Asymmetric venous stent with friction force increased in anchoring area

Abstract

The invention relates to an asymmetric vein stent capable of increasing friction force in an anchoring area, which is characterized in that a near-end petal-shaped stent is positioned at the confluence of double iliac veins at the near end of the vein, and a high-radial-supporting-force stent is positioned at the total iliac vein; the far-end woven stent is positioned at the far end of the iliac total vein and the iliac external vein and is a woven stent with high flexibility, and a high-friction metal wire is woven into the far-end woven stent; the radial support force of the three parts of the stent is gradually increased according to the sequence: the near-end petal-shaped stent, the strong radial support force stent and the far-end woven stent; the far-end woven stent is woven by metal wires, and the expansion diameter of the stent is slightly larger than the target vein diameter but smaller than that of the stent with the strong radial supporting force. The partial expansion diameter of the high-friction metal wire and the contact area of the high-friction metal wire and the blood vessel wall are larger than those of the common woven stent metal wire; the group of metal connecting short rods are connected with the strong radial supporting force stent and the far-end woven stent through laser welding.

Description

Technical Field

[0001] The invention relates to a venous stent, in particular to an asymmetric venous stent with increased friction in an anchoring area, belonging to the technical field of vascular stents. Background Art

[0002] Non-thrombotic iliofemoral venous stenosis and occlusive disease is one of the most common and important diseases in venous surgery, which significantly affects the patient's limb function and quality of life, and brings huge medical and labor burdens. With the innovation of endovascular technology and the development of interventional materials, percutaneous stent angioplasty has gradually replaced traditional open bypass surgery and become an important means of clinical treatment of deep vein disease. It not only has less trauma and faster recovery, but also has a much higher patency rate than traditional bypass surgery, with an initial patency rate of up to 70% in 3 years.

[0003] The current medical market applications include laser engraved venous stents and braided venous stents. For laser engraved venous stents, the entire stent has the same pressure resistance, which often results in the stent collapse in the compressed area, while the stent lacks flexibility in the uncompressed area; in addition, the stent is prone to angles at the bends of the iliac vein, which may increase damage to the intima, cause intimal hyperplasia and recurrence of thrombosis in the stent. For braided venous stents, the stent has better flexibility and less damage to the tube wall, but the radial support force is insufficient, and complications such as stent displacement may occur. Summary of the invention

[0004] The purpose of the present invention is to provide an asymmetric venous stent with increased friction in the anchoring area, which can ensure that the stent has the characteristics of not affecting the contralateral venous blood flow at the confluence of the two iliac veins, strengthening the radial support force of the proximal iliac vein, strong flexibility in the cross-joint segment, high flexibility in the distal anchoring area and strong friction.

[0005] The present invention adopts the following technical solutions:

[0006] An asymmetric venous stent with increased friction in an anchoring area comprises a three-part stent and a group of metal connecting short rods 5; the three parts of the stent are respectively: a proximal petal-shaped stent 1, a strong radial support stent 2, and a distal braided stent 4 connected in sequence from the proximal end to the distal end; the proximal petal-shaped stent 1 is positioned at the junction of the two iliac veins of the iliac vein, the strong radial support stent 2 is positioned at the easily compressed segment of the common iliac vein, and the distal braided stent 4 is positioned at the distal end of the common iliac vein and the external iliac vein; the radial support force of the three parts of the stent increases in this order: the proximal petal-shaped stent 1 < the distal petal-shaped stent 2 ... The end braided stent 4 is less than the strong radial supporting force stent 2; the distal braided stent 4 is formed by weaving metal wires, and the expanded diameter of the stent is slightly larger than the target vein diameter but smaller than the strong radial supporting force stent 2; high friction metal wires 401 and ordinary braided stent metal wires 402 are woven into it at the same time, and the expanded diameter and contact area with the blood vessel wall of the high friction metal wires 401 are larger than those of the ordinary braided stent metal wires 402; the group of metal connecting short rods 5 are connected to the two parts of the strong radial supporting force stent 2 and the braided stent 4 by laser welding; the short rods can be straight or curved.

