WO2023125905A1

WO2023125905A1 - Radiotherapy stent

Info

Publication number: WO2023125905A1
Application number: PCT/CN2022/143830
Authority: WO
Inventors: 黄旺兴; 刘彩萍; 肖本好
Original assignee: 先健科技(深圳)有限公司
Priority date: 2021-12-31
Filing date: 2022-12-30
Publication date: 2023-07-06

Abstract

A radiotherapy stent (200), comprising a stent main body (210), the stent main body (210) being capable of elastically abutting against a wall of a tissue tract (100), and the stent main body (210) comprising an inner cavity for accommodating radioactive substances; and the radiotherapy stent (200) further comprising a sealing bolt head (230), the sealing bolt head (230) being detachably provided at an outlet position of the inner cavity to close or open the outlet. By providing the sealing bolt head (230) and a covering membrane (240), the radiotherapy stent (200) can seal the outlet of the inner cavity for accommodating radioactive substances, avoiding the problem of leakage caused by damage or excessive bending of the stent main body (210).

Description

radiotherapy stent

related application

This application requires a Chinese patent application filed on December 31, 2021 with the application number 2021116787708 titled "Radiation Therapy Stent" and an application filed on December 31, 2021 with the application number 2021116787110 named "Radiation Therapy Stent and Recovery System" ", the priority of the Chinese patent application, which is hereby incorporated by reference in its entirety.

technical field

The invention relates to the technical field of interventional medical equipment, in particular to a radiotherapy bracket.

Background technique

In recent years, the incidence of cancer has shown an obvious upward trend. At present, about 70% of patients need radiotherapy during cancer treatment, and about 40% of patients can be cured through radiotherapy. This makes radiotherapy an important role in cancer treatment. The role and status of China has become increasingly prominent. At present, there is a more precise radiation therapy in the industry, which can minimize the damage caused by radiation therapy to human healthy tissues. This method is to place radioactive substances in the radiotherapy stent and send the radiotherapy stent to the diseased part of the patient's body, so as to treat the diseased tissue in a targeted manner, especially for the treatment of cavity cancers such as esophageal cancer and biliary tract cancer. . This type of radiotherapy stent is usually in the form of a spring, which can elastically resist against the wall of the human tissue pipeline after being delivered to the lesion, so as to resist displacement. When manufacturing radiotherapy stents, it is generally by heat-setting the tubing to make it into the desired spring pattern. However, in the related art, the structure of some radiotherapy stents determines that it is difficult to shape during the heat setting process. The present invention mentions a way to reduce the difficulty of shaping by setting grooves. However, the lumen of the radiotherapy stent Carrying radioactive substances, radiation therapy can be performed on the lesion. After the treatment is over, the radiotherapy stent is recovered by the recovery device and taken out of the body. Therefore, the radiotherapy stent must ensure the sealing of the lumen. However, the multiple concave holes on the main body of the stent When the groove is penetrated, that is, when the main body of the stent is damaged, or the stent is excessively bent, the stent will lose its airtightness. Therefore, the surface of the radiotherapy stent needs to be sealed.

Contents of the invention

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

Radiation therapy stents, including:

A stent main body, the stent main body can elastically resist the tube wall of the tissue duct, and the stent main body includes an inner cavity for accommodating radioactive substances;

A sealing plug head is detachably arranged at the outlet of the inner cavity to close or open the outlet.

In one of the embodiments, the radiotherapy stent further includes an inner tube covering the inner wall of the lumen, a part of the inner tube protrudes from the stent main body, and is turned over at the end of the stent main body to form an inverted portion , the turning portion covers at least a part of the outer side of the stent main body.

In one of the embodiments, the sealing plug head includes the baffle facing the stent body, and the baffle surrounds the opening facing the stent body to seal the inner cavity.

In one of the embodiments, the end of the baffle protrudes inwardly from an auxiliary baffle, and the auxiliary baffle is against the covering film or the stent main body or the turning portion.

In one of the embodiments, the middle part of the sealing plug head protrudes toward the main body of the bracket to form a protrusion, the protrusion snaps into the inner tube, and the turning part is located on the protrusion outside.

In one of the embodiments, the distance between the baffle plate and the bracket body is smaller than or equal to the thickness of the turning portion.

In one embodiment, the auxiliary baffle is located between the end of the bracket body and the groove closest to the end.

In one embodiment, the surface of the middle section of the inner tube includes a plurality of protrusions, and the protrusions are arranged corresponding to the grooves of the bracket body.

