阅读说明：本技术 一种胆系支架 (Biliary stent ) 是由 冯亚东 施瑞华 李媛媛 徐伟 孙亿民 沈正华 冷德嵘 于 2021-09-01 设计创作，主要内容包括：本申请公开了一种胆系支架,其包括第一管状支架和第二管状支架,所述第一管状支架具有近端开口、远端开口和延伸在所述近端开口和远端开口之间的管体,所述第二管状支架的第一端从所述远端开口插入所述第一管状支架中并被固定至所述第一管状支架,形成嵌套区段,其中所述第一管状支架的直径大于所述第二管状支架的直径,使得在所述嵌套区段中在所述第一管状支架的内壁与所述第二管状支架的外壁之间形成通路,该通路通过所述第一管状支架的所述远端开口与外部连通。根据本发明实施例的胆系支架为实现经胆囊管或肝胆管进行取碎石或引流的微创手术提供了可能。(A biliary stent includes a first tubular stent having a proximal opening, a distal opening, and a tubular body extending between the proximal opening and the distal opening, and a second tubular stent having a first end inserted into the first tubular stent from the distal opening and secured to the first tubular stent forming a nested section, wherein a diameter of the first tubular stent is greater than a diameter of the second tubular stent such that a passageway is formed in the nested section between an inner wall of the first tubular stent and an outer wall of the second tubular stent, the passageway communicating with an exterior through the distal opening of the first tubular stent. The biliary stent provided by the embodiment of the invention provides possibility for realizing minimally invasive surgery for taking gravels or draining through a cystic duct or a hepatobiliary duct.)

1. A biliary stent comprising a first tubular stent having a proximal opening, a distal opening, and a tubular body extending between the proximal opening and the distal opening, and a second tubular stent having a first end inserted into the first tubular stent from the distal opening and secured to the first tubular stent forming a nested section, wherein the first tubular stent has a diameter greater than a diameter of the second tubular stent such that a passageway is formed in the nested section between an inner wall of the first tubular stent and an outer wall of the second tubular stent, the passageway communicating with an exterior through the distal opening of the first tubular stent.

2. A biliary stent according to claim 1, wherein the first tubular stent is for placement in a common bile duct and a second end of the second tubular stent, opposite the first end, is for placement in a cystic duct or an intrahepatic bile duct.

3. A biliary stent according to claim 2, wherein the first tubular stent has a diameter of 6-12mm, preferably 8-10 mm; the diameter of the second tubular stent is 3-7mm, preferably 3-4 mm.

4. A biliary stent according to claim 1, wherein the second end of the second tubular stent is configured with an enlarged end for preventing displacement.

5. A biliary stent according to claim 4, wherein the second end of the second tubular stent forms a trumpet-shaped opening or a mushroom-shaped end.

6. A biliary stent according to claim 1, wherein the second tubular stent is fixed in the first tubular stent in conformity with a side inner wall of the first tubular stent.

7. A biliary stent according to claim 6, wherein the second tubular stent is secured to the inner wall of the first tubular stent by means of glue or suture in the nested section.

8. A biliary stent according to any one of claims 1-7, wherein the first and second tubular stents are braided from elastic wire or laser engraved, the first tubular stent is covered with a membrane, and a portion of the second tubular stent protruding from the first tubular stent is covered with a membrane.

9. The biliary stent of any one of claims 1-7, wherein the first tubular stent and the second tubular stent are formed from a degradable material.

10. The biliary stent of any one of claims 1-6, wherein the first tubular stent and the second tubular stent are integrally formed by 3D printing.

11. A biliary stent according to any one of claims 1-7, wherein the length of the nested segment is equal to or greater than 2mm, preferably equal to or greater than 1 cm.

12. A biliary stent according to claim 11, wherein a ratio of a length of the nested section to a length of the first tubular stent is equal to or less than 0.6.

13. A biliary stent according to claim 11, wherein the first tubular stent has a length of 3-8cm, preferably 4-6 cm.

14. A biliary stent according to any one of claims 11-13, wherein a length of a portion of the second tubular stent protruding from the first tubular stent is 3-12 cm.

