Biliary tract stent with positioning structure for hepatobiliary pancreatic surgery

Abstract

The invention discloses a biliary tract stent with a positioning structure for hepatobiliary pancreatic surgery, relates to the technical field of biliary tract stents.The biliary tract stent is suitable for treating biliary tract stenosis or obstruction, and comprises a tubular stent body and the positioning structure, the positioning structure comprises a Y-shaped anchoring protrusion and a developing mark, the Y-shaped anchoring protrusion is arranged on the outer wall of the stent, and the developing mark is arranged on the outer wall of the stent. Both the cross section and the vertical section are Y-shaped, the embedding force with the inner wall of the biliary tract is remarkably enhanced, the postoperative displacement risk is reduced, the developing mark adopts iodine-doped polylactic acid or gold rings and tantalum particles, X-ray and ultrasonic bimodal developing is supported, the intraoperative positioning accuracy is improved, the stent body and the anchoring protrusions can be made of degradable materials, the degradation performance is excellent, and the stent is suitable for popularization and application. The stent is suitable for short-term implantation, does not need to be taken out through a secondary operation and is good in biocompatibility, the surface of the stent can be coated with a hydrophilic or antibacterial coating, and inflammation and infection risks are reduced. The manufacturing process adopts extrusion molding, laser cutting, injection molding, hot pressing or mechanical embedding, the process is simplified, the efficiency is high, and the method is suitable for micro bracket production.

Description

Technical Field

[0001] The present invention relates to the technical field of biliary stents, and in particular to a biliary stent with a positioning structure for hepatobiliary and pancreatic surgery. Background Art

[0002] A biliary stent is a tubular medical device that is implanted into the bile duct through endoscopic techniques (such as ERCP, endoscopic retrograde cholangiopancreatography) to maintain bile duct patency and relieve symptoms caused by bile stasis or bile obstruction. Existing biliary stents are usually made of metal materials (such as stainless steel, nickel-titanium alloy) or polymer materials (such as polyurethane, polyethylene), and have certain mechanical strength and flexibility, and can expand in the bile duct and support the stricture segment. Some stents are designed with protrusions or hook-like structures to enhance fixation and prevent postoperative displacement; at the same time, the surface of the stent is often coated with a hydrophilic or antibacterial coating to reduce the risk of inflammation and infection. In addition, to assist in intraoperative positioning, the stent is usually embedded with a contrast marker (such as gold, tantalum and other metal materials) to display the position under X-ray or ultrasound images.

[0003] Although existing biliary stents have achieved certain results in clinical applications, they still have the following limitations: Insufficient fixation stability: Existing stents often feature protrusions or hooks in circular, cylindrical, or unidirectional designs, which have limited ability to fit within the bile duct wall. This makes them prone to displacement or dislodgement, particularly in the complex physiological environment of bile duct peristalsis and bile flow, leading to postoperative complications such as stent obstruction and biliary restenosis. Statistics show that approximately 10-20% of biliary stents experience displacement within six months after surgery.

[0004] Limited positioning accuracy: Existing imaging markers primarily rely on metal materials (such as gold rings and tantalum dots). While effective under X-ray imaging, they lack visualization under ultrasound, limiting intraoperative positioning flexibility. Furthermore, metal markers are non-degradable, and long-term implantation may trigger tissue reactions or impair subsequent imaging diagnoses.

[0005] Biocompatibility Issues: Metal stents (such as nickel-titanium alloys) are suitable for long-term implantation but require secondary surgical removal, increasing patient pain and medical costs. While polymer stents (such as polyurethane) offer some flexibility, some materials lack sufficient degradability, and degradation products may cause local inflammation or tissue hyperplasia. Degradable stents (such as polylactic acid) have been increasingly used for short-term treatment in recent years, but the degradation of their fixed structures and imaging markers has not yet been fully optimized, limiting their clinical adoption.

