Disclosure of Invention
The present invention aims to provide a vascular stent, which alleviates the above technical problems existing in the prior art.
In order to achieve the above purpose, the embodiment of the present invention adopts the following technical scheme:
The embodiment of the invention provides a vascular stent, which comprises a proximal stent, a middle stent and a distal stent which are sequentially arranged in the axial direction, wherein the middle stent is an elastic stent which can be radially compressed and has rebound characteristics after being released, and the vascular stent comprises: the proximal stent and/or the distal stent is a ring-shaped bare stent, and: the annular bare support comprises a plurality of arc-shaped sheet units which are sequentially arranged in a head-to-tail lamination mode along the circumferential direction, and the head-to-tail lamination mode is as follows: in the circumferential clockwise or anticlockwise direction, the head end of the next arc-shaped sheet unit is laminated on the radial inner side of the tail end of the previous arc-shaped sheet unit, and each two adjacent arc-shaped sheet units are connected together through a circumferential constraint limiting structure, and the circumferential constraint limiting structure is used for limiting the relative sliding distance of the two adjacent arc-shaped sheet units along the circumferential direction of the annular bare support so as not to slide each other; each arc-shaped sheet unit is connected with at least two points of the middle section support.
In particular, in embodiments of the present invention, "the proximal stent and/or the distal stent are" in the form of a ring-shaped bare stent "and/or" includes any of the following meanings: (1) only the proximal stent is the annular bare stent, (2) only the distal stent is the annular bare stent, and (3) both the proximal stent and the distal stent are the annular bare stent.
In the embodiment of the present invention, preferably, the circumferential constraint and limit structure includes a limit slot and a limit protrusion respectively provided on each of the arcuate sheet units; the limiting long groove extends along the circumferential direction of the annular bare bracket, and two ends of the limiting long groove in the length direction are closed; in each two adjacent arc-shaped sheet units in the circumferential direction of the annular bare support, the limiting protrusion of one arc-shaped sheet unit is limited in the limiting long groove of the other arc-shaped sheet unit in a sliding mode.
Further preferably, the limiting long groove is communicated with the radial outer surface of the arc-shaped sheet unit, and the limiting protrusion is arranged on the radial inner surface of the arc-shaped sheet unit in a protruding mode. Still further preferably, the limiting slot is a through slot radially penetrating through the corresponding arcuate sheet unit, each limiting protrusion penetrates through the corresponding limiting slot, and a limiting end for preventing the limiting protrusion from separating from the limiting slot is arranged at one end of each limiting protrusion, which is away from the arcuate sheet unit.
In addition, preferably, in each two adjacent arc-shaped sheet units in the circumferential direction of the annular bare support, the axial height of the limiting long groove of one arc-shaped sheet unit is different from the axial height of the limiting long groove of the other arc-shaped sheet unit on the annular bare support. Further preferably, the axial heights of the limiting long grooves of any two arc-shaped sheet units in the circumferential direction of the annular bare bracket are different.
In addition, in the embodiment of the present invention, preferably, the annular bare support further includes a unidirectional limiting structure, and when the annular bare support transitions from a radially contracted state to a freely released state, two adjacent arcuate sheet units slide relatively in one direction and in opposite directions along the circumferential direction of the annular bare support under the limitation of the unidirectional limiting structure.
Further preferably, the unidirectional limiting structure comprises an abutting part arranged on each arc-shaped sheet unit and a plurality of rows of ratchet structures arranged on each arc-shaped sheet unit; the plurality of rows of ratchet structures are arranged in parallel along the circumferential direction of the annular bare bracket and incline towards the end direction of the adjacent arc-shaped sheet-shaped units; under the static structure, every adjacent two in the annular naked support circumference in the arc lamellar unit, the butt portion of arc lamellar unit butt in another the ratchet structure of arc lamellar unit is listed as to prevent adjacent two the arc lamellar unit is followed the circumference of annular naked support slides in opposite directions.
Further preferably, the ratchet structure is provided on an inner side surface of the arcuate sheet-like unit, and the abutment portion is an end surface of the arcuate sheet-like unit laminated on a radially inner side surface of each adjacent two of the arcuate sheet-like units in the circumferential direction of the annular bare stent.
Furthermore, in an embodiment of the present invention, it is preferable that each of the arcuate sheet-like units is made of a super elastic material; and/or the middle section support is a covered support, and/or the middle section support (2) is made of super-elastic materials. The arc-shaped sheet units are made of super-elastic materials, the middle section support is a covered support and the middle section support (2) is made of super-elastic materials, and the vascular support is designed simultaneously or selectively.
