Pancreatic pseudocyst drainage stent, stent system and using method thereof

Abstract

The invention discloses a pancreatic pseudocyst drainage stent, a stent system and a using method thereof, the pancreatic pseudocyst drainage stent comprises a stent main body and an air bag part, the stent main body is a latticed stent formed by weaving medical memory metal, and the stent main body is in a straight tube shape; a recovery line is arranged on the near end side of the stent body and provided with a line knot. The air bag part comprises a far-end air bag, a near-end air bag, a covering film, an air channel, an air conveying pipe and an inflation one-way valve. The far-end air bag and the near-end air bag are arranged on the far-end side and the near-end side of the stent body respectively, the covering film is arranged between the far-end air bag and the near-end air bag, and the far-end air bag, the near-end air bag and the covering film jointly wrap the whole periphery of the stent body. The far-end air bag is communicated with the near-end air bag through the air passage; one end of the air delivery pipe is communicated with the near-end air bag, the other end of the air delivery pipe is separably communicated with the air inflation pipe part of the conveyor through the air inflation one-way valve so as to receive air injected from the outside, and the far-end air bag and the near-end air bag can be filled under the action of the air.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a pancreatic pseudocyst drainage stent, a stent system and a use method thereof. Background Art

[0002] Endoscopic ultrasound (EUS)-guided pancreatic pseudocyst puncture is one of the ideal non-surgical treatments for pancreatic pseudocysts. Under EUS guidance, the optimal location for puncture can be selected, and a drainage stent or catheter can be placed between the digestive tract and the pseudocyst. This method is not only highly effective but also minimally invasive and associated with fewer complications.

[0003] Commonly used drainage stents in clinical practice are double-mushroom-head metal stents. These double-mushroom-head structures can be placed in the digestive tract and within the pseudocyst, respectively, to establish stable drainage channels. Double-mushroom-head metal stents are made of a woven mesh, with sharp corners and mesh grids at the ends. These stents can easily rub against the inner wall of the pseudocyst, causing tissue damage. Given the rich vascularity of the pancreas, prolonged placement of these stents can increase the risk of bleeding.

[0004] In addition, the catheters commonly used in clinical practice have a small diameter and are long. The fluid accumulated inside the pseudocyst can easily stay in the tube and coagulate, causing blockage. Therefore, if the catheter is placed for a long time, blockage is likely to occur. Summary of the Invention

[0005] The present invention provides a pancreatic pseudocyst drainage stent, a stent system and a method of using the same, which can fully drain the accumulated fluid inside the pseudocyst and protect the inner wall of the pseudocyst, thereby improving the quality of surgical treatment.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A pancreatic pseudocyst drainage stent comprises a stent body and an airbag portion, wherein: the stent body is a grid-shaped stent woven from medical memory metal, and the stent body is in the shape of a straight cylinder; a recovery line is provided on the proximal side of the stent body, and the recovery line is provided with a knot; the airbag portion comprises a distal airbag, a proximal airbag, a coating, an airway, an air supply tube and an inflation one-way valve; the distal airbag and the proximal airbag are respectively arranged on the distal side and the proximal side of the stent body, the coating is arranged between the distal airbag and the proximal airbag, and the distal airbag, the proximal airbag and the coating are wrapped around the entire circumference of the stent body; the airway connects the distal airbag with the proximal airbag; one end of the air supply tube is connected to the proximal airbag, and the other end of the air supply tube is detachably connected to the inflation tube portion of the conveyor through the inflation one-way valve to receive gas injected from the outside, and the distal airbag and the proximal airbag can be inflated under the action of the gas.

[0008] Preferably, a valve cavity and a connecting cavity are provided inside the inflation one-way valve, and a baffle and a floating ball are provided inside the valve cavity; a gap is left between the two ends of the baffle and the cavity wall of the valve cavity, and the gap can allow gas to circulate; an air inlet is provided at the proximal end of the valve cavity, and an air outlet is provided at the distal end of the valve cavity, and the air outlet is connected to the other end of the gas pipe; the diameter of the air inlet is smaller than the air outlet and the floating ball, and the floating ball can move in the space enclosed by the baffle, the air inlet and the cavity wall of the valve cavity to open or close the air inlet; a first magnetic pad with a center hole is placed in the connecting cavity, and the first magnetic pad can be magnetically attracted to connect with the second magnetic pad provided on the distal side of the inflation tube.

