A gallbladder stone removal device

Abstract

This invention discloses a gallbladder stone removal device, comprising a mesh-like stent made of one or more interwoven braided filaments and a stent delivery system. The mesh-like stent includes a stent body and distal and proximal stent ends located at its two ends. When the mesh-like stent is in the released state, the diameter of the distal stent end is greater than or equal to the diameter of the stent body, and the diameter of the proximal stent end is greater than or equal to the diameter of the stent body. After the distal stent end of this invention is released, the stent diameter is greater than the inner diameter of the cystic duct and the common bile duct, forming a funnel-shaped structure that completely conforms to the bile duct wall. Combined with an external negative pressure suction device, gallstones in the gallbladder can be drawn into this funnel-shaped structure in one go and finally removed from the biliary system, eliminating the need for multiple insertions and removals of the gallbladder using a stone retrieval basket, thus avoiding damage to the gallbladder and bile ducts. The stent made of biodegradable filaments completely degrades within three months in the biliary system, eliminating the need for secondary surgery and avoiding complications.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a gallbladder stone removal device. Background Technology

[0002] See appendix Figure 1 As shown, the gallbladder is located below the liver. A normal gallbladder is about 8-12 cm long, 3-5 cm wide, and has a capacity of about 30-60 ml. The cystic duct is a slender tube connecting the gallbladder and the common bile duct. It is about 3-5 cm long and has an inner diameter of about 3-4 mm. Its main function is to transport bile stored in the gallbladder to the common bile duct and then into the intestines to participate in digestion.

[0003] See appendix Figure 2 As shown, gallstones are stones that form within the gallbladder, primarily caused by changes in the composition of bile and bile stasis. Gallstones are a common condition that can lead to a series of complications, with common symptoms including right upper quadrant pain and bloating. Most patients can relieve pain with medication, but when stones exceed 2 cm, the gallbladder wall is calcified, or stones are accompanied by gallbladder polyps, surgical removal of the gallbladder is necessary to alleviate symptoms, improve quality of life, and prevent future gallbladder cancer due to chronic inflammation. Gallbladder removal surgery has disadvantages such as significant trauma and slow postoperative recovery. Because the gallbladder is a vital digestive and immune organ, gallbladder removal can cause many side effects, such as indigestion, diarrhea, bloating, bile reflux gastritis, common bile duct stone formation, and even a significant increase in the risk of colon cancer. Theoretically, gallbladder-preserving stone removal is the optimal clinical treatment for gallstones. Extracorporeal shock wave lithotripsy (ESWL) or laser lithotripsy not only damages the gallbladder but also requires repeated lithotripsy of the same area, often leading to adhesions between the stones and surrounding tissues, ultimately requiring surgical intervention. Given the gallbladder's contractile function, establishing a temporary passage between the gallbladder and common bile duct can potentially clear small gallstones within a month. However, this temporary passage should not be maintained for extended periods, as reflux from the intestines and common bile duct can cause gallbladder infection and inflammation. In summary, a perfect gallbladder stone removal system requires: 1) an instrument capable of minimally invasive access to the gallbladder; 2) a device for minimally invasive and efficient removal of gallstones; and 3) a temporary passage between the gallbladder and common bile duct.

[0004] Patent documents “CN206714791U” and “CN113384346A” respectively disclose a forceps for laparoscopic gallstone removal and a cannula for laparoscopic gallbladder-preserving lithotripsy. During use, a special device is first used to crush large gallstones, and then the crushed stones are removed, thus completing the gallstone removal operation. However, this type of device has the following drawbacks: 1. It requires multiple removals of the forceps holding the stones from the gallbladder, which can easily damage the gallbladder and increase patient suffering; 2. During the crushing of large stones, small stone fragments fall into the gallbladder, requiring subsequent surgery to remove them.

[0005] Based on the above clinical pain points, a highly efficient gallbladder stone removal device was designed to solve the above problems.

[0006] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention aims to provide a gallbladder stone removal device.

[0008] To achieve the above and other related objectives, the technical solution provided by this invention is: a gallbladder stone removal device, comprising a tubular stent made of one or more interwoven braided filaments; the tubular stent includes a stent body and distal and proximal stent ends located at both ends thereof; when the tubular stent is in the released state, the diameters at both ends of the stent are greater than or equal to the diameter of the stent body. When the braided filaments are made of biodegradable materials, the tubular stent can be completely absorbed after completing its clinical function. It should be noted that the term "multiple filaments" in this solution includes two filaments.

[0009] Furthermore, the distal end of the stent is released into the gallbladder in a funnel-shaped or crown-shaped structure, while the proximal end of the stent is released into the common bile duct or duodenum in a straight tube-shaped or crown-shaped structure. It should be noted that the shape of the stent in its proximal release state includes, but is not limited to, a straight tube-shaped or crown-shaped structure, and can also be drum-shaped or other shapes that meet functional requirements.

