioactive material into the tissue channel 100, the radioactive material is injected into or placed into the hollow tube of the radiotherapy stent 200. The tube wall of the radiotherapy stent 200 is partially composed of insulating material and partially of penetrating material. Furthermore, since the groove 211 thins the wall thickness at its location, the groove 211 serves as a penetrating part for the radioactive material. Even further, the groove 211 is located on the outer peripheral surface of the radiotherapy stent 200 near its own axis (i.e., the second axial direction), i.e., on the inner side of the entire radiotherapy stent 200, to prevent the groove 211 from getting stuck in the tissue channel 100 or being too close to the tissue channel 100. Because the radiotherapy stent 200 extends along a spiral structure, the distance from the groove 211 to the tissue channel 100 it faces is always greater than the radius of the radiotherapy stent 200, thereby avoiding excessive irradiation of the tissue channel by the radioactive material.

[0059] Preferably, in some embodiments, the cross-sectional perimeter of the hollow tube is L, and the circumferential dimension of the groove 211 is L8, where 2 / 3L < L8 < 3 / 4L. Limiting the dimension L8 within this range avoids excessive size leading to insufficient strength, thereby reducing the risk of breakage during bending deformation; simultaneously, it avoids insufficient flexibility due to excessive size, making bending deformation difficult. Furthermore, the width w2 at the end position of the groove 211, the width w3 at the center position, and the spacing d2 between adjacent grooves 211 along the first axial direction can be adjusted during design according to actual needs to obtain appropriate flexibility and support strength.

[0060] As mentioned above, the lumen of the radiotherapy stent 200 carries radioactive material, which can be used to treat the lesion site with radiotherapy. After treatment, the radiotherapy stent 200 is retrieved and removed from the body using a retrieval device. Therefore, the radiotherapy stent 200 must ensure the airtightness of the lumen. However, when the multiple grooves in the hollow tube are penetrated or excessively bent, the hollow tube loses its airtightness. Therefore, it is necessary to seal the surface of the radiotherapy stent 200, as shown in the following embodiment:

[0061] See Figure 15-16Specifically, in some embodiments, the radiotherapy stent 200 includes a stent body 210, the surface of which is covered with a membrane 240. The membrane 240 is a polymer membrane, and the material is selected as PTFE or PET. It is generally covered on the surface of the stent 210 by heat fusion or bonding. However, since heat fusion and bonding cannot stably cover all grooves, the membrane 240 alone cannot meet the sealing standard of the radiotherapy stent 200. Therefore, an inner tube 250 is attached to the inner side of the stent body 210. The inside of the inner tube 250 serves as a cavity to carry the drug. The inner tube 250 is elastic. In the middle section of the stent body 210, the inner tube 250 is close to the inner wall of the stent body 210 and extends with the stent body 210 until it reaches the sealing plug 230. It should be noted that the connecting plug 220 is the same as the sealing plug 230 except for the connection structure. In this embodiment, the inner tube 250 covers the end of the stent body 210. Specifically, a portion of the inner tube 250 extends out of the interior of the stent body 210 and is flipped at the end of the stent body 210 to form a flipped portion 2501. The flipped portion 2501 covers a portion of the outer side of the stent body 210. With this arrangement, the end of the stent body 210 is completely covered by the inner tube 250 and the membrane 240. Combined with the setting of the sealing plug 230, the drug in the inner tube 250 will not directly leak out from the boundary of the stent body 210.

[0062] The sealing plug 230 includes a baffle 2301 facing the stent body 210. The baffle 2301 surrounds an opening facing the stent body 210 to seal the ends of the cover 240, the stent body 210, and the inner tube 250. It should be noted that the sealing plug 230 is removable to ensure that drugs can be injected or placed into the stent body 210.

