CN113813090A

CN113813090A - Support and preparation method thereof

Info

Publication number: CN113813090A
Application number: CN202110924763.5A
Authority: CN
Inventors: 林婧; 王璐; 郭爱军; 王富军; 关国平; 李志荣
Original assignee: USHARE MEDICAL Inc; Donghua University
Current assignee: USHARE MEDICAL Inc; Donghua University
Priority date: 2021-08-12
Filing date: 2021-08-12
Publication date: 2021-12-21
Anticipated expiration: 2041-08-12
Also published as: WO2023016102A1; CN113813090B

Abstract

The invention relates to a bracket and a preparation method thereof, wherein the preparation method comprises the following steps: (1) weaving single or single strands of wire into a cylindrical tubular stent; (2) feeding a single or a plurality of metal wires into a settling arc of a specified penetration position of the cylindrical tubular bracket according to the requirements of the thread pitch, the number, the spiral direction and the penetration period to obtain a semi-finished product; (3) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, performing heat setting, and demolding to obtain a support; the prepared stent comprises a cylindrical tubular stent and a single or a plurality of spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area or one section of the cylindrical tubular support, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular support. The stent has good radial reinforcing effect, good recyclability and good flexibility.

Description

Support and preparation method thereof

Technical Field

The invention belongs to the technical field of stents, and relates to a stent and a preparation method thereof.

Background

Good and malignant stenosis or obstruction of the lumen such as blood vessels, non-blood vessels and the like is a common clinical serious disease, stent implantation is an important palliative treatment means, and an ideal stent needs to have the characteristics of good radial reinforcement effect, good recyclability and good flexibility, but the traditional stent has the following problems:

relying solely on mechanical force for mechanical force restoration by wall deformation does not provide ideal mechanical support, and closure of the stent can easily occur as the stenosis or obstruction continues to progress, resulting in restenosis of the lumen.

At present, the general structural reinforcement method for various pipelines is to add reinforcement parts into the pipe wall, the common reinforcement parts comprise a reinforcement sleeve, an axial reinforcement rib, a radial reinforcement ring and a spiral reinforcement rib, and the reinforcement parts can be used independently or in combination. These reinforcing members are nested or fixed inside or outside the conduit to be reinforced and are commonly subjected to radial compression to enhance radial support, but all of the above methods are only suitable for radial reinforcement of common conduits and do not satisfy the clinical requirements of stent recyclability and flexibility. The spiral reinforcing rib in the common pipeline is poured in the pipe body or embedded in the inner surface and the outer surface of the pipe wall, and the weft knitting support main body cannot be molded by pouring, and the surface of the weft knitting support main body cannot be embedded in a position of a spiral metal wire; moreover, the common pipeline cannot be recycled; in addition, ordinary pipeline spiral strengthening rib and body reciprocal anchorage, when receiving external force, the axial is almost indeformable, can't satisfy the compliance requirement of support.

The existing method for enhancing the radial support of the human body stent tube mainly comprises the following steps: firstly, nesting a plurality of layers of supports; adding an elastic coating; and thirdly, adding reinforcing ribs. The method for nesting the multiple layers of supports is characterized in that the multiple supports are sleeved and implanted into a supporting pipe cavity together, if the multiple recyclable supports are nested without fixed parts, the recyclable performance of the supports can be kept, but the supports prepared by the method are easy to slide mutually in the service process, and the radial reinforcing effect of the supports cannot be guaranteed; the method of adding the elastic coating is not suitable for a recoverable stent, the coating is bonded with the main body of the stent, the recoverable performance of the metal weft-knitted stent is influenced, and the close combination and mechanical matching of the reinforced coating and the stent cannot be ensured by using the reinforcing mode of the coating; the method of adding reinforcing ribs is commonly used for laser engraved stents, which are generally not recyclable, and the addition of reinforcing ribs to weft knitted stents also results in their loss of recyclability.

Therefore, a stent with good radial reinforcement effect, good recyclability and good flexibility is urgently needed to be researched.

Disclosure of Invention

The present invention is directed to solving the above problems of the prior art and to providing a stent and a method for manufacturing the same.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a stent comprising a cylindrical tubular stent and a single or plurality of helical wires;

the cylindrical tubular bracket is formed by processing a single or single-stranded metal wire according to a weft knitting process, and the single-stranded metal wire is formed by twisting more than two metal wires together;

the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket, and the situation of non-coincidence has no practical use value;

the helical wire is threaded in the whole area of the cylindrical tubular stent (the stent in the case can be used for treating benign stenosis of esophagus), the penetrating position and the penetrating position of the helical wire are positioned in the sinker loop of the cylindrical tubular stent, when the stent is recovered, the needle knitted loop and the loop stem of the coil are withdrawn from the coil of the previous row, and the helical wire in the sinker loop does not influence the recovery process, so that the recoverability of the weft knitted stent is reserved;

or, the cylindrical tubular stent is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular stent (in the case of the stent, the stent can be used for assisting in treating esophageal cancer, in the actual use process, the section of the spiral metal wire is positioned at the position of tumor tissue, the esophageal tumor tissue can be effectively prevented from growing to extrude or grow into the stent to cause esophageal restenosis, other sections have no spiral metal wire, other sections are positioned at the position of normal tissue, other sections have no spiral metal wire to be reinforced, complications such as bleeding and necrosis caused by overlarge radial force can be prevented, specifically, the length of the section of the spiral metal wire is determined according to the actual application scene), the penetrating position and the penetrating position of the spiral metal wire are positioned in the subsidence arc of the cylindrical tubular stent, when the stent is recovered, the needle knitting arc and the loop stem of the coil are withdrawn from the coil in the previous transverse row, the spiral metal wires in the settling arc do not influence the recycling process, so that the recyclability of the weft-knitted support is reserved;

the spiral metal wires penetrate and penetrate out of different settlement arcs of the cylindrical tubular bracket independently, or the spiral metal wires are overlapped with each other, and all or part of the spiral metal wires penetrate and penetrate out of the same settlement arc of the cylindrical tubular bracket.

