Anti-displacement variable-diameter support

Abstract

The invention discloses an anti-displacement variable-diameter stent, and relates to the technical field of minimally invasive medical instruments, the stent is formed by sequentially connecting a plurality of standard units end to end, each standard unit is composed of four sections of curves, namely a first curve, a second curve, a second curve, a third curve and a fourth curve, the first curve and the third curve are arranged in parallel, 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, and the first curve and the third curve are C-shaped curves. And the second curve and the fourth curve are in arc shapes with arched central positions and are of central symmetry structures.

Description

Technical Field

[0001] The present invention relates to the technical field of minimally invasive medical devices, and in particular to an anti-displacement variable-diameter stent. Background Art

[0002] Stent implantation refers to a technology that uses puncture, catheterization, balloon catheter expansion and metal stent placement to expand and recanalize narrowed, occluded blood vessels or cavities, thereby solving the blind spots of traditional surgery.

[0003] Vascular and lumen stenosis and occlusion are the treatment strengths of interventional stent implantation technology. It has the advantages of less trauma, high efficacy, low risk, fewer complications, and shorter hospitalization time, and has opened up a new path for vascular and lumen stenosis and occlusion. The development direction of surgery is to exchange the same or even higher efficacy with the smallest possible trauma. The successful clinical application of laparoscopy and coronary artery dilatation and angioplasty is a typical example. The 21st century is the century of minimally invasive medicine. Interventional radiology technology is a major component of minimally invasive medicine, which conforms to the development direction of medicine with minimal trauma, higher efficacy, and lower risk.

[0004] Existing stent implantation, whether intravascular stent or non-intravascular stent, has several common shortcomings:

[0005] 1) Bracket displacement.

[0006] After implantation, the stent is prone to gradual displacement due to the peristalsis of the human tissue cavity or the flow of blood and body fluids, causing the stent to not only be unable to treat the original stenosis and occlusion, but may even cause other side effects such as blockage or damage.

[0007] 2) Tissue ingrowth.

[0008] After the stent is implanted, it is a foreign body to the human body. Not only will the body's own immune system reject it, but the tissue will also gradually cover the stent, causing the tissue to be embedded in the stent cavity, re-forming occlusion or stenosis. After the human tissue is embedded, the stent is covered, and it is very difficult to remove the stent, which will cause great harm to the human body.

[0009] 3) Insufficient compliance with human tissue cavities.

[0010] At present, most stents are woven in a grid-like state, which cannot adapt well to the spatial curvature or torsion of the human tissue cavity, causing the stent to twist and narrow after implantation, or poor wall adhesion, or even failure to implant. Summary of the invention

[0011] Purpose of the invention: The technical problem to be solved by the present invention is to provide an anti-displacement variable-diameter stent, which solves the problems of stent displacement, tissue embedding growth, and insufficient compliance with the human tissue cavity of the existing stent.

[0012] Technical Solution

[0013] To solve the above problems, the technical solution provided by the present invention is:

[0014] A variable diameter anti-displacement bracket, the bracket is composed of a plurality of standard units connected end to end in sequence, each of the standard units is composed of four curves, namely a first curve, a first curve, a second curve, a third curve, and a fourth curve, the first curve and the third curve are arranged in parallel, the second curve is connected to the same end adjacent to the first curve and the third curve, the fourth curve is connected to the third curve and the same end adjacent to 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 shapes arched at the center, and both are centrally symmetrical structures.

[0015] Furthermore, the second curve or the fourth curve and the first curve and the third curve connected on both sides, the three curves form a circularly bent "U"-shaped structure.

[0016] Furthermore, the stent is made of nickel-titanium alloy wire.

[0017] Furthermore, openings or grooves may be provided on the bracket and on the surface of the bracket.

[0018] Furthermore, a coating may be provided on the stent as required, and the coating may be a single-layer or multi-layer structure, and the coating may be provided on the outside, inside or covering the stent.

[0019] Furthermore, the first curve and the third curve are closely attached to each other.

[0020] Furthermore, the second curve and the fourth curve are straight lines parallel to the axial direction of the stent.

[0021] Furthermore, the first curve and the third curve are deflected to any one side of the first curve and the third curve, and the second curve and the fourth curve are arranged correspondingly, and the second curve and the fourth curve are vertically symmetrical with each other.

[0022] Furthermore, the first curve and the third curve in each standard cell are of equal length, the first curve and the third curve between several standard cells are of different lengths, and the second curve and the fourth curve of several standard cells are at different positions.

[0023] Furthermore, the second curves and the fourth curves of a plurality of the standard cells are equidistantly distributed.