[0010] It should be noted that the funnel shape in this design refers to a woven mesh structure formed by the diameter gradually increasing from the distal end of the support away from the main body. The spherical crown shape in this design refers to a large spherical crown shape containing a center. The drum shape in this design refers to a drum-like profile formed by the largest diameter at the middle of the proximal end of the support, gradually narrowing towards both ends along its axis.

[0011] Furthermore, during weaving, the braiding filaments interweave / interweave back and forth in a helical feeding manner along the axial direction.

[0012] Furthermore, when the number of braided filaments is greater than or equal to two, the braided filaments at both ends of the tubular stent are either unconnected open structures or closed structures fixed in pairs. It should be noted that in the closed structure, the braided filaments are fixed in pairs by means including but not limited to welding, riveting, crimping, and bonding (using medical-grade biocompatible adhesives), or other fixing methods that meet the functional requirements of the stent.

[0013] In the open structure, the ends of the braided wires are unconnected. The advantage of this structure is low processing cost, but the mechanical properties of the two ends of the mesh-like support are inconsistent and it is easy to become loose. In the closed structure, the ends of the braided wires are fixed by welding or riveting. The advantage of this structure is that the mechanical properties of the two ends of the mesh-like support are stable, but the processing cost is high.

[0014] Furthermore, the materials of the braided filaments include, but are not limited to, magnesium alloys, iron (based) alloys, zinc alloys, molybdenum alloys, nickel-titanium alloys, cobalt-chromium alloys, polyglycolic acid, polylactic acid, polyglycolic acid-lactide, or polycaprolactone. In specific embodiments, the biodegradable metal wires are made of, but are not limited to, magnesium alloys, iron alloys, zinc alloys, or molybdenum alloys.

[0015] Furthermore, the surface of the tubular stent is provided with a polymer film layer, which at least covers the distal portion of the tubular stent along its axial direction; in the released state, the tubular stent can form a closed, aspirable lumen structure that completely conforms to the bile duct wall. The material of the polymer film layer includes, but is not limited to, polyglycolic acid, polylactic acid, polyglycolic acid-lactide, polycaprolactone, silicone, or polyurethane.

[0016] Furthermore, the tubular scaffold and / or polymer film layer are loaded with drugs. The scaffold surface and polymer film layer may be loaded with therapeutic drugs, for example, antibiotics, antiplatelet drugs, anti-inflammatory drugs, drugs that promote endothelialization, or anti-tissue proliferation drugs.

[0017] Furthermore, the diameter of the braided filament is 0.05~0.5mm; the length of the tubular support in the released state is 20~200mm, and the support diameter is 3~20mm. In a specific embodiment, the surface of the biodegradable metal wire can be passivated as required.

[0018] Furthermore, the cross-sectional shape of the braided yarn is at least one of circular, elliptical, and rectangular. The cross-sectional shape of the braided yarn includes, but is not limited to, one or more combinations of circular, elliptical, and rectangular shapes.

[0019] Furthermore, the present invention also includes a stent delivery system for delivering the mesh-like stent: the stent delivery system includes an inner tube and an outer tube disposed inside and outside the inner tube and the outer tube defining a receiving cavity for compressing and receiving the mesh-like stent;

[0020] The inner tube has a handle at its proximal end and a flexible head extending out of the accommodating cavity at its distal end. The inner tube has a bracket retraction buckle at the end near the flexible head, and the proximal end of the outer tube is connected to the handle.

[0021] As the outer tube moves toward the handle, the mesh-like support gradually protrudes from the receiving cavity and is released, and the inner diameter of the mesh-like support after release is greater than the outer diameter of the outer tube.

[0022] It is important to note that the proximal end refers to the end that enters the body and is close to the handle along the direction in which the stent is implanted, while the distal end refers to the end that enters the body first and is close to the soft tip of the delivery system along the direction in which the stent is implanted.

[0023] Furthermore, the outer tube is composed of an outer layer, a middle layer, and an inner layer sequentially nested from the outside in. The middle layer is a mesh-like structure or a spring structure made of woven metal wire. The material hardness of the distal end of the outer tube is less than or equal to the material hardness of the outer tube body. The inner diameter of the outer tube is 1~7mm, and the outer diameter of the outer tube is 2~10mm.

[0024] Due to the application of the above technical solution, the beneficial effects of this invention compared with the prior art are as follows:

[0025] Compared with clinically used devices and published invention applications, the gallbladder stone removal device of the present invention has the following advantages:

[0026] (1) The distal end of the stent delivery system of the present invention is relatively soft and has good flexural strength, which can enter the tortuous cystic duct and avoid excessive expansion and damage to the cystic duct.