[0007] Preferably, the proximal end of the proximal petal-shaped stent 1 is in the shape of a petal that is slightly opened toward the periphery.

[0008] Preferably, the proximal petal-shaped stent 1 is an open-design bare metal stent manufactured by laser engraving technology; the material includes but is not limited to one of stainless steel, cobalt-chromium alloy, platinum-chromium alloy, and magnesium alloy.

[0009] Furthermore, the strong radial support stent 2 is a bare metal stent manufactured by laser engraving technology, the expanded diameter of the stent is larger than the target vein diameter, the metal wall thickness and metal coverage are larger than the distal braided stent 4, and the length is 2-4 cm.

[0010] Preferably, the distal braided stent 4 has a length of 4-6 cm and covers the iliac vein crossing the joint.

[0011] Preferably, the high friction metal wire 401 and the common braided stent metal wire 402 have the same coverage area.

[0012] Preferably, the high friction metal wire 401 is sparser than the common braided stent metal wire 402 .

[0013] Preferably, the metal connecting short rod 5 is S-shaped.

[0014] Preferably, the high friction metal wire 401 is in a spiral shape.

[0015] Furthermore, the common braided stent wire 402 is also in a spiral shape.

[0016] The beneficial effects of the present invention are:

[0017] 1) The stent has different structural and mechanical characteristics in vein segments with different anatomical and kinematic characteristics, and has better targeted adaptability, which can better meet the needs of stent fixation and cross-joint stent placement during iliofemoral vein stent implantation in patients with non-thrombotic iliofemoral vein stenosis and occlusive disease.

[0018] 2) It can ensure that the stent has the characteristics of not affecting the contralateral venous blood flow at the bilateral iliac confluence (low density and petal-shaped design of the proximal petal-shaped stent), enhanced radial support force at the proximal iliac vein (design of the strong radial support stent), strong flexibility across the joint segment (high friction metal wire design of the distal braided stent), high flexibility and strong friction in the distal anchoring area (design of the ordinary braided stent metal wire of the distal braided stent). BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the asymmetric venous stent with increased friction in the anchoring area of ​​the present invention.

[0020] Figure 2 yes Figure 1 A detailed enlarged view of the structural composition of the distal braided stent.

[0021] Figure 3 It is a schematic diagram of an asymmetric venous stent with increased friction in the anchoring area of ​​the present invention being implanted in a human blood vessel.

[0022] Figure 4 It is a schematic diagram of a node between a strong radial support stent and a distal braided stent connected by a short rod.

[0023] In the figure, 1. proximal petal-shaped stent, 2. strong radial support stent, 4. distal braided stent, 401. high friction metal wire, 402. ordinary braided stent metal wire. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] The present invention continues that the ideal venous stent should have the following features:

[0026] 1. The confluence of the bilateral iliac veins needs to ensure smooth blood flow, and stent implantation does not affect the contralateral venous blood flow;

[0027] 2. The stent in the proximal iliac vein anchoring area requires strong radial support force;

[0028] 3. The stent for the vein crossing the joint segment needs to be highly flexible;

[0029] 4. The stent at the distal anchoring area of ​​the external iliac vein needs to maintain high flexibility and increase friction to ensure the stability of the distal anchoring area.

[0030] Therefore, designing and manufacturing an asymmetric stent that does not affect the contralateral venous blood flow at the confluence of the bilateral iliac veins, has strong radial support at the proximal iliac vein, is highly flexible across the joint segment, and has strong friction is of great significance for venous reconstruction in patients with non-thrombotic iliofemoral venous stenosis and occlusive disease.

