Biliary tract stent and preparation method thereof

Abstract

The invention relates to the technical field of medical instruments, and provides a biliary tract stent and a preparation method thereof.The biliary tract stent comprises a stent body, the stent body sequentially comprises a first structure and a second structure from one end to the other end, and the second structure comprises a channel body keeping spatial spiral in the natural state; the first structure comprises a first supporting ring and a plurality of first supporting wires; one end of the fixing structure is connected with the first supporting ring and / or the first supporting wires, the other end of the fixing structure is connected with the support body, the first supporting wires protrude towards the outer side of the support body, and the maximum diameter of the first structure is larger than the minimum diameter of the channel body; when the fixing structure loses the fixing function, the first supporting wires are linear, and the average diameter of the first structure is smaller than that of the channel body. According to the biliary tract stent, the technical problems that in the prior art, a stent is prone to displacement and breakage to form large stent fragments and is difficult to discharge subsequently are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a biliary tract stent and a preparation method thereof. BACKGROUND

[0002] If the existing biliary tract stent is made of non-degradable material, a secondary surgery is needed to remove it after its function is completed, which increases the pain of the patient; in order to avoid the secondary surgery, a degradable biliary tract stent is a better choice. However, there are still some problems to be solved in the existing degradable stent. One of them is that the degradable stent is prone to displacement. In addition, the degradable biliary tract stent may be broken into irregular large fragments in the biliary tract during the degradation process, such as irregularly breaking from the middle of the stent to form two larger stent fragments, which may injure the biliary tract and even the pancreas; in addition, due to the degradation period of the degradable material, it is difficult to discharge the larger stent fragments after the stent completes its support mission, which may lead to complications, which is not beneficial to the patient.

[0003] Therefore, there is a need for a biliary tract stent which is not prone to displacement in the early stage after implantation, reduces the generation of larger fragments in the biliary tract during the support process in the later stage, and can be discharged as soon as possible after the support is completed. SUMMARY

[0004] The present application aims to provide a biliary tract stent and a preparation method thereof, so as to solve the technical problems of the existing art that the stent is prone to displacement, prone to breaking into larger stent fragments, and difficult to discharge subsequently.

[0005] In a first aspect, the embodiments of the present application provide a biliary tract stent, comprising: a stent body, the stent body comprising a first structure and a second structure in sequence from one end to the other end, the second structure comprising a channel body maintaining a space spiral in a natural state, the channel body comprising a guide lumen for guiding a guide wire to pass through and for 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 of 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.

[0006] Further, the fixing structure comprises a degradable material, and a degradation rate of the fixing structure is greater than a degradation rate of the stent body.

[0007] Further, the channel body comprises a second support wire, and the second support wire comprises a non-degradable traction line and a degradable support layer, and a degradation rate of the support layer is greater than a degradation rate of the first structure and less than or equal to a degradation rate of the fixing structure.

[0008] Further, an outer side of the support layer comprises a hydrogel layer.

[0009] Further, the hydrogel layer comprises at least one of puromycin, paclitaxel, rapamycin, dexamethasone, doxycycline, and Iodine-125 particles. Further, a pitch of the second structure is 10 mm to 40 mm, and an inner diameter of the second structure is 6 mm to 15 mm.

[0010] Further, the pitch of the second structure gradually increases in a direction in which the first structure points to the second structure.

[0011] Further, a diameter of the channel body gradually increases from one end close to the first structure to one end away from the first structure.

[0012] Further, the stent body further comprises a third structure, and a diameter of the third structure gradually increases from one end connected to the second structure to one end away from the second structure.

[0013] Further, the fixing structure comprises an adhesive or a binding wire.

[0014] Further, a material of the stent body comprises barium sulfate, or basic bismuth carbonate, or bismuth trioxide, or bismuth oxychloride.

[0015] In a second aspect, the embodiments of the present application also provide a preparation method of the biliary tract stent, comprising the following steps: in a first stage, a stent body is prepared, the stent body comprises a first structure and a second structure in sequence from one end to another end, the second structure comprises a channel body maintaining a space spiral in a natural state, and the channel body comprises a guide cavity; wherein 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 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, the average diameter of the first structure is less than the average diameter of the second structure; in a 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 to the outside of the stent body, and the maximum diameter of the first structure is greater than the minimum diameter of the channel body; in a 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 are kept protruding to the outside of the stent body.

