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EP-4164555-B1 - INTRAVASCULAR STENT

EP4164555B1EP 4164555 B1EP4164555 B1EP 4164555B1EP-4164555-B1

Inventors

  • WANG, YONGGANG

Dates

Publication Date
20260506
Application Date
20200616

Claims (13)

  1. An intravascular stent, capable of changing to an expanded state with an expanded second cross-sectional diameter from a compressed state with a first cross-sectional diameter, the intravascular stent comprises a positioning segment and a supporting segment connected in the axial direction of the intravascular stent, the positioning segment comprises a plurality of first repeating elements (11) distributed in the circumferential direction along the intravascular stent, the supporting segment comprises a first supporting part (41), a second supporting part (51) and a third supporting part (61) connected successively in the axial direction of the intravascular stent, and the positioning segment is connected with the first supporting part (41), wherein the supporting segment comprises at least five supporting units (21) and at least four connecting units (22) connected in the axial direction of the intravascular stent, the at least five supporting units (21) each comprising a plurality of second repeating elements (211) distributed in the circumferential direction along the intravascular stent, and the at least four connecting units (22) each comprise a plurality of connectors (221) distributed in the circumferential direction along the intravascular stent, the structure of the first repeating elements (11) and the second repeating elements (211) are of any shape capable of forming holes, for example V shape, grid shape, rhombus and the like, whereby closed loops are formed when the number of the connectors (221) in a row is equal to the number of the second repeating elements (211) of the supporting units in adjacent rows and each second repeating element (211) is connected to a connector (221) and whereby open loops are formed when the number of connectors (221) in a row is equal to or smaller than half of the number of second repeating elements (211), and one out of two second repeating elements (211), or less, is connected to a connector (221), the structure formed by two adjacent second repeating elements (211) of the first supporting part (41) is alternately arranged by closed-loops and open-loops in the axial direction, the structure formed by two adjacent second repeating elements (211) of the second supporting part (51) is open-loops, the structure formed by two adjacent second repeating elements (211) of the third supporting part (61) is closed-loops.
  2. The intravascular stent according to claim 1, is characterized in that , the length of the first supporting part (41) accounts for 0.4-0.6 of the total length of the supporting segment.
  3. The intravascular stent according to any one of the preceding claims, is characterized in that , the length of the third supporting part (61) accounts for 0.05-0.15 of the total length of the supporting segment.
  4. The intravascular stent according to any one of the preceding claims, is characterized in that , the second repeating elements (211) of the supporting unit (21) located at front ends of the supporting segments are one-to-one correspondingly connected with the second repeating elements (211) of another adjacent supporting unit (21) to form close-loop structures.
  5. The intravascular stent according to any one of the preceding claims, is characterized in that , a front end of the supporting segment is connected with a plurality of first developing units (4), the number of the first developing units (4) being 3 to 10.
  6. The intravascular stent according to any one of the preceding claims, wherein, a rear end of the supporting segment is connected with a plurality of second developing units (5) , the number of the second developing units (5) being 3 to 10.
  7. The intravascular stent according to any one of the preceding claims, is characterized in that , a front end of the positioning segment is connected with a plurality of third developing units (6) , the number of the third developing units (6) being 3 to 10.
  8. The intravascular stent according to any one of the preceding claims, is characterized in that , holes formed by the first repeating elements (11) are larger than holes formed by the second repeating elements (211) in size so as to avoid the formation of thrombosis caused by a small hole of the intravascular stent or effect on the blood flow of the opposite iliac vein caused by the positioning segment.
  9. The intravascular stent according to any one of the preceding claims, is characterized in that , the number of the first repeating elements (11) is less than the number of the second repeating elements (211) of each of the at least two supporting units (21).
  10. The intravascular stent according to any one of the preceding claims, is characterized in that , an angle between the plane formed by the front ends of the plurality of first repeating elements (11) and the axis of the intravascular stent is 45° ~ 90°.
  11. The intravascular stent according to any one of the preceding claims, is characterized in that , the material of the intravascular stent is one or more selected from stainless steel, memory alloy, nickel-titanium alloy, titanium alloy, tantalum alloy, cobalt-chromium alloy, biodegradable metal, biodegradable polymer, magnesium alloy, pure iron.
  12. The intravascular stent according to any one of the preceding claims, is characterized in that , an angle between an extending direction of the positioning segment and the axis of the intravascular stent is 0° ~ 60°.
  13. The intravascular stent according to any one of the preceding claims, is characterized in that , the intravascular stent is configured to be used for an iliac vein stent.