In one of the embodiments, the turning part includes the protrusion to be snapped into the groove.

In one of the embodiments, the stent body includes a connected drug-loaded section and a supporting section, the stent body also includes an unstressed natural state and a stressed compressed state, and the drug-loaded section includes a A lumen of a substance, at least the proximal end of the stent body extends along the axis in a natural state, the support section includes a helical structure, the drug-loaded section is connected to the support section and is located at the axis of the stent body Or located on one side of the axis of the stent main body.

In one of the embodiments, the stent body includes multiple drug-loaded segments and multiple support segments, at least one drug-loaded segment is located between two adjacent support segments.

In one of the embodiments, the distal end and the proximal end of each of the drug-loading segments have the support segments.

In one of the embodiments, the supporting section includes a helical section and a transition section, the transition section extends in the axial direction, and the transition section connects two adjacent helical sections.

In one embodiment, two adjacent transition sections are distributed along the circumferential direction and parallel to each other.

In one of the embodiments, the transition section includes an anchoring enhancement structure.

The above-mentioned radiotherapy stent realizes the sealing of the outlet of the inner cavity containing radioactive substances by setting the sealing plug head and the covering film, and avoids the leakage problem caused by the main body of the stent being damaged or excessively bent.

Description of drawings

Fig. 1 is the structural representation of radiotherapy stent in the related art;

Fig. 2 is a schematic diagram of side expansion of the hollow tube before heat setting of the radiotherapy stent in an embodiment of the present invention;

Fig. 3 is a partial enlarged view of place A in Fig. 2;

Fig. 4 is the schematic diagram that the radiotherapy stent of Fig. 2 embodiment is placed in the tissue channel;

Fig. 5 is a side view of the hollow tube before heat setting of the radiotherapy stent in another embodiment of the present invention;

Fig. 6 is a partial enlarged view of place B in Fig. 5;

Fig. 7 is a partial enlarged view of place C in Fig. 5;

Fig. 8 is a schematic diagram of placing the radiotherapy stent in the embodiment of Fig. 5 in the tissue channel;

Fig. 9 is a schematic diagram of side development of the hollow tube before heat setting of the radiotherapy stent in another embodiment of the present invention;

Figure 10 is a partial enlarged view at D in Figure 9;

Fig. 11 is a schematic diagram of placing the radiotherapy stent in the embodiment of Fig. 9 in the tissue channel;

Fig. 12 is a schematic diagram of side expansion of the hollow tube before heat setting of the radiotherapy stent in another embodiment of the present invention;

Figure 13 is a partial enlarged view at E in Figure 12;

Fig. 14 is a schematic diagram of placing the radiotherapy stent in the embodiment of Fig. 12 in the tissue channel;

15 is a schematic cross-sectional view of the structure of a radiotherapy stent in another embodiment of the present invention;

Fig. 16 is a schematic diagram of the positions of the stent body and the inner tube of the radiotherapy stent in the embodiment of Fig. 15;

Fig. 17 is a schematic cross-sectional view of the sealing plug head of the radiotherapy stent in another embodiment of the present invention;

Fig. 18 is a schematic cross-sectional view of the structure of the radiotherapy stent in the embodiment of Fig. 17;

Fig. 19 is a schematic structural view of the inner tube of the radiotherapy stent in another embodiment of the present invention;

Fig. 20 is a schematic cross-sectional view of the middle section of the radiotherapy stent in the embodiment of Fig. 19;

Fig. 21 is a schematic diagram of a radiotherapy stent placed in a human tissue pipeline (straight tube) in an embodiment of the present invention;

Fig. 22 is a schematic diagram of a radiotherapy stent placed in a human tissue pipeline (straight tube) in another embodiment of the present invention;

Fig. 23 is a schematic diagram of a radiotherapy stent placed in a human tissue pipeline (straight tube) in another embodiment of the present invention;

Fig. 24 is a schematic diagram of a radiotherapy stent placed in a human tissue duct (straight duct) in another embodiment of the present invention.

Reference signs:

tissue pipeline 100;

Radiotherapy stent 200, stent body 210, drug-loading section 2101, support section 2102, helical section 2103, transition section 2104, wave section 2105, groove 211, first area 212, second area 213, connecting plug head 220, sealing plug Head 230 , baffle 2301 , auxiliary baffle 2302 , protruding portion 2303 , transition surface 2304 , coating 240 , inner tube 250 , turning portion 2501 , and protrusion 2502 .

