A plastic biliary stent

Abstract

This application relates to the technical field of medical devices and discloses a plastic biliary stent, comprising a stent body, a delivery unit, and a guidewire. The stent body comprises a main tube, a first wing, and a second wing. The first wing is disposed at the distal end of the main tube, and the second wing is disposed at the proximal end of the main tube. The ends of the first and second wing adjacent to each other can be unfolded relative to the main tube. The delivery unit comprises a sheath tube and an inner tube. The inner tube moves within the sheath tube, and the distal end of the inner tube includes a cutting head. The guidewire is sequentially passed through the main tube and the inner tube. The first wing is received in the main tube via a connecting line. The distal end of the sheath tube is sheathed over the main tube and receives the second wing. The distal end of the inner tube extends into the proximal end of the main tube, and the inner tube has a limiting mechanism for abutting the main tube to limit the main tube. This application can prevent the stent from scratching tissue during delivery.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a plastic biliary stent. Background Art

[0002] Plastic biliary stents are medical devices used to treat conditions such as biliary stenosis and biliary obstruction. Existing plastic biliary stents typically include a stent body and wings attached to the body. The wings are used to embed into surrounding tissue to position the stent once it reaches its placement location. Referring to the plastic stent and stent releaser disclosed in Patent Publication No. CN216908267U, the plastic stent has a first positioning bracket and a second positioning bracket, and the stent releaser drives the plastic stent to move.

[0003] However, during the delivery of the plastic biliary stent, the unfolded side wings can easily scratch the tissues it passes through, causing tissue damage and possibly inducing inflammation and other problems. Summary of the Invention

[0004] In order to prevent the stent from scratching tissue during transportation, the present application provides a plastic biliary stent.

[0005] This application provides a plastic biliary stent, which adopts the following technical solution:

[0006] A plastic biliary stent, comprising a stent body, a delivery unit and a guide wire;

[0007] The stent body includes a main tube, a first side wing and a second side wing; the first side wing is arranged at the distal end of the main tube, the second side wing is arranged at the proximal end of the main tube, and the ends of the first side wing and the second side wing close to each other can be unfolded relative to the main tube;

[0008] The delivery unit includes a sheath tube and an inner tube; the inner tube moves in the sheath tube, and the distal end of the inner tube includes a cutting head;

[0009] The guide wire is sequentially passed through the main tube and the inner tube;

[0010] The first wing is received in the main tube via a connecting line, the distal end of the sheath is sleeved on the main tube and receives the second wing, the distal end of the inner tube extends into the proximal end of the main tube, and the inner tube is provided with a limiting mechanism for abutting against the main tube to limit the main tube;

[0011] When the limiting mechanism releases the clamping of the main tube, the main tube and the sheath tube can be relatively limited by the abutment of the second side wing, and at the same time the inner tube can be moved relative to the main tube to cut the connecting line, so that the first side wing is unfolded; when the limiting mechanism limits the inner tube, the sheath tube can be moved relative to the main tube to leave the second side wing, so that the second side wing is unfolded.

[0012] By adopting the above technical solution, through the cooperation of the inner tube and the sheath tube, the first side wing and the second side wing of the stent body can be unfolded in sequence after reaching the placement position, and embedded in the surrounding tissue for positioning, thereby reducing scratches and damage to the tissue.

[0013] Optionally, a plurality of connecting lines are arranged at intervals along the length direction of the main tube, and the length of each connecting line increases successively as it approaches the distal end of the main tube, so that when the cutting head cuts the connecting lines one by one toward the distal end of the main tube, the first side wing gradually unfolds.

[0014] By adopting the above technical solution, the multiple connecting wires and their gradually increasing lengths enable the first wing to gradually deploy as the cutting head cuts the connecting wires one by one. This gradual deployment reduces sudden irritation and damage to surrounding tissue during deployment, improving the smoothness and safety of stent deployment.

[0015] Optionally, the conveying unit further includes an end tube and an adjustment seat; the end tube is connected to the proximal end of the sheath tube, and the adjustment seat moves on the end tube and is connected to the inner tube to drive the inner tube to move in the sheath tube.

[0016] By adopting the above technical solution, the movement of the adjustment seat drives the movement of the inner tube, further improving the controllability of the stent delivery and release.

