CN117426915A - Woven mesh tube support and manufacturing method thereof - Google Patents

Abstract

The invention discloses a woven mesh tube support and a manufacturing method thereof, wherein the woven mesh tube support comprises N sections of woven mesh tubes, the woven mesh tubes are formed by weaving woven wires, N is more than or equal to 2, N is a natural number, and each section of woven mesh tube is provided with a first end and a second end which are oppositely arranged along the axial direction of the woven mesh tube; the second end of the i-th section of the woven mesh tube is partially connected with the first end of the i+1-th section of the woven mesh tube around the circumferential direction or indirectly connected through a flexible piece, a movable allowance is formed between the i-th section of the woven mesh tube and the i+1-th section of the woven mesh tube, a blood flow channel is formed in the bracket, i is more than or equal to 1 and less than or equal to N-1, and i is a natural number. Because the adjacent two woven mesh tubes have a movable allowance, the two woven mesh tubes can freely move relative to each other, the obstruction of the stent to blood vessels is reduced, and the stent fracture caused by overlarge local stress of the stent is avoided.

Description

Woven mesh tube support and manufacturing method thereof

Technical Field

The invention belongs to the technical field of medical appliances, and particularly relates to a woven mesh tube support and a manufacturing method thereof.

Background

Atherosclerotic plaque formation, arterial medial degeneration, secondary thrombosis, etc. cause lumen stenosis or occlusion, leading to lower limb ischemia symptoms, lower limb arteriosclerotic occlusion is a common peripheral vascular disease. Lower limb arteriosclerotic occlusive disease can be classified into three categories according to the range of lesion involvement: main-iliac artery lesions, femoral-popliteal artery lesions, popliteal artery lesions (i.e., below-knee artery lesions). At present, percutaneous transluminal angioplasty (Percutaneous Transluminal Angioplasty, PTA) is the first choice method for treating the arteriosclerosis obliterans under the knee, and has better effects in improving clinical symptoms, promoting ulcer and gangrene healing, reducing amputation rate and the like. To maintain patency of the vessel lumen and patency of the blood, a method of implanting an arterial metallic stent is generally employed.

Due to the small diameter of the blood vessel at the position below the knee, the restenosis probability after PTA treatment is high, and the implanted stent needs to ensure certain radial supporting force and overcome the mechanical factors such as chronic external expansion force, low shearing force and the like. However, the existing arterial stents often have the following problems:

the long support is excessively implanted easily in the implantation process, and the support can fracture and cause human body massive hemorrhage when excessively obstructing the bending of the knee in normal use.

Therefore, improvements are needed.

Disclosure of Invention

The invention provides a woven type network management support and a manufacturing method thereof, aiming at the problems that the support in the prior art is long in length, easy to excessively implant in the implantation process, excessively obstruct the bending of the knee in normal use, and cause massive hemorrhage of the human body due to fracture of the support in severe cases, and the like.

The bracket comprises N sections of woven net pipes, wherein the woven net pipes are formed by weaving woven wires, N is more than or equal to 2, N is a natural number, and each section of woven net pipe is provided with a first end and a second end which are oppositely arranged along the axial direction of the woven net pipe;

the second end of the i-th section of the woven mesh tube is partially connected with the first end of the i+1-th section of the woven mesh tube around the circumferential direction or indirectly connected through a flexible piece, a movable allowance is formed between the i-th section of the woven mesh tube and the i+1-th section of the woven mesh tube, a blood flow channel is formed in the bracket, i is more than or equal to 1 and less than or equal to N-1, and i is a natural number.

Because the two woven mesh tubes are partially connected in the circumferential direction or connected through the flexible piece, the two woven mesh tubes naturally generate activity allowance.

The support is implanted into a human body blood vessel, particularly a human body below knee, and when a human body moves, the two adjacent woven mesh pipes have a movable allowance, so that the two woven mesh pipes can be bent relatively freely, the obstruction of the support on the blood vessel is reduced, and meanwhile, the fracture of the support caused by overlarge local stress of the support can be effectively avoided.

In one embodiment, the surface of the woven mesh tube is provided with a plurality of diamond-like woven meshes;

the part of the rhombic-like woven meshes of the second end of the i-th woven mesh tube around the circumferential direction is mutually Kong Kongxiang buckled with the part of the rhombic-like woven meshes of the first end of the i+1-th woven mesh tube around the circumferential direction.

In an embodiment, the woven mesh tube of the ith section is connected with the woven mesh tube of the (i+1) th section at only one place around the circumferential direction;

or, the i-th section of the woven mesh tube is connected with the i+1-th section of the woven mesh tube at a plurality of positions around the circumferential direction, and the positions of the connections are mutually separated around the circumferential direction of the woven mesh tube to form a movable allowance.

In one embodiment, the flexible member is a torsion spring.

In an embodiment, the second end of the i-th section of the woven mesh tube is connected to the first end of the i+1-th section of the woven mesh tube by a large torsion spring, and the large torsion spring is coiled along the radial direction of the woven mesh tube and extends along the axial direction of the woven mesh tube.

In an embodiment, the second end of the i-th section of the woven mesh tube is connected to the first end of the i+1-th section of the woven mesh tube through a plurality of small torsion springs, the small torsion springs are arranged along the circumferential direction of the support and are spaced apart from each other, and the spiral diameter of the small torsion springs is smaller than the diameter of the woven mesh tube.

