Biliary and duodenal metal stent

Abstract

The application provides a biliary duodenal tube cavity metal stent, and relates to the technical field of duodenal stents, which comprises a stent body, an anti-reflux component, a release air bag and a plurality of connecting pieces. The stent body is formed into a net-shaped cylindrical structure, and a through guide channel is formed in the stent body. The anti-reflux component is installed in the guide channel and comprises a first diaphragm and a second diaphragm, the first diaphragm and the second diaphragm are connected with the stent body respectively, and the first diaphragm is arranged above the second diaphragm. The release air bag is used for extending into the guide channel and for expanding the stent body, the release air bag comprises a first bag body and a second bag body, the first bag body is connected with the first diaphragm through a connecting piece, the second bag body is connected with the second diaphragm through a connecting piece, and the connecting piece is configured to be able to be broken under a certain tension. The application has a simple and direct structure, can effectively reduce fluid turbulence caused by a complex spiral structure, and can more effectively prevent the reflux of duodenal contents and relieve the discomfort of patients.

Description

Technical Field

[0001] This invention relates to the field of duodenal stent technology, and more specifically to a metal stent for the biliary duodenal lumen. Background Technology

[0002] Duodenal stents are commonly used to relieve malignant intestinal obstruction caused by pancreatic cancer, duodenal tumors, or other lesions. While stent placement physically opens the blocked intestine, it inevitably disrupts the normal anatomical structure and physiological function of the gastrointestinal tract, thus triggering reflux problems.

[0003] In existing related technologies, such as the patent document with publication number CN112220594B (a conical spiral valve anti-reflux biliary stent), the reflux problem is solved by setting a conical spiral valve structure. However, after long-term use, duodenal contents or intestinal fluid (mainly biofilms formed by bacteria and mucin, proteins, fatty acid calcium salt crystals, dietary fiber, etc.) easily become entangled on the spiral valve, leading to valve blockage. This results in most patients needing stent replacement within a few months, increasing the burden on patients. Summary of the Invention

[0004] In order to solve the technical problems in related technologies, the present invention provides a metal stent for the biliary and duodenal lumen.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] Metal stents for the biliary and duodenal duct lumen, including:

[0007] The main body of the support is formed into a mesh-like cylindrical structure, and a through guide channel is formed inside it;

[0008] The anti-backflow component installed in the guide channel includes a first diaphragm and a second diaphragm, the first diaphragm and the second diaphragm are respectively connected to the support body, and the first diaphragm is disposed above the second diaphragm;

[0009] The system includes a release airbag and several connectors. The release airbag is used to extend into the guide channel and to expand the support body. The release airbag includes a first airbag body and a second airbag body. The first airbag body is connected to the first diaphragm through the connectors. The second airbag body is connected to the second diaphragm through the connectors. The connectors are configured to break under a certain tensile force.

[0010] The biliary duodenal stent includes an inserted state and a disengaged state. In the inserted state, the release balloon is contracted within the stent body, and the anti-backflow assembly is connected to the release balloon via several connectors. In the disengaged state, the release balloon inflates to open the stent body, and when the release balloon disengages from the stent body, the first balloon and the second balloon contract sequentially and withdraw one by one, causing the corresponding connectors to break, so that the first diaphragm can rest on the second diaphragm.

[0011] Optionally, in the axial direction of the guide channel, the projection of the first diaphragm and the projection of the second diaphragm together cover the projection of the guide channel, and the projection of the first diaphragm partially falls within the projection of the second diaphragm.

[0012] Optionally, the width L of the overlapping portion of the projections of the first diaphragm and the second diaphragm satisfies: D×10%≥L≥D×5%, where D is the diameter of the guide channel.

[0013] Optionally, the biliary duodenal lumen metal stent further includes a first mounting block and a second mounting block, the first mounting block and the second mounting block being disposed within the guide channel and disposed opposite to each other on the inner wall of the stent body, the first diaphragm being mounted on the first mounting block and the second diaphragm being mounted on the second mounting block.

