A biliary stent and its preparation method

Abstract

This invention relates to the field of medical device technology, and provides a biliary stent and its preparation method, comprising: a stent body, the stent body including a first structure and a second structure sequentially from one end to the other, the second structure including a channel body that maintains a spatial spiral in its natural state; the first structure including a first support ring and multiple first support wires; and a fixing structure, one end of the fixing structure being connected to the first support ring and / or multiple first support wires, and the other end being connected to the stent body, such that the multiple first support wires protrude outwards from the stent body, and the maximum diameter of the first structure is greater than the minimum diameter of the channel body; when the fixing structure loses its fixing function, the multiple first support wires are straight, and the average diameter of the first structure is smaller than the average diameter of the channel body. The biliary stent of this application solves the technical problems of stents in the prior art, such as easy displacement, easy breakage leading to large stent fragments, and difficulty in subsequent removal.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a biliary stent and its preparation method. Background Technology

[0002] Existing biliary stents made of non-biodegradable materials require a second surgery for removal after fulfilling their function, increasing patient suffering. Biodegradable biliary stents are a better option to avoid this second surgery. However, current biodegradable stents have several issues that need to be addressed. One is their tendency to migrate. Furthermore, during degradation, biodegradable biliary stents may fragment into large, irregular pieces within the bile duct, such as breaking irregularly in the middle to form two large fragments. These fragments could potentially damage the bile duct or even the pancreas. Additionally, due to the degradation period of biodegradable materials, larger stent fragments are difficult to remove after the stent has fulfilled its function, potentially leading to complications, which is not beneficial for patients.

[0003] Therefore, there is a need for a biliary stent that is not prone to displacement in the early stages after implantation, reduces the generation of large fragments in the bile duct during the later stages of stent support, and can be expelled as soon as support is completed. Summary of the Invention

[0004] The purpose of this invention is to provide a biliary stent and its preparation method, so as to solve the technical problems of stent easy displacement, easy breakage forming large stent fragments, and difficulty in subsequent removal in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a biliary stent, comprising: a stent body, the stent body comprising a first structure and a second structure sequentially from one end to the other, the second structure comprising a channel body that maintains a spatial spiral in its natural state, the channel body comprising a guide cavity for a guide wire to pass through and fluid to flow through, the stent body comprising a biodegradable material; the first structure comprising a first support ring and a plurality of first support wires, one end of the plurality of first support wires being connected to the first support ring, and the other end of the plurality of first support wires being connected to the second structure, the diameter of the first support ring being greater than or equal to half the diameter of the end of the channel body near the first structure and less than the diameter of the end of the channel body near the first structure; a fixing structure, one end of the fixing structure being connected to the first support ring and / or the plurality of first support wires, and the other end being connected to the stent body, such that the plurality of first support wires protrude outward from the stent body, the maximum diameter of the first structure being greater than the minimum diameter of the channel body; when the fixing structure loses its fixing function, the plurality of first support wires are straight, and the average diameter of the first structure is less than the average diameter of the channel body.

[0006] Furthermore, the fixing structure includes a biodegradable material, and the degradation rate of the fixing structure is greater than the degradation rate of the scaffold body.

[0007] Furthermore, the channel body includes a second support wire, which includes a non-degradable traction wire and a degradable support layer. The degradation rate of the support layer is greater than the degradation rate of the first structure and less than or equal to the degradation rate of the fixed structure.

[0008] Furthermore, the outer side of the support layer includes a hydrogel layer.

[0009] Furthermore, the hydrogel layer includes at least one of styraxomil, paclitaxel, rapamycin, dexamethasone, doxycycline, and iodine-125 particles.

[0010] Furthermore, the pitch of the second structure is 10 mm to 40 mm, and the inner diameter of the helix is ​​6 mm to 15 mm.

[0011] Furthermore, the pitch of the second structure gradually increases in the direction from the first structure to the second structure.

[0012] Furthermore, the diameter of the channel body gradually increases from the end closer to the first structure to the end farther away from the first structure.

[0013] Furthermore, the support body also includes a third structure, the diameter of which gradually increases from the end connected to the second structure to the end away from the second structure.

[0014] Furthermore, the fixing structure includes adhesive or binding wire.

[0015] Furthermore, the material of the stent body includes barium sulfate, basic bismuth carbonate, bismuth trioxide, or bismuth oxychloride.

