A stent for TIPS surgery

Abstract

The present invention relates to a stent for TIPS surgery, comprising a first stent body and a second stent body. When in use, the first stent body is sleeved on the outside of the second stent body to control the self-expansion range of the second stent body; the first stent body comprises a first connector, an intermediate connector and a second connector; the second stent body is woven from a single-filament memory alloy, and the second stent body comprises a first section and a second section connected to each other, the first section is a woven spiral structure, and the second section is a woven self-locking structure. The first stent body is arranged as the first connector, the intermediate connector and the second connector, so that the first stent body can be shortened to a small extent in the length direction when expanding, and through the design of the structure, the stainless steel material or the cobalt-chromium alloy material is used to facilitate mechanical diameter regulation, and under physiological conditions, creep will not occur for a long time, which effectively improves the stability of the stent for TIPS surgery.

Description

Technical Field

[0001] The invention belongs to the technical field of medical devices, and in particular relates to a pressure-dividing stent for TIPS. Background Art

[0002] Portal hypertension refers to a disease characterized by obstruction of portal vein blood flow, blood stasis and increased pressure, leading to a series of clinical manifestations such as splenomegaly, hypersplenism, esophageal-gastric varices, hematemesis, ascites, etc. Transjugular intrahepatic portosystemic shunt (TIPS) is an interventional treatment for portal hypertension and is gradually becoming the main clinical method. TIPS surgery is to establish an artificial channel for blood shunting between the intrahepatic portal vein and the hepatic vein through interventional surgery, connect the high-pressure portal vein with the hepatic vein, shunt part of the portal vein blood, and achieve the purpose of reducing portal hypertension, controlling and preventing esophageal varicose vein rupture and bleeding, and promoting ascites absorption.

[0003] However, TIPS surgery has its limitations in scope of use, and the risk of hepatic encephalopathy still restricts the promotion and use of TIPS surgery. The increased incidence of hepatic encephalopathy is because during TIPS surgery, due to the establishment of a shunt channel, the nitrogen-containing substances in the blood directly enter the systemic circulation without being detoxified by the liver, resulting in increased blood ammonia. The increase in blood ammonia concentration causes an imbalance of excitatory and inhibitory neurotransmitters in the brain, which manifests as mental excitement or inhibition. Therefore, the size of the shunt channel has a certain relationship with the risk of hepatic encephalopathy. The larger the shunt channel, the more likely it is to develop hepatic encephalopathy. However, if the shunt channel is too small, insufficient portal vein pressure relief may still cause esophageal gastric vein rupture and bleeding again. Therefore, people need a stent that can flexibly adjust the size of the shunt channel during or after surgery, so that the size of the shunt channel can be reasonably controlled according to actual conditions, while reducing portal hypertension and effectively reducing the risk of hepatic encephalopathy. Summary of the invention

[0004] In view of this, the present invention provides a stent for TIPS surgery.

[0005] The technical solution adopted by the present invention is:

[0006] A stent for TIPS surgery, comprising a first stent body and a second stent body, wherein the first stent body is sleeved outside the second stent body to control the self-expansion range of the second stent body during use;

[0007] The first bracket body includes a first connector, an intermediate connector and a second connector. The number of the first connectors is two, which are respectively located at the two ends of the first bracket body; the first connector and the second connector, as well as two adjacent second connectors, are connected by the intermediate connector respectively; the intermediate connector is an N-shaped structure; the first connector and the second connector are both ring-shaped units connected end to end, and any one of the W-shaped units of the first connector includes a connection point with the intermediate connector; any one of the W-shaped units of the second connector includes two connection points with the intermediate connector, and the two connection points are respectively located on the upper and lower sides of the W-shaped unit;

[0008] The second stent body is woven from a single-filament memory alloy, and includes a first section and a second section connected to each other, the first section is a woven spiral structure, the second section is a woven self-locking structure, and a coating structure is provided on the first section; the coating structure of the first section includes an inner coating layer, an intermediate layer and an outer coating layer, and the inner coating layer is made of at least two layers of coating materials.

[0009] According to a further optimization of the technical solution of the present invention, the first stent body is made of a stainless steel material or a cobalt-chromium alloy material, and the second stent body is woven from a single nickel-titanium alloy wire.

[0010] According to a further optimization of the technical solution of the present invention, the inner coating layer and the outer coating layer are both made of expanded polytetrafluoroethylene material, and the middle layer is made of fluorinated ethylene propylene.

[0011] According to a further optimization of the technical solution of the present invention, the length of the first section accounts for 50%-90% of the overall length, and the length of the first bracket body is 40%-75% of the length of the first section.