As a preferred technical scheme:

in the stent as described above, since the weft plain stitch, the weft rib stitch, the weft interlock stitch, the weft links-links or the weft tucks are all released in the reverse knitting direction to achieve the stent recyclability, the texture of the cylindrical tubular stent is the weft plain stitch, the weft rib stitch, the weft interlock, the weft links-links or the weft tucks.

Among the weft weaves that are currently relevant to the present invention but differ substantially are: a backing weave, a plaited weave. The cushion stitch forms unclosed suspension arcs on certain loops of the fabric, the other loops stay on the reverse side of the fabric in a floating mode, the cushion yarn must be arranged on the front side and the reverse side of all the loops of the same loop row of the ground stitch, and equivalently, the cushion yarn penetrates through the ground stitch completely, the reinforcing effect of the cushion yarn on the radial support of the support is single, the reinforcing effect can be adjusted by adjusting the thread pitch and the penetrating mode, and the cushion yarn is fed in the same loop row, so that the support is difficult to compress into a sheath in the subsequent radial direction; the plating stitch means that all or part of stitches of the fabric are formed by two yarns, plating can be performed along the direction of the horizontal row of the stitches of the weft knitting support tube to enhance the radial mechanical property, but when the plating stitch is scattered and recovered, the ground yarn and the plating yarn are simultaneously withdrawn from the last horizontal row of stitches, the withdrawal resistance is larger compared with the recovery of the ground stitch, namely, the recovery resistance is larger, in the recovery process, the detached ground yarn and the plating yarn are easy to tangle, the difficulty of the operation under an endoscope is increased, in addition, the rigidity of the metal wire is larger, thicker yarns are not easy to warp and form loops, and the weaving is difficult. The lining and plating stitch belongs to the traditional weft knitting stitch, and is commonly used in the traditional textile fabric, but not used in the weft knitting esophageal stent, and the lining and plating stitch added in the structure are similar to the spiral metal wire in the invention, so that the radial mechanical property of the fabric can be enhanced to a certain extent, but the invention is fundamentally different from the invention.

The cylindrical tubular stent is made of more than one of nickel-titanium alloy, medical stainless steel, cobalt-chromium alloy or magnesium alloy, has good mechanical properties and excellent biocompatibility, and is a commonly used in vivo implantation metal material at present.

In the stent, the length of the cylindrical tubular stent is 50-250 mm, the inner diameter is 10-25 mm, and the diameter of a single or single-strand wire constituting the cylindrical tubular stent (the single-strand wire is formed by twisting two or more wires together, and the diameter of the single-strand wire refers to the diameter of a whole formed by twisting two or more wires together) is 0.035-0.2 mm. If the diameter of the metal wire forming the cylindrical tubular bracket is too low and the strength is insufficient, the metal wire is easy to break during weaving; if the diameter of the metal wire is too large, the bending rigidity is too large, and the yarn can not be smoothly bent and looped during weaving.

The diameter of the spiral metal wire is 0.035-0.3 mm (the thickness of the metal wire is represented), the number of the spiral metal wire is 1-10, the pitch of the spiral metal wire is 5-100 mm, and the spiral direction is positive rotation or negative rotation. If the diameter of the spiral metal wire is too low, the strength is insufficient, and the purpose of enhancing the radial support property of the stent main body (namely the cylindrical tubular stent) cannot be realized; if the diameter of the spiral metal wire is too large, the bending rigidity is too large, and the spiral metal wire cannot smoothly penetrate into the stent main body. If the thread pitch is too large, the radial support enhancing effect on the support is not good; if the thread pitch is too small, the floating line of the threaded metal wire is too long, and the stent can be dragged by coarse food after being placed, and the flexibility of the stent can be influenced. When the helical wire is a plurality of wires, it is preferable that each of the helical wires has the same diameter.

In the stent, the number of the spiral wires is d, d is an even number, wherein the spiral directions of d/2 spiral wires are all positive rotations, the spiral directions of d/2 spiral wires are all negative rotations, and preferably, the spiral wires with opposite spiral directions are symmetrically distributed. Under the condition, the support is not easy to twist, and the reinforcing effect is better.

In the stent, the material of the spiral metal wire is more than one of nickel-titanium alloy, medical stainless steel, cobalt-chromium alloy or magnesium alloy.

A stent as described above, the helical wire press

And periodically sleeving the circular knitting machine in the whole area or a section of the cylindrical tubular support, wherein n is the number of the vertical lines of the coils between the penetrating positions and the penetrating positions of the spiral metal wires, m is the number of the horizontal lines of the coils between the penetrating positions and the penetrating positions of the spiral metal wires, and n is smaller than the total number of the vertical lines of the cylindrical tubular support (namely the number of needle cylinders of the circular knitting machine used in preparation).

According to the stent, the radial force of the section where the spiral metal wire is located in the stent is 1.4-6.6 times that of the cylindrical tubular stent, the radial compression performance is measured by using an RX550 force measuring device, the compression force when the diameter is compressed to 50% of the initial diameter is taken as the radial force, the radial force of the cylindrical tubular stent is 15-40N, and the radial force of the stent is 15-320N.