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, specific implementations of the present invention will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or Elements must have certain orientations, be constructed and operate in certain orientations, and therefore should not be construed as limitations on the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions are for the purpose of illustration only and are not intended to represent the only embodiments.

Referring to FIG. 1 , in the related art, a radiotherapy stent includes 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 . Referring to Fig. 4, Fig. 8, Fig. 11 and Fig. 14, the radiotherapy stent 200 in the present application can be placed in the tissue duct 100, the tissue duct 100 is the duct where the tumor or lesion is located or the duct closest to the tumor position, the radiotherapy stent 200 Including a stent body 210, the stent body 210 can elastically resist the tube wall of the tissue channel 100, the stent body 210 includes a helical structure, the stent body 210 includes a hollow tube, the lumen of the hollow tube is used to accommodate radioactive substances, and the outer peripheral surface of the hollow tube A groove 211 recessed along the radial direction of the hollow tube is provided. Specifically, the hollow tube is bent and deformed by heat setting to form a helical stent body 210 . The hollow tube is made of shape memory alloy, which has a certain degree of elasticity after being heat-set into the stent main body 210. After being sent into the tissue tube 100, it can be held against the tube wall of the tissue tube 100 by its own elastic resilience, thereby stabilizing remain at the lesion site. The lumen of the hollow tube carries radioactive substances, which can be used to treat the lesion with radiation. After the treatment is finished, the radiotherapy stent 200 can be recovered by the recovery device and taken out from the body. The above-mentioned radiotherapy support 200 can increase the flexibility of the hollow tube by providing a radially inwardly recessed groove 211 on the outer peripheral surface of the hollow tube, so that the deformation resistance of the hollow tube during bending deformation is smaller, and it is easier to shape and shape Less difficult.

Referring to FIG. 4 , FIG. 8 and FIG. 11 , in some embodiments, the groove 211 extends helically on the outer peripheral surface of the hollow tube to form a helical groove. Since the outer peripheral surface of the hollow tube is provided with a spiral groove that is sunken inward along the radial direction of the hollow tube itself, the flexibility of the hollow tube can be increased, and the deformation resistance of the hollow tube during bending deformation is smaller, making it easier to shape and more difficult to shape. Low. At the same time, since the groove 211 extends in a helical shape, in the axial direction of the hollow tube, different areas in the helical groove are mutually pulled and restricted, which can increase the stability of the hollow tube when it is placed in the tissue canal 100 after heat setting. The support strength of the wall makes it difficult for the radiotherapy support 200 to shift after being placed in the preset position in the tissue duct 100, and can be stably maintained at the preset position for radiotherapy.

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 helical stent body 210 formed by heat setting of the hollow tube is taken as the second axis, that is, In other words, the axis in the first axis is the centerline of rotation extending along the hollow tube, and when the hollow tube is in a straight state, the first axis and the second axis are in the same direction.

Referring to Fig. 4 and Fig. 8, specifically, in some embodiments, the head end of the helical groove is close to one end of the hollow tube along the first axis, and the tail end of the helical groove is close to the other end of the hollow tube along the first axis. Referring to Fig. 4 and Fig. 8, it can be seen that only a single helical groove is provided on the hollow tube, and the length of the helical groove is relatively large, and can basically extend from one axial end of the hollow tube to the other axial end. Setting a single helical groove 211 can make each area on the hollow tube have better support strength due to the mutual pull between the sections of the helical groove, so as to increase the flexibility of the hollow tube while taking into account the support strength after shaping , so that the radiotherapy stent 200 is not easy to shift after being placed in the preset position in the tissue duct 100, and can be stably maintained at the preset position for radiotherapy. And when cutting out the groove 211, only one groove needs to be cut out, and the operation is also simpler.

