Anti-displacement variable-diameter support
By designing a variable-diameter scaffold made of nickel-titanium alloy wire to prevent displacement, the problems of scaffold displacement and tissue embedding growth were solved. This achieved good compliance with human tissue cavities and drug sustained release function, and the scaffold can be removed at low temperature.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2026-04-07
AI Technical Summary
Existing stents are prone to displacement after implantation, ingrown growth within tissues, and insufficient compliance with human tissue cavities.
Design a displacement-resistant variable diameter stent made of nickel-titanium alloy wire. The stent consists of several standard units, each of which is composed of four curved segments. It has a "C" shaped structure and a ring-shaped "U" shaped structure. The stent surface can be provided with openings or grooves. The coating can be on the outside, inside or around the stent. The coating material can be drug-loaded. The stent can undergo a phase change at low temperature for easy removal.
The stent has good spatial bending compliance, inhibits tissue proliferation, prevents displacement, can reach the expected position through narrow spaces, the covering can release drugs slowly, and the stent can be pulled out of the body at low temperature.
Smart Images
Figure CN224085514U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of minimally invasive medical device technology, specifically to a variable diameter stent that prevents displacement. Background Technology
[0002] Stent implantation refers to a technique that uses puncture, catheters, balloon catheters to expand and open narrowed or blocked blood vessels or cavities, thus addressing the blind spots of traditional surgery.
[0003] Vascular and luminal stenosis and occlusion are treatment strengths of interventional stent implantation technology. It boasts advantages such as minimal invasiveness, high efficacy, low risk, few complications, and short hospital stays, opening a new path for treating vascular and luminal stenosis and occlusion. Achieving the same or even higher efficacy with minimal trauma is the direction of surgical development, with the successful clinical application of laparoscopy and coronary angioplasty being typical examples. The 21st century is the century of minimally invasive medicine, and interventional radiology technology is a major component of minimally invasive medicine, aligning with the development direction of medicine with minimal trauma, higher efficacy, and lower risk.
[0004] Existing stent implantation techniques, whether endovascular or non-endovascular, share several common shortcomings:
[0005] 1) Stent displacement.
[0006] After implantation, stents are prone to gradually shifting due to the peristalsis of human tissue cavities or the flow of blood and body fluids. This can cause the stent to not only fail to treat the original stenosis and occlusion, but may even cause other side effects such as blockage or damage.
[0007] 2) Embedded growth within tissues.
[0008] After a stent is implanted, it becomes a foreign object in the body. Not only will the body's immune system reject it, but tissue will also gradually encapsulate the stent, causing it to become embedded in the stent's lumen and reform the occlusion or narrowing. Once the stent is embedded in the body's tissue and encapsulated, its removal becomes extremely difficult and can cause significant harm to the body.
[0009] 3) Insufficient compliance with human tissue cavities.
[0010] Currently, most stents are woven in a mesh pattern, which does not conform well to the curvature or twisting of the body's tissue cavities. This can cause the stent to become twisted and narrowed after implantation, or result in poor adhesion to the tissue walls, or even make implantation impossible. Utility Model Content
[0011] Purpose of the utility model: The technical problem to be solved by this utility model is to provide a variable diameter stent that prevents displacement, thereby solving the problems of stent displacement, tissue embedding and growth, and insufficient compliance with human tissue cavities in existing stents.
[0012] Technical solution
[0013] To solve the above problems, the technical solution provided by this utility model is as follows:
[0014] An anti-displacement variable diameter bracket is provided, comprising a number of standard units connected end to end. Each standard unit consists of four curve segments: a first curve, a second curve, a third curve, and a fourth curve. The first and third curves are arranged side by side, the second curve is connected to the same adjacent end of the first and third curves, and the fourth curve is connected to the same adjacent end of the third curve and the first curve of the next standard unit. The first and third curves are C-shaped curves, and the second and fourth curves are arc-shaped curves with an arched center, and both have a centrally symmetrical structure.