[0006] Manufacturing Complexity: Existing stent protrusions and imaging markers are typically joined via laser welding, bonding, or mechanical fastening, resulting in complex processes and poor consistency. This is particularly challenging in the production of micro-stents (wall thickness 0.1-0.5 mm), posing challenges to precision and cost control. Furthermore, some stent manufacturing processes involve high-temperature annealing, which may not be suitable for polymer materials, leading to reduced material performance and production efficiency.

[0007] Therefore, in view of the deficiencies of the prior art, the present invention proposes a biliary stent with a positioning structure for hepatobiliary and pancreatic surgery to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to solve the prior art problems raised in the above background technology, and to provide a biliary stent with a positioning structure for hepatobiliary and pancreatic surgery.

[0009] The present invention achieves the above-mentioned object through the following scheme: A biliary stent with a positioning structure for hepatobiliary and pancreatic surgery, comprising: The stent body is a tubular structure suitable for being implanted into the bile duct to maintain bile duct patency; a positioning structure, disposed on the bracket body, the positioning structure comprising at least one anchoring protrusion and at least one developing mark; The anchoring protrusion is provided on the outer wall of the stent body, and both the cross section and the vertical section of the anchoring protrusion are Y-shaped, and are used to engage with the inner wall of the bile duct to enhance the fixation stability; The development marker is embedded in the stent body and is used for development under X-ray or ultrasound imaging to assist intraoperative positioning.

[0010] As a preferred technical solution of the present invention, the stent body is made of a medical polymer material or a metal alloy. The medical polymer material includes polyurethane, polylactic acid or polycaprolactone, and the metal alloy includes nickel-titanium alloy.

[0011] As a preferred technical solution of the present invention, the anchoring protrusions are distributed in a ring shape on the outer wall of the stent body, with a number of 4-8, a height of the anchoring protrusions of 0.3-0.8 mm, and a bifurcation angle of the Y-shaped cross section of 30-60 degrees.

[0012] As a preferred technical solution of the present invention, the anchoring protrusion is made of a degradable flexible material, and the degradable flexible material includes degradable polyurethane, polylactic acid or polycaprolactone, and the anchoring protrusion is integrally formed with the stent body by the following manufacturing method: Provide a degradable flexible material and prepare an anchoring protrusion with a Y-shaped cross-section through an injection molding process. The injection molding temperature is 160-200°C, the pressure is 50-80MPa, and the molding time is 10-20 seconds; performing plasma activation treatment on a predetermined position of the outer wall of the stent body to enhance surface bonding strength; The anchoring protrusion is combined with the stent body by a hot pressing process, with the hot pressing temperature being 100-120°C, the pressure being 5-10N, and the time being 10-15 seconds to form an integrated structure; The one-piece molded bracket is ultrasonically cleaned for 3-5 minutes to remove surface residues.

[0013] As a preferred technical solution of the present invention, the development mark includes iodine-doped polylactic acid, gold rings or tantalum dots. The number of the development marks is 2-4, and they are spaced apart along the longitudinal direction of the stent body at a spacing of 10-30 mm.

[0014] As a preferred technical solution of the present invention, the imaging mark is embedded in the stent body by the following manufacturing method: A laser drilling device is used to form an embedding groove at a predetermined position of the bracket body, wherein the diameter of the embedding groove is 0.5-1 mm, the depth is 0.2-0.5 mm, the laser power is 10-20 W, and the pulse frequency is 50-100 kHz; For iodine-doped polylactic acid developer marking, developer particles with a diameter of 0.5-1 mm were prepared by injection molding at an injection temperature of 160-180°C, a pressure of 50-70 MPa, and a molding time of 10-15 seconds. The developer particles were placed in the embedding groove and fixed by applying a pressure of 5-8 N by a hot pressing process at a temperature of 100-110°C for 10 seconds. For gold rings or tantalum dots, a mechanical pressing process is used to apply a pressure of 5-10N to fix them, followed by electroplating. The electroplating solution includes an electrolyte solution containing gold or tantalum, the current density is 0.5-1A / dm², and the electroplating time is 2-5 minutes. Ultrasonic cleaning of the embedded area was performed for 3-5 minutes to remove residual impurities.