In one embodiment, the whole of the N-section woven mesh tube connected stent comprises:

the compact section is provided with a first knitting density and is positioned at the middle section of the knitting type net management support;

two sparse sections with second weaving density positioned at two ends of the weaving type network management support, wherein the first weaving density is larger than the second weaving density;

and the two ends of the transition section are respectively and integrally connected with one end of the compact section and one end of the sparse section, and the knitting density of the transition section gradually transits from the first knitting density of the compact section to the second knitting density of the sparse section.

In one embodiment, the dense section has a first diameter;

the sparse segment has a second diameter, the second diameter being greater than the first diameter;

the diameter of the transition section gradually transitions from a first diameter of the dense section to a second diameter of the sparse section.

In one embodiment, the surface of the woven mesh tube support is provided with a plurality of diamond-like woven meshes;

the diamond-like woven mesh of the dense section has a first mesh area;

the diamond-like woven mesh of the sparse segment has a second mesh area, the second mesh area being greater than the first mesh area;

the area of the diamond-like woven mesh of the transition section gradually transitions from the first mesh area of the dense section to the second mesh area of the sparse section.

In one embodiment, the number of diamond-like woven mesh in the circumferential direction of the dense segment, sparse segment, and transition segment remains uniform.

The invention also provides a manufacturing method of the woven mesh tube support, which comprises the following steps:

s1, providing a cylindrical mold, wherein m rows and n columns of limit nails are embedded in the surface of the cylindrical mold, and m and n are more than or equal to 2;

s2, fixing one end of the braided wire on the cylindrical die and facing the first end of the cylindrical die;

s3, spirally winding the braided wires sequentially from the gaps of two adjacent limit nails at the first end of the surface of the cylindrical die to the gaps of two adjacent limit nails at the second end, and bypassing the limit nails at the second end of the cylindrical die to finish the forward line;

s4, continuously reversely spirally winding the braided wire in the step S2 between the gaps of two adjacent limit nails and returning to the first end of the cylindrical die, and bypassing the limit nails at the first end of the cylindrical die to finish reverse wiring;

s5, repeating the step S3 and the step S4 for a plurality of times to obtain a metal wire braided fabric with a flat net surface;

s6, performing heat setting on the metal wire braided fabric to obtain a braided net pipe;

s7, welding torsion springs between two adjacent sections of woven mesh tubes to form a woven mesh tube support;

or, the steps S5 to S7 are replaced by the following steps:

a5, repeating the step S3 and the step S4 for a plurality of times to obtain an ith section of woven mesh tube, wherein the surface of the woven mesh tube is provided with a plurality of diamond-like woven meshes;

a6, adopting braiding wires to penetrate through one or more diamond-like braiding meshes of one end of the ith section of braiding net pipe far away from the first end in the axial direction, and repeating the steps S3 and S4 to obtain an (i+1) th section of braiding net pipe, wherein i is a natural number larger than 1;

a7, repeating the step A6 for M times, wherein M is a natural number;

a8, connecting a plurality of woven mesh pipes to form a woven mesh pipe bracket embryonic form;

and A9, performing heat setting on the woven mesh tube support prototype to obtain the woven mesh tube support.

In one embodiment, the following specific steps are performed in the heat setting of the woven mesh tube scaffold blank:

performing primary heat setting on the obtained woven mesh tube bracket embryonic form, and removing the limit nails on the cylindrical die after cooling to obtain an intermediate product;

penetrating the intermediate product into a secondary die, and performing secondary heat setting and cooling to obtain the woven mesh tube bracket;

the secondary die is a cylinder with a narrow middle section and wide two ends. Preferably, m is a natural number of 3 to 6, and n is a natural number of 6 to 12.

The invention has the positive progress effects that:

1. the woven mesh tube support is smaller in overall length and diameter, the second diameter of the sparse sections at the two ends is larger than the first diameter of the middle dense section, the sparse sections at the two ends can be fixed in the inner wall of a blood vessel through the sparsity at the two ends, the middle dense section is only in contact with the inner wall of the blood vessel, and no larger radial pressure is applied to the inner wall of the blood vessel, so that the stimulation of the support to the inner wall of the blood vessel is reduced. In addition, the middle compact section has stronger radial supporting force due to denser braiding, and can keep blood vessels unobstructed.

2. The invention is a high-density braided mesh tube support, the braiding density of a dense section is obviously higher than that of sparse sections at two ends, and two transition sections with gradually transitional density, diameter and mesh area are arranged, so that the radial supporting force, flexibility and fatigue resistance of the braided mesh tube support are enhanced, the braiding density increase of the middle dense section is favorable for uniform skinning in the braided mesh tube support, the chronic external expansion force is reduced, the damage to the inner wall of a blood vessel is small, and the probability of restenosis caused by angiogenesis inflammatory reaction and the probability of fatigue fracture of the support are reduced.

3. The woven mesh tube support can be used for connecting a plurality of woven mesh tubes, and torsion springs can be arranged on the support, so that the radial supporting force and fatigue resistance of the support are ensured, the flexibility of the support is greatly enhanced, and any torsion deformation possibly occurring in the woven mesh tube support is met. Compared with the existing stent, the stent of the invention has small stimulation to endothelial cells in the torsional deformation process because of radial compression, axial stretching, twisting, bending and other deformation on the woven mesh tube stent caused by squatting or other bending of the below-knee artery, thereby reducing the inflammation incidence rate caused by vascular injury.