[0015] Furthermore, the second curve or the fourth curve, together with the first curve and the third curve located on both sides, form a circular, curved "U"-shaped structure.
[0016] Furthermore, the support is made of nickel-titanium alloy wire.
[0017] Furthermore, openings or slots may be provided on the bracket and on the surface of the bracket.
[0018] Furthermore, the support can be covered with a film as needed, with the film being a single layer or multiple layers, and the film being placed on the outside, inside or covering the support.
[0019] Furthermore, the first curve and the third curve are closely adjacent to each other.
[0020] Furthermore, the second curve and the fourth curve are straight lines parallel to the axis of the support.
[0021] Furthermore, the first curve and the third curve deflect to either side of the first curve and the third curve, and the second curve and the fourth curve are correspondingly arranged, with the second curve and the fourth curve being centrally vertically symmetrical.
[0022] Furthermore, the first curve and the third curve within each standard unit have equal lengths, the first curve and the third curve between several standard units have different lengths, and the second curve and the fourth curve of several standard units are at different positions.
[0023] Furthermore, the second curve and the fourth curve of the plurality of standard units are equidistantly distributed.
[0024] Beneficial effects
[0025] Compared with the prior art, the technical solution provided by this utility model has the following advantages:
[0026] 1) The stent's structure is not a dense, spring-like shape; it has gaps, forming ridges. These ridges increase the friction between the stent and the inner wall of the blood vessel or cavity. The cross-section is not closed but rather a "C" shape with an opening, allowing the stent to compress radially, enabling it to reach the desired location through narrow spaces and then expand. Overall, the stent resembles a spring, exhibiting excellent spatial flexibility, adapting to the varying curvatures of blood vessels or cavities.
[0027] 2) The nickel-titanium alloy material of the scaffold has shape memory properties. When covered, it can inhibit tissue proliferation and embedding, providing good barrier properties. When uncovered, the scaffold is easier to fix within human tissue, offering better anti-displacement performance.
[0028] 3) When the stent is not covered, drugs can be loaded into the holes or grooves on the outside of the stent coil. These drugs have effects such as preventing endometrial hyperplasia, tissue embedding, and functional therapy.
[0029] 4) The stent is made of specially designed nickel-titanium alloy wire that can undergo a phase transition at low temperatures (generally below 15°C), reducing the overall rigidity and elasticity of the stent. This allows the stent to be pulled into a wire shape and removed from the body.
[0030] 5) If the stent has a film, the film itself can be a single layer or multiple layers, and can be on the outside, inside or covering the stent to adapt to different usage scenarios.
[0031] 6) The stent's covering material can be a standard medical covering or a specially designed medical covering with a microporous structure. This so-called special design increases the three-dimensional spatial surface area of the covering material, enabling drug adsorption on the covering and achieving a sustained-release effect. The covering state and whether it has micropores can be combined with the drug-loaded state of the stent itself through external openings or grooves. Attached Figure Description
[0032] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;
[0033] Figure 2 This is a schematic diagram of the deflection structure in one direction according to Embodiment 2 of this utility model;
[0034] Figure 3 This is a schematic diagram of the deflection structure in another direction according to Embodiment 2 of this utility model.
[0035] Figure 4This is a structural schematic diagram of Embodiment 3 of the present invention. Detailed Implementation
[0036] To make the technical solution of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0037] Example 1
[0038] Combined with appendix Figure 1 A variable diameter anti-displacement bracket includes a bracket, which is composed of multiple standard units 1 with the same structure. Several standard units 1 are connected end to end to form the bracket. Here, the standard unit 1 is derived by decomposing the bracket into the most basic structure for the convenience of describing the bracket structure. In actual manufacturing, the bracket itself is an integral structure and is not composed of individual standard units connected in sequence.
[0039] Each standard unit 1 consists of 4 curved bends, with each pair of bends connected vertically. The four bends are defined as the first curve 11, the second curve 12, the third curve 13, and the fourth curve 14, respectively. The first curve 11 and the third curve 13 are set in parallel, while the second curve 12 and the fourth curve 14 are used to connect and transition between the first curve 11 and the third curve 13.