Referring to Fig. 2 to Fig. 4, preferably, in some embodiments, the cross-sectional perimeter of the hollow tube is L, and after the side of the hollow tube is expanded, in the first axial direction, the adjacent two sections of the helical groove are along the first axis. The axial distance is L ₁ , 0.1L<L ₁ <0.2L; L ₁ /L=tanα ₁ , 5°<α ₁ <10°. Specifically, Fig. 2 is a side development view of the hollow tube, the cross-sectional perimeter L of the hollow tube is the width of the rectangle in the side development view, and the length of the rectangle is the first axial length of the hollow tube. In the unfolded view, the helical groove includes multiple sections spaced apart along the first axis, and the distance between two adjacent sections along the first axis is L ₁ . According to trigonometric functions, L ₁ /L=tanα ₁ . Limiting the size of _L1 to the above range can avoid insufficient flexibility caused by too large a size of _L1 , and at the same time avoid insufficient support strength after setting because of a too small size of _L1 , so as to take into account its flexibility and support strength after setting, not only It is convenient for shaping, and it is not easy to shift after being placed in the tissue channel 100 after shaping. Limiting α ₁ within the above range can avoid insufficient flexibility caused by too large angle, and at the same time, it can also avoid that when the hollow tube is bent into a helical shape during the shaping process, the cutting part will be stretched out to a large gap, which is not conducive to radiotherapy The sealing of the bracket 200; in addition, it can avoid the insufficient support strength after shaping due to too small angle, so as to give consideration to its flexibility and support strength after shaping, which is not only convenient for shaping, but also difficult to shift when placed in the tissue channel 100 after shaping.

Referring to Fig. 5 to Fig. 8, preferably, in some embodiments, the helical groove includes first regions 212 and second regions 213 alternately distributed along the first axis, and after the side of the hollow tube is expanded, in the first axis direction , the distance between two adjacent sections along the first axis in the first area 212 of the spiral groove is L ₄ , the distance between two adjacent sections along the first axis in the second area 213 of the spiral groove is L ₅ , L ₄ ≠ _L5 . Specifically, along the first axis, different regions in the helical groove have different densities, and it can be approximately considered that the pitches of different regions are different. Specifically, in the embodiment shown in the drawings, the helical groove is a dense region with a small pitch in the first region 212 , and the helical groove is a sparse region with a relatively large pitch in the second region 213 . Wherein, the first region 212 can increase the flexibility of the hollow tube to a large extent, so that the deformation resistance of the hollow tube during the bending deformation process is smaller, which is easier to shape and less difficult to shape. The second region 213 can greatly increase the support strength of the hollow tube, making it less likely to shift when it is placed in the preset position in the tissue duct 100 after being shaped, and can be stably kept at the preset position for radiotherapy. By alternating density and density, both flexibility and support strength after shaping can be taken into account, which is not only convenient for shaping, but also difficult to shift when placed in the tissue channel 100 after shaping.

5 to 8, preferably, in some embodiments, after the side of the hollow tube is expanded, the dimension of the first region 212 along the first axis is L ₂ , and the dimension of the second region 213 along the first axis is L ₃ , the cross-sectional perimeter of the hollow tube is L, the hollow tube includes a plurality of abutting areas on the same side of the tube wall, and in the second axial direction, two adjacent abutting areas One axial dimension is L ₆ ; L ₂ +L ₃ =0.5L ₆ , 0.125L ₆ <L ₂ <0.25L ₆ , 0.25L ₆ <L ₃ <0.375L ₆ ; L ₄ /L=tanα ₂ , L ₅ /L=tanα ₃ , 5°<α ₂ <α ₃ <10°;0.1L<L ₄ <L ₅ <0.2L. Specifically, from the perspective shown in FIG. 8 , the multiple resisting areas are the multiple areas on the hollow tube that are against the upper tube wall of the tissue channel 100, or the multiple areas that are against the lower tube wall of the tissue channel 100. . In the second axial direction, the distance between two adjacent resisting areas along the first axial direction is L ₆ , which can also be considered as the length of one rotation of the hollow tube when it is bent _and shaped. Limiting α ₂ and α ₃ within the above range can avoid insufficient flexibility caused by too large angle, and at the same time, it can also avoid the excessive gap caused by stretching out the cutting part when the hollow tube is bent into a spiral shape during the shaping process. It is not conducive to the sealing of the radiotherapy stent 200; at the same time, it can avoid the insufficient support strength after shaping due to too small angle, so as to take into account its flexibility and support strength after shaping, which is not only convenient for shaping, but also difficult to move when placed in the tissue channel 100 after shaping bit. Limiting L ₂ and L ₃ within the above-mentioned range can better balance the flexibility and support strength, and avoid insufficient flexibility caused by too large L ₃ (that is, the proportion of the second region 213 is too large), and avoid too small L ₃ (that is, The proportion of the second area 213 is too small), resulting in insufficient support strength after shaping; while avoiding L ₂ being too large (that is, the proportion of the first area 212 is too large), resulting in insufficient support strength after shaping, and avoiding L ₂ being too small (that is, the first area 212 The proportion of the first area 212 is too small), resulting in insufficient flexibility, so as to give consideration to its flexibility and support strength after shaping, which is not only convenient for shaping, but also difficult to shift when placed in the tissue channel 100 after shaping. Limiting L ₄ and L ₅ within the above range can avoid insufficient flexibility caused by excessive size of L ₄ and L ₅ , and at the same time avoid insufficient support strength after shaping due to too small size of L ₄ and L ₅ , thus taking into account its flexibility and The support strength after shaping is not only convenient for shaping, but also difficult to shift when placed in the tissue channel 100 after shaping.