Drawings

Fig. 1 is a schematic structural view of a woven mesh tube in the woven mesh tube support of the present invention when the woven mesh tube is connected by Kong Kongxiang fasteners;

FIG. 2 is an enlarged view of a portion of FIG. 1;

fig. 3 is a schematic structural view of the woven mesh tube stent of the present invention when the woven mesh tube is connected by a mesh knot and positioned in an artery vessel below the knee;

fig. 4 is a schematic structural view of the woven mesh tube holder of the present invention when the mesh tube holes are fastened and connected and positioned in an arterial vessel at the knee;

fig. 5 is a schematic view of the structure of the woven mesh tube support of the present invention when the woven mesh tube is connected by a large torsion spring and positioned in the artery below the knee;

FIG. 6 is a schematic view of the structure of the woven mesh tube support of the present invention when the woven mesh tube is connected by a large torsion spring and positioned in an arterial vessel at the knee;

fig. 7 is a schematic structural diagram of the woven mesh tube of the present invention when connected by a small torsion spring;

FIG. 8 is an enlarged view of a portion of FIG. 7;

FIG. 9 is a schematic view of a cylindrical mold used in braiding a stent;

fig. 10 is a schematic view of the structure of the stent when the braid wires are wound around the cylindrical mold.

Reference numerals illustrate: 60. weaving a net pipe; 50. knitting meshes like diamond; 40. a torsion spring; 41. a large torsion spring; 42. a small torsion spring; 10. a dense section; 20. a sparse segment; 30. a transition section; 70. a cylindrical mold; 80. a blood vessel; 90. weaving filaments; 101. activity margin.

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.

In the present invention, "Kong Kongxiang buckle" means "ring-and-ring buckle", and "axial" means a direction between two sparse segments, and "radial" means a direction perpendicular to the axial direction.

As shown in fig. 1 to 6, the woven mesh tube support of the present invention specifically includes N-section woven mesh tube 60, N is greater than or equal to 2 and N is a natural number, the woven mesh tube 60 is formed by weaving a woven wire 90, the woven wire 90 is a soft metal wire such as nickel-titanium alloy, platinum-iridium alloy, etc., and the diameter of the nickel-titanium alloy metal wire or platinum-iridium alloy metal wire is in the range of 0.08-0.16mm. The length of the woven mesh tube 60 in the invention ranges from 15 mm to 50mm, and the diameter ranges from 3 mm to 6mm, so that the number of the woven mesh tube 60 implanted is conveniently selected according to the stenosis and blockage length of the blood vessel 80 in the treatment process, and the excessive implantation caused by the overlong stent, namely the excessive extension of the stent to the vascular end benefit, is avoided. The woven mesh tube support is formed by manually weaving and heat setting a metal wire on a mould, and the density of the diamond-like woven meshes 50 on the surface of the woven mesh tube support is the weaving density.

Specifically, each section of the woven mesh tube 60 has a first end and a second end disposed opposite each other in the axial direction thereof. It should be noted that the shapes of the woven mesh tubes 60 may be identical, but may differ somewhat. Of course, the shape of the first and second ends of each woven mesh tube 60 may or may not be the same.

The second end of the i-th section of woven mesh tube 60 is partially connected with the first end of the i+1-th section of woven mesh tube 60 around the circumferential direction or indirectly connected through a flexible member, and a blood flow channel is formed in the bracket, i is more than or equal to 1 and less than or equal to N-1, and i is a natural number. When the stent is implanted in the blood vessel 80, a channel for blood flow therethrough is formed in the blood vessel 80, thereby preventing thrombus or wounds or the like present on the wall of the blood vessel 80 from clogging the blood vessel and affecting the flow of blood.

Specifically, along the axial direction of the woven mesh tube support, a movable allowance 101 is arranged between two adjacent sections of woven mesh tubes 60.

Generally, since the human body needs to move, the stent is implanted into the blood vessel 80 to deform along with the blood vessel 80, especially, the below-knee artery blood vessel 80 is implanted into the below-knee artery blood vessel 80, and the below-knee artery blood vessel 80 is not only very small, but also has very large moving amount, so that the stent easily causes obstruction to the below-knee artery blood vessel 80. In addition, due to the great activity of the artery 80 below the knee, the stent is easy to break due to excessive bending, and once the stent breaks, the blood vessel 80 (especially the artery 80) is easy to puncture, so that the human body bleeds, and the life can be endangered in serious cases.

In this embodiment, since the stent is divided into one section of woven mesh tube 60 and the adjacent two sections of woven mesh tube 60 have a movable margin 101 therebetween, when the stent is bent or twisted along with the blood vessel 80 of the human body, a movable space exists between the adjacent two sections of woven mesh tube 60, so that the stent is not easily broken and the obstruction to the blood vessel 80 can be reduced.

In this embodiment, there is an activity margin 101 between any two adjacent sections of woven mesh tube 60. Thus the movement of the bracket is more flexible.