[0016] Further, 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.

[0017] The embodiments of the present application have at least the following technical effects: The biliary tract stent provided by the embodiment of the present application comprises a first structure, a second structure and a channel body in a spiral shape in a natural state, wherein the channel body comprises a guide cavity for guiding a guide wire to pass through and for fluid to flow through; the stent is placed in the biliary tract in a direction from the first structure to the second structure, which is a direction in which the duodenal papilla points to the gallbladder; the biliary tract of the human body is downward, so the stent itself is prone to moving downward; the first structure of the stent body comprises a first support ring and a plurality of first support wires, which are kept in a state of bulging outwardly under the action of a fixing structure, so that the maximum diameter of the first structure is greater than the minimum diameter of the second structure; the first structure with a larger diameter is located in the biliary tract and is prone to being blocked by the duodenal papilla, thereby preventing the stent from falling out of the biliary tract and entering the duodenum; the spiral channel body can better enable the stent to maintain a relatively stable state after being placed in the biliary tract, thereby avoiding movement of the stent in the biliary tract; when the fixing structure loses the fixing function, the curved first support wires become straight and also drive the first support ring to pop out outwardly; the length of the first structure becomes longer, so that the first support ring originally in the biliary tract is closer to the duodenal papilla or even penetrates through the duodenal papilla; the first support ring is exposed in the intestinal tract, thereby facilitating the entire stent to be discharged outwardly by itself; and the annular end portion is not prone to scratching the biliary tract and the intestinal tract subsequently entered.

[0018] Meanwhile, the diameter of the first support ring is greater than or equal to one-half of the diameter of one end of the second structure close to the first structure and less than or equal to the diameter of the one end of the second structure close to the first structure, which means that the diameter of the first structure close to the duodenal papilla is smaller than the diameter of the second structure after the fixing structure degrades; because the biliary tract of the human body is downward, the first structure with a smaller diameter is more conducive to the stent being discharged outwardly from the biliary tract by itself. Meanwhile, because the spiral channel body is easier to unload force and is not prone to breaking due to the gap of the spiral, the overall flexibility of the stent is increased; the stent body is discharged outwardly from the biliary tract before the fixing structure loses the fixing function and degrades into larger fragments, so that the stent does not form larger fragments in the biliary tract; and the fixing structure degrades into small fragments, which will not damage the biliary tract.

[0019] In the embodiment, the diameter of the first structure is larger and the second structure is in a spiral shape when the stent is placed, so as to avoid displacement of the stent after being placed in the biliary tract of the human body; after the supporting function is completed, the fixing structure loses the fixing function before the stent body degrades, so as to avoid the stent forming larger fragments in the biliary tract and also to enable the curved first support wires to become straight, so that 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 outwardly by itself and avoids the adverse effects caused by the stent remaining in the biliary tract and continuing to degrade. Attached Figure Description

[0020] 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.

[0021] Figure 1 This is a schematic diagram of the first example of a biliary stent structure provided in an embodiment of the present invention. 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; 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; Figure 4 This is a partial schematic diagram of the first structure of the biliary stent provided in an embodiment of the present invention; 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; 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; 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; Figure 8 This is a schematic diagram of a second biliary stent structure provided in an embodiment of the present invention.

[0022] 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

[0023] 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.

[0024] As used herein, and unless otherwise indicated, all technical terms, including terms with acronyms, have the same meaning as commonly understood by one of ordinary skill in the art in the field of the application. As used herein, and unless otherwise indicated, the use of the term "about" in relation to a measurement means that the measurement is likely to vary by ±10% or ±5% of the stated value.

[0025] As used herein, and unless otherwise indicated, the use of the singular includes the plural. As used herein, and unless otherwise indicated, the use of the term "includes" means "comprising" of the stated feature, integer, step, operation, element, and / or component as stated but does not preclude the addition of one or more features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, and unless otherwise indicated, the use of the term "and / or" includes all or any of the associated listed items and all combinations thereof.