[0017] Optionally, the adjustment seat is sleeved on the end tube and has a connecting portion extending into the end tube, the connecting portion is connected to the inner tube, and a guide groove and a step groove for movement of the connecting portion are opened on the end tube, the guide groove extends parallel to the axial direction of the sheath tube, the step groove is connected to an end of the guide groove close to the main tube, and the step groove extends along the circumference of the end tube toward the step close to the distal end of the sheath tube;

[0018] When the connecting portion is located at one end of the guide groove away from the stepped groove, the cutting head is separated from the connecting wire, and the connecting portion cuts one connecting wire each time it moves one step in the stepped groove toward the distal end of the sheath tube.

[0019] By adopting the above technical solution, the connecting part of the adjustment seat cooperates with the guide groove and the stepped groove of the end tube, so that the connecting part can more accurately control the position of the cutting head when moving, thereby realizing successive cutting of the connecting line.

[0020] Optionally, when the connecting portion abuts against an end of the guide groove away from the stepped groove, the distal end of the sheath tube extends beyond the distal end of the inner tube.

[0021] By adopting the above technical solution, the distal end of the sheath tube extends beyond the distal end of the inner tube, so that the distal end of the inner tube can be accommodated in the sheath tube, thereby protecting the cutting head when the inner tube is separated from the main tube and preventing the cutting head from damaging tissues in the human body.

[0022] Optionally, the adjustment seat is provided with a clamping piece that moves radially along the end tube, and the outer wall of the end tube is provided with a clamping groove for the clamping piece to be inserted into. When the connecting part abuts against the end of the guide groove away from the stepped groove, the clamping piece is opposite to the clamping groove.

[0023] By adopting the above technical solution, the clamping piece cooperates with the clamping groove of the end tube, so that when the connecting part abuts against the end of the guide groove away from the stepped groove, the adjustment seat can be limited to prevent it from accidentally moving during transportation.

[0024] Optionally, the distal end of the inner tube includes an operating section with an outer diameter smaller than that of other parts, and the limiting mechanism includes a limiting rod, an elastic member, a pulling wire, and a shift-blocking member;

[0025] The limiting rods are provided in a plurality along the circumference of the operating section, each of the limiting rods including a first portion and a second portion provided along its length direction, the limiting rods being hinged to the outer circumference of the operating section at the junction of the first portion and the second portion, and the first portion being closer to the distal end of the main tube than the second portion;

[0026] The elastic member is connected between the outer periphery of the operating section and the limiting rod, and is used to give the first part an elastic force to rotate toward the operating section;

[0027] One end of the pulling wire is connected to the second part, and the other end slides through the inner tube and extends out from the proximal end of the inner tube;

[0028] The blocking member is connected to the pull wire, and is used to limit the pull wire from sliding toward the distal end of the inner tube; the blocking member can adjust the limit rod to a first state, a second state, and a third state; when the limit rod is in the first state, the distance between the limit rod and the outer wall of the operating section gradually decreases along the proximal end of the inner tube; when the limit rod is in the second state, the distance between the limit rod and the outer wall of the operating section is consistent along the axial direction of the inner tube; when the limit rod is in the third state, the distance between the limit rod and the outer wall of the operating section gradually increases along the proximal end of the inner tube;

[0029] The inner circumference of the main body tube has an annular groove formed along its own circumference. When the operating section is opposite to the annular groove, the first part of the limiting rod in the first state enters the annular groove, the second part of the limiting rod in the third state enters the annular groove, and the limiting rod in the second state leaves the annular groove.

[0030] By adopting the above technical solution, the limit rod can prevent the main tube from moving away from the proximal end of the inner tube in the first state, and the limit rod can prevent the main tube from moving close to the proximal end of the inner tube in the third state, so as to meet the limiting requirements for the main tube under different operations.

[0031] Optionally, the anti-displacement member includes a locking seat and an anti-displacement sleeve; the locking seat slides along the axis of the inner tube at the proximal end of the inner tube and is connected to the pulling line, the anti-displacement sleeve is threadedly sleeved on the part of the locking seat extending out of the inner tube, and the anti-displacement sleeve is opposite to the end of the inner tube.

[0032] By adopting the above technical solution, the displacement-blocking sleeve abuts against the end of the inner tube to restrict the pulling wire from driving the locking seat to move into the inner tube, thereby limiting the pulling wire.