Specifically, each woven mesh tube 60 is woven by using the woven filaments 90, and each woven mesh tube 60 is woven to form a plurality of diamond-like woven meshes 50. The braided wire 90 may be a relatively soft wire such as a nickel titanium alloy wire or a platinum iridium alloy wire. Since each woven mesh tube 60 is formed by weaving, the supporting force is good, and in addition, since the activity allowance 101 is arranged between two adjacent woven mesh tubes 60, the flexibility is also good.

It should be noted that, in the present application, the number, length and diameter of the woven mesh tube 60 may be adjusted according to needs, for example, the woven mesh tube 60 may have four sections, five sections or more, so that a stent with a very long length may be spliced, and after the stent is implanted into the below-knee blood vessel 80, the stent not only can meet the requirements in length, but also has very high supporting force and flexibility.

As shown in fig. 1 to 4, in order to have a play allowance 101 between two adjacent sections of the woven mesh tube 60, the second end of the woven mesh tube 60 of the i-th section has a part of diamond-like woven mesh holes 50 around the circumferential direction, and the second end of the woven mesh tube 60 of the i-th section and the part of diamond-like woven mesh holes 50 of the first end of the woven mesh tube 60 of the i+1 section around the circumferential direction are fastened to each other Kong Kongxiang (i.e., are fastened to each other around the ring).

There are a number of situations for such a snap connection: for example, as shown in fig. 1 to 4, the i-th section of the woven mesh tube 60 is connected with the i+1-th section of the woven mesh tube 60 only at one place around the circumferential direction, specifically, the second end of the i-th section of the woven mesh tube 60 is provided with two or three adjacent rhomboid woven meshes 50 which are correspondingly buckled with Kong Kongxiang of the two rhomboid woven meshes 50 of the i+1-th section of the woven mesh tube 60, while the other rhomboid woven meshes 50 are separated from each other, the stent in fig. 1 to 2 is in a natural state, so that the other rhomboid woven meshes 50 are meshed together, and no clear gap exists between the other rhomboid woven meshes when the stent is implanted into the below-knee blood vessel 80, as shown in fig. 3 and 4, the stent is also buckled, and thus the other rhomboid woven meshes 50 are separated from each other. And because only one place is connected together, when the bracket is bent, the two woven webmaster 60 can flexibly and relatively move, and the phenomenon that the bracket is broken to cause the bracket to puncture the blood vessel 80 can be effectively avoided.

Of course, it should be emphasized that the specific example described above is a connection of two diamond-like woven meshes 50, but in some embodiments, there may be one or three, or even more, without departing from the scope of the present invention.

In addition, in some embodiments, the i-th knitted mesh tube 60 is connected to the i+1-th knitted mesh tube 60 at a plurality of positions around the circumferential direction, and the positions of the connections are spaced apart from each other around the circumferential direction of the knitted mesh tube 60 to form a movable allowance 101. For example, there may be two or three joints along the circumferential direction of the stent, although there may be more joints, each of which is spaced apart from the other in the circumferential direction of the stent. When the bracket is bent, a movable allowance is arranged between two adjacent woven mesh tubes 60, so that the bracket can be flexibly and relatively bent, and the bracket is prevented from being broken.

Specifically, in order to connect the holes between the two sections of the woven mesh tube 60, the manufacturing method of the bracket is as follows, after a metal wire is wound on the cylindrical mold 70 and the i section of the woven mesh tube 60 is woven by hand, when the i+1 section of the woven mesh tube 60 is woven, the i section of the woven mesh tube 60 which is woven is sleeved on the cylindrical mold 70, after the metal wire passes through one or more corresponding diamond-like woven meshes 50 at the ports of the i section of the woven mesh tube 60, the subsequent weaving process of the i+1 section of the woven mesh tube 60 is performed, and the woven mesh tube bracket formed by connecting the plurality of sections of the woven mesh tube 60 forms a complete bracket as a whole.

As another example, as shown in fig. 5 and 6, to satisfy the deformation of radial compression, axial stretching, twisting or bending, etc. that occurs when the woven mesh tube support squats down or otherwise bends in the below-knee artery vessel 80, the flexible member is a torsion spring 40, and specifically, the second end of the i-th woven mesh tube 60 is connected to the first end of the i+1-th woven mesh tube 60 by the torsion spring 40. Because the torsion spring 40 is generally softer than the woven mesh tube 60, when the stent is bent, the softer torsion spring 40 is bent, which can greatly reduce the risk of the stent being broken. And the two sections of the woven mesh tube 60 are connected through the torsion spring 40, so that the movable allowance 101 is more conveniently formed between the two sections of the woven mesh tube 60.

Specifically, as shown in fig. 5 and 6, the torsion spring 40 may be a large torsion spring 41, and it should be noted that the spiral diameter of the large torsion spring 41 is substantially identical to the diameter of the woven mesh tube 60, two ends of the large torsion spring 41 are respectively connected with one section of the woven mesh tube 60, and the large torsion spring 41 is coiled along the radial direction of the woven mesh tube 60 and extends along the axial direction of the woven mesh tube 60. As shown in fig. 5 and 6, since the large torsion spring 41 is wound in the radial direction of the mesh tube 60 and extends in the axial direction of the mesh tube 60, the large torsion spring 41 is less likely to be broken after being bent.