[0040] Both the first curve 11 and the third curve 13 are "C" shaped curves. The two ends of the second curve 12 are respectively connected between the open ends of the "C" shaped curves at the same end of the first curve 11 and the third curve 13. One end of the fourth curve 14 is connected to the end of the "C" shaped curve of the third curve 13 that is not connected to the second curve 12. The other end of the fourth curve 14 is connected to the end of the first curve 11 in the next standard unit 1 that is not connected to the second curve 12 in the next standard unit 1.
[0041] The second curve 12 connects the same end of the "C"-shaped curves of the first curve 11 and the third curve 13 within the same standard unit 1. The same end of the "C"-shaped curves of the first curve 11 and the third curve 13 are adjacent ends of the "C"-shaped curves of the first curve 11 and the third curve 13. The fourth curve 14 is used to connect two adjacent standard units 1. The two ends of the fourth curve 14 are respectively connected to the adjacent ends of the third curve 13 of one standard unit 1 and the first curve 11 of another standard unit 1.
[0042] By connecting the standard units of the first curve 11, the second curve 12, the third curve 13, and the fourth curve 14 with the fourth curve 14 and the first curve 11 of the next standard unit 1, multiple standard units are assembled into a support.
[0043] The second curve 12 or the fourth curve 14, together with the first curve 11 and the third curve 13 located on both sides, form a circular curved "U" structure. The cross-section of the "U" structure is a "C" shape corresponding to the first curve 11 and the third curve 13.
[0044] The first curve 11 and the third curve 13 play a major supporting role. The first curve 11 and the third curve 13 are similar to rings with gaps. The second curve 12 and the fourth curve 14 are arc shapes that are arched at the center and are both centrally symmetrical. The second curve 12 and the fourth curve 14 mainly serve to connect the first curve 11 and the third curve 13.
[0045] In other implementations, the first curve 11 and the third curve 13 can be closely attached to each other, and the support is formed by arranging the first curve 11 and the third curve 13 in one go, relying solely on their thicknesses.
[0046] In other implementations, the second curve 12 and the fourth curve 14 can be straight lines parallel to the support axis, or other irregular lines.
[0047] The stent is made of nickel-titanium alloy wire. The nickel-titanium alloy wire is specially designed with a phase transition temperature, which allows the stent to undergo a phase transition at low temperatures. The overall rigidity and elasticity of the stent decrease, and it can be drawn into a wire and removed from the body. It can be made with or without a membrane. The nickel-titanium alloy material of the stent has shape memory. It can maintain its shape stably at normal temperatures, but it will deform at low temperatures, and the overall rigidity will decrease.
[0048] The stent is made of specially designed nickel-titanium alloy wire that undergoes a phase transition at low temperatures. The phase transition temperature (the temperature required for deformation) is generally below 15°C, which reduces the overall rigidity and elasticity of the stent. This allows the stent to be pulled into a wire shape and removed from the body, making it easier for medical staff to remove the stent.
[0049] When making the bracket, first prepare a mandrel. The diameter of the mandrel is the inner diameter of the pipe supported by the bracket during use minus the thickness of the bracket material. According to the required dimensions, wind nickel-titanium wire on the mandrel to form the bracket of the desired shape. Then place the bracket and mandrel in a heat treatment furnace for heat setting. Remove the mandrel and cut it according to the required length. Perform surface treatment and end grinding on the bracket to complete the preparation of the bracket.
[0050] The stent and its surface may have openings or slots. The openings or slots on the stent can be used to accommodate drugs. The openings or slots on the stent are made on the stent by a laser drilling device according to the requirements, and then the drugs are filled.
[0051] The surface of the bracket is etched, which allows small holes of any shape to be formed on the surface of the bracket. The shape of the small holes can be square, triangular, circular, or other polygonal.