[0024] Beneficial Effects

[0025] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0026] 1) The structure of the stent is not a dense spring-like structure, but has gaps and edges. The edges can increase the friction between the stent and the inner wall of the human blood vessel or cavity. The cross section is not closed, but has an open "C" shape, which enables the stent to have the function of radial compression and shrinkage, and can reach the expected position through a narrow space and then expand. The stent is similar to a spring as a whole, with good spatial bending compliance, and can adapt to different bending changes of human blood vessels or cavities.

[0027] 2) The nickel-titanium alloy material of the stent has shape memory. When coated, it can inhibit tissue proliferation and embedding, and has good barrier properties. When not coated, the stent is easier to fix in human tissue and has better anti-displacement performance.

[0028] 3) When the stent is not covered, the holes or grooves on the outside of the stent coil can be loaded with drugs. The drugs have the effects of preventing intimal hyperplasia, tissue embedding, functional treatment, etc.

[0029] 4) The stent is made of specially designed nickel-titanium alloy wire, which can undergo phase change 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 is coated, the coating itself can be single-layer or multi-layer, and can be on the outside, inside or covering the stent to adapt to different usage scenarios;

[0031] 6) The stent coating material can be a common medical coating or a specially designed medical coating with a microporous structure. This so-called special design increases the three-dimensional spatial comparative area of ​​the coating material, and can adsorb drugs on the coating to achieve a sustained release effect. The coating state and whether it has micropores can be combined with the state of drug loading in the outer openings or grooves of the stent itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0033] Figure 2 This is a schematic diagram of a structure deflected in one direction according to Embodiment 2 of the present invention;

[0034] Figure 3 Schematic diagram of the deflection structure in another direction according to Embodiment 2 of the present invention

[0035] Figure 4 This is a schematic diagram of the structure of Example 3 of the present invention. DETAILED DESCRIPTION

[0036] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Example 1

[0038] Combined with Figure 1 A variable-diameter anti-displacement bracket includes a bracket, which is composed of multiple standard units 1 of the same structure. Several standard units 1 are connected end to end to form the bracket. The standard unit 1 here is obtained by decomposing the bracket into the most basic structure for the convenience of explaining the bracket structure. In actual production, the bracket itself is an integrated structure, and is not composed of separate standard units connected in sequence.

[0039] Each standard unit 1 is composed of four curved bending parts, and every two curved parts are connected vertically. The four curved parts are defined as a first curve 11, a second curve 12, a third curve 13, and a fourth curve 14 in sequence, wherein the first curve 11 and the third curve 13 are arranged in parallel, and the second curve 12 and the fourth curve 14 are used to connect and transition the first curve 11 and the third curve 13.

[0040] The first curve 11 and the third curve 13 are both "C" shaped curves, both 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, and the other end of the fourth curve 14 is connected to the end of the first curve 11 in the next section of the standard unit 1 that is not connected to the second curve 12 of the next section of the standard unit 1.

[0041] The second curve 12 connects the same end of the "C"-shaped curve of the first curve 11 and the third curve 13 in the same standard cell 1, and the same end of the "C"-shaped curve of the first curve 11 and the third curve 13 is the adjacent same end of the "C"-shaped curve of the first curve 11 and the third curve 13. The fourth curve 14 is used to connect two adjacent standard cells 1, and the two ends of the fourth curve 14 are respectively connected to the adjacent same end of the third curve 13 of one standard cell 1 and the first curve 11 of another standard cell 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 first curve 11 of the next section of the standard unit 1 , a plurality of standard units form a bracket.

[0043] The second curve 12 or the fourth curve 14 and the first curve 11 and the third curve 13 located on both sides form a circularly curved "U"-shaped structure, and the cross-section of the "U"-shaped 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 circular rings with gaps. The second curve 12 and the fourth curve 14 are arc shapes arched at the center and have a centrally symmetrical structure. The second curve 12 and the fourth curve 14 mainly connect the first curve 11 and the third curve 13.

[0045] In other embodiments, the first curve 11 and the third curve 13 may be closely attached to each other, and the bracket is formed by arranging the first curve 11 and the third curve 13 only once by virtue of their thickness;

[0046] In other embodiments, the second curve 12 and the fourth curve 14 may be straight lines parallel to the axis of the stent, or other irregular lines.

[0047] The stent is made of nickel-titanium alloy wire with a specially designed phase change temperature, which enables the stent to undergo phase change at low temperatures. The overall rigidity and elasticity of the stent are reduced, and the stent can be pulled into a wire shape and removed from the body. It can be coated or not. The nickel-titanium alloy material of the stent has shape memory and can stably maintain its shape at normal temperatures. It will deform at low temperatures and its overall stiffness will be reduced.