[0016] Secondly, this invention also provides a method for fabricating a biliary stent, comprising the following steps: In the first stage, a stent body is fabricated. The stent body comprises a first structure and a second structure sequentially from one end to the other. The second structure includes a channel body that maintains a spatial spiral in its natural state, and the channel body includes a guide cavity. The first structure includes a first support ring and multiple first support wires. The first support ring and the multiple first support wires are fabricated using 3D printing equipment. One end of each of the multiple first support wires is connected to the first support ring, and the other end of each of the multiple first support wires is connected to the second structure. The diameter of the first support ring is greater than or equal to the diameter of the channel body near the first structure. The diameter of one end of the first structure is half that of the first structure and smaller than the diameter of the end of the channel body closest to the first structure. The multiple first support wires are straight, and the average diameter of the first structure is smaller than the average diameter of the second structure. In the second stage, after the multiple first support wires cool and solidify, an external force mechanism is used to make the multiple first support wires bulge outward from the support body. The maximum diameter of the first structure is greater than the minimum diameter of the channel body. In the third stage, a fixing structure is prepared, and one end of the fixing structure is connected to the first support ring and / or the multiple first support wires, and the other end is connected to the support body, so that the multiple first support wires remain bulging outward from the support body.

[0017] Furthermore, the preparation of the fixing structure includes: using a hot-melt process to bond the first support ring and / or the plurality of first support wires and the bracket body with a biodegradable material; or, using biodegradable wire to connect the first support ring and / or the plurality of first support wires and the bracket body.

[0018] The embodiments of the present invention have at least the following technical effects:

[0019] This invention provides a biliary stent, the stent body comprising a first structure and a second structure from one end to the other. The second structure includes a channel body that maintains a spatial spiral in its natural state. The channel body includes a guide cavity for the guide wire to pass through and for fluid to flow through. When the stent is placed in the bile duct, the direction from the first structure to the second structure is from the duodenal papilla towards the gallbladder. Since the human bile duct descends, the stent itself is easy to move downwards. The first structure of the stent body includes a first support ring and multiple first support wires. The multiple first support wires are kept in a state of bulging outwards from the stent body under the action of the fixing structure, which makes the maximum diameter of the first structure larger than the minimum diameter of the second structure. The larger diameter first ring... The stent, located within the bile duct, is easily blocked by the duodenal papilla, preventing it from falling out of the bile duct and into the duodenum. The superimposed spiral channel body further helps maintain the stent's relative stability after placement in the bile duct, minimizing its movement. When the fixation structure loses its fixation function, the curved first support wire straightens and pushes the first support ring outward. The length of the first structure increases, bringing the first support ring, which was originally in the bile duct, closer to the duodenal papilla, or even through it. The first support ring is exposed in the intestine, facilitating the entire stent's self-expansion. During this dynamic ejection process, the annular end is less likely to scratch the bile duct or the intestine upon subsequent entry.

[0020] Meanwhile, the diameter of the first support ring is greater than or equal to half the diameter of the end of the second structure closest to the first structure, and less than or equal to the diameter of the end of the second structure closest to the first structure. This means that after the fixation structure degrades, the diameter of the first structure near the duodenal papilla is smaller than the diameter of the second structure. Since the human bile duct naturally points downwards, the smaller diameter of the first structure is more conducive to the stent's spontaneous expulsion from the bile duct. Furthermore, because the spiral channel body, even when needing to conform to the bile duct's direction, is more easily relieved of stress due to the spiral gaps, it is less prone to breakage, increasing the overall flexibility of the stent. This also allows the stent to be expelled from the bile duct before the fixation structure loses its fixation function and before it degrades to the point of producing large fragments. Therefore, it avoids the formation of large fragments of the stent inside the bile duct, and even if the fixation structure degrades, it produces small fragments that will not damage the bile duct.