[0026] In a first aspect, there is provided Figures 1 to 4 The biliary stent provided by the embodiments of the present application comprises: a stent body, the stent body sequentially comprises a first structure 11 and a second structure 12 from one end to the other end, the second structure 12 comprises a channel body 121 which keeps a spiral in a natural state, the channel body comprises a guide lumen for guiding a guide wire to pass through and for fluid to flow through, and the stent body comprises a degradable material; the first structure 11 comprises a first support ring 111 and a plurality of first support wires 112, one end of the plurality of first support wires 112 is connected with the first support ring 111, and the other end of the plurality of first support wires 112 is connected with the second structure 12, the diameter of the first support ring 111 is greater than or equal to one half of the diameter of one end of the channel body 121 close to the first structure 11 and less than or equal to the diameter of the one end of the channel body 121 close to the first structure 11; a fixing structure 2, one end of the fixing structure 2 is connected with the first support ring 111 and / or the plurality of first support wires 112, and the other end of the fixing structure 2 is connected with the stent body, so that the plurality of first support wires 112 protrude outwardly of the stent 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 the fixing function, the plurality of first support wires 112 are in a straight line type, and the average diameter of the first structure 11 is less than the average diameter of the channel body 121.

[0027] In this embodiment, the stent body sequentially comprises the first structure 11, the second structure 12 from one end to the other end, and the second structure 12 comprises a channel body 121 that keeps a spiral in a natural state, the channel body comprises a guide cavity for guiding a guide wire to pass through and fluid to flow through, the stent is placed in the biliary tract from the first structure 11 to the second structure 12 in the direction of the duodenal papilla pointing to the gallbladder, the biliary tract of the human body is downward, so the stent itself is easy to move downward, the first structure 11 of the stent body comprises a first support ring 111 and a plurality of first support wires 112, the plurality of first support wires 112 keep a state of bulging outward under the action of the fixing structure 2, which makes the maximum diameter of the first structure greater than the minimum diameter of the second structure, the first structure 11 with a larger diameter is located in the biliary tract and is easy to be blocked by the duodenal papilla, preventing the stent from falling out of the biliary tract into the duodenum, and the superimposed spiral channel body 121 can better keep the stent relatively stable after being placed in the biliary tract, and try to avoid the movement of the stent in the biliary tract; when the fixing structure 2 loses the fixing function, the curved first support wire 112 becomes a straight line and also drives the first support ring 111 to pop out outward, the length of the first structure 11 becomes longer, so that the first support ring 111 originally in the biliary tract is closer to the duodenal papilla, or even passes through the duodenal papilla, the first support ring 111 is exposed in the intestinal tract, facilitating the entire stent to be driven to be discharged outward by itself, and the annular end portion is not easy to scratch the biliary tract and the subsequent intestinal tract in the process of dynamic ejection.

[0028] At the same time, the diameter of the first support ring 111 is greater than or equal to one half of the diameter of the end of the second structure 12 close to the first structure 11, and less than or equal to the diameter of the end of the second structure 12 close to the first structure 11, which means that after the degradation of the fixing structure 2, the diameter of the first structure 11 close to the duodenal papilla is smaller than the diameter of the second structure 12, because the biliary tract of the human body itself is downward, so the first structure 11 with a smaller diameter is more conducive to the stent being discharged outward from the biliary tract by itself. At the same time, because the spiral channel body 121 is easier to unload due to the gap of the spiral even if it needs to conform to the biliary tract, it is not easy to break, the overall flexibility of the stent is increased, and when the fixing structure 2 loses the fixing function, the stent body has not been degraded to a state of generating large fragments, so that the stent avoids forming large fragments in the biliary tract, and the fixing structure 2 even degrades to generate small fragments, which will not hurt the biliary tract.

[0029] In this embodiment, when the stent is placed, the diameter of the first structure 11 is larger, and the second structure 12 is in a spiral shape, so as to avoid displacement of the stent after being placed in the biliary tract of the human body; after the supporting function is completed, the fixing structure 2 loses the fixing function first, and the stent body has not yet degraded, so as to avoid that the stent forms large fragments in the biliary tract, and at the same time, the curved first supporting wire 112 becomes a straight line, the average diameter of the first structure 11 is smaller than the average diameter of the second structure 12, which is beneficial to the stent to be discharged outward by itself, and avoids the adverse effects caused by the stent remaining in the biliary tract to continue to degrade.