[0014] Optionally, the anti-backflow assembly further includes at least two stabilizing blocks, which are disposed within the guide channel and opposite to each other on the inner wall of the support body. The second mounting block is located between the two stabilizing blocks, and the two stabilizing blocks are used to support the portion of the second diaphragm away from the second mounting block.

[0015] Optionally, two stabilizing blocks are provided, and the line connecting the two stabilizing blocks is perpendicular to the line connecting the first mounting block and the second mounting block.

[0016] Optionally, both the first and second bladders are formed in a semi-cylindrical shape, and the first and second bladders together form a cylindrical release bladder.

[0017] Optionally, a plurality of connectors connected to the first capsule are arranged in a fan-shaped divergent pattern, with the diffusion ends of the plurality of connectors connected to the first membrane and the convergence ends of the plurality of connectors connected to the first capsule.

[0018] A plurality of connectors connected to the second capsule are arranged in a fan-shaped divergent pattern. The diffusion ends of the plurality of connectors are connected to the second membrane, and the contraction ends of the plurality of connectors are connected to the second capsule.

[0019] Optionally, the connector is configured as a connecting rope, the connecting rope comprising a rope body segment and a weakening segment connected to each other, the end of the weakening segment away from the rope body segment being connected to the anti-backflow component, and the end of the rope body segment away from the weakening segment being connected to the release airbag;

[0020] The radial dimension of the weakened section is smaller than the radial dimension of the rope section.

[0021] Optionally, the length of the weakened segment is less than or equal to 2 mm.

[0022] Beneficial effects:

[0023] 1. Through the above technical solution, firstly, the anti-backflow component of the present invention includes a first membrane and a second membrane, both of which are respectively connected to the support body, with the first membrane positioned above the second membrane. In the disengaged state, the first membrane can rest against the second membrane, thus allowing intestinal contents to push the membrane open and pass through during normal downward flow. However, when contents attempt to reflux, the membrane will close under reflux pressure, blocking the backflow. Compared with the spiral valves in existing related technologies, the structure of the present invention is simpler and more direct, effectively reducing fluid disturbances that may be caused by complex spiral structures, thereby more effectively preventing the reflux of duodenal contents (such as bile and intestinal fluid) and alleviating patient discomfort.

[0024] Second, the release airbag of this invention includes a first airbag and a second airbag, which are connected to an anti-backflow component via connectors. In the inserted state, the release airbag retracts within the support body, and the anti-backflow component is connected to the airbag via the connectors, ensuring the component maintains a stable position during delivery. In the disengaged state, the release airbag inflates to expand the support body, fixing the support in the corresponding position. Then, the second and first airbags retract sequentially and withdraw one at a time. This sequential withdrawal mechanism causes the corresponding connectors to break sequentially, allowing the first and second diaphragms to be released separately and overlap. This deployment method ensures that the anti-backflow component automatically and accurately activates after the support expands, requiring no additional operation. Furthermore, the connector's design for breaking under tension provides a controllable release process, effectively preventing diaphragm displacement or entanglement during deployment, improving the success rate and reliability of the surgery.

[0025] Third, the anti-backflow assembly of the present invention comprises only a first diaphragm and a second diaphragm, rather than the spiral valves of existing related technologies. The diaphragms have a flat or near-flat structure (e.g., curved surface), which effectively reduces the chance of duodenal contents (such as biofilms, protein crystals, etc.) entangled and accumulating on the valve. In contrast, the complex structure of spiral valves is more likely to retain contents, leading to blockage. Therefore, the anti-backflow assembly of the present invention can effectively extend the lifespan of the stent, reduce the frequency of replacement, and thus reduce the burden on patients.

[0026] Fourth, during the installation of the biliary and duodenal lumen metal stent of this invention, the balloon is deployed in stages; that is, the second balloon and the first balloon contract sequentially and withdraw one at a time, allowing the connectors to break in stages. This avoids the possibility of sudden detachment or positional deviation of the diaphragm that might result from simultaneous breakage of all connectors, ensuring that the first diaphragm rests stably on the second diaphragm. This effectively improves deployment accuracy, reduces the need for intraoperative adjustments, and lowers operational risks.

