CN215458977U - Blood vessel support - Google Patents

Abstract

The utility model discloses a vascular stent which comprises a plurality of single-ring stents, wherein the single-ring stents are arranged at intervals along the axial direction, and the single-ring stents are wavy along the axial direction while extending in the circumferential direction; the adjacent two single-ring brackets are connected through the connectors; wherein the connectors comprise two first circumferential connectors and at least one axial connector; one first circumferential connector is circumferentially connected with a wave crest of one single-ring bracket, and the other first circumferential connector is circumferentially connected with a wave trough of the other single-ring bracket; the axial connectors are connected with wave crests or wave troughs of two adjacent single-ring supports or the first circumferential connector in the axial direction, and the axial connectors are unevenly distributed in the circumferential direction. The vascular stent has different support performance and compliance performance in the circumferential direction, can better adapt to the anatomical structure of a blood vessel, and has excellent bending performance and fatigue performance.

Description

Blood vessel support

Technical Field

The utility model relates to the technical field of biomedical engineering, in particular to a vascular stent.

Background

Thoracic aorta intracavity Repair (TEVAR) is a minimally invasive interventional therapy, which is a treatment method that a femoral artery is punctured percutaneously, interventional devices such as a covered stent are conveyed to a lesion part along the femoral artery under the guidance of an imaging device, and the interlayer part in a blood vessel is isolated locally. The clinical application is very wide because of the advantages of small wound, quick recovery, avoidance of some complications of surgical operation and the like.

The aorta blood vessel presents a certain taper in the axial direction, the blood vessel diameter at the proximal end is larger, the blood vessel diameter at the distal end is smaller, Stent-derived New lacerations (SINEs) can be caused after the TEVAR operation, the SINEs refer to the incomplete matching of the straight-tube-shaped covered Stent and the tapered blood vessel shape, when the covered Stent is intervened, the distal end of the Stent is excessively opened, and larger shearing stress is generated on an aortic dissection diaphragm, so that a New laceration is initiated. Usually, before the stent graft is released in the TEVAR operation, a Restrictive Bare Stent (RBS) is preset at the distal end of the stent graft, so that the excessive opening of the distal end of the stent graft is limited and the SINE is prevented.

The existing aorta covered stent and the limiting stent have the following defects:

1. the exposed area extending outwards from the end part of the existing partial covered stent can oppress the inner wall of the blood vessel, and the risk of intimal rupture is increased. The existing part of the tectorial membrane stent is generally formed by sewing a plurality of stent single rings by a polymer film. A small section of naked stent single ring extends outwards from the proximal end or the distal end of the covered stent and is used for hooking the delivery system and adapting to the loading, pushing and releasing of the delivery system. However, the blood vessel peristalsis along with the beating of the heart, when the covered stent is completely released at the lesion site, the overhanging exposed area of the covered stent can be mutually extruded with the inner wall of the blood vessel, and even the weak blood vessel intima at the lesion site is punctured.

2. The stent apexes at the two ends of the bare stent may cause compression on the inner wall of the blood vessel, increasing the risk of intimal rupture. The two ends of the bare stent are similar to the overhanging bare sections of the covered stent, when the bare stent is completely released at a diseased region, the two ends of the bare stent can be mutually extruded with the inner wall of a blood vessel along with the peristalsis of the blood vessel, and even puncture the intima of the blood vessel of the weak diseased region.

3. The stent has a large reduction rate, i.e., the length of the tubular stent in the axial direction thereof is liable to decrease. This is often due to the poor manner of connecting the ring supports. The cause of the shortening is as follows: after the existing support is stressed axially, the connector is easy to reverse axially, so that the support is shortened axially. And the larger the axial length of the connecting body is, the larger the shortening rate is. The shortening causes two: the existing support is mostly formed by connecting multi-ring independent single-ring supports, and a connector is a metal wire or a high-molecular wire and the like. The plurality of single-ring brackets are connected into a complete bracket by winding or knotting silk threads at wave crests and wave troughs. But silk thread node takes place to slide on the support wave pole easily, and when the node slided to the wave pole middle section from the crest trough, the support not only wholly produced the shortening, and the form can produce unpredictable change moreover, and then influences the performance of whole support.

4. The bending performance of a partially bare stent is poor. After the existing part of bare stent is bent greatly, the bending cross section of the stent is distorted, and the shape of the cross section is changed from a circle to an ellipse with an acute angle. The major axis of the ellipse is larger than the inner diameter of the blood vessel at the lesion site, and the acute angle may scratch the inner wall of the blood vessel. Meanwhile, after the existing part of bare stent is bent greatly, the small bend can be folded inwards, the cross section area becomes small, and the outer surface of the existing part of bare stent cannot be well attached to the inner wall of the blood vessel.

5. At present, the number of special blood vessel stents for treating the Debakey II type is less, especially for the Debakey II type which does not need to carry out branch blood vessel reconstruction and has no involvement of dissection in the aortic arch. Because the ascending aorta is short and close to the heart, in order to prevent the detachment of the stent of the blood vessel inserted into the portion, the stent needs to have a certain length enough to cross the aortic arch to complete the anchoring. If use traditional tectorial membrane support to intervene treatment, the branch blood supply of aortic arch portion can be blocked to the polymer film, so need trompil on the film to accomplish trompil and branch vascular accurate adaptation, this has greatly increased the operation degree of difficulty.

6. The radial supporting force of the whole part of the bare stent is distributed unevenly in the axial direction, namely the radial supporting force difference of the single-ring stent and the connecting body is large. The supporting force of the existing bracket in the radial direction is provided by a single-ring bracket, the bending performance is provided by the connecting body wire, and the wire has almost no supporting force in the radial direction. This results in an uneven distribution of radial support forces for the overall stent. The single-ring stent has to have enough radial supporting force to stably anchor the whole stent in the blood vessel without sliding, so that the pressure of the single-ring stent on the inner wall of the blood vessel is far greater than that of the connecting body part, the inner wall of the blood vessel of a patient is very weak, and the single-ring stent generating the larger pressure is very likely to cause secondary damage to the inner wall of the blood vessel.