[0015] As a preferred technical solution of the present invention, the surface of the stent body is coated with a hydrophilic coating or an antibacterial coating, the hydrophilic coating comprises polyethylene glycol, and the antibacterial coating comprises silver-containing nanomaterials.

[0016] As a preferred technical solution of the present invention, the hydrophilic coating or antibacterial coating is applied to the stent body by the following manufacturing method: Providing polyethylene glycol or silver-containing nanomaterials as coating materials, placing the stent body in a plasma spraying device with a spraying power of 20-30kW and a spraying distance of 100-150mm; The coating material is deposited on the surface of the stent body by a plasma spraying process, the coating thickness is controlled to be 10-50 μm, and the spraying time is 5-10 minutes; The coated stent body is placed in a vacuum oven and heat treated at 80-100°C for 20-30 minutes to enhance the adhesion of the coating; The coating surface is subjected to UV curing treatment with a UV wavelength of 250-300nm and a curing time of 10-15 minutes to improve the stability and corrosion resistance of the coating.

[0017] As a preferred technical solution of the present invention, the anchoring protrusion is fixed to the stent body by the following mechanical interlocking method: An interlocking groove is formed on the outer wall of the stent body by laser micromachining, wherein the diameter of the interlocking groove is 0.5-1 mm, the depth is 0.3-0.6 mm, and the laser power is 15-25 W; Provided are anchoring protrusions made of a degradable flexible material, including degradable polyurethane, polylactic acid, or polycaprolactone. The anchoring protrusions have a Y-shaped cross-section and a snap-fit ​​structure at the bottom. They are manufactured by injection molding at a temperature of 160-200°C, a pressure of 50-80 MPa, and a molding time of 10-20 seconds. Press the buckle structure of the anchoring protrusion into the fitting groove, and apply a pressure of 8-12N through a mechanical pressing process to lock the anchoring protrusion to the stent body; Ultrasonic cleaning of the mating area was performed for 3-5 minutes to remove processing residues.

[0018] As a preferred technical solution of the present invention, the stent body and the anchoring protrusion are made of a degradable material, the degradable material includes polylactic acid or polycaprolactone, the developing mark is made of iodine-doped polylactic acid, a gold ring or a tantalum particle, and the stent body and the anchoring protrusion are prepared by the following manufacturing method: Placing polylactic acid or polycaprolactone particles in an extrusion molding device, controlling the extrusion temperature at 160-200°C and the screw speed at 30-50 rpm to form a tubular billet; Placing the tubular blank in a laser cutting device, using a laser power of 15-25 W and a cutting speed of 5-10 mm / s to prepare a stent body having a mesh structure; A degradable flexible material is provided, and an anchoring protrusion with a Y-shaped cross-section is prepared by injection molding at an injection temperature of 160-200°C, a pressure of 50-80 MPa, and a molding time of 10-20 seconds; Plasma activation treatment is performed on a predetermined position of the outer wall of the stent body, and the anchoring protrusion is combined with the stent body by a hot pressing process, with the hot pressing temperature being 100-120°C, the pressure being 5-10N, and the time being 10-15 seconds; Performing a final ultrasonic cleaning on the stent for 3-5 minutes to remove surface residues; The stent is sterilized by fumigation with ethylene oxide gas for 4-6 hours to ensure that the product meets medical device standards.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The biliary stent of the present invention significantly improves the ability to fit with the inner wall of the bile duct through the uniquely designed Y-shaped anchoring protrusion. Compared with traditional round or hook-shaped protrusions, the bifurcated structure of the Y-shaped protrusion can more effectively resist the influence of bile duct peristalsis and bile flow, greatly reducing the risk of postoperative displacement or falling off. At the same time, the stent uses iodine-doped polylactic acid as a development marker, supports X-ray and ultrasound dual-modality development, and has clear imaging effects, which significantly improves the accuracy of intraoperative positioning and operational efficiency. This design is particularly suitable for complex biliary environments, ensuring that the stent is accurately implanted in the target position and reducing the need for postoperative adjustments.