Description

Technical Field of the Invention The present disclosure belongs to the field of medical apparatus and instruments, specifically to an intravascular stent. Background of the Invention Venous disease is most common in vascular surgical diseases, especially lower extremity deep vein thrombosis and lower extremity great saphenous vein varicosity are even more common. And a big reason for the cause of the formation of these two diseases is that it is caused by iliac vein compression. Iliac vein compression syndrome (IVCS) refers to that iliac vein is compressed by iliac artery, leading to intracavity adhesion, stenosis or occlusion, thereby resulting in a series of clinical symptoms of the syndrome, also known as May-Thurner, Cockett syndrome. The incidence of iliac vein compression syndrome is in 20% to 34%. Venous compression has always been solved by operation in the treatment, which has been difficult to be accepted by patients due to the need for abdominal surgery and large trauma, so the number of cases reported in China is few. It results in that lower extremity swelling of many patients cannot be resolved, and some patients suffer venous thrombosis due to blood stasis. At present, many Chinese and foreign research reports show that there is few stent designed for the iliac vein compression syndrome. A stent for the treatment of iliac vein stenosis (utility model: 201320053442.3) is woven by nickel-titanium wires into a latticed reticulated tube, the orifice of the front end of the reticulated tube is a bevel, an angle between the bevel and the cross section of the reticulated tube is 40 degrees, the reticulated tube has an oval mark ring thereon, to realize the accurate positioning. However, none of the iliac venous stents is applicable to the iliac veins due to their support strength and effect on blood flow. US2019/247209A1 discloses a tapering stent. The stent includes a high radial force segment and a highly flexible segment, where the diameters of the high radial force segment and the highly flexible segment are different. For example, the stent may be formed from a tube having varying diameters as it extends distally combined with increased strut density to achieve increased flexibility distally while reducing loss of radial stiffness. The stent may further be placed with an additional stent segment, where the additional stent segment has a radial force similar to the radial force of the highly flexible force segment. The document is not describing a structure formed by two adjacent second repeating elements of a first supporting part wherein closed-loops and open-loops in the axial direction are alternately arranged. Summary of the Invention The technical problem to be solved by the present disclosure is to overcome the disadvantage of the prior art, and to provide intravascular stents of different structures. To solve the above technical problems, the present disclosure employs the following technical schemes: An intravascular stent, capable of changing to an expanded state with an expanded second cross-sectional diameter from a compressed state with a first cross-sectional diameter, wherein,the intravascular stent comprises a positioning segment and a supporting segment connected in the axial direction of the intravascular stent,the positioning segment comprises a plurality of first repeating elements distributed in the circumferential direction along the intravascular stent,the supporting segment comprises a first supporting part, a second supporting part and a third supporting part connected successively in the axial direction of the intravascular stent, and the positioning segment is connected with the first supporting part, the supporting segment comprises at least five supporting units and at least four connecting units connected in the axial direction of the intravascular stent, the at least five supporting units each comprising a plurality of second repeating elements distributed in the circumferential direction along the intravascular stent, and the at least four connecting units each comprise a plurality of connectors distributed in the circumferential direction along the intravascular stent,the structure of the first repeating elements and the second repeating elements are of any shape capable of forming holes, for example V shape, grid shape, rhombus and the like, whereby closed loops are formed when the number of the connectors in a row is equal to the number of the second repeating elements of the supporting units in adjacent rows and each second repeating element is connected to a connector and whereby open loops are formed when the number of connectors in a row is equal to or smaller than half of the number of second repeating elements, and one out of two second repeating elements, or less, is connected to a connector,the structure formed by two adjacent second repeating elements of the first supporting part is alternately arranged by closed-loops and open-loops in the axial direc