CN112545708A

CN112545708A - Intravascular stent structure

Info

Publication number: CN112545708A
Application number: CN202011517226.0A
Authority: CN
Inventors: 汪立; 蔡涛; 王君毅; 张晨朝
Original assignee: Shanghai Baixin'an Biotechnology Co ltd
Current assignee: Shanghai Baixin'an Biotechnology Co ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-03-26

Abstract

The invention relates to the field of intravascular stents, in particular to an intravascular stent structure. The intravascular stent structure comprises a degradable elastic film and a stent sleeved on the degradable elastic film, the stent is an internal hollow tubular structure with a hollowed surface, the stent comprises annular strips and linear connecting rods perpendicular to the annular strips, and the annular strips are arc-shaped and wave-shaped.

Description

Intravascular stent structure

Technical Field

The invention relates to the field of intravascular stents, in particular to an intravascular stent structure.

Background

The intravascular stent is an intelligent medical appliance which is used for placing an internal stent in a lesion section on the basis of the expansion and the forming of a lumen saccule so as to support a blood vessel at a stenotic occlusion section, reduce the elastic retraction and the reshaping of the blood vessel and keep the blood flow of a lumen smooth. Wherein, some stents also have the function of preventing restenosis, and are mainly classified into coronary stents, cerebrovascular stents, renal artery stents, aortic stents, etc.

The current mainstream intravascular stent deployment mode is a balloon expansion mode. Therefore, the intravascular stent has no elasticity and needs to be attached to the blood vessel by expanding the balloon to a certain diameter value, so the intravascular stent has the problems of poor flexibility and inconvenient use.

In addition, most of the current markets are single stent structures, after the stent rods are implanted into blood vessels, the stent rods can protrude out of the inner walls of the blood vessels, and blood flow easily forms turbulence after passing through the stent rods to cause platelet accumulation and thrombus in the stent. The membrane of the covered stent still needs to be fixed on the stent in the forms of sewing, bonding, hot melting and the like at present, and the process for fixing the membrane can damage the degradable stent body when being applied to the degradable stent.

Disclosure of Invention

In order to solve the technical problem, the invention provides an intravascular stent structure, which comprises a degradable elastic film and an intravascular stent sleeved on the degradable elastic film. The inner support is the inside hollow tubular structure of surface fretwork, and the external diameter of degradable elastic film is more than or equal to the internal diameter of inner support, consequently need not special connection processing, and degradable elastic film can rely on its self elasticity to support and blood vessel continuously hug closely, can assist on the one hand and provide support performance, and on the other hand forms the glossy thin layer of one deck at the support internal surface, prevents the formation of acute thrombus.

An intravascular stent structure comprises a degradable elastic film and a stent sleeved on the degradable elastic film, wherein the stent is of an internal hollow tubular structure with a hollowed surface, the stent comprises annular strips and linear connecting rods perpendicular to the annular strips, and the annular strips are arc-shaped and wave-shaped.

Preferably, the number of the annular strips is multiple, and the annular strips are arranged at equal intervals.

Preferably, the annular strip comprises a plurality of convex arcs and concave arcs, and the convex arcs and the concave arcs are alternately arranged at intervals.

Preferably, the convex arcs and the concave arcs have the same depth.

Preferably, the number of convex arcs and concave arcs on each annular strip is the same, and is an even number.

Preferably, the connecting rods are arranged at equal intervals between two adjacent annular strips.

Preferably, the connecting rod is arranged between the convex arcs of two adjacent annular strips.

Preferably, the number of the connecting rods between two adjacent annular strips is half of the number of the convex arcs, and the connecting rods are arranged at equal intervals.

Preferably, the surface of the degradable elastic film is coated with heparin.

Preferably, the thickness of the degradable elastic film is 10 to 25 μm.

Preferably, the outer diameter of the degradable elastic film is more than or equal to the inner diameter of the inner support.

Has the advantages that:

(1) the inner stent of the intravascular stent structure is an internal hollow tubular structure with a hollowed surface, the outer diameter of the degradable elastic film is larger than or equal to the inner diameter of the inner stent, the degradable elastic film can continuously cling to the stent and a blood vessel by virtue of the elasticity of the degradable elastic film, so that the stent support performance can be assisted to be provided, and a smooth film layer is formed on the inner surface of the stent to prevent acute thrombosis.

(2) The degradable elastic film of the intravascular stent structure can be degraded within 6 months, the intima of the blood vessel can gradually cover the inner wall of the whole film after the degradable elastic film is implanted to gradually replace the film, the intima covering is generally completed within 10 days, and the inner surface of the stent is smooth and flat in the whole process, so that the risk of thrombus in the stent is greatly degraded.

(3) The degradable elastic film of the intravascular stent structure is heparinized, and the surface of the film is coated with heparin to form the liver of the filmPerforming a neutralization treatment, controlling the heparin amount at 100-²The membrane can be released within 10 days, and the heparinized membrane can play an anticoagulation role in a human body and prevent the formation of thrombus in the stent.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly described below, the drawings described below are only some embodiments of the present invention, and it is obvious to those skilled in the art that other drawings can be obtained based on the drawings without creative efforts.