7. The mechanical property specification of the existing part of bare stent is single. According to the structural design and the manufacturing technology of the existing partial scaffold, the mechanical property of the single-ring scaffold can be adjusted only, and the mechanical property of the single-ring scaffold mainly depends on the size of the section of the wave rod and the performance of the manufacturing material. The size and specification of the section of the wave rod are fixed, and the mechanical property of the material needs to be debugged through a complex process, so that the supports with different mechanical properties are difficult to produce based on the structural design and the manufacturing technology of the existing support.

8. The existing partial bare stent is easy to generate the phenomena of eccentricity, collapse and the like of a stent ring. After the existing partial bare stent is implanted, the probability of the faults of separation, fracture, dislocation and the like of the stent rings is as high as 9.2%, particularly, the bare stent part extending to the abdominal aorta part is easy to have the phenomena of eccentricity, collapse and the like, which are caused by the lack of radial supporting force and the lack of axial supporting objects of the stent.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a vascular stent having different support properties and compliance properties in the circumferential direction, which is better adapted to the vascular anatomy, while having excellent bending properties and fatigue properties.

In order to achieve the above and other related objects, the present invention provides a vascular stent, comprising a plurality of single-ring stents arranged at intervals in an axial direction, wherein the single-ring stents undulate in the axial direction while extending in a circumferential direction;

the adjacent two single-ring brackets are connected through the connectors;

wherein the connectors comprise two first circumferential connectors and at least one axial connector;

one first circumferential connector is circumferentially connected with a wave crest of one single-ring bracket, and the other first circumferential connector is circumferentially connected with a wave trough of the other single-ring bracket;

the axial connectors are axially connected with wave crests or wave troughs of two adjacent single-ring supports or the first circumferential connector, and the axial connectors are unevenly distributed in the circumferential direction.

In an optional embodiment of the present invention, the material of the single-ring scaffold is a shape memory alloy.

In an alternative embodiment of the present invention, the single ring support comprises a peak, a valley and a wave rod connecting the peak and the valley, and the wave rod is tangent or not tangent to the peak/valley.

In an alternative embodiment of the present invention, the relative positions of the single-loop scaffolds of the vascular scaffold are the same or different.

In an optional embodiment of the present invention, the material of the connecting body is a shape memory alloy.

In an optional embodiment of the present invention, the connecting body is in a grid form.

In an optional embodiment of the present invention, the vascular stent further comprises a coating, and the coating is attached to the monocyclic stent or the linker.

In an optional embodiment of the present invention, the first circumferential connecting body is a ring shape, and the first circumferential connecting body is connected to the trough/peak of the single ring support by a winding manner.

In an optional embodiment of the utility model, the vascular stent further comprises a second circumferential connector circumferentially wrapped around the axial connector.

In an optional embodiment of the present invention, the first circumferential connector is a single-stranded metal wire or a multi-stranded twisted metal wire; the second circumferential connector is a single-stranded wire or a multi-stranded twisted wire.

In an optional embodiment of the present invention, the first circumferential connecting body includes a first knot, and the first knot is a knot wound around a peak or a trough of the single-ring stent.

In an alternative embodiment of the utility model, the axial connector is wound around the peak/trough and passes through the void of the first knot.

In an alternative embodiment of the present invention, the number of the first knots of one of the first circumferential connecting bodies is greater than or equal to half of the number of the peaks/valleys of one of the single-ring stents.

In an optional embodiment of the present invention, the first circumferential connecting body further includes a second knot, the second knot is formed by winding the first circumferential connecting body by itself and is located between adjacent wave crests or wave troughs of the single-ring support, and the axial connecting body is wound on the wave crest, the first knot, the second knot, the wave trough, and the first knot in an inserting manner.

In an alternative embodiment of the utility model, the axial connecting body is wound in the space of the second knot.

In an optional embodiment of the present invention, the axial connecting bodies include at least two, one of the axial connecting bodies is N-shaped, and the other axial connecting body is reverse N-shaped.

In an alternative embodiment of the utility model, the axial connectors are distributed over part of the circumference of the vessel support.

In an alternative embodiment of the present invention, the axial cross-sectional dimension of the metal wire of the connector is smaller than the axial cross-sectional dimension of the metal wire of the single loop stent.

In an optional embodiment of the present invention, a ratio of an axial cross-sectional dimension of the metal wire of the single-ring stent to an axial cross-sectional dimension of the metal wire of the connector is between 2 and 20.

The vascular stent has good bending performance, can obtain different support performance and flexibility performance in the circumferential direction according to requirements, and can better adapt to the bent vascular environment.

The vascular stent can keep the uniformity of the stent shape, and can obtain different supporting performance and compliance performance in the circumferential direction, and the different supporting performance and compliance performance of the whole stent in the circumferential direction can better adapt to the anatomical structure of the blood vessel.

The vascular stent has the advantages that the local covering membrane is matched with the good bending property of the stent, so that the vascular stent can be used for Debakey II type interventional therapy without branch vascular reconstruction and aortic arch involvement in the interlayer.

The intravascular stent has better fatigue resistance and can not damage the inner wall of a blood vessel.

The preparation method of the intravascular stent can easily change the overall mechanical property of the stent and produce more stents with different mechanical property specifications.

Drawings

Fig. 1 shows a schematic structural view of a vascular stent of the present invention.

Fig. 2 shows a perspective view of a single ring stent of the vascular stent of the present invention.

Fig. 3 shows a front view of a single ring stent of the vascular stent of the present invention.