The invention also provides a method of preparing a scaffold as described in any one of the above, comprising the steps of:

(1) weaving a single or single-stranded metal wire into a cylindrical tubular support by using a circular knitting machine with a small needle cylinder diameter, wherein the metal wire has high rigidity, the yarn bending and looping have certain difficulty, and in order to ensure the weaving smoothness, the needle cylinder diameter of the circular knitting machine is 15-35 mm, and the needle number is 12-50 needles;

(2) feeding a single or a plurality of metal wires into a settling arc of a specified penetration position of the cylindrical tubular support according to the requirements of thread pitch, number, spiral direction and penetration period, so that the spiral metal wires are penetrated and sleeved in the whole area or one section of the cylindrical tubular support to obtain a semi-finished product;

(3) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, then performing heat setting at a certain temperature, and demolding to obtain a bracket;

when the material of the metal wire in the step (1) is different from that of the metal wire in the step (2) and the heat setting temperature of the metal wire in the step (1) is higher, fixing the two ends of the cylindrical tubular support after the step (1) is finished, and then performing heat setting;

when the material of the metal wire in the step (1) is different from that of the metal wire in the step (2) and the heat setting temperature of the metal wire in the step (1) is lower, before the metal wire in the step (2) is fed into a settling arc, the metal wire is spirally wound on a screw rod according to the requirements of the thread pitch and the spiral direction, and the metal wire is heat-set after the two ends are fixed;

the material of the metal wire and the corresponding relation of the heat setting temperature are as follows: nickel-titanium alloy, 500-650 ℃; 450-550 ℃ of medical stainless steel; cobalt-chromium alloy, 800-1150 ℃; magnesium alloy, 100-200 ℃;

the heat setting time is 5-30 min each time;

the heat setting can eliminate the internal stress, so that the structure of the stent is stable, an oxide layer can be formed on the surface of the material, the release of metal ions in the body is avoided, and when the metal wire is made of nickel-titanium alloy, the heat setting can also reduce the martensite phase transition temperature of the metal wire to be below the body temperature, so that the self-expansion after the metal wire is placed in the stent is realized.

When the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket, the cylindrical tubular bracket is preferably processed by a single metal wire according to a weft knitting process, the spiral metal wire is single, the metal wire forming the cylindrical tubular bracket and the spiral metal wire are two sections on the same metal wire, the whole bracket is made of one metal wire at the moment, the tail end of the cylindrical tubular bracket is connected with the spiral metal wire, the head end of the clamped cylindrical tubular bracket is used for pulling and disassembling the cylindrical tubular bracket, and then the spiral wire is pulled and recovered, and the preparation steps of the bracket are as follows:

(1) after reserving a certain length section for a single metal wire, weaving the single metal wire into a cylindrical tubular support by using a circular knitting machine with a small needle cylinder diameter, wherein the metal wire has higher rigidity, certain difficulty is caused by yarn bending and looping, and in order to ensure smooth weaving, the needle cylinder diameter of the circular knitting machine is 15-35 mm, and the needle number is 12-50 needles;

(2) spirally feeding the reserved section of the single metal wire in the step (1) into a settling arc at a specified penetration position of the cylindrical tubular support according to the pitch, the spiral direction and the penetration period, so that the spiral metal wire is penetrated and sleeved in the whole area of the cylindrical tubular support to obtain a semi-finished product;

the heat setting time is 5-30 min each time.

The principle of the invention is as follows:

the bracket with high radial support performance consists of a cylindrical tubular bracket made of single or single-stranded metal wires based on a weft knitting process and single or multiple spiral metal wires, wherein the single or multiple spiral metal wires are formed by orderly sleeving in a sinking arc of the cylindrical tubular bracket. By feeding spiral metal wires with different diameters, pitches and numbers, the radial support property of the stent is effectively improved on the basis of ensuring the clinical requirements of the flexibility and the in-vivo recoverability of the stent, and the smoothness of cavities such as blood vessels, non-blood vessels and the like is ensured.

Due to the addition of the spiral metal wire, when the cylindrical tubular bracket is compressed in the radial direction, the spiral metal wire and the cylindrical tubular bracket are stressed together, so that the aim of radial reinforcement is fulfilled; and the penetration and penetration positions of the spiral metal wire are arranged in the subsidence arc of the cylindrical tubular support, when the support is recovered, the needle knitting arc and the loop stem of the coil are withdrawn from the coil of the last transverse row, and the spiral metal wire in the subsidence arc does not influence the recovery process, so that the recoverability of the weft knitting support is kept (after the cylindrical tubular support is recovered, the head end of the clamped spiral metal wire can be pulled and taken out). In addition, the spiral metal wire has certain axial deformability, is positioned in a settling arc of the stent main body (namely the cylindrical tubular stent), has a certain moving range relative to the stent main body, and can move in a small range in the settling arc when being subjected to external force, so that the spiral metal wire has larger deformability and has smaller influence on the flexibility of the stent main body.

Has the advantages that:

(1) the preparation method of the stent effectively improves the radial support property of the stent and ensures the smoothness of the lumen such as blood vessels, non-blood vessels and the like on the premise of ensuring the clinical requirements of the flexibility and the in vivo recoverability of the stent;

(2) the invention finally prepares a bracket, the bracket still keeps the recyclability of the weft knitting bracket, and the radial force of the section of the spiral metal wire is 1.4-6.6 times of that of the cylindrical tubular bracket so as to match different mechanical requirements.