[0033] Optionally, an abutment edge is formed on the inner periphery of the distal end of the sheath tube for abutting against the proximal end of the main body tube.

[0034] By adopting the above technical solution, the abutment edge on the inner circumference of the distal end of the sheath tube enables the proximal end of the main tube to abut against it, so that the relative position between the main tube and the sheath tube is stable during the stent delivery process.

[0035] In summary, this application has at least one of the following beneficial effects:

[0036] 1. Through the coordination of the stent body, delivery unit, and guidewire, the plastic biliary stent can stably reach the target position during delivery. The first and second wings can gradually unfold in a predetermined sequence and embed into the surrounding tissue for positioning, preventing the first and second wings from scratching the surrounding tissue during delivery.

[0037] 2. The cutting head gradually cuts the multiple connecting lines and the sheath gradually releases the second wing, so that the first wing and the second wing can be gradually unfolded, which is not likely to cause sudden stimulation to the surrounding tissues. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 1 is a front view of a plastic biliary stent according to an embodiment of the present application;

[0039] Figure 2 1 is a top view of a plastic biliary stent according to an embodiment of the present application;

[0040] Figure 3 yes Figure 2 Cross-section at AA in the middle;

[0041] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure at B in the middle;

[0042] Figure 5 yes Figure 3 Schematic diagram of the enlarged structure at C in the middle;

[0043] Figure 6 yes Figure 1 Schematic diagram of the enlarged structure at D in the middle;

[0044] Figure 7 This is a structural diagram of the adjustment seat and the connecting portion in an embodiment of the present application;

[0045] Figure 8 yes Figure 3 Schematic diagram of the enlarged structure at E in the middle;

[0046] Figure 9 yes Figure 3 Schematic diagram of the enlarged structure at F in the middle.

[0047] Explanation of the accompanying drawings: 1. Guide wire; 2. Main body tube; 3. First side wing; 4. Second side wing; 5. Sheath; 51. Sleeve section; 52. Delivery section; 6. Inner tube; 61. Cutting head; 62. Operating section; 63. Moving section; 7. Connecting line; 8. End tube; 9. Adjusting seat; 10. Connecting part; 11. Guide groove; 12. Step groove; 13. Snap-fit ​​part; 14. Snap-fit ​​groove; 15. Limiting rod; 151. First part; 152. Second part; 16. Elastic part; 17. Pull line; 18. Blocking part; 181. Locking seat; 182. Blocking sleeve; 19. Annular groove; 20. Abutting edge; 21. Cutting knife; 22. First end face; 23. Second end face. DETAILED DESCRIPTION

[0048] The following is combined with Figure 1 To the attached Figure 9This application is described in further detail.

[0049] The present application embodiment discloses a plastic biliary stent. Figure 1 The plastic biliary stent comprises a stent body, a delivery unit, and a guidewire 1. The stent body is mounted on the delivery unit, and the guidewire 1 slides through the stent body and the delivery unit. In this embodiment, the end of each component closest to the operator is referred to as the proximal end, and the end away from the operator is referred to as the distal end.

[0050] Reference Figure 2 and Figure 3 , wherein the stent body includes a main tube 2, a first side wing 3 and a second side wing 4. The main tube 2 is in the shape of a circular tube, the first side wing 3 is connected to the distal end of the main tube 2, and the end of the first side wing 3 close to the proximal end of the main tube 2 has a tendency to expand outward. The second side wing 4 is connected to the proximal end of the main tube 2, and the end of the second side wing 4 close to the distal end of the main tube 2 has a tendency to expand outward. When the main tube 2 is in the initial state, the first side wing 3 and the main tube 2 are connected by a connecting line 7 through degradable glue. The connecting line 7 accommodates the first side wing 3 in the wall of the main tube 2 to limit the expansion of the first side wing 3, and the connecting line 7 is an absorbable line that can gradually decompose in the human body; at the same time, the second side wing 4 is also accommodated in the wall of the main tube 2 due to the restriction of the conveying unit and is restricted from expansion.