[0030] Optionally, the fixing structure 2 comprises a degradable material, and the degradation rate of the fixing structure 2 is greater than the degradation rate of the first structure 11. In this embodiment, the fixing structure 2 is also selected to be a degradable material, and the degradation rate of the first structure 11 is smaller than the degradation rate of the fixing structure 2. When the fixing structure 2 has not degraded, the plurality of first supporting wires 112 remain raised, and when the fixing structure 2 gradually degrades, the plurality of first supporting wires 112 raised outward become straight supporting wires, which is beneficial to discharge to the outside of the biliary tract, so as to avoid that the stent forms large fragments in the biliary tract.

[0031] Optionally, please continue to refer to Figures 5 to 7 The channel body 121 comprises a second supporting wire 1211, the second supporting wire 1211 comprises a non-degradable traction line 12111 and a degradable supporting layer 12112, and the degradation rate of the supporting layer 12112 is greater than the degradation rate of the first structure 11 and is less than or equal to the degradation rate of the fixing structure 2. In this embodiment, considering that the spiral second structure may still remain in the biliary tract due to large friction if it is not degraded or is degraded little, the second supporting wire 1211 forming the channel body 121 comprises a non-degradable and soft traction line 12111 and a degradable and relatively hard supporting layer 12112, wherein the degradation rate of the supporting layer 12112 is greater than the degradation rate of the first structure 11 and is less than or equal to the degradation rate of the fixing structure 2, which means that when the fixing structure 2 loses the fixing function, the channel body 121 also degrades and collapses, but since the supporting layer 12112 is attached to the traction line 12111, even if the supporting layer 12112 degrades, fragments will not be generated in the biliary tract, and the generation of fragments is better prevented; after the channel body 121 degrades and collapses, since the degradation rate of the supporting layer 12112 is greater than the degradation rate of the first structure 11, the first structure 11 has not yet degraded and is still a straight and relatively hard structure, which is convenient for the collapsed channel body 121 to be discharged outward.

[0032] The support layer 12112 can be half-wrapped around the pull wire 12111 or fully wrapped around the pull wire 12111. Preferably, the degradation rate of the support layer 12112 is equal to the degradation rate of the fixed structure 2, when the fixed structure 2 fails, the channel body 121 also loses the support function, and the stent can be smoothly discharged. Preferably, the support layer 12112 gradually transitions from half-wrapped around the pull wire 12111 to fully wrapped around the pull wire 12111 from the end close to the first structure 11 to the end away from the first structure 11. The support effect of full wrapping is stronger than that of half wrapping. Since the first support wire 112 bulges outward, the diameter of the first structure 11 is larger and the support is stronger, so the second support wire 1211 close to the first structure 11 can rely on the support effect of the first structure 11, and the second support wire 1211 away from the first structure 11 needs the support layer 12112 to fully wrap the pull wire 12111 to provide good support effect. In this way, not only the material cost can be reduced, but also the stent is more flexible at the position of the second structure 12 close to the first structure 11 during the process of being discharged outward after completing its support function, and is better driven outward by the first structure 11.

[0033] Optionally, the outer side of the support layer 12112 includes a hydrogel layer 12113. In this embodiment, the hydrogel layer 12113 is attached to the outer side of the support layer 12112, which can increase the adhesion of the second structure 12 in the bile duct during the support of the stent, so that the stent is more stably supported in the bile duct. At the same time, with the passage of time, the hydrogel will also gradually degrade and will not affect the subsequent process of discharging the stent. The hydrogel layer 12113 can be half-wrapped around the support layer 12112 or fully wrapped around the support layer 12112. When the hydrogel layer 12113 is half-wrapped around the support layer 12112, the side coated with the hydrogel layer 12113 contacts the inner wall of the bile duct.

[0034] Optionally, the hydrogel layer includes at least one of puromycin, paclitaxel, rapamycin, dexamethasone, doxycycline, and iodine 125 particles. In this embodiment, various drugs are added to the hydrogel to facilitate better therapeutic effect while the stent is supporting. For example, paclitaxel and iodine 125 have anticancer effect, dexamethasone and rapamycin have anti-inflammatory and body state regulating effect, doxycycline can effectively resist bacteria, and puromycin can reduce hypercalcemia caused by tumors.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Optionally, the fixing structure 2 comprises an adhesive or a binding wire. In this embodiment, the fixing structure can be to use a degradable material to bond the first support ring 111, or the first support wire 112 close to the first support ring 111, or the first support ring 111 and the first support wire 112 close to the first support ring 111, to the first support wire 112 close to the second structure 12, or the inner side of the second structure 12, so that the first support wire 112 remains raised; or, to use a degradable wire to bind the first support ring 111, or the first support wire 112 close to the first support ring 111, or the first support ring 111 and the first support wire 112 close to the first support ring 111, to the first support wire 112 close to the second structure 12, or the second structure 12, so that the first support wire 112 remains raised.