[0012] In a further optimization of the technical solution of the present invention, the intermediate layer is arranged on the first section of the second bracket body by a hot melt or bonding process.

[0013] Beneficial effects of the present invention:

[0014] The first stent body is configured as a first connector, an intermediate connector and a second connector, so that the first stent body can be shortened to a small extent in the length direction when expanded, and the shortening degree can be almost ignored. In addition, through the design of the structure, its stainless steel material or cobalt-chromium alloy material is used to facilitate mechanical diameter regulation, and under physiological conditions, creep will not occur for a long time, thereby effectively improving the stability of the stent used for TIPS surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0016] Figure 1 This is a schematic diagram of the structure of the stent used in TIPS surgery when it is in use;

[0017] Figure 2 is a schematic structural diagram of a first bracket body;

[0018] Figure 3 is a structural schematic diagram of the introduction of the first bracket body;

[0019] Figure 4 It is a structural schematic diagram of the second bracket body.

[0020] In the figure: A, portal vein; B, hepatic vein; C, intrahepatic puncture;

[0021] 1. First bracket body; 11. First connecting body; 12. Intermediate connecting body; 13. Second connecting body;

[0022] 2. Second bracket body; 21. First section; 22. Second section. DETAILED DESCRIPTION

[0023] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. In order to avoid confusing the essence of the present invention, known methods, processes, procedures, and components are not described in detail.

[0024] In addition, persons of ordinary skill in the art will appreciate that the drawings provided herein are for illustration purposes and are not necessarily drawn to scale.

[0025] Unless the context clearly requires otherwise, throughout the specification and claims, the words "include", "comprising" and similar words should be interpreted in an inclusive sense rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to".

[0026] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0027] See also Figure 1-Figure 4The present invention provides a stent for TIPS surgery, including a first stent body 1 and a second stent body 2. After being unfolded, the first stent body 1 and the second stent body 2 are both hollow tubular structures. When in use, the first stent body 1 is sleeved on the outside of the second stent body 2. The second stent body 2 is a self-expanding stent that can expand to a maximum diameter after being released. The first stent body 1 is expanded under the action of an external force. When expanded to a required diameter, it is used to limit the self-expansion range of the second stent body 2. The stent for TIPS surgery mainly acts on the shunt channel formed by intrahepatic puncture, shunting part of the portal vein blood to the hepatic vein to reduce the high pressure of the portal vein. However, since the ammonia content of the blood in the hepatic vein can cause hepatic encephalopathy, a stable and flexible mechanically controlled stent for TIPS surgery is required.

[0028] In the present technical solution, the first bracket body 1 is designed to be composed of three parts: a first connector 11, an intermediate connector 12 and a second connector 13. There are two first connectors 11, which are respectively located at the two ends of the first bracket body 1; the first connector 11 and the second connector 13, as well as two adjacent second connectors 13, are respectively connected by the intermediate connector 12; the intermediate connector 12 is an N-shaped structure, which can increase the straight line space and ensure the effective length of the diversion channel to the greatest extent; the first connector 11 and the second connector 13 are both ring-shaped with several W-shaped units connected end to end, and any one of the W-shaped units of the first connector includes a connection point 14 with the intermediate connector 12; any one of the W-shaped units of the second connector 13 includes two connection points 14 with the intermediate connector 12, and the two connection points 14 are respectively located on the upper and lower sides of the W-shaped unit. By setting the connection points 14 and the shape, the first stent body 1 can be shortened to a small extent in the length direction when expanded, and the degree of shortening can be almost ignored. In addition, through the design of the structure, the stainless steel material or cobalt-chromium alloy material is used to facilitate mechanical diameter adjustment, and under physiological conditions, creep will not occur for a long time, thereby effectively improving the stability of the stent used for TIPS surgery.

[0029] It should be noted that the first bracket body 1 is made of stainless steel or cobalt-chromium alloy by laser cutting. Laser cutting can increase the stability of the first bracket body 1 and ensure that the first bracket body 1 is an integral structure, thereby ensuring its mechanical properties.