Fig. 4 shows a structural schematic diagram of the single-ring stent of the vascular stent of the utility model, wherein the lengths of the wave bars are unequal.

Fig. 5a-5c show schematic views of three alternative forms of peaks or valleys of the inventive vascular stent.

Fig. 6 shows a schematic diagram of the relative positions of the single loop scaffolds of the vascular stent of the present invention.

Fig. 7 shows a perspective view of a connecting body of a vascular stent of the present invention.

Fig. 8 shows a front view of a connector of the vascular stent of the present invention.

Fig. 9 shows a winding schematic view of a connecting body of a vascular stent of the present invention.

Fig. 10a-10e show five alternative schematic views of the lattice morphology of the connectors of the vascular stent of the present invention.

Fig. 11 shows a structural diagram of a coating of the vascular stent of the present invention.

Fig. 12a and 12b show a schematic comparison of a prior art partial stent and a vascular stent of the present invention in a more curved configuration, respectively.

Fig. 13a and 13b show a comparison of the free side of a conventional partial stent and a vascular stent of the present invention after being stressed.

Fig. 14 shows a schematic view of the vascular stent of the present invention used for treating DeBakey type ii dissection.

Fig. 15 shows a partially enlarged view of the box area in fig. 14.

Fig. 16a-16c show schematic views of a prior art partial stent and a vascular stent of the present invention in comparison to each other after implantation in a blood vessel.

Description of the reference symbols

The stent 100, the non-covered section 100a, the covered section 100b, the single-ring stent 10, 10 ', the wave crest 101, the wave rod 102, the wave trough 103, the tube sleeve 104, the connecting body 20, 20', 21 circumferential connecting body, the first circumferential connecting body 211, the first knot 2111, the second knot 2112, the second circumferential connecting body 212, the axial connecting body 22, the first axial connecting body 22a, the second axial connecting body 22b, the covering film 30, the sheath tube 40, the fixing claw 50, the inner heart tube 60, the ascending aorta 701, the aortic arch 702, the descending aorta 703, the branch vessel 704, and the interlayer 705.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The utility model is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Please refer to fig. 1-16. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

For convenience of description, the terms appearing herein are to be construed:

small bending: a blood vessel, a stent, or the like is a quasi-circular tube, and when it is bent, the side having a smaller bending radius is a small bent side.

Large bending: blood vessels, stents, and the like are similar to a circular tube, and when they are bent, the side having a larger bending radius is a large-bent side.

Proximal end: the arterial blood vessels from the heart gradually branch into capillaries and then gradually merge into venous blood vessels back to the heart, wherein the end of any segment of the blood vessels close to the heart is called the proximal end.

Distal end: the arterial blood vessel from the heart gradually branches into capillaries and then gradually merges into venous blood vessels to return to the heart, wherein the end of any section of the blood vessel far away from the heart is called the far end.

Axial direction: blood vessels, interventional stents, and the like are all quasi-tubular, and if they are considered as cylinders, the cylindrical rotation axis is defined as the axial direction.

Radial: the radial direction is perpendicular to the axial direction, namely the radius or diameter direction of the end face circle of the cylinder, and the radial direction is perpendicular to the axial space.

Circumferential direction: "circumferential" or circumferential, which together with "axial" and "radial" constitute the three orthogonal directions of the cylindrical coordinates.

The present invention introduces an interventional vascular stent 100 (also referred to as a vascular stent), wherein fig. 1 shows a structural schematic diagram of the vascular stent 100 of the present invention. As shown in fig. 1, the vascular stent 100 is an assembly body formed by combining three components, i.e., a single-ring stent 10, a connector 20, and a coating film 30, through a certain process as a whole prosthesis for interventional therapy.

It should be noted that, in some embodiments, the vascular stent 100 may not include the coating 30, but may be an assembly directly formed by combining the single-ring stent 10 and the connecting body 20 through a certain process. The following description will be given taking as an example that the vascular stent 100 includes the monocyclic stent 10, the linker 20 and the coating 30.

As shown in fig. 1, in the present invention, the blood vessel stent 100 is composed of a multi-turn annular single-ring stent 10 and a multi-turn annular connector 20, the blood vessel stent is integrally in a tubular network structure, and the cover 30 is a layer of flexible thin film material attached to the single-ring stent 10 or the connector 20. The multi-ring annular single-ring stents 10 are sequentially arranged in parallel at intervals from the proximal end to the distal end of the intravascular stent 100, and a ring of connectors 20 is arranged between every two adjacent rings of single-ring stents 10, namely, the single-ring stents 10 and the connectors 20 are distributed at intervals along the axial direction of the intravascular stent 100. It should be noted that, in some embodiments, the connector 20 may not be disposed between two adjacent circles of the single-ring stent 10 connected by the covering membrane 30. The single ring stent 10 has a stronger bending resistance and a stronger supporting performance than the connectors, and when the vascular stent 100 is implanted to a lesion site, the single ring stent 10 can be anchored and supported at the lesion site to prevent the vascular stent 100 from being displaced. The connectors 20 have strong bending and flexibility properties of the single ring stent 10, and can be bent by means of a plurality of connectors 20 when the vascular stent 100 is delivered in a bent blood vessel and placed in the bent blood vessel. The coating 30 has high sealing performance, when the vascular stent 100 is implanted into a diseased part, the coating 30 can cover the diseased part and seal the diseased part, so that blood in the aorta is prevented from entering the tunica media of the blood vessel from the crack of the tunica intima, the tunica media of the blood vessel are prevented from being continuously separated, and the disease is relieved.

Fig. 2 shows a perspective view of the single ring support 10 of the present invention, and fig. 3 shows a front view of the single ring support 10 of the present invention. Referring to fig. 2 and 3, in the present invention, the single ring stent 10 is one of the components constituting the vascular stent 100, and the vascular stent 100 includes a plurality of single ring stents 10. Each single-ring stent 10 extends in the circumferential direction of the stent 100 to form a closed ring shape, and while extending in the circumferential direction, undulates in the axial direction of the stent 100, that is, the single-ring stent 10 is wavy in the axial direction thereof.