Drawings

FIG. 1 is a schematic structural view of a stent prepared in example 1;

FIG. 2 shows the wire arrangement of example 1 when preparing a stent

A schematic diagram of a periodic feeding mode;

FIG. 3 shows the wire arrangement of example 2 when preparing a stent

A schematic diagram of a periodic feeding mode;

FIG. 4 is a schematic view showing a recycling process of the stent obtained in example 1;

FIG. 5 is a schematic structural view of a stent obtained in example 9;

FIG. 6 is a schematic structural view of a stent obtained in example 15;

FIG. 7 is a schematic view showing a recovery process of the stent obtained in example 15;

FIG. 8 is a schematic structural view of a stent produced in example 22;

wherein, 1-cylindrical tubular stent, 2-spiral metal wire, 3-penetrating position, 4-penetrating position, and 5-metal wire head end.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

Example 1

A preparation method of a stent comprises the following specific steps:

(1) weaving a single metal wire (the diameter is 0.12mm) made of nickel-titanium alloy into a cylindrical tubular bracket by using a circular weft knitting machine (the diameter of a needle cylinder is 25mm, the needle number is 22 needles) with a small needle cylinder diameter according to a weft knitting process, wherein the organization structure of the cylindrical tubular bracket is a weft-knitted plain stitch, the length of the cylindrical tubular bracket is 120mm, and the inner diameter of the cylindrical tubular bracket is 20 mm;

(2) as shown in fig. 1 and 2, 4 metal wires (with the same diameter and 0.20mm) made of nitinol are threaded according to a thread pitch (60mm), a number (4) of the metal wires, a spiral direction (all counter-rotating) and a threading period (i)

Period, n is the number of the coil rows between the penetrating position 3 and the penetrating position 4 of the spiral metal wire 2, and m is the number of the coil rows between the penetrating position 3 and the penetrating position 4 of the spiral metal wire 2N and m are both 1), and spirally feeding the spiral metal wire into a settling arc at a specified penetration position of the cylindrical tubular support 1 to enable the spiral metal wire to penetrate and sleeve in the whole area of the cylindrical tubular support to obtain a semi-finished product;

(3) and (4) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, then carrying out heat setting at 550 ℃ for 15min, and demoulding to obtain the bracket.

As shown in fig. 1, a stent is finally obtained, which comprises a cylindrical tubular stent 1 and 4 helical wires 2; the central axis of the spiral metal wire 2 is superposed with the central axis of the cylindrical tubular bracket 1; the spiral metal wire 2 is sleeved in the whole area of the cylindrical tubular bracket 1 in a penetrating way, and the penetrating position of the spiral metal wire 2 are positioned in a sinking arc of the cylindrical tubular bracket 1; the 4 spiral metal wires 2 are parallel to each other, and the axial distance between two adjacent spiral metal wires (namely, the distance between two adjacent spiral metal wires in the same coil column of the cylindrical tubular stent along the axial direction of the cylindrical tubular stent) is 15 mm; the radial force of the stent is 2.9 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 28N, and the radial force of the stent is 80N); as shown in fig. 4, which is a schematic view of the recycling process of the stent manufactured in example 1, the metal filament end 5 is pulled, the stent is loosened, the spiral metal wire 2 is separated, and the cylindrical tubular stent 1 is disassembled into one yarn to be recycled.

Example 2

A preparation method of a stent comprises the following specific steps:

(1) weaving a single metal wire (the diameter is 0.12mm) made of nickel-titanium alloy into a cylindrical tubular bracket by using a circular weft knitting machine (the diameter of a needle cylinder is 20mm, the needle number is 15 needles) with a small needle cylinder diameter according to a weft knitting process, wherein the organization structure of the cylindrical tubular bracket is a weft-knitted plain stitch, the length of the cylindrical tubular bracket is 150mm, and the inner diameter of the cylindrical tubular bracket is 18 mm;

(2) as shown in figure 3, 2 metal wires (with the same diameter and 0.15mm) made of nickel-titanium alloy are arranged according to the pitch (70mm), the number (2) of the metal wires, the spiral direction (all are in reverse rotation) and the sleeving period (the period of the metal wires is (1)

The period is that n is the number of the coil columns between the penetrating position 3 and the penetrating position 4 of the spiral metal wire 2, m is the number of the coil columns between the penetrating position 3 and the penetrating position 4 of the spiral metal wire 2, n is 2, and m is 1), and the spiral metal wire is required to be fed into a settling arc of the specified penetrating and penetrating position of the cylindrical tubular support 1, so that the spiral metal wire is penetrated and sleeved in the whole area of the cylindrical tubular support to obtain a semi-finished product;

(3) and (3) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, then carrying out heat setting at 600 ℃ for 10min, and demoulding to obtain the bracket.

The finally prepared stent comprises a cylindrical tubular stent and 2 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; 2 spiral metal wires are parallel to each other, and the axial distance between two adjacent spiral metal wires (namely, the distance between two spiral metal wires in the same coil column of the cylindrical tubular stent along the axial direction of the cylindrical tubular stent) is 35 mm; the radial force of the stent is 2.8 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 20N, and the radial force of the stent is 56N).

Example 3

A preparation method of a stent comprises the following specific steps:

(1) according to the weft knitting process, a round weft knitting machine (the diameter of a needle cylinder is 20mm, the number of needles is 25) with a small needle cylinder diameter is used for weaving single-stranded metal wires (the diameter is 0.14mm) made of medical stainless steel into a cylindrical tubular support, the organization structure of the cylindrical tubular support is weft knitting rib weave, the length of the cylindrical tubular support is 100mm, and the inner diameter of the cylindrical tubular support is 18 mm; the single-strand metal wire is formed by twisting 2 metal wires together;

(2) using a single metal wire (diameter is 0.30mm) made of medical stainless steel as a threading sleeve according to the pitch (50mm), the number (1), the spiral direction (positive rotation)Period (A)

Period, n is the number of the coil columns between the penetrating positions of the spiral metal wires, m is the number of the coil columns between the penetrating positions of the spiral metal wires, and both n and m are 2) to require the spiral feeding into a settling arc of the specified penetrating positions of the cylindrical tubular support, so that the spiral metal wires are penetrated and sleeved in the whole area of the cylindrical tubular support to obtain a semi-finished product;

(3) and (4) sleeving the semi-finished product on the core rod, fixing two ends of the core rod, then carrying out heat setting at 450 ℃ for 25min, and demoulding to obtain the bracket.

