Extensible covered stent for assisting pancreatic stump digestive tract anastomosis

Abstract

The invention discloses an extendable covered stent for assisting pancreatic stump digestive tract anastomosis, relates to the technical field of medical equipment, solves the problem of pancreatic fistula which cannot be avoided in current pancreatic stump anastomosis, and comprises an equal-diameter integrated stent, an equal-diameter independent stent and a variable-diameter independent stent, the covered stents with different diameters are selected to adapt to the inner diameter of a main pancreatic duct, a supporting internal channel is formed after the stents are released, pancreatin is prevented from permeating into the abdominal cavity, and therefore the risk of pancreatic fistula in traditional anastomosis is changed; when the tension of the anastomotic stoma is too high and even the anastomotic stoma is cracked, the membrane structure with the extendable characteristic plays a buffering role, prevents the cracking, keeps the connectivity of a channel, and prevents pancreatin and digestive juice from flowing into the abdominal cavity, so that the occurrence of complications is effectively reduced, and the possibility of pancreatic fistula is reduced to the greatest extent.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, specifically to an extendable coated stent for assisting pancreatic stump digestive tract anastomosis. Background Art

[0002] In the technical field involved in the invention of the present invention, pancreatic stump anastomosis has been a medical problem for a century. The challenge lies in the fact that the pancreatic duct and pancreatic tissue are small and fragile, and are prone to complications such as pancreatic leakage and pancreatic fistula. In recent years, with the advancement of medical technology and the accumulation of surgical experience, the pancreatic stump anastomosis technology has been improved. The use of minimally invasive surgery, auxiliary instruments and high-definition microscopes and other technologies has improved the accuracy and safety of the operation. Adequate preoperative evaluation and surgical planning are also key to ensuring the success of the operation. Although it is a complex surgical procedure, through the support of a highly professional team and equipment, close cooperation and careful operation, the pancreatic stump anastomosis technology is expected to be further improved, bringing more hope to patients.

[0003] The anastomosis methods of the stump pancreas mainly include pancreatic-gastric anastomosis and pancreatic-small intestine anastomosis. In pancreaticojejunal anastomosis, it can be divided into binding anastomosis and pancreatic duct-mucosa end-to-side anastomosis of pancreas-small intestine, and there are also many improved methods. Regardless of the anastomosis method used, the risk of failure of pancreaticogastric or pancreaticojejunal anastomosis is extremely high because the pancreatic tissue morphology is completely different from the gastrointestinal tract. Rupture of the anastomosis can cause pancreatic enzymes, and even small intestinal fluid and bile to enter the abdominal cavity through the anastomosis, causing pancreatic fistula.

[0004] According to the latest scientific research progress, the root cause of pancreatic stump anastomosis failure is the high biological activity of the pancreatic parenchyma. After physical damage such as cutting and suturing, and chemical damage such as reflux pancreatitis, the pancreatic stump will experience edema and inflammatory reactions, which will lead to increased anastomotic tension and rupture. So far, no pancreatic stump anastomosis method can guarantee that the anastomosis will not crack, which is a difficult problem that still needs to be solved.

[0005] During the operation, doctors usually choose a suitable support tube to assist the anastomosis of the pancreatic stump according to the diameter of the main pancreatic duct. However, there is currently no widely used professional pancreatic stump anastomosis support tube, and most doctors can only use local materials according to the on-site conditions, such as using infusion tubes, catheters, etc. Some doctors may use customized support tubes or stents, but they usually only play a drainage role and have not conducted in-depth research and design on the mechanism of pancreatic fistula. It is generally believed that factors leading to the failure of pancreaticojejunostomy include the main pancreatic duct diameter of the pancreas less than 3 mm and the softness of the pancreatic parenchyma. However, despite the different conditions of patients, the existing anastomosis methods do not use different operating techniques according to the different conditions of the patients. Instead, more emphasis is placed on choosing an anastomosis method that the surgeon is familiar with, because a surgeon can usually only master one anastomosis technique.