[0020] The present invention utilizes biodegradable materials (such as polylactic acid, polycaprolactone, and biodegradable polyurethane) to manufacture the stent body and anchoring protrusions, resulting in excellent biocompatibility and making it particularly suitable for short-term implantation to treat benign biliary strictures or cholelithiasis. The stent gradually degrades within the body, eliminating the need for secondary surgical removal, alleviating patient pain and reducing the medical burden. The iodine-doped polylactic acid imaging marker is also biodegradable, avoiding the tissue reactions that can be associated with long-term implantation of traditional metal markers. Hydrophilic or antimicrobial coatings applied to the stent surface further reduce the risk of inflammation and infection, enhancing postoperative recovery.

[0021] The present invention uses an optimized manufacturing process and adopts efficient methods such as extrusion molding, laser cutting, injection molding, hot pressing or mechanical interlocking to replace the complex welding, bonding or high-temperature annealing steps in traditional stent manufacturing. These processes are particularly suitable for the processing characteristics of degradable polymer materials, ensuring the consistency of the stent structure and the stability of its performance. The simplified process reduces the number of production steps, improves manufacturing efficiency, and reduces costs, making it suitable for large-scale production of micro-biliary stents. The final ultrasonic cleaning and sterilization treatment ensure that the product meets medical device standards and provides reliable protection for clinical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a model diagram of a biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to the present invention.

[0024] Wherein: 1 is the stent body; 2 is the positioning structure; 21 is the anchoring protrusion; 22 is the developing mark. DETAILED DESCRIPTION

[0025] The following will be combined Figure 1 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] like Figure 1 As shown, the biliary stent of the present invention includes a stent body 1 and a positioning structure 2. The stent body 1 is a tubular structure suitable for implantation in the bile duct to maintain bile duct patency. The positioning structure 2 includes an anchoring protrusion 21 and a development marker 22. The anchoring protrusion 21 is provided on the outer wall of the stent body 1 and is Y-shaped in both cross-section and vertical section. It is used to engage with the inner wall of the bile duct to enhance fixation stability. The development marker 22 is embedded in the stent body 1 and is used to be developed under X-ray or ultrasound imaging to assist in intraoperative positioning. The stent body 1 can be made of a medical polymer material (such as degradable polyurethane, polylactic acid, polycaprolactone) or a metal alloy (such as nickel-titanium alloy). The anchoring protrusions 21 are distributed in a ring shape, with a number of 4-8 and a height of 0.3-0.8 mm. The bifurcation angle of the Y-shaped cross section is 30-60 degrees.

[0027] Example 1: Self-expanding metal biliary stent; This embodiment designs a self-expanding metal biliary stent, which is suitable for long-term implantation to treat biliary stenosis or bile duct cancer. The stent body 1 is made of nickel-titanium alloy and has a mesh tubular structure. The diameter in the compressed state is 3 mm, the diameter in the expanded state is 10 mm, the length is 60 mm, and the wall thickness is 0.2 mm.

[0028] The positioning structure 2 includes 6 anchoring protrusions 21 and 3 development marks 22. The anchoring protrusions 21 are made of nickel-titanium alloy and are integrally formed with the stent body 1 through laser micromachining. They are 0.5 mm high, have a Y-shaped cross-section, and a bifurcation angle of 45 degrees. They are distributed in a ring on the outer wall of the stent. There are 6 of them. The Y-shaped design increases the fitting force with the inner wall of the bile duct through the bifurcation structure, and the fixing force is increased by about 30%.

[0029] Manufacturing method: Nickel-titanium alloy wire (0.2 mm in diameter) was used to form a tubular blank through an extrusion molding device. The extrusion temperature was 600-650°C and the screw speed was 20-30 rpm.

[0030] The tubular blank was placed in a laser cutting device, and a laser power of 20 W and a cutting speed of 8 mm / s were used to prepare a mesh tubular structure with a mesh size of 1 × 1 mm.

[0031] Six Y-shaped anchoring protrusions 21 are engraved on the outer wall using a femtosecond laser micromachining device.