[0021] In this embodiment, when the stent is inserted, the first structure has a larger diameter and the second structure is spiral-shaped to prevent the stent from shifting after being inserted into the bile duct. After the support function is completed, the fixing structure loses its fixing function first, and the stent body has not yet degraded, which prevents the stent from forming large fragments inside the bile duct. At the same time, it also makes the curved first support wire straight. The average diameter of the first structure is smaller than the average diameter of the second structure, which is conducive to the stent being discharged outward on its own and avoids the adverse effects that would occur if it remained in the bile duct and continued to degrade. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the first example of a biliary stent structure provided in an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the second-view structure of the first example of a biliary stent provided in an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the third-view structure of the first example of a biliary stent provided in an embodiment of the present invention;

[0026] Figure 4 This is a partial schematic diagram of the first structure of the biliary stent provided in an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of a first cross-section of the second support wire of the biliary stent provided in an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of a second cross-section of the second support wire of the biliary stent provided in an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of a third cross-section of the second support wire of the biliary stent provided in an embodiment of the present invention;

[0030] Figure 8 This is a schematic diagram of a second biliary stent structure provided in an embodiment of the present invention.

[0031] Icons: 2-Fixed structure; 11-First structure; 12-Second structure; 121-Channel body; 111-First support ring; 112-First support wire; 1211-Second support wire; 12111-Traction wire; 12112-Support layer; 12113-Hydrogel layer. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0034] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0035] For the first aspect, please refer to Figures 1 to 4 This invention provides a biliary stent, comprising: a stent body, which includes a first structure 11 and a second structure 12 sequentially from one end to the other; the second structure 12 includes a channel body 121 that maintains a spatial spiral in its natural state, the channel body including a guide cavity for a guide wire to pass through and for fluid to flow through; the stent body is made of a biodegradable material; the first structure 11 includes a first support ring 111 and multiple first support wires 112, one end of each first support wire 112 being connected to the first support ring 111, and the other end of each first support wire 112 being connected to the second structure 12; the first support ring 111 has a large diameter. The diameter of the first structure 11 is equal to half the diameter of the end of the channel body 121 near the first structure 11 and less than or equal to the diameter of the end of the channel body 121 near the first structure 11; the fixing structure 2 has one end connected to the first support ring 111 and / or multiple first support wires 112, and the other end connected to the bracket body, such that the multiple first support wires 112 bulge outward from the bracket body, and the maximum diameter of the first structure 11 is greater than the minimum diameter of the channel body 121; when the fixing structure 2 loses its fixing function, the multiple first support wires 112 are straight, and the average diameter of the first structure 11 is less than the average diameter of the channel body 121.

[0036] In this embodiment, the stent body includes a first structure 11 and a second structure 12 sequentially from one end to the other. The second structure 12 includes a channel body 121 that maintains a spatial spiral in its natural state. The channel body includes a guide cavity for the guide wire to pass through and for fluid to flow through. When the stent is placed in the bile duct, the direction from the first structure 11 to the second structure 12 is from the duodenal papilla towards the gallbladder. Since the bile duct in the human body is downward, the stent itself is easy to move downward. The first structure 11 of the stent body includes a first support ring 111 and multiple first support wires 112. The multiple first support wires 112 are kept in a state of bulging outward from the stent body under the action of the fixing structure 2. This makes the maximum diameter of the first structure larger than the minimum diameter of the second structure. The larger diameter of the first structure 111... 1. Located within the bile duct, the stent is easily blocked by the duodenal papilla, preventing it from falling out of the bile duct and into the duodenum. The superimposed spiral channel body 121 further helps the stent maintain a relatively stable state after being placed in the bile duct, minimizing movement within the bile duct. When the fixing structure 2 loses its fixing function, the curved first support wire 112 becomes straight and also causes the first support ring 111 to pop outward. The length of the first structure 11 increases, making the first support ring 111, which was originally in the bile duct, closer to the duodenal papilla, or even passing through the duodenal papilla. The first support ring 111 is exposed in the intestine, facilitating the entire stent to be expelled outward on its own. During this dynamic popping process, the annular end is less likely to scratch the bile duct or the intestine when it enters the intestine.

[0037] Meanwhile, the diameter of the first support ring 111 is greater than or equal to half the diameter of the end of the second structure 12 closest to the first structure 11, and less than or equal to the diameter of the end of the second structure 12 closest to the first structure 11. This means that after the fixation structure 2 degrades, the diameter of the first structure 11 closest to the duodenal papilla is smaller than the diameter of the second structure 12. Since the human bile duct is downward-facing, the smaller diameter of the first structure 11 is more conducive to the stent being discharged out of the bile duct on its own. At the same time, because the spiral channel body 121, even if it needs to follow the direction of the bile duct, is more likely to be unloaded due to the gaps in the spiral, it is not easy to break, increasing the overall flexibility of the stent. It also allows the stent body to be discharged out of the bile duct before the fixation structure 2 loses its fixation function and before it degrades to the point of producing large fragments. Therefore, it avoids the formation of large fragments of the stent inside the bile duct. Even if the fixation structure 2 degrades, it will produce small fragments that will not damage the bile duct.