[0027] (2) After the distal end of the stent of the present invention is released, the stent diameter is larger than the inner diameter of the cystic duct, which can form a structure that fits completely with the bile duct wall. Combined with the external negative pressure suction device, the gallstones in the gallbladder can be sucked into the structure in one go and finally removed from the biliary system. There is no need to use the traditional stone retrieval basket to enter and exit the gallbladder multiple times, thus avoiding damage to the gallbladder and bile duct.

[0028] (3) The diameters at both ends of the bracket of the present invention are larger than the diameter of the bracket body, so the bracket will not shift.

[0029] (4) The stent made of biodegradable material used in this invention can be completely degraded in the biliary system in about three months, without the need for a second surgery to remove it. This not only reduces the cost of surgery, but also avoids serious complications such as cholangitis and pancreatitis. Attached Figure Description

[0030] Figure 1 A schematic diagram of the anatomy of the gallbladder, bile duct, and duodenum;

[0031] Figure 2 This is a schematic diagram of gallstones.

[0032] Figure 3 This is a schematic diagram of the gallbladder stone removal stent of the present invention (the diameters of both the distal and proximal ends are larger than the diameter of the main body).

[0033] Figure 4 This is a schematic diagram of the support conveying system of the present invention;

[0034] Figure 5 This is a schematic diagram of the inner tube and related structures of the present invention;

[0035] Figure 6 This is a schematic diagram of the outer tube structure of the present invention;

[0036] Figure 7 This is a schematic diagram showing the removal of gallstones from the gallbladder via an external aspiration pump after the distal end of the stent of the present invention has been deployed.

[0037] Figure 8 This is a schematic diagram of the gallbladder stone removal stent of the present invention (both the distal and proximal ends are spherical).

[0038] Figure 9 This is a schematic diagram of the gallbladder stone removal stent of the present invention (the distal diameter is larger than the main body diameter);

[0039] Figure 10 This is a schematic diagram of the gallbladder stone removal stent of the present invention being placed as a temporary stent in the cystic duct;

[0040] In the above attached diagrams, 1. distal end of the stent; 2. stent body; 3. proximal end of the stent; 4. outer tube; 5. inner tube; 6. stent retrieval buckle; 7. soft head; 8. handle; 9. inner layer; 10. intermediate layer; 11. outer layer. Detailed Implementation

[0041] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0044] See appendix Figure 3 Appendix Figure 8 and attached Figure 9 As shown, the gallbladder stone removal device of the present invention includes a tubular stent, which is a tubular stent made of one or more biodegradable braided filaments. The tubular stent includes a stent body 2 and a distal stent 1 and a proximal stent 3 located at both ends thereon. When the tubular stent is in the released state, the diameter of the distal stent 1 is greater than or equal to the diameter of the stent body 2, and the diameter of the proximal stent 3 is greater than or equal to the diameter of the stent body 2. The braided filaments are made of biodegradable material, and the tubular stent can be completely absorbed after clinical function is completed. The distal stent 1 has a funnel-shaped or crown-shaped structure in the released state, and the proximal stent 3 has a straight tube-shaped, crown-shaped, or drum-shaped structure in the released state.

[0045] It should be noted that, in this embodiment, "straight tubular" refers to a tubular structure with the same diameter as the stent body 2. "Funnel-shaped" refers to a woven mesh structure formed by the diameter of the distal end 1 of the stent gradually increasing away from the stent body 2. "Crown-shaped" refers to a large spherical shape containing a center. "Drum-shaped" refers to a drum-like outline formed by the largest diameter at the middle of the proximal end 3 of the stent, gradually narrowing towards both ends along its axial direction. In specific embodiments, the shape of the distal end 1 of the stent in the stent-released state is not limited to funnel-shaped or crown-shaped, and the shape of the proximal end 3 of the stent in the stent-released state is not limited to straight tubular, crown-shaped, or drum-shaped.

[0046] During weaving, the braided filaments interweave / reciprocate in a helical feed along the axial direction. It is important to note that when the braided filaments of the same diameter are fed at a constant pitch during interweaving, this ensures uniform expansion of the mesh openings in that section, improving support stability and resulting in more stable overall support within the bile duct. When there are two or more braided filaments, the braided filaments at both ends of the tubular support are either unconnected open structures or closed structures fixed by welding or riveting in pairs. In the open structure, the ends of the braided filaments are unconnected. The advantage of this structure is low processing cost, but the mechanical properties at both ends of the tubular support may deviate, making it prone to loosening. See Appendix. Figure 3 As shown, in the closed structure, the ends of the braided wires are in a welded and fixed state. The advantage of this structure is that the mechanical properties of both ends of the mesh tube support are stable, but the processing cost is high.

