Body fluid drainage stent

Abstract

The utility model provides a kind of body fluid drainage support, it can be discharged outside without secondary operation, avoid to bring secondary injury to patient, reduce the pain of patient.Body fluid drainage support includes: support main body, for putting into biliary tract or pancreatic duct;Traction line, fixedly connected to one end of support main body, for extending into duodenum;And one or more traction parts, including inflatable body and degradable coating covering inflatable body bound on traction line;When degradable coating is degraded to expose inflatable body, inflatable body absorbs liquid and expands, for under the peristalsis of intestine, traction line is driven, to pull support main body to outside.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a body fluid drainage stent. Background Technology

[0002] The biliary and pancreatic systems function to secrete, store, concentrate, and transport bile or pancreatic juice, playing a crucial regulatory role in the drainage of bile or pancreatic juice into the duodenum. In the event of biliary or pancreatic obstruction, implanting a biliary or pancreatic stent at the site of narrowing or obstruction is an effective treatment method. Currently, there are two main types of biliary or pancreatic stents used: self-expanding metal stents and fixed-diameter plastic stents. Metal stents are primarily made of non-degradable metallic materials such as stainless steel, nickel-titanium alloys, platinum-iridium alloys, cobalt-chromium alloys, tantalum, or titanium, and are relatively expensive; plastic stents are primarily made of non-degradable plastic materials and are less expensive.

[0003] However, when treating benign biliary or pancreatic obstructions, these non-degradable biliary or pancreatic stents, if left in the body for a long period, can cause side effects, necessitating a second surgery to remove them. This results in secondary harm to the patient, increasing their pain and fear. Furthermore, using entirely biodegradable materials to fabricate stents would significantly increase costs, further burdening patients financially. Utility Model Content

[0004] The purpose of this invention is to provide a body fluid drainage stent that can be drained from the body without secondary surgery, thus avoiding secondary harm to the patient and reducing the patient's pain.

[0005] Based on this, an embodiment of the present invention discloses a body fluid drainage stent, comprising:

[0006] The main body of the stent is used to place it into the bile duct or pancreatic duct;

[0007] A traction suture, fixedly connected to one end of the stent body, is used to insert into the duodenum; and

[0008] One or more traction elements, including an expandable body bound to a traction wire and a biodegradable coating covering the expandable body; when the biodegradable coating is degraded to expose the expandable body, the expandable body absorbs liquid and expands to drive the traction wire under intestinal peristalsis to pull the stent body outside the body.

[0009] Using the above-described technical solution, a duodenoscopy is used to retrogradely insert a cannula into the bile duct or pancreatic duct, and the main body of a fluid drainage stent is placed inside. The traction suture and traction device of the fluid drainage stent remain in the duodenum. Subsequently, over time, the biodegradable coating of the traction device is gradually enzymatically decomposed into water and carbon dioxide within the intestine, exposing the expandable body of the traction device. This expands by absorbing water within the intestine. Then, the expanded bulb, under the influence of intestinal peristalsis, pulls the traction suture, drawing the stent main body from the bile duct or pancreatic duct into the ileum and jejunum, and finally out through the anus. In other words, the main body of the fluid drainage stent of this application can be expelled from the body solely by intestinal peristalsis under the traction of the traction suture and traction device, without the need for a secondary surgery, thus avoiding secondary harm to the patient and reducing their pain and fear.

[0010] According to one embodiment of this application, the expandable body is a TPE component; the biodegradable coating is a PLLA component.

[0011] According to one embodiment of this application, the coefficient of expansion of the expandable body is between 50 and 100.

[0012] By adopting the above technical solution, it is possible not only to ensure that the expandable body has a small volume before expansion to avoid being affected by intestinal peristalsis and having an adverse effect on the intestine, but also to ensure that the expandable body has a large volume after expansion so as to forcefully pull the traction line under intestinal peristalsis.

[0013] According to one embodiment of this application, multiple traction elements are connected in series at intervals on the traction line.