In the utility model, the single-ring support 10 is a ring which is formed by bending a metal wire with a circular cross section, performing heat treatment and shaping and is circular or approximately circular as a whole, and the single-ring support 10 is wavy in the axial direction while extending in the circumferential direction. The single ring stent 10 is made of a shape memory alloy, such as nickel titanium alloy (NiTi). The overall height H1 of the monocyclic scaffold 10 is in the range of 5-20mm, such as 5mm, 10mm, 15mm or 20 mm; the overall diameter D1 of the single ring scaffold 10 ranges from 10-50mm, such as 10mm, 20mm, 30mm, 40mm or 50 mm; the cross-sectional diameter d1 of the wire of the single loop stent 10 is in the range of 0.1-1mm, such as 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm or 1 mm.

In an alternative embodiment, the cross-section of the wire of the single loop stent 10 may also be square, trapezoid, or other suitable shapes, and when the cross-section of the wire of the single loop stent 10 is square, the diagonal dimension of the square is defined as d1, which is in the range of 0.1-1mm, such as 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm, or 1 mm.

In an alternative embodiment, the single ring stent 10 may also be made by laser cutting a metal tube, expanding the tube by heat treatment, and shaping the tube. In an alternative embodiment, the single ring support 10 can also be fabricated in one step from 3D metal printing.

Referring to fig. 2 and 3, in the present invention, the single ring stent 10 includes peaks 101, valleys 103 and wave rods 102 connecting the peaks 101 and the valleys 103, one peak 101 and two adjacent wave rods 102 form a wave, and the peaks 101 and the valleys 103 are relative, so that the single ring stent 10 is inverted in the axial direction, the peaks are changed into the valleys, and the valleys are changed into the peaks. The number of waves of a single loop stent 10 is not fixed, and is set according to the value of the overall height H1 of the single loop stent 10 and the overall diameter D1 of the single loop stent 10 according to the physiological anatomical structure of the aorta. As an example, the wave number of one single-loop scaffold 10 is between 3 and 12, wherein the case where the wave number of the single-loop scaffold 10 is 6 is shown in fig. 2.

In the present invention, the radius R of the transition fillet between the peak 101 or the valley 103 is in the range of 0-5mm, such as 0mm (corresponding to the case where two adjacent wave bars 102 are directly connected without fillet), 1mm, 2mm, 3mm, 4mm or 5 mm. The R values of the single-ring scaffolds 10 are not necessarily the same, i.e., the sizes of the peaks 101 or the troughs 103 of the same single-ring scaffold 10 may be the same or different. The magnitude of each R value should be set according to the requirements of the later-stage crimping function of the stent 100. As an example, in fig. 3, it is shown that several peaks 101 or valleys 103 of the same single loop scaffold 10 are the same size.

In the present invention, the field angle of the peak 101 (i.e. the included angle α between two adjacent wave bars 102) is in the range of 10 ° -70 °, such as 10 °, 20 °, 30 °, 40 °, 50 °, 60 °, or 70 °, and the field angles α of several peaks 101 in the same single-ring stent 10 may be the same or different, and the magnitude of each α value should be set according to the requirements of the functions of the vascular stent 100 such as post-crimping.

Fig. 2 and 3 show the situation that all wave bars 102 of the single ring stent 10 are tangent to the adjacent wave crests 101 or wave troughs 103, and all alpha values are at the same acute angle (of course, an obtuse angle is also possible). It is understood that the wave rod 102 and the wave peak 101 or the wave trough 103 can also adopt one of the wave forms shown in fig. 5a-5c, wherein in fig. 5a, the wave rod 102 and the wave peak 101 or the wave trough 103 are not tangent, and α is an acute angle, and the wave peak 101 or the wave trough 103 presents a major arc form; in fig. 5b, the wave rod 102 is not tangent to the wave crest 101 or the wave trough 103, and α is an obtuse angle, and the wave crest 101 or the wave trough 103 presents a minor arc shape; in fig. 5c, the peak 101 or the valley 103 may be "M" or "W" shaped, etc.

Referring to fig. 2-4, in the present invention, the wave bar 102 is a straight bar connecting the wave crests 101 and the wave troughs 103. The length L1 of the wave bar 102 ranges from 1-30mm, and the length L1 of the wave bar 102 ranges from 1-30mm, such as 1mm, 5mm, 10mm, 15mm, 20mm, 25mm, or 30 mm. The length L1 of the wave bars 102 may be the same or different in the same single ring stent 10. As an example, the situation where the lengths L1 of all wave bars 102 of each single ring rack 10 are equal is shown in fig. 3. As an example, fig. 4 shows a schematic structural diagram of the single-ring stent 10 when the lengths of the wave bars 102 are unequal, and when the lengths L1 of the wave bars 102 are unequal, the waves in the single-ring stent 10 are in different sizes, and the waves with different sizes have different bending properties, which can better adapt to a bent blood vessel. In addition to the straight rod, the wave rod 102 may also be an "S" shaped rod, a "Z" shaped rod, or the like.

Referring to fig. 2, in the present invention, the single ring stent 10 further comprises a tube sleeve 104, and the tube sleeve 104 may be a thin-walled metal sleeve with an inner diameter slightly larger than the cross-sectional diameter d1 of the metal wire of the single ring stent 10. Fig. 2 shows a single loop stent 10 comprising 2 sleeves 104, one sleeve 104 serving to join the ends of the wires making up the single loop stent 10, with one wire being an end-to-end loop by means of clamping or welding. Another sleeve 104 is threaded over the wave bar 102, the tip of the connector 20 is embedded in the sleeve 104, and the sleeve 104 is clamped so that the sleeve 104 and the tip are secured to the wave bar 102. The sleeve 104 is made of a suitable material such as stainless steel or NiTi. It will be appreciated that only one 104 sleeve can be used for connecting the ends of the single loop stent 10 wires, and the ends of the connectors 20 can be trimmed without being embedded in the sleeve 104.