The prepared stent comprises a cylindrical tubular stent and a single spiral metal wire; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the radial force of the stent is 1.5 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is 38N when the diameter is compressed to 50% of the initial diameter, and is 58N).

Example 4

A preparation method of a stent comprises the following specific steps:

(1) weaving single-stranded metal wires (the diameter is 0.10mm) made of cobalt-chromium alloy into a cylindrical tubular bracket by using a circular weft knitting machine (the diameter of a needle cylinder is 30mm, the number of needles is 12) with a small needle cylinder diameter according to a weft knitting process, wherein the tissue structure of the cylindrical tubular bracket is weft-knitted links-links, the length of the cylindrical tubular bracket is 120mm, and the inner diameter of the cylindrical tubular bracket is 23 mm; the single-strand metal wire is formed by twisting 3 metal wires together;

(2) 3 metal wires (with the same diameter and 0.08mm) made of cobalt-chromium alloy are arranged according to the pitch (60mm), the number (3), the spiral direction (all positive rotation) and the sleeving period (

(3) and (4) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, then carrying out heat setting at 950 ℃ for 15min, and demoulding to obtain the bracket.

The finally prepared stent comprises a cylindrical tubular stent and 3 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the 3 spiral metal wires independently penetrate into and out of different sedimentation arcs of the cylindrical tubular support, the 3 spiral metal wires are parallel to each other, and the axial distance between every two adjacent spiral metal wires (namely, the distance between every two adjacent spiral metal wires in the same coil column of the cylindrical tubular support along the axial direction of the cylindrical tubular support) is 20 mm; the radial force of the stent is 3 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is 21N and 64N when the diameter is compressed to 50% of the initial diameter.

Example 5

A preparation method of a stent comprises the following specific steps:

(1) according to the weft knitting process, weaving a single metal wire (the diameter is 0.18mm) made of magnesium alloy into a cylindrical tubular bracket by using a circular weft knitting machine (the diameter of a needle cylinder is 15mm, and the number of needles is 15) with a small needle cylinder diameter, wherein the organization structure of the cylindrical tubular bracket is a weft knitting tuck stitch, the length of the cylindrical tubular bracket is 160mm, and the inner diameter of the cylindrical tubular bracket is 10 mm;

(2) 3 metal wires (with the same diameter and 0.25mm) made of magnesium alloy are arranged according to the pitch (45mm), the number (3), the spiral direction (all positive rotation) and the sleeving period (

(3) and (4) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, then carrying out heat setting at 150 ℃ for 20min, and demoulding to obtain the bracket.

The finally prepared stent comprises a cylindrical tubular stent and 3 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the 3 spiral metal wires independently penetrate into and out of different sedimentation arcs of the cylindrical tubular support, the 3 spiral metal wires are parallel to each other, and the axial distance between every two adjacent spiral metal wires (namely, the distance between every two adjacent spiral metal wires in the same coil column of the cylindrical tubular support along the axial direction of the cylindrical tubular support) is 15 mm; the radial force of the stent is 3.4 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is 32N when the diameter is compressed to 50% of the initial diameter, and the radial force of the cylindrical tubular stent is 108N).

Example 6

A preparation method of a stent is basically the same as that of the embodiment 1, except that the metal wire in the step (2) is cobalt-chromium alloy, before the metal wire in the step (2) is fed into a settling arc, the metal wire is spirally wound on a screw rod according to the requirements of the thread pitch and the spiral direction, and after the two ends are fixed, the metal wire is subjected to heat setting at 800 ℃ for 20 min.

The finally prepared stent comprises a cylindrical tubular stent and 4 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the radial force of the stent is 3.1 times that of the cylindrical tubular stent prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 28N, and the radial force of the stent is 86N).

Example 7

A preparation method of a stent is basically the same as that of the embodiment 1, except that the metal wire in the step (1) is cobalt-chromium alloy, and after the step (1) is finished, two ends of a cylindrical tubular stent are fixed and then are subjected to heat setting at 1150 ℃ for 5 min.

The finally prepared stent comprises a cylindrical tubular stent and 4 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the radial force of the stent is 2.6 times that of the cylindrical tubular stent prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 36N, and the radial force of the stent is 92N).

Example 8

A preparation method of a stent is basically the same as that of the embodiment 1, and is only different in that the metal wire in the step (2) is a single metal wire, the material and the diameter of the metal wire are the same as those of the metal wire in the step (1), and the metal wire in the step (2) is a reserved section of the metal wire in the step (1).

The finally manufactured bracket is integrally made of a metal wire, the recovery is very convenient, the head end of the cylindrical tubular bracket is clamped to pull the detachable cylindrical tubular bracket, and then the spiral wire is pulled and recovered.

Example 9

A stent preparation method, which is basically the same as example 1, except that the number of the metal wires in the step (2) is 8, wherein the spiral directions of 4 spiral metal wires are all positive-spinning, and the spiral directions of 4 spiral metal wires are all reverse-spinning.

As shown in fig. 5, a stent was finally obtained, which comprised a cylindrical tubular stent and 8 helical wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; 4 spiral metal wires with the same spiral direction are parallel to each other, and the axial distance between every two adjacent spiral metal wires (namely, the distance between every two adjacent spiral metal wires in the same coil column of the cylindrical tubular stent along the axial direction of the cylindrical tubular stent) is 15 mm; the spiral metal wires with opposite spiral directions are symmetrically distributed; the radial force of the stent is 6.6 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is measured as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 28N, and the radial force of the stent is 187N).

Example 10

A method for preparing a stent, which is substantially the same as that of example 1, except that in step (2), the spiral directions of 4 metal wires are not completely the same, wherein the spiral directions of 2 spiral metal wires are all positive-rotation, and the spiral directions of 2 spiral metal wires are all negative-rotation.