[0006] Traditionally, it is believed that no matter what method is used to perform pancreatic stump anastomosis, pancreatic fistula is inevitable. However, the new technology, which uses a specially designed pancreatic stump anastomosis stent with an anchored cap-shaped buffer membrane structure, may provide a new idea for solving this problem. The specially designed pancreatic stump anastomosis stent with the new technology can provide additional protection at the anastomotic site, blocking the connection between anastomotic dehiscence and pancreatic fistula. Through the structure of the anchored cap-shaped buffer membrane, the stent can be firmly fixed at the anastomotic site, preventing pancreatic fluid from leaking out, so that even if anastomotic dehiscence occurs, pancreatic fistula will not occur.

[0007] This innovative pancreatic stump anastomosis covered stent technology may bring a major breakthrough in the field of pancreatic surgery, reduce the risk of pancreatic fistula, and improve the success rate of surgical treatment. It is hoped that this technology can be studied more and applied clinically to provide patients with safer and more effective solutions for surgical treatment. This innovative technology may bring revolutionary changes to pancreatic stump anastomosis surgery in the future.

[0008] For example, the invention named as digestive tract stent and with publication number CN116473723A comprises: a stent body which is a hollow tubular member; and a fixing mechanism which is fixed to at least one end of the stent body in the axial direction and protrudes from the outer peripheral surface of the stent body in the radial direction of the stent body.

[0009] The existing technology has the technical problem that it cannot reduce the diameter to match the patient's digestive tract.

[0010] For example, the invention named gastric diverter and its digestive tract stent, with publication number CN108635092B, includes an upper stent, a lower stent and a connecting piece; in the unfolded shape, the upper stent is provided with a first opening on the top and a second opening on the bottom, the lower stent is provided below the upper stent, the lower stent is provided with a third opening on the top and a fourth opening on the bottom, the upper stent is connected to the lower stent by a plurality of connecting pieces, the fourth opening of the lower stent is connected to the membrane tube, and the unfolded upper stent and the lower stent cannot pass through the opened gastric pyloric opening, and the connecting piece can pass through the gastric pyloric opening or be inserted at the gastric pyloric opening.

[0011] The existing technology has the technical problem of not being able to flexibly stretch and elastically adapt to the deformation of the digestive tract.

[0012] For example, the invention entitled "A degradable digestive tract stent and its preparation method" with publication number CN116439877A comprises a middle section and expansion ends connected to both ends of the middle section. The middle section and the expansion ends are integrally formed, and the degradable digestive tract stent is subjected to radiation modification treatment.

[0013] The existing technology has the technical problem of being unable to form local deformation and reliably support the internal channel. Summary of the invention

[0014] In view of the deficiencies of the prior art, the present invention provides an extendable covered stent for assisting pancreatic stump digestive tract anastomosis, solving the problem of pancreatic fistula that cannot be avoided in current pancreatic stump anastomosis surgery.

[0015] To achieve the above objectives, the present invention is implemented through the following technical solutions: an extendable coated stent is used to assist in the anastomosis of the digestive tract of the pancreatic stump, including an equal-diameter integrated stent, an equal-diameter independent stent and a variable-diameter independent stent, wherein the equal-diameter integrated stent, the equal-diameter independent stent and the variable-diameter independent stent are covered with a coating, one end of the equal-diameter integrated stent is connected to one end of the equal-diameter independent stent, and the other end of the equal-diameter independent stent is connected to the thin end of the variable-diameter independent stent, and the coated stent is in a compressed state when not released, and its outer diameter is smaller than the corresponding inner diameter of the main pancreatic duct; when the stent is released, the outer diameter is larger than the inner diameter of the corresponding main pancreatic duct, and the outer membrane is attached to the inner wall of the main pancreatic duct to block pancreatic enzymes from flowing into the abdominal cavity through the gap, and the inner cavity is the channel for the pancreatic enzymes of the pancreatic stump to circulate.

[0016] Preferably, the equal-diameter integrated bracket is an elastic memory metal mesh, the equal-diameter integrated bracket is a tube body, and the equal-diameter integrated bracket grid is a cylindrical rhombus.