Referring to Figures 9 to 11, in some embodiments, the cross-sectional circumference of the hollow tube is L, a plurality of helical grooves are provided on the outer peripheral surface of the hollow tube, and any two adjacent helical grooves are along the axial direction of the hollow tube. Staggered, and any two adjacent helical grooves are staggered along the circumferential direction of the hollow tube itself, so that a plurality of helical grooves are helically arranged at intervals on the outer peripheral surface of the hollow tube. Specifically, each groove 211 is in a spiral shape, and a plurality of grooves 211 are arranged in a spiral shape. Because each groove 211 is helical, the flexibility of the hollow tube can be increased, making it easy to bend and deform. Since multiple grooves 211 are independent of each other, the solid tube wall between adjacent grooves 211 can improve the hollow tube. Support strength, so as to have both flexibility and support strength.

Preferably, in some embodiments, the dimension of the spiral groove in its own extension direction is L ₇ , 2/3L<L ₇ <3/4L. Limiting the size of L ₇ within the above range can avoid insufficient strength due to excessive size, thereby reducing the risk of breaking during bending deformation; at the same time, avoid insufficient flexibility and difficulty in bending deformation due to too small size. Preferably, the adjacent groove walls of each groove 211 have a smooth transition through rounded corners, so as to reduce the stress concentration during bending deformation, so that the hollow tube is not easy to break. In addition, the width w1 of the grooves 211, the distance d1 between adjacent grooves 211 along the arrangement direction, and the angle α ₄ between the length direction of the grooves 211 and the width direction of the side development view can also be adjusted according to actual needs during design, so that Get the right amount of flexibility and support strength.

Preferably, in some embodiments, the outer peripheral surface of the hollow tube is provided with multiple sets of helical groove assemblies, and the helical groove assembly includes a plurality of helical grooves arranged on the outer peripheral surface of the hollow tube. Among the helical groove assemblies, any adjacent two The spiral grooves are staggered along the hollow tube's own axial direction, and any two adjacent spiral grooves are staggered along the hollow tube's own circumferential direction, so that a plurality of spiral grooves in the spiral groove assembly are arranged in a helical interval on the outer periphery of the hollow tube Surface; two adjacent sets of spiral groove assemblies are staggered along the hollow tube's own circumferential direction, and two adjacent sets of spiral groove assemblies are staggered along the hollow tube's own axial direction. Specifically, the multiple grooves 211 arranged in a spiral shape mentioned in the previous embodiment can be regarded as a set of spiral groove components. In some embodiments, a set of spiral grooves is added according to the method of the previous embodiment Assemblies, two sets of helical groove assemblies are staggered along the first axis and the circumferential direction of the hollow tube itself. By arranging two sets of helical groove components, 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 components can also be more than two groups.

Referring to FIG. 12 to FIG. 14 , in some embodiments, the groove 211 extends along the circumferential direction of the hollow tube, and a plurality of grooves 211 are arranged at intervals along the axial direction of the hollow tube. The groove 211 extends along the circumferential direction of the hollow tube, which can greatly improve the flexibility of the hollow tube and make it easy to bend and deform. At the same time, since the plurality of 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 having both flexibility and supporting strength. Preferably, when bending and deforming, the area where the groove 211 is located is mostly located on the inner side of the radiotherapy support 200, that is, the side that is not in contact with the tissue pipeline 100. When it is bent and deformed, the groove 211 is used to increase its flexibility and adapt to the inner side greater degree of deformation. At the same time, the outer side of the radiotherapy support 200 can be made as smooth as possible, which can reduce the friction with the tissue pipeline 100 and reduce the risk of damaging the tissue pipeline 100 .