[0038] In this embodiment, when the stent is inserted, the first structure 11 has a larger diameter and the second structure 12 is spiral-shaped to prevent the stent from shifting after being inserted into the bile duct of the human body. After the support function is completed, the fixing structure 2 loses its fixing function first, and the stent body has not yet degraded, which prevents the stent from forming large fragments inside the bile duct. At the same time, it also makes the curved first support wire 112 straight. The average diameter of the first structure 11 is smaller than the average diameter of the second structure 12, which is conducive to the stent being discharged outward by itself and avoids the adverse effects that would occur if it remained in the bile duct and continued to degrade.

[0039] Optionally, the fixation structure 2 includes a biodegradable material, and the degradation rate of the fixation structure 2 is greater than that of the first structure 11. In this embodiment, the fixation structure 2 is also made of a biodegradable material, so the degradation rate of the first structure 11 is less than that of the fixation structure 2. When the fixation structure 2 is not degrading, the multiple first support wires 112 remain raised. As the fixation structure 2 gradually degrades, the multiple first support wires 112 that are raised outwards will become straight support wires, which is conducive to discharge to the outside of the bile duct, thus avoiding the formation of large fragments of the stent inside the bile duct.

[0040] Optional, please continue reading Figures 5 to 7 The channel body 121 includes a second support wire 1211, which includes a non-degradable traction wire 12111 and a degradable support layer 12112. The degradation rate of the support layer 12112 is greater than that of the first structure 11 and less than or equal to that of the fixed structure 2. In this embodiment, considering that if the spiral second structure does not degrade or degrades very little, it may still remain in the bile duct due to high friction, the second support wire 1211 forming the channel body 121 includes a non-degradable and soft traction wire 12111 and a degradable and relatively hard support layer 12112. The degradation rate of the support layer 12112 is greater than the degradation rate of the first structure 11 and less than or equal to the degradation rate of the fixing structure 2. This means that when the fixing structure 2 loses its fixing function, the channel body 121 also degrades and collapses. However, since the support layer 12112 is attached to the traction wire 12111, even if the support layer 12112 degrades, no fragments will be generated in the bile duct, thus better preventing the generation of fragments. After the channel body 121 degrades and collapses, since the degradation rate of the support layer 12112 is greater than the degradation rate of the first structure 11, the first structure 11 has not yet degraded and remains a relatively hard, linear structure, which facilitates the outward discharge of the collapsed channel body 121.

[0041] The support layer 12112 can either partially or fully enclose the traction wire 12111. Preferably, the degradation rate of the support layer 12112 is equal to the degradation rate of the fixing structure 2. When the fixing structure 2 fails, the channel body 121 also loses its supporting function, and the support can be smoothly discharged. Preferably, the support layer 12112 gradually transitions from partially enclosing the traction wire 12111 to fully enclosing it from the end closest to the first structure 11 to the end furthest from the first structure 11. The supporting effect is stronger when fully enclosed than when partially enclosed. Because the diameter of the first structure 11 is larger and the support is stronger when the first support wire 112 bulges outward, the second support wire 12111 close to the first structure 11 can benefit from the supporting effect of the first structure 11, while the second support wire 12111 furthest from the first structure 11 requires the support layer 12112 to fully enclose the traction wire 12111 to provide a good supporting effect. This not only reduces material costs, but also makes the second structure 12 more flexible near the first structure 11 during the outward discharge process after the support has completed its supporting function. Under the action of the first structure 11, it is better discharged outward.

[0042] Optionally, the outer side of the support layer 12112 includes a hydrogel layer 12113. In this embodiment, attaching a hydrogel layer 12113 to the outer side of the support layer 12112 can increase the adhesion of the second structure 12 in the bile duct during the period when the stent is providing support, making the stent more stably supported in the bile duct. At the same time, the hydrogel will gradually degrade over time and will not affect the subsequent stent removal process. The hydrogel layer 12113 can either partially or fully cover the support layer 12112. When the hydrogel layer 12113 partially covers the support layer 12112, the side coated with the hydrogel layer 12113 contacts the inner wall of the bile duct.

