A fistula implant

Abstract

The present invention discloses a fistula implant, comprising: a spiral body and an expansion body connected to each other, one end of the spiral body being an implantation end and the other end being a connection end; the expansion body is a cone formed by a plurality of expansion sheets, the connection of the plurality of expansion sheets forming the proximal end of the expansion body, the connection end being fixedly connected to the proximal end and not intercommunication; the Young's modulus of the fistula implant is 400-3000MPa, the shear modulus is 150-1200Mpa, and the Poisson's ratio is 0.3-0.4. The present invention provides a fistula implant, which can ensure the blocking effect after implantation, prevent secondary leakage, and avoid the pain caused by blocking, thereby improving comfort.

Description

Technical Field

[0001] The invention belongs to the field of medical devices, and in particular relates to a fistula implant. Background Art

[0002] Anal fistula is an abnormal infected fistula between the anorectum and the skin around the anus. It is usually caused by an infection of the anal crypt glands and is formed after the abscess ruptures or incision and drainage. The symptoms of anal fistula include repeated discharge of purulent secretions or feces from the external opening. The skin around the anus may become thickened and red, and sometimes gas is discharged from the external opening. Surgery is usually required to treat anal fistula. There are various surgical methods, including anal fistula incision, resection, anal fistula enucleation, anal fistula hanging thread therapy, etc. The choice of surgery should be based on whether the anal fistula involves the anal sphincter or how much it involves.

[0003] In order to provide a non-destructive treatment for perianal fistulas, many doctors have tried to use implants to block perianal fistulas in recent years. However, conventional implants are painful because they are entangled with the tissues in the fistula to form a seal, and they are also easily squeezed out of the duct and fail, allowing feces to enter the duct and cause reinfection, abscess formation and secondary fistula surgery.

[0004] Therefore, providing a fistula implant that ensures the blocking effect while improving its comfort is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The present invention provides a fistula implant, which can ensure the blocking effect after implantation, prevent secondary leakage, avoid the pain caused by blocking, and improve the comfort.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is: a fistula implant, comprising: a spiral body and an expansion body connected to each other, one end of the spiral body is an implantation end, and the other end is a connecting end; the expansion body is a cone formed by a plurality of expansion sheets, the connection between the plurality of expansion sheets constitutes the proximal end of the expansion body, and the connecting end is fixedly connected to the proximal end and is not interconnected; the Young's modulus of the fistula implant is 400~3000MPa, the shear modulus is 150~1200Mpa, and the Poisson's ratio is 0.3~0.4.

[0007] Furthermore, the inner diameter of the spiral body decreases along the direction from the implantation end to the connection end.

[0008] Furthermore, the outer diameter of the spiral body is the same along the length direction between the connecting end and the implantation end.

[0009] Furthermore, an anti-rewinding structure is arranged on the periphery of the spiral.

[0010] Furthermore, the anti-return structure is a convex structure, and the convex structure includes one or more of a barb, a barb, an arrow or a fishhook-shaped structure.

[0011] Furthermore, the anti-return structure is a concave structure, and the concave structure includes a groove or a groove.

[0012] Furthermore, ridges are arranged on the outer surface of the expansion piece.

[0013] Furthermore, the fistula implant is made of an absorbable polymer formed by polymerization of lactide monomers and other monomers.

[0014] Furthermore, the lactide monomers include one or both of lactide and glycolide, and the other monomers include one or more of trimethylene carbonate, caprolactone or p-dioxanone.

[0015] Furthermore, the mass fraction of the lipid monomers is 50% to 90%, and the mass fraction of the other monomers is 10% to 50%.

[0016] Beneficial effects of the present invention: The present invention provides a fistula implant, which combines a spiral body with an expansion body, the spiral body is used for front-end implantation, and the expansion body is used for rear-end expansion and fixation, so as to avoid the problem of the implant falling out and becoming ineffective after implantation; the connection between the spiral body and the expansion body is a closed structure, which can effectively prevent feces in the rectum from entering the duct and causing reinfection, abscess formation and secondary fistula surgery; the expansion body is used for fixation, so as to avoid excessive entanglement of the spiral body with soft tissue and cause pain, and the implant made of an absorbable material with a certain elasticity can better adapt to the environment inside the fistula after implantation, fit more closely, and has appropriate softness, is easy to process and shape and maintains its shape, and will not be too soft to cause poor sealing and easy falling out after implantation, nor will it be too hard to cause pain after implantation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an overall structural diagram of the fistula implant of the present invention;

[0018] Figure 2 This is an end view of the expansion body of the fistula implant of the present invention.

[0019] Reference numerals include: 100 — fistula implant 110 — spiral body 120 — expansion body 111 — implant end 112 — connection end 113 — anti-return structure 121 — expansion sheet 122 — ridge 123 — proximal end 124 — distal end DETAILED DESCRIPTION

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0022] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship 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 orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0024] like Figure 1 and Figure 2As shown, the present invention provides a fistula implant 100, which mainly includes a spiral body 110 and an expansion body 120 connected to each other. One end of the spiral body 110 is an implantation end 111, which is used to be implanted into the fistula end during surgery; the other end is a connection end 112, which is used to connect and fix the expansion body 120. The expansion body 120 is surrounded by multiple expansion sheets 121 to form a cone shape, and the connection of the multiple expansion sheets 121 constitutes the proximal end 123 of the expansion body 120, which is used to be fixedly connected to the connection end 112 of the spiral body 110. The joint between the proximal end 123 and the connection end 112 is a closed end, so that the hollow structure of the spiral body 110 is not connected to the hollow structure of the expansion body 120, so as to prevent the feces in the rectum from flowing into the fistula again. The end of the expansion body 120 that can expand outward constitutes its distal end 124. The distal end 124 can expand outward after being implanted in the fistula, and abut against the inner wall of the fistula to fix the fistula implant 100 and avoid loosening or detachment due to external force. A ridge 122 is provided on the outer wall of the expansion sheet 121. The ridge 122 is used to act on the surrounding tissue when the expansion sheet 121 expands outward after implantation, so as to improve adhesion and avoid the slippage of the expansion body 120. The structure of the combination of the spiral body 110 and the expansion body 120 is adopted, and the spiral body 110 is used for front-end implantation; the expansion body 120 is used for fixing the rear end to prevent the fistula implant 100 from slipping or detaching and failure, and also reduce the pain caused by excessive entanglement of the spiral body 110 with the surrounding tissue.