In the implantation process of the vascular stent provided in the present embodiment:
(1) During conveying, the vascular stent is radially contracted, and the deformation of the annular bare stent at the proximal end and the distal end of the vascular stent is as follows: adjacent arc-shaped sheet units slide along the circumferential direction of the annular bare stent in opposite directions so as to enable the annular bare stent to shrink radially and form a shape similar to a cylinder after shrinkage, and the adjacent two arc-shaped sheet units are restrained by a circumferential restraining and limiting structure and are not slipped (the end lamination state is kept), so that the vascular stent is compressed into a conveyor outer sheath tube with the minimum diameter;
(2) The vascular stent is delivered to the position for release, because each arc-shaped sheet unit of the annular bare stent at the end part of the vascular stent is connected with at least two points of the middle-section stent, the middle-section stent is sprung and opened, each arc-shaped sheet unit is carried to be sprung and opened in a scattered way, the adjacent arc-shaped sheet units reversely slide along the circumferential direction of the annular bare stent, and the adjacent two arc-shaped sheet units are restrained and limited by the circumferential restraint limiting structure to not slide (keep the end part laminated state) each other (the arc-shaped sheet units of the annular bare stent at the end part of the vascular stent are all connected with at least two points of the middle-section stent, and certain path restraint can be carried out on the scattered and opened or contracted and gathered of each arc-shaped sheet unit, so that the arc-shaped sheet units are prevented from being scattered or contracted irregularly).
In the annular bare stent at the end part of the vascular stent, the adjacent arc-shaped sheet units have the movement trend of mutually dispersing and bouncing open due to the design of arc streamline surfaces, and the radial outer surfaces of the arc-shaped sheet units are attached to the vascular intima without the help of a tectorial membrane by the elastic pulling force of the middle section stent. Compared with a diamond ring or M-shaped ring stent connected with a tectorial membrane in the prior art, the end structure of the vascular stent after being opened is characterized in that:
(1) The end part structure of the vascular stent in the embodiment is an annular bare stent, has no tectorial membrane structure, and does not influence the climbing attachment of endothelial cells on the radial outer surface of the bare stent, so that the positioning effect in the blood vessel is better, and the vascular stent is not easy to shift for a long time on the basis of not shifting for a short time;
(2) The annular bare stent at the end part of the vascular stent is of a monolithic structure formed by combining a plurality of arc-shaped sheet units, and the end part of the annular bare stent is free of large grids or meshes, so that vascular endothelial cells can be prevented from proliferating inwards through meshes at the end part of the bare stent to block blood vessels;
(3) The annular bare stent at the end part of the vascular stent in the embodiment is of a monolithic structure formed by combining a plurality of arc-shaped sheet units, has no sharp part, has small stimulation to the vascular intima and avoids damaging the vascular intima.
Therefore, the vascular stent provided by the embodiment relieves the problems that the peripheral vascular stent of the existing structure type cannot comprehensively coordinate high flexibility, high radial supporting force at the far end and the near end, reduces the irritation to the intima of the blood vessel and prevents the displacement function after long-term use, and meanwhile, the flexibility of the vascular stent is not influenced.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that: like reference numerals and letters designate like items in the drawings, and thus once an item is defined in one drawing, no further definition or explanation thereof is necessary in the subsequent drawings.
In the description of the present invention, it should be noted that, unless explicitly stated and limited otherwise, the terms "provided," "configured," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
The terms "proximal," "distal," "inner," "outer," and the like refer to an orientation or positional relationship based on that shown in the drawings, or that is conventionally laid out when the inventive product is used, merely to facilitate description of the invention and to simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention. In particular, the term "proximal" refers to the inflow end in the direction of blood flow after implantation of the stent into a patient's vessel, "distal" refers to the other end (outflow end in the direction of blood flow) opposite to "proximal", axial "refers to the direction of the stent parallel to the longitudinal central axis," radial "refers to the direction perpendicular or substantially perpendicular to the axial direction, and" circumferential "refers to the direction around the axial direction.
Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.