[0014] The above technical solution is adopted so that while being restrained by the traction line, expansion space is reserved for the adjacent traction component 30.

[0015] According to one embodiment of this application, the traction member has a through hole penetrating the expandable body, the inner diameter of which is larger than the diameter of the traction line.

[0016] According to one embodiment of this application, the traction line has a plurality of plugs arranged at intervals, the outer diameter of the plugs being larger than the inner diameter of the through holes.

[0017] According to one embodiment of this application, the plug is a line knot, and the distance between two adjacent line knots is greater than or equal to the expansion diameter of the expandable body.

[0018] The above technical solution is adopted to prevent the knot from blocking the expansion body from absorbing liquid and expanding, thus avoiding damage to the expansion body.

[0019] According to one embodiment of this application, the diameter of the traction member is between 2 mm and 3.5 mm; the expansion diameter of the expandable body is between 10 mm and 20 mm.

[0020] According to one embodiment of this application, the support body includes an inner tube with a drainage channel, an outer tube fitted onto the inner tube, and a plurality of elastic arms extending outwardly from the inner tube; the plurality of elastic arms are arranged opposite to each other at both ends of the outer tube.

[0021] According to one embodiment of this application, the inner tube is made of PTFE; the outer tube and the elastic arm are made of Pebax.

[0022] According to one embodiment of this application, the inner tube is fused to the outer tube, and the traction line is fixedly connected between the inner tube and the outer tube.

[0023] According to one embodiment of this application, the support body is a metal support or a plastic support.

[0024] According to one embodiment of this application, the expandable body is an expandable sphere or an expandable cylinder. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A three-dimensional schematic diagram of a body fluid drainage stent provided in one embodiment of this application;

[0027] Figure 2 It shows Figure 1 A cross-sectional schematic diagram of the fluid drainage stent shown;

[0028] Figure 3 A schematic diagram showing the expanded sphere in the body fluid drainage stent according to the above embodiments of this application after expansion is shown.

[0029] Figure 4 It shows Figure 3 A cross-sectional schematic diagram of the fluid drainage stent shown;

[0030] Figure 5 A modified example of a body fluid drainage stent according to the above embodiments of this application is shown;

[0031] Figure 6 A schematic diagram of the structure of the expandable column in the fluid drainage stent according to the above-described modified example of this application after expansion is shown.

[0032] Reference numerals: 1. Fluid drainage stent; 10. Stent body; 11. Inner tube; 110. Drainage channel; 12. Outer tube; 13. Elastic arm; 20. Traction line; 200. Block; 30. Traction component; 300. Through hole; 31. Expandable body; 311. Expandable sphere; 312. Expandable column; 32. Biodegradable coating. Detailed Implementation

[0033] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0034] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0037] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0038] Considering the treatment of benign biliary or pancreatic obstruction: fully biodegradable biliary or pancreatic stents are expensive, increasing the financial burden on patients; non-biodegradable biliary or pancreatic stents require secondary surgery for removal, causing further harm and increasing patient suffering and fear. To address this issue, this application provides a fluid drainage stent that can be removed from the body without secondary surgery, avoiding secondary harm and reducing patient suffering.

[0039] Specifically, please refer to Figures 1 to 4 One embodiment of this application provides a body fluid drainage stent 1, which may include a stent body 10 for placement in the bile duct or pancreatic duct, a traction wire 20, and one or more traction elements 30. The traction wire 20 is fixedly connected to one end of the stent body 10 for insertion into the duodenum. The traction element 30 includes an expandable body 31 bound to the traction wire 20 and a biodegradable coating 32 covering the expandable body 31; when the biodegradable coating 32 is degraded to expose the expandable body 31, the expandable body 31 absorbs liquid and expands, thereby pulling the traction wire 20 under intestinal peristalsis to pull the stent body 10 out of the body.