[0009] Preferably, the air inlet is a funnel-shaped inclined air inlet that gradually expands in diameter from the proximal side toward the distal side.

[0010] Preferably, when the inflation tube portion is connected to the inflation one-way valve, the floating ball can move from the proximal side to the distal side in the valve cavity under the air pressure of the inflation tube portion to open the air inlet; when the inflation tube portion is separated from the inflation one-way valve, the floating ball can move from the distal side to the proximal side in the valve cavity under the air pressure of the distal airbag and the proximal airbag to close the air inlet.

[0011] Preferably, the retrieval wire is intricately wound around a plurality of grids at the proximal end of the stent body.

[0012] In order to achieve the above-mentioned object of the invention, the present invention also provides the following technical solutions:

[0013] A pancreatic pseudocyst drainage stent system comprises the aforementioned pancreatic pseudocyst drainage stent and a conveyor, the conveyor comprising a delivery tube assembly, an inflation tube portion, and an operating handle, wherein: the delivery tube assembly comprises an outer tube and an inner tube, the outer tube having an outer tube lumen provided therein; the inner tube having an inner tube lumen provided therein, the inner tube lumen being capable of allowing a guidewire instrument to pass through; a conical guide head being provided at the distal end of the inner tube, and a limiting boss being provided at the proximal end of the inner tube; the stent body being capable of being folded up to be placed between the inner tube and the outer tube; a second magnetic pad being provided at the distal end of the inflation tube portion, and an air pump interface being provided at the proximal end of the inflation tube portion, the air pump interface being capable of being connected to an external air pump to receive gas injected therein, and the inflation tube portion being capable of transmitting the gas to the airbag portion; a first lumen and a second lumen being provided at the interior of the operating handle, the first lumen being in communication with and fixedly connected to the outer tube lumen of the outer tube; the second lumen being capable of allowing the inflation tube portion to pass through and be fixed therein; the inner tube between the conical guide head and the limiting boss being capable of axially sliding in the outer tube lumen and the first lumen.

[0014] Preferably, the outer periphery of the inflation tube portion is reduced in diameter along its axial direction to form an insertion port, and a second magnetic pad is provided on the outer side of the insertion port. The insertion port can be inserted into the connecting cavity and connected with the air inlet, and the second magnetic pad can be magnetically attracted to the first magnetic pad for connection.

[0015] Preferably, a stent receiving groove is provided on the outer periphery of the distal end side of the inner tube, and the stent receiving groove can accommodate the collapsed stent body.

[0016] Preferably, the outer periphery of the distal end side of the outer tube is provided with a side groove along its axial direction, and the side groove allows the gas delivery tube to extend to the outside to be connected to the distal end of the inflation tube portion through the inflation one-way valve.

[0017] In order to achieve the above-mentioned object of the invention, the present invention also provides the following technical solutions:

[0018] A method for using a pancreatic pseudocyst drainage stent system, using the aforementioned pancreatic pseudocyst drainage stent system and a guide wire device for drainage, specifically comprising: placing one end of the guide wire device inside the pancreatic pseudocyst and the other end of the guide wire device outside the human body; passing the guide wire device through the inner tube of a conveyor, and advancing the conveyor until the conical guide head of the inner tube enters the interior of the pancreatic pseudocyst; holding an operating handle and sliding it toward the outside of the body, the operating handle drives the outer tube connected thereto to move to extend the stent body and Release, the distal side of the stent body is placed inside the pancreatic pseudocyst, and the proximal side of the stent body is placed in the digestive tract; the distal airbag and the proximal airbag are inflated through the inflation tube and the gas supply tube, and after inflation, the distal airbag and the proximal airbag can respectively clamp the pancreatic pseudocyst and the digestive tract; hold the operating handle to withdraw the conveyor from the body, drive the inflation tube to move outward, and when the tension on the inflation tube is greater than the connection force between it and the inflation one-way valve, it is separated, and the inflation one-way valve is blocked under the air pressure of the airbag to achieve sealing.

[0019] Preferably, after the stent body is placed for a period of time, a first instrument with a puncturing function is inserted from the instrument channel of the endoscope; the proximal airbag is punctured using the first instrument; a second instrument with a clamping function is replaced, and the second instrument is hooked on the knot of the retrieval line of the stent body, and the endoscope is held and withdrawn from the body together with the clamping instrument. The stent body is pulled toward the center by the retrieval line to reduce its diameter so as to slide out of the pancreatic pseudocyst and return to the digestive tract, and the endoscope is continued to be held and withdrawn from the body together with the stent body through the clamping instrument.