[0051] Reference Figure 3 and Figure 4 The delivery unit includes a sheath tube 5 and an inner tube 6. The sheath tube 5 includes a sheath section 51 and a delivery section 52, which are distributed in sequence along its own axial direction toward its own proximal end. The outer diameter of the proximal end of the sheath section 51 is consistent with the outer diameter of the delivery section 52, and the outer diameter of the distal end of the sheath section 51 gradually decreases to have a guiding effect. The sheath section 51 is used to sheath the main tube 2, and the delivery section 52 is used to sheath the inner tube 6. The inner diameter of the sheath section 51 is larger than the inner diameter of the delivery section 52, so that the junction of the sheath section 51 and the delivery section 52 forms an abutment edge 20 toward the distal end of the sheath section 51, and the abutment edge 20 is used for abutting the proximal end of the main tube 2.

[0052] The inner tube 6 comprises a cutting head 61, an operating section 62, and a movable section 63, which are arranged in sequence along its axial direction toward its proximal end. Both the operating section 62 and the movable section 63 are bendable and possess a certain degree of support strength. The main body of the cutting head 61 is cylindrical, with an outer diameter comparable to the inner diameters of the conveying section 52 and the main tube 2. The outer periphery of the end of the cutting head 61 proximal to the operating section 62 has a circumferentially extending chamfer. The end of the cutting head 61 facing away from the operating section 62 has a cutting blade 21 with a blade facing away from the operating section 62. The operating section 62 is tubular, with an outer diameter smaller than the inner diameter of the main tube 2. The movable section 63 is tubular, with an outer diameter comparable to the inner diameters of the conveying section 52 and the main tube 2. The movable section 63 is connected to the operating section 62.

[0053] When the sheath tube 5 and the inner tube 6 cooperate, the movable section 63 slides in the conveying section 52 to drive the cutting head 61 and the operating section 62 to be stored in the sleeve section 51 or move out from the distal end of the sleeve section 51, and the proximal end of the movable section 63 extends out of the proximal end of the conveying section 52.

[0054] When the main tube 2 is fitted onto the sheath tube 5 and inner tube 6, the distal ends of the cutting head 61, operating section 62, and movable section 63 enter the main tube 2, with the cutting blade 21 facing the connecting line 7. Simultaneously, the sheathing section 51 is sheathed onto the main tube 2, causing the main tube 2 to abut against the abutment edge 20. This forces the second wing 4 to be pressed into the wall of the main tube 2 by the sheathing section 51, and the outward expansion of the second wing 4 causes it to abut against the inner wall of the sheathing section 51. Simultaneously, the guidewire 1 extends from the distal end of the main tube 2, sequentially passing through the cutting head 61, operating section 62, and the middle of the movable section 63, extending out of the operating section 62 to guide the movement of the biliary stent.

[0055] Reference Figure 3 and Figure 4 What's more, the inner tube 6 has a limiting mechanism for limiting the main tube 2. The limiting mechanism of the inner tube 6 and the sleeve section 51 limit the main tube 2, so that the sheath tube 5 can drive the stent to move in the human body without being easily displaced.

[0056] When the main tube 2 moves into the bile duct and reaches the placement position, the inner tube 6 is first released from its positional restraint on the main tube 2. The inner tube 6 is then moved within the main tube 2 toward the distal end of the main tube 2, causing the cutting head 61 to cut the connecting line 7, thereby deploying the first wing 3. The inner tube 6 is then readjusted to its positional restraint on the main tube 2, and the sheath tube 5 is then pulled proximally, causing the sheathing section 51 to gradually and slowly release the second wing 4. After the second wing 4 is released, the distal end of the sheathing section 51 still sheathes the proximal end of the main tube 2. The inner tube 6 is then released from its positional restraint on the main tube 2, allowing the inner tube 6 to move until it is received by the cutting head 61 within the sheath tube 5. The sheath tube 5 is then moved proximally away from the main tube 2.

[0057] Reference Figure 2 and Figure 4 Among them, for the cooperation between the cutting head 61 and the connecting wire 7, multiple connecting wires 7 are arranged at intervals along the length direction of the main tube 2, and the conveying unit also includes an end tube 8 that cooperates with the sheath tube 5 and an adjustment seat 9 that cooperates with the inner tube 6. The cutting head 61 is driven by the movement of the adjustment seat 9 on the end tube 8 to cut off the multiple connecting wires 7 in sequence.