In another example, as shown in fig. 7 and 8, the torsion spring 40 may be a number of small torsion springs 42 that are parallel to each other. The small torsion springs 42 are enclosed into a cylindrical shape, the spiral diameter of each small torsion spring 42 is far smaller than the diameter of the woven mesh tube 60, and each diamond-like woven mesh 50 on the circumference of one end of the woven mesh tube 60 is connected with one small torsion spring 42. Of course, it is also possible that a plurality of diamond-like woven meshes 50 in the circumferential direction are connected with a small torsion spring 42 at intervals of one or a plurality of diamond-like woven meshes 50, wherein the torsion spring 40 and the woven mesh tube 60 can be connected by welding, rubber sleeve or stainless steel sleeve pressing, etc., and the torsion spring 40 can be made of stainless steel or other alloy materials. The design enhances the flexibility of the woven mesh tube support while maintaining the radial supporting force and fatigue resistance of the woven mesh tube support, and reduces the stimulation of endothelial cells during the twisting process of the support, thereby reducing the incidence of inflammation caused by the damage of the blood vessel 80.

In the present application, since the stent is divided into multiple sections, and the flexible margin 101 is provided between the woven mesh tube 60 of each section, the stent is very suitable for being implanted into the below-knee blood vessel 80, especially when the stent to be implanted is long, the stent of the present application is adopted, not only the length of the stent can be ensured, but also the supportability and the flexibility can be considered.

In addition, as shown in fig. 1, 3, 5 and 7, the woven mesh tube stent in which the plurality of woven mesh tubes 60 are connected integrally forms one dense segment 10, two sparse segments 20 and two transition segments 30.

Illustratively, the dense segment 10 of the woven mesh stent of the present invention is a small hollow cylinder, while the sparse segments 20 at both ends are large hollow cylinders.

In one aspect, as shown in FIG. 1, the diameter of the cylindrical dense section 10 is smaller than the diameter of the sparse section 20. I.e. the dense section 10 has a first diameter of approximately 3-5mm; the sparse section 20 has a second diameter of approximately 4-6mm. Because the first diameter of the dense segment 10 is smaller than the second diameter of the sparse segment 20, where the sparse segment 20 having the larger second diameter supports the arterial vessel 80, the dense segment 10 having the smaller first diameter does not exert a stronger radial pressure on the inner wall of the arterial vessel, thereby causing less interference with the below knee bending and less irritation to the inner wall of the vessel. And the sparse sections 20 at the two ends are supported on the inner wall of the arterial vessel, so that the woven mesh tube bracket can be prevented from being displaced. On the other hand, the cylindrical dense section 10 is longer in length than the sparse sections 20 at both ends. I.e. the dense section 10 has a first length of approximately 10-30mm; the sparse segment 20 has a second length of approximately 3-10mm.

The surface of the cylindrical dense segment 10 in the middle and the surface of the sparse segment 20 at both ends each have several diamond-like woven meshes 50 extending therethrough. The distribution of the number of diamond-like woven meshes 50 on the surfaces of the dense section 10 and the sparse section 20 is different depending on the number of diamond-like woven meshes 50 per unit area. The number of diamond-like woven mesh openings 50 per unit area on the surface of the cylindrical dense segment 10 is a first weave density of approximately 25-60PPI. The number of diamond-like woven mesh openings 50 on the surface of the open section 20 is a second weave density of approximately 10-20PPI. The dense section 10 with the larger first braiding density enhances the radial supporting force (the radial supporting force can keep the shape of the stent, prevent thrombus on the inner wall of a blood vessel and the like from extruding and deforming the stent), the flexibility and fatigue resistance, the braiding density of the dense section 10 in the middle is increased, the uniform skinning in the braided mesh stent is facilitated, the chronic external expansion force is reduced, and the damage to the inner wall of the blood vessel 80 is small, so that the probability of restenosis caused by inflammatory reaction of the blood vessel 80 and the probability of fatigue fracture of the stent are reduced. In a further aspect, the diamond-like woven mesh 50 of the dense segment 10 has a mesh area that is smaller than the mesh area of the sparse segment 20, i.e., the diamond-like woven mesh 50 of the dense segment 10 has a first mesh area of 2-4mm ² . The sparse segment 20 has a second mesh area of 4-6mm ² . The first mesh area of dense segment 10 is small, thereby further increasing the weave density per unit area.

As an illustration, the woven mesh tube support of the present invention has two transition sections 30, which are hollow truncated cones, having a third length of 4-8mm. The transition section 30 mainly plays a role in transition connection as the name implies, two ends of the transition section 30 are respectively and integrally connected with one end of the dense section 10 and one end of the sparse section 20, and the transition section 30 plays a role in better connecting the dense section 10 and the sparse section 20 and improving radial supporting force and fatigue resistance of the woven network management support. The knitting density of the transition section 30 gradually transits from the first knitting density of the dense section 10 to the second knitting density of the sparse section 20, the diameter gradually transits from the first diameter of the dense section 10 to the second diameter of the sparse section 20, and the mesh area gradually transits from the first mesh area of the dense section 10 to the second mesh area of the sparse section 20. Wherein the first weave density is greater than the second weave density. So that the increase of the knitting density of the middle compact section 10 is beneficial to the uniform dermatozation in the knitted mesh tube support and reduces the chronic external expansion force of the knitted mesh tube support. The first diameter is smaller than the second diameter, and the first mesh area is smaller than the second mesh area, so that a woven mesh tube support with the middle woven density higher than that of the two ends and the first diameter smaller than that of the two ends is formed. It should be noted that in some embodiments, the number of diamond-like woven meshes 50 of the dense section 10, the sparse section 20, and the transition section 30 in the circumferential direction is kept uniform, and preferably, the number of diamond-like woven meshes 50 is 6-12.