[0052] The openings or slots on the outer side of the stent coil are recesses with holes, slots, or a combination of both, in different shapes, numbers, and sizes, for placing drugs. The drugs can be paclitaxel, rapamycin, or other functional drugs.
[0053] The stent's structure is not a dense, spring-like shape; there are gaps between the first curve 11, the second curve 12, the third curve 13, and the fourth curve 14, creating ridges within the stent's placement within the vessel. These ridges increase the friction between the stent and the inner wall of the blood vessel or cavity. The cross-section is not closed but rather a C-shape with an opening, allowing the stent to compress radially, enabling it to reach the desired location and expand again within confined spaces. Overall, the stent's spring-like shape provides excellent spatial flexibility, adapting to varying curvatures of blood vessels or cavities.
[0054] The support can be covered with a film as needed. The film itself can be a single layer or multiple layers, and can be on the outside, inside or covering the support to adapt to different usage scenarios.
[0055] The scaffold's coating can be, for example, a polyester braided mesh, or a film such as ePTFE or TPU. The coating can be sewn onto the scaffold, or it can be glued or heat-fused onto the scaffold. The coating can be applied solely to the outside or inside of the scaffold, or it can be applied to both the inside and outside of the scaffold, completely covering it.
[0056] The stent's covering material can be a standard medical covering or a specially designed medical covering with a microporous structure. This special design increases the three-dimensional surface area of the covering material, enabling drug adsorption and achieving a sustained-release effect. The covering configuration and the presence or absence of micropores can be combined with the drug-loaded configuration of the stent itself through external openings or grooves.
[0057] When covered with a membrane, it can inhibit tissue proliferation and has good barrier properties.
[0058] Without a liner, the stent is easier to fix within human tissue and has better anti-migration performance. Without a liner, drugs can be loaded into the holes or grooves on the outside of the stent coil. These drugs have effects such as preventing endometrial hyperplasia, tissue embedding, and functional therapy.
[0059] The stent's covering material can be a standard medical covering or a specially designed medical covering with a microporous structure. If the medical covering has a specially designed microporous structure, drug delivery can be achieved through methods such as vacuum adsorption or extraction. The covering structure can be combined with the stent's open or grooved drug delivery structure.
[0060] Example 2
[0061] Combined with appendix Figure 2 and 3 Example 2 is a deformable structure of Example 1. The anti-displacement variable diameter bracket included in Example 2 is also composed of several standard units 1 connected sequentially. Each standard unit 1 consists of four curved bends: a first curve 11, a second curve 12, a third curve 13, and a fourth curve 14. The difference from Example 1 is that the first curve 11 and the third curve 13 are deflected, thus changing their flat, open circular structure into a spiral structure offset to one side. That is, the two "peaks" of the second curve 12 and the fourth curve 14, which were originally facing a "valley" formed by the first curve 11 and the third curve 13 respectively, now face each other.
[0062] The positions of the second curve 12 and the fourth curve 14 on the first curve 11 and the third curve 13 remain unchanged. Correspondingly, since the first curve 11 and the third curve 13 are offset shapes, the second curve 12 and the fourth curve 14 serve as transition structures to connect the first curve 11 and the third curve 13. When the second curve 12 and the fourth curve 14 are connected to the offset first curve 11 and the third curve 13, the second curve 12 and the fourth curve 14 are arc shapes with an arched center position. At this time, the arched center positions of the second curve 12 and the fourth curve 14 are set facing each other, and the second curve 12 and the fourth curve 14 are in a central vertical symmetrical relationship.
[0063] The offset direction of the first curve 11 and the third curve 13 is not restricted. The first curve 11 and the third curve 13 can be offset in any direction to either of the two side directions of the first curve 11 and the third curve 13, thereby forming different support structures.
[0064] Example 2 is a similar deformation structure to Example 1. The deformation in Example 2 makes the stent more flexible in one direction when subjected to radial force, thus improving the stent's compliance with curved human tissue cavities. Simultaneously, the relative design of the two "peaks," the second curve 12 and the fourth curve 14, increases the density between the standard units, thereby improving the overall rigidity of the stent and increasing radial support force.