[0020] The pancreatic pseudocyst drainage stent provided by this invention innovatively features two airbags at each end of the stent. When inflated, these airbags expand, securing the drainage stent to the pseudocyst and digestive tract. The airbag structure does not damage internal tissues and can be inflated or deflated according to clinical needs.

[0021] The present invention provides a pancreatic pseudocyst drainage stent system and its use method, comprising the aforementioned stent and a delivery device. The system places the stent between the digestive tract and the pseudocyst, with the distal end of the stent positioned within the pseudocyst and the proximal end within the digestive tract. The distal and proximal airbags are inflated and locked into place, effectively securing the stent to prevent displacement. Furthermore, the distal airbag isolates the stent from pancreatic tissue to prevent friction and tissue damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only 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 3D diagram of a pancreatic pseudocyst drainage stent according to an embodiment of the present invention.

[0024] Figure 2 4 is a cross-sectional view of a pancreatic pseudocyst drainage stent according to an embodiment of the present invention.

[0025] Figure 3 Schematic cross-sectional view of the docking of the inflation one-way valve and the distal end of the inflation tube portion in an embodiment of the present invention.

[0026] Figure 4 3D diagram of a pancreatic pseudocyst drainage stent system according to an embodiment of the present invention.

[0027] Figure 5 4 is a cross-sectional view of a pancreatic pseudocyst drainage stent system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be further described in detail below through examples and in conjunction with the accompanying drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present invention with reference to the accompanying drawings is intended to explain the overall inventive concept of the present invention and should not be construed as limiting the present invention.

[0029] In addition, in the following detailed description, for ease of explanation, numerous specific details are set forth to provide a comprehensive understanding of the disclosed embodiments. However, it is apparent that one or more embodiments can be practiced without these specific details. In other cases, well-known structures and devices are shown in diagrammatic form to simplify the accompanying drawings.

[0030] It should be noted that the word "comprising" does not exclude other elements or steps, and the word "one" or "an" does not exclude a plurality; the directions or positional relationships indicated by "one end", "the other end", "inside", "outside", "front", "back", "distal side", "proximal side", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. "First" and "second" are used to distinguish the names of different components and are not for the purpose of ranking or indicating importance or primary and secondary distinctions. In addition, any element number in the claims should not be understood as limiting the scope of the present disclosure.

[0031] The inventors discovered that clinically used drainage stents, due to their double mushroom-shaped structure, are prone to tissue damage and subsequent bleeding due to their mesh and sharp corners. Furthermore, the catheter, due to its elongated, tubular shape, is prone to fluid accumulation and blockage. Adding a balloon structure to the stent could address these clinical challenges. The balloon structure prevents tissue damage, while also preventing blockage due to fluid accumulation due to the space created by the stent's expansion.

[0032] According to an overall technical concept of the present invention, a pancreatic pseudocyst drainage stent includes a stent body and an airbag part, wherein: the stent body is a grid-shaped stent woven from medical memory metal, and the stent body is in the shape of a straight cylinder; a recovery line is provided on the proximal side of the stent body, and the recovery line is provided with a knot; the airbag part includes a distal airbag, a proximal airbag, a coating, an airway, an air supply tube and an inflation one-way valve; the distal airbag and the proximal airbag are respectively arranged on the distal side and the proximal side of the stent body, the coating is arranged between the distal airbag and the proximal airbag, and the distal airbag, the proximal airbag and the coating are wrapped around the entire circumference of the stent body; the airway connects the distal airbag with the proximal airbag; one end of the air supply tube is connected to the proximal airbag, and the other end of the air supply tube is detachably connected to the inflation tube part of the conveyor through the inflation one-way valve to receive gas injected from the outside, and the distal airbag and the proximal airbag can be inflated under the action of the gas.

[0033] In the embodiment of the present invention, the “distal side” refers to a direction close to a target operation position, and the “proximal side” refers to a direction close to an operator.

[0034] Example 1

[0035] like Figures 1 to 3 As shown, in an embodiment of the present invention, a pancreatic pseudocyst drainage stent 100 includes a stent body 110 and a balloon portion 120 .