[0063] Reference Figure 17-18Preferably, the baffle 2301 of the sealing bolt head 230 extends inward at its end to form an auxiliary baffle 2302, and the middle part of the sealing bolt head 230 protrudes towards the bracket body 210 to form a protrusion 2303, which is inserted into the interior of the inner tube 250. This structural design further improves the sealing performance. Specifically, when the filling is complete and the sealing plug 230 needs to be installed, a part of the inner tube 250 (i.e., the flipping part 2501) extends out of the support body. The flipping part 2501 is located outside the protrusion 2303. As the sealing plug 230 gradually approaches the support body 210, the protrusion 2303 gradually gets into the interior of the inner tube 250. The flipping part 2501 moves towards the bottom of the protrusion 2303 along with the protrusion 2501. When it reaches the bottom of the protrusion 2303, since the inner side of the flipping part 2501 is close to the protrusion 2303 and the outer side is unobstructed, the flipping part 2501 naturally flips outward with the installation of the sealing plug 230, thereby realizing the automatic flipping of the flipping part 2501. The auxiliary baffle 2302 is used to press against and seal the end of the flipping part 2501 to ensure the complete sealing of the inner tube 250. It should be noted that if the auxiliary baffle 2302 is not present, sealing and automatic flipping can still be achieved by relying on the protrusion 2303 and the baffle 2301, as long as the baffle 2301 can finally press against the flipping part 2501.

[0064] Preferably, the distance between the baffle 2301 and the support body 210 is slightly less than or equal to the thickness of the flipping part 2501.

[0065] Preferably, when the sealing plug head 230 is assembled, the auxiliary baffle 2302 is located between the end of the bracket body 210 and the groove 211 closest to the end.

[0066] Preferably, the bottom transition surface 2304 of the protrusion 2303 is an arc-shaped transition surface or a slope, ensuring that the flipping part 2501 moves in a direction that gradually flips outward until the final flip is achieved.

[0067] Preferably, the inner tube 250 is made of self-curing medical liquid silicone. First, the mold rod is passed through the inner cavity of the stent body 210, and then the liquid silicone is injected to fill the gap between the stent body 210 and the mold rod.

[0068] Reference Figure 17-18 Preferably, the middle section surface of the inner tube 250 is provided with a plurality of protrusions 2502 corresponding to the grooves 211. The protrusions 2502 are provided corresponding to the grooves 211 of the support body 210 and are finally inserted into the grooves 211 of the support body 210 to achieve relative fixation between the inner tube 250 and the support body 210.

[0069] Preferably, the flipping part 2501 can also be configured with a partial protrusion to fit into the interior of the groove 211 to form a better sealing effect.

[0070] 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.

[0071] 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 support, characterised in that, include: The stent body is elastically supported against the wall of a tissue duct. The stent body includes a hollow tube, the lumen of which forms an inner cavity for containing radioactive materials. The outer surface of the hollow tube is provided with a groove that is recessed radially along the hollow tube. The hollow tube is bent and deformed to form a spiral stent body. A sealing plug head, which is detachably disposed at the outlet position of the inner cavity to close or open the outlet; The inner tube covers the inner wall of the inner cavity and is made of self-curing medical liquid silicone. The interior of the inner tube serves as a cavity to hold the drug. The middle section surface of the inner tube includes multiple protrusions, which are arranged to correspond to the grooves of the hollow tube.

2. The radiotherapy stent of claim 1, wherein, A portion of the inner tube extends out of the support body and flips at the end of the support body to form a flipped portion, which at least covers a portion of the outer side of the support body.

3. The radiotherapy stent of claim 2, wherein, The sealing plug includes a baffle facing the support body, the baffle forming an opening facing the support body to seal the inner cavity.

4. The radiotherapy stent of claim 3, wherein, An auxiliary baffle extends inward from the end of the baffle, and the auxiliary baffle abuts against the film disposed on the outer surface of the support body, the support body, or the flipping part.

5. The radiotherapy stent according to claim 3, characterized in that, The middle part of the sealing plug protrudes towards the bracket body to form a protrusion, which is inserted into the interior of the inner tube, and the flipping part is located on the outside of the protrusion.

6. The radiotherapy stent according to claim 3, characterized in that, The distance between the baffle and the main body of the support is less than or equal to the thickness of the flipping part.

7. The radiotherapy stent according to claim 4, characterized in that, The auxiliary baffle is located between the end of the support body and the groove closest to the end.

8. The radiotherapy stent according to claim 5, characterized in that, The bottom of the protrusion is an arc-shaped transition surface or a slope.

9. The radiotherapy stent according to any one of claims 2-8, characterized in that, It also includes a coating, which is disposed on the outer surface of the support body.

10. The radiotherapy stent according to claim 9, characterized in that, The flipping portion includes the protrusion to engage with the groove.

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