In this embodiment, as shown in fig. 5, the stent is divided into two sections. In the axial direction of the stent, each section of woven mesh tube 60 has a smaller diameter and a larger woven density at the end facing the center of the stent, but has a larger diameter and a smaller woven density at the end facing away from the center of the stent. Of course, in some embodiments, the woven mesh tube 60 may be three or more, and when the woven mesh tube 60 is three, the middle section may have the same diameter, and the two woven mesh tubes 60 at the two ends may have the structure described above when only two sections are used.

In addition, it should be emphasized that in some embodiments, the diameter and the density may be substantially the same throughout the woven mesh tube scaffold.

In addition, in one embodiment, a heat and pressure type coating film can be added on the outer surface or the inner surface of the woven type network management support, and the coating film material can be polytetrafluoroethylene or polyurethane, so that the coating film support is obtained. The woven net management stent added with the coating has the supporting function of the bare stent, and can prevent inflammation and thrombosis and restore normal blood flow through the mechanical barrier of the coating and special substances on the surface of the coating. The woven mesh tube stent for artery repair has the advantages of small trauma, quick recovery and the like.

As shown in fig. 5 to 8, the woven mesh tube support comprises a dense section 10 at the middle end of the support, two sparse sections 20 at the two ends of the support, two transition sections 30 connecting the dense section 10 and the two sparse sections 20, and a torsion spring 40 at the middle section of the support, and the surface of the woven mesh tube 60 is also provided with a plurality of diamond-like woven meshes 50.

As an illustration, the woven mesh tube stent of the present invention adopts a hand-weaving manner because the stent is easily broken due to an excessively long or large diameter, and is woven to a suitable length according to actual conditions, thereby improving the flexibility and applicability of the stent. The braided wire 90 is made of nickel-titanium alloy, platinum-iridium alloy and other softer metal wires, and the diameter of the nickel-titanium alloy metal wires or the platinum-iridium alloy metal wires ranges from 0.08 mm to 0.16mm. The stent has smaller overall length and diameter, the length range of the stent is 15-50mm, the diameter range of the stent is 3-6mm, the design is convenient for selecting the number of implanted stents according to the stenosis and blockage length of the blood vessel 80 in the treatment process, and the condition that the stent is excessively implanted in the part without an interlayer or a stenosis due to the incapability of adjusting the stent length is avoided. The woven mesh tube support is formed by manually weaving and heat setting a metal wire on a mould, and the density of the diamond-like woven meshes 50 on the surface of the woven mesh tube support is the weaving density.

The method for knitting the knitted mesh tube support comprises the following steps:

s1, providing a cylindrical mold 70 (shown in fig. 9 and 10) as a knitting mold, wherein 3 to 6 rows of limit nails are arranged on the surface of the cylindrical mold 70, 6 to 12 limit nails are arranged in each row, planes of the limit nails in each row are parallel to each other, and the number of the limit nails at the waist part and the number of the limit nails at the two ends are the same. The number of spacing rows between the spacing nails on the cylindrical die 70 is adjusted to obtain different PPI (knitting density or mesh density), the spacing nails are uniformly and fixedly connected on the surface of the die, so that the metal wires for knitting can be uniformly surrounded on the die;

s2, fixing one end of the knitting yarn 90 on the cylindrical die 70 and facing the first end of the cylindrical die 70;

s3, spirally winding the braided wire 90 from the gaps of two adjacent limit nails at the first end to the gaps of two adjacent limit nails at the second end on the surface of the cylindrical die 70 in sequence, and bypassing the limit nails at the second end of the cylindrical die 70 to finish a forward line (from top to bottom is a forward line);

s4, continuously and reversely spirally winding the braided wire 90 in the step S2 between the gaps of two adjacent limit nails and returning to the first end of the cylindrical die 70, and then bypassing the limit nails at the first end of the cylindrical die 70 to finish reverse wiring (namely reverse wiring from bottom to top); when the reverse row lines are penetrated, the staggered grid number of the limit nails is the same as the staggered grid number when the forward row lines are penetrated, so that rhomboid grids which are parallel in the same direction and reversely crossed are formed, and the rhomboid grids are rhomboid woven meshes 50;

s5, repeating the step S3 and the step S4 for a plurality of times, threading at the crossing points when the braiding wires 90 are spirally wound to form forward or reverse line, and repeatedly forming mutually restricted rhomboid-like grids at intervals of one crossing point for each threading; the metal wires are sequentially woven in a shuttling mode inside and outside the rest crossing points until the whole weaving density reaches the set density, and finally, the reverse-stitch line returns to an initial point to obtain the metal wire woven fabric with a flat net surface;

s6, performing heat setting on the metal wire braided fabric to obtain a braided net pipe 60; in the heat setting process, the metal braid may be first heat set, cooled and then removed from the spacing nails on the cylindrical mold 70 to obtain an intermediate product, and then the intermediate product is threaded into a secondary mold, and the second heat set is cooled to obtain the braid mesh tube 60. The shape of the secondary die can be adjusted according to the needs, for example, a cylinder with the same diameter at each position can be adopted, and a cylinder with one narrow end and one wide end can also be adopted.