[0040] More specifically, the expandable body 31 can, but is not limited to, be implemented as a TPE (Thermoplastic Elastomer) part for water absorption and swelling. It is understood that the TPE part mentioned in this application can be composed of a variety of different polymer combinations and possess specific water absorption and swelling properties; this can be achieved by selecting appropriate matrix materials, introducing specific hydrophilic components or groups, and optimizing the formulation and processing technology. For example, the water absorption and swelling coefficient of the TPE part can be adjusted by selecting hydrophilic components with good coefficient properties or by introducing more hydrophilic groups through chemical modification.

[0041] Furthermore, the biodegradable coating 32 can, but is not limited to, be implemented as a PLLA (poly-L-lactic acid) component for biodegradation / enzymatic hydrolysis to break down into water and carbon dioxide. It is understood that the expandable body 31 mentioned in this application can also be prepared from other expandable materials, as long as it can absorb liquid and expand, and is biocompatible with the human body; the biodegradable coating 32 mentioned in this application can also be prepared from other biodegradable materials, as long as it can cover the expandable body 31 to isolate it from liquid.

[0042] Thus, when using the body fluid drainage stent 1, it can be placed endoscopically. For example, in an interventional operating room using a DSA (Digital Subtraction Angiography) machine. Guided by digital subtraction angiography (DSA), a duodenoscope is used to first reach the stomach through the esophagus and then the duodenal papilla. A retrograde catheter is inserted through the duodenoscope into the bile duct or pancreatic duct for angiography to determine the exact location of the obstruction. A suitable stent is selected and introduced into the obstruction site through the working channel of the endoscope, and released through a special release mechanism, completing the implantation of the stent body 10 of the fluid drainage stent 1. The traction wire 20 of the fluid drainage stent 1, along with the traction element 30, remains in the duodenum. Subsequently, as time progresses, the biodegradable coating 32 of the traction element 30 is gradually enzymatically decomposed into water and carbon dioxide in the intestine, exposing the expandable body 31 of the traction element 30, which absorbs water and expands in the intestine. Then, the expanded bulb, under the peristalsis of the intestine, pulls the traction wire 20 to pull the stent body 10 from the bile duct or pancreatic duct into the ileum and jejunum, and then out of the body through the anus. In other words, the body body 10 of the fluid drainage stent 1 of this application can be expelled from the body simply by the peristalsis of the intestine under the traction of the traction line 20 and the traction member 30, without the need for a second surgery, thus avoiding secondary harm to the patient and reducing the patient's pain and fear.

[0043] It is worth noting that the stent body 10 mentioned in this application can be a metal stent or a plastic stent. However, since self-expanding metal stents are usually porous structures made of non-degradable metal materials, granulation tissue can grow into the porous structure of the stent after long-term implantation, making the metal stent difficult to remove and unsuitable for treating benign stenosis; therefore, the stent body 10 of this application is preferably implemented as a plastic stent made of non-degradable plastic material, so as to reduce the difficulty of stent removal and reduce stent cost.

[0044] For example, such as Figures 1 to 4As shown, the stent body 10 may include an inner tube 11 with a drainage channel 110, an outer tube 12 fitted inside the inner tube 11, and a plurality of elastic arms 13 extending outwardly from the outer tube 12. Thus, when the stent body 10 is implanted into the bile duct or pancreatic duct, the elastic arms 13 open outward from the outer tube 12 to form barbed structures, thereby securely fixing the stent body 10 to the narrow part of the bile duct or pancreatic duct, allowing body fluids to normally enter and exit the bile duct or pancreatic duct through the drainage channel 110 of the inner tube 11.

[0045] Optionally, multiple flexible arms 13 are arranged opposite to each other at both ends of the outer tube 12 to more stably fix the stent body 10 to the obstruction site in the bile duct or pancreatic duct. For example, two flexible arms 13 are located at both ends of the outer tube 12 and are arranged opposite to each other on the left and right sides of the outer tube 12.