[0043] Optionally, the hydrogel layer includes at least one of the following: sclerosingmycin, paclitaxel, rapamycin, dexamethasone, doxycycline, and iodine-125 particles. In this embodiment, various drugs are added to the hydrogel to facilitate better therapeutic effects while the scaffold provides support. For example, paclitaxel and iodine-125 have anticancer effects, dexamethasone and rapamycin have anti-inflammatory and body-regulating effects, doxycycline has effective antibacterial properties, and sclerosingmycin can reduce tumor-induced hypercalcemia.

[0044] Optionally, the pitch of the second structure 12 is 10 mm to 40 mm, and the inner diameter of the helix is ​​6 mm to 15 mm. In this embodiment, the pitch D of the second structure 12 needs to be maintained at 10 mm to 40 mm, and the inner diameter d is 6 mm to 15 mm. These two components work together to ensure that the stent does not shift in the early stages and is easily discharged later, while also not affecting drainage. For example, if the pitch D is less than 10 mm, the second structure 12 will encounter too much obstruction during the subsequent stent discharge process, making it difficult to discharge; if it is greater than 40 mm, the second structure 12 will not be effective in preventing stent displacement within the bile duct. It should be noted that the pitch of the second structure 12 here does not only refer to... Figure 1 The pitch D shown refers to the axial distance between two points on the pitch diameter of any two adjacent teeth on the helix. The more turns the helix has, the more the axial distance between two points on the pitch diameter of any two adjacent teeth needs to be between 10 mm and 40 mm.

[0045] Optionally, the pitch of the second structure 12 gradually increases in the direction from the first structure 11 to the second structure 12. In this embodiment, the gradually increasing pitch can make the front section of the bracket stronger and the rear section relatively flexible, which is more conducive to subsequent automatic outward discharge.

[0046] Optional, please refer to Figure 8 The diameter of the channel body 121 gradually increases from the end closest to the first structure 11 to the end furthest from the first structure 11. In this embodiment, the channel body 121 is a structure whose diameter gradually increases from the first structure 11 to the second structure 12. The minimum diameter of the channel body 121 needs to be smaller than the maximum diameter of the first structure 11 (before the fixation structure 2 degrades). This arrangement is more conducive to keeping the stent in the bile duct and facilitating bile outflow. The specific characteristics of the second structure are not limited here; for example, the second structure can be a mesh structure or other structures that can form a similar cylindrical shape. The diameter of the overall cylindrical shape can be uniform or gradually increasing.

[0047] Optionally, the stent body also includes a third structure, the diameter of which gradually increases from the end connected to the second structure to the end away from the second structure. In this embodiment, if the diameter of the spiral channel of the second structure is uniform, the third structure is a structure whose diameter gradually increases in the direction from the first structure to the third structure. The diameter at the connection between the third structure and the second structure is the smallest diameter, which is more conducive to keeping the stent in the bile duct without moving. The material of the support wires constituting the third structure is the same as the material of the second support wires. The specific characteristics of the third structure are not limited here; for example, the third structure can be a mesh structure or other structures that can form a similar cylindrical shape, as long as the diameter of the overall cylindrical shape gradually increases.

[0048] Optionally, the fixing structure 2 includes adhesive bonding or binding wire. In this embodiment, the fixing structure may be made of a biodegradable material to bond the first support ring 111 or the first support wire 112 to one end near the first support ring 111, or the first support ring 111 and the first support wire 112 to one end near the first support ring 111, and the first support wire 112 to one end near the second structure 12, or the inner side of the second structure 12, so that the first support wire 112 remains raised; or, biodegradable wire may be used to bind the first support ring 111 or the first support wire 112 to one end near the first support ring 111, or the first support ring 111 and the first support wire 112 to one end near the first support ring 111, and the first support wire 112 to one end near the second structure 12, or the second structure 12, so that the first support wire 112 remains raised.

[0049] Optionally, the material of the stent body includes barium sulfate, basic bismuth carbonate, bismuth trioxide, or bismuth oxychloride. In this embodiment, adding a developing agent such as barium sulfate, basic bismuth carbonate, bismuth trioxide, or bismuth oxychloride to the material of the stent body is beneficial for positioning during stent placement and for subsequent observation. Preferably, the material of the first structure includes a developing agent, which is beneficial for observing the morphological changes of the first structure, thereby determining the stent discharge status.