[0017] Preferably, the equal-diameter independent brackets are elastic memory wire rings, the equal-diameter independent brackets are parallel Z-shaped ring bodies, and the equal-diameter independent brackets are not fixedly connected.

[0018] Preferably, the diameter-variable independent bracket is a parallel body of Z-shaped rings, the diameter-variable independent bracket is a trumpet-shaped cylinder, the diameter-variable independent brackets are not fixedly connected to each other, and a circular ring body is arranged at the thick and short end of the diameter-variable independent bracket.

[0019] Preferably, the equal-diameter integrated bracket and the equal-diameter independent bracket have the same diameter, and the thin end of the variable-diameter independent bracket has the same diameter as the equal-diameter integrated bracket and the equal-diameter independent bracket.

[0020] The metal stent material is elastic memory metal, and the specification (diameter) of the variable diameter independent stent is determined according to the inner diameter and outer diameter of the coated stent of the equal diameter integrated stent and the equal diameter independent stent.

[0021] Preferably, the coating is a water-impermeable film, which can prevent liquid from seeping through the coating. The coating is a stretchable flexible film that can be stretched and compressed. Selectable materials include expanded polytetrafluoroethylene (ePTFE), silicone, PTU, etc.

[0022] Preferably, the coating is sleeved on the outside of the equal-diameter integrated stent, the equal-diameter independent stent and the variable-diameter independent stent.

[0023] Preferably, the coating is sleeved on the inner sides of the equal-diameter integrated stent, the equal-diameter independent stent and the variable-diameter independent stent.

[0024] Preferably, the coating is mounted on both inner and outer sides of the equal-diameter integrated bracket, the equal-diameter independent bracket and the variable-diameter independent bracket.

[0025] Preferably, the thick end of the coating is provided with an annular surface, and the annular surface and the thick end of the variable diameter independent stent are on the same plane.

[0026] Beneficial Effects

[0027] The present invention provides an extendable covered stent for assisting pancreatic stump digestive tract anastomosis. The present invention selects covered stents of different diameters to adapt to the inner diameter of the main pancreatic duct. After the stent is released, it forms a supporting internal channel to block pancreatic enzymes from penetrating into the abdominal cavity, thereby changing the risk of pancreatic fistula in traditional anastomosis. When the tension of the anastomotic stoma is too high or even cracks, the membrane structure with the extendable characteristics plays a buffering role to prevent cracking and maintain the connectivity of the channel, while preventing pancreatic enzymes and digestive fluids from flowing into the abdominal cavity, thereby effectively reducing the occurrence of complications, and transforming the traditional high-risk intestinal (stomach)-main pancreatic duct anastomosis into a low-risk covered-intestinal (stomach) anastomosis + high-risk intestinal (stomach)-main pancreatic duct anastomosis, thereby minimizing the possibility of pancreatic fistula. This technical solution fundamentally changes the risk of pancreatic fistula in pancreatic stump anastomosis surgery by selecting a covered stent of appropriate specifications and utilizing its characteristics, thereby improving the safety and success rate of the surgery, and is expected to become an innovative solution to improve the treatment effect of patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention provides a schematic structural diagram of the non-stretched state of the extendable coated stent used for assisting pancreatic stump digestive tract anastomosis after three-dimensional release.

[0029] Figure 2 This is a schematic diagram of the main structure of the extendable covered stent used for assisting pancreatic stump digestive tract anastomosis created by the present invention, in a released and non-stretched state.

[0030] Figure 3 The present invention provides a schematic diagram of the structure of the extendable covered stent in the auxiliary pancreatic stump digestive tract anastomosis created by the present invention after release and in a non-stretched state as viewed from above.

[0031] Figure 4 This is a schematic diagram of the main structure of the present invention in a non-stretched state after the equal-diameter integrated stent using the extendable covered stent for assisting pancreatic stump digestive tract anastomosis is released.