It will be appreciated that the sleeve 104 need not be used when the single ring stent 10 is manufactured for cutting or metal printing.

As shown in fig. 6, the relative positions of the plurality of single-loop stents 10 in the vascular stent 100 may be the same or different. In the lower oval area in fig. 6, the peaks 101 of two adjacent single-ring scaffolds 10 are arranged in a staggered manner, the peak 101 of one single-ring scaffold 10 is located between the two peaks 101 of another single-ring scaffold 10, for example, two adjacent single-ring scaffolds 10, and the peak 101 of one single-ring scaffold 10 can be vertically opposite to the valley 103 of another single-ring scaffold 10 in the axial direction; in fig. 6, the upper oval region, two adjacent single-ring stents 10, the peak 101 of one single-ring stent 10 may be axially and obliquely opposite to the valley 103 of another single-ring stent 10, that is, the peak 101 of one single-ring stent 10 is located between the two valleys 103 of another single-ring stent 10, for example, the peaks 101 of two adjacent single-ring stents 10 are aligned.

Fig. 7 shows a schematic perspective view of the connector 20 of the present invention, fig. 8 shows a schematic front plan view of the connector 20 of the present invention, and fig. 9 shows a schematic winding view of the connector of the vascular stent of the present invention.

Referring to fig. 7 to 9, in the present invention, the connecting body 20 is composed of a plurality of flexible rope-like bodies wound around a plurality of single-ring brackets 10 to connect adjacent single-ring brackets 10. Meanwhile, a plurality of rope-like flexible bodies can be alternately woven to form a connector 20. The flexible body such as a wire is made of a shape memory alloy, such as nickel-titanium alloy (NiTi), and the connecting body 20 is made of a metal wire. The axial cross-sectional dimension d2 of the wire used for the linker 20 is smaller than the axial cross-sectional dimension d1 of the wire used for the single loop stent 10, d1: d2 is 2-20, such as 2, 5, 8, 11, 14, 17, 20. The connecting body 20 comprises a circumferential connecting body 21 and an axial connecting body 22.

Referring to fig. 7-9, in the present invention, the circumferential connector 21 includes a first circumferential connector 211 and a second circumferential connector 212. The first circumferential connection body 211 is a metal wire wound in the circumferential direction to connect the troughs 103 or the crests 101 of the single ring stent 10, and is formed into a circular or approximately circular ring in the same form as the single ring stent 10 in the circumferential direction by bending, winding and heat treatment of the metal wire. The first circumferential connector 211 may be a single-stranded metal wire or a multi-stranded twisted metal wire. The first circumferential connecting body 21 includes a first knot 2111 formed by winding the peak 101 or the valley 103 and a second knot 2112 wound on itself and located between the adjacent peaks 101 or valleys 103. The first knot 2111 can be in any suitable knot form, such as a prussian knot, a single knot, a splayed knot, a continuous knot or a direct winding knot; the second knot 2112 may be any suitable knot form, such as a prussian knot, a single knot, a figure eight knot, a continuous knot, or a direct loop.

The number of the first knots 2111 of each first circumferential connecting body 21 is not limited, nor is it limited that they must be evenly distributed circumferentially, i.e. some of the peaks 101 or valleys 103 may not have first knots 2111 tied. The number of the first knots 2111 is at most the same as the number of the peaks 101 or the valleys 103, but is at least not less than half of the number of the peaks 101 or the valleys 103 of each first circumferential connecting body 21.

The number of the second knots 2112 of the first circumferential connecting body 21 is not limited, that is, there may be no knot wound around itself between the adjacent peaks 101 or valleys 103, and there may be a plurality of knots. The number of second knots 2112 should be adapted to the desired form of the axial connection body 22.

The axial connecting body 22 is threaded around the crest 101 and the first and second knots 2111, 2112, the trough 103 and the first knot 2111. The axial connecting body 22 is formed by bending, winding and heat treatment setting of a metal wire, and the shape of the axial connecting body 22 in the circumferential direction is a circular or approximately circular ring or a semicircular or approximately semicircular arc shape matched with the single ring stent 10. When the axial connection body 22 is wound on the peak 101 or the valley 103, it needs to pass through the gap of the first knot 2111, so as to ensure that the axial connection body 22 binds itself, the first knot 2111 and the peak 101 or the valley 103 together, so as to limit the sliding of the winding point of the first knot 2111 and the axial connection body 22 on the monocyclic support 10. The axial connector 22 needs to be wound in the space of the second knot 2112 to limit the sliding of the axial connector 22 on the first circumferential connector 211.

As shown in fig. 1 and 7, in the present invention, the axial connection bodies 22 are arranged in a non-uniform arrangement in the circumferential direction, the axial connection bodies 22 are disposed in a partial region in the axial direction, and the axial connection bodies 22 are not disposed in other regions,

in other words, adjacent single ring scaffolds 10 may be axially connected only in a portion of the regions, while not being axially connected in other regions, and the portions of the single ring scaffold that are not axially connected may be in a free state in the axial direction.

It is understood that, in other embodiments, the manner that the axial connection bodies 22 are unevenly distributed in the circumferential direction may also mean that the density of the axial connection bodies 22 in the circumferential direction is not uniform, a part of the axial connection bodies are densely distributed, and a part of the axial connection bodies are sparsely distributed. It should be noted that, in the present invention, when the peak 101 or the valley 103 is in the form shown in fig. 5a to 5c, the first knot 2111 can be better resisted from sliding on the single loop stent 10.