The present embodiment provides a vascular stent, referring to fig. 1 to 7, comprising a proximal stent 1, a middle stent 2 and a distal stent 3 arranged in this order in the axial direction, the middle stent 2 being an elastic stent having a rebound property after being released and being radially compressible, wherein: the proximal stent 1 and/or the distal stent 3 are annular bare stents, and: the annular bare support includes a plurality of arc sheet units 100 that range upon range of arrangement in proper order along circumference, and this range upon range of arrangement mode of head and tail is: in the circumferential clockwise or counterclockwise direction, in each two adjacent arc-shaped sheet units 100, the head end of the next arc-shaped sheet unit 100 is laminated on the radial inner side of the tail end of the previous arc-shaped sheet unit 100, and each two adjacent arc-shaped sheet units 100 are connected together through a circumferential constraint limiting structure, and the circumferential constraint limiting structure limits the relative sliding distance of the two adjacent arc-shaped sheet units 100 along the circumferential direction of the annular bare support so that the two arc-shaped sheet units 100 do not slip off each other; each arcuate sheet unit 100 is connected to the intermediate support 2 at least at two points.
In the implantation process of the vascular stent provided in the present embodiment:
(1) During conveying, the vascular stent is radially contracted, and the deformation of the annular bare stent at the proximal end and the distal end of the vascular stent is as follows: adjacent arcuate sheet units 100 slide in the circumferential direction of the annular bare stent in opposite directions to radially shrink the annular bare stent, and after shrinking, the annular bare stent takes the form of an approximate cylinder shown in fig. 6 and 7, and the adjacent two arcuate sheet units 100 are restrained from slipping off each other (keeping an end laminated state) by a circumferential restraining and limiting structure, so that the vascular stent is compressed into a conveyor outer sheath tube with a minimum diameter;
(2) The vascular stent is delivered to the target position for release, because each arc-shaped sheet unit 100 of the annular bare stent at the end part of the vascular stent is connected with at least two points of the middle-section stent 2, the middle-section stent 2 is an elastic stent, thus, the middle-section stent 2 can be sprung and opened by carrying each arc-shaped sheet unit 100, the adjacent arc-shaped sheet units 100 reversely slide along the circumferential direction of the annular bare stent, and the adjacent two arc-shaped sheet units 100 are restrained and limited by the circumferential restraint limiting structure to not slip (keep the end part laminated state) each other (the arc-shaped sheet units 100 of the annular bare stent at the end part of the vascular stent are connected with at least two points of the middle-section stent 2, and certain path restraint can be carried out on the scattered and sprung and contracted gathering of each arc-shaped sheet unit 100, so that the arc-shaped sheet units 100 are prevented from being scattered or contracted irregularly).
In the annular bare stent at the end part of the vascular stent, the adjacent arc-shaped sheet units 100 have the movement trend of mutually dispersing and bouncing due to the design of arc streamline surfaces, and the radial outer surfaces of the arc-shaped sheet units 100 are attached to the inner membrane of the blood vessel without a film coating due to the elastic pulling force of the middle section stent 2. Compared with a diamond ring or M-shaped ring stent connected with a tectorial membrane in the prior art, the end structure of the vascular stent after being opened is characterized in that:
(1) The end part structure of the vascular stent in the embodiment is an annular bare stent, has no tectorial membrane structure, and does not influence the climbing attachment of endothelial cells on the radial outer surface of the bare stent, so that the positioning effect in the blood vessel is better, and the vascular stent is not easy to shift for a long time on the basis of not shifting for a short time;
(2) The annular bare stent at the end part of the vascular stent of the embodiment is of a monolithic structure formed by combining a plurality of arc-shaped sheet units 100, and the end part of the annular bare stent has no large grid or mesh, so that vascular endothelial cells can be prevented from proliferating inwards through the mesh at the end part of the bare stent to block blood vessels, on the basis, the middle section stent 2 can also be provided as a covered stent, further the vascular endothelial cells can be prevented from proliferating inwards through the mesh of the middle section stent to block blood vessels, and when the middle section stent 2 is a covered stent, the covered stent can be used as a peripheral vascular sealing stent for the intra-cavity isolated treatment of peripheral vascular lesions;
(3) The annular bare stent at the end part of the vascular stent in the embodiment is of a monolithic structure formed by combining a plurality of arc-shaped sheet units 100, has no sharp part, has small stimulation to the vascular intima and avoids damaging the vascular intima.
Therefore, the vascular stent provided by the embodiment relieves the problems that the peripheral vascular stent of the existing structure type cannot comprehensively coordinate high flexibility, high radial supporting force at the far end and the near end, reduces the irritation to the intima of the blood vessel and prevents the displacement function after long-term use, and meanwhile, the flexibility of the vascular stent is not influenced.