[0036] Stent body 110 is a mesh-like stent woven from medical memory metal, forming a straight cylindrical shape. Because it is made of medical memory metal, stent body 110 can expand and return to its original, uncontracted state. Stent body 110 can be pinched and collapsed at low temperatures, but returns to its original straight cylindrical shape at room temperature (or within the body).

[0037] A retrieval line 111 is provided on the proximal side of the stent body 110, and is provided with a knot 111a. In some preferred embodiments, the retrieval line 111 is intricately wound around multiple grids at the proximal end of the stent body 110. Specifically, one end of the retrieval line 111 passes through one grid of the stent body 110 from bottom to top, then passes through an adjacent grid of the stent body 110 from top to bottom, and so on, so that the retrieval line 111 is sequentially wound around multiple grids. The knot 111a is used to pull the retrieval line 111 under the operation of the clamping device. When pulled, the retrieval line 111 can gather the multiple grids, thereby facilitating the overall folding of the stent body 110.

[0038] The airbag unit 120 includes a distal airbag 121, a proximal airbag 122, a coating 123, an airway 124, an air delivery tube 125, and an inflation check valve 126. The distal airbag 121 and the proximal airbag 122 are respectively disposed on the distal and proximal sides of the stent body 110. The coating 123 is disposed between the distal airbag 121 and the proximal airbag 122. Together, the distal airbag 121, the proximal airbag 122, and the coating 123 wrap around the entire circumference of the stent body 110. The airway 124 connects the distal airbag 121 with the proximal airbag 122. This means that after gas enters the proximal airbag 122, it can be transferred to the distal airbag 121 through the airway 124. One end of the air delivery tube 125 is connected to the proximal airbag 122 and can be disposed, for example, at the top of the proximal airbag 122. The other end of the gas delivery tube 125 is detachably connected to the inflation tube portion 220 of the delivery device 200 via an inflation check valve 126 to receive externally injected gas. The distal and proximal balloons 121 and 122 are inflated by the gas, and the inflated balloons enable the stent body 110 to be securely secured to a pancreatic cyst or within the digestive tract.

[0039] In some preferred embodiments, a valve chamber 1261 and a connecting chamber 1262 are provided within the inflation check valve 126, and a baffle 1263 and a floating ball 1264 are provided within the valve chamber 1261. Preferably, the baffle 1263 can be positioned in the center of the valve chamber 1261, with the size of the baffle 1263 being smaller than the size of the air outlet 1266, thereby leaving a gap between the sides of the baffle 1263 and the walls of the valve chamber 1261, allowing gas to flow through. The floating ball 1264 is a lightweight spherical structure that can be propelled by air pressure. An air inlet 1265 is provided at the proximal end of the valve chamber 1261, and an air outlet 1266 is provided at the distal end of the valve chamber 1261. The air outlet 1266 of the valve chamber 1261 is connected to the other end of the gas supply pipe 125. The diameter of the air inlet 1265 is smaller than that of the air outlet 1266 and the floating ball 1264. Such a size setting allows the floating ball 1264 to move in the space enclosed by the baffle 1263, the air inlet 1265 and the cavity wall of the valve cavity 1261 to open or close the air inlet 1265.

[0040] In some preferred embodiments, the air inlet 1265 is a funnel-shaped, sloped air inlet that gradually expands in diameter from the proximal end toward the distal end of the air inlet 1265. The funnel-shaped slope of the air inlet 1265 facilitates the movement of the floating ball 1264, while the tube body forms a passage for the inflation tube 220 to be inserted, thereby connecting the inflation check valve 126 to the inflation tube 220.

[0041] When the floating ball 1264 is subjected to air pressure from the proximal side toward the distal side, it is pushed from the proximal side toward the distal side to open the air inlet 1265. However, due to the presence of the baffle 1263, the floating ball 1264 does not escape from the valve chamber 1261 and enter the air supply pipe 125. At the same time, the gas can flow through the gap between the ends of the baffle 1263 and the cavity wall of the valve chamber 1261 to the air outlet 1266 and enter the air supply pipe 1265.