[0027] 2. Other beneficial effects or advantages of the present invention will be described in detail in conjunction with specific structures in specific embodiments. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, it should be understood that the proportional relationship of each component in the drawings of this specification does not represent the proportional relationship in the actual material selection and design, but is only a schematic diagram of the structure or position, wherein:

[0029] Figure 1 This is a three-dimensional structural diagram of a metal stent for the biliary duodenal lumen provided in an exemplary embodiment of the present invention, wherein the metal stent for the biliary duodenal lumen is in an extended state.

[0030] Figure 2 This is a three-dimensional structural diagram of a metal stent for the biliary duodenal lumen provided in an exemplary embodiment of the present invention, wherein the metal stent for the biliary duodenal lumen is in a detached state.

[0031] Figure 3 This is a schematic diagram of the assembly state of the anti-backflow component, the first mounting block, and the second mounting block provided in an exemplary embodiment of the present invention;

[0032] Figure 4This is a three-dimensional structural diagram of a support body provided in an exemplary embodiment of the present invention, wherein a stabilizing block, a first mounting block, and a second mounting block are also shown;

[0033] Figure 5 This is a three-dimensional structural diagram of a connector provided in an exemplary embodiment of the present invention.

[0034] Explanation of the labels in the attached drawings:

[0035] 100-Metal stent for biliary and duodenal lumen; 1-Stent body; 11-Guide channel; 2-Anti-backflow component; 21-First diaphragm; 22-Second diaphragm; 23-Stabilizing block; 3-Release balloon; 31-First balloon body; 32-Second balloon body; 4-Connector; 41-Rope section; 42-Weakening section; 51-First mounting block; 52-Second mounting block. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0038] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] like Figures 1 to 5 As shown, this embodiment provides a biliary duodenal lumen metal stent 100, including a stent body 1, an anti-backflow component 2, a release balloon 3, and several connectors 4. The stent body 1 is formed as a mesh-like cylindrical structure with a through-flow guide channel 11. The anti-backflow component 2 is installed within the guide channel 11 and includes a first diaphragm 21 and a second diaphragm 22. The first diaphragm 21 and the second diaphragm 22 are respectively connected to the stent body 1, with the first diaphragm 21 positioned above the second diaphragm 22. The release balloon 3 extends into the guide channel 11 and expands the stent body 1. The release balloon 3 includes a first balloon body 31 and a second balloon body 32. The first balloon body 31 is connected to the first diaphragm 21 via connectors 4, and the second balloon body 32 is connected to the second diaphragm 22 via connectors 4. The connectors 4 are configured to break under a certain tensile force.

[0040] The biliary duodenal lumen metal stent 100 includes an inserted state and a disengaged state. In the inserted state, the release balloon 3 is contracted within the stent body 1, and the anti-backflow component 2 is connected to the release balloon 3 through several connectors 4. In the disengaged state, the release balloon 3 is inflated to open the stent body 1. When the release balloon 3 is disengaged from the stent body 1, the first balloon 31 and the second balloon 32 contract sequentially and withdraw one by one, causing the corresponding connectors 4 to break, so that the first diaphragm 21 can rest on the second diaphragm 22.

[0041] To facilitate understanding by those skilled in the art, the working principle / process of this invention will be explained below.

[0042] When stent installation is required, the entire biliary-duodenal lumen metal stent 100 is inserted into the pre-selected position according to the existing stent installation method. Then, the first bladder 31 and the second bladder 32 are simultaneously inflated and expanded to open the stent body 1. Then, the gas in the second bladder 32 is released to cause it to contract. During this process, the connector 4 connecting the second diaphragm 22 and the second bladder 32 breaks, allowing the second diaphragm 22 to be released. Subsequently, the gas in the first bladder 31 is released to cause it to contract. At this time, the connector 4 connecting the first diaphragm 21 and the first bladder 31 breaks, allowing the first diaphragm 21 to be released. In this way, the first diaphragm 21 rests on the second diaphragm 22, completing the installation of the entire biliary-duodenal lumen metal stent 100.