[0058] Reference Figure 4 and Figure 5Specifically, there are three connecting lines 7 spaced apart and located at different points along the length of the first wing 3. The lengths of the three connecting lines 7 increase sequentially as they move away from the proximal end of the main tube 2. When the first wing 3 is housed in the wall of the main tube 2, the connecting line 7 closest to the proximal end of the main tube 2 is stretched, while the remaining connecting lines 7 are relaxed. When the first connecting line 7 closest to the proximal end of the main tube 2 is severed, the first wing 3 expands outward for a distance and straightens the second connecting line 7 closest to the proximal end of the main tube 2. Similarly, when the second connecting line 7 is severed, the first wing 3 continues to expand outward for a distance until the last connecting line 7 is severed, fully expanding the first wing 3. This achieves multi-stage expansion of the first wing 3, reducing the impact of inertia on human tissue when the first wing 3 is expanded. The figure only briefly illustrates the connecting lines 7, and does not show their relaxed state. It should be noted that the connecting lines 7 are eccentrically arranged to make way for the guide wire 1.

[0059] Reference Figure 6 and Figure 7 The end tube 8 is fixedly connected to the proximal end of the sheath tube 5 and is cylindrical and coaxial with the sheath tube 5. The movable section 63 of the inner tube 6 slides out of the end tube 8. The adjustment seat 9 is annular and is sleeved on the outer wall of the end tube 8. The inner wall of the adjustment seat 9 has a connecting portion 10 extending radially from the end tube 8 to the end tube 8 and connected to the inner tube 6. The wall of the end tube 8 is provided with a guide groove 11 and a stepped groove 12 for the sliding movement of the connecting portion 10. The guide groove 11 extends axially parallel to the end tube 8. The stepped groove 12 is connected to the end of the guide groove 11 close to the sheath tube 5. The stepped groove 12 extends in a stepped manner away from the guide groove 11 and along the circumference of the end tube 8. The stepped groove 12 has multiple steps. Each step includes a transverse groove extending circumferentially along the end tube 8 and a longitudinal groove connected to the end of the transverse groove and extending axially parallel to the end tube 8. The extension length of the longitudinal groove is equivalent to the distance between the two adjacent connecting lines 7.

[0060] Reference Figure 4 、 Figure 5 and Figure 6When the connecting portion 10 is located at the end of the guide groove 11 away from the sheath tube 5, the cutting head 61 is located in the proximal end of the main tube 2 and has a distance from the connecting wire 7, and the distal end of the sheath tube 5 extends beyond the distal end of the inner tube 6. When the adjusting seat 9 drives the connecting portion 10 to move into the first transverse groove of the stepped groove 12, the cutting knife 21 contacts the first connecting wire 7, and then the adjusting seat 9 is rotated relative to the end tube 8 so that the connecting portion 10 is opposite to the first longitudinal groove of the stepped groove 12, so that the cutting knife 21 and the connecting wire 7 move relative to each other, so that the cutting knife 21 cuts the connecting wire 7, and then the adjusting seat 9 continues to drive the connecting portion 10 through the longitudinal groove into the second transverse groove of the stepped groove 12, so that the cutting knife 21 contacts the second connecting wire 7, and so on. In the process of the connecting portion 10 gradually moving closer to the sheath tube 5 in the stepped groove 12, one connecting wire 7 is cut off each time it moves a step, thereby realizing the sequential cutting of the connecting wires 7.

[0061] Reference Figure 4 and Figure 8 As for the limiting mechanism, the limiting mechanism includes a limiting rod 15, an elastic member 16, a pulling line 17 and a blocking member 18. A plurality of limiting rods 15 are evenly spaced along the circumference of the operating section 62, and the limiting rod 15 is hinged to the outer periphery of the operating section 62 through the cooperation of the hinge shaft and the hinge seat. Specifically, the limiting rod 15 includes a first part 151 and a second part 152 sequentially arranged along its own length direction. The extension length of the first part 151 is consistent with the extension length of the second part 152, and the limiting rod 15 is hinged to the operating section 62 through the intersection of the first part 151 and the second part 152. The first part 151 is closer to the cutting head 61 than the second part 152, and the rotation axis of the limiting rod 15 is parallel to the radial line of the operating section 62. In this embodiment, there are two limiting rods 15.