[0042] After the inflation check valve 126 is separated from the inflation tube 220 of the conveyor 200, the air pressure from the proximal side to the distal side is released. The gas in the airbag 120 pushes against the floating ball 1264, causing the floating ball 1264 to be subjected to air pressure from the distal side to the proximal side. When subjected to air pressure from the distal side to the proximal side, the floating ball 1264 is pushed from the distal side to the proximal side, blocking or closing the air inlet 1264. The entire airbag 120 is now sealed, thereby stably maintaining the airbag 120's inflated state and achieving a stable engagement with the pseudocyst or digestive tract. The greater the air pressure in the airbag 120, the more the floating ball 1264 is squeezed and deformed, and the more it conforms to the air inlet 1264 or the slope of the funnel.

[0043] Connecting cavity 1262 houses a first magnetic pad 1267, which has a central hole connected to the proximal end of air inlet 1264 for gas circulation. First magnetic pad 1267 is magnetically attracted to a second magnetic pad 221 located distally of the inflation tube 220. This magnetic connection allows the two to be tightly connected while also allowing them to separate under a force greater than the magnetic attraction. This allows for releasable connection between the inflation check valve 126 and the inflation tube 220 of the conveyor 200.

[0044] The pancreatic pseudocyst drainage stent provided in this embodiment innovatively features two balloons at each end of the stent. When inflated, these balloons expand, securing the drainage stent to the pseudocyst and digestive tract. The balloon structure does not damage internal tissue and can be inflated or deflated according to clinical needs.

[0045] Example 2

[0046] like Figures 4 and 5 As shown, in an embodiment of the present invention, the pancreatic pseudocyst drainage stent system includes the stent 100 of Example 1 and a conveyor 200 , wherein the conveyor 200 includes a conveying tube assembly 210 , an inflation tube portion 220 and an operating handle 230 .

[0047] The delivery tube assembly 210 includes an outer tube 211 and an inner tube 212. The outer tube 211 is provided with an outer tube lumen 2111. The inner tube 212 is provided with an inner tube lumen 2121, which allows a guidewire instrument (not shown) to pass through, allowing it to enter the human body under the guidance of the guidewire instrument. A conical guide head 2122 is provided at the distal end of the inner tube 212. The conical guide head 2122 also has a lumen inside, which is also provided for the passage of a guidewire instrument. The conical guide head 2122 can be inserted into a pancreatic pseudocyst. A stop boss 2123 is provided at the proximal end of the inner tube 212 to prevent the operating handle 230 from detaching from the inner tube 212 when sliding axially along the inner tube 212. The stent body 110 can be collapsed to be positioned between the inner tube 211 and the outer tube 212. Once collapsed, the entire stent system 200 can be introduced into the human body under the guidance of a guidewire instrument.

[0048] A second magnetic pad 221 is provided on the distal end of the inflation tube portion 220, which can be magnetically attracted to the first magnetic pad 1267 to achieve detachable communication between the inflation tube portion 220 and the inflation check valve 126. An air pump interface 222 is provided on the proximal end of the inflation tube portion 220, which can be connected to an external air pump to receive gas injected therein. The inflation tube portion 220 then transmits the gas to the airbag portion 120. In some preferred embodiments, the outer periphery of the inflation tube portion 220 is reduced in diameter along its axial direction to form an insertion port 223, the exterior of which is sheathed with the second magnetic pad 221. The insertion port 223 can be inserted into the connecting cavity 1262 and communicated with the air inlet 1265.

[0049] The operating handle 230 is internally provided with a first lumen 231 and a second lumen 232. The first lumen 231 is connected and fixedly connected to the outer tube lumen 2111. This means that when the operating handle 230 is gripped and moved, the outer tube 211 moves synchronously. The second lumen 232 allows the inflation tube 220 to pass through and securely secure it. The inner tube 212, between the tapered guide head 2122 and the limiting boss 2123, is axially slidable within the outer tube lumen 2111 and the first lumen 231.

[0050] In some preferred embodiments, a stent receiving groove 2124 is provided on the outer periphery of the distal end of the inner tube 212 , and the stent body 110 can be accommodated in the receiving groove.

[0051] In some preferred embodiments, a side groove 2112 is provided along the axial direction of the outer periphery of the distal side of the outer tube 211, and the side groove 2112 allows the gas supply pipe 125 to extend to the outside of the outer tube 211 and be connected to the distal end of the inflation tube portion 220 through the inflation one-way valve 126.

