EXPANDABLE STENT EQUIPPED WITH A SLEEVE AND METHOD OF MANUFACTURING SUCH STENT Russian patent published in 2023 - IPC A61F2/24 A61F2/91 

FIELD: medical equipment.
SUBSTANCE: invention relates specifically to stents used for treatment of aneurysms, as well as for fixation and support of replacement valves. An expandable stent equipped with a sleeve comprises a tubular body and a sleeve. The tubular body is made with the first and second axial ends, a lattice peripheral wall and at least two holders, which, when the tubular body expands radially from the compressed state to the expanded state, protrude in the radial direction from the lattice peripheral wall, and the free end of each holder is made with the possibility of displacement in the radial direction relative to the adjacent lattice peripheral wall. The sleeve extends from the first axial end of the tubular body and circumferentially covers at least part of the radial outer surface of the lattice peripheral wall between the free ends of the holders and the first axial end of the tubular body; covers the spaces between the parts of the lattice peripheral wall adjacent to the holders, and the free ends of the holders; and attached to any of the following: (i) holders; or (ii) a tubular body between the free ends of the holders and the second axial end of the tubular body. When the tubular body is in a compressed state, the sleeve: (i) in the region that radially overlaps the lattice peripheral wall, has a regular round cylindrical shape; and (ii) in the regions that radially cover the holders, defines radially outwardly extending bulges. The bulges provide pockets into which the holders extend upon radial expansion of the tubular body in the direction of the expanded state, so that upon radial expansion of the tubular body in the direction of the expanded state and subsequent protrusion of the holders in the radial direction from the lattice peripheral wall of the sleeve part, which surround the lattice peripheral wall and holders, diverge outward in the radial direction. In accordance with the second embodiment of the expandable stent, the sleeve covers the holders; and, when the tubular body is in a compressed state: in the area of the sleeve that overlaps the lattice peripheral wall in the radial direction, has a regular round cylindrical shape; and in areas of the sleeve that radially cover the holders, defines radially outwardly extending bulges providing pockets between the sleeve and the associated holders, so that when the holders protrude radially from the lattice peripheral wall, the holders extend into the pockets provided with the bulges. The method for manufacturing an expandable stent equipped with a sleeve includes the following steps: providing an expandable stent containing a tubular body with first and second axial ends, a lattice peripheral wall and at least two holders, which, when the tubular body expands radially from a compressed state to an expanded state protrude in the radial direction from the lattice peripheral wall, and the free end of each holder is configured to enable displacement in the radial direction relative to the adjacent lattice peripheral wall; applying a polymer to the first cylindrical core by electrospinning to create a sleeve; stretching the sleeve over a second cylindrical core which defines at least two radially outwardly extending bulges symmetrically spaced around the circumference of the second cylindrical core; heating the sleeve so that the sleeve takes the form of a second cylindrical core with bulges; and positioning the sleeve over the stent so that the bulges formed in the sleeve cover the stent holders in the radial direction.

EFFECT: invention enables protrusion of the holders without the need for simultaneous elastic deformation/stretching of the sleeve, reduces the risk of snagging between the holders and the sleeve during the protrusion of the holders and thereby reduces the risk of rupture of the sleeve, promotes sealing of the sleeve against the inner wall of the lumen of the blood vessel to prevent leakage of blood flow between the stent and the wall of the lumen in close proximity to protruding holders.

13 cl, 6 dwg