Asymmetric vein stent with anchoring zone increasing friction
By designing an asymmetric venous stent with increased friction in the anchoring zone, the problems of stent collapse and insufficient flexibility in existing venous stents for iliofemoral vein stenosis and occlusive diseases were solved, achieving stable stent fixation and unobstructed blood flow, and improving treatment outcomes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI NINTH PEOPLES HOSPITAL SHANGHAI JIAO TONG UNIV SCHOOL OF MEDICINE
- Filing Date
- 2025-04-14
- Publication Date
- 2026-07-14
Smart Images
Figure CN224484248U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a venous stent, and more particularly to an asymmetric venous stent with increased friction in the anchoring area, belonging to the field of vascular stent technology. Background Technology
[0002] Nonthrombotic iliofemoral vein stenosis and occlusive disease is one of the most common and important diseases in venous surgery, significantly affecting patients' limb function and quality of life, and imposing a huge medical and labor burden. With the innovation of endovascular techniques and the development of interventional materials, percutaneous stenting has gradually replaced traditional open bypass surgery and become an important means of clinical treatment for deep vein diseases. It is not only less invasive and has a faster recovery, but also has a patency rate much higher than that of traditional bypass surgery, with an initial patency rate of up to 70% after 3 years.
[0003] Currently, the medical market uses laser-etched venous stents and braided venous stents. Laser-etched stents have uniform compressive strength throughout, often resulting in stent collapse at compressed areas while lacking flexibility in uncompressed areas. Furthermore, stents are prone to angulation at bends in the iliac vein, potentially increasing damage to the intima, causing intimal hyperplasia, and recurrent thrombosis. Braided venous stents offer better flexibility and less damage to the vessel wall, but insufficient radial support can lead to complications such as stent displacement. Summary of the Invention
[0004] The purpose of this invention is to provide an asymmetric venous stent with increased friction in the anchoring zone, which ensures that the stent does not affect the blood flow of the contralateral vein at the biiliac junction, strengthens radial support at the proximal end of the iliac vein, exhibits strong compliance across the joint segment, and has high compliance and strong friction in the distal anchoring zone.
[0005] The present invention adopts the following technical solution:
[0006] An asymmetric venous stent with increased friction in the anchoring zone comprises three stent parts and a set of metal connecting rods 5. The three stent parts, from proximal to distal, are: a proximal stent 1, a high radial support stent 2, and a distal braided stent 4, connected sequentially. The proximal stent 1 is positioned at the biiliac confluence of the iliac veins; the high 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 stent parts increases in the following order: proximal stent 1 < distal braided stent 4. The stent 4 is smaller than the strong radial support stent 2; the distal braided stent 4 is formed by braiding metal wires, and the expansion diameter of the stent is slightly larger than the target vein diameter but smaller than that of the strong radial support stent 2; high-friction metal wire 401 and ordinary braided stent metal wire 402 are simultaneously braided into it, and the expansion diameter and contact area with the vessel wall of the high-friction metal wire 401 are larger than those of the ordinary braided stent metal wire 402; the set of metal connecting short rods 5 connects the strong radial support 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 support 1 is in the shape of a petal that opens slightly outward.
[0008] Preferably, the proximal support 1 is an open-design bare metal support manufactured using laser engraving technology; the material includes, but is not limited to, 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 using laser engraving technology. The stent expansion diameter 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 is 4-6cm in length and covers the iliac vein across the joint.
[0011] Preferably, the high-friction metal wire 401 has the same coverage area as the ordinary braided support metal wire 402.
[0012] Preferably, the high-friction metal wire 401 is sparser than the ordinary braided support metal wire 402.
[0013] Preferably, the metal connecting rod 5 is S-shaped.
[0014] Preferably, the high-friction metal wire 401 is in a spiral shape.
[0015] Furthermore, the ordinary braided support wire 402 is also spiral-shaped.
[0016] The beneficial effects of this utility model are as follows:
[0017] 1) This stent has different structural and mechanical characteristics in different anatomical and biomechanical segments of the vein, and has better targeted adaptability. It can better meet the needs of patients with non-thrombotic iliofemoral vein stenosis and occlusive diseases for stent fixation and cross-joint placement during iliofemoral vein stent implantation.