[0052] The pancreatic pseudocyst drainage stent system provided by the present invention comprises the stent provided in Example 1 and a delivery device capable of carrying and releasing the stent to a target location in the human body. This system allows the stent to be placed between the digestive tract and the pseudocyst, with the distal end of the stent positioned within the pseudocyst and the proximal end within the digestive tract. The distal and proximal airbags are inflated and locked into place, effectively securing the stent to prevent displacement. Furthermore, the distal airbag isolates the stent from pancreatic tissue to prevent friction and tissue damage.

[0053] Example 3

[0054] The method for using the pancreatic pseudocyst drainage stent system provided in an embodiment of the present invention uses the pancreatic pseudocyst drainage stent system 200 and the guide wire device of Example 2 for drainage, comprising: placing one end of the guide wire device inside the pancreatic pseudocyst and the other end of the guide wire device outside the human body. Next, the guide wire device is passed through the inner tube 212 of the conveyor 210, and the conveyor 210 is advanced until the conical guide head 2122 of the inner tube 212 enters the interior of the pancreatic pseudocyst. The operating handle 230 is held and slid outward from the body, and the operating handle 230 drives the outer tube 212 connected thereto to move so as to extend and release the stent body 110, the distal side of the stent body 110 is placed inside the pancreatic pseudocyst, and the proximal side of the stent body 110 is placed in the digestive tract. Air is inflated into the distal balloon 121 and proximal balloon 122 through the inflation tube 220 and gas delivery tube 125. Once inflated, the distal balloon 121 and proximal balloon 122 respectively block the pancreatic pseudocyst and the digestive tract. After the stent body 110 is engaged with the body, the operating handle 230 is grasped to withdraw the delivery device 210 from the body, driving the inflation tube 220 outward. When the tension on the inflation tube 220 exceeds the connection force between it and the inflation check valve 126, the inflation tube 220 separates, and the inflation check valve 126 is blocked by the air pressure from the balloon, achieving a seal.

[0055] In some preferred embodiments, after the stent body 110 has been placed for a period of time, a first instrument with a puncturing function is inserted through the instrument channel of the endoscope. The first instrument is used to puncture the proximal balloon 122. A second instrument with a clamping function is then replaced and hooked onto the knot 111a of the retrieval line 111 of the stent body 110. The endoscope, along with the clamping instrument, is then withdrawn from the body. The retrieval line 111 pulls the stent body 110 toward the center, reducing its diameter and allowing it to slide out of the pancreatic pseudocyst and back into the digestive tract. The endoscope is then continued to be grasped and withdrawn from the body through the clamping instrument, along with the stent body 110.

[0056] Specifically, the endoscopist uses an endoscopic ultrasound (EUS) to select the optimal location for puncturing the pancreatic pseudocyst under EUS guidance. One end of the guidewire is then placed inside the pancreatic pseudocyst, while the other end is placed outside the body, establishing a delivery route for the stent 100. This system arrives factory-installed, with the stent body already positioned in the stent receiving slot and held between the outer tube 211 and the inner tube 212. The stent's air delivery tube 125 is securely connected to the inflation tube 220.

[0057] The endoscopist inserts one end of an external guidewire into the inner lumen 2121 of the inner tube 212 through the top of the tapered guide head 2122 in the stent delivery device 200. The stent delivery device 200 then follows the guidewire and enters the body. The guidewire extends from the limiting boss 2123 in the inner tube 212 of the stent delivery device 200, and the stent delivery device 200 is continuously advanced until the tapered guide head 2122 enters the pseudocyst, placing the stent between the digestive tract and the pseudocyst. The endoscopist holds the inner tube 212 stationary and slides the operating handle 230 toward the body. The stent body 110 slowly extends and expands to its original state until all stent bodies 110 are free of the outer tube 211. The distal end of the stent body 110 is placed inside the pseudocyst, and the proximal end of the stent body 110 is placed inside the digestive tract.

[0058] The endoscopist connects the air pump to the air pump interface 222 of the inflation tube 220 outside the body, and operates the air pump to inflate the air bag through the inflation tube 220 and the air supply tube 125. When the air bag is fully expanded and filled, the distal and proximal air bags are inflated to clamp the pseudocyst and the digestive tract, which can effectively fix the position of the stent body 110 to prevent displacement.