[0040] Optionally, the material of the stent body comprises barium sulfate, or bismuth subcarbonate, or bismuth trioxide, or bismuth oxychloride. In this embodiment, the addition of a developer such as barium sulfate, or bismuth subcarbonate, or bismuth trioxide, or bismuth oxychloride in the material of the stent body is conducive to positioning when the stent is placed, and is also conducive to later observation. Preferably, the material of the first structure comprises a developer, which is conducive to observing the morphological changes of the first structure, so as to judge the discharge condition of the stent.

[0041] In a second aspect, the embodiments of the present application provide a preparation method of a biliary stent, comprising the following steps: in a first stage, a stent body is prepared, the stent body sequentially comprises a first structure 11 and a second structure 12 from one end to the other end, the second structure 12 comprises a channel body 121 which maintains a space spiral in a natural state, and the channel body 121 comprises a guide cavity; wherein the first structure 11 comprises a first support ring 111 and a plurality of first support wires 112, the first support ring 111 and the plurality of first support wires 112 are prepared by using a 3D printing device, one end of the plurality of first support wires 112 is connected with the first support ring 111, the other end of the plurality of first support wires 112 is connected with the second structure 12, the diameter of the first support ring 111 is greater than or equal to one half of the diameter of the channel body 121 close to the first structure 11, and less than the diameter of the channel body 121 close to the first structure 11, the plurality of first support wires 112 are in a straight line type, and the average diameter of the first structure 11 is less than the average diameter of the channel body 121.

[0042] In a second stage, after the plurality of first support wires 112 are cooled and solidified, an external force mechanism is used to make the plurality of first support wires 112 raised to the outside of the stent body, and the maximum diameter of the first structure 11 is greater than the minimum diameter of the channel body 121.

[0043] In the third stage, the fixed structure 2 is prepared, one end of the fixed structure 2 is connected to the first support ring 111 and / or the plurality of first support wires 112, and the other end is connected to the stent body, so that the plurality of first support wires 112 protrude outwardly to the outer side of the stent body.

[0044] In this embodiment, first, the first structure 11 and the second structure 12 of the stent body are prepared, and the first support ring 111 and the plurality of first support wires 112 in a straight line type are prepared by using a 3D printing device; in the second stage, after the first support wires 112 in a straight line type are solidified, they are bent outwardly under an external force, specifically, the first structure 11 and the second structure 12 of the stent body can be fixed at a certain position, and then the first support ring 111 is moved towards the direction from the first structure 11 to the second structure 12, at this time, the first support wires 112 in a straight line type will protrude outwardly due to the mechanical properties of the material itself; in the third stage, the fixed structure 2 is prepared, which can make the plurality of first support wires protrude outwardly to the outer side of the stent body. If the fixed structure 2 is a degradable material, the degradation rate of the fixed structure 2 is greater than the degradation rate of the stent body, so after being sent into the biliary tract, the fixed structure 2 loses the fixing function first, and the protruding first support wires 112 will naturally return to the initial straight state, and because the diameter of the first support ring 111 is greater than or equal to one half of the diameter of the channel body 121 close to the first structure 11, and less than the diameter of the channel body 121 close to the first structure 11, the diameter of the first structure 11 becomes smaller than the diameter of the channel body 121, which is beneficial to the self-discharge of the stent out of the biliary tract; the diameter of the first support ring 111 also cannot be too small, otherwise it may affect the normal flow of bile. Optionally, the fixed structure 2 is prepared by using a hot melting process to bond the first support ring 111 and / or the plurality of first support wires 112 and the stent body by using a degradable material, or by using a degradable wire to connect the first support ring 111 and / or the plurality of first support wires 112 and the stent body.