[0050] Secondly, embodiments of the present invention provide a method for preparing a biliary stent, comprising the following steps: In the first stage, a stent body is prepared. The stent body includes a first structure 11 and a second structure 12 sequentially from one end to the other. The second structure 12 includes a channel body 121 that maintains a spatial spiral in its natural state, and the channel body 121 includes a guide cavity. The first structure 11 includes a first support ring 111 and multiple first support wires 112. The first support ring 111 and multiple first support wires 112 are prepared using 3D printing equipment. One end of each of the multiple first support wires 112 is connected to the first support ring 111, and the other end of each of the multiple first support wires 112 is connected to the second structure 12. The diameter of the first support ring 111 is greater than or equal to half the diameter of the end of the channel body 121 closest to the first structure 11, and less than the diameter of the end of the channel body 121 closest to the first structure 11. The multiple first support wires 112 are straight, and the average diameter of the first structure 11 is less than the average diameter of the channel body 121.

[0051] In the second stage, after the multiple first support wires 112 have cooled and solidified, an external force mechanism causes the multiple first support wires 112 to bulge outwards from the support body. The maximum diameter of the first structure 11 is greater than the minimum diameter of the channel body 121.

[0052] In the third stage, a fixing structure 2 is prepared, one end of the fixing structure 2 is connected to a first support ring 111 and / or multiple first support wires 112, and the other end is connected to the support body, so that the multiple first support wires 112 remain raised to the outside of the support body.

[0053] In this embodiment, firstly, the first structure 11 and the second structure 12 of the support body are prepared, and the first support ring 111 and multiple straight first support wires 112 are prepared using 3D printing equipment. In the second stage, after the straight first support wires 112 solidify, they are bent outward by external force. Specifically, the connection between the first structure 11 and the second structure 12 of the support body is fixed at a certain position, and then the first support ring 111 is moved in the direction where the first structure 11 points to the second structure 12. At this time, the straight first support wires 112 will bulge outward due to the mechanical properties of the material itself. In the third stage, a fixing structure 2 is prepared. This fixing structure 2 can keep the multiple first support wires bulging outward towards the outside of the support body. If the fixation structure 2 is made of a biodegradable material, its degradation rate is greater than that of the stent body. Therefore, after insertion into the bile duct, the fixation structure 2 first loses its fixation function, and the raised first support wire 112 will naturally return to its initial straight state. Furthermore, because the diameter of the first support ring 111 is greater than or equal to half the diameter of the end of the channel body 121 near the first structure 11, and smaller than the diameter of the end of the channel body 121 near the first structure 11, the diameter of the first structure 11 will become smaller than the diameter of the channel body 121, which facilitates the stent's self-extraction from the bile duct. The diameter of the first support ring 111 should not be too small, otherwise it may affect the normal flow of bile. Optionally, the preparation of the fixation structure 2 includes: using a hot-melt process to bond the first support ring 111 and / or multiple first support wires 112, and the stent body with a biodegradable material; and using biodegradable wires to connect the first support ring 111 and / or multiple first support wires 112, and the stent body.

[0054] In this embodiment, since the first structure 11 and the second structure 12 have been prepared in the first stage, one end of the fixing structure 2 can be connected to the first support ring 111, or the end of the first support wire 112 near the first support ring 111, or the end of the first support ring 111 and the first support wire 112 near the first support ring 111, and the other end is connected to the end of the first support wire 112 away from the first support ring 111, or to the second structure 12, so that multiple first support wires 112 remain raised towards the outside of the bracket body. Specifically, a hot melt process is used to bond them with biodegradable materials or biodegradable wires are used for connection.

[0055] Optionally, when preparing the second structure 12, the traction wire 12111 is first fixed to the first structure 11, and then the biodegradable support layer 12112 is partially or fully wrapped around the traction wire 12111 by 3D printing.

[0056] The structure of the biliary stent in the preparation method of the biliary stent described in this embodiment is the same as that of the biliary stent described in the first aspect. Therefore, for details not covered in this embodiment, please refer to the first aspect and... Figures 1 to 8 The specific details will not be elaborated here.