[0032] Figure 5 This is a schematic diagram of the main structure of the present invention in a non-stretched state after the release of the equal-diameter independent stent using an extendable covered stent for assisting pancreatic stump digestive tract anastomosis.

[0033] Figure 6 The present invention provides a schematic diagram of the structure of the auxiliary pancreatic stump digestive tract anastomosis using a variable-diameter independent stent with an extendable coated stent after release and in a non-stretched state.

[0034] Figure 7 The present invention provides a schematic structural diagram of the state after intraoperative placement of the extendable covered stent used for assisting pancreatic stump digestive tract anastomosis.

[0035] Figure 8 The present invention provides a schematic structural diagram of the state after anastomotic stoma dehiscence occurs in the auxiliary pancreatic stump digestive tract anastomosis using the extendable covered stent created by the present invention.

[0036] In the figure: 1. Equal-diameter integrated bracket; 2. Equal-diameter independent bracket; 3. Variable-diameter independent bracket; 4. Covering; DETAILED DESCRIPTION

[0037] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The detailed description is as follows.

[0038] See also Figure 1-8 The present invention provides a technical solution: an extendable coated stent is used to assist in the anastomosis of the digestive tract of the pancreatic stump, including an equal-diameter integrated stent 1, an equal-diameter independent stent 2 and a variable-diameter independent stent 3, wherein the equal-diameter integrated stent 1, the equal-diameter independent stent 2 and the variable-diameter independent stent 3 are covered with a coating 4, one end of the equal-diameter integrated stent 1 is connected to one end of the equal-diameter independent stent 2, and the other end of the equal-diameter independent stent 2 is connected to the thin end of the variable-diameter independent stent 3, and the coated stent is in a compressed state when not released, and its outer diameter is smaller than the corresponding inner diameter of the main pancreatic duct; when the stent is released, the outer diameter is larger than the inner diameter of the corresponding main pancreatic duct, and the outer membrane is attached to the inner wall of the main pancreatic duct to block pancreatic enzymes from flowing into the abdominal cavity through the gap, and the inner cavity is a channel for the pancreatic enzymes of the pancreatic stump to circulate.

[0039] This embodiment is further configured such that the equal-diameter integrated bracket 1 is an elastic memory metal mesh, the equal-diameter integrated bracket 1 is a tube body, and the grid of the equal-diameter integrated bracket 1 is a cylindrical rhombus.

[0040] The present embodiment is further configured such that the equal-diameter independent brackets 2 are elastic memory wire rings, the equal-diameter independent brackets 2 are parallel Z-shaped ring bodies, and the equal-diameter independent brackets 2 are not fixedly connected to each other.

[0041] The present embodiment is further configured such that the variable diameter independent bracket 3 is a Z-shaped ring parallel body, the variable diameter independent bracket 3 is a trumpet-shaped cylinder, the variable diameter independent bracket 3 is not fixedly connected to each other, and a circular ring body is arranged at the thick and short end of the variable diameter independent bracket 3.

[0042] This embodiment is further configured such that the equal-diameter integrated bracket 1 and the equal-diameter independent bracket 2 have the same diameter, and the thin end of the variable-diameter independent bracket 3 has the same diameter as the equal-diameter integrated bracket 1 and the equal-diameter independent bracket 2 .

[0043] The metal bracket material is a memory metal with elasticity, and the specification (diameter) of the variable diameter independent bracket 3 is determined according to the inner diameter and outer diameter of the equal diameter integrated bracket 1 and the equal diameter independent bracket 2 .

[0044] The present embodiment is further configured such that the coating 4 is a water-impermeable film, which can prevent liquid from seeping through the coating 4. The coating 4 is a stretchable flexible film that can be stretched and compressed. Selectable materials include expanded polytetrafluoroethylene (ePTFE), silicone, PTU, etc.

[0045] This embodiment is further configured such that the coating 4 is sleeved on the outside of the equal-diameter integrated bracket 1 , the equal-diameter independent bracket 2 and the variable-diameter independent bracket 3 .