In the present invention, the axial connecting body 22 may be in the form of a prussian knot, a single knot, a splayed knot, a hitch knot, or the like at the first knot 2111 or the second knot 2112, in addition to the direct winding method shown in fig. 9. For example: when the first knot 2111 is a prussian knot, the axial connector 22 may be tied to another opposing prussian knot to form interpenetrating double prussian knots. When the second knot 2112 is a single knot, the axial connector 22 may be tied to a single knot to form a double knot.

In the present invention, the number and uniformity of winding points of the axial connection bodies 22 on the crests 101, troughs 103 or the circumferential connection bodies 21 are not fixed, that is, the axial connection bodies may not be wound on a part of the crests 101, the troughs 103 or a certain segment of the circumferential connection bodies 21.

As shown in fig. 9, the connecting body 20 includes two axial connecting bodies 22a and 22b, one of the axial connecting bodies 22b is a "N" type with a height offset, and the other of the axial connecting bodies 22a is an inverted "N" type with a height offset.

Fig. 9 shows the case where the first knot 2111 is a prussian knot and the second knot 2112 is a single knot, for example, a first knot 2111 is provided on each peak 101 or trough 103, a second knot 2112 is provided between each adjacent peak 101 or trough 103, and the axial connection 22 is wound once on each first and second knot 2111, 2112.

As shown in fig. 9, in the present invention, the second circumferential connecting body 212 is located between two adjacent first circumferential connecting bodies 211, and can be connected to the axial connecting body 22 in a winding manner in the circumferential direction. When the axial connection body 22 is provided in a partial region in the circumferential direction, the second circumferential connection body 212 is also arranged only in the region of the corresponding axial connection body 22.

In fig. 9, the connecting body 20 comprises three circumferential connecting bodies 21, namely two first circumferential connecting bodies 211 and one second circumferential connecting body 212, wherein one first circumferential connecting body 211 is wound on the wave crest 101 of one side of the single-ring support 10, and the other first circumferential connecting body 211 is wound on the wave trough 103 of the other side of the single-ring support 10; a second circumferential connecting body 212, which is located in the axial middle plane of the axial connecting body 22, is wound around the axial connecting body 22, and optionally is also tied to the axial connecting body 22 in a suitable manner.

In the present invention, the number and form of the axial connecting bodies 22 between two adjacent monocyclic stents 10 are not limited to those shown in fig. 9. The number and shape of the axial connectors 22 should be matched to the desired support and compliance characteristics of the stent 100. As an example, the number of the circumferential connecting bodies 21 between two adjacent single ring brackets 10 is 2 to 5, that is, besides two first circumferential connecting bodies 211 wound around the opposite peaks 101 and valleys 103 of two adjacent single ring brackets 10, 0 to 3 second circumferential connecting bodies 212 are distributed in the axial direction of the axial connecting body 22, that is, in some embodiments, the second circumferential connecting bodies 212 may not be provided. The number of the axial connectors 22 between two adjacent single-ring brackets 10 can be 1-3, and the shape is N type, reverse N type or Z type.

As shown in fig. 9, the connector 20 is a grid shape composed of several triangles with different orientations. It will be appreciated that the final grid configuration of the connectors 20 may also be a plurality of grid configurations as shown in FIGS. 10a-10e, depending on the arrangement of the circumferential connectors 21 and the axial connectors 22 described above. The grid pattern of the same connector 20 may be single or different in sections. The lattice patterns of the connectors 20 on the same stent 100 may be the same or different.

The structural design of the connecting body 20 of the utility model, the circumferential connecting body 21 and the axial connecting body 22 form mutual limit to prevent the node from sliding on the wave rod of the bracket.

The connector of the existing naked stent only can take the vertex of the stent ring of the single-ring stent as the winding position of the node; in the structural design of the connecting body 20 of the present invention, the circumferential connecting body 21 can be used as a winding point of the axial connecting body at any position within 360 ° in the circumferential direction, and the axial connecting body 22 has more nodes winding positions, so that the axial connecting body 22 can be only intensively arranged at one side of the vascular stent and is separated from the vascular stent at the other side in the axial direction.

As shown in fig. 1, in the present invention, the coating 30 is one of the components constituting the vascular stent 100, and the vascular stent 100 may contain several coatings 30. The cover film 30 is a layer of flexible thin film material attached to the monocyclic scaffold 10 or the linker 20. The material of the cover film 30 may be PET (polyester fiber ) or EPTFE (polytetrafluoroethylene), for example. The coating 30 is attached to at least one single-ring scaffold 10 or one linker 20, and at most to all single-ring scaffolds 10 and linkers 20.

As shown in FIG. 11, the position of the stent graft 30 is optional and can be attached to different single-loop stents 10 or connectors 20 of the vascular stent 100 as desired. The coating 30 can be attached to the outside, inside, or both the outside and inside of the monocyclic scaffold 10 or the linker 20. The cover film 30 can be attached to the single loop stent 10 or the connector 20 by any suitable means such as adhesive (e.g., heat staking), sewing, etc.

The advantageous effects of the stent 100 of the present invention will be explained by comparison with the existing stent.

1. The vascular stent 100 of the utility model has good bending performance, can obtain different support performance and compliance performance in the circumferential direction according to the requirement, and can better adapt to the bending vascular environment.

As shown in fig. 12a, in the existing partially bare stent, the peaks and troughs of two adjacent single-ring stents are connected by silk threads, so that the bending performance is poor, the supporting performance and the flexibility of the whole stent in the circumferential direction are uniform, and the stent cannot be well adapted to the bent vascular environment. When the support is bent greatly, the wave rods of the adjacent single-ring supports at the large bend of the support are excessively pulled by the silk threads, and the support is excessively bent towards the central axis at the small bend, so that the bent section is distorted.