The finally prepared stent comprises a cylindrical tubular stent and 4 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; 2 spiral metal wires with the same spiral direction are parallel to each other, and the axial distance between every two adjacent spiral metal wires (namely, the distance between every two adjacent spiral metal wires in the same coil column of the cylindrical tubular support along the axial direction of the cylindrical tubular support) is 15 mm; the spiral metal wires with opposite spiral directions are symmetrically distributed; the radial force of the stent is 3.3 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 28N, and the radial force of the stent is 92N).

Example 11

A preparation method of a stent comprises the following specific steps:

(1) after reserving a certain length section of a single metal wire (the diameter is 0.12mm) made of nickel-titanium alloy, weaving the metal wire into a cylindrical tubular bracket by using a circular weft knitting machine (the diameter of a needle cylinder is 15mm, the number of needles is 12) with a small needle cylinder diameter according to a weft knitting process, wherein the organization structure of the cylindrical tubular bracket is a weft-knitted plain stitch structure, the length of the cylindrical tubular bracket is 120mm, and the inner diameter of the cylindrical tubular bracket is 20 mm;

(2) the reserved section of the single metal wire in the step (1) is arranged according to the pitch (60mm), the spiral direction (reverse rotation) and the threading period (

The period is that n is the number of the coil columns between the penetrating position and the penetrating position of the spiral metal wire, m is the number of the coil columns between the penetrating position and the penetrating position of the spiral metal wire, and both n and m are 1), the spiral metal wire is required to be fed into a settling arc of the specified penetrating and penetrating position of the cylindrical tubular support, so that the spiral metal wire is penetrated and sleeved in the whole area of the cylindrical tubular support, and a semi-finished product is obtained;

The finally prepared stent comprises a cylindrical tubular stent and a single spiral metal wire; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the radial force of the support is 1.6 times of that of the cylindrical tubular support 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, the compression force when the diameter is compressed to 50% of the initial diameter is taken as the radial force, the radial force of the cylindrical tubular support is 18N, the radial force of the support is 29N), the support is very convenient to recover, the head end of the cylindrical tubular support is clamped to pull and disassemble the cylindrical tubular support, and then the spiral wire is pulled and recovered.

Example 12

A preparation method of a stent comprises the following specific steps:

(1) after a certain length section is reserved for a single metal wire (the diameter is 0.14mm) made of medical stainless steel, according to a weft knitting process, a circular weft knitting machine (the diameter of a needle cylinder is 35mm, the number of needles is 50 needles) with a small needle cylinder diameter is used for knitting the metal wire into a cylindrical tubular support, the organization structure of the cylindrical tubular support is weft-knitted plain stitch, the length of the cylindrical tubular support is 120mm, and the inner diameter of the cylindrical tubular support is 20 mm;

(2) the reserved section of the single metal wire in the step (1) is arranged according to the thread pitch (70mm), the spiral direction (reverse rotation) and the threading period (

(3) and (4) sleeving the semi-finished product on the core rod, fixing two ends of the core rod, then carrying out heat setting at 450 ℃ for 15min, and demoulding to obtain the bracket.

The finally prepared stent comprises a cylindrical tubular stent and a single spiral metal wire; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the radial force of the support is 2.2 times of that of the cylindrical tubular support 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, the compression force when the diameter is compressed to 50% of the initial diameter is taken as the radial force, the radial force of the cylindrical tubular support is 34N, and the radial force of the support is 72N), the support is very convenient to recover, the head end of the cylindrical tubular support is clamped to pull and disassemble the cylindrical tubular support, and then the spiral wire is pulled and recovered.

Example 13

A preparation method of a stent comprises the following specific steps:

(1) after reserving a certain length section of a single metal wire (the diameter is 0.16mm) made of cobalt-chromium alloy, weaving the metal wire into a cylindrical tubular bracket by using a circular weft knitting machine (the diameter of a needle cylinder is 20mm, the number of needles is 20 needles) with a small needle cylinder diameter according to a weft knitting process, wherein the organization structure of the cylindrical tubular bracket is a weft-knitted plain stitch organization, the length of the cylindrical tubular bracket is 120mm, and the inner diameter of the cylindrical tubular bracket is 20 mm;

(2) the reserved section of the single metal wire in the step (1) is arranged according to the thread pitch (80mm), the spiral direction (reverse rotation) and the threading period (

(3) and (4) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, then carrying out heat setting at 800 ℃ for 15min, and demoulding to obtain the bracket.

The finally prepared stent comprises a cylindrical tubular stent and a single spiral metal wire; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the radial force of the support is 1.9 times of that of the cylindrical tubular support 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, the compression force when the diameter is compressed to 50% of the initial diameter is taken as the radial force, the radial force of the cylindrical tubular support is 29N, and the radial force of the support is 55N), the support is very convenient to recover, the head end of the cylindrical tubular support is clamped to pull and disassemble the cylindrical tubular support, and then the spiral wire is pulled and recovered.

Example 14

A preparation method of a stent comprises the following specific steps:

(1) after a certain length section is reserved for a single metal wire (the diameter is 0.18mm) made of magnesium alloy, according to a weft knitting process, a circular weft knitting machine (the diameter of a needle cylinder is 25mm, the number of needles is 35 needles) with a small needle cylinder diameter is used for knitting the metal wire into a cylindrical tubular support, the organization structure of the cylindrical tubular support is a weft-knitted flat needle organization, the length of the cylindrical tubular support is 120mm, and the inner diameter of the cylindrical tubular support is 20 mm;

(2) the reserved section of the single metal wire in the step (1) is arranged according to the pitch (50mm), the spiral direction (reverse rotation) and the threading period (

(3) and (4) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, then carrying out heat setting at 100 ℃ for 15min, and demoulding to obtain the bracket.