[0046] This embodiment is further configured such that the coating 4 is sleeved on the inner sides of the equal-diameter integrated bracket 1 , the equal-diameter independent bracket 2 and the variable-diameter independent bracket 3 .

[0047] This embodiment is further configured such that the coating 4 is sleeved on both inner and outer sides of the equal-diameter integrated bracket 1 , the equal-diameter independent bracket 2 and the variable-diameter independent bracket 3 .

[0048] This embodiment is further configured such that the thick end of the coating 4 is provided with a circular ring surface, and the circular ring surface and the thick end of the variable diameter independent bracket 3 are on the same plane.

[0049] The detailed connection means are well known in the art; Figure 1-8As shown in the anastomosis of the pancreatic stump, common methods include pancreatic-gastric anastomosis and pancreatic-small intestine anastomosis, among which pancreaticojejunal anastomosis includes binding anastomosis and pancreatic duct-mucosal end-to-side anastomosis of pancreas-small intestine, and there are also many improved methods. However, the pancreatic tissue is completely different from the gastrointestinal tissue, resulting in a very high risk of failure of the pancreaticojejunal anastomosis. Anastomotic rupture can cause pancreatic enzymes, and even small intestinal fluid and bile, to enter the abdominal cavity through the anastomosis, inducing pancreatic fistula. The introduction of a specially designed anchored cap-shaped buffer membrane structure for pancreatic stump anastomosis covered stent may provide a new idea for solving this problem; in the new technology, the specially designed pancreatic stump anastomosis covered stent can provide additional protection for the anastomosis, blocking the association between anastomotic rupture and pancreatic fistula. Through the structure of the anchored cap-shaped buffer membrane, the stent can be firmly fixed at the anastomosis position, effectively preventing pancreatic fluid extravasation. Even if the anastomosis is broken, it will not lead to pancreatic fistula. The application of this new technology brings more safety and success possibilities to pancreatic stump anastomosis, thereby reducing the risk of complications and improving the effect of surgical treatment.

[0050] According to the diameter of the main pancreatic duct, different specifications of covered stents are selected, including equal-diameter integrated stent 1 and equal-diameter independent stent 2. The outer diameter of these two stents is larger than the diameter of the main pancreatic duct. They are in a compressed state before being placed in the main pancreatic duct, and are placed in the main pancreatic duct and released during the operation. Since the outer diameter of the stent is larger than the diameter of the main pancreatic duct, the equal-diameter integrated stent 1 and the equal-diameter independent stent 2 can be tightly combined with the inner wall of the main pancreatic duct to prevent pancreatic enzymes from the pancreatic stump from infiltrating into the abdominal cavity through the gap between the two. In addition, the friction between the stent and the inner wall of the main pancreatic duct also prevents the stent and the main pancreatic duct from relative displacement.

[0051] This design is intended to provide additional protection to ensure the stability and effectiveness of the coated 4-stent at the anastomosis, prevent the leakage of pancreatic enzymes and other complications, thereby improving the success rate of surgical treatment and patient safety.

[0052] The variable diameter independent stent 3 is placed in the small intestine (stomach) cavity during the operation, and the edge of the larger diameter of the variable diameter independent stent 3 is anchored on the inner side of the small intestine (stomach) cavity by suture or nail; the gap between the variable diameter independent stent 3 and the small intestine (stomach) wall prevents digestive fluid from flowing into the abdominal cavity from the gap; the coating 4 of the covered stent is made of elastic material and is very easy to stretch; when the pancreaticojejunostomy (gastric) anastomosis is edematous and cracked, because the larger diameter of the equal diameter integrated stent 1 has been fixed in the main pancreatic duct, and the variable diameter stent part has also been anchored on the inner wall of the small intestine (stomach), the only part that can be deformed by force is the equal diameter integrated stent 1 and the variable diameter independent stent 3 of the covered stent, which are stretched because of their own extensible characteristics, buffering the tension of the anastomosis and will not crack, and there is still a membrane structure to prevent pancreatic enzymes from flowing into the abdominal cavity from the pancreatic duct, and prevent pancreatic fistula after pancreaticojejunostomy. The inner cavity of the covered stent is the channel for pancreatic enzymes to circulate in the pancreatic stump.