[0045] In this embodiment, because the first structure 11 and the second structure 12 have been prepared in the first stage, one end of the fixed structure 2 can be connected to the first support ring 111, or the end of the first support wire 112 close to the first support ring 111, or the first support ring 111 and the end of the first support wire 112 close to the first support ring 111, and the other end can be connected to the end of the first support wire 112 away from the first support ring 111, or the second structure 12, so that the plurality of first support wires 112 protrude outwardly to the outer side of the stent body, and the specific way is to use a hot melting process to bond by using a degradable material or to use a degradable wire to connect.

[0046] Optionally, in the preparation of the second structure 12, the pull wire 12111 is first fixed with the first structure 11, and then the degradable support layer 12112 is semi-wrapped or fully wrapped around the pull wire 12111 by 3D printing.

[0047] The preparation method of the biliary stent in the embodiment is the same as the structure of the biliary stent described in the first aspect, and therefore the details not described in the embodiment are described in detail in the first aspect and Figures 1 to 8 The detailed description of the first aspect.

[0048] In a third aspect, the embodiment of the present application provides a preparation method of a biliary stent, and the steps are as follows: In a first stage, a stent body is prepared, which comprises a first structure 11 and a second structure 12 from one end to the other end, and the first structure 11 and the second structure 12 are prepared separately, and the second structure 12 comprises a channel body 121 that maintains a space spiral in a natural state, and the channel body 121 comprises a guide cavity; wherein the first structure comprises a first support ring 111 and a plurality of first support wires 112, the first support ring 111 and the plurality of first support wires 112 are prepared by using a 3D printing device, one end of the plurality of first support wires 112 is connected with the first support ring 111, the diameter of the first support ring 111 is greater than or equal to one half of the diameter of one end of the channel body 121 close to the first structure 11 and less than the diameter of one end of the channel body 121 close to the first structure 11, the plurality of first support wires 112 are in a straight line type, and the average diameter of the first structure 11 is less than the average diameter of the channel body 121.

[0049] In a second stage, after the plurality of first support wires 112 are cooled and solidified, an external force mechanism is used to make the plurality of first support wires 112 protrude outwardly from the stent body, and the maximum diameter of the first structure 11 is greater than the minimum diameter of the channel body 121; in a third stage, a fixing structure 2 is prepared, one end of the fixing structure 2 is connected with the first support ring 111 and / or one side of the plurality of first support wires 112 close to the first support ring 111, the other end of the fixing structure 2 is connected with one side of the plurality of first support wires 112 away from the first support ring 111, so that the plurality of first support wires 112 remain protruding outwardly from the stent body; in a fourth stage, the other end of the plurality of first support wires 112 is connected with the second structure 12.

[0050] In the embodiment, the difference from the above-mentioned embodiments is that the first structure 11 and the second structure 12 can be manufactured separately, and after the first support wires 112 in the first structure 11 are made to protrude outwardly from the stent body by the fixing structure 2, the first structure 11 and the second structure 12 are then connected, which has the advantages of higher efficiency and avoids the influence on the second structure 12 in the second stage or the third stage.

[0051] The structure of the biliary tract stent in the preparation method of the biliary tract stent described in this embodiment is the same as that of the biliary tract stent described in the first aspect, and therefore, details not covered in this embodiment are described in detail in the first aspect and Figures 1 to 8 the specific description of the first aspect, which will not be repeated here.

[0052] In a fourth aspect, the present embodiment provides a preparation method of a biliary tract stent, comprising the following steps: In the first stage, a first structure 11 of the stent body is prepared; the first structure 11 comprises a first support ring 111 and a plurality of first support wires 112, the first support ring 111 and the plurality of first support wires 112 are prepared by using a 3D printing device, one end of the plurality of first support wires 112 is connected to the first support ring 111, and the plurality of first support wires 112 are in a straight line type.

[0053] In the second stage, after the plurality of first support wires 112 are cooled and solidified, an external force mechanism is used to make the plurality of first support wires 112 bulge outwardly of the stent body.

[0054] In the third stage, a fixing structure 2 is prepared, one end of the fixing structure 2 is connected to the first support ring and / or the side of the plurality of first support wires 112 close to the first support ring 111, the other end of the fixing structure 2 is connected to the side of the plurality of first support wires 112 away from the first support ring 111, so that the plurality of first support wires 112 remain bulging outwardly of the stent body.