The finally prepared stent comprises a cylindrical tubular stent and a single spiral metal wire; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; the radial force of the support is 2.3 times of that of the cylindrical tubular support 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, the compression force when the diameter is compressed to 50% of the initial diameter is taken as the radial force, the radial force of the cylindrical tubular support is 34N, and the radial force of the support is 77N), the support is very convenient to recover, the head end of the cylindrical tubular support is clamped to pull and disassemble the cylindrical tubular support, and then the spiral wire is pulled and recovered.

Example 15

A preparation method of a stent comprises the following specific steps:

(2) 1 wire (diameter is 0.20mm) made of nickel-titanium alloy is arranged according to the pitch (60mm), the number (1), the spiral direction (all are reverse rotation) and the sleeving period (

The period is that n is the number of the coil columns between the penetrating position and the penetrating position of the spiral metal wire, m is the number of the coil columns between the penetrating position and the penetrating position of the spiral metal wire, and both n and m are 1), the spiral metal wire is required to be fed into a settling arc of the specified penetrating and penetrating position of the cylindrical tubular support, so that the spiral metal wire is penetrated and sleeved in one section of the cylindrical tubular support, and a semi-finished product is obtained;

As shown in fig. 6, a stent is finally obtained, which comprises a cylindrical tubular stent 1 and 1 helical wire 2; the central axis of the spiral metal wire 2 is superposed with the central axis of the cylindrical tubular bracket 1; the cylindrical tubular support 1 is divided into a plurality of sections along the length direction, the spiral metal wire 2 is only sleeved in one section of the cylindrical tubular support 1 in a penetrating mode, and the penetrating position of the spiral metal wire 2 are located in a settling arc of the cylindrical tubular support 1; the radial force of the section of the stent in which the spiral metal wire is positioned is 1.4 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 28N, and the radial force of the section of the stent in which the spiral metal wire is positioned is 38N); as shown in fig. 7, which is a schematic view of the recycling process of the stent manufactured in example 15, the metal filament end 5 is pulled, the stent is loosened, the spiral metal wire 2 is separated, and the cylindrical tubular stent 1 is disassembled into one yarn to be recycled.

Example 16

A preparation method of a stent comprises the following specific steps:

(2) 2 metal wires (with the same diameter and 0.15mm) made of nickel-titanium alloy are arranged according to the pitch (70mm), the number (2), the spiral direction (all are reverse-rotation) and the sleeving period (

The period is that n is the number of the coil columns between the penetrating position and the penetrating position of the spiral metal wire, m is the number of the coil columns between the penetrating position and the penetrating position of the spiral metal wire, n is 2, and m is 1), the spiral metal wire is required to be fed into a settling arc of the specified penetrating and penetrating position of the cylindrical tubular support in a spiral mode, so that the spiral metal wire is sleeved in one section of the cylindrical tubular support in a penetrating mode, and a semi-finished product is obtained;

The finally prepared stent comprises a cylindrical tubular stent and 2 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular support in a penetrating mode, and the penetrating position of the spiral metal wire are located in a settling arc of the cylindrical tubular support; 2 spiral metal wires are parallel to each other, and the axial distance between two adjacent spiral metal wires (namely, the distance between two spiral metal wires in the same coil column of the cylindrical tubular stent along the axial direction of the cylindrical tubular stent) is 35 mm; the radial force of the section where the spiral wire is located in the stent is 2.8 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 20N, and the radial force of the section where the spiral wire is located in the stent is 56N).

Example 17

A preparation method of a stent comprises the following specific steps:

(2) a single metal wire (the diameter is 0.30mm) made of medical stainless steel is arranged according to the pitch (50mm), the number (1), the spiral direction (positive rotation) and the sleeving period (the period of penetration)

Period, n is the number of the coil columns between the penetrating positions of the spiral metal wires, m is the number of the coil columns between the penetrating positions of the spiral metal wires, and both n and m are 2) the spiral metal wires are required to be fed into a settling arc of the specified penetrating positions of the cylindrical tubular support, so that the spiral metal wires are penetrated and sleeved in one section of the cylindrical tubular support to obtain a semi-finished product;

The prepared stent comprises a cylindrical tubular stent and a single spiral metal wire; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular support in a penetrating mode, and the penetrating position of the spiral metal wire are located in a settling arc of the cylindrical tubular support; the radial force of the section where the spiral wire is located in the stent is 1.5 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is measured by taking the compression force when the diameter is compressed to 50% of the initial diameter as the radial force, the radial force of the cylindrical tubular stent is 38N, and the radial force of the section where the spiral wire is located in the stent is 58N).

Example 18

A preparation method of a stent comprises the following specific steps:

The finally prepared stent comprises a cylindrical tubular stent and 3 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular support in a penetrating mode, and the penetrating position of the spiral metal wire are located in a settling arc of the cylindrical tubular support; the 3 spiral metal wires independently penetrate into and out of different sedimentation arcs of the cylindrical tubular support, the 3 spiral metal wires are parallel to each other, and the axial distance between every two adjacent spiral metal wires (namely, the distance between every two adjacent spiral metal wires in the same coil column of the cylindrical tubular support along the axial direction of the cylindrical tubular support) is 20 mm; the radial force of the section where the spiral wire is located in the stent is 3 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 force measuring device, and the radial force is 21N when the diameter is compressed to 50% of the initial diameter, and the radial force of the section where the spiral wire is located in the stent is 64N).