[0046] Optionally, the inner tube 11 is made of PTFE (Polytetrafluoroethylene) to provide a smooth drainage channel 110. This not only reduces the risk of infection by decreasing bacterial adhesion to the stent and prolonging the stent's normal lifespan, but also facilitates smoother flow of bodily fluids through the stent, increasing the drainage rate. It is understood that the inner tube mentioned in this application can also be made of other types of plastic tubing, which will not be elaborated upon here.

[0047] Optionally, such as Figure 2 and Figure 4 As shown, the outer tube 12 is integrally connected to the elastic arm 13. For example, the outer tube 12 and the elastic arm 13 are made of Pebax (nylon elastomer) to provide a smooth outer surface, which not only reduces bacterial adhesion to the stent and lowers the risk of infection, but also reduces friction and irritation to the cavity during stent implantation and removal, alleviating patient discomfort and reducing surgical difficulty. It is understood that the elastic arm 13 mentioned in this application may be a barb formed by first heating and shaping the outer wall of the Pebax tube and then cooling it to set, possessing a certain degree of elastic deformation capability.

[0048] Optionally, such as Figures 1 to 4 As shown, the inner tube 11 is fused to the outer tube 12, and one end of the traction wire 20 is fixedly connected between the inner tube 11 and the outer tube 12 to ensure that the other end of the traction wire 20 can extend into the duodenum from one end of the stent body 10. It is understood that in other examples of this application, both ends of the traction wire 20 can be fixedly connected between the inner tube 11 and the outer tube 12, so that the traction wire 20 forms a closed loop on the axial side of the stent body 10 to better restrain the traction member 30; or, the middle part of the traction wire 20 can be fixedly connected between the inner tube 11 and the outer tube 12, which will not be elaborated further in this application.

[0049] Optionally, the outer tube 12 has rounded ends to avoid damage to human tissue during implantation or removal from the body.

[0050] According to the above embodiments of this application, as Figure 2 As shown, the biodegradable coating 32 can be applied to the surface of the expandable body 31 to completely isolate the liquid and prevent the expandable body 31 from absorbing liquid and expanding when the stent body 10 is first implanted, which would prevent the stent body 10 from remaining in the narrow part of the bile duct or pancreatic duct for a certain period of time and thus fail to achieve the required fluid guidance effect.

[0051] In addition, such as Figure 1 and Figure 2 As shown, multiple traction components 30 can be connected in series at intervals on the traction line 20 so as to reserve expansion space for adjacent traction components 30 while being restrained by the traction line 20.

[0052] Optionally, such as Figure 2 As shown, the traction member 30 has a through hole 300 penetrating the expandable body 31. The inner diameter of the through hole 300 is larger than the diameter of the traction line 20, so that the traction member 30 can be threaded onto the traction line 20 to reduce the difficulty of binding.

[0053] Optionally, such as Figure 1 and Figure 2 As shown, the traction line 20 has a plurality of plugs 200 arranged at intervals, the outer diameter of the plugs 200 being larger than the inner diameter of the through holes 300, so as to securely fasten the traction member 30 to the traction line 20.

[0054] Optionally, such as Figure 3 and Figure 4 As shown, the plug 200 is implemented as a knot, and the distance between two adjacent knots is greater than or equal to the expansion diameter of the expandable body 31, to prevent the knot from blocking the expansion body 31 from absorbing liquid and expanding, and to avoid damaging the expansion body 31. It is understood that the expansion diameter mentioned in this application refers to the diameter of the expansion body 31 after it has completed absorbing liquid and expanding.

[0055] It is worth noting that the knot mentioned in this application is formed by knotting the traction line 20, which helps to reduce the difficulty of binding the traction member 30. Of course, in other examples of this application, the plug 200 can also be implemented as a block fixed on the traction line 20, as long as it can bind the traction member 30 to the traction line 20, which will not be elaborated further in this application.

[0056] Furthermore, in the above embodiments of this application, the expandable body 31 can be implemented as an expandable sphere 311 so that the traction member 30 is implemented as a traction ball.