[0047] Based on this, in some embodiments, the material of the braided filaments includes, but is not limited to, biodegradable metals such as magnesium alloys, iron (based) alloys, zinc alloys, or molybdenum alloys.

[0048] In some embodiments, the surface of the tubular stent is provided with a polymer film layer. The material of the polymer film layer includes, but is not limited to, polyglycolic acid, polylactic acid, polyglycolic acid-lactide, polycaprolactone, silicone, or polyurethane. It should be noted that the polymer film layer on the surface of the tubular stent covers at least the distal portion axially. In specific embodiments, the polymer film layer on the surface of the tubular stent may cover the following axially: the distal end of the stent, the distal end of the stent plus part of the stent body, the distal end of the stent plus the stent body, the distal end of the stent plus the stent body plus part of the proximal end of the stent, or the distal end of the stent plus the stent body plus the proximal end of the stent (i.e., the entire axial length of the stent). The membrane-coated tubular stent, in its deployed state, forms a completely sealed, aspirable lumen structure that adheres perfectly to the bile duct wall.

[0049] The tubular scaffold and / or polymer film layer are loaded with drugs. The scaffold surface and polymer film layer may be loaded with therapeutic drugs, for example, antibiotics, antiplatelet drugs, anti-inflammatory drugs, drugs that promote endothelialization, or anti-tissue proliferation drugs, such as rapamycin, paclitaxel, cilostazol, ticlopidine, tripterygium wilfordii, and dexamethasone. In some embodiments, the diameter of the braided filaments is 0.05~0.5mm; in specific embodiments, the diameter of the braided filaments may be 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm. The surface of the biodegradable metal wires may be passivated according to specific clinical requirements. After passivation, a dense protective film can be formed, which can delay degradation. The length of the tubular scaffold is 20~200mm; in specific embodiments, the length of the tubular scaffold may be 20mm, 50mm, 100mm, 120mm, 150mm, or 200mm. The diameter of the tubular support in the released state is 3-20 mm; in specific embodiments, the diameter of the tubular support in the released state can be 3 mm, 5 mm, 8 mm, 12 mm, 16 mm, or 20 mm. The cross-sectional shape of the braided filaments is at least one of circular, elliptical, and rectangular. In specific embodiments, the cross-sectional shape of the braided filaments includes, but is not limited to, one or more combinations of circular, elliptical, and rectangular shapes.

[0050] To facilitate the successful implantation of the tubular stent into the lesion site, this invention also proposes a stent delivery system, see attached document. Figure 4 and attached Figure 5 As shown, the stent delivery system includes an inner tube 5 and an outer tube 4, which are separated by an inner tube 5 and an outer tube 4. The inner tube 5 and the outer tube 4 define a receiving cavity for compressing and storing the mesh-like stent. A handle 8 is provided at the proximal end of the inner tube 5, and a flexible head 7 is provided at the distal end of the inner tube 5, extending out of the receiving cavity. A stent retrieval buckle 6 is provided at the end of the inner tube 5 near the flexible head 7. The proximal end of the outer tube 4 is connected to the handle 8. When the outer tube 4 moves towards the handle 8, the mesh-like stent gradually protrudes out of the receiving cavity and is released. The inner diameter of the mesh-like stent after release is larger than the outer diameter of the outer tube 4.

[0051] See appendix Figure 6As shown, the outer tube 4 is composed of an outer layer 11, a middle layer 10, and an inner layer 9, which are sequentially nested from the outside in. The outer tube 4 has a three-layer composite structure: outer layer 11 (contact tissue), middle layer 10 (reinforcing layer), and inner layer 9 (sliding layer). The middle layer 10 is a mesh-like structure or a spring structure made of woven metal wires. The material hardness of the distal end of the outer tube 4 is less than or equal to the material hardness of the main body of the outer tube 4. The inner diameter of the outer tube 4 is 1~7mm. In specific embodiments, the inner diameter of the outer tube 4 can be 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, or 7mm. The outer diameter of the outer tube 4 is 2~10mm. In specific embodiments, the outer diameter of the outer tube 4 can be 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, or 10mm.