[0032] The scaffolds were heat treated at 500°C for 30 minutes to impart self-expanding properties and relieve processing stress.

[0033] The one-piece molded stent was ultrasonically cleaned for 4 minutes at a frequency of 40 kHz to remove surface residues.

[0034] Three gold rings, 0.8 mm in diameter, were embedded as development markers 22, spaced 15 mm apart along the longitudinal direction of the stent. Laser drilling equipment was used to create embedding grooves with a diameter of 0.8 mm and a depth of 0.3 mm. The laser power was 15 W and the pulse frequency was 80 kHz. The gold rings were placed in the embedding grooves and secured by mechanical pressing with a pressure of 8 N. Electroplating was then performed using a gold-containing cyanide solution at a current density of 0.8 A / dm² for 3 minutes. The embedded area was then ultrasonically cleaned for 4 minutes.

[0035] A polyethylene glycol hydrophilic coating with a thickness of 30 μm was applied to the stent surface using plasma spraying equipment at a power of 25 kW, a spray distance of 120 mm, and a spraying time of 8 minutes. The coated stent was then heat-treated in a vacuum oven at 90°C for 25 minutes to enhance coating adhesion. The stent was then cured with UV light at a wavelength of 270 nm for 12 minutes.

[0036] Usage: Preoperatively, the location of the biliary stricture is determined using CT or MRI. Endoscopic endoscopic coronary intervention (ERCP) is used to advance the stent to the target location. After release, the stent expands to 10 mm, with the Y-shaped anchoring projection 21 engaging the biliary tract wall. X-rays are used to confirm the positioning of the gold ring. Postoperative follow-up imaging is used to assess stent patency and stability.

[0037] Example 2: Degradable hot-pressed biliary stent; This embodiment designs a biodegradable plastic biliary stent suitable for short-term implantation (6-12 months) to treat benign biliary strictures. The stent body 1 and anchoring protrusions 21 are made of polylactic acid, with a diameter of 8 mm, a length of 80 mm, and a wall thickness of 0.3 mm. It is non-self-expanding. The positioning structure 2 includes four anchoring protrusions 21 and two imaging markers 22. The anchoring protrusions 21 are made of polylactic acid, 0.4 mm high, and have a Y-shaped cross-section with a bifurcation angle of 30 degrees. They are arranged in a circular pattern and are integrally formed using a hot-pressing process.

[0038] Manufacturing method: Provide polylactic acid particles and form a tubular billet through an extrusion molding device. The extrusion temperature is 180°C and the screw speed is 40rpm.

[0039] The tubular blank was placed in a laser cutting device, and a laser power of 18 W and a cutting speed of 7 mm / s were used to prepare a mesh structure with a mesh size of 0.8×0.8 mm.

[0040] Provide polylactic acid raw material, and prepare Y-shaped anchoring protrusions 21 through injection molding equipment. The injection molding temperature is 170°C, the pressure is 60MPa, and the molding time is 15 seconds to prepare 4 anchoring protrusions 21.

[0041] Plasma activation treatment is performed on predetermined positions on the outer wall of the bracket body 1 to enhance surface bonding strength.

[0042] The Y-shaped anchoring protrusion 21 is placed on the outer wall of the bracket and combined by hot pressing equipment at 110°C and 8N pressure for 15 seconds to form an integrated structure.

[0043] Two iodine-doped polylactic acid developing marks 22 (iodine content 20 wt%) were embedded, with a diameter of 0.6 mm and a spacing of 20 mm. An embedding groove with a diameter of 0.6 mm and a depth of 0.25 mm was formed using a laser drilling device. The laser power was 12 W and the pulse frequency was 60 kHz. The developing particles were prepared by injection molding with an injection temperature of 170°C, a pressure of 60 MPa, and a molding time of 12 seconds. The particles were placed in the embedding groove and fixed by hot pressing (100°C, 6N, 10 seconds).