[0057] Optionally, the expansion coefficient of the expandable body 31 is between 50 and 100. This ensures that the expandable body 31 has a small volume before expansion to avoid being affected by intestinal peristalsis and causing adverse nutrition to the intestines, and also ensures that the expandable body 31 has a large volume after expansion so as to forcefully pull the traction line 20 under intestinal peristalsis. For example, the diameter of the traction member 30 can be between 2 mm and 3.5 mm; the expansion diameter of the expandable body 31 can be between 10 mm and 20 mm.

[0058] Optionally, the expansion diameter of the expandable body 31 is larger than the maximum radial dimension of the support body 10, which facilitates better traction of the support body 10 to expel it from the body. It is understood that the maximum radial dimension mentioned in this application may refer to the maximum distance between the two relatively arranged elastic arms 13.

[0059] It is worth noting that, since the traction member 30 in the above embodiments of this application is implemented as a traction ball, there is a possibility that one traction ball may get stuck between two traction balls in the body; therefore, in order to reduce the risk of multiple traction members 30 getting stuck together, this application further provides a modified example of a body fluid drainage stent. Specifically, compared with the above embodiments according to this application, the body fluid drainage stent 1 of the modified example of this application differs in that: Figure 5 and Figure 6 As shown, the expandable body 31 can be implemented as an expandable column 312 so that the traction member 30 is implemented as a traction column; that is, the traction member 30 of this application is designed as a columnar traction body, which can avoid the situation where multiple traction columns get stuck together during intestinal peristalsis.

[0060] It is understood that in other examples of this application, the expandable body 31 may also be implemented as other shapes such as cones or cubes, which will not be elaborated upon here.

[0061] The technical features of the above embodiments can be combined without changing the basic principle of this utility model. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are quite specific and detailed. However, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A body fluid drainage stent, characterized in that, include: The main body of the stent is used to place it into the bile duct or pancreatic duct; A traction wire, fixedly connected to one end of the main body of the support, is used to extend into the duodenum; as well as One or more traction components, including an expandable body bound to the traction line and a biodegradable coating covering the expandable body; when the biodegradable coating is degraded to expose the expandable body, the expandable body absorbs liquid and expands to drive the traction line under intestinal peristalsis to pull the stent body outside the body.

2. The body fluid drainage stent according to claim 1, characterized in that, The expandable body is a TPE component; the biodegradable coating is a PLLA component.

3. The body fluid drainage stent according to claim 1, characterized in that, The coefficient of expansion of the expandable body is between 50 and 100.

4. The body fluid drainage stent according to claim 1, characterized in that, Multiple traction elements are connected in series at intervals on the traction line; each traction element has a through hole penetrating the expandable body, the inner diameter of which is larger than the diameter of the traction line.

5. The body fluid drainage stent according to claim 4, characterized in that, The traction line has multiple plugs arranged at intervals, the outer diameter of the plugs being larger than the inner diameter of the through holes; the plugs are wire knots, and the distance between two adjacent wire knots is greater than or equal to the expansion diameter of the expandable body.

6. The body fluid drainage stent according to claim 1, characterized in that, The diameter of the traction component is between 2 mm and 3.5 mm; the expansion diameter of the expandable body is between 10 mm and 20 mm.

7. The body fluid drainage stent according to any one of claims 1 to 6, characterized in that, The main body of the support includes an inner tube with a drainage channel, an outer tube fitted inside the inner tube, and a plurality of elastic arms extending outwardly from the inner tube; the plurality of elastic arms are arranged opposite to each other at both ends of the outer tube.

8. The body fluid drainage stent according to claim 7, characterized in that, The inner tube is made of PTFE; the outer tube and the elastic arm are made of Pebax; the inner tube is fused to the outer tube, and the traction line is fixedly connected between the inner tube and the outer tube.

9. The body fluid drainage stent according to any one of claims 1 to 6, characterized in that, The main body of the support is a metal support or a plastic support.

10. The body fluid drainage stent according to any one of claims 1 to 6, characterized in that, The expandable body is an expandable sphere or an expandable cylinder.

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