[0052] It should be noted that, in some embodiments, the material of the inner layer 9 includes, but is not limited to, polytetrafluoroethylene and high-density polyethylene; the material of the metal wires braiding the middle layer 10 includes, but is not limited to, stainless steel, nickel-titanium shape memory alloy and cobalt-chromium alloy; the material of the outer layer 11 includes, but is not limited to, polyurethane, nylon or modified nylon PEBAX. In some specific embodiments, the outer layer 11 can be made of more than one material (non-chemical mixing), such as using two materials to make a section and then splicing them together, thereby achieving different hardness at the far and near ends;

[0053] The outer layer 11 material at the distal end of the outer tube 4 has a Shore hardness of 40A to 50A (A scale), the main body of the outer tube 4 has a Shore hardness of 90A to 40D, and the proximal end of the outer tube 4 has a Shore hardness of 50D to 85D (D scale). Where 90A ≈ 38D, 40D ≈ 90A (referencing ASTM D2240 standard). The distal end of the outer tube 4 uses a soft Shore 40A–50A material to ensure flexibility through tortuous bile ducts; the proximal end uses a hard Shore 50D–85D material to ensure thrust transmission; and the main body of the outer tube 4 uses a hard Shore 38D–40D material to achieve a stiffness transition (referencing ASTM D2240 standard).

[0054] This invention relates to a biliary stent and its delivery system, constructed from biodegradable metal wires with diameters at both ends larger than the main body diameter. Even after deployment of no more than 90% of the stent's total length, it can still be retrieved into the delivery system. The distal end 1 or the entire length of the stent can be covered with a biodegradable polymer membrane. When only the distal end of the stent is deployed, it forms a funnel-shaped structure that completely conforms to the bile duct wall. Combined with an external negative pressure suction device or needle, gallstones in the gallbladder can be drawn into the funnel-shaped structure in one go. The stones can then be removed from the gallbladder and biliary system by withdrawing the delivery system. The device can also remove bile duct stones, including those in the common bile duct. After the gallbladder and bile duct stones are removed, the distal end of the stent delivery system carrying the biliary stent is placed into the gallbladder. The distal end 1 of the stent is released into the gallbladder, the main body 2 into the cystic duct, and the proximal end 3 into the common bile duct, forming a temporary channel from the gallbladder to the common bile duct. Depending on clinical needs, a longer biliary stent can be deployed with its distal end 1 in the gallbladder, its main body 2 in the common bile duct, and its proximal end 3 in the junction of the duodenum and bile duct, forming a temporary channel from the gallbladder to the duodenum. This facilitates the emptying of residual stones from the gallbladder and biliary system into the duodenum. The biodegradable fibers and biodegradable membrane that make up the biliary stent will completely degrade within three months of placement, eliminating the need for a second surgery to remove the stent.

[0055] Example 1:

[0056] See appendix Figure 3 As shown, in this embodiment, the number of braided filaments is 24; the diameter of the braided filaments is 0.05 mm; the surface treatment of the braided filaments is passivation; the material of the braided filaments is magnesium alloy; the diameter of the distal end 1 of the support is 12 mm, the diameter of the main body 2 of the support is 8 mm, the diameter of the proximal end 3 of the support is 8 mm, and the braided filaments at both ends of the support are fixed by welding in pairs; the surface coating of the support is: the distal end 1 of the support is covered with a biodegradable polymer film. The shape of the distal end 1 of the support is drum-shaped; the shape of the proximal end 3 of the support is crown-shaped.

[0057] After passivation treatment, a dense protective film forms on the surface of magnesium alloy wire, which helps to delay degradation.

[0058] See appendix Figure 4 As shown, the support delivery system of this invention includes an outer tube 4, an inner tube 5, a support retrieval buckle 6, a flexible head 7, and a handle 8. The outer tube 4 is a composite structure tube with an inner diameter of 2.5 mm, an outer diameter of 3.5 mm, a flexible distal end, high rigidity in the main body, and high rigidity in the proximal end.

[0059] See appendix Figure 5As shown, the outer tube 4 of the stent delivery system has a three-layer structure: from the outside to the inside, it includes an outer layer 11, a middle layer 10, and an inner layer 9. The inner layer 9 is made of polytetrafluoroethylene (PTFE), which makes the surface of the inner layer 9 very smooth, facilitating relative sliding with the inner tube 5. The middle layer 10 is a braided mesh structure made of stainless steel wire. The outer layer 11 is made of PEBAX with a Shore hardness of 35D, 45D, 55D, 63D, and 72D, and 85D nylon, respectively, from distal to proximal. The structure provides good flexibility at the distal end of the catheter, allowing it to enter the gallbladder even without using a high-pressure dilation balloon to dilate the cystic duct.