Fig. 1 is a schematic structural view of an intravascular stent structure according to embodiment 1 of the present invention;

the numbering in the figure is as follows:

1. a degradable elastic film; 2. an inner support; 3. an annular strip; 4. a connecting rod; 4-1, a first connecting rod; 4-2, a second connecting rod; 5. a convex arc; 6. a concave arc.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

Fig. 1 shows an intravascular stent structure embodied according to an embodiment of the present invention, which includes a degradable elastic film 1 and a stent 2 sleeved thereon, wherein the stent 2 is a hollow tubular structure with a hollow surface, the stent 2 includes annular strips 3 and linear connecting rods 4 perpendicular to the annular strips 3, and the annular strips 3 are in the shape of circular arc waves.

The degradable elastic film 1 is made of elastic materials, the outer diameter of the degradable elastic film 1 is preferably larger than or equal to the inner diameter of the inner support 2, the degradable elastic film 1 can be continuously attached to the inner support 2 and the blood vessel by means of elasticity of the degradable elastic film 1 without external force or special connection processing, and damage to the degradable elastic film 1 body in the processing process is well avoided.

When the stent is manufactured into a finished product, radial pressure is required to be applied to the stent to compress the stent to 20-30% of the initial diameter, so that the stent has smaller volume and is convenient to store. During the use process, after the intravascular stent 2 enters a human body, the intravascular stent 2 is expanded from the finished diameter to the use diameter by expanding the balloon, and the use diameter is 70-80% of the initial diameter. Due to the existence of the degradable elastic film 1, the acute thrombus formed by the intersection of the blood flow and the blood vessel in which the inner stent 2 is exposed is avoided, and the film with a smooth surface is not easy to stay the platelet, thereby greatly reducing the risk of the thrombus in the inner stent 2.

The inner support 2 can be integrally formed or can be formed by carving a tube in a laser cutting manner, and the material of the inner support 2 is also degradable, for example, polylactic acid.

In addition, rapamycin or paclitaxel antiproliferative drug can be further coated on the surface of the inner stent 2 by a spraying method, and the drug can be gradually dissolved out after the film is degraded, thereby inhibiting cell proliferation.

Preferably, the annular strips 3 are arc-shaped and wave-shaped, and the annular strips 3 are arranged at equal intervals; the arc wave shape can be expanded to a larger diameter when the balloon is inflated, and the inflated size can be maintained stably by arranging the annular strips 3 at equal intervals.

The circular arc wave-shaped annular strip 3 preferably comprises a plurality of convex arcs 5 and concave arcs 6, and the convex arcs 5 and the concave arcs 6 are alternately arranged at intervals. The convex arc 5 and the concave arc 6 may have the same or different depths, and in order to make the force applied in each direction the same when they are expanded, it is preferable that the convex arc 5 and the concave arc 6 have the same depth and the same arc.

Preferably, each annular strip 3 on the inner support 2 has the same shape and is arranged in parallel with each other, the convex arcs 5 or the concave arcs 6 of two adjacent annular strips 3 are on the same horizontal line, and the number of the convex arcs 5 and the number of the concave arcs 6 of each annular strip 3 are the same and are even numbers.

Preferably connecting rod 4 is equidistant between two adjacent annular strips 3 and is arranged, and connecting rod 4 connects a plurality of annular strips 3 each other and forms the hollow tubular structure of fretwork, when using, through connecting rod 4 with further homodisperse of bulging force to the all directions of hollow tube.

Further, it is preferable that the connecting rods 4 are disposed between the convex arcs 5 of the adjacent two annular strips 3, and the number of the connecting rods 4 between the adjacent two annular strips 3 is half of the number of the convex arcs 5, and the connecting rods are arranged at equal intervals. For example, when the number of the convex arcs 5 on each annular bar 3 is 6, the number of the corresponding connecting rods 4 arranged on the convex arcs 5 is 3, and because of the equidistant arrangement, it can be understood that the connecting rods 4 are not arranged on the other 3 convex arcs 5.

Further, it is preferable that the connecting rods 4 between the adjacent 3 annular strips 3 are offset from each other; it is further preferred that the connecting rod 4 comprises a plurality of first connecting rods 4-1 and a plurality of second connecting rods 4-2 arranged in a spaced-apart and staggered manner with respect to each of the plurality of first connecting rods 4-1, and such a staggered manner not only makes the inner frame more easily expandable to some extent, but also reduces the overall weight thereof, thereby facilitating the use thereof.

The outer diameter of the degradable elastic film 1 is adjusted according to the inner diameter of the inner support 2, and generally the outer diameter of the degradable elastic film 1 is required to be more than or equal to the inner diameter of the inner support 2; the degradable elastic film 1 can be prepared by any method conventionally used in the art, for example, an extruded tube of an elastomer is obtained by an extrusion method, the extruded tube is blown to a proper size by a high-temperature blowing method, the thickness of the film wall is controlled by controlling the temperature and the blowing pressure, the outer diameter of the degradable elastic film 1 is ensured to be larger than or equal to the inner diameter of the inner stent, and finally the film with a proper length is cut, wherein the length is generally larger than the length of the inner stent in the longitudinal direction, so as to ensure that the inner stent is uniformly expanded as a whole.