And S7, welding the torsion spring 40 between two adjacent sections of woven mesh tube 60 to form the woven mesh tube support.

In another embodiment, the steps between S5 and S7 may be replaced by the following steps:

a5, repeating the step S3 and the step S4 for a plurality of times to obtain an ith section of woven mesh tube 60, wherein the surface of the woven mesh tube 60 is provided with a plurality of diamond-like woven meshes 50;

a6, the weaving wires 90 penetrate through a diamond-like weaving mesh 50 at a preset end of the ith weaving mesh tube 60 in the axial direction, wherein the preset end is the end of the ith weaving mesh tube 60 away from the first end of the cylindrical mold 70. Repeating the steps S3 and S4 to obtain an i+1st section of woven mesh tube 60, wherein i is a natural number greater than 1;

a7, repeating the step A6 for M times, wherein M is a natural number;

a8, connecting a plurality of woven mesh tubes 60 to form a woven mesh tube bracket embryonic form;

and A9, performing heat setting on the woven mesh tube support prototype to obtain the woven mesh tube support.

And after the support in the two embodiments is subjected to heat setting and cooling, the joint is connected by welding or pressing a rubber sleeve or a stainless steel sleeve, and the like, so that the complete woven mesh tube support is obtained.

In this embodiment i is equal to 1, then the stent comprises two sections of woven mesh tube 60, although in some embodiments i may be equal to 2, 3 or 4 or more.

Because the i+1 section of the woven mesh tube 60 is woven by adopting the weaving wires 90 to pass through the diamond-like woven mesh 50 of the i section of the woven mesh tube 60, the i section of the woven mesh tube 60 and the i+1 section of the woven mesh tube 60 can be connected by Kong Kongxiang buckles.

In addition, the specific steps of heat setting the woven net pipe bracket embryonic form are as follows:

performing primary heat setting on the obtained woven mesh tube bracket embryonic form, and removing the limit nails on the cylindrical die 70 after cooling to obtain an intermediate product; penetrating the intermediate product into a secondary die, and performing secondary heat setting and cooling to obtain the woven mesh tube bracket; the secondary die is a cylinder with a narrow middle section and wide two ends.

Because the secondary mould is a cylinder with a narrow middle and wide two ends, a bracket with a small middle diameter and a large two ends diameter is formed after the bracket is subjected to secondary heat setting.

In addition, since the middle of the stent is densely woven, the number of the cells of the knitting yarn 90 which are staggered with respect to the spacing nails can be small when the reverse line and the forward line are inserted, and the number of the cells of the knitting yarn 90 which are staggered with respect to the spacing nails can be large when the densities of the two ends of the stent are sparse.

In addition, at the same position, the staggered grid number of the limit nails is the same as the staggered grid number in the parallel and inverse crossing mode to form diamond-like grids.

Further preferably, when the braided wire 90 is helically wound to form a forward or reverse course, threading is performed at the crossing points, each time the threading is performed at one crossing point, and thus, the mutually restrained diamond-like meshes are repeatedly formed.

In this embodiment, m is a natural number of 3 to 6, and n is a natural number of 6 to 12. Of course, in some embodiments, the number may be increased or decreased accordingly.

After the support adopts the structure, the connection of the multi-section woven mesh tube 60 is ensured, a certain space is reserved for the torsional deformation of the woven mesh tube support, the axial stretching rate of the woven mesh tube support is improved, and the damage of the woven mesh tube support to endothelial cells is reduced while the stretching deformation of the below-knee artery is satisfied. After the whole woven mesh tube bracket is woven and shaped by passing through the secondary shaping die, the joint of the multi-section woven mesh tube 60 presents a plurality of annular woven meshes, so that a plurality of closed supporting units on the woven mesh tube bracket are formed, the radial supporting force of the woven mesh tube bracket is improved again, the compression deformation of the below-knee artery is born, the axial rotation space is provided while the blood vessel 80 is effectively supported, the fatigue is improved conveniently, and the woven mesh tube bracket is prevented from twisting and breaking for a plurality of times.

While the invention has been described in detail with reference to the embodiments thereof, it will be apparent to one skilled in the art that various changes in the invention may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (12)

1. The woven mesh tube support is characterized by comprising N sections of woven mesh tubes, wherein the woven mesh tubes are woven by woven wires, N is more than or equal to 2, N is a natural number, and each section of woven mesh tube is provided with a first end and a second end which are oppositely arranged along the axial direction of the woven mesh tube;

the second end of the i-th section of the woven mesh tube is partially connected with the first end of the i+1-th section of the woven mesh tube around the circumferential direction or indirectly connected through a flexible piece, a movable allowance is formed between the i-th section of the woven mesh tube and the i+1-th section of the woven mesh tube, a blood flow channel is formed in the bracket, i is more than or equal to 1 and less than or equal to N-1, and i is a natural number.