[0043] Through the above technical solution, firstly, the anti-backflow component 2 of the present invention includes a first membrane 21 and a second membrane 22, both of which are connected to the support body 1, with the first membrane 21 positioned above the second membrane 22. In the disengaged state, the first membrane 21 rests against the second membrane 22, allowing intestinal contents to pass through by pushing the membrane open during normal downward flow. However, when contents attempt to reflux, the membrane closes under reflux pressure, blocking the backflow. Compared to the spiral valves in existing related technologies, the structure of the present invention is simpler and more direct, effectively reducing fluid disturbances that may result from complex spiral structures, thereby more effectively preventing the reflux of duodenal contents (such as bile and intestinal fluid) and alleviating patient discomfort.

[0044] Second, the release airbag 3 of the present invention includes a first airbag 31 and a second airbag 32, and is connected to the anti-backflow component 2 via a connector 4. In the inserted state, the release airbag 3 retracts within the support body 1, and the anti-backflow component 2 is connected to the airbag via the connector 4, ensuring the component maintains a stable position during delivery. In the disengaged state, the release airbag 3 inflates to expand the support body 1, fixing the support in the corresponding position. Then, the second airbag 32 and the first airbag 31 retract sequentially and withdraw one by one. This sequential withdrawal mechanism causes the corresponding connector 4 to break sequentially, allowing the first diaphragm 21 and the second diaphragm 22 to be released sequentially and form an overlapping relationship. This deployment method ensures that the anti-backflow component 2 is automatically and accurately activated after the support expands, without additional operation. Furthermore, the design of the connector 4 to break under tension provides a controllable release process, effectively preventing displacement or entanglement of the diaphragms during deployment, improving the success rate and reliability of the surgery.

[0045] Third, the anti-backflow component 2 of the present invention comprises only a first diaphragm 21 and a second diaphragm 22, rather than the spiral valves of existing related technologies. The diaphragms have a flat or near-flat structure (e.g., curved surface), which effectively reduces the chance of duodenal contents (such as biofilms, protein crystals, etc.) entangled and accumulating on the valve. In contrast, the complex structure of spiral valves is more likely to retain contents, leading to blockage. Therefore, the anti-backflow component 2 of the present invention can effectively extend the service life of the stent, reduce the frequency of replacement, and thus reduce the burden on patients.

[0046] Fourth, during the installation of the biliary-duodenal lumen metal stent 100 of the present invention, the release balloon 3 is withdrawn in stages, that is, the second balloon 32 and the first balloon 31 contract sequentially and withdraw one by one, allowing the connector 4 to break in stages. This avoids the possibility of sudden detachment or positional deviation of the diaphragm that might result from the simultaneous breakage of all connectors 4, ensuring that the first diaphragm 21 can stably rest on the second diaphragm 22. This effectively improves the precision of deployment, reduces the need for adjustments during surgery, and lowers operational risks.

[0047] In one embodiment of the present invention, such as Figure 3 As shown, in the axial direction of the guide channel 11, the projection of the first diaphragm 21 and the projection of the second diaphragm 22 together cover the projection of the guide channel 11, and the projection portion of the first diaphragm 21 falls within the projection of the second diaphragm 22.

[0048] In this way, the first diaphragm 21 and the second diaphragm 22, when overlapped, can completely cover the cross-section of the stent channel without any direct gaps or openings. Simultaneously, a portion of the first diaphragm 21 overlaps with the second diaphragm 22, rather than a simple edge-to-edge connection. This improves the reliability of anti-reflux, eliminates the risk of failure due to a single diaphragm's inadequate sealing or slight displacement, and ensures the anti-reflux effect. Furthermore, the arrangement of the first diaphragm 21 and the second diaphragm 22 makes it difficult for duodenal contents (such as biofilms, fibers, etc.) to find complex geometric spaces to entangle and adhere to, preventing contents from accumulating on the valve structure.