[0065] Example 3
[0066] Combined with appendix Figure 4Example 3 is a deformation structure of Examples 1 and 2. The anti-displacement variable diameter bracket included in Example 3 is also composed of several standard units 1 connected sequentially. Each standard unit 1 consists of four curved bends: a first curve 11, a second curve 12, a third curve 13, and a fourth curve 14. The difference from Example 2 is that the first curve 11 and the third curve 13 within each standard unit 1 have the same length, but the lengths of the first curve 11 and the third curve 13 differ between several standard units 1. Therefore, the positions of the second curve 12 and the fourth curve 14 within several standard units 1 are different, allowing the corresponding positions of the second curve 12 and the fourth curve 14 within several standard units 1 to be arranged equidistantly or unequally.
[0067] The design feature of Embodiment 3 is that the "C"-shaped openings of the support (i.e., the two "peaks" of the second curve 12 or the fourth curve 14) are no longer fixed on a straight line in sequence along the circumference of the support, but can be randomly distributed at different positions on the circumference. For example, the "C"-shaped openings can be distributed sequentially on the circumference of the support coil at an angle, forming a spatial spiral spring shape, or the "C"-shaped openings can be distributed sequentially on both sides of the circumference of the support coil, or the "C"-shaped openings can be distributed sequentially at other positions on the circumference of the support coil, and so on.
[0068] The "C"-shaped opening of the stent represents a "blank" in the circumferential direction of the coil, marking the lowest point of rigidity in the circumferential direction. Changing the position of this "C"-shaped opening can alter the rigidity of various parts of the stent. By varying the position of the "C"-shaped opening according to specific needs, stents with different rigidity variations can be manufactured to meet the bending, torsion, flexing, and support requirements of human tissue.
[0069] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. A variable diameter anti-displacement bracket, characterized in that, The support structure is composed of several standard units connected end to end. Each standard unit consists of four curve segments: a first curve, a second curve, a third curve, and a fourth curve. The first curve and the third curve are arranged side by side. The second curve is connected to the same adjacent end of the first curve and the third curve. The fourth curve is connected to the same adjacent end of the third curve and the first curve of the next standard unit. The first curve and the third curve are "C"-shaped curves. The second curve and the fourth curve are arc-shaped curves with an arched center position and are both centrally symmetrical.
2. The anti-displacement variable diameter bracket according to claim 1, characterized in that, The second curve or the fourth curve, together with the first curve and the third curve located on both sides, form a circular, curved "U"-shaped structure.
3. The anti-displacement variable diameter bracket according to claim 1, characterized in that, The support is made of nickel-titanium alloy wire.
4. The anti-displacement variable diameter bracket according to claim 1, characterized in that, The bracket and its surface may be provided with openings or slots.
5. The anti-displacement variable diameter bracket according to claim 1, characterized in that, The support can be covered with a film as needed, with the film being a single layer or multiple layers, and the film can be placed on the outside or inside of the support or cover the support.
6. The anti-displacement variable diameter bracket according to claim 1, characterized in that, The first curve and the third curve are closely adjacent to each other.
7. The anti-displacement variable diameter bracket according to claim 1, characterized in that, The second curve and the fourth curve are straight lines parallel to the axis of the support.
8. A variable diameter anti-displacement bracket according to claim 1, characterized in that, The first curve and the third curve deflect to either side of the first curve and the third curve, and the second curve and the fourth curve are set correspondingly, with the second curve and the fourth curve being vertically symmetrical at their centers.
9. A variable diameter anti-displacement bracket according to claim 1, characterized in that, The first curve and the third curve within each standard unit have equal lengths; the first curve and the third curve have different lengths among several standard units; and the second curve and the fourth curve of several standard units are located at different positions.
10. A variable diameter anti-displacement bracket according to claim 9, characterized in that, The second curve and the fourth curve of the plurality of standard units are equidistantly distributed.