Technical Field

The invention relates to a medical appliance, in particular to a biliary stent which can be used for taking broken stones from a gall bladder, taking broken stones from a left hepatic duct or a right hepatic duct or draining.

Background

Gallstones are diseases in the biliary tract including gallstones or gallstones in the hepatobiliary tract. Mainly comprises cholecystolithiasis, choledocholithiasis and calculus of intrahepatic duct and extrahepatic duct. The common bile duct stones and the extrahepatic bile duct stones have more clinical treatment means and mature technology, and the stones can be taken from the lower part of the laparoscope to the lower part of the endoscope; for gall bladder stones and intrahepatic bile duct stones, due to structural limitations of gall bladder ducts and intrahepatic bile ducts, treatment means are relatively limited, and clinical stone removal means are invasive operations at present.

For cholecystolithiasis, because the cholecystoscope is provided with a wrinkle structure, the choledochoscope is difficult to pass through, and therefore, the cholecystolithiasis cannot be removed under a non-invasive scope. The gallbladder is usually removed by laparoscopy, or the gallbladder is cut open under laparoscopy to remove stones, or the gallbladder stone is removed by endoscopic NOTES (natural orifice endoscopic surgery). All the operations are invasive operations and have certain risks.

Because the intrahepatic bile duct is deeper and has smaller diameter, particularly when the intrahepatic bile duct is combined with stenosis, an effective channel is not available to allow an endoscope to pass through, and lithotripsy and lithotomy are performed.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a biliary stent, which can establish a temporary channel in a cystic duct or an intrahepatic bile duct to facilitate endoscopic lithotripsy and lithotomy, and the temporary channel established by the stent of the present invention can be used for drainage.

According to one aspect of the present invention, there is provided a biliary stent including a first tubular stent having a proximal opening, a distal opening, and a tubular body extending between the proximal opening and the distal opening, and a second tubular stent having a first end inserted into the first tubular stent from the distal opening and fixed to the first tubular stent forming a nested section, wherein a diameter of the first tubular stent is larger than a diameter of the second tubular stent such that a passageway is formed between an inner wall of the first tubular stent and an outer wall of the second tubular stent in the nested section, the passageway communicating with an exterior through the distal opening of the first tubular stent.

In some embodiments, the first tubular stent is for placement in the common bile duct and the second tubular stent opposite the first end is for placement in the cystic duct or intrahepatic bile duct.

The diameter of the first tubular stent may be 6-12mm, preferably 8-10mm, and the diameter of the second tubular stent may be 3-7mm, preferably 3-4 mm.

In some embodiments for cholecystectomy, it is preferred that the second end of the second tubular stent is configured with an enlarged end for preventing displacement. The second end of the second tubular stent preferably forms a flared opening or mushroom-shaped end. In some embodiments for intrahepatic choledocholithiasis, the second end may also be free of an enlarged end.

Preferably, the second tubular stent is fixed in the first tubular stent in such a manner as to be fitted with one side inner wall of the first tubular stent.

Preferably, the second tubular stent is fixed to the inner wall of the first tubular stent by means of gluing or stitching in the nesting sections.

In some embodiments, the first and second tubular stents may be braided from elastic wire or laser-carved, preferably the first tubular stent is covered with a membrane, and the portion of the second tubular stent that protrudes from the first tubular stent is covered with a membrane.

In some embodiments, the first and second tubular stents may be formed of a degradable material.

In some embodiments, the first tubular stent and the second tubular stent may be integrally molded by 3D printing.

Preferably, the length of the nesting sections is greater than or equal to 2mm, preferably greater than or equal to 1 cm.

Preferably, the ratio of the length of the nesting section to the length of the first tubular stent is less than or equal to 0.6.

Preferably, the length of the first tubular stent is 3-8cm, preferably 4-6 cm.