[0044] The stent surface was coated with a 20-μm-thick antimicrobial coating containing silver nanomaterials. Plasma spraying was performed using a spraying machine with a power of 22 kW, a spray distance of 130 mm, and a spraying time of 6 minutes. The stent was then heat-treated in a vacuum oven at 85°C for 20 minutes and cured with UV light (wavelength 265 nm, 10 minutes). The stent was finally ultrasonically cleaned for 3 minutes at a frequency of 40 kHz to remove surface residues. Sterilization was achieved by fumigation with ethylene oxide gas for 5 hours in accordance with ISO 10993 standards.

[0045] Usage: Preoperatively, ultrasound examination is performed to determine the location of the biliary obstruction, and the stent is advanced to the target location using an endoscope. The Y-shaped anchoring projection 21 engages the biliary lining, and ultrasound observation and iodine-doped polylactic acid markers are used to adjust positioning. The stent degrades within 6-12 months, eliminating the need for secondary surgical removal.

[0046] Example 3: Degradable Mechanically Embedded Biliary Stent; This example designs a degradable biliary stent that uses mechanically embedded anchoring protrusions 21 for flexible protrusion applications. The stent body 1 and anchoring protrusions 21 are made of polycaprolactone, with a diameter of 9 mm, a length of 70 mm, and a wall thickness of 0.3 mm. It is non-self-expanding. The positioning structure 2 includes eight anchoring protrusions 21 and four imaging markers 22. The anchoring protrusions 21 are made of polycaprolactone, 0.6 mm high, and have a Y-shaped cross-section with a bifurcation angle of 60 degrees. They are distributed in a circular pattern and secured by mechanical embedding.

[0047] Manufacturing method: Provide polycaprolactone particles and form a tubular billet through an extrusion molding device. The extrusion temperature is 170°C and the screw speed is 35 rpm.

[0048] The tubular blank was placed in a laser cutting device, and a laser power of 20 W and a cutting speed of 6 mm / s were used to prepare a mesh structure with a mesh size of 0.9×0.9 mm.

[0049] Provide polycaprolactone raw material, and prepare Y-shaped anchoring protrusions 21 with a snap-on structure by injection molding. The injection molding temperature is 160°C, the pressure is 55 MPa, and the molding time is 12 seconds. Prepare 8 anchoring protrusions 21.

[0050] Eight fitting grooves with a diameter of 0.8 mm and a depth of 0.5 mm were formed on the outer wall of the bracket by laser micromachining (power 18 W).

[0051] The buckle structure of the anchoring protrusion 21 is pressed into the fitting groove and locked by applying a 10N pressure through a mechanical pressing process.

[0052] Four iodine-doped polylactic acid developer marks 22 (iodine content 20 wt%) were embedded with a diameter of 1 mm and a spacing of 10 mm. Embedded grooves with a diameter of 1 mm and a depth of 0.4 mm were formed using a laser drilling device with a laser power of 18 W and a pulse frequency of 90 kHz. Developer particles were prepared by injection molding (170°C, 60 MPa, 12 seconds) and fixed by hot pressing (100°C, 6 N, 10 seconds).

[0053] A polyethylene glycol hydrophilic coating was applied to the stent surface to a thickness of 40 μm. The coating was applied at a power of 28 kW, a spray distance of 140 mm, and a spray time of 10 minutes. The stent was then heat-treated in a vacuum oven at 95°C for 30 minutes and then cured with UV light (wavelength 280 nm, 15 minutes).

[0054] The stent was finally ultrasonically cleaned for 5 minutes at a frequency of 40 kHz and sterilized by fumigation with ethylene oxide gas for 5 hours.

[0055] Usage: Preoperatively, the stenosis location is determined through X-ray or ultrasound examination. The stent is pushed to the target location through an endoscope. The Y-shaped anchoring protrusion 21 is embedded in the inner wall. X-ray observation and iodine-doped polylactic acid marker are used to confirm the positioning. The stent degrades in 6-12 months and does not need to be removed.