[0055] In the fourth stage, a second structure 12 of the stent body is prepared along the end of the plurality of first support wires 112 away from the first support ring 111, and the second structure 12 comprises a channel body 121 which maintains a space spiral in a natural state, the diameter of the first support ring 111 is greater than or equal to one half of the diameter of the end of the channel body 121 close to the first structure 11, and less than the diameter of the end of the channel body 121 close to the first structure 11.

[0056] In this embodiment, the difference from the above-mentioned embodiments is that the first structure 11 is first printed, then the first support wires 112 in the first structure 11 are kept bulging outwardly of the stent body by the fixing structure 2, and then the other end of the first support wires 112 is followed by the preparation of the second structure 12, which also avoids the influence on the second structure 12 in the second stage or the third stage.

[0057] The structure of the biliary tract stent in the preparation method of the biliary tract stent described in this embodiment is the same as that of the biliary tract stent described in the first aspect, and therefore, details not covered in this embodiment are described in detail in the first aspect and Figures 1 to 8 Figures 1 to 8 the specific description of the first aspect, which will not be repeated here.

[0058] Those skilled in the art can understand that the steps, measures, and schemes in various operations, methods, and processes discussed in the present application can be alternated, changed, combined, or deleted. Further, other steps, measures, and schemes in various operations, methods, and processes discussed in the present application can also be alternated, changed, rearranged, decomposed, combined, or deleted. Further, steps, measures, and schemes in various operations, methods, and processes in the prior art can also be alternated, changed, rearranged, decomposed, combined, or deleted.

[0059] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0060] The terms "first", "second", are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0061] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0062] In the description of the present application, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0063] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A biliary stent, characterized in that, include: The stent body includes 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 a guide wire to pass through and for fluid to flow through. The stent body includes a biodegradable material. The first structure includes a first support ring and multiple first support wires. One end of the multiple first support wires is connected to the first support ring, and the other end 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 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 fixed structure, one end of which is connected to the first support ring and / or the plurality of first support wires, and the other end of which is connected to the support body, such that the plurality of first support wires protrude outward from the support 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 become straight, and the average diameter of the first structure is smaller than the average diameter of the channel body.

2. The biliary stent according to claim 1, characterized in that, 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.

3. The biliary stent according to claim 2, characterized in that, 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.

4. The biliary stent according to claim 3, characterized in that, The outer side of the support layer includes a hydrogel layer.

5. The biliary stent according to claim 4, characterized in that, The hydrogel layer includes at least one of the following: styracin, paclitaxel, rapamycin, dexamethasone, doxycycline, and iodine-125 particles.

6. The biliary stent according to claim 1, characterized in that, 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.

7. The biliary stent according to claim 6, characterized in that, The pitch of the second structure gradually increases in the direction from the first structure to the second structure.

8. The biliary stent according to claim 6, characterized in that, The diameter of the main body of the channel gradually increases from the end closer to the first structure to the end farther away from the first structure.

9. The biliary stent according to claim 1, characterized in that, 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.

10. The biliary stent according to claim 1, characterized in that, The fixing structure includes adhesive or binding wire.

11. The biliary stent according to claim 1, characterized in that, The material of the stent body includes barium sulfate, or basic bismuth carbonate, or bismuth trioxide, or bismuth oxychloride.

12. A method for preparing a biliary stent, characterized in that, The steps are as follows: In the first stage, the stent body is prepared. The stent body includes 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. The first structure includes a first support ring and multiple first support wires. The first support ring and the multiple first support wires are prepared using 3D printing equipment. One end of the multiple first support wires is connected to the first support ring, and the other end 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 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. The multiple first support wires are straight. The average diameter of the first structure is less than the average diameter of the second structure. In the second stage, after the multiple first support wires have cooled and solidified, an external force mechanism is used to make the multiple first support wires bulge outward from the outside of 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 by connecting one end of the fixing structure to the first support ring and / or the plurality of first support wires, and the other end to the bracket body, so that the plurality of first support wires remain raised to the outside of the bracket body.

13. The method for preparing a biliary stent according to claim 12, characterized in that, The preparation of the fixed structure includes: The first support ring and / or the multiple first support wires, and the bracket body are bonded together using a hot-melt process with biodegradable materials. Alternatively, biodegradable wires can be used to connect the first support ring and / or the multiple first support wires and the bracket body.

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