[0018] 2) It can ensure that the stent has the characteristics of not affecting the blood flow of the contralateral vein at the biiliac junction (low density of the proximal petal-shaped stent and petal design), enhanced radial support force of the proximal iliac vein (design of a stent with strong radial support force), strong compliance across the joint segment (high friction metal wire design of the distal braided stent), and high compliance and strong friction force in the distal anchoring area (design of ordinary braided stent metal wire of the distal braided stent). Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the structure of the asymmetric venous stent with increased friction in the anchoring area of this utility model.
[0020] Figure 2 yes Figure 1 A magnified view showing the detailed structural components of the distal braided stent.
[0021] Figure 3 This is a schematic diagram of the asymmetric venous stent with increased friction in the anchoring area of this utility model being implanted into a human blood vessel.
[0022] Figure 4 This is a schematic diagram of the node connecting the strong radial support bracket and the distal braided bracket via a short rod.
[0023] In the figure, 1. Proximal stent, 2. Strong radial support stent, 4. Distal braided stent, 401. High-friction metal wire, 402. Ordinary braided stent metal wire. Detailed Implementation
[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0025] This invention continues to possess the features that an ideal venous stent should have:
[0026] 1. It is necessary to ensure unobstructed blood flow at the confluence of the two iliac veins, and stent implantation should not affect blood flow in the contralateral vein;
[0027] 2. The stent in the proximal iliac vein anchorage zone requires strong radial support.
[0028] 3. Stents for veins spanning joint segments require high flexibility;
[0029] 4. The stent in the distal anchoring zone of the external iliac vein needs to maintain high flexibility and increase friction to ensure the stability of the distal anchoring zone.
[0030] Therefore, designing and fabricating asymmetrical stents that do not affect blood flow in the contralateral vein at the confluence of the two iliac veins, provide strong radial support to the proximal iliac vein, and have high flexibility and strong friction across the joint segment are of great significance for venous reconstruction in patients with nonthrombotic iliofemoral vein stenosis and occlusive diseases.
[0031] See Figure 1-3 An asymmetric venous stent with increased friction in the anchoring zone includes three stent parts and a set of metal connecting rods 5. The three stent parts, from proximal to distal, are: a proximal stent 1, a high radial support stent 2, and a distal braided stent 4, connected sequentially. The proximal stent 1 is positioned at the biiliac confluence of the iliac veins; the high 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 stent parts increases in the following order: proximal stent 1 < The distal braided stent 4 is smaller than the high radial support stent 2; the distal braided stent 4 is formed by braiding metal wires, and its expansion diameter is slightly larger than the target vein diameter but smaller than that of the high radial support stent 2; it simultaneously incorporates high-friction metal wires 401 and ordinary braided stent metal wires 402, with the expansion diameter and contact area with the vessel wall of the high-friction metal wires 401 being larger than those of the ordinary braided stent metal wires 402; the set of metal connecting rods 5 connects the high radial support stent 2 and the braided stent 4 by laser welding, as shown below. Figure 4 As shown, the short rod has a curved shape. The short rod can also be a straight line (not shown in the attached diagram).
[0032] The "petal shape" of the proximal stent 1 specifically refers to the outward-opening shape of the part of the stent near the proximal end, hence the name "petal-shaped" stent.
[0033] See also Figure 1-3 ,
[0034] Open-design stent at the bilateral iliac confluence 1: This includes, but is not limited to, open-design bare metal stents manufactured using laser engraving technology, with materials including but not limited to stainless steel, cobalt-chromium alloy, platinum-chromium alloy, and magnesium alloy. The stent has relatively large pores and low wire density; by increasing the stent pores and reducing the metal density, interference with blood flow is minimized. The proximal opening of the stent is slightly larger, resembling a petal shape, ensuring that when both iliac veins are implanted with this design, the stents at the bilateral iliac vein confluence are staggered, minimizing impact on bilateral blood flow (the materials of other bare metal stent portions are the same as above).
[0035] Strong radial support stent in the proximal anchoring zone: This includes, but is not limited to, bare metal stents manufactured using laser engraving technology. These stents have a larger expansion diameter (greater than the target vein diameter), thicker metal walls, and denser metal distribution. The radial support in the proximal anchoring zone is increased through this large expansion diameter, thicker metal walls, and higher metal coverage. The length is 2-4 cm, covering areas of the iliac vein prone to compression.
