Biliary stent for inhibiting scarring and endothelial proliferation

Abstract

A biliary tract stent for inhibiting scar and endothelial proliferation comprises a left segment and a right segment, characterized in that: an intermediate segment is arranged between the left segment and the right segment, the left segment, the right segment and the intermediate segment are all mesh structures, the intermediate segment is a retracted type, so that the overall structure of the biliary tract stent is slightly smaller in the middle and larger at both ends; the intermediate segment is provided with a treatment layer, which is used to inhibit scar and endothelial proliferation; the technical scheme of the application adopts the synergistic effect of radiotherapy and mechanical support to accurately inhibit fibroblast proliferation at the stenosis site of the biliary tract anastomotic mouth, inhibit scar and reduce endothelial proliferation, solves the problem of repeated restenosis after traditional stent implantation, and greatly prolongs the patency time of the stent.

Description

Technical Field

[0001] This utility model relates to a biliary stent, and more particularly to a biliary stent that inhibits scarring and endothelial hyperplasia. Background Technology

[0002] A biliary stent is a medical device used to treat biliary obstruction. It is inserted into the narrowed or blocked bile duct to restore bile drainage, thereby relieving symptoms such as jaundice, itching, and cholangitis. Based on the material, they are mainly divided into metal stents and plastic stents: metal stents have a larger diameter and a longer patency period (approximately 6-12 months), suitable for patients with malignant obstruction or a longer expected survival; plastic stents are less expensive and replaceable, but are prone to blockage (average patency period 3-6 months), and are mostly used for benign strictures or short-term treatment.

[0003] Currently, when using biliary stents to treat post-operative scar strictures at bile duct anastomosis sites, DSA fluoroscopy is typically used to identify the stricture segment of the bile duct anastomosis, and then the stent is released using balloon inflation. However, due to mechanical stimulation at both ends of the stent, scarring and endothelial hyperplasia can easily occur, leading to bile duct restenosis.

[0004] To address the above issues, we provide a biliary stent that inhibits scarring and endothelial hyperplasia. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a biliary stent that inhibits scarring and endothelial hyperplasia.

[0006] The purpose of this utility model is achieved as follows:

[0007] A biliary stent that inhibits scarring and endothelial hyperplasia includes a left segment and a right segment, with a middle segment disposed between the left segment and the right segment. The left segment, the right segment, and the middle segment are all mesh structures, and the middle segment is concave, so that the biliary stent as a whole has a structure that is small in the middle and large at both ends.

[0008] The intermediate section is provided with a treatment layer, which is used to inhibit scarring and endothelial hyperplasia.

[0009] Furthermore, the outer surface of the middle section is provided with a groove that is adapted to the treatment layer, and the treatment layer is embedded in the groove.

[0010] Furthermore, the treatment layer is covered on the outer wall of the intermediate section.

[0011] Furthermore, the left and right segments are provided with a preventive layer, which is used to inhibit scarring and endothelial hyperplasia.

[0012] Furthermore, the longitudinal section of the middle segment has a concave arc-shaped side.

[0013] Furthermore, the middle section has a mesh density greater than that of the left and right sections.

[0014] Furthermore, the length of the left segment and the right segment is 0.5cm.

[0015] Furthermore, the length of the intermediate segment is 0.5-1cm.

[0016] Furthermore, both the left and right sides are provided with an external frame.

[0017] Furthermore, the outer frame comprises several support rods, which are equally spaced around the left side section and the right side section.

[0018] Advantages of this utility model:

[0019] 1. The technical solution of this application, through the design of the inward indentation of the middle section, can prevent the support from shifting.

[0020] 2. By combining radiotherapy with mechanical support, the proliferation of fibroblasts in the stenotic area is precisely inhibited, scarring is suppressed, and endothelial hyperplasia is reduced. This solves the problem of repeated restenosis after traditional stent placement and greatly prolongs the patency time of the stent. Attached Figure Description

[0021] Figure 1 A schematic diagram of a biliary stent structure that inhibits scarring and endothelial hyperplasia. Figure 1 .

[0022] Figure 2 A schematic diagram of a biliary stent structure that inhibits scarring and endothelial hyperplasia. Figure 2 .

[0023] In the diagram: 1. Left side segment, 2. Right side segment, 3. Middle segment, 4. Treatment layer, 5. Prevention layer, 6. Exoskeleton. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0025] This application provides a biliary stent that inhibits scarring and endothelial hyperplasia.

[0026] Example 1, such as Figure 1-2 As shown.

[0027] A biliary stent for inhibiting scarring and endothelial hyperplasia includes a left segment 1 and a right segment 2, both of which are cylindrical tubular structures. The left segment 1 and right segment 2 are preferably 0.5 cm in length. A middle segment 3 is disposed between the left segment 1 and the right segment 2, and the middle segment 3 is preferably 0.5-1 cm in length. The left segment 1, right segment 2, and middle segment 3 are all mesh structures. The biliary stent of this application is a short stent with a total length of 1.5-2.5 cm. During stent placement, balloon dilation ensures that the dense mesh segment precisely covers the center of the stenosis, so that the middle segment 3 of the biliary stent is located precisely at the center of the stenosis, better supporting the bile duct and resolving stenosis and blockage problems. The left segment 1, right segment 2, and middle segment 3 are all made of absorbable material.