[0048] The stent is made of specially designed nickel-titanium alloy wire, which can undergo phase change at low temperatures. The phase change temperature (temperature required for deformation) is generally lower than 15°C, which reduces the overall rigidity and elasticity of the stent. As a result, the stent can be pulled into a wire shape and removed from the body, making it easier for medical staff to remove the stent.

[0049] When making a stent, first prepare a mandrel. The diameter of the mandrel is the inner diameter of the pipe supported by the stent when in use minus the material thickness of the stent. According to the designed size according to the requirements, nickel-titanium wire is wound on the mandrel to form a stent of the desired shape. The stent and the mandrel are then placed in a heat treatment furnace for heat setting. The mandrel is removed and cut to the required length. The stent is surface treated and the ends are polished to complete the preparation of the stent.

[0050] Holes or grooves may be provided on the stent and on the surface of the stent. The holes or grooves on the stent may be used to accommodate drugs. The holes or grooves on the stent are punched on the stent by laser drilling equipment as required, and then the drugs are filled in.

[0051] The surface of the bracket is subjected to etching treatment, and small holes of any shape can be formed on the surface of the bracket through etching treatment. The shape of the small holes can be square, triangle, circle, and other polygons.

[0052] The openings or slots arranged on the outer side of the stent coil are holes, slots or pits in combination of different shapes, numbers and sizes, which are used to place drugs. The drugs can be paclitaxel or rapamycin, etc., or other functional drugs.

[0053] The structure of the stent 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, so that edges are formed when the stent is placed in the pipe. The edges can increase the friction between the stent and the inner wall of the human blood vessel or cavity. The cross section is not closed, but has an open "C" shape, which enables the stent to have the function of radial compression and can reach the expected position through a narrow space and then expand. The stent is similar to a spring as a whole, has good spatial bending compliance, and can adapt to human blood vessels or cavities with different bending changes.

[0054] The stent can be provided with a coating as required, and the coating structure itself can be single-layer or multi-layer, and can be on the outside, inside or covering the stent to adapt to different usage scenarios;

[0055] The stent coating can be, for example, a polyester braided mesh tube, or a thin film such as ePTFE or TPU. The coating can be sutured to the stent, or glued or hot-melt attached to the stent. The coating can be on the outside or inside of the stent alone, or on both the inside and outside of the stent to cover the stent;

[0056] The stent coating material can be a common medical coating or a specially designed medical coating with a microporous structure. This so-called special design increases the three-dimensional spatial comparative area of ​​the coating material, and can adsorb drugs on the coating to achieve a sustained release effect. The coating state and whether it has micropores can be combined with the state of drug loading in the external openings or grooves of the stent itself.

[0057] In the coated state, it can inhibit tissue proliferation and embedding and has good barrier properties.

[0058] Without a coating, the stent is easier to fix in human tissue and has better anti-displacement performance. Without a coating, the holes or grooves on the outside of the stent coil can be loaded with drugs. The drugs have the effects of preventing intimal hyperplasia, tissue embedding, and functional treatment;

[0059] The stent coating material can be a common medical coating or a specially designed medical coating with a microporous structure. If the medical coating is specially designed with a microporous structure, the coating can be loaded with drugs by vacuum adsorption or leaching. The coating structure can be combined with the drug loading structure of the stent opening or groove.

[0060] Example 2

[0061] Combined with Figure 2 and 3 , Example 2 is the deformation structure of Example 1. The anti-displacement variable diameter bracket included in Example 2 is also composed of a number of standard units 1 connected in sequence. Each standard unit 1 is composed of 4 curved curves, namely the first curve 11, the second curve 12, the third curve 13, and the fourth curve 14. The difference from Example 1 is that the first curve 11 and the third curve 13 are deflected, so that the first curve 11 and the third curve 13 are modified from a flat circular ring structure with an opening to a spiral structure offset to one side. That is, the two "peaks" of the second curve 12 and the fourth curve 14 have changed from facing a "valley" formed by the first curve 11 and the third curve 13 to two "peaks" facing each other.

[0062] The positions where the second curve 12 and the fourth curve 14 are connected to the first curve 11 and the third curve 13 remain unchanged. Accordingly, since the first curve 11 and the third curve 13 are offset shapes, the second curve 12 and the fourth curve 14 connect the first curve 11 and the third curve 13 as transition structures. When the second curve 12 and the fourth curve 14 connect the offset first curve 11 and the third curve 13, the second curve 12 and the fourth curve 14 are in the shape of an arc with an arch at the center position. At this time, the central arched positions of the second curve 12 and the fourth curve 14 are arranged to face each other, and the second curve 12 and the fourth curve 14 are in a central vertical symmetrical relationship.