As shown in fig. 12b, the vascular stent 100 of the present invention has good bending performance, and the connecting body 20 can be designed in sections as required to obtain different support performance and compliance performance in the circumferential direction, so as to better adapt to the bending vascular environment. The part without the axial connecting body 22 can be used as the large bending side of the bracket bending, the bracket part at the large bending is in a free state in the axial direction, and the parts of the bracket at the small bending are only mutually overlapped at the moment, so that the bracket cannot be excessively bent towards the central axis.

2. The vascular stent 100 of the utility model not only can keep the uniformity of the stent shape, but also can obtain different support performance and compliance performance in the circumferential direction, and the different support performance and compliance performance of the whole stent in the circumferential direction can better adapt to the anatomical structure of the blood vessel.

As shown in fig. 13a, in the conventional partial stent, since there is no circumferential connecting body as a winding point of the axial connecting body, the axial connecting body can only use the wave crest and the wave trough of each ring stent as a connection point, and in order to ensure the circumferential uniformity of the whole stent, the axial connecting body must be uniformly distributed on the single ring stent in the circumferential direction, which also results in uniform support and flexibility of the whole stent in the circumferential direction. If part of the axial connectors are removed, the free waves of the single-ring stent may be deformed axially by external force. For example, when an interventional operation is performed, the entire stent may not be properly placed, and the position of the stent needs to be adjusted.

As shown in fig. 13b, in the blood vessel stent 100 of the present invention, since the circumferential connecting body 21 is used as the winding point of the axial connecting body 22, the axial connecting body 22 can be freely arranged in the circumferential direction according to the design requirement, so as to obtain different support performance and compliance performance in the circumferential direction. Meanwhile, due to the limit of the circumferential connecting body 21, the single-ring support 10 has no absolute free wave and cannot generate axial deformation. When the vascular stent 100 of the present invention is placed in the ascending aorta, the proximal end of the ascending aorta will contract more than the distal end along with the beating of the heart, so the proximal end supporting performance of the vascular stent 100 can be reduced by the design and adjustment of the circumferential connecting body 21 and the axial connecting body 22 of the present invention, without changing the mechanical properties of the rest of the vascular stent 100, so as to better adapt to the proximal systolic relaxation of the ascending aorta.

3. As shown in fig. 14 and 15, the local covering film of the intravascular stent of the present invention is matched with the excellent bending property of the stent, so that the intravascular stent 100 of the present invention can be used for debarkey type ii interventional therapy without branch vessel reconstruction and aortic arch involvement in dissection.

At present, the number of special blood vessel stents for treating the Debakey II type is less, especially for the Debakey II type which does not need to reconstruct a branch blood vessel 704 and does not involve the aortic arch 702 by a dissection 705. Since the ascending aorta 701 is short and close to the heart, in order to prevent the detachment of the stent inserted into the portion, the stent needs to have a length sufficient to span the aortic arch 702 to complete anchoring. If the traditional covered stent is used for interventional therapy, the polymer membrane blocks the blood supply of the branch vessel 704 at the aortic arch 702, so that the membrane 30 needs to be perforated, and the precise matching of the perforated hole and the branch vessel 704 is completed, which greatly increases the difficulty of the operation.

As shown in fig. 14 and 15, the stent 100 of the present invention has a covering membrane 30 attached to the proximal end thereof, which can close the laceration of the dissecting 705 on the ascending aorta 701, so as to achieve the purpose of treating Debakey type ii dissecting. The stent 100 of the present invention spans the uncoated segment 100a of the aortic arch 702 not only to allow free flow of blood from the thoracic aortic vessel to the branch vessels 704, but also to prevent the dissection of the dissection 705 from expanding toward the aortic arch 702. Meanwhile, the vessel stent 100 of the present invention can design the appropriate size of the single ring stent 10 and the size of the connecting body 20 according to the interval of the branch vessel 704 of the aortic arch 702, so that the adjacent single ring stents 10 are clamped at both sides of the branch point of the branch vessel 704, thereby ensuring that the branch point of the branch vessel 704 is completely free from the interference of the single ring stent 10 or the connecting body 20, and greatly ensuring the smooth blood circulation.

The blood vessel stent 100 of the present invention can also be precisely positioned, if a small branch blood vessel 704 grows in the blood vessel region covered by the axial connecting body 22, the axial connecting body 22 can be densely arranged at the part far away from the branch of the branch blood vessel 704, and the axial connecting body is sparsely arranged at the branch of the branch blood vessel 704, so as to reduce the blood flow interference to the branch blood vessel and ensure the smooth blood flow.

In addition, the covering film 30 attached to the distal end of the blood vessel stent 100 can relieve the pressure of the free vertex of the end of the stent on the inner wall of the blood vessel and reduce the risk of intimal rupture.

4. The inventive stent 100 has better fatigue resistance without causing damage to the inner wall of the blood vessel.

In the prior art stent shown in fig. 16a, since the circumferential connecting bodies are not used as winding points of the axial connecting bodies, the axial connecting bodies are uniformly distributed on the single-ring stent in the circumferential direction, and the support and flexibility of the whole stent in the circumferential direction are uniform. When the integral bracket is placed in a bent blood vessel, the inner integral bracket is in a compressed state, and the outer integral bracket is in a stretched state. Due to the fact that the outer axial connecting body pulls the transition of the outer side of the single-ring support, the outer wave of the single-ring support is deformed like an inner buckle under the pulling force (see the area shown by a circle in fig. 16 a). According to the basic knowledge of material mechanics, the fatigue performance of the single-ring bracket and the connecting body in the state is weakened. In the utility model, the connecting body is designed in different sections, so that the problems can be better solved. Namely, an axial connector is arranged at the position without transition traction at the inner side to connect a plurality of single-ring brackets, so that the continuity of the whole bracket is ensured; the design of the axial connecting body is cancelled at the position where the transitional traction is generated outside so as to ensure the flexibility of the outer side of the whole stent, thereby ensuring that the vascular stent 100 has better fatigue resistance.

