Peripheral vascular stent and preparation method thereof and application thereof
The peripheral vascular stent comprises scaffolding holding units and a membrane, each scaffolding holding units is formed of a closed ring shape wire; the membrane is covered on scaffolding holding units, the flexibility of the membrane is greater than that of the scaffolding holding units, between the wires of the same scaffolding holding unit and/or between two adjacent scaffolding holding units is provided a plurality of hollowed-out areas on the membrane, and two adjacent scaffolding holding units are only connected by the membrane beyond the hollowed-out areas. The peripheral vessel stent can meet the mechanical performance requirements, has a proper radial support force and good flexibility, and can well reduce the in-stent chronic external expansion force, has the advantages of little impact on blood flow, little injury to the vascular wall, and less likely to cause secondary thrombosis.
1 . A peripheral vascular stent, having an expanded state and a contracted state, the peripheral vascular stent having a larger inner diameter in the expanded state than that in the contracted state; wherein, the peripheral vascular stent comprises: scaffolding holding units, the scaffolding holding units are a plurality of scaffolding holding units arranged at intervals along an axial direction of the peripheral vascular stent, each of the scaffolding holding units is formed of a wire and is in a closed ring shape, and each of the scaffolding holding units comprises a plurality of peaks and valleys regularly arranged in the circumferential direction, with two adjacent peaks forming a cycle; a membrane, the membrane is covered on the plurality of scaffolding holding units, the flexibility of the membrane is greater than that of the scaffolding holding units, the membrane between the wires of the same scaffolding holding unit and/or between two adjacent scaffolding holding units is provided with a plurality of openings; the openings comprise: first openings located within the peaks of each scaffolding holding unit, second openings located within the valleys of each scaffolding holding unit, a plurality of third openings located between two adjacent scaffolding holding units and in communication with the first openings and the second openings respectively, wherein each of the third openings is mutually independent and only in communication with the nearest first openings and the nearest second openings; two adjacent scaffolding holding units are only connected by the membrane beyond the openings and without metal connection; between two adjacent scaffolding holding units, one scaffolding holding unit and the other scaffolding holding unit are staggered on a circumferential surface, and a staggered distance between the nearest two peaks in the adjacent scaffolding holding units is less than one-half cycle; between two adjacent scaffolding holding units, the valley bottoms of one scaffolding holding unit and the nearest peak tops of the other scaffolding holding unit are only connected by strip-shaped membranes; wherein in a clockwise direction, each of the scaffolding holding units and the adjacent scaffolding holding unit are staggered on the circumferential surface and the staggered distance between any two adjacent scaffolding holding units is the same.
2 . The peripheral vascular stent according to claim 1 , wherein, the staggered distance is less than or equal to a quarter of the cycle.
3 . The peripheral vascular stent according to claim 1 , wherein, an axis of each scaffolding holding unit coincides with an axis of the peripheral vascular stent.
4 . The peripheral vascular stent according to claim 1 , wherein, the first openings are surrounded by first walls and second walls connected by upper ends thereof, and the second openings are surrounded by third walls and fourth walls connected by lower ends thereof, the third openings are surrounded by fifth walls respectively connected to the lower ends of the first walls and the upper ends of the fourth walls, and sixth walls respectively connected to the lower ends of the second walls and the upper ends of the third walls.
5 . The peripheral vascular stent according to claim 4 , wherein, when the peripheral vascular stent is split along its axial direction and spread into a plane shape, two nearest first walls of two adjacent scaffolding holding units are on a first straight line.
6 . The peripheral vascular stent according to claim 4 , wherein, angles between the first walls and the second walls are acute angles.
7 . The peripheral vascular stent according to claim 4 , wherein, when the peripheral vascular stent is split along its axial direction and spread into a plane shape, the first walls and the third walls are parallel, the second walls and the fourth walls are parallel, and a plurality of second walls are parallel.
8 . The peripheral vascular stent according to claim 1 , wherein, the membrane is wrapped on an outer side and/or an inner side of the scaffolding holding units.
9 . The peripheral vascular stent according to claim 1 , wherein, the membrane comprises an inner membrane located on the inner side of the scaffolding holding units and an outer membrane located on the outer side of the scaffolding holding units, the inner membrane and the outer membrane are fixedly connected, and the scaffolding holding units are wrapped between the inner membrane and the outer membrane.
10 . The peripheral vascular stent according to claim 9 , wherein, the inner membrane and the outer membrane that are in contact are thermally melted to form the membrane.
11 . The peripheral vascular stent according to claim 1 , wherein, the inner diameter of the peripheral vessel stent in the expanded state is gradually tapered from one end to the other end.
12 . The peripheral vascular stent according to claim 1 , wherein, the membrane is coated with drugs.
13 . The peripheral vascular stent according to claim 1 , wherein, a material used for the scaffolding holding units is selected from the group consisting of stainless steel, memory alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, biodegradable metal, biodegradable polymer, magnesium alloy, pure iron, and combinations thereof.
14 . The peripheral vascular stent according to claim 13 , wherein, the material of the scaffolding holding units is nickel-titanium alloy.
15 . The peripheral vascular stent according to claim 1 , wherein, a material used for the membrane is selected from the group consisting of polytetrafluoroethylene, polyether block amide, polyimide, bioabsorbable medical materials, and combinations thereof.
16 . The peripheral vascular stent according to claim 1 , wherein, the membrane is polytetrafluoroethylene microporous membrane.
17 . A method for preparing a peripheral vascular stent according to claim 1 , wherein, fixing the membrane and the scaffolding holding units with each other, and then opening a plurality of openings on the membrane; or opening a plurality of openings on the membrane, and then fixing the membrane and the scaffolding holding units with each other; or respectively arranging an inner membrane and an outer membrane on the inner side and outer side of the scaffolding holding units, wrapping the scaffolding holding units between the inner membrane and the outer membrane by heating the inner membrane and the outer membrane, thermally melting the inner membrane and the outer membrane beyond the scaffolding holding units to form into an integral membrane, and then opening a plurality of openings on the membrane; or respectively opening a plurality of openings on an inner membrane and an outer membrane, then respectively arranging the inner membrane and the outer membrane on the inner side and outer side of the scaffolding holding units, aligning the openings on the inner membrane with the openings on the outer membrane to form the third openings that are mutually independent, wrapping the scaffolding holding units between the inner membrane and the outer membrane by heating, and thermally melting the inner membrane and the outer membrane beyond the scaffolding holding units to form into an integral membrane.
18 . A method for treating peripheral artery disease, the method comprising placing the peripheral vascular stent according to claim 1 into a peripheral artery.