[0030] The second stent body 2 is woven from a single-filament memory alloy. By selecting a single wire, it can be wound to the distal end of the uncoated section and then returned to the junction of the coated section and the uncoated section, effectively preventing the loose wire head from being exposed to the outside of the stent, which may cause safety hazards during long-term use under a physiological environment. Preferably, the second stent body 2 is woven from nickel-titanium alloy wire. The second stent body 2 includes a first section 21 and a second section 22 connected to each other. The first section 21 is a woven spiral structure. By setting it into a spiral structure with alternating crests and troughs, the first section 21 of the second stent body 2 can be made more flexible. The second section 22 is a woven self-locking structure or a door-locking structure, which can prevent the second section 22 from excessively stretching in the overall longitudinal direction. A coating structure is provided on the first section 21, and the coating structure of the first section 21 includes an inner coating layer, an intermediate layer and an outer coating layer, wherein the inner coating layer is made of at least two layers of coating materials, and is connected to the woven mesh of the first section 21 through the coating materials, so as to reduce the permeability of bile while ensuring flexibility and longitudinal strength. Preferably, the inner coating layer and the outer coating layer are both made of expanded polytetrafluoroethylene material, and the intermediate layer is fluorinated ethylene propylene.

[0031] Preferably, the length of the first section 21 accounts for 50%-90% of its overall length, and the length of the first bracket body 1 is 40%-75% of the length of the first section 21. This structural setting enables stable pressure division.

[0032] Preferably, the intermediate layer is sewed to the first section 21 of the second stent body 2, and the sewed connection can increase the stability of the coating. It can also be set on the first section of the second stent body by using a hot melt or bonding process.

[0033] When using the stent for TIPS surgery, the first stent body 1 is first introduced into the intrahepatic puncture site through the introduction system, and then a suitable support balloon is selected to support the inner diameter of the first stent body 1 to the first diameter (the minimum diameter expanded by flow calculation), and then the second stent body 2 is introduced, so that the second stent body 2 is expanded in the first stent body 1 until it is fully expanded. During the introduction, the second section 22 of the second stent body 2 can extend out of the intrahepatic puncture channel to complete the initial introduction. It should be noted that after the introduction is completed, at least one pressure measurement is performed to determine the pressure gradient between the portal vein and the hepatic vein or the inferior vena cava. According to the pressure situation, the diameter size of the first stent body 1 can be adjusted accordingly. Of course, multiple pressure measurements can also be performed and the diameter of the first stent body 1 can be adjusted. For example, the pressure can be measured one day, one week, one month or longer after the operation is completed, and the diameter of the first stent body 1 can be adjusted according to the measurement results.

[0034] The inner diameter (ID) of the first stent body 1 is about 6 mm when deployed and can expand to about 10 mm. In some examples, the inner diameter of the first stent body 1 can normally expand by 12% to 40%. Of course, the structure of the first stent body 1 designed in this technical solution can expand by 40%-70% and remain stable within this range. The length of the second stent body 2 is 6cm-12cm, and the total wall thickness is between 0.1mm-1mm.

[0035] It should be understood that the above-mentioned embodiments are merely illustrative and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by those skilled in the art to the above-mentioned details will all be included in the scope of the claims of the present invention.

Claims

1. A stent for TIPS surgery, characterized in that: It comprises a first stent body and a second stent body, wherein the first stent body is sleeved on the outside of the second stent body to control the self-expansion range of the second stent body when in use; The first bracket body includes a first connector, an intermediate connector and a second connector. The number of the first connectors is two, which are respectively located at the two ends of the first bracket body; the first connector and the second connector, as well as two adjacent second connectors, are connected by the intermediate connector respectively; the intermediate connector is an N-shaped structure parallel to the axis of the first bracket body; the first connector and the second connector are both ring-shaped with a number of W-shaped units connected end to end, and any one of the W-shaped units of the first connector includes a connection point with the intermediate connector; any one of the W-shaped units of the second connector includes two connection points with the intermediate connector, and the two connection points are respectively located on the upper and lower sides of the W-shaped unit; The second stent body is woven from a single-filament memory alloy, and includes a first section and a second section connected to each other, the first section is a woven spiral structure, the second section is a woven self-locking structure, and a coating structure is provided on the first section; the coating structure of the first section includes an inner coating layer, an intermediate layer and an outer coating layer, and the inner coating layer is made of at least two layers of coating materials.

2. The stent for TIPS surgery according to claim 1, characterized in that: The first stent body is made of stainless steel or cobalt-chromium alloy, and the second stent body is woven from a single nickel-titanium alloy wire.

3. The stent for TIPS surgery according to claim 1, characterized in that: The inner coating layer and the outer coating layer are both made of expanded polytetrafluoroethylene material, and the middle layer is made of fluorinated ethylene propylene.

4. The stent for TIPS surgery according to claim 1, characterized in that: The length of the first bracket body is 40%-75% of the length of the first section.

5. The stent for TIPS surgery according to claim 1, characterized in that: The intermediate layer is arranged on the first section of the second bracket body by a hot-melt or bonding process.

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