[0053] This design structure plays an important role in pancreaticojejunostomy (gastrostomy). Through the characteristics and functions of the covered stent, it can effectively avoid the occurrence of various complications and improve the surgical efficacy and treatment safety.

[0054] When in use, after the pancreatic stump and the small intestine (stomach) anastomosis surface are prepared, one end of the equal-diameter integrated stent 1 of the pancreatic stump anastomosis stent with a cap-shaped buffer membrane structure in a gripped state is placed into the main pancreatic duct and then released; a small incision (about 5 mm) is made in the small intestine (stomach) and then the variable-diameter independent stent 3 is placed into the small intestine (stomach) cavity, and fixed to the inner wall of the small intestine (stomach) by sutures at multiple points (solid line in the figure), which is the inner suture; then, the main pancreatic duct of the pancreas is anastomosed with the small intestine (stomach) wall at multiple points (dashed line in the figure), and the suture here is the outer suture. The outer suture here is the traditional main pancreatic duct-small intestine (stomach) anastomosis, which is very fragile. When the pancreaticojejunostomy (gastric) anastomosis swells and cracks, since the equal-diameter integrated stent 1 has been fixed in the main pancreatic duct and the variable-diameter independent stent 3 has been sutured and fixed to the inner wall of the small intestine (stomach) cavity with the help of its edges, the only ones that can be subjected to force and deform are the equal-diameter independent stent 2 and part of the variable-diameter independent stent 3. Due to their own extensible characteristics, they buffer the tension of the anastomosis and will not crack. There is still a membrane structure to prevent pancreatic enzymes from flowing into the abdominal cavity from the pancreatic duct, thereby preventing pancreatic fistula after pancreaticojejunostomy.

[0055] The invention can provide additional protection: the coated stent can prevent anastomosis rupture, and prevent substances such as pancreatic enzymes, small intestinal fluid and bile from entering the abdominal cavity through the anastomosis, effectively preventing the occurrence of pancreatic fistula; increase stability: the stent is firmly fixed at the anastomosis position, which can prevent the stent and the anastomosis from shifting, and improve the stability and success rate of the operation; relieve the tension of the anastomosis: the characteristics of the stent enable it to buffer the tension when the anastomosis is edematous and cracked, prevent the anastomosis from cracking, and maintain the membrane structure to prevent pancreatic enzyme extravasation; have a channel function: the inner cavity of the coated stent serves as a channel for the circulation of pancreatic enzymes in the pancreatic stump, which helps to maintain normal pancreatic function.

[0056] Matters needing attention in the creation of the present invention: Select appropriate specifications of the covered stent: Select a stent of appropriate specifications according to the diameter of the main pancreatic duct to ensure that the stent can be effectively fixed on the inner wall of the main pancreatic duct; High technical requirements for operation: Precise operation is required during the operation, including the placement and fixation of the stent, requiring the doctor to have good operating skills and experience; Close observation after surgery: After the operation, the patient's condition needs to be closely observed, especially the condition of the anastomosis, and postoperative complications should be discovered and treated in time; Postoperative care and recovery: After the operation, the doctor's orders must be strictly followed, medication should be taken on time, regular follow-up visits should be made, and effective rehabilitation care should be carried out to promote the patient's recovery as soon as possible.