[0062] Elastic members 16 correspond one-to-one with the limiting rods 15. They are connected between the first portion 151 of the corresponding limiting rod 15 and the outer periphery of the operating section 62, imparting an elastic force to the first portion 151 to rotate toward the operating section 62. In this embodiment, elastic member 16 is preferably a spring. Pull wires 17 correspond one-to-one with the limiting rods 15. One end of each pull wire 17 is connected to the second portion 152 of the corresponding limiting rod 15. The other end of each pull wire 17 slides through the inner cavity of the operating section 62 and extends from the end of the movable section 63 away from the operating section 62.

[0063] The blocking member 18 is used to adjust the state of the pull line 17, and includes a locking seat 181 and an blocking sleeve 182. The locking seat 181 is fixedly connected to all the pull lines 17 at the same time. At the same time, the locking seat 181 slides in the proximal end of the moving section 63, and the locking seat 181 extends from the end of the moving section 63 away from the operating section 62. The blocking sleeve 182 is threadedly sleeved on the part of the locking seat 181 extending from the moving section 63. The outer diameter of the blocking sleeve 182 is larger than the outer diameter of the moving section 63, and the blocking sleeve 182 is threadedly moved relative to the locking seat 181 toward or away from the moving section 63.

[0064] The elastic member 16 pulls the first portion 151, causing the second portion 152 to rotate away from the operating section 62. This causes the pull wire 17 and the locking seat 181, pulled by the second portion 152, to move toward the operating section 62. When the displacement-blocking sleeve 182 is threadedly moved to abut the proximal end of the moving section 63, it prevents the locking seat 181 from moving into the moving section 63. Thus, the rotational state of the limit rod 15 can be adjusted by adjusting the elastic member 16 and the position of the displacement-blocking sleeve 182.

[0065] Reference Figure 4 and Figure 8 Specifically, the elastic member 16 and the displacement-blocking sleeve 182 are capable of rotating the limiting rod 15 between first, second, and third relative positions. An annular groove 19 is coaxially defined on the inner circumference of the main tube 2 for engaging with the limiting rod 15. The annular groove 19 is located between the first wing 3 and the second wing 4. The inner end surface of the annular groove 19 near the distal end of the main tube 2 is a first end surface 22, while the inner end surface of the annular groove 19 away from the distal end of the main tube 2 is a second end surface 23. The limiting rod 15 adjusts its position when the operating section 62 is aligned with the annular groove 19. When the limiting rod 15 is in the first position, the elastic member 16 pulls the limiting rod 15 so that the first portion 151 approaches the operating section 62 and the second portion 152 moves away from the operating section 62. At this time, the end of the second portion 152 away from the first portion 151 enters the annular groove 19 and is aligned with and aligned with the second end surface 23. When the limiting rod 15 is in the second state, the limiting rod 15 is pulled by the elastic member 16 and the pull line 17 to maintain a state parallel to the operating section 62. At this time, the limiting rod 15 leaves the annular groove 19. When the limiting rod 15 is in the third state, the limiting rod 15 is pulled by the elastic member 16 and the pull line 17, so that the first portion 151 moves away from the operating section 62 and the second portion 152 moves closer to the operating section 62. At this time, the end of the first portion 151 away from the second portion 152 enters the annular groove 19 and is opposite to and close to the first end surface 22.

[0066] Reference Figure 4 、 Figure 5 and Figure 6The specific scenario for adjusting the state of the limit rod 15 is as follows: when the sheath tube 5 and the inner tube 6 jointly limit the main tube 2 to drive the main tube 2 to move, the connecting portion 10 is located at the end of the guide groove 11 away from the stepped groove 12. At this time, the operating section 62 is opposite to the annular groove 19 and the limit rod 15 is in the first state, so that when the main tube 2 moves relative to the sheath tube 5 toward the proximal end of the sheath tube 5, it is blocked and limited by the abutment edge 20. When the main tube 2 moves relative to the sheath tube 5 toward the proximal end of the sheath tube 5, the second end face 23 can abut against the end of the second portion 152 to limit the movement of the main tube 2, thereby limiting the main tube 2 from leaving the conveying unit through the abutment edge 20 and the second portion 152.

[0067] When the main tube 2 reaches the position where the cutting head 61 is required to cut the connecting line 7 , the limiting rod 15 is adjusted to the second state so that the limiting rod 15 can move in the main tube 2 together with the inner tube 6 .