[0025] The implant end 111 of the spiral body 110 has a cut tip for inserting and passing through the bulk of tissue around the fistula during implantation. An anti-return structure 113 is provided on the periphery of the spiral body 110. The anti-return structure 113 may be a convex structure, such as a barb, a barb, an arrow or a fishhook-shaped structure; the anti-return structure 113 may also be a concave structure, such as a groove, a notch or a groove. The surface of the anti-return structure 113 is roughened to increase friction and prevent return during implantation or post-migration after implantation. The cross-section of the spiral body 110 may be one or more of a circular, elliptical, triangular or polygonal shape.

[0026] The spiral body 110 of the implant includes a substantially constant outer diameter and an inner diameter that gradually decreases from the implant end 111 to the connection end 112. The implant end 111 of the implant surrounds the tissue in the fistula, and as the fistula implant 100 is advanced, the subsequent spiral structures provide anchoring and compression functions, and the smallest inner diameter toward the connection end 112 provides the maximum tissue compression energy. This structural design plays a good fixing and sealing role, preventing the passed feces from entering the fistula, thereby preventing re-infection.

[0027] The fistula implant 100 of the present invention is made of an absorbable biomedical high molecular polymer material, which can be polydioxanone, or a polymer formed by polymerizing one or two monomers of lactide and glycolide, or a polymer formed by polymerizing lactide monomers and other monomers, wherein the lactide monomers include one or two of lactide and glycolide, and the other monomers include one or more of trimethylene carbonate, caprolactone, and dioxanone, and the mass fraction of the lactide monomers is 50% to 90%, and the mass fraction of the other monomers is 10% to 50%. The fistula implant 100 made of the above materials meets the requirements of Young's modulus of 400 to 3000 MPa, shear modulus of 150 to 1200 MPa, and Poisson's ratio of 0.3 to 0.4. The elastic modulus of the fistula implant 100 is much higher than that of the skin and muscle (generally between a few tenths of a megapascal and tens of megapascals), so that it can better fit the surrounding tissues when implanted and achieve a good blocking effect. A certain shear modulus makes the material easy to process and shape and maintain its shape. The appropriate Poisson's ratio makes the implant have good shape stability after being subjected to force. The Poisson's ratio of the skin is within this range, and the Poisson's ratio of the skin is affected by the direction of the collagen fibers. When the skin is stretched perpendicular to the skin tension line (STL), the Poisson's ratio is about 0.36±0.05, and the Poisson's ratio of the muscle is generally 0.48. The Poisson's ratio equivalent to that of the surrounding tissues enables the implant to deform synchronously with the surrounding human tissues when subjected to external forces after implantation, and will not loosen or excessively invade the tissues to cause pain due to excessive deformation differences.

[0028] The fistula implant 100 product with satisfactory characteristics is made of suitable materials, so that the implant has suitable softness, is easy to process and shape and maintains its shape, is not too soft to cause poor sealing after implantation and is easy to fall out, and is not too hard to cause pain after implantation.

[0029] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present invention. As long as these changes do not deviate from the concept of the present invention, they all belong to the protection scope of the present invention.

Claims

1. A fistula implant, characterized in that: include: A spiral body (110) and an expansion body (120) are connected to each other, one end of the spiral body (110) is an implantation end (111), and the other end is a connection end (112); the expansion body (120) is a cone formed by a plurality of expansion sheets (121), the connection between the plurality of expansion sheets (121) forms a proximal end (123) of the expansion body (120), and the connection end (112) and the proximal end (123) are fixedly connected and not intercommunication; the Young's modulus of the fistula implant is 400-3000 MPa, the shear modulus is 150-1200 MPa, and the Poisson's ratio is 0.3-0.

4.

2. The fistula implant according to claim 1, characterized in that The inner diameter of the spiral body (110) decreases along the direction from the implant end (111) to the connection end (112).

3. The fistula implant according to claim 2, characterized in that The outer diameter of the spiral body (110) is the same along the length direction between the connecting end (112) and the implantation end (111).

4. The fistula implant according to claim 3, characterized in that An anti-reverse structure (113) is provided on the periphery of the spiral body (110).

5. The fistula implant according to claim 4, characterized in that The anti-return structure (113) is a convex structure, and the convex structure includes one or more of a barb, a barb, an arrow or a fishhook-shaped structure.

6. The fistula implant according to claim 4, characterized in that The anti-return structure (113) is a concave structure, and the concave structure comprises a groove or a groove.

7. The fistula implant according to claim 4, characterized in that The outer surface of the expansion sheet (121) is provided with a convex ridge (122).

8. The fistula implant according to claim 7, characterized in that The fistula implant (100) is made of an absorbable polymer formed by polymerization of lactide monomers and other monomers.

9. The fistula implant according to claim 8, characterized in that The lactide monomers include one or both of lactide and glycolide, and the other monomers include one or more of trimethylene carbonate, caprolactone or p-dioxanone.

10. The fistula implant according to claim 9, characterized in that The mass fraction of the lactide monomers is 50% to 90%, and the mass fraction of the other monomers is 10% to 50%.

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