The existing stent shown in fig. 16b has no circumferential connecting body as a winding point of the axial connecting body, and a part of the axial connecting body located on the outer side is removed, when the whole stent is placed in a bent blood vessel, the whole stent on the inner side is in a compressed state, the outer wave of the single-ring stent is completely in a free state, the outer wave of the single-ring stent can generate an outward warped state (see the area indicated by the circle in fig. 16 b), at this time, the outward warped outer wave can cause damage to the inner wall of the blood vessel, and particularly, the inner cortex of the blood vessel in a diseased state is very easy to be scratched.

As shown in fig. 16c, the stent 100 of the present invention has the axial connectors 22 in the inner region and no axial connectors 22 in the outer region, i.e., the outer waves of the single loop stent 10 are not excessively pulled by the connectors 20. Due to the limit of the circumferential connecting body 21, the outer wave can not be completely dissociated and upwarps, so that the fatigue performance of the whole stent is not influenced, and the inner wall of the blood vessel is not damaged.

In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the utility model. One skilled in the relevant art will recognize, however, that an embodiment of the utility model can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of embodiments of the utility model.

It will also be appreciated that one or more of the elements shown in the figures can also be implemented in a more separated or integrated manner, or even removed for inoperability in some circumstances or provided for usefulness in accordance with a particular application.

Additionally, any reference arrows in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise expressly specified. Further, as used herein, the term "or" is generally intended to mean "and/or" unless otherwise indicated. Combinations of components or steps will also be considered as being noted where terminology is foreseen as rendering the ability to separate or combine is unclear.

The above description of illustrated embodiments of the utility model, including what is described in the abstract of the specification, is not intended to be exhaustive or to limit the utility model to the precise forms disclosed herein. While specific embodiments of, and examples for, the utility model are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the present invention and are to be included within the spirit and scope of the present invention.

The systems and methods have been described herein in general terms as the details aid in understanding the utility model. Furthermore, various specific details have been given to provide a general understanding of the embodiments of the utility model. One skilled in the relevant art will recognize, however, that an embodiment of the utility model can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, and/or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the utility model.

Thus, although the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of the utility model will be employed without a corresponding use of other features without departing from the scope and spirit of the utility model as set forth. Thus, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the utility model not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the utility model will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the utility model is to be determined solely by the appended claims.

Claims (19)

1. A vascular stent, comprising:

the single-ring supports are arranged at intervals along the axial direction, and the single-ring supports are wavy along the axial direction while extending in the circumferential direction;

the adjacent two single-ring brackets are connected through the connectors;

wherein the connectors comprise two first circumferential connectors and at least one axial connector;

one first circumferential connector is circumferentially connected with a wave crest of one single-ring bracket, and the other first circumferential connector is circumferentially connected with a wave trough of the other single-ring bracket;

the axial connectors are axially connected with wave crests or wave troughs of two adjacent single-ring supports or the first circumferential connector, and the axial connectors are unevenly distributed in the circumferential direction.

2. The vascular stent of claim 1, wherein the material of the single loop stent is a shape memory alloy.

3. The vascular stent of claim 1, wherein the single loop stent comprises peaks, valleys and wave bars connecting the peaks and valleys, the wave bars being tangent or non-tangent to the peaks/valleys.

4. The vascular stent of claim 1, wherein the relative position of each of the single-loop stents of the vascular stent is the same or different.

5. The vascular stent of claim 1, wherein the material of the connector is a shape memory alloy.

6. The vascular stent of claim 1, wherein the connectors are in a grid configuration.

7. The vascular stent of claim 1, further comprising a coating attached to the single-loop stent or the linker.

8. The vessel support according to claim 1, wherein the first circumferential connecting body is in a ring shape, and the first circumferential connecting body is connected with the wave trough/wave crest of the single ring support by a winding manner.

9. The vascular stent of claim 1, further comprising a second circumferential connector that circumferentially wraps around the axial connector.

10. The vascular stent of claim 9, wherein the first circumferential connector is a single strand of wire or a multi-strand twisted wire; the second circumferential connector is a single-stranded wire or a multi-stranded twisted wire.

11. The vascular stent of claim 1, wherein the first circumferential connector comprises a first knot, the first knot being a knot wrapped around a crest or trough of the single loop stent.

12. A vascular stent as in claim 11, wherein the axial connectors are wrapped around the peaks/valleys and pass through the interstices of the first knot.

13. The vascular stent of claim 11, wherein the number of the first knots of one of the first circumferential connectors is greater than or equal to half of the number of peaks/valleys of one of the single loop stents.

14. The vessel stent as recited in claim 11, wherein the first circumferential connecting body further comprises a second knot formed by winding the first circumferential connecting body by itself and located between adjacent peaks or valleys of the single ring stent, and the axial connecting body is alternately wound on the peaks, the first knot, the second knot, the valleys and the first knot.

15. The vascular stent of claim 14, wherein the axial connector wraps around the interstices of the second knot.

16. The vascular stent of claim 1, wherein the axial connectors comprise at least two, one of the axial connectors being "N" shaped and the other axial connector being of the opposite "N" shape.

17. The vascular stent of claim 1, wherein the axial connectors are distributed over a portion of the circumference of the vascular stent.

18. The vascular stent of claim 1, wherein the axial cross-sectional dimension of the wires of the connectors is smaller than the axial cross-sectional dimension of the wires of the single loop stent.

19. The vessel stent of claim 18, wherein the ratio of the axial cross-sectional dimension of the metal wire of the single-ring stent to the axial cross-sectional dimension of the metal wire of the connector is between 2 and 20.

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