[0068] After the first wing 3 is deployed, the inner tube 6 is moved back to the position where the operating section 62 is opposite to the annular groove 19, and the limiting rod 15 is adjusted to the third state. Then, the sheath tube 5 is pulled away from the distal end of the main tube 2 to release the second wing 4. During this process, the main tube 2 is limited by the first part 151, so that the deployed first wing 3 is not easy to excessively squeeze the surrounding tissue.

[0069] After the second side wing 4 is also unfolded, the limit rod 15 is adjusted to the second state, and the inner tube 6 is moved relative to the sheath tube 5 until the connecting portion 10 abuts against the end of the guide groove 11 away from the stepped groove 12, so that the inner tube 6 is recovered in the sheath tube 5, and then the sheath tube 5 is slid away from the main tube 2 and leaves the human body.

[0070] Reference Figure 2 and Figure 9 Furthermore, to enhance the stability of the inner tube 6 and sheath tube 5 during delivery of the stent body and when removed from the human body, a clamping member 13 is provided on the adjustment base 9, extending radially along the end tube 8. A clamping groove 14 is defined on the outer wall of the end tube 8 for insertion of the clamping member 13. When the connecting portion 10 abuts the end of the guide groove 11 away from the stepped groove 12, the clamping member 13 can be inserted into the clamping groove 14, thereby restricting relative movement between the sheath tube 5 and the inner tube 6. The clamping member 13 can be a spring latch or a bolt, but in this embodiment, a spring latch is preferred.

[0071] The implementation principle of a plastic biliary stent according to an embodiment of the present application is as follows: during delivery of the stent body, the main tube 2 is restrained by the second portion 152 of the restraining rod 15 and the sheath 5. When the main tube 2 reaches the placement position, the restraining rod 15 releases the restraint on the main tube 2, and the inner tube 6 moves to the cutting head 61, which cuts the connecting line 7, gradually deploying the first wing 3. The inner tube 6 is then adjusted and moved until it is restrained by the first portion 151, and the sheath 5 is then moved to gradually release the second wing 4. Finally, the inner tube 6 is moved until it is stored in the sheath 5 and removed from the human body.

[0072] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A plastic biliary stent, characterized by: It comprises a stent body, a delivery unit and a guide wire (1); The stent body comprises a main body tube (2), a first side wing (3) and a second side wing (4); the first side wing (3) is arranged at the distal end of the main body tube (2), the second side wing (4) is arranged at the proximal end of the main body tube (2), and the ends of the first side wing (3) and the second side wing (4) close to each other can be unfolded relative to the main body tube (2); The transport unit comprises a sheath tube (5) and an inner tube (6); the inner tube (6) moves in the sheath tube (5), and the distal end of the inner tube (6) comprises a cutting head (61); The guide wire (1) is sequentially passed through the main tube (2) and the inner tube (6); The first wing (3) is received in the main tube (2) via a connecting line (7); the distal end of the sheath tube (5) is sleeved on the main tube (2) and receives the second wing (4); the distal end of the inner tube (6) extends into the proximal end of the main tube (2); and the inner tube (6) is provided with a limiting mechanism for abutting against the main tube (2) to limit the position of the main tube (2); When the limiting mechanism releases the clamping of the main tube (2), the main tube (2) and the sheath tube (5) can be relatively limited by the contact of the second side wing (4), and at the same time, the inner tube (6) can be moved relative to the main tube (2) to cut off the connecting line (7), so that the first side wing (3) is unfolded; when the limiting mechanism limits the inner tube (6), the sheath tube (5) can be moved relative to the main tube (2) to leave the second side wing (4), so that the second side wing (4) is unfolded.

2. The plastic biliary stent according to claim 1, characterized in that: A plurality of connecting lines (7) are arranged at intervals along the length direction of the main body tube (2), and the length of each connecting line (7) increases successively as it approaches the distal end of the main body tube (2), so that when the cutting head (61) successively cuts the connecting lines (7) toward the distal end of the main body tube (2), the first side wing (3) gradually unfolds.

3. The plastic biliary stent according to claim 2, characterized in that: The conveying unit further comprises an end tube (8) and an adjusting seat (9); the end tube (8) is connected to the proximal end of the sheath tube (5), and the adjusting seat (9) moves on the end tube (8) and is connected to the inner tube (6) to drive the inner tube (6) to move in the sheath tube (5).