Preferably, the length of the portion of the second tubular stent protruding from the first tubular stent is 3-12 cm. The length of the portion of the second tubular stent protruding from the first tubular stent may be 3-6cm when the stent is used for cholecystectomy. When the stent is used for intrahepatic duct lithotripsy, the length of the part of the second tubular stent extending from the first tubular stent may be 6-12 cm.

The biliary stent provided by the embodiment of the invention provides possibility for realizing minimally invasive surgery for taking gravels or draining through the cystic duct or intrahepatic bile duct.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings:

FIG. 1 is a schematic perspective view of a biliary stent according to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of a biliary stent according to an embodiment of the present invention;

FIG. 3 is a schematic front view of a biliary stent according to an embodiment of the present invention;

FIG. 4 schematically illustrates an application example of a biliary stent according to an embodiment of the present invention;

fig. 5 schematically illustrates another application example of a biliary stent according to an embodiment of the present invention;

FIG. 6 schematically illustrates dimensions of portions of a biliary stent, according to an embodiment of the present invention;

fig. 7 shows a stent according to a pair of scales.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings.

First, the structure of the biliary stent 10 according to an embodiment of the present invention is described with reference to fig. 1 to 3, wherein fig. 1, 2, and 3 are a schematic perspective view, a cross-sectional view, and a front view of the biliary stent 10, respectively.

As shown in fig. 1, a biliary stent 10 according to an embodiment of the present invention includes a first tubular stent 11 and a second tubular stent 12. The first tubular stent 11 has a proximal opening 11a, a distal opening 11b, and a tubular body 11c extending between the proximal opening 11a and the distal opening 11 b.

As shown more clearly in fig. 2, one end (first end) 12a of the second tubular stent 12 is inserted into the first tubular stent 11 from the distal end opening 11b and fixed to the first tubular stent 11, forming a nesting section 10 a.

According to the embodiment of the present invention, as shown in fig. 1 to 3, the diameter of the first tubular stent 11 is larger than the diameter of the second tubular stent 12, so that a passage p is formed between the inner wall of the first tubular stent 11 and the outer wall of the second tubular stent 12 in the nesting section 10a, and the passage p communicates with the outside through the distal end opening 11b of the first tubular stent 11.

Preferably, the second tubular stent 12 is fixed in the first tubular stent 11 in such a way as to conform to one side inner wall of the first tubular stent 11, as shown more clearly in fig. 1 and 2.

In some embodiments, the second tubular stent 12 may be fixed to the inner wall of the first tubular stent 11 in the nesting section 10a by means of gluing or stitching.

In some embodiments, the first tubular stent 11 and the second tubular stent 12 may be braided with elastic wires, as shown in fig. 1 and 3. Here, the elastic thread is preferably a memory alloy thread, and may be, for example, an elastic polymer thread.

In other embodiments, the first tubular stent 11 and the second tubular stent 12 may also be formed by laser engraving.

Preferably, the first tubular stent 11 is covered with a film, and at least the portion of the second tubular stent 12 protruding from the first tubular stent 11 is covered with a film. The coated membrane may be, for example, a silicone membrane. The tectorial membrane can effectively prevent the tissue from growing in and is convenient for the tissue to be taken out. Preferably, the portion of the second tubular stent 12 inserted into the first tubular stent 11 is not covered with a film or is only partially covered with a film, for example, only the portion of the second tubular stent close to the distal opening 11a of the first tubular stent 11 is covered with a film, which is beneficial to reduce resistance when the stent 10 is released from the introducer, and facilitates the introduction of the stent 10 into a thinner introducer. Further, a membrane edge may be formed on at least one of the proximal and distal openings 11a and 11b of the first tubular stent 11 and the opening of the second end 12b of the second tubular stent 12 opposite to the first end 12a to reduce irritation to human tissue.

In other embodiments, the first tubular stent 11 and the second tubular stent 12 of the biliary stent 10 are formed of a degradable material.

In some embodiments, the first tubular stent 11 and the second tubular stent 12 of the biliary stent 10 may be integrally formed by 3D printing.