[0049] In one embodiment of the present invention, the width L of the overlapping portion of the projection of the first diaphragm 21 and the second diaphragm 22 can be set as: D×10%≥L≥D×5%, where D is the diameter of the guide channel 11.

[0050] Thus, by configuring the first diaphragm 21 and the second diaphragm 22 in this way, a balance between sealing and unobstructed flow can be achieved. Specifically, if the overlap is too small (e.g., less than 5%), manufacturing tolerances, minor deformations during long-term use, or positional misalignments may lead to a poor seal and backflow gaps. This lower limit ensures that even under the most unfavorable conditions, there is still sufficient overlap area to maintain reliable closure and prevent backflow. If the overlap is too large (e.g., greater than 10%), a greater fluid pressure is required to force open the two tightly overlapping diaphragms when the fluid flows downward normally. This may cause some flow resistance and may even lead to poor drainage. This upper limit effectively prevents excessive overlap area from affecting the unobstructed flow of the lumen.

[0051] In one embodiment of the present invention, such as Figures 2 to 4 As shown, the biliary duodenal lumen metal stent 100 of the present invention may further include a first mounting block 51 and a second mounting block 52. The first mounting block 51 and the second mounting block 52 are disposed in the guide channel 11 and are disposed opposite to each other on the inner wall of the stent body 1. The first diaphragm 21 is mounted on the first mounting block 51 and the second diaphragm 22 is mounted on the second mounting block 52.

[0052] In this embodiment, firstly, the arrangement of the first mounting block 51 and the second mounting block 52 provides a reliable and robust connection foundation. Specifically, the mesh structure of the mesh metal support itself is not an ideal welding or sewing plane. The first mounting block 51 and the second mounting block 52 can provide a locally reinforced, flat, and stable platform for the first diaphragm 21 and the second diaphragm 22, allowing the first diaphragm 21 and the second diaphragm 22 to be reliably fixed thereon through various methods such as fastening, bonding, sewing, or mechanical clamping. This design greatly enhances the connection stability of the anti-backflow component 2 under long-term exposure to chyme erosion, fluid pressure fluctuations, and intestinal peristalsis, effectively preventing the risk of the diaphragm detaching from the support.

[0053] Secondly, the first mounting block 51 and the second mounting block 52 serve as intermediate carriers, which can distribute the load transmitted from the first diaphragm 21 and the second diaphragm 22 to a larger contact area with the inner wall of the support body 1. This can avoid excessive stress concentration, thereby reducing the risk of the support mesh wire breaking due to fatigue, and also prevent the support from deforming due to excessive local stress, which helps to maintain the overall structural integrity and long-term durability of the support.

[0054] In one embodiment of the present invention, such as Figures 1 to 4 As shown, the anti-backflow component 2 of the present invention may further include at least two stabilizing blocks 23. The two stabilizing blocks 23 are disposed in the guide channel 11 and disposed opposite to each other on the inner wall of the support body 1. The second mounting block 52 is located between the two stabilizing blocks 23. The two stabilizing blocks 23 are used to support the portion of the second diaphragm 22 away from the second mounting block 52.

[0055] In this way, the stabilizing blocks 23 effectively prevent the collapse of the middle of the second diaphragm 22, ensuring sealing reliability. Specifically, at least two stabilizing blocks 23 provide key auxiliary support points below the free end of the second diaphragm 22, thereby supporting the diaphragm and keeping its middle flat or maintaining a preset curvature. This ensures that in the closed state, the first diaphragm 21 that rests on top can form a tight and continuous contact with a complete and flat second diaphragm 22, thereby eliminating backflow gaps caused by the collapse of the middle of the second diaphragm 22, and significantly improving the long-term reliability and consistency of the anti-backflow seal.

[0056] Secondly, it can optimize the stress state of the diaphragm and improve the structural durability. The introduction of at least two stabilizing blocks 23 can effectively share the fluid pressure and gravity borne by the second diaphragm 22, reduce the stress concentration at the connection of the second mounting block 52 and the diaphragm itself, thereby optimizing the stress state of the diaphragm and improving the structural durability.