[0031] See also Figure 1-3 , an asymmetric venous stent with increased friction in the anchoring area, comprising a three-part stent and a group of metal connecting short rods 5; the three parts of the stent are respectively: a proximal petal-shaped stent 1, a strong radial support stent 2, and a distal braided stent 4 connected in sequence from the proximal end to the distal end; the proximal petal-shaped stent 1 is positioned at the confluence of the two iliac veins of the iliac vein, the strong radial support stent 2 is positioned at the easily compressed segment of the common iliac vein, and the distal braided stent 4 is positioned at the distal end of the common iliac vein and the external iliac vein; the radial support force of the three parts of the stent increases in this order: the proximal petal-shaped stent 1 is positioned at the confluence of the two iliac veins of the iliac vein, the strong radial support stent 2 is positioned at the easily compressed segment of the common iliac vein, and the distal braided stent 4 is positioned at the distal end of the common iliac vein and the external iliac vein. Stent 1 < distal braided stent 4 < strong radial support stent 2; the distal braided stent 4 is formed by braiding metal wires, and the expanded diameter of the stent is slightly larger than the target vein diameter but smaller than the strong radial support stent 2; high friction metal wires 401 and ordinary braided stent metal wires 402 are woven into it at the same time, and the expanded diameter and contact area with the blood vessel wall of the high friction metal wires 401 are larger than those of the ordinary braided stent metal wires 402; the group of metal connecting short rods 5 are connected to the strong radial support stent 2 and the braided stent 4 by laser welding, such as Figure 4 As shown, the short rod is in a curved shape. The short rod can also be in a straight line shape (not shown in the drawings).

[0032] The "petal shape" of the proximal petal-shaped stent 1 specifically refers to that the portion of the stent close to the proximal end is in an outwardly opened shape, so it is called a "petal-shaped" stent.

[0033] Continue to see Figure 1-3 ,

[0034] Bi-iliac confluence open design stent 1: including but not limited to open design bare metal stents manufactured by laser engraving technology, materials include but are limited to stainless steel, cobalt-chromium alloy, platinum-chromium alloy, magnesium alloy. The stent has large pores and low metal wire density, and the interference with blood flow is reduced by increasing the pores of the stent and reducing the metal density. The proximal opening of the stent is slightly larger and petal-shaped, ensuring that when both iliac veins are implanted with this design stent, the stents at the confluence of the two iliac veins are staggered, which is not easy to affect the bilateral blood flow (the materials of other bare metal stent parts are the same as above).

[0035] Stent proximal anchoring area strong radial support stent 2: including but not limited to metal bare stents manufactured by laser engraving technology, with large stent expansion diameter (larger than the target vein diameter), thick metal wall, dense metal distribution, and increased radial support of the stent proximal anchoring area by means of large stent expansion diameter, thick metal wall, and high metal coverage. Length 2-4cm, covering the part of the iliac vein that is easily compressed.

[0036] Distal braided stent 4: It is formed by braiding metal wires. The density of the metal wires is low, the expansion diameter of the stent is small (slightly larger than the target vein diameter), and it has high flexibility. The metal wires with high friction are woven in. The expansion diameter and contact area with the blood vessel wall of the metal wire part with high friction are large. The friction of the distal anchoring area of ​​the stent is increased by the large expansion diameter of the stent and the increased contact area with the venous intima surface, and the stimulation of the tube wall caused by the compression of the metal wire of the distal stent is reduced. The length is 4-6cm, covering the cross-joint part of the iliac vein.

[0037] The metal wire 401 with high friction has a larger diameter when expanded, and the contact area between the metal wall of the metal wire and the venous endothelium is increased.

[0038] The common braided stent metal wire 402 has a lower density of the stent metal wire, a smaller stent expansion diameter, and higher flexibility.

[0039] The metal connecting short rod 5 connects the strong radial supporting force stent 2 and the braided stent 4.

[0040] See also Figure 3 , an open-design stent 1 at the confluence of both iliac veins, which extends into the inferior vena cava when implanted; a strong radial support stent 2 in the proximal anchoring area of ​​the stent, which is anchored at the proximal iliac vein; a braided stent 3 in the middle section of the stent, which is the main body of the stent, has high flexibility and covers the main lesion area including the iliac vein cross-joint segment; a braided stent 4 in the distal anchoring area of ​​the stent, which is anchored at the external iliac vein, has high flexibility and strong friction.