Example 19

A preparation method of a stent comprises the following specific steps:

The finally prepared stent comprises a cylindrical tubular stent and 3 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular support in a penetrating mode, and the penetrating position of the spiral metal wire are located in a settling arc of the cylindrical tubular support; the 3 spiral metal wires independently penetrate into and out of different sedimentation arcs of the cylindrical tubular support, the 3 spiral metal wires are parallel to each other, and the axial distance between every two adjacent spiral metal wires (namely, the distance between every two adjacent spiral metal wires in the same coil column of the cylindrical tubular support along the axial direction of the cylindrical tubular support) is 15 mm; the radial force of the section where the spiral wire is located in the stent is 3.4 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 force measuring device, and the radial force is 32N when the diameter is compressed to 50% of the initial diameter, and the radial force of the section where the spiral wire is located in the stent is 108N).

Example 20

A method for preparing a stent, which is substantially the same as example 15, except that the wire of step (2) is cobalt-chromium alloy, and the wire of step (2) is spirally wound on a screw according to the requirements of the pitch and the spiral direction before being fed into a settling arc, and both ends are fixed and then heat-set at 800 ℃ for 20 min.

The finally prepared stent comprises a cylindrical tubular stent and 4 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular support in a penetrating mode, and the penetrating position of the spiral metal wire are located in a settling arc of the cylindrical tubular support; the radial force of the section of the stent where the spiral wires are located is 1.5 times that of the cylindrical tubular stent prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 28N, and the radial force of the section of the stent where the spiral wires are located is 42N).

Example 21

A stent preparation method, which is basically the same as the embodiment 15, except that the metal wire in the step (1) is cobalt-chromium alloy, after the step (1) is finished, the two ends of the cylindrical tubular stent are fixed, and then are heat-set for 5min at 1150 ℃.

The finally prepared stent comprises a cylindrical tubular stent and 4 spiral metal wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular support in a penetrating mode, and the penetrating position of the spiral metal wire are located in a settling arc of the cylindrical tubular support; the radial force of the section of the stent where the spiral wires are located is 1.5 times that of the cylindrical tubular stent prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 36N, and the radial force of the section of the stent where the spiral wires are located is 55N).

Example 22

A method for preparing a stent, which is substantially the same as in example 15, except that the number of the metal wires in the step (2) is 2, wherein the spiral directions of 1 spiral metal wire are all positive rotations, and the spiral directions of 1 spiral metal wire are all negative rotations.

As shown in fig. 8, a stent was finally obtained, which comprised a cylindrical tubular stent and 2 helical wires; the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket; the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire is only sleeved in one section of the cylindrical tubular support in a penetrating mode, and the penetrating position of the spiral metal wire are located in a settling arc of the cylindrical tubular support; the spiral metal wires with opposite spiral directions are symmetrically distributed; the radial force of the section where the spiral wire is located in the stent is 1.8 times that of the cylindrical tubular stent 1 prepared in the step (1) (the radial compression performance is measured by using an RX550 dynamometer, and the radial force is taken as the compression force when the diameter is compressed to 50% of the initial diameter, the radial force of the cylindrical tubular stent is 28N, and the radial force of the section where the spiral wire is located in the stent is 51N).

Claims

1. A stent comprising a cylindrical tubular stent and a single or plurality of helical wires;

the central axis of the spiral metal wire spiral is superposed with the central axis of the cylindrical tubular bracket;

the spiral metal wire is sleeved in the whole area of the cylindrical tubular bracket in a penetrating way, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular bracket; or the cylindrical tubular support is divided into a plurality of sections along the length direction, the spiral metal wire only penetrates and is sleeved in one section of the cylindrical tubular support, and the penetrating position of the spiral metal wire are positioned in a settling arc of the cylindrical tubular support.

2. The stent of claim 1 wherein the weave structure of the cylindrical tubular stent is weft-knitted plain weave, weft-knitted rib weave, weft-knitted interlock weave, weft-knitted links-links or weft-knitted tuck stitches.

3. The stent of claim 1, wherein the cylindrical tubular stent is made of one or more of nickel-titanium alloy, medical stainless steel, cobalt-chromium alloy or magnesium alloy.

4. A stent according to claim 1 wherein the cylindrical tubular stent has a length of 50 to 250mm and an inner diameter of 10 to 25mm and the single or single wires comprising the cylindrical tubular stent have a diameter of 0.035 to 0.2 mm.

5. A stent according to claim 4, wherein the helical wires have a diameter of 0.035 to 0.3mm, a number of 1 to 10, a pitch of 5 to 100mm, and a helical direction of either a forward or reverse rotation.

6. A stent according to claim 5, wherein the number of helical wires is d, d is an even number, and wherein the helical directions of d/2 helical wires are all positive turns and the helical directions of d/2 helical wires are all negative turns.

7. The stent of claim 1, wherein the helical wire is made of one or more of nitinol, stainless steel, cobalt-chromium alloy, or magnesium alloy.

8. A stent according to claim 1 wherein the helical wire is threaded periodically through the cylindrical tubular stent over an entire area or section thereof, wherein n is the number of longitudinal rows of coils between the entry and exit locations of the helical wire, m is the number of transverse rows of coils between the entry and exit locations of the helical wire, n is less than the number of total longitudinal rows of the cylindrical tubular stent, and m is less than the number of total transverse rows of the cylindrical tubular stent.

9. A stent according to claim 1 wherein the segment of helical wire has a radial force of 1.4 to 6.6 times that of the cylindrical tubular stent.

10. A method of making a scaffold according to any one of claims 1 to 9, comprising the steps of:

(1) weaving a single or single-stranded metal wire into a cylindrical tubular support by using a circular knitting machine with a small needle cylinder diameter, wherein the needle cylinder diameter of the circular knitting machine is 15-35 mm, and the number of needles is 12-50;

(3) sleeving the semi-finished product on a core rod, fixing two ends of the core rod, performing heat setting, and demolding to obtain a support;

the heat setting time is 5-30 min each time.