Preferably, in some embodiments, along the extending direction of the groove 211 , the axial dimension of the center of the groove 211 is smaller than the axial dimension of the end of the groove 211 . Specifically, the width at the center of the groove 211 is smaller, and the width at both ends is larger. During the bending and deformation process of the hollow tube, the two ends of the groove 211 are torsion to a greater extent, setting the size here to be larger can better provide a space for torsional deformation and make it bend and deform smoothly. Preferably, the adjacent groove walls of each groove 211 have a smooth transition through rounded corners, so as to reduce the stress concentration during bending deformation, so that the hollow tube is not easy to break.

Preferably, in some embodiments, since the radiotherapy stent 200 is used to place radioactive substances into the tissue duct 100, and the radioactive substances are injected or put into the hollow tube of the radiotherapy stent 200, for the tube wall of the radiotherapy stent 200, it is set Part is an insulating material, and part is a penetrating material. Further, because the groove 211 will reduce the wall thickness of its location, the position of the groove 211 is used as the penetration part of the radioactive material. Further, the groove 211 It is arranged on the side of the outer peripheral surface of the radiotherapy stent 200 close to its own axis (ie, the second axial direction), that is, the inner side of the radiotherapy stent 200 as a whole, so as to prevent the groove 211 from being caught in the tissue channel 100 or too close to the tissue channel 100 . Since the radiotherapy stent 200 extends along a helical structure, the distance from the groove 211 to the tissue channel 100 facing it is always greater than the radius of the radiotherapy stent 200 , thereby avoiding excessive irradiation of radioactive substances on the tissue channel.

Preferably, in some embodiments, the circumference of the cross section of the hollow tube is L, the dimension of the groove 211 along the circumference is L ₈ , and 2/3L<L ₈ <3/4L. Limiting the size of L ₈ within the above range can avoid insufficient strength due to excessive size, thereby reducing the risk of breaking during bending deformation; at the same time, avoid insufficient flexibility and difficulty in bending deformation due to too small size. In addition, the width w2 at the end position of the groove 211, the width w3 at the center position, and the distance d2 between adjacent grooves 211 along the first axial direction can also be adjusted according to actual needs during design, so as to obtain appropriate flexibility and support strength .

As mentioned above, the lumen of the radiotherapy stent 200 carries radioactive substances, which can perform radiotherapy on the lesion. After the treatment is completed, the radiotherapy stent 200 will be recovered and taken out of the body through a recovery device. Therefore, the radiotherapy stent 200 must ensure that the tube However, when the multiple grooves in the upper hollow tube are penetrating, or in the case of excessive bending, the hollow tube loses its airtightness. Therefore, the surface of the radiotherapy support 200 needs to be sealed. , with specific reference to the following examples:

Referring to Figures 15-16, specifically, in some embodiments, the radiotherapy stent 200 includes a stent body 210, the surface of the stent body 210 is provided with a coating 240, the coating 240 is a polymer film, and the material is PTFE or PET. The surface of the stent 210 is covered by heat-melting or bonding, but because the heat-melting and bonding cannot cover all the grooves stably, the simple coating 240 cannot reach the sealing standard of the radiotherapy stent 200. Therefore, in the stent main body An inner tube 250 is attached to the inner side of the stent 210. The inner tube 250 is used as a cavity to carry drugs. The inner tube 250 is elastic. , until reaching the position of the sealing plug head 230, it should be noted that, except that the connection structure of the connecting plug head 220 is different from that of the sealing plug head 230, the principle of sealing is the same. In this embodiment, the inner tube 250 covers the end of the stent main body 210, specifically, a part of the inner tube 250 protrudes from the inside of the stent main body 210, and is turned over at the end of the stent main body 210 to form a turning portion 2501. The turning portion 2501 Covering a part of the outside of the stent main body 210, after setting in this way, the end of the stent main body 210 is completely covered by the inner tube 250 and the covering film 240, combined with the setting of the sealing plug head 230, so that the medicine in the inner tube 250 will not come from The border of the stent body 210 oozes directly.

The sealing plug 230 includes a baffle 2301 facing the stent main body 210, and the baffle 2301 surrounds and forms an opening facing the stent main body 210 to seal the end of the membrane 240, the stent main body 210, and the inner tube 250. It should be noted that the sealing The plug head 230 is detachable to ensure that medicine can be injected or put into the stent main body 210 .