[0036] Distal braided stent 4: Formed from braided metal wires, this stent features low wire density and a small expansion diameter (slightly larger than the target vein diameter), resulting in high flexibility. High-friction wires are incorporated, increasing the expansion diameter and contact area with the vessel wall. This larger expansion diameter and increased intima-media contact area enhance friction in the distal anchoring zone, reducing pressure on the vessel wall caused by the overall wire compression. It is 4-6 cm long and covers the iliac vein at the joint.
[0037] The high-friction metal wire 401 has a larger diameter expansion of the metal wire portion, which increases the contact area between the metal wire wall and the venous intima.
[0038] The standard braided support wire is made of 402, which has a low wire density and a small expansion diameter, resulting in high flexibility.
[0039] The metal connecting rod 5 connects the two parts: the strong radial support bracket 2 and the braided bracket 4.
[0040] See Figure 3 The stent 1 is an open design at the biiliac junction, which extends into the inferior vena cava during implantation; the stent 2 has strong radial support in the proximal anchoring area and is anchored to the proximal end of the iliac vein; the stent 3 is a braided stent in the middle section, which is the main body of the stent and has high flexibility, covering the main lesion area including the joint segment of the iliac vein; the stent 4 is a braided stent in the distal anchoring area and is anchored to the external iliac vein, which has high flexibility and strong friction.
[0041] See Figure 1 The high-friction metal wire 401 has the same coverage area as the ordinary braided support metal wire 402.
[0042] See Figure 1 and Figure 2 The high-friction metal wire 401 is sparser than the ordinary braided support metal wire 402.
[0043] See Figure 4 The metal connecting rod 5 is S-shaped.
[0044] See Figure 1 and Figure 2 The high-friction metal wire 401 is spiral-shaped. The ordinary braided support metal wire 402 is also spiral-shaped.
[0045] The above are preferred embodiments of the present utility model. Those skilled in the art can make various changes or improvements based on this. Without departing from the overall concept of the present utility model, these changes or improvements should all fall within the scope of protection claimed by the present utility model.
Claims
1. An asymmetric venous stent with increased friction in the anchoring zone, characterized in that: It includes a three-part support and a set of metal connecting rods (5); The three-part stent, from proximal to distal, consists of: a proximal stent (1), a strong radial support stent (2), and a distal braided stent (4), connected in sequence. The proximal stent (1) is located at the junction of the two iliac veins, the strong radial support stent (2) is located at the segment of the common iliac vein that is prone to compression, and the distal braided stent (4) is located 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 the following order: proximal stent (1) < distal braided stent (4) < strong radial support stent (2). The distal braided stent (4) is formed by braiding metal wires. The expansion diameter of the stent is slightly larger than the target vein diameter but smaller than that of the strong radial support stent (2). High friction metal wire (401) and ordinary braided stent metal wire (402) are braided into it. The expansion diameter and contact area with the vessel wall of the high friction metal wire (401) are larger than those of the ordinary braided stent metal wire (402). The set of metal connecting short rods (5) are connected by laser welding to two parts: a strong radial support bracket (2) and a braided bracket (4). The short rods can be straight or curved.
2. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 1, characterized in that: The proximal end of the proximal stent (1) is slightly open to the outside.
3. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 1, characterized in that: The proximal stent (1) is an open-design bare metal stent manufactured using laser engraving technology.
4. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 3, characterized in that: The strong radial support stent (2) is a bare metal stent manufactured by laser engraving technology. The stent expansion diameter is greater than the target vein diameter, the metal wall thickness and metal coverage are greater than the distal braided stent (4), and the length is 2-4cm.
5. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 1, characterized in that: The distal braided stent (4) is 4-6 cm long and covers the iliac vein across the joint.
6. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 1, characterized in that: The high-friction metal wire (401) has the same coverage area as the ordinary braided support metal wire (402).
7. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 6, characterized in that: The high-friction metal wire (401) is sparser than the ordinary braided support metal wire (402).
8. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 1, characterized in that: The metal connecting rod (5) is S-shaped.
9. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 1, characterized in that: The high-friction metal wire (401) is spiral-shaped.
10. The asymmetric venous stent with increased friction in the anchoring zone as described in claim 9, characterized in that: The ordinary braided support wire (402) is also spiral-shaped.