[0028] The middle section 3 is recessed, and the longitudinal section of the middle section 3 has an inwardly concave arc-shaped structure on its side. That is, the middle section 3 is a rotating structure with a vertically concave arc-shaped groove around a vertical line.

[0029] The left segment 1, the middle segment 3, and the posterior segment are connected in sequence, giving the biliary stent an overall structure that is smaller in the middle and larger at both ends. This structure allows for better fixation of the stent when the center of the biliary stricture is located in the middle segment 3, and the larger ends can keep the stricture within the middle segment 3, preventing the biliary stent from dislodging from the stricture.

[0030] The middle segment 3 is provided with a treatment layer 4, which is used to inhibit scarring and endothelial hyperplasia. The left segment 1 and the right segment 2 are provided with a preventive layer 5, which is used to inhibit scarring and endothelial hyperplasia. Both the treatment layer 4 and the preventive layer 5 preferably use strontium-90 radioactive element for radiotherapy. Strontium-90 releases beta rays (maximum energy 0.546 MeV, tissue penetration depth 2-3 mm), wherein the dose of strontium-90 carried by the treatment layer 4 is greater than that of the preventive layer 5. The high dose of the treatment layer 4 can precisely inhibit fibroblast proliferation in the narrowed area, reducing scarring and endothelial hyperplasia. The low dose of the preventive layer 5 can reduce tissue contact and avoid the risk of radiation enteritis / cholangitis.

[0031] Strontium 90 can be integrated in various ways, so that the treatment layer 4 and the prevention layer 5 carry Strontium 90.

[0032] 1. Microsphere embedding. The outer surface of the middle section 3 is provided with a groove that is adapted to the treatment layer, and the treatment layer is embedded in the groove.

[0033] The treatment layer consists of several microspheres, with Strontium 90 encapsulated within biocompatible microspheres (such as PLGA). The treatment layer is then embedded into a groove on the surface of the intermediate segment 3.

[0034] 2. Surface coating. The treatment layer is covered on the outer wall of the intermediate section 3.

[0035] The strontium 90 compound is mixed with a biocompatible material (such as polyurethane, silicone, or calcium phosphate) to form the treatment layer. The treatment layer is then attached to the middle section surface via a spraying, electrophoretic deposition, or impregnation process.

[0036] The preventive layer 5 and the treatment layer 4 are manufactured using the same process steps. The only difference is that the Sr90 dose in the preventive layer 5 is less than that in the treatment layer 4.

[0037] The middle section 3 has a higher mesh density than the left section 1 and the right section 2. By adjusting the mesh density, the dose of strontium 90 can be controlled, so that the dose of strontium 90 in the preventive layer 5 is lower than the dose in the therapeutic layer 4.

[0038] The left segment 1, the right segment 2, and the middle segment 3 are all made of absorbable material. Both the left segment 1 and the right segment 2 are externally fitted with an exoskeleton 6. This biliary stent design, using absorbable material and in conjunction with the exoskeleton 6, is an innovative design that combines temporary support with long-term structural maintenance. This design aims to address early mechanical support needs through phased functional implementation, while also promoting tissue regeneration and reducing complications from long-term foreign body retention.

[0039] The outer frame 6 comprises several support rods, which are evenly spaced around the left side section 1 and the right side section 2. After the support is inserted for a period of time, the support gradually degrades, while the outer frame 6 gradually becomes internally solidified.

[0040] When using this utility model:

[0041] The guidewire is guided to the biliary stricture using an endoscope (such as ERCP) or percutaneous transluminal catheterization (PTCD). A balloon catheter is then inserted along the guidewire to the target location. A biliary stent is placed around the outside of the balloon. The balloon is slowly inflated to dilate the stricture. The stent is fully deployed and adheres to the bile wall to ensure unobstructed bile drainage. The balloon and guidewire are then withdrawn.

[0042] It should be noted that, in this document, relational terms such as “first” and “second” are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0043] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the claims. It should be understood that this application is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A biliary stent for inhibiting scarring and endothelial hyperplasia, comprising a left segment and a right segment, characterized in that: A middle section is provided between the left side segment and the right side segment. The left side segment, the right side segment, and the middle section are all mesh structures. The middle section is inwardly recessed, so that the biliary stent as a whole has a structure that is small in the middle and large at both ends. The intermediate section is provided with a treatment layer, which is used to inhibit scarring and endothelial hyperplasia.

2. The biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: The outer surface of the middle section has a groove adapted to the treatment layer, and the treatment layer is embedded in the groove.

3. The biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: The treatment layer is covered on the outer wall of the middle section.

4. The biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: The left and right segments are provided with a preventive layer, which is used to inhibit scarring and endothelial hyperplasia.

5. A biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: The longitudinal section of the middle segment has an inwardly concave arc-shaped structure on its sides.

6. The biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: The middle section has a mesh density greater than that of the left and right sections.

7. The biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: The length of the left segment and the right segment is 0.5cm.

8. A biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: The length of the middle section is 0.5-1cm.

9. A biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 1, characterized in that: Both the left and right sections are provided with an external frame.

10. A biliary stent for inhibiting scarring and endothelial hyperplasia according to claim 9, characterized in that: The outer frame consists of several support poles, which are evenly spaced around the left side section and the right side section.

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