EXPANDABLE STENT AND METHODS OF CONTRACTION AND EXPANSION OF SUCH A STENT Russian patent published in 2020 - IPC A61F2/24 A61F2/86 

FIELD: medical equipment.

SUBSTANCE: group of inventions relates to an expandable stent and methods of tightening and expanding such a stent. Expandable stent comprises a cylindrical wall consisting of latticed elements, connected to each other; at least one first link and at least one second link. At least one first link comprises first nonlinear element, which is connected at each of its axial ends with mesh element on corresponding first joints; and second nonlinear element, connected at each axial end to (i) meshed element or (ii) first element of first link; and at least one partition-like element extending between first and second elements. At least one second link comprises a first non-linear element which is connected at each of its axial ends to the grate member; and second nonlinear element, connected at each axial end to meshed element; and at least one partition-like element extending between first and second elements. Second element of the first link is mainly U-shaped and passes from its axial ends in direction (i) of the first axial end of the stent and (ii) in the direction of the partition of the first link. Second element of the second link is mainly U-shaped and passes from its axial ends in direction (i) of the first axial end of the stent and (ii) in the direction of the partition of the second link. First link is located on the second axial end of the stent, and the second link is located (i) at the distance along the axis from the first link in direction of the first axial end of the stent and (ii) is aligned along the axis with the first link. First element and second element of each of first and second links are connected to grid elements only on their axial ends, thus, during radial expansion of stent from radially contracted state under action of external force tension in (i) partition of first link and (ii) element in form of partition of second link provides protrusion radially outward of second elements of both first and second links respectively. Method of constriction of said stent includes steps of: providing primary deformation of latticed elements, which includes (i) relative angular displacement of latticed elements on their connection points to each other and common deformation of lattice elements to flattened state and (ii) interconnection of adjacent first elements of adjacent first links; and providing secondary deformation of lattice elements, wherein additional compression of flattened lattice elements provides plastic deformation of rigid sections of first elements of each first link. Method for extending the above stent involves the steps of: placing a stent, which is preliminarily pulled, through the heart valve, wherein the first links and the second links extend beyond the free ends of the valve flaps; expansion of the stretching device inside the stent with providing (i) expansion of the stent and radial protrusion (ii) of the first and second links relative to the adjacent latticed elements; and stent displacement along axis relative to valve with provision of first links or second links resting on free ends of valve shutters, wherein free ends of resting first links or second links are located at a distance from the intersection of valve flaps and aortic root.

EFFECT: invention provides improved fixation of a stent with a vessel wall structure.

16 cl, 10 dwg