4. The plastic biliary stent according to claim 3, characterized in that: The adjustment seat (9) is sleeved on the end tube (8) and has a connecting portion (10) extending into the end tube (8), the connecting portion (10) is connected to the inner tube (6), and the end tube (8) is provided with a guide groove (11) and a stepped groove (12) for the connecting portion (10) to move, the guide groove (11) extending in parallel with the axial direction of the sheath tube (5), the stepped groove (12) is connected to an end of the guide groove (11) close to the main tube (2), and the stepped groove (12) extends along the circumference of the end tube (8) toward the distal end of the sheath tube (5); When the connecting portion (10) is located at one end of the guide groove (11) away from the stepped groove (12), the cutting head (61) is separated from the connecting wire (7), and the connecting portion (10) cuts one of the connecting wires (7) each time it moves one step in the stepped groove (12) toward the distal end of the sheath tube (5).

5. The plastic biliary stent according to claim 4, characterized in that: When the connecting portion (10) abuts against one end of the guide groove (11) away from the stepped groove (12), the distal end of the sheath tube (5) extends beyond the distal end of the inner tube (6).

6. The plastic biliary stent according to claim 4, characterized in that: The adjusting seat (9) is provided with a clamping piece (13) which moves radially along the end tube (8), and a clamping groove (14) for the clamping piece (13) to be inserted into the outer wall of the end tube (8). When the connecting portion (10) is in contact with the end of the guide groove (11) away from the stepped groove (12), the clamping piece (13) is opposite to the clamping groove (14).

7. The plastic biliary stent according to claim 1, characterized in that: The distal end of the inner tube (6) includes an operating section (62) having an outer diameter smaller than that of other parts, and the limiting mechanism includes a limiting rod (15), an elastic member (16), a pulling wire (17), and a blocking member (18); The limiting rod (15) is provided in a plurality along the circumference of the operating section (62), and the limiting rod (15) includes a first portion (151) and a second portion (152) provided along its length direction. The limiting rod (15) is hinged to the outer circumference of the operating section (62) through the intersection of the first portion (151) and the second portion (152), and the first portion (151) is closer to the distal end of the main body tube (2) than the second portion (152); The elastic member (16) is connected between the outer periphery of the operating section (62) and the limiting rod (15), and is used to give the first part (151) an elastic force to rotate toward the operating section (62); One end of the pulling wire (17) is connected to the second part (152), and the other end slides through the inner tube (6) and extends from the proximal end of the inner tube (6); The blocking member (18) is connected to the pulling wire (17) and is used to limit the pulling wire (17) from sliding toward the distal end of the inner tube (6); the blocking member (18) can adjust the limiting rod (15) to a first state, a second state, and a third state; when the limiting rod (15) is in the first state, the distance between the limiting rod (15) and the outer wall of the operating section (62) gradually decreases along the proximal end of the inner tube (6); when the limiting rod (15) is in the second state, the distance between the limiting rod (15) and the outer wall of the operating section (62) is consistent along the axial direction of the inner tube (6); when the limiting rod (15) is in the third state, the distance between the limiting rod (15) and the outer wall of the operating section (62) gradually increases along the proximal end of the inner tube (6); The inner circumference of the main body tube (2) has an annular groove (19) formed along its own circumference. When the operating section (62) is opposite to the annular groove (19), the first portion (151) of the limiting rod (15) in the first state enters the annular groove (19), the second portion (152) of the limiting rod (15) in the third state enters the annular groove (19), and the limiting rod (15) in the second state leaves the annular groove (19).

8. The plastic biliary stent according to claim 7, characterized in that: The blocking member (18) includes a locking seat (181) and a blocking sleeve (182); the locking seat (181) slides along the axis of the inner tube (6) at the proximal end of the inner tube (6) and is connected to the pulling line (17), and the blocking sleeve (182) is threadedly sleeved on the portion of the locking seat (181) extending out of the inner tube (6), and the blocking sleeve (182) is opposite to the end of the inner tube (6).

9. The plastic biliary stent according to claim 7, characterized in that: An abutment edge (20) is formed on the inner periphery of the distal end of the sheath tube (5) for abutting the proximal end of the main body tube (2).

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