[0057] Thirdly, embodiments of the present invention provide a method for preparing a biliary stent, the steps of which are as follows:

[0058] In the first stage, the scaffold body is prepared. The scaffold body includes a first structure 11 and a second structure 12 from one end to the other. The first structure 11 and the second structure 12 are prepared separately. The second structure 12 includes a channel body 121 that maintains a spatial spiral in its natural state. The channel body 121 includes a guide cavity. The first structure includes a first support ring 111 and multiple first support wires 112. The first support ring 111 and multiple first support wires 112 are prepared using 3D printing equipment. One end of the multiple first support wires 112 is connected to the first support ring 111. The diameter of the first support ring 111 is greater than or equal to half the diameter of the end of the channel body 121 near the first structure 11 and less than the diameter of the end of the channel body 121 near the first structure 11. The multiple first support wires 112 are straight. The average diameter of the first structure 11 is less than the average diameter of the channel body 121.

[0059] In the second stage, after the multiple first support wires 112 have cooled and solidified, an external force mechanism is used to make the multiple first support wires 112 bulge outwards from the support body, and the maximum diameter of the first structure 11 is greater than the minimum diameter of the channel body 121; in the third stage, a fixing structure 2 is prepared, and one end of the fixing structure 2 is connected to the first support ring 111 and / or the side of the multiple first support wires 112 close to the first support ring 111, and the other end is connected to the side of the multiple first support wires 112 away from the first support ring 111, so that the multiple first support wires 112 continue to bulge outwards from the support body; in the fourth stage, the other end of the multiple first support wires 112 is connected to the second structure 12.

[0060] In this embodiment, the difference from the above embodiment is that the first structure 11 and the second structure 12 can be manufactured separately. After the first support wire 112 in the first structure 11 is kept to bulge outward from the support body by the fixing structure 2, the first structure 11 and the second structure 12 are then connected together. The advantage of doing so is that it is more efficient and avoids the impact on the second structure 12 in the second or third stage.

[0061] The structure of the biliary stent in the preparation method of the biliary stent described in this embodiment is the same as that of the biliary stent described in the first aspect. Therefore, for details not covered in this embodiment, please refer to the first aspect and... Figures 1 to 8 The specific details will not be elaborated here.

[0062] Fourthly, embodiments of the present invention provide a method for preparing a biliary stent, the steps of which are as follows:

[0063] In the first stage, the first structure 11 of the scaffold body is prepared; wherein, the first structure 11 includes a first support ring 111 and multiple first support wires 112. The first support ring 111 and multiple first support wires 112 are prepared by 3D printing equipment. One end of the multiple first support wires 112 is connected to the first support ring 111, and the multiple first support wires 112 are in a straight line.

[0064] In the second stage, after the multiple first support wires 112 have cooled and solidified, an external force mechanism is used to make the multiple first support wires 112 bulge outwards from the support body.

[0065] In the third stage, a fixing structure 2 is prepared, and one end of the fixing structure 2 is connected to the first support ring and / or the side of multiple first support wires 112 close to the first support ring 111, and the other end is connected to the side of multiple first support wires 112 away from the first support ring 111, so that the multiple first support wires 112 remain raised towards the outside of the support body.

[0066] In the fourth stage, a second structure 12 of the support body is prepared along the end of the multiple first support wires 112 away from the first support ring 111. The second structure 12 includes a channel body 121 that maintains a spatial spiral in its natural state. The diameter of the first support ring 111 is greater than or equal to half the diameter of the end of the channel body 121 near the first structure 11 and less than the diameter of the end of the channel body 121 near the first structure 11.

[0067] In this embodiment, the difference from the above embodiment is that the first structure 11 is printed first, and then the first support wire 112 in the first structure 11 is kept to bulge outward from the support body by the fixing structure 2. Then the other end of the first support wire 112 is used to prepare the second structure 12, which also avoids the influence on the second structure 12 in the second or third stage.

[0068] The structure of the biliary stent in the preparation method of the biliary stent described in this embodiment is the same as that of the biliary stent described in the first aspect. Therefore, for details not covered in this embodiment, please refer to the first aspect and... Figures 1 to 8 The specific details will not be elaborated here.

[0069] Those skilled in the art will understand that the steps, measures, and schemes in the various operations, methods, and processes discussed in this invention can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and schemes in the various operations, methods, and processes discussed in this invention can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and schemes in the prior art that are similar to those disclosed in this invention can also be alternated, modified, rearranged, decomposed, combined, or deleted.