2. The woven mesh tube scaffold of claim 1, wherein the surface of the woven mesh tube has diamond-like woven mesh openings;

the part of the rhombic-like woven meshes of the second end of the i-th woven mesh tube around the circumferential direction is mutually Kong Kongxiang buckled with the part of the rhombic-like woven meshes of the first end of the i+1-th woven mesh tube around the circumferential direction.

3. The woven mesh tube scaffold of claim 2, wherein the woven mesh tube of the ith section is connected with the woven mesh tube of the (i+1) th section at only one place around the circumferential direction;

or, the i-th section of the woven mesh tube is connected with the i+1-th section of the woven mesh tube at a plurality of positions around the circumferential direction, and the positions of the connections are mutually separated around the circumferential direction of the woven mesh tube to form a movable allowance.

4. The woven mesh tube scaffold of claim 1, wherein the flexible member is a torsion spring.

5. The woven mesh tube scaffold of claim 4, wherein the second end of the woven mesh tube of section i is connected to the first end of the woven mesh tube of section i+1 by a large torsion spring that is coiled radially of the woven mesh tube and extends axially of the woven mesh tube.

6. The woven mesh tube support of claim 4, wherein the second end of the woven mesh tube of the ith section is connected to the first end of the woven mesh tube of the (i+1) th section by a plurality of small torsion springs, each of the small torsion springs being arranged in a circumferential direction of the support and spaced apart from each other, and a spiral diameter of the small torsion springs being smaller than a diameter of the woven mesh tube.

7. The woven mesh tube scaffold of claim 1, wherein the N-section woven mesh tube scaffold as a whole has:

the compact section is provided with a first knitting density and is positioned at the middle section of the knitting type net management support;

two sparse sections with second weaving density positioned at two ends of the weaving type network management support, wherein the first weaving density is larger than the second weaving density;

and the two ends of the transition section are respectively and integrally connected with one end of the compact section and one end of the sparse section, and the knitting density of the transition section gradually transits from the first knitting density of the compact section to the second knitting density of the sparse section.

8. The woven mesh tube scaffold of claim 7,

the dense section has a first diameter;

the sparse segment has a second diameter, the second diameter being greater than the first diameter;

the diameter of the transition section gradually transitions from a first diameter of the dense section to a second diameter of the sparse section.

9. The woven mesh tube scaffold of claim 7, wherein the surface of the woven mesh tube scaffold has diamond-like woven mesh openings;

the diamond-like woven mesh of the dense section has a first mesh area;

the diamond-like woven mesh of the sparse segment has a second mesh area, the second mesh area being greater than the first mesh area;

the area of the diamond-like woven mesh of the transition section gradually transitions from the first mesh area of the dense section to the second mesh area of the sparse section.

10. The woven mesh tube scaffold of claim 8, wherein the number of diamond-like woven mesh openings in the circumferential direction of the dense segments, sparse segments, and transition segments remain uniform.

11. The manufacturing method of the woven mesh tube support is characterized by comprising the following steps:

s1, providing a cylindrical mold, wherein m rows and n columns of limit nails are embedded in the surface of the cylindrical mold, and m and n are more than or equal to 2;

s2, fixing one end of the braided wire on the cylindrical die, wherein the fixed position faces to the first end of the cylindrical die;

s3, spirally winding the braided wires from the surfaces of the cylindrical dies towards the gaps of the two adjacent limit nails at the first end to the gaps of the two adjacent limit nails at the second end in sequence, and bypassing the limit nails at the second end of the cylindrical dies to finish the forward line;

s4, continuously reversely spirally winding the braided wire in the step S2 between the gaps of two adjacent limit nails and returning to the first end of the cylindrical die, and bypassing the limit nails at the first end of the cylindrical die to finish reverse wiring;

s5, repeating the step S3 and the step S4 for a plurality of times to obtain a metal wire braided fabric with a flat net surface;

s6, performing heat setting on the metal wire braided fabric to obtain a braided net pipe;

s7, welding torsion springs between two adjacent sections of woven mesh tubes to form a woven mesh tube support;

or, the steps S5 to S7 are replaced by the following steps:

a5, repeating the step S3 and the step S4 for a plurality of times to obtain an ith section of woven mesh tube, wherein the surface of the woven mesh tube is provided with a plurality of diamond-like woven meshes;

a6, adopting braiding wires to penetrate through a diamond-like braiding mesh hole of one end of the ith braiding net pipe far away from the first end in the axial direction, and repeating the steps S3 and S4 to obtain an (i+1) th braiding net pipe, wherein i is a natural number larger than 1;

a7, repeating the step A6 for M times, wherein M is a natural number;

a8, connecting a plurality of woven mesh pipes to form a woven mesh pipe bracket embryonic form;

and A9, performing heat setting on the woven mesh tube support prototype to obtain the woven mesh tube support.

12. The method of claim 11, wherein the method comprises the following specific steps of heat setting the embryonic form of the woven mesh tube scaffold:

performing primary heat setting on the obtained woven mesh tube bracket embryonic form, and removing the limit nails on the cylindrical die after cooling to obtain an intermediate product;

penetrating the intermediate product into a secondary die, and performing secondary heat setting and cooling to obtain the woven mesh tube bracket;

the secondary die is a cylinder with a narrow middle section and wide two ends.