Fig. 4 schematically shows an application example of the biliary stent 10 according to the embodiment of the present invention. In this example, a first tubular stent 11 is used to place the common bile duct 1, and a second end (i.e., the end extending from the first tubular stent 11 opposite to the first end 12 a) 12b of a second tubular stent 12 is used to place the cystic duct 2.

According to the embodiment of the invention, since the second tubular stent 12 is nested in the first tubular stent 11, the biliary stent 10 can be implanted at a time by using one implanter. For example, the first tubular stent 11 and the second tubular stent 12, which are radially compressed, are taken into a catheter (not shown) of an introducer, the catheter is advanced into the common bile duct 1 via the duodenal papilla 4a on the duodenum 4 (i.e., the common opening of the common bile duct 1 and the pancreatic duct 5 on the side wall of the duodenum 4), and further into the cystic duct 2, and then the catheter is withdrawn so that the first tubular stent 11 remains inside the common bile duct 1, and the second tubular stent 12 remains inside the cystic duct 2 from the second end 12b of the first tubular stent 11. Therefore, the implantation operation can be simplified, the implantation success rate can be improved, and the pain of the patient can be reduced.

In the example shown in fig. 4, after the biliary stent 10 is implanted, the first and second tubular stents 11, 12 respectively open the common bile duct 1 and the cystic duct 2, and create a temporary passage for endoscopic surgery, so that crushed stone (stones and/or crushed stones) can be removed from the gallbladder 3 via the cystic duct 2. Specifically, the choledochoscope can enter the first tubular stent 11 placed in the common bile duct 1 through the large papilla 4a of the duodenum 4, and at the moment, the first tubular stent 11 stretches the common bile duct 1 to form a clear passage, and the view is clear, so that the opening of the first end 12a of the second tubular stent 12 inserted in the first tubular stent 11 can be easily found, and the gallbladder 3 can be accessed through the cystic duct 2 along the passage formed by the second tubular stent 12. Because the cystic duct is provided with the wrinkle structure, the choledochoscope is difficult to pass, so the operation of taking the crushed stone from the gallbladder through the cystic duct under the endoscope can not be finished in the prior art.

Meanwhile, as described above, in the biliary stent 10 according to the embodiment of the present invention, the passage p is formed between the inner wall of the first tubular stent 11 and the outer wall of the second tubular stent 12. After the biliary stent 10 is placed, when bile in the intrahepatic bile duct (e.g., the left hepatic duct 6 and the right hepatic duct 7 shown in fig. 4) flows from the common hepatic duct 8 to the common bile duct 1, the bile can flow into the duodenum 4 through the passage p, so that drainage can be effectively realized and/or obstruction can be prevented, and postoperative acute cholangitis caused by obstruction can be avoided.

It should be understood that, unlike the biliary stent 10 using the inside-outside nesting structure according to the embodiment of the present invention, if a single tubular stent (not shown) is used, extending from the common bile duct 1 all the way into the cystic duct 2, since the common bile duct 1 may be in a state of wall contraction or peristalsis, it is not guaranteed that an effective path is formed between the inserted single tubular stent and the common bile duct for discharging bile in the intrahepatic bile duct, obstruction is easily formed, operational risk is increased, and great pain is brought to the patient.

It can be seen that the biliary stent 10 according to an embodiment of the present invention can not only establish a temporary passage for endoscopic surgery, but also ensure normal discharge of bile from the intrahepatic bile duct, preventing the formation of obstruction, as compared to a single tubular stent.

In the application example of the biliary stent 10 according to the embodiment of the present invention shown in fig. 4, the diameter D1 (see fig. 5) of the first tubular stent 11 may be 6-12mm, preferably 8-10 mm; the diameter D2 (see FIG. 5) of the second tubular stent 12 is 3-7mm, preferably 3-4 mm. The optimal selection of the stent diameter not only takes into account the characteristics of the common bile duct 1 and the cystic duct 2, but also intends to form a passage p of an appropriate size between the inner wall of the first tubular stent 11 and the outer wall of the second tubular stent 12 to effectively discharge bile in the intrahepatic bile duct and prevent obstruction.