[0056] The above examples demonstrate the application of the present invention with various materials (nickel-titanium alloy, polylactic acid, polycaprolactone), fixation methods (integrated molding, mechanical interlocking), and designs (self-expanding, non-self-expanding). The Y-shaped anchoring protrusion 21, with its bifurcated structure, enhances fixation stability, increasing fixation force by 25-35%. Iodine-doped polylactic acid and gold ring-shaped imaging markers 22 ensure precise positioning, with a positioning deviation of less than 0.5-0.8 mm. Manufacturing methods include extrusion, laser cutting, injection molding, hot pressing, mechanical interlocking, plasma spraying, and sterilization. The parameters (e.g., injection molding at 160-200°C and hot pressing at 100-120°C) are optimized, making it suitable for mass production. The stent's positioning accuracy, fixation stability, and biocompatibility surpass those of conventional designs, making it suitable for the treatment of conditions such as biliary strictures and obstructions. Short-term implantation (degradable stents) requires no removal, while long-term implantation (metal stents) offers high stability. Antimicrobial and hydrophilic coatings reduce the risk of infection and inflammation, resulting in significant clinical efficacy.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A biliary stent with a positioning structure for hepatobiliary and pancreatic surgery, characterized in that: include: A stent body (1), the stent body (1) being a tubular structure suitable for implantation into the bile duct to maintain bile duct patency; A positioning structure (2) is provided on the support body (1), wherein the positioning structure (2) comprises at least one anchoring protrusion (21) and at least one developing mark (22); The anchoring protrusion (21) is provided on the outer wall of the stent body (1), and both the cross section and the vertical section of the anchoring protrusion (21) are Y-shaped, and is used to engage with the inner wall of the bile duct to enhance fixation stability; The development marker (22) is embedded in the stent body (1) and is used for development under X-ray or ultrasound imaging to assist intraoperative positioning.

2. A biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 1, characterized in that: The stent body (1) is made of a medical polymer material or a metal alloy. The medical polymer material includes polyurethane, polylactic acid or polycaprolactone, and the metal alloy includes nickel-titanium alloy.

3. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 1, characterized in that: The anchoring protrusions (21) are distributed in an annular shape on the outer wall of the stent body (1), with a number of 4-8. The height of the anchoring protrusions (21) is 0.3-0.8 mm, and the bifurcation angle of the Y-shaped cross section is 30-60 degrees.

4. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 3, characterized in that: The anchoring protrusion (21) is made of a degradable flexible material, wherein the degradable flexible material includes degradable polyurethane, polylactic acid or polycaprolactone. The anchoring protrusion (21) is integrally formed with the stent body (1) by the following manufacturing method: A degradable flexible material is provided, and an anchoring protrusion (21) having a Y-shaped cross section is prepared by an injection molding process, wherein the injection molding temperature is 160-200°C, the pressure is 50-80 MPa, and the molding time is 10-20 seconds; Performing plasma activation treatment at predetermined positions on the outer wall of the stent body (1) to enhance surface bonding strength; The anchoring protrusion (21) is combined with the stent body (1) by a hot pressing process, wherein the hot pressing temperature is 100-120°C, the pressure is 5-10N, and the time is 10-15 seconds to form an integrated structure; The one-piece molded bracket is ultrasonically cleaned for 3-5 minutes to remove surface residues.

5. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 1, characterized in that: The development marks (22) include iodine-doped polylactic acid, gold rings or tantalum particles. The number of the development marks (22) is 2-4, and they are spaced apart along the longitudinal direction of the stent body (1) at a spacing of 10-30 mm.

6. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 5, characterized in that: The imaging mark (22) is embedded in the stent body (1) by the following manufacturing method: A laser drilling device is used to form an embedding groove at a predetermined position of the bracket body (1), wherein the diameter of the embedding groove is 0.5-1 mm, the depth is 0.2-0.5 mm, the laser power is 10-20 W, and the pulse frequency is 50-100 kHz; For the iodine-doped polylactic acid developing mark (22), developing particles with a diameter of 0.5-1 mm are prepared by injection molding at an injection temperature of 160-180°C, a pressure of 50-70 MPa, and a molding time of 10-15 seconds. The developing particles are placed in the embedding groove and fixed by applying a pressure of 5-8 N by a hot pressing process at a hot pressing temperature of 100-110°C and a time of 10 seconds. For gold rings or tantalum dots, a mechanical pressing process is used to apply a pressure of 5-10N to fix them, followed by electroplating. The electroplating solution includes an electrolyte solution containing gold or tantalum, the current density is 0.5-1A / dm², and the electroplating time is 2-5 minutes. Ultrasonic cleaning of the embedded area was performed for 3-5 minutes to remove residual impurities.

7. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 1, characterized in that: The surface of the stent body (1) is coated with a hydrophilic coating or an antibacterial coating, wherein the hydrophilic coating comprises polyethylene glycol, and the antibacterial coating comprises a silver-containing nanomaterial.

8. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 7, characterized in that: The hydrophilic coating or antibacterial coating is applied to the stent body (1) by the following manufacturing method: Providing polyethylene glycol or silver-containing nanomaterials as coating materials, placing the stent body (1) in a plasma spraying device with a spraying power of 20-30kW and a spraying distance of 100-150mm; The coating material is deposited on the surface of the stent body (1) by a plasma spraying process, the coating thickness is controlled to be 10-50 μm, and the spraying time is 5-10 minutes; The coated stent body (1) is placed in a vacuum oven and heat treated at 80-100°C for 20-30 minutes; The coating surface is subjected to UV curing treatment, the UV wavelength is 250-300nm, and the curing time is 10-15 minutes.

9. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 3, characterized in that: The anchoring protrusion (21) is fixed to the stent body (1) by the following mechanical interlocking method: An interlocking groove is formed on the outer wall of the bracket body (1) by laser micromachining, wherein the diameter of the interlocking groove is 0.5-1 mm, the depth is 0.3-0.6 mm, and the laser power is 15-25 W; An anchoring protrusion (21) made of a degradable flexible material is provided, wherein the degradable flexible material includes degradable polyurethane, polylactic acid or polycaprolactone, and the anchoring protrusion (21) has a Y-shaped cross-section and a snap-fit ​​structure at the bottom, and is prepared by injection molding, with an injection molding temperature of 160-200°C, a pressure of 50-80MPa, and a molding time of 10-20 seconds; Pressing the buckle structure of the anchoring protrusion (21) into the fitting groove, applying a pressure of 8-12N through a mechanical pressing process, so that the anchoring protrusion (21) is locked to the bracket body (1); Ultrasonic cleaning of the mating area was performed for 3-5 minutes to remove processing residues.

10. The biliary stent with a positioning structure for hepatobiliary and pancreatic surgery according to claim 1, characterized in that: The stent body (1) and the anchoring protrusion (21) are made of a degradable material, wherein the degradable material includes polylactic acid or polycaprolactone. The developing mark (22) is made of iodine-doped polylactic acid, a gold ring or a tantalum particle. The stent body (1) and the anchoring protrusion (21) are prepared by the following manufacturing method: Placing polylactic acid or polycaprolactone particles in an extrusion molding device, controlling the extrusion temperature at 160-200°C and the screw speed at 30-50 rpm to form a tubular billet; The tubular blank is placed in a laser cutting device, using a laser power of 15-25 W and a cutting speed of 5-10 mm / s to prepare a stent body (1) having a mesh structure; A degradable flexible material is provided, and an anchoring protrusion (21) having a Y-shaped cross section is prepared by injection molding, wherein the injection molding temperature is 160-200°C, the pressure is 50-80 MPa, and the molding time is 10-20 seconds; Plasma activation treatment is performed at a predetermined position on the outer wall of the stent body (1), and the anchoring protrusion (21) is combined with the stent body (1) by a hot pressing process, with the hot pressing temperature being 100-120°C, the pressure being 5-10N, and the time being 10-15 seconds; Performing a final ultrasonic cleaning on the stent for 3-5 minutes to remove surface residues; The stent is sterilized by fumigation with ethylene oxide gas for 4-6 hours.

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