In particular, in the present embodiment, "the proximal stent 1 and/or the distal stent 3 are" in the form of a ring-shaped bare stent "and/or" includes any of the following meanings: (1) only the proximal stent 1 is the annular bare stent, (2) only the distal stent 3 is the annular bare stent, (3) both the proximal stent 1 and the distal stent 3 are the annular bare stents.
In the embodiment of the present invention, the above-mentioned circumferential constraint limit structure has various specific optional structures, including but not limited to a structure of connecting a plurality of traction wires between two adjacent arcuate sheet units 100, but in this design structure, a plurality of groups of traction wires need to be respectively connected between every two adjacent arcuate sheet units 100 in sequence, and the manufacturing and assembling processes are complex, so that the design is not the preferred design manner of the present embodiment.
In many design manners of this embodiment, referring to fig. 4 and 5, with reference to other drawings in fig. 1 to 7, it is preferable that the circumferential restraining and limiting structure includes a limiting slot 110 and a limiting protrusion 120 respectively provided on each arcuate sheet unit 100; the limiting long groove 110 extends along the circumferential direction of the annular bare bracket, and two ends of the limiting long groove in the length direction are closed; in each two adjacent arc-shaped sheet units 100 in the circumferential direction of the annular bare bracket, the limiting protrusion 120 of one arc-shaped sheet unit 100 is slidably limited in the limiting long groove 110 of the other arc-shaped sheet unit 100. In the radial shrinkage and release process, the limiting protrusion 120 is limited under the structure of the limiting elongated slot 110, so that the adjacent two arc-shaped sheet units 100 are limited not to slip, and in the structure, the limiting and limiting effect can be realized only by a group of limiting elongated slots 110 and limiting protrusions 120 between the adjacent two arc-shaped sheet units 100, so that the limiting and limiting device has a simple structure and is easy to manufacture.
Further, for the specific arrangement positions of the above-mentioned spacing elongated slot 110 and spacing protrusion 120 on the arcuate sheet-like unit 100, there are also various alternative structures, wherein, in order to avoid the spacing protrusion 120 from stimulating the patient's vascular intima, it is preferable that the spacing elongated slot 110 is communicated with the radial outer surface of the arcuate sheet-like unit 100, the spacing protrusion 120 is protruded on the radial inner surface of the arcuate sheet-like unit 100, and in every two adjacent arcuate sheet-like units 100 in the circumferential direction of the annular bare stent, the spacing protrusion 120 of the arcuate sheet-like unit 100 laminated on the radial inner side is slidingly limited in the spacing elongated slot 110 of the arcuate sheet-like unit 100 laminated on the radial outer side. The specific connection manner between the limiting elongated slot 110 and the limiting protrusion 120 includes, but is not limited to, setting a limiting end at the free end of the limiting protrusion 120 (the end of each limiting protrusion 120 deviating from the arc-shaped sheet unit 100), wherein the cross section of the cavity inside the limiting elongated slot 110 is in a step shape with large bottom surface space and small top surface space of the slot body, the limiting protrusion 120 extends into the limiting elongated slot 110, and the limiting end set at the free end of the limiting protrusion is blocked in the space with large bottom surface of the slot body. However, the assembly of the design manner is also complicated, so in this embodiment, it is preferable that the limiting slot 110 is a through slot radially penetrating through the corresponding arcuate slot 100, each limiting protrusion 120 penetrates through the corresponding limiting slot 110, and a limiting end for preventing the limiting protrusion 120 from separating from the limiting slot 110 is disposed at one end (the free end) of each limiting protrusion 120 facing away from the arcuate slot 100.
In addition, in this embodiment, in order to avoid interference of sliding motion of the limiting protrusion 120 along the limiting slot 110 in each two adjacent arc-shaped sheet units 100 in the circumferential direction of the annular bare stent during transition of the vascular stent to the radially compressed state, it is preferable that the axial height of the limiting slot 110 of one arc-shaped sheet unit 100 and the axial height of the limiting slot 110 of the other arc-shaped sheet unit 100 in the circumferential direction of the annular bare stent in each two adjacent arc-shaped sheet units 100 in the circumferential direction of the annular bare stent are different. And further preferably, the axial heights of the limiting long grooves 110 of any two arc-shaped sheet units 100 in the circumferential direction of the annular bare stent are different, after the annular bare stent is circumferentially unfolded, the limiting long grooves 110 are arranged in a step shape, so that the annular bare stent can be ensured to be contracted to a cylinder shape with the minimum diameter when being radially compressed, the annular bare stent is convenient to convey, and the annular bare stent can be ensured to easily pass through a tortuous blood vessel to reach a designated position in the conveying process, so that the vascular damage to a patient is small.