[0041] See also Figure 1 The coverage area of ​​the high friction metal wire 401 and the ordinary braided stent metal wire 402 is the same.

[0042] See also Figure 1 and Figure 2 The high friction metal wire 401 is sparser than the ordinary braided stent metal wire 402.

[0043] See also Figure 4 , the metal connecting short rod 5 is in an S shape.

[0044] See also Figure 1 and Figure 2The high friction metal wire 401 is in a spiral shape. The common braided stent metal wire 402 is also in a spiral shape.

[0045] The above are preferred embodiments of the present invention. A person skilled in the art may make various changes or improvements on this basis. Without departing from the general concept of the present invention, these changes or improvements should fall within the scope of protection claimed by the present invention.

Claims

1. An asymmetric venous stent with increased friction in the anchoring area, characterized in that: It includes a three-part bracket and a set of metal connecting short rods (5); The three parts of the stent are, from the proximal end to the distal end, respectively: a proximal petal-shaped stent (1), a strong radial support stent (2), and a distal braided stent (4) connected in sequence; The proximal petal-shaped stent (1) is positioned at the junction of the two iliac veins, the strong radial support stent (2) is positioned at the easily compressed segment of the common iliac vein, and the distal braided stent (4) is positioned at the distal end of the common iliac vein and the external iliac vein; The radial support force of the three-part stent increases in this order: proximal petal-shaped stent (1) < distal braided stent (4) < strong radial support force stent (2); The distal braided stent (4) is formed by braiding metal wires, and the expanded diameter of the stent is slightly larger than the diameter of the target vein but smaller than the strong radial support stent (2); high friction metal wires (401) and ordinary braided stent metal wires (402) are woven into it at the same time, and the expanded diameter and contact area with the blood vessel wall of the high friction metal wires (401) are larger than those of the ordinary braided stent metal wires (402); The group of metal connecting short rods (5) connect the two parts of the strong radial supporting force stent (2) and the braided stent (4) through laser welding, and the short rods can be in a straight line or a curved shape.

2. The asymmetric venous stent with increased friction in the anchoring area according to claim 1, characterized in that: The proximal end of the proximal petal-shaped support (1) is in the shape of a petal that is slightly opened toward the periphery.

3. The asymmetric venous stent with increased friction in the anchoring area according to claim 1, characterized in that: The proximal petal-shaped stent (1) is an open-design bare metal stent manufactured by laser engraving technology; the material includes but is not limited to one of stainless steel, cobalt-chromium alloy, platinum-chromium alloy, and magnesium alloy.

4. The asymmetric venous stent with increased friction in the anchoring area according to claim 3, characterized in that: The strong radial support stent (2) is a bare metal stent manufactured by laser engraving technology. The expanded diameter of the stent is larger than the diameter of the target vein, the metal wall thickness and metal coverage are larger than the distal braided stent (4), and the length is 2-4 cm.

5. The asymmetric venous stent with increased friction in the anchoring area according to claim 1, characterized in that: The distal braided stent (4) is 4-6 cm in length and covers the iliac vein crossing the joint.

6. The asymmetric venous stent with increased friction in the anchoring area according to claim 1, characterized in that: The high friction wire (401) and the common braided stent wire (402) have the same coverage area.

7. The asymmetric venous stent with increased friction in the anchoring area according to claim 6, characterized in that: The high friction metal wire (401) is sparser than the common braided stent metal wire (402).

8. The asymmetric venous stent with increased friction in the anchoring area according to claim 1, characterized in that: The metal connecting short rod (5) is in an S shape.

9. The asymmetric venous stent with increased friction in the anchoring area according to claim 1, characterized in that: The high friction metal wire (401) is in a spiral shape.

10. The asymmetric venous stent with increased friction in the anchoring area according to claim 9, characterized in that: The conventional braided stent wire (402) is also in a spiral shape.

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