RU98110568A - Wicker stent - Google Patents

Claims (1)

1. A radially self-expanding stent adapted for implantation in a canal in the body, comprising the first and second sets of mutually counter-rotating metallic filaments that are woven together and form a tubular stent body having two ends, which mechanically shifts toward the first radially expanded configuration, in which it is not held by externally applied forces and can be held in a second radially compressed configuration, in which in the first configuration indicated, the angle α between the threads at point n The intersections at the midpoint of the stent are less than 90 ^° and in which some or all of the threads at the ends of the body are fixed together in pairs, each of which consists of counter-rotating threads so that the angle at which the threads are fixed using a metal bead having a diameter at least 1.3 times the average diameter of a single thread, is within the range of α-10 - α + 10.
2. The stent according to claim 1, in which the angle α is in the range of 60 - 90 ^o , preferably 65 - 85 ^o , most preferably 70 - 80 ^o . 3. A stent according to any one of the preceding claims, in which the angle at which the ends of the threads are fixed is in the range α-5 - α.
4. A stent according to any one of the preceding claims, which has a biocompatible polymer coating, preferably from a polymer having an additional zwitterionic group, more preferably an ammonium phosphate ester group.  5. A stent according to any one of the preceding paragraphs., In which the threads freely slide along each other at intersection points.  6. A stent according to any one of the preceding claims, in which each bead has a diameter of more than twice the average diameter of each thread.  7. A stent according to any one of the preceding claims, in which the filaments are made of a shape memory alloy, and in which the stent acquires the first radially expanded configuration below the transition temperature, and when the stent is heated to a temperature above the transition temperature, the stent seeks to accept the most radially expanded a configuration in which the diameter and / or stent resistance to radial compression increases.  8. A method of manufacturing a stent according to any one of the preceding paragraphs. by weaving threads around the first mandrel for manufacturing an elongated preform, cutting off a part of the preform of a pre-selected length, placing the cut part on a second mandrel that has a diameter within the range of (0.8 to 1.25) · d (where d is the diameter of the stent in its radially straightened state) so that one end of the braided part extends beyond the end of the second mandrel, and in the method the protruding ends of at least some of the threads are connected to each other in counter-rotating pairs, whereby ach pair of counter-rotating filaments is connected to a bead of metal having a diameter at least 1.2 times larger than the average diameter of the individual filaments.  9. The method according to p. 8, in which the ends of the threads are joined together by welding, preferably using a technique without filler material.  10. The method according to claim 9, in which the stent is annealed before or after the welding step.  11. The method according to any one of claims 8 to 10, in which all the threads that need to be welded at one end of the stent are simultaneously joined into their respective pairs and, in a separate step, all the threads that need to be welded at the other end of the stent, join in their respective pairs.  12. The method according to any one of claims 8 to 11, in which the stent is then coated with a liquid coating composition, and the coating dries to form a tightly attached coating of a biocompatible polymer.  13. The method of claim 12, wherein the polymer has additional zwitterionic groups, preferably ammonium phosphate ester groups.  14. The method according to PP.12 or 13, in which the coating is dried using the direction of gas flow through the stent in the axial direction.  15. The transplant, comprising at least one stent according to any one of claims 1 to 7, surrounded by a sleeve, preferably made of elastomeric material, and attached to it.  16. The combination of a stent according to any one of claims 1 to 7 or a graft according to Claim 15, wherein the stent or graft is in a radially compressed configuration and an introduction device, wherein the introduction device includes an inner follower tube including an inner clearance of the guide wire for insertion the guide wire and the outer sleeve, the sleeve and the pusher forming between them an annular space in which the stent being held is surrounded substantially along its entire length along the axis of the sleeve, and at least one end of the stent is lives in the annular space between the sleeve and the pusher.