In addition, in this embodiment, it is preferable that the annular bare stent further includes a unidirectional limiting structure, and when the annular bare stent is shifted from the radially contracted state to the free release state, the adjacent two arcuate sheet units 100 slide relatively in one direction and in opposite directions along the circumferential direction of the annular bare stent under the limitation of the unidirectional limiting structure. The radial supporting force of the annular bare support after being released can be increased through the design of the structure, and the anti-displacement effect is further improved. In addition, the vascular stent has the function of expanding the blood vessel by matching with the instrument besides the function of repairing the blood vessel after being implanted into the blood vessel of a patient, specifically, if the blood vessel of the patient is narrow and endangers the health, or the implantation of the later-stage instrument is influenced, the end stent of the vascular stent can be further expanded by utilizing the balloon instrument after being implanted into the vascular stent, and when the end stent is expanded in place, the one-way limiting structure is used for positioning so as to achieve the function of completely fitting the blood vessel intima, and meanwhile, the circumferential constraint limiting structure is used for avoiding the blood vessel from being excessively damaged by expansion to cause the blood vessel to generate a new interlayer when the blood vessel is expanded. In addition, the vascular stent provided by the application can be applied to a reducing blood vessel besides an equal-diameter blood vessel, specifically, when the vascular stent is released, the diameter of the end stent of the existing vascular stent structure is limited by the release diameter of the middle stent 2, if the vascular stent is an equal-diameter blood vessel, the end stent can be naturally attached to a blood vessel intima for radial support, but if the diameter of the blood vessel at the position of the middle stent 2 is thinner than that of the end stent, the end stent is difficult to be completely attached to the blood vessel intima, the problem can not be overcome by a common vascular stent, and only the other end vascular stent can be spliced for new release, but by adopting the vascular stent provided by the embodiment, after the release, the end stent of the vascular stent can be further expanded by using a balloon apparatus, and when the end stent is expanded in place, the one-way limiting structure is positioned so as to achieve the function of completely attaching the blood vessel intima, and simultaneously, when the expansion is performed, the circumferential limiting structure is used for preventing the blood vessel from being excessively damaged, so that a new interlayer is generated in the blood vessel.
In this preferred embodiment, it is further preferred that the one-way limiting structure includes an abutment portion provided to each arcuate sheet-like unit 100 and a plurality of rows of ratchet structures 130 provided to each arcuate sheet-like unit 100; these ratchet structures 130 are arranged in parallel in the circumferential direction of the annular bare stent and are inclined toward the end direction of the adjacent arcuate sheet units 100; in the static structure, in every two adjacent arc-shaped sheet units 100 in the circumferential direction of the annular bare stent, the abutting part of one arc-shaped sheet unit 100 abuts against a row of ratchet structures 130 of the other arc-shaped sheet unit 100, so as to prevent the adjacent two arc-shaped sheet units 100 from sliding in opposite directions along the circumferential direction of the annular bare stent.
In order to avoid the above-mentioned unidirectional limiting structure from stimulating the intima of the blood vessel, it is further preferable that the ratchet structure 130 is provided on the inner side surface of the arcuate sheet-like unit 100, and in the static structure, in each adjacent two arcuate sheet-like units 100 in the circumferential direction of the annular bare stent, the abutting portion of the arcuate sheet-like unit 100 laminated on the radially inner side surface abuts against a row of ratchet structures 130 of the arcuate sheet-like units 100 laminated on the radially outer side surface to prevent the adjacent two arcuate sheet-like units 100 from sliding in the circumferential direction of the annular bare stent; the abutting portion may be a protrusion structure provided on the outer side surface of the arcuate sheet-like unit 100, or may be another structure, and it is preferable to have the abutting portion be an end surface of the arcuate sheet-like unit 100 laminated on the radially inner side surface of each adjacent two arcuate sheet-like units 100 in the circumferential direction of the annular bare stent for simplicity of the structure.
In addition, in the embodiment of the present invention, it is preferable that each of the arcuate sheet units 100 is made of a super-elastic material, including but not limited to a metal material such as nitinol or other super-elastic polymer materials, so as to further ensure that the stent has a good radial supporting force, and the stent portion of the middle stent 2 may be made of the same material as the arcuate sheet units 100.
Finally, it should be noted that: in the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are only required to be seen with each other; the above embodiments in the present specification are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.