17-18, preferably, the baffle 2301 of the sealing plug head 230 protrudes inward at its end to form an auxiliary baffle 2302, and the middle part of the sealing plug head 230 protrudes toward the bracket main body 210 to form a protrusion 2303 , the protrusion 2303 snaps into the interior of the inner tube 250 . Such a structural setting can further improve the sealing performance. Specifically, when the charge is completed and the sealing plug 230 needs to be installed, since a part of the inner tube 250 (that is, the inverting portion 2501) protrudes from the main body of the stent, the inverting portion 2501 is located at the protruding position. Outside the outer part 2303, as the sealing plug head 230 gradually approaches the bracket body 210, the protruding part 2303 gradually snaps into the inner tube 250, and the turning part 2501 is close to the protruding part 2501 toward the bottom of the protruding part 2303. When the bottom of the part 2303 is out, since the inside of the turning part 2501 is close to the protruding part 2303, and the outside is not blocked, the turning part 2501 will naturally turn outwards along with the sealing plug head 230, thus realizing the turning part 2501. automatic overturning, and the auxiliary baffle 2302 is used to press against and seal the end of the overturning part 2501 to ensure that the inner tube 250 is completely sealed. It should be noted that if there is no auxiliary baffle 2302 , sealing and automatic turning can still be achieved by relying on the protruding portion 2303 and the baffle 2301 , as long as the baffle 2301 can finally abut against the turning portion 2501 .

Preferably, the distance between the baffle plate 2301 and the bracket body 210 is slightly smaller than or equal to the thickness of the turning portion 2501 .

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

Preferably, the bottom transition surface 2304 of the protruding part 2303 is an arc transition surface or an inclined surface, which ensures that the turning part 2501 moves along the direction of gradually turning outward until the final turning is realized.

Preferably, the inner tube 250 is made of self-curing medical liquid silicone, and the mold stick 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 stick.

19-20, preferably, the middle surface of the inner tube 250 is provided with a plurality of protrusions 2502 corresponding to the grooves 211, the protrusions 2502 are set corresponding to the grooves 211 of the bracket body 210, and finally snap into the grooves of the bracket body 210. inside the groove 211 to realize the relative fixing of the inner tube 250 and the bracket body 210 .

Preferably, the inverting portion 2501 can also be provided with a part of a protrusion to snap into the inside of the groove 211 to form a better sealing effect.

As mentioned above, when the radiotherapy stent 200 is implanted into the human body, the stent body 210 includes a cavity for accommodating radioactive substances. Generally, the cavity extends along the thread structure of the stent body 210, that is, it is located inside the thread structure. In addition, In order to facilitate recovery 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 a natural state.

In some embodiments, the structure of the stent main body 210 of the radiotherapy stent 200 is changed. Referring to FIG. 21 , the stent main body 210 includes a drug-loaded section 2101 and a support section 2102 , and the support section 2102 is distributed in a spiral shape and against the inner wall of the tissue tract 100 , the drug-loaded section 2101 is connected to the support section 2102 and is located at the axis position of the stent body 210, therefore, the drug-loaded section 2101 will not be close to or contact any surface of the tissue pipeline 100, thus avoiding the tissue damage of the drug-loaded section 2101 to its contact position. Too close to cause too much radiation. Secondly, since many radioactive substances are in a liquid state when loaded into the drug-loaded section 2101, if the drug-loaded section 2101 resists the inner wall of the tissue pipeline 100 in a spiral shape, the radioactive substances will be different according to the position of implantation, or the state of the human body (position position) causes the drug-loaded section 2101 to flow to a certain side of the stent body 210, thereby affecting the therapeutic effect.

Furthermore, the drug-loaded section 2101 is located on one side of the axis of the stent main body 210. When a lesion appears on one side of the tissue tract 100, the drug-loaded section 2101 on one side can be closer to the lesion position relative to the axial position, thereby obtaining a more good therapeutic effect.

In some embodiments, referring to FIG. 22, the stent body includes a plurality of drug-loaded segments 2101 and a plurality of support segments 2102. Preferably, at least one drug-loaded segment 2101 is located between the two support segments 2102 to achieve the most stable Implantation effect. As a further optimization of this embodiment, all drug-loading sections 2101 have supporting sections 2102 at their distal and proximal ends, so that the area loaded with radioactive substances is stably maintained at the axial position, and remains stable when the tissue channel 100 deforms or moves. The stability of the drug-loaded section 2101 can be maintained.