[0060] First, the doctor, using a digestive endoscope and its auxiliary instruments, pushes a guidewire into the cystic duct. After withdrawing the endoscope, the distal end of the stent delivery system in this embodiment is pushed into the gallbladder. The doctor holds the handle 8 of the stent delivery system with one hand and slowly retracts the outer tube 4 of the stent delivery system with the other hand, releasing the distal end 1 of the stent in this embodiment. The stent body 2 and the proximal end 3 remain inside the outer tube 4 of the stent delivery system (the body and proximal end are still constrained within the outer tube 4), forming an appendage. Figure 7 The funnel-shaped structure shown (funnel-shaped suction chamber) can be used in conjunction with an external negative pressure suction device (such as a suction pump) to aspirate gallstones into the funnel-shaped structure formed by the distal end 1 of the stent in one go. At this time, the stent delivery system is slowly withdrawn, and the gallstones can be removed from the gallbladder and bile duct, and finally released into the duodenum, where they can be excreted from the body through the intestines.

[0061] If a stent is clinically required to be placed in the patient's gallbladder and bile duct, after the doctor removes various gallstones, the distal end of the stent delivery system is pushed into the gallbladder. The doctor holds the handle 8 of the stent delivery system with one hand and slowly retracts the outer tube 4 of the stent delivery system with the other, gradually releasing the distal end 1 of the stent (in this embodiment) into the gallbladder, the stent body 2 into the common bile duct, and the proximal end 3 into the junction of the duodenum and common bile duct, forming a temporary channel from the gallbladder to the duodenum, facilitating the emptying of residual stones from the gallbladder and biliary system into the duodenum. In this embodiment, the diameter of the distal end 1 of the stent is larger than the diameter of the stent body 2, preventing the stent from shifting out of the gallbladder. After the stent is placed in the gallbladder and bile duct, the biodegradable membrane of the distal end 1 and the biodegradable filaments constituting the stent gradually begin to degrade. The entire biliary stent is degraded in about three months, avoiding a second surgery to replace the stent.

[0062] Example 2:

[0063] See appendix Figure 8As shown, in this embodiment, the number of braided filaments is 16; the filament diameter is 0.1mm; the filament surface treatment is none; the braided filament material is molybdenum alloy; the diameter of the distal end 1 of the bracket is 15mm, the diameter of the main body 2 of the bracket is 10mm; the diameter of the proximal end 3 of the bracket is 15mm; the state between the braided filaments at both ends of the bracket is that they are fixed by welding in pairs; the surface coating of the bracket is none.

[0064] The shape of the distal end 1 of the stent is spherical; the shape of the proximal end 3 of the stent is spherical.

[0065] For patients without large gallstones, the non-covered access stent of this embodiment can be used. In this embodiment, the outer tube 4 is used as a catheter, which is a large-diameter catheter with an inner diameter of 3 mm, an outer diameter of 4 mm, and a flexible distal end. Its inner layer 9 is made of polytetrafluoroethylene, which makes the surface of the inner layer 9 very smooth. The middle layer 10 is a spring mesh structure woven from stainless steel wire. The material of the outer layer 11 is PEBAX with a Shore hardness of 35D, 45D, 55D, 63D, and 75D nylon, which are successively from distal to proximal.

[0066] After the doctor breaks the gallstones in the gallbladder into smaller pieces using a traditional method (in vivo or extracorporeal lithotripsy), the distal end of the stent delivery system (excluding the stent) is pushed into the gallbladder along a guidewire. The handle (8) at the proximal end of the catheter is connected to a negative pressure suction device, which can aspirate the small gallstone fragments into the lumen of the stent delivery catheter in one go. Then, the catheter is withdrawn from the patient's body, and compressed air is used to blow out the stones from the lumen of the stent delivery catheter. Finally, a procedure similar to that in Example 1 can be used, where the distal end (1) of the stent in this example is released into the gallbladder, the stent body (2) is released into the common bile duct, and the proximal end (3) of the stent is released at the junction of the duodenum and the common bile duct, forming a temporary channel from the gallbladder to the duodenum, facilitating the emptying of residual stones from the gallbladder and biliary system into the duodenum. After the stent is placed in the gallbladder and bile duct, the biodegradable wire gradually begins to degrade, and it is completely degraded in about three months, avoiding a second surgery to replace the stent.

[0067] Example 3:

[0068] The device in this embodiment may not contain a stent and is suitable for patients with small and few gallstones in the gallbladder.

[0069] In this embodiment, the stent delivery tube 4 serves as a gallbladder stone aspiration tube. It is a large-diameter catheter with an inner diameter of 4 mm, an outer diameter of 5 mm, and a flexible distal end. The inner layer 9 is made of polytetrafluoroethylene (PTFE), which makes the surface of the inner layer 9 very smooth. The middle layer 10 is a braided mesh structure made of stainless steel wire. The outer layer 11 is made of PEBAX with a Shore hardness of 35D, 45D, 55D, and 63D, and 75D nylon, respectively, from distal to proximal.