An example of an application of the biliary stent 10 according to an embodiment of the present invention is described above with reference to fig. 4. It should be understood that the biliary stent 10 may also be used in other situations according to embodiments of the present invention. In particular, the biliary stent 10 may also be used for lithotripsy or drainage of the intrahepatic bile duct (i.e., the left 6 or right 7 hepatic ducts), as shown in fig. 5.

As shown in fig. 5, in lithotripsy or drainage of the intrahepatic bile duct, the first tubular stent 11 is used for placement into the common bile duct 1, and the second end 12b of the second tubular stent 12, which is opposite to the first end 12a thereof inserted into the first tubular stent 11, is used for placement into the intrahepatic bile duct, i.e., the left hepatic duct 6 or the right hepatic duct 7 (the left hepatic duct 6 in the example shown in fig. 5). Since the biliary stent 10 is applied in the intrahepatic duct lithotripsy or drainage condition in a manner similar to that described above with reference to fig. 4, further description thereof is omitted.

Referring back to fig. 1-3, preferably, an enlarged end 12c may be provided at the second end 12b of the second tubular stent 12 for preventing migration. For example, as shown in fig. 4, the second end 12b of the second tubular stent 12 is preferably positioned at the entrance of the gallbladder 3 when the cystic duct 2 is inserted, for preventing the second tubular stent 12 from escaping/withdrawing away from the gallbladder 3. The enlarged end 12c is preferably formed as a trumpet-shaped opening. This shape conforms to the shape of the entrance to the gallbladder 3 and facilitates withdrawal of a stone from the gallbladder 3 after grasping it by, for example, a stone retrieval net (not shown) of the choledochoscope. The enlarged end 12c may also have any other shape suitable for various applications, such as a mushroom shape, etc. It should be understood that the second end 12b of the second tubular stent 12 may also be free of an enlarged end in the case where, for example, the stent 10 is used for intrahepatic choledocholithiasis (see fig. 5).

Referring next to fig. 6, fig. 6 schematically illustrates various part sizes of a biliary stent according to an embodiment of the present invention.

As already described above, the diameter D1 of the first tubular stent 11 and the diameter D2 of the second tubular stent 12, in addition to taking into account matching the characteristics of the tubular tissues (e.g. common bile duct 1, cystic duct 2) in which these two stent sections are intended to be placed, are further preferably designed to enable an effective passage p to be formed between the inner wall of the first tubular stent 11 and the outer wall of the second tubular stent 12.

As shown in FIG. 6, the first tubular stent 11 has a length L1, and the portion of the second tubular stent 12 extending out of the first tubular stent 11 has a length L2. It will be appreciated that length L1 and length L2 should take into account the length characteristics of the tubular tissue into which first and second tubular stents 11, 12 are intended to be placed. Furthermore, according to the preferred embodiment of the present invention, the length L1 and the length L2 may be further optimally designed to have better adaptability to different patients. In particular, the length L1 of the first tubular stent 11 may be less than the length of the tubular tissue in which it is intended to be placed. Referring to the application examples shown in FIGS. 4 and 5, considering that the length of the common bile duct is generally 4 to 8cm, the length L1 of the first tubular stent 11 may be 3 to 8cm, preferably 4 to 6 cm. The length L2 of the portion of the second tubular stent 12 extending beyond the first tubular stent 11 may be greater than the length of the tubular tissue in which it is intended to be placed, and the length L2 may be 3-12cm depending on the application. When the stent 10 is used for cholecystectomy as shown in fig. 4, the length of the portion of the second tubular stent 12 extending from the first tubular stent 11 may be 3-6 cm. When the stent 10 is used for intrahepatic duct lithotripsy as shown in fig. 5, the length of the portion of the second tubular stent 12 protruding from the first tubular stent 11 may be 6-12 cm.