[0070] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are 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.

[0071] 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 one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0072] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0073] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A biliary stent, characterized by, Comprising: a stent body, the stent body comprising a first structure and a second structure in sequence from one end to another end, the second structure comprising a channel body maintaining a spatial spiral in a natural state, the channel body comprising a guide lumen for a guide wire to pass through and a fluid to flow through, the stent body comprising a degradable material; the first structure comprising a first support ring, a plurality of first support wires, one end of the plurality of first support wires being connected with the first support ring, the other end of the plurality of first support wires being connected with the second structure, the diameter of the first support ring being greater than or equal to one half of the diameter of one end of the channel body close to the first structure and less than the diameter of one end of the channel body close to the first structure; a fixing structure, one end of the fixing structure being connected with the first support ring and / or the plurality of first support wires, the other end of the fixing structure being connected with the stent body, so that the plurality of first support wires protrude outwardly to the stent body, the maximum diameter of the first structure being greater than the minimum diameter of the channel body; when the fixing structure loses the fixing function, the plurality of first support wires are in a straight line type, the average diameter of the first structure being less than the average diameter of the channel body; the fixing structure comprising a degradable material, the degradation rate of the fixing structure being greater than the degradation rate of the stent body.

2. The biliary stent of claim 1, wherein, the channel body comprising a second support wire, the second support wire comprising a non-degradable traction line and a degradable support layer, the degradation rate of the support layer being greater than the degradation rate of the first structure and less than or equal to the degradation rate of the fixing structure.

3. The biliary stent of claim 2, wherein, the outer side of the support layer comprising a hydrogel layer.

4. The biliary stent of claim 3, wherein, at least one of puromycin, paclitaxel, rapamycin, dexamethasone, doxycycline, and iodine 125 particles is included in the hydrogel layer.

5. The biliary stent of claim 1, wherein, the pitch of the second structure is 10 mm to 40 mm, and the inner diameter of the spiral is 6 mm to 15 mm.

6. The biliary stent of claim 5, wherein, the pitch of the second structure gradually increases in the direction in which the first structure points to the second structure.

7. The biliary stent of claim 5, wherein, the diameter of the channel body gradually increases from one end close to the first structure to the other end away from the first structure.

8. The biliary stent of claim 1, wherein, the stent body further comprises a third structure, the diameter of the third structure gradually increases from one end connected with the second structure to the other end away from the second structure.

9. The biliary stent of claim 1, wherein, the fixing structure comprises an adhesive or a binding wire.

10. The biliary stent of claim 1, wherein, the material of the stent body comprises barium sulfate, or basic bismuth carbonate, or bismuth trioxide, or bismuth oxychloride.

11. A method of manufacturing a biliary stent, characterized by, The steps are as follows: a first stage, a stent body is prepared, the stent body comprising a first structure and a second structure in sequence from one end to another end, the second structure comprising a channel body maintaining a spatial spiral in a natural state, the channel body comprising a guide lumen; The first structure comprises a first support ring and a plurality of first support wires, the first support ring and the plurality of first support wires are prepared by using a 3D printing device, one end of the plurality of first support wires is connected with the first support ring, the other end of the plurality of first support wires is connected with the second structure, the diameter of the first support ring is greater than or equal to one-half of the diameter of the one end of the channel body close to the first structure and less than the diameter of the one end of the channel body close to the first structure, the plurality of first support wires are in a straight line type, and the average diameter of the first structure is less than the average diameter of the second structure. In the second stage, after the plurality of first support wires are cooled and solidified, an external force mechanism is used to make the plurality of first support wires protrude outwardly from the stent body, and the maximum diameter of the first structure is greater than the minimum diameter of the channel body. In the third stage, a fixing structure is prepared, one end of the fixing structure is connected with the first support ring and / or the plurality of first support wires, and the other end of the fixing structure is connected with the stent body, so that the plurality of first support wires protrude outwardly from the stent body; the fixing structure comprises a degradable material, and the degradation rate of the fixing structure is greater than the degradation rate of the stent body.

12. The method of claim 11, wherein the biliary stent is prepared by the steps of: The preparation of the fixing structure comprises: using a hot melting process to bond the first support ring and / or the plurality of first support wires and the stent body by using a degradable material; or, using a degradable wire to connect the first support ring and / or the plurality of first support wires and the stent body.

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