[0059] The endoscopist grasps the operating handle 230 to withdraw the conveyor 200 from the body. The one-way valve 126 and the inflation tube 220 are subjected to a pulling force during withdrawal from the conveyor 200. This pulling force is greater than the attractive force between the first magnetic pad 1267 and the second magnetic pad 221, causing the one-way valve 126 to separate from the inflation tube 220. The floating ball 1264 within the one-way valve 126 is pushed toward the air inlet 1265 by the air pressure within the airbag, blocking and closing the air inlet 1265 and thus achieving airbag sealing. The higher the pressure within the airbag, the better the one-way valve seal.

[0060] After stent 100 has been placed for a period of time, the endoscopist operates the digestive endoscope, enters the stent placement site in the human body, and inserts a first instrument with a puncture or cutting function through the digestive endoscope instrument channel. Guided by the endoscopic image, the first instrument punctures the proximal airbag 121 of the stent, releasing the gas within. The endoscopist then switches to a second instrument with a clamping function. Guided by the endoscopic image, the second instrument hooks the knot 111a of the retrieval line 111 at the proximal end of the stent body 110. The endoscopist then withdraws the endoscope and the clamping instrument from the body. As the clamping instrument pulls the stent 100 out of the body, the retrieval line 111 transmits the tension, pulling the mesh on the proximal side of the stent body 111 inward, reducing the diameter of the stent body and allowing the stent 100 to slide out of the pseudocyst and back into the digestive tract. The endoscopist then withdraws the endoscope and the stent 100 from the body through the clamping instrument.

[0061] The method of use provided by the embodiment of the present invention is simple to operate and can be easily promoted in clinics.

[0062] Those skilled in the art will appreciate that the embodiments described above are exemplary and that they may be improved upon. The structures described in the various embodiments may be freely combined without causing any conflict in structure or principle.

[0063] Although the present invention has been described in conjunction with the accompanying drawings, the embodiments disclosed in the drawings are intended to exemplify the preferred implementations of the present invention and should not be construed as limiting the present invention.

[0064] Although some embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the present general inventive concept, the scope of which is defined in the claims and their equivalents.

Claims

1. A pancreatic pseudocyst drainage stent, characterized in that It includes a stent body and an airbag part, wherein: The stent body is a mesh-shaped stent woven from medical memory metal and is in a straight cylindrical shape. A recovery line is provided on the proximal side of the stent body, and the recovery line is provided with a knot. The airbag portion includes a distal airbag, a proximal airbag, a coating, an airway, an air supply tube and an inflation one-way valve; the distal airbag and the proximal airbag are respectively arranged on the distal side and the proximal side of the stent body, and the coating is arranged between the distal airbag and the proximal airbag, and the distal airbag, the proximal airbag and the coating are wrapped around the entire circumference of the stent body; the airway connects the distal airbag with the proximal airbag; one end of the air supply tube is connected to the proximal airbag, and the other end of the air supply tube is detachably connected to the inflation tube portion of the conveyor through the inflation one-way valve to receive gas injected from the outside, and the distal airbag and the proximal airbag can be inflated under the action of the gas.

2. The pancreatic pseudocyst drainage stent according to claim 1, characterized in that: A valve cavity and a connecting cavity are provided inside the inflation one-way valve, and a baffle and a floating ball are provided inside the valve cavity; a gap is left between the two ends of the baffle and the cavity wall of the valve cavity, and the gap can allow gas to circulate; an air inlet is provided at the proximal end of the valve cavity, and an air outlet is provided at the distal end of the valve cavity, and the air outlet is connected to the other end of the gas pipe; the diameter of the air inlet is smaller than the air outlet and the floating ball, and the floating ball can move in the space enclosed by the baffle, the air inlet and the cavity wall of the valve cavity to open or close the air inlet; the connecting cavity is provided with a first magnetic pad with a center hole, and the first magnetic pad can be magnetically attracted to connect with the second magnetic pad provided on the distal side of the inflation tube.

3. The pancreatic pseudocyst drainage stent according to claim 2, characterized in that: The air inlet is a funnel-shaped inclined air inlet that gradually expands in diameter from the proximal side toward the distal side.

4. The pancreatic pseudocyst drainage stent according to claim 2 or 3, characterized in that: When the inflation tube portion is connected to the inflation one-way valve, the floating ball can move from the proximal side to the distal side in the valve cavity under the air pressure of the inflation tube portion to open the air inlet; when the inflation tube portion is separated from the inflation one-way valve, the floating ball can move from the distal side to the proximal side in the valve cavity under the air pressure of the distal airbag and the proximal airbag to close the air inlet.