[0063] There is no limitation on the offset direction of the first curve 11 and the third curve 13 . The first curve 11 and the third curve 13 can be offset in any direction of two side directions of the first curve 11 and the third curve 13 , thereby forming different bracket structures.

[0064] Embodiment 2 is two similar deformation structures of embodiment 1. The deformation of embodiment 2 makes it easier for the stent to bend in one direction when subjected to radial force, thereby improving the compliance of the stent with the curved human tissue cavity. At the same time, the two "peaks" of the second curve 12 and the fourth curve 14 become relative designs, which increases the density between each standard unit, improves the overall rigidity of the stent, and increases the radial support force.

[0065] Example 3

[0066] Combined with Figure 4, Example 3 is the deformation structure of Example 1 and Example 2. An anti-displacement variable diameter bracket included in Example 3 is also composed of a plurality of standard units 1 connected in sequence, each standard unit 1 is composed of 4 curved curves, namely a first curve 11, a second curve 12, a third curve 13, and a fourth curve 14, and is different from Example 2 in that: the lengths of the first curve 11 and the third curve 13 in each standard unit 1 are the same, but the lengths of the first curve 11 and the third curve 13 between the plurality of standard units 1 are different, so the positions of the second curve 12 and the fourth curve 14 in the plurality of standard units 1 are different, so that the corresponding positions of the second curve 12 and the fourth curve 14 in the plurality of standard units 1 can be arranged equidistantly or unequally.

[0067] The design feature of the embodiment 3 is that the openings of the "C" shape of the stent (i.e., the two "peaks" of the second curve 12 or the fourth curve 14) are no longer fixed on a straight line in the circumferential direction of the stent, but can be randomly distributed at different positions of the circumference. For example, the "C"-shaped openings are distributed in sequence on the circumference of the stent coil and deflected at an angle to form a spiral spring shape in space, or the "C"-shaped openings are distributed in sequence on both sides of the circumference of the stent coil, or the "C"-shaped openings are distributed in sequence at other positions on the circumference of the stent coil, and so on.

[0068] The "C"-shaped opening of the stent is the "blank" of the coil in the circumferential direction of the stent, and is the lowest point of mechanical rigidity in the circumferential direction. The position change of the "C"-shaped opening of the stent can cause the rigidity of each part of the stent to change. The position of the "C"-shaped opening of the stent can be changed according to actual needs, so as to process and manufacture stents with different rigidity changes to meet the bending, torsion, bending and support requirements of the stent in human tissue.

[0069] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An anti-displacement variable diameter stent, characterized in that: The bracket is composed of a number of standard units connected end to end in sequence, each of the standard units is composed of four curves, namely a first curve, a first curve, a second curve, a third curve, and a fourth curve. The first curve and the third curve are arranged in parallel, the second curve is connected to the same end adjacent to the first curve and the third curve, and the fourth curve is connected to the same end adjacent to the third curve and the first curve of the next standard unit. The first curve and the third curve are "C"-shaped curves, and the second curve and the fourth curve are arc shapes arched at the center, and both are centrally symmetrical structures.

2. The anti-displacement variable diameter stent according to claim 1, characterized in that: The second curve or the fourth curve and the first curve and the third curve connected on both sides, the three curves form a circular curved "U"-shaped structure.

3. The anti-displacement variable diameter stent according to claim 1, characterized in that: The stent is made of nickel-titanium alloy wire.

4. The anti-displacement variable diameter stent according to claim 1, characterized in that: The bracket and the surface of the bracket may be provided with openings or grooves.

5. The anti-displacement variable diameter stent according to claim 1, characterized in that: The stent may be provided with a coating as required, and the coating may be a single-layer or multi-layer structure, and the coating may be provided on the outside, inside or covering the stent.

6. The anti-displacement variable diameter stent according to claim 1, characterized in that: The first curve and the third curve are closely attached to each other.

7. The anti-displacement variable diameter stent according to claim 1, characterized in that: The second curve and the fourth curve are straight lines parallel to the axial direction of the stent.

8. The anti-displacement variable diameter stent according to claim 1, characterized in that: The first curve and the third curve are deflected to any one side of the first curve and the third curve, and the second curve and the fourth curve are arranged correspondingly, and the second curve and the fourth curve are vertically symmetrical with respect to their centers.

9. The anti-displacement variable diameter stent according to claim 1, characterized in that: The first curve and the third curve in each standard cell are of equal length, the first curve and the third curve between several standard cells are of different lengths, and the second curve and the fourth curve of several standard cells are at different positions.

10. The anti-displacement variable diameter stent according to claim 9, characterized in that: The second curves and the fourth curves of a plurality of the standard cells are equidistantly distributed.

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