[0057] Third, by using the stabilizing block 23 to maintain the free end of the second diaphragm 22 at a predetermined height, it helps to maintain a smoother and more regular fluid channel and prevents the second diaphragm 22 from deflecting too downwards, which could lead to seal failure.

[0058] In one embodiment of the present invention, such as Figure 3 As shown, the stabilizing block 23 of the present invention can be configured as two, and the line connecting the two stabilizing blocks 23 is perpendicular to the line connecting the first mounting block 51 and the second mounting block 52.

[0059] In this way, the cross-shaped support layout (the two stabilizing blocks 23 are arranged in a cross shape with the first mounting block 51 and the second mounting block 52) can provide a stable and balanced support foundation for the second diaphragm 22, effectively preventing the second diaphragm 22 from warping, twisting or drooping on one side in any direction, and ensuring that the second diaphragm 22 as a whole maintains the expected flat or slightly curved state.

[0060] Meanwhile, the two stabilizers 23, arranged in this way, are distributed on both sides of the middle of the free end of the second diaphragm 22. They can effectively support the main part of the diaphragm with the simplest structure. Compared with other potentially more complex arrangements (such as asymmetric, oblique, etc.), this regular and symmetrical layout leaves a regular and predictable flow channel for the fluid to pass through, avoiding unnecessary turbulence or dead corners. While providing stable support, it minimizes the obstruction to the smooth flow of the pipe. In addition, it can also reduce the blockage problem caused by the contents getting tangled in the stabilizers 23 to a certain extent.

[0061] In one embodiment of the present invention, such as Figure 1 As shown, the first capsule 31 and the second capsule 32 of the present invention can both be formed as semi-cylindrical, and the first capsule 31 and the second capsule 32 together form a cylindrical release airbag 3.

[0062] In this way, the first bladder 31 and the second bladder 32 can not only be smoothly and gradually withdrawn, but also provide a uniform and sufficient radial expansion force, so that the support body 1 can be opened smoothly and completely so that it can be anchored in the preset position.

[0063] In one embodiment of the present invention, such as Figure 1 As shown, a plurality of connectors 4 connected to the first capsule 31 are arranged in a fan-shaped divergent pattern. The diffusion ends of the plurality of connectors 4 are connected to the first membrane 21, and the convergence ends of the plurality of connectors 4 are connected to the first capsule 31. A plurality of connectors 4 connected to the second capsule 32 are arranged in a fan-shaped divergent pattern. The diffusion ends of the plurality of connectors 4 are connected to the second membrane 22, and the convergence ends of the plurality of connectors 4 are connected to the second capsule 32.

[0064] In this way, firstly, the fan-shaped arrangement means that the connection points (diffusion ends) of the connectors 4 on the first diaphragm 21 and the second diaphragm 22 are distributed over a wider area, while the connection points (contraction ends) on the first bladder 31 and the second bladder 32 are relatively concentrated. This "divergent-contracting" structure allows the tension exerted on the first diaphragm 21 and the second bladder 22 during contraction and withdrawal to be evenly distributed over a wider attachment area on the diaphragm through multiple connectors 4. This effectively prevents the diaphragm from twisting, tilting, or experiencing single-point stress concentration due to uneven force during release. It also ensures that the first diaphragm 21 and the second diaphragm 22 can smoothly and accurately reach the preset overlap position after the connectors 4 break, thus guaranteeing the reliable implementation of the anti-backflow function.

[0065] Second, the other ends (converging ends) of multiple connectors 4 connected to the same capsule are converged onto the capsule, forming a clear force transmission path. When the first capsule 31 or the second capsule 32 contracts and prepares to withdraw, the applied tension acts simultaneously and evenly on all connectors 4 connected to it. In this way, it can be ensured that all connectors 4 in the same group can reach their fracture threshold and break almost synchronously, thereby allowing the corresponding parts of the first diaphragm 21 or the second diaphragm 22 to be released completely at once. To avoid the chaotic state of diaphragm parts being suspended and parts being loose due to the breakage of individual connectors 4, it is the key to ensuring that the sequential release process of "withdrawing one by one, with connectors 4 breaking one by one" can be executed in an orderly and reliable manner.