In some embodiments, referring to FIG. 23, the supporting section 2102 of the stent body 210 further includes a helical section 2103 and a transition section 2104, the transition section 2104 extends in the axial direction, and the transition section 2104 connects two adjacent helical sections 2103, preferably , the two adjacent transition sections 2104 are located at different positions in the circumferential direction (that is, the two adjacent transition sections 2104 are parallel), so as to provide the entire stent main body 210 with axial support at multiple circumferential positions, from the circumferential direction The multiple positions prevent shortening of the stent body 210 .

Further, the surface of part of the bracket body 210 in contact with the human body is coated with a material that increases friction (such as silica gel or other polymer materials), or the part is subjected to rough treatment (such as frosting treatment, etc.); preferably, this part The region is the transition segment 2104.

Further, in some embodiments, referring to FIG. 24 , the transition section 2014 of the stent body 210 is further provided with a wave section 2105 extending along the axial direction, and the wave section 2105 is partially embedded into the pipeline tissue 100, which can increase the anchor of the stent body 210. That is to say, the transition section 2014 includes an anchoring enhancement structure. At the same time, the anchoring capacity of the main body 210 of the stent can be increased while avoiding scraping the inner wall of the tissue channel when the stent is taken out by means of the previous removal method. rubbed and damaged.

In some embodiments, the stent body 210 includes a solid section 211 and a drug-loaded section 212 with a built-in cavity. The drug-loaded section 212 can be set in multiples, and each drug-loaded section 212 includes a drug insertion port for inserting drugs. After the medicine is put in, put the medicine into the mouth and seal it. The solid section 211 serves to strengthen the radial support capability of the bracket 210 and increase the anti-displacement performance.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims

A radiotherapy stent, characterized in that it comprises:

A stent main body, the stent main body can elastically resist the tube wall of the tissue duct, and the stent main body includes an inner cavity for accommodating radioactive substances;

A sealing plug head is detachably arranged at the outlet of the inner cavity to close or open the outlet.
The radiotherapy stent according to claim 1, wherein the radiotherapy stent also includes an inner tube covering the inner wall of the lumen, a part of the inner tube protrudes from the stent main body, and is connected to the stent main body. The end of the stent is turned over to form a turned portion, and the turned portion covers at least a part of the outer side of the stent main body.
The radiotherapy stent according to claim 2, wherein the sealing plug head includes the baffle facing the stent main body, and the baffle surrounds the opening facing the stent main body to seal the inner cavity. Achieving a seal.
The radiotherapy stent according to claim 3, wherein the end of the baffle protrudes inwardly from an auxiliary baffle, and the auxiliary baffle is against the covering film or the stent main body or the turning portion .
The radiotherapy stent according to claim 3, wherein the middle part of the sealing plug protrudes toward the stent main body to form a bulge, and the bulge snaps into the inside of the inner tube, and the overturned The part is located on the outside of the protruding part.
The radiotherapy support according to claim 3, wherein the distance between the baffle plate and the main body of the support is smaller than or equal to the thickness of the turning portion.
The radiotherapy support according to claim 4, wherein the auxiliary baffle is located between the end of the main body of the support and the groove closest to the end.
The radiotherapy stent according to any one of claims 2-7, wherein the middle section surface of the inner tube includes a plurality of protrusions, and the protrusions are arranged corresponding to the grooves of the stent main body.
The radiotherapy bracket according to claim 8, wherein the turning part includes the protrusion to be snapped into the groove.
The radiotherapy stent according to claim 1, wherein the stent main body includes a connected drug-loaded section and a supporting section, and the stent main body also includes an unstressed natural state and a stressed compressed state, and the loaded The drug segment includes a lumen for containing radioactive substances, at least the proximal end of the stent main body extends along the axis in a natural state, the support segment includes a helical structure, and the drug-loaded segment is connected to the support segment and located at The position of the axis of the stent body may be located on one side of the axis of the stent body.
The radiotherapy stent according to claim 10, wherein the stent main body comprises a plurality of the drug-loaded segments and a plurality of the support segments, at least one of the drug-loaded segments is located between two adjacent between support segments.
The radiotherapy stent according to claim 11, characterized in that, the distal end and the proximal end of each of the drug-loaded segments have the support segments.
The radiotherapy stent according to claim 10, wherein the supporting section comprises a helical section and a transition section, the transition section extends axially, and the transition section connects two adjacent helical sections.
The radiotherapy stent according to claim 13, wherein two adjacent transition sections are distributed along the circumferential direction and are parallel to each other.
The radiotherapy stent according to claim 13, wherein the transition section comprises an anchoring enhancement structure.