[0070] The doctor first inserts a guidewire into the gallbladder using a traditional method. Following the guidewire, the distal end of the stone aspiration tube (outer tube 4) in this embodiment is pushed into the gallbladder. The proximal handle 8 of the stone aspiration tube is connected to a negative pressure suction device, which can aspirate small gallstones from the gallbladder into the tube's lumen in one go. While withdrawing the stone aspiration tube, the doctor continues to use the external negative pressure suction device to gradually draw stones from the bile duct (common bile duct) into the tube. Finally, the stone aspiration tube is withdrawn from the patient's body, thus efficiently and minimally invasively removing gallstones and bile duct stones.

[0071] Example 4:

[0072] See appendix Figure 8 As shown, in this embodiment, the number of braided filaments is 1; the surface treatment of the braided filaments is none; the material of the metal wire is zinc alloy; the diameter of the distal end 1 of the support is 15mm; the diameter of the main body 2 of the support is 10mm; the diameter of the proximal end 3 of the support is 15mm; the surface coating of the support is a biodegradable polymer film covering the entire length of the support.

[0073] The shape of the distal end 1 of the stent is spherical; the shape of the proximal end 3 of the stent is spherical.

[0074] In this embodiment, the outer tube 4 of the stent delivery system is a conduit with an inner diameter of 2 mm and an outer diameter of 3 mm; the inner layer 9 is made of polytetrafluoroethylene, which makes the surface of the inner layer 9 very smooth; the middle layer 10 is a braided mesh structure made of nickel-titanium alloy wire; for removing stones from the common bile duct, the outer tube 4 does not need a soft distal end. In this embodiment, the material of the outer tube 4 from distal end to proximal end is PEBAX with a Shore hardness of 63D, PEBAX with a Shore hardness of 72D, and nylon with a hardness of 85D.

[0075] First, the doctor, using a digestive endoscope and its auxiliary instruments, pushes a guidewire into the common bile duct. After withdrawing the endoscope, the distal end of the stent delivery system in this embodiment is pushed into the proximal end of the stone within the common bile duct. The doctor holds the handle 8 of the stent delivery system with one hand and slowly retracts the outer tube 4 of the stent delivery system with the other hand, releasing the distal end 1 of the stent in this embodiment. The stent body 2 and the proximal end 3 remain inside the outer tube 4 of the stent delivery system, forming a funnel-shaped structure that completely conforms to the bile duct wall. Combined with an external negative pressure suction device, the bile duct stone can be suctioned into the funnel-shaped structure formed by the distal end 1 of the stent in one go. At this time, the stent delivery system is slowly retracted, and the stone is removed from the bile duct and finally released into the duodenum, allowing the gallstone to be expelled from the body through the intestines. Finally, a similar operation method to that in Embodiment 1 can be used to gradually release the distal end 1 and the stent body 2 into the common bile duct and the proximal end 3 into the duodenum, forming a temporary channel from the common bile duct to the duodenum, facilitating the emptying of any remaining stones in the entire biliary system. In this embodiment, the diameter of the distal end 1 of the stent is larger than the diameter of the stent body 2, preventing the stent from shifting out of the gallbladder. After the biliary stent is placed in the common bile duct, the distal biodegradable membrane and the biodegradable filaments constituting the stent gradually begin to degrade. The entire stent is degraded in about three months, avoiding the need for a second surgery to replace the stent.

[0076] Example 5:

[0077] See appendix Figure 9 As shown, in this embodiment, the number of braided filaments is 1; the surface treatment of the braided filaments is none; the material of the metal wires is iron-based alloy; the diameter of the distal end 1 of the support is 15mm; the diameter of the main body 2 of the support is 10mm; the diameter of the proximal end 3 of the support is 15mm; the state between the filaments at both ends of the support is naturally formed in a closed state; the surface coating of the support is: the distal end of the support is covered with a biodegradable polymer film.

[0078] The shape of the distal end 1 of the stent is spherical; the shape of the proximal end 3 of the stent is straight tubular.

[0079] In this embodiment, the outer tube 4 of the stent delivery system is a conduit with an inner diameter of 2 mm and an outer diameter of 3 mm. The inner layer 9 of the outer tube 4 is made of polytetrafluoroethylene (PTFE), which makes the surface of the inner layer 9 very smooth. The middle layer 10 of the outer tube 4 is a braided mesh structure made of nickel-titanium alloy wire. The outer layer 11 of the outer tube 4 is made of PEBAX with a Shore hardness of 35D, 45D, 55D, 63D, 72D, and 85D nylon, which are successively made from the distal end to the proximal end.