The degradable elastic film needs to be controlled to be degraded within 6 months, the intima of the blood vessel can gradually cover the inner wall of the whole film after being implanted to gradually replace the film, the intima covering is generally completed within 10 days, the inner surface of the stent is smooth and flat in the whole process, so that the risk of thrombus in the stent is greatly degraded, a semi-crystalline polymer is generally selected as an elastomer raw material, and the IV value is controlled to balance the mechanical property and the degradation period of the elastomer.

For example, the material of the degradable elastic film 1 may be any one of polydioxanone, poly (glycolide-caprolactone), poly (glycolide-trimethylene carbonate), polyglycolide, and poly (glycolide-L-lactide). The relevant experimental parameters for these several materials are listed in the table below.

Example 1

As shown in fig. 1, embodiment 1 of the present invention provides an intravascular stent structure, which includes a degradable elastic thin film 1 and a stent 2 sleeved thereon, where the stent 2 is an internal hollow tubular structure with a hollow surface, and the stent 2 includes annular strips 3 and linear connecting rods 4 perpendicular to the annular strips 3, and the annular strips 3 are in the shape of circular-arc waves.

The inner stent 2 is formed by carving polylactic acid pipes in a laser cutting mode, and rapamycin or paclitaxel antiproliferative medicines can be further coated on the surface of the inner stent 2 by a spraying method.

The shape of annular strip 3 is circular arc wave, and the quantity of annular strip 3 is a plurality of, and equidistant range. The circular arc wave-shaped annular strip 3 comprises a plurality of convex arcs 5 and concave arcs 6, the convex arcs 5 and the concave arcs 6 are alternately arranged at intervals, the depth of the convex arcs 5 is the same as that of the concave arcs 6, and the radian of the convex arcs 5 is the same as that of the concave arcs 6.

Each annular strip 3 on the inner support 2 is identical in shape and arranged in parallel, the convex arcs 5 or the concave arcs 6 of two adjacent annular strips 3 are on the same horizontal line, and the convex arcs 5 and the concave arcs 6 of each annular strip 3 are identical in number and are even in number.

The connecting rods 4 are arranged between the two adjacent annular strips 3 at equal intervals, and the connecting rods 4 connect the annular strips 3 mutually to form a hollow tubular structure. The connecting rods 4 are arranged between the convex arcs 5 of the two adjacent annular strips 3, the number of the connecting rods 4 between the two adjacent annular strips 3 is half of the number of the convex arcs 5, and the connecting rods are arranged at equal intervals.

The connecting rods 4 between the adjacent 3 annular strips 3 are staggered with each other; it is further preferred that the connecting rod 4 comprises a plurality of first connecting rods 4-1 and a plurality of second connecting rods 4-2 arranged in a spaced-apart offset arrangement with respect to each of the plurality of first connecting rods 4-1.

The outer diameter of the degradable elastic film 1 is larger than or equal to the inner diameter of the inner support 2, the degradable elastic film 1 can be prepared by any method conventionally used in the field, for example, an elastomer extrusion pipe is obtained by an extrusion method, then the extrusion pipe is blown to a proper size by a high-temperature blowing method, the wall thickness of the film is controlled by controlling the temperature and the blowing pressure, the outer diameter of the degradable elastic film 1 is ensured to be larger than or equal to the inner diameter of the inner support, and finally the film with a proper length is cut.

The material of the degradable elastic membrane 1 may be poly (glycolide-caprolactone).

Claims

1. An intravascular stent structure is characterized by comprising a degradable elastic film and a stent sleeved on the degradable elastic film, wherein the stent is of an internal hollow tubular structure with a hollowed surface, and comprises annular strips and linear connecting rods perpendicular to the annular strips, and the annular strips are in arc wave shapes.

2. The endovascular stent structure of claim 1, wherein the number of circumferential strips is multiple and equally spaced.

3. The endovascular stent structure of claim 2, wherein the circumferential strip comprises a plurality of convex arcs and concave arcs having the same depth, and the convex arcs and the concave arcs are alternately spaced.

4. The intravascular stent structure of claim 3, wherein the number of convex arcs and concave arcs on each annular bar is the same and is an even number.

5. The endovascular stent structure of claim 4, wherein the connecting rods are arranged at equal intervals between two adjacent circumferential strips.

6. The intravascular stent structure of claim 5, wherein the connecting rods are disposed between the convex arcs of two adjacent annular bars.

7. The endovascular stent structure of claim 6, wherein the number of connecting rods between two adjacent circumferential strips is half of the number of convex arcs, and the connecting rods are arranged at equal intervals.

8. The intravascular stent structure of any one of claims 1-7, wherein the degradable elastic membrane is surface coated with heparin.

9. The intravascular stent structure of claim 8, wherein the degradable elastic membrane has a thickness of 10-25 μm.

10. The endovascular stent structure of claim 9, wherein the degradable elastic membrane has an outer diameter greater than or equal to an inner diameter of the stent.