[0057] In summary, this structure can improve the success rate of anastomosis: the device provides additional protection and support to prevent anastomotic rupture and pancreatic enzyme extravasation, effectively prevent the occurrence of postoperative complications such as pancreatic fistula, thereby significantly improving the success rate of anastomosis; reduce the risk of complications: the special design of the device can effectively relieve anastomotic tension, reduce anastomotic edema and dehiscence, and avoid serious postoperative complications such as pancreatic fistula and infection; protect pancreatic function: the device serves as a channel for the circulation of pancreatic enzymes in the pancreatic stump, which helps to maintain the normal function of the pancreas and reduce the occurrence of postoperative pancreatic dysfunction and digestive problems; application of creative methods: through the application of this device, a creative method of anastomosis of the pancreatic stump digestive tract is realized, which effectively solves various problems and challenges existing in traditional anastomosis, and provides new ideas and technical means for surgical treatment; promote postoperative rehabilitation: the special design structure and function of the device help to ensure the safety of patients and surgical effects after surgery, promote patients' rehabilitation and recovery, and improve patients' quality of life.

[0058] In the future, pancreatic stump anastomosis surgery may develop in a more refined and personalized direction. The continuous advancement of medical technology will promote the improvement of surgical technology, from surgical plan design to operation technology and the selection of instruments and equipment, which will be more flexible and precise. At the same time, the design of personalized treatment plans will pay more attention to customizing the most suitable treatment plan according to the patient's specific situation and pathological characteristics, so as to improve the surgical treatment effect and reduce the risk of complications. With the continuous application of new technologies, such as robot-assisted surgery and three-dimensional printing technology, the accuracy and safety of pancreatic stump anastomosis surgery will be further improved. Through continuous research and innovation, new treatment strategies and surgical methods may be explored in the future to improve the level and effect of surgical treatment. In summary, pancreatic stump anastomosis surgery will develop in a safer, more effective and personalized direction in the future, providing patients with better treatment effects and quality of life.

[0059] It should be noted that, in this document, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0060] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An extendable covered stent is used to assist pancreatic stump digestive tract anastomosis, comprising an equal-diameter integrated stent (1), an equal-diameter independent stent (2) and a variable-diameter independent stent (3), characterized in that: The equal-diameter integrated bracket (1), the equal-diameter independent bracket (2), and the variable-diameter independent bracket (3) are covered with a coating (4); one end of the equal-diameter integrated bracket (1) is connected to one end of the equal-diameter independent bracket (2), and the other end of the equal-diameter independent bracket (2) is connected to the thin end of the variable-diameter independent bracket (3).

2. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The equal-diameter integrated bracket (1) is an elastic memory metal mesh, the equal-diameter integrated bracket (1) is a tube body, and the mesh of the equal-diameter integrated bracket (1) is a cylindrical rhombus.

3. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The equal-diameter independent bracket (2) is an elastic memory metal wire ring, the equal-diameter independent bracket (2) is a parallel body of Z-shaped rings, and the equal-diameter independent brackets (2) are not fixedly connected to each other.

4. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The diameter-variable independent bracket (3) is a parallel body of Z-shaped rings, the diameter-variable independent bracket (3) is a trumpet-shaped cylinder, the diameter-variable independent brackets (3) are not fixedly connected to each other, and a circular ring body is arranged at the thick and short end of the diameter-variable independent bracket (3).

5. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The equal-diameter integrated bracket (1) and the equal-diameter independent bracket (2) have the same diameter, and the thin end of the variable-diameter independent bracket (3) has the same diameter as the equal-diameter integrated bracket (1) and the equal-diameter independent bracket (2).

6. The extendable coated (4) stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The covering film (4) is a water-impermeable film, and the covering film (4) is a stretchable flexible film.

7. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The coating (4) is sleeved on the outside of the equal-diameter integrated bracket (1), the equal-diameter independent bracket (2) and the variable-diameter independent bracket (3).

8. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The coating (4) is sleeved on the inner sides of the equal-diameter integrated bracket (1), the equal-diameter independent bracket (2) and the variable-diameter independent bracket (3).

9. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The coating (4) is sleeved on both inner and outer sides of the equal-diameter integrated bracket (1), the equal-diameter independent bracket (2) and the variable-diameter independent bracket (3).

10. The extendable covered stent for assisting pancreatic stump digestive tract anastomosis according to claim 1, characterized in that: The thick end of the coating (4) is provided with a circular ring surface, and the circular ring surface and the thick end of the variable diameter independent bracket (3) are on the same plane.

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