5. The pancreatic pseudocyst drainage stent according to claim 1, characterized in that: The retrieval wire is intricately wound around a plurality of grids at the proximal end of the stent body.

6. A pancreatic pseudocyst drainage stent system, characterized in that The pancreatic pseudocyst drainage stent and delivery device according to any one of claims 1 to 5, wherein the delivery device comprises a delivery tube assembly, an inflation tube portion, and an operating handle, wherein: The delivery tube assembly includes an outer tube and an inner tube, wherein an outer tube lumen is provided inside the outer tube; an inner tube lumen is provided inside the inner tube, and the inner tube lumen is provided for a guide wire instrument to pass through; a conical guide head is provided on the distal end side of the inner tube, and a limiting boss is provided on the proximal end side of the inner tube; the stent body can be folded to be placed between the inner tube and the outer tube; A second magnetic pad is provided on the distal end of the inflation tube portion, and an air pump interface is provided on the proximal end of the inflation tube portion. The air pump interface can be connected to an extracorporeal air pump to receive the gas injected therein, and the inflation tube portion can transmit the gas to the airbag portion; A first lumen and a second lumen are provided inside the operating handle, wherein the first lumen is communicated with and fixedly connected to the outer tube lumen of the outer tube; the second lumen is for the inflation tube to pass through and be fixed; The inner tube between the conical guide head and the limiting boss can slide axially in the outer tube cavity and the first cavity.

7. The pancreatic pseudocyst drainage stent system according to claim 6, characterized in that: The outer periphery of the inflation tube portion is reduced in diameter along its axial direction to form an insertion port, and a second magnetic pad is provided on the outside of the insertion port. The insertion port can be inserted into the connecting cavity and connected to the air inlet, and the second magnetic pad can be magnetically attracted to the first magnetic pad for connection.

8. The pancreatic pseudocyst drainage stent system according to claim 6 or 7, characterized in that: A stent receiving groove is provided on the outer periphery of the distal end side of the inner tube, and the stent receiving groove can accommodate the collapsed stent body.

9. The pancreatic pseudocyst drainage stent system according to any one of claims 6 to 8, characterized in that: The outer periphery of the distal end side of the outer tube is provided with a side groove along its axial direction, and the side groove allows the gas delivery pipe to extend to the outside to be connected to the distal end of the inflation tube portion through the inflation one-way valve.

10. A method for using a pancreatic pseudocyst drainage stent system, characterized in that Drainage is performed using the pancreatic pseudocyst drainage stent system and guidewire device according to any one of claims 6 to 9, specifically comprising: placing one end of the guide wire device inside the pancreatic pseudocyst and the other end of the guide wire device outside the human body; Passing the guidewire instrument through the inner tube of the delivery device, and advancing the delivery device until the tapered guide tip of the inner tube enters the interior of the pancreatic pseudocyst; Holding the operating handle and sliding it toward the outside of the body, the operating handle drives the outer tube connected thereto to move so as to extend and release the stent body, with the distal end of the stent body being placed inside the pancreatic pseudocyst and the proximal end of the stent body being placed in the digestive tract; The distal airbag and the proximal airbag are inflated through the inflation tube and the air delivery tube, and the distal airbag and the proximal airbag can respectively block the pancreatic pseudocyst and the digestive tract after being inflated; Holding the operating handle, the conveyor is withdrawn from the body, driving the inflation tube to move outward. When the pulling force on the inflation tube is greater than the connection force between it and the inflation one-way valve, it is separated, and the inflation one-way valve is blocked under the air pressure of the airbag part to achieve sealing.

11. The method for using the pancreatic pseudocyst drainage stent system according to claim 10, characterized in that: After the stent body is placed for a period of time, a first instrument with a puncture function is inserted through the instrument channel of the endoscope; puncturing the proximal balloon using the first instrument; Replace the second instrument with a clamping function, hook the second instrument on the knot of the retrieval line of the stent body, hold the endoscope and withdraw it from the body together with the clamping instrument, the stent body is pulled toward the center by the retrieval line to reduce its diameter so as to slide out of the pancreatic pseudocyst and return to the digestive tract, continue to hold the endoscope and withdraw it from the body together with the stent body through the clamping instrument.

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