[0066] In one embodiment of the present invention, such as Figure 5 As shown, the connector 4 of the present invention can be configured as a connecting rope, which includes a rope body section 41 and a weakening section 42 connected to each other. The end of the weakening section 42 away from the rope body section 41 is connected to the anti-backflow component 2, and the end of the rope body section 41 away from the weakening section 42 is connected to the release airbag 3. The radial dimension of the weakening section 42 is smaller than the radial dimension of the rope body section 41.

[0067] Thus, firstly, by designing the connecting rope as rope segments 41 and weakened segments 42 with different radial dimensions, and explicitly specifying that the weakened segment 42 is smaller, a pre-designed mechanical weak point is artificially created at this location. This structure ensures that when the release airbag 3 contracts and applies tension, breakage will inevitably occur only at the weakened segment 42. This completely avoids the uncertainty of breakage points randomly occurring at rope segments 41, knots, or connection points with components. Achieving a high degree of consistency in breaking force and predictability of breakage behavior provides a reliable guarantee for the entire sequential release process.

[0068] Second, the rope section 41 maintains a large radial dimension to ensure sufficient tensile strength, thereby reliably securing the anti-backflow component 2 during the transport and expansion of the support, preventing premature breakage due to accidental pulling. This achieves the ideal performance of being sufficiently robust during transport and accurately disconnecting upon release (the rope section 41 ensures the reliability of the initial fixation, while the weakening section 42 is responsible for achieving precise disengagement under a predetermined tension).

[0069] Third, if the connecting rope breaks at an uncertain location, it may leave a long, irregular residual section, which could cause unnecessary entanglement or irritation inside the body. Controlling the breakage to a short, weakened segment 42 results in a shorter, more regular residual end. This allows the doctor to receive clear and consistent force feedback when disengaging the airbag 3. When the tension suddenly disappears, it is immediately apparent that a set of connecting parts 4 has successfully disconnected, providing a clear signal for the next step. This makes the entire release process smoother and more intuitive, reducing operational difficulty and uncertainty.

[0070] In one embodiment of the invention, the length of the weakened segment 42 can be set to be less than or equal to 2 mm. This not only effectively ensures rapid and decisive breakage, avoiding unpredictable tensile behavior (when the airbag 3 contracts and applies tension, stress rapidly concentrates on the extremely short weakened segment 42 and reaches its breaking limit. This causes the connector 4 to break quickly and cleanly, like a pre-notched tear), but also effectively achieves consistency and predictability of the breaking force (this ≤2 mm length limit ensures that the weakened segments 42 of all connecting ropes exhibit high consistency in mechanical properties. This means that each connecting rope will break under almost identical tension. This predictability ensures that all connectors 4 connected to the same airbag break almost synchronously, thus smoothly releasing the diaphragm, rather than some breaking first and others later, causing diaphragm skewing or jamming).

[0071] Furthermore, because the weakened segment 42 itself is extremely short (≤2mm), the residual end produced after breakage is also very short. This not only reduces the feeling of a foreign body and irritation in the body (the extremely short residual end is softer and less likely to cause physical irritation or friction to the intestinal wall), but also reduces long-term risks (the shorter residual end is less likely to become an anchor point for contents to become entangled in the complex intestinal environment, thereby reducing the long-term risk of local blockage or inflammation).