[0080] First, the doctor, using a digestive endoscope and its auxiliary instruments, pushes a guidewire into the cystic duct. After withdrawing the endoscope, the distal end of the stent delivery system in this embodiment is pushed into the gallbladder. The doctor holds the handle 8 of the stent delivery system with one hand and slowly withdraws the outer tube 4 of the stent delivery system with the other hand, releasing the distal end 1 of the stent in this embodiment. The stent body 2 and the proximal end 3 remain in the outer tube 4 of the stent delivery system, forming a funnel-shaped structure. Combined with an external negative pressure suction device, gallstones in the gallbladder can be suctioned into the funnel-shaped structure formed by the distal end 1 of the stent in one go. At this time, the stent delivery system is slowly withdrawn, and the gallstones in the gallbladder are removed from the gallbladder and bile duct, and finally released into the duodenum, where they can be excreted from the body through the intestines. Finally, a similar operation method to that in Embodiment 1 can be used to gradually release the distal end 1 of the stent in the gallbladder, the stent body 2 into the cystic duct, and the proximal end 3 into the common bile duct, as shown in the example. Figure 10 As shown, a temporary channel is formed from the gallbladder to the common bile duct, facilitating the emptying of residual stones from the gallbladder. In this embodiment, the diameter of the distal end 1 of the stent is larger than the diameter of the stent body 2, preventing the stent from shifting out of the gallbladder. After the stent is placed in the gallbladder and bile duct, the distal biodegradable membrane and the biodegradable filaments constituting the stent gradually begin to degrade. The entire stent is degraded in about three months, avoiding the need for a second surgery to replace the stent.

[0081] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A gallbladder stone removal device, characterized in that: It includes a mesh-like support made of one or more interwoven braided filaments, wherein the braided filaments are made of a biodegradable material; The tubular stent includes a stent body (2) and stent distal end (1) and stent proximal end (3) located at both ends thereon; when the tubular stent is in the released state, the diameter of the stent distal end (1) is greater than the diameter of the stent body (2), and the diameter of the stent proximal end (3) is greater than or equal to the diameter of the stent body (2). The distal end (1) of the stent is released into the gallbladder in a spherical crown-like structure, and the proximal end (3) of the stent is released into the common bile duct or the duodenum in a straight tube-like or spherical crown-like structure; The surface of the tubular stent is provided with a polymer film layer, which at least covers the distal portion of the tubular stent in the axial direction; when the tubular stent is released, it can form a closed, aspirable lumen structure that is completely fitted to the bile duct wall. The device also includes a support delivery system for delivering the tubular support; The stent delivery system includes an inner tube (5) and an outer tube (4) with inner and outer sleeves, and the inner tube (5) and the outer tube (4) define a receiving cavity for compressing and receiving the mesh-like stent; The inner tube (5) has a handle (8) at its proximal end and a soft head (7) extending out of the accommodating cavity at its distal end. The inner tube (5) has a bracket retraction buckle (6) at one end near the soft head (7). The proximal end of the outer tube (4) is connected to the handle (8). When the outer tube (4) moves toward the handle (8), the mesh tube support gradually protrudes from the receiving cavity and is released, and the inner diameter of the mesh tube support after release is greater than the outer diameter of the outer tube (4).

2. The gallbladder stone removal device according to claim 1, characterized in that: During weaving, the braided filaments interweave / interweave back and forth in a spiral feeding manner along the axial direction; when the number of braided filaments is greater than or equal to two, the braided filaments located at both ends of the mesh-like support form an unconnected open structure or a closed structure fixed in pairs.

3. The gallbladder stone removal device according to claim 1, characterized in that: The braided yarn is made of magnesium alloy, iron alloy, zinc alloy, molybdenum alloy, polyglycolic acid, polylactic acid, polyglycolic acid-lactide, or polycaprolactone.

4. The gallbladder stone removal device according to claim 1, characterized in that: The polymer film layer is made of polyglycolic acid, polylactic acid, polyglycolic acid-lactide, polycaprolactone, silicone, or polyurethane.

5. The gallbladder stone removal device according to claim 4, characterized in that: The tubular scaffold and / or polymer film layer are loaded with drugs.

6. The gallbladder stone removal device according to claim 1, characterized in that: The diameter of the braided filament is 0.05~0.5mm; the length of the tubular support in the released state is 20~200mm and the diameter is 3~20mm.

7. The gallbladder stone removal device according to claim 1, characterized in that: The cross-sectional shape of the braided yarn is at least one of circular, elliptical, and rectangular.

8. The gallbladder stone removal device according to claim 1, characterized in that: The outer tube (4) is composed of an outer layer (11), a middle layer (10) and an inner layer (9) sequentially arranged from the outside to the inside. The middle layer (10) is a mesh structure or a spring structure made of woven metal wire. The material hardness of the distal end of the outer tube (4) is less than or equal to the material hardness of the main body of the outer tube (4). The inner diameter of the outer tube (4) is 1~7mm, and the outer diameter of the outer tube (4) is 2~10mm.

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