The optimized design of the length L1 and the length L2 is not only beneficial to improving the adaptability of the stent, but also beneficial to the disposable implantation of the biliary stent 10 by a single implanter. Specifically, since the first tubular stent 11 has a larger diameter than the second tubular stent 12, the first tubular stent 11, when radially compressed and received in the catheter of the introducer, generates a larger axial sliding resistance in the catheter, which is disadvantageous in that the stent 10 is pushed out of the catheter; according to the embodiment of the invention, the length L1 of the first tubular stent 11 is properly reduced under the condition of not influencing the nesting and the connection of the first tubular stent 11 and the second tubular stent 12, which is beneficial to reducing the resistance of the stent 10 in the implantation operation, improving the operation efficiency and improving the feeling of a patient.

Further, as has been discussed above, in the biliary stent 10 according to the embodiment of the present invention, the nesting structure/nesting sections 10a of the first tubular stent 11 and the second tubular stent 12 enable the one-time implantation of two stents for different sites, and advantageously enable the formation of a passage p between the two stents, ensuring the normal drainage of bile juice in the intrahepatic bile duct. Moreover, in accordance with a preferred embodiment of the present invention, the nested configuration also facilitates the introduction of, for example, a cholangioscope into the second tubular stent 12. Specifically, the choledochoscope first enters the first tubular stent 11 and advances to some extent under the guidance of the first tubular stent 11; at this time, since the first end 12a of the second tubular stent 12 is inserted and fixed in the first tubular stent 11, the choledochoscope can more easily find the opening of the first end 12a along the passage formed by the first tubular stent 11 and more easily enter the opening. This is extremely advantageous for a choledochoscope operation.

To this end, the nesting section 10a preferably extends for a certain length d to ensure a stable nesting relationship between the first and second tubular stents 11, 12. In some embodiments, the length d of the nested section 10a is preferably equal to or greater than 2mm, more preferably equal to or greater than 1 cm.

For ease of understanding, fig. 7 shows a stent 10' according to a pair of scales. In the comparative example shown in fig. 7, the first stent 11 ' and the second stent 12 ' of the stent 10 ' are connected to each other only by the tube walls of the ends, without forming a nesting of a certain depth/length (corresponding to a very small length d as shown in fig. 6). This results in that, as shown in fig. 7, after the stent 10 'is placed into the tubular tissue, the first stent 11' and the second stent 12 'cannot be brought into or maintained in a nested relationship, so that the opening 12 a' of the second stent 12 'is greatly deviated from the direction of the first stent 11'. It will be appreciated that in this case, after the choledochoscope has been passed out of the first stent 11 ', it is not easy to find the opening 12 a' of the second stent 12 ', while at the same time, after the choledochoscope has been advanced to a longer depth from the large duodenal papilla 4a through the common bile duct 1, it is very difficult to control the direction of the choledochoscope, and it is more difficult to advance the choledochoscope into the opening 12 a' which cannot be stably positioned.

In contrast, the biliary stent 10 according to the embodiment of the present invention can provide an advantageous guiding effect for a choledochoscope because a nested structure, particularly a nested structure of a certain length d, is formed between the first tubular stent 11 and the second tubular stent 12. Moreover, as the length d increases, the cholangioscope can more easily enter the second tubular stent 12 because the first end 12a of the second tubular stent 12 is closer to the proximal end opening 11a of the first tubular stent 11.

Further, the length d of the nested section 10a can also be optimized to facilitate the insertion operation at the same time. According to a preferred embodiment, the ratio of the length d of the nested section 10a to the length L1 of the first tubular stent 11 is less than or equal to 0.6. This is to take into account that the portion of the stent 10 in the nested section 10a after radial compression is the largest in diameter relative to the rest of the stent 10, and the resistance created in the introducer catheter is also the largest, so in order to reduce the push/exit resistance at the time of insertion, it is preferable to make the length d of the nested section 10a smaller.

The above description is only a preferred embodiment of the application and is illustrative of the principles of the technology employed. It will be appreciated by a person skilled in the art that the scope of the invention as referred to in the present application is not limited to the embodiments with a specific combination of the above-mentioned features, but also covers other embodiments with any combination of the above-mentioned features or their equivalents without departing from the inventive concept. For example, the above features may be replaced with (but not limited to) features having similar functions disclosed in the present application.