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A metal stent for the biliary and duodenal lumen, characterized in that, include: The main body of the support (1) is formed as a mesh cylindrical structure, and a through guide channel (11) is formed inside it. The anti-backflow assembly (2) installed in the guide channel (11) includes a first diaphragm (21) and a second diaphragm (22). The first diaphragm (21) and the second diaphragm (22) are respectively connected to the support body (1). The first diaphragm (21) is disposed above the second diaphragm (22). Release airbag (3) and several connectors (4), the release airbag (3) is used to extend into the guide channel (11) and to open the support body (1), the release airbag (3) includes a first bladder (31) and a second bladder (32), the first bladder (31) is connected to the first diaphragm (21) through the connectors (4), the second bladder (32) is connected to the second diaphragm (22) through the connectors (4), and the connectors (4) are configured to break under a certain tensile force; The biliary duodenal lumen metal stent includes an inserted state and a disengaged state. In the inserted state, the release balloon (3) is contracted within the stent body (1), and the anti-backflow component (2) is connected to the release balloon (3) through several connectors (4). In the disengaged state, the release balloon (3) is inflated to open the stent body (1), and when the release balloon (3) disengages from the stent body (1), the first balloon (31) and the second balloon (32) contract sequentially and withdraw one by one, causing the corresponding connectors (4) to break, so that the first diaphragm (21) can rest on the second diaphragm (22). In the axial direction of the guide channel (11), the projection of the first diaphragm (21) and the projection of the second diaphragm (22) together cover the projection of the guide channel (11), and the projection portion of the first diaphragm (21) falls within the projection of the second diaphragm (22).

2. The biliary duodenal lumen metal stent according to claim 1, characterized in that, The width L of the overlapping portion of the projection of the first diaphragm (21) and the second diaphragm (22) satisfies: D×10%≥L≥D×5%, where D is the diameter of the guide channel (11).

3. The biliary duodenal lumen metal stent according to claim 1, characterized in that, The biliary duodenal lumen metal stent also includes a first mounting block (51) and a second mounting block (52). The first mounting block (51) and the second mounting block (52) are disposed in the guide channel (11) and are disposed opposite to each other on the inner wall of the stent body (1). The first diaphragm (21) is mounted on the first mounting block (51) and the second diaphragm (22) is mounted on the second mounting block (52).

4. The biliary-duodenal lumen metal stent according to claim 3, characterized in that, The anti-backflow component (2) further includes at least two stabilizing blocks (23), which are disposed in the guide channel (11) and disposed opposite to each other on the inner wall of the support body (1). The second mounting block (52) is located between the two stabilizing blocks (23), and the two stabilizing blocks (23) are used to support the portion of the second diaphragm (22) away from the second mounting block (52).

5. The biliary-duodenal lumen metal stent according to claim 4, characterized in that, The stabilizing block (23) is configured as two, and the line connecting the two stabilizing blocks (23) is perpendicular to the line connecting the first mounting block (51) and the second mounting block (52).

6. The biliary-duodenal lumen metal stent according to claim 1, characterized in that, The first bladder (31) and the second bladder (32) are both formed in a semi-cylindrical shape, and the first bladder (31) and the second bladder (32) together form a cylindrical release bladder (3).

7. The biliary duodenal lumen metal stent according to claim 1, characterized in that, A plurality of connectors (4) connected to the first capsule (31) are arranged in a fan-shaped divergent pattern. The diffuser ends of the plurality of connectors (4) are connected to the first membrane (21), and the converging ends of the plurality of connectors (4) are connected to the first capsule (31). A number of connectors (4) connected to the second capsule (32) are arranged in a fan-shaped divergent pattern. The diffusion ends of the connectors (4) are connected to the second membrane (22), and the contraction ends of the connectors (4) are connected to the second capsule (32).

8. The biliary-duodenal lumen metal stent according to claim 1, characterized in that, The connector (4) is configured as a connecting rope, which includes a rope body segment (41) and a weakening segment (42) connected to each other. The end of the weakening segment (42) away from the rope body segment (41) is connected to the anti-backflow component (2), and the end of the rope body segment (41) away from the weakening segment (42) is connected to the release airbag (3). The radial dimension of the weakening section (42) is smaller than the radial dimension of the rope section (41).

9. The biliary duodenal lumen metal stent according to claim 8, characterized in that, The length of the weakened segment (42) is less than or equal to 2 mm.

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