A highly compliant drug eluting stent for pulmonary vessels

Abstract

The present application relates to the technical field of medical tools, in particular to a high-compliance drug-eluting stent for pulmonary blood vessels, comprising a tubular stent body, the stent body comprising a distal end section, a middle section and a proximal end section connected in sequence, the distal end section comprising a plurality of first rods arranged in a ring, the distal and proximal ends of each first rod being connected to two adjacent first rods through a first arc-shaped rod and a second arc-shaped rod respectively; the proximal end section comprising a plurality of second rods arranged in a ring, the distal and proximal ends of each second rod being connected to two adjacent second rods through a third arc-shaped rod and a fourth arc-shaped rod respectively; the length of each second rod being greater than that of each first rod; the distal and proximal ends of the middle section being connected to the second arc-shaped rod and the third arc-shaped rod respectively. The present application solves the problem that most of the existing stents for pulmonary blood vessels adopt straight tube structures, which are not conducive to the adhesion of the stents to the inner wall of the pulmonary blood vessels, affect the passage of surgical instruments, and are prone to embolism.

Description

Technical Field

[0001] This invention relates to the field of medical tool technology, and more specifically to a highly flexible drug-eluting stent for pulmonary vessels. Background Technology

[0002] The pulmonary artery, also known as the pulmonary trunk, is the artery that carries venous blood from the heart to the lungs in air-breathing vertebrates. In humans, the pulmonary artery originates from the right ventricle's pulmonary conus and extends below the aortic arch, where it branches into the left and right pulmonary arteries, participating in the transport of venous blood to the lungs. It is a vital pathway in the human pulmonary circulation. In recent years, organic lesions of the pulmonary artery caused by various benign and malignant lesions in the hilum and mediastinum have received increasing attention in clinical practice.

[0003] For pulmonary artery stenosis caused by various etiologies, pulmonary artery stenting can reconstruct an effective channel for the main pulmonary artery and reshape intrapulmonary blood flow perfusion, which is of great significance for improving patients' lung function.

[0004] Due to the complex structure of the pulmonary artery, not only does its radial dimension vary greatly, but its curvature is also quite large. This is mainly because after the pulmonary artery originates from the pulmonary orifice of the right ventricle, it briefly runs through the mediastinum, branching into the left and right pulmonary artery trunks, and then into the pulmonary arteries of each lobe of the two lungs. In this brief path, the curved sections of the vessel run much longer than the straight sections, and the difference in the inner diameter of the vessel is quite large (9-30 mm).

[0005] Currently, most stents used for pulmonary vessels have a straight cylindrical structure. This structure is not conducive to fitting the inner wall of the pulmonary vessels, resulting in the stent not being firmly fixed, affecting the passage of surgical instruments, and easily causing embolism. Summary of the Invention

[0006] The purpose of this invention is to provide a highly flexible drug-eluting stent for pulmonary vessels, which solves the problems of existing stents for pulmonary vessels, most of which use a straight cylindrical structure, which is not conducive to the stent adhering to the inner wall of the pulmonary vessel, affects the passage of surgical instruments, and is prone to embolism.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A highly flexible drug-eluting stent for pulmonary vessels includes a tubular stent body comprising a distal segment, a mid-segment, and a proximal segment connected sequentially. The distal segment includes a plurality of first rods arranged in a ring, with the proximal and distal ends of each first rod connected to two adjacent first rods via first and second arc-shaped rods, respectively. The proximal segment includes a plurality of second rods arranged in a ring, with the proximal and distal ends of each second rod connected to two adjacent second rods via third and fourth arc-shaped rods, respectively. The length of each second rod is greater than the length of the first rod. The proximal and distal ends of the mid-segment are connected to the second and third arc-shaped rods, respectively.

[0008] A further technical solution is that the intermediate segment includes several alternating first intermediate rings and second intermediate rings, with the length of the first intermediate ring being greater than the length of the second intermediate ring.

[0009] A further technical solution is that the first intermediate ring includes third rods arranged in a ring, with the near and far ends of the third rods connected to two adjacent third rods via fifth and sixth arc-shaped rods, respectively; the second intermediate ring includes fourth rods arranged in a ring, with the near and far ends of the fourth rods connected to two adjacent fourth rods via seventh and eighth arc-shaped rods, respectively; at least two fifth arc-shaped rods on two adjacent first intermediate rings and second intermediate rings are connected to the corresponding seventh arc-shaped rods via first connecting rods, or at least two sixth arc-shaped rods are connected to the corresponding eighth arc-shaped rods via second connecting rods.

[0010] A further technical solution is that at least one first connecting rod has a first break joint along its length, the first break joint penetrating the fifth arc-shaped rod and the seventh arc-shaped rod, and at least one second connecting rod has a second break joint along its length, the second break joint penetrating the sixth arc-shaped rod and the eighth arc-shaped rod.

[0011] A further technical solution is that the first, second, third, fourth, fifth, sixth, seventh, and eighth arc-shaped rods are all made of elastic material.

[0012] A further technical solution is that the first, second, third, and fourth rods are all made of elastic material, and the diameters of the third rods include multiple values; the diameters of the fourth rods also include multiple values.

[0013] A further technical solution is that drugs are attached to both the third and fourth rods.

[0014] A further technical solution is that the first rod body has a recessed receiving groove on one side of the first break seam along the length direction. The upper wall of the receiving groove is connected to the outside of the first rod body. A fixing pin is provided in the receiving groove along the length direction. One end of the fixing pin is connected to the groove wall at the far end of the receiving groove, and the other end is set as a sharp part. An elastic element is provided in the receiving groove inside the fixing pin. A limiting strip is provided on the other side of the first break seam along the length direction. The width of the limiting strip gradually decreases from the far end to the near end. When the first break seam is closed, the limiting strip fits against the outside of the fixing pin.

[0015] A further technical solution is that the elastic element is an elastic sheet, one end of which is connected to the far end of the receiving groove, and the other end is slidably attached to the groove wall of the receiving groove, with the middle part of the elastic sheet arched towards the fixing pin.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The lengths of the first and second rods at the distal and proximal ends of the stent body are inconsistent. In clinical practice, the pulmonary artery has a relatively large vascular taper, making it difficult for the proximal end to adhere to the vessel wall, which affects the passage of the device. To solve this clinical pain point, the second rod is lengthened at the proximal end of the stent body. After the stent is released, the proximal end can be expanded again to make the proximal end of the stent close to the shape of the blood vessel and completely adhere to the vessel wall, ensuring the smooth passage of the device in the later stage, and also solving the risk of proximal thrombosis. Attached Figure Description

[0017] Figure 1 This is an overall schematic diagram of a highly flexible drug-eluting stent for pulmonary vessels according to the present invention.

[0018] Figure 2 This is a schematic diagram of the unfolded highly flexible drug-eluting stent for pulmonary vessels according to the present invention.

[0019] Figure 3 for Figure 2 A magnified view of the area marked A in the middle.

[0020] Figure 4 for Figure 2 A magnified view of the area marked B.

[0021] Figure 5 This is a schematic diagram of a partially deployed highly flexible drug-eluting stent for use in pulmonary vessels.

[0022] Figure 6 This is a schematic diagram of the first disconnection seam of the first connecting rod of a highly flexible drug-eluting stent for pulmonary vessels.

[0023] Icons: 1-Distal section, 2-Middle section, 3-Proximal section, 4-First rod body, 5-First arc-shaped rod, 6-Second arc-shaped rod, 7-Second rod body, 8-Third arc-shaped rod, 9-Fourth arc-shaped rod, 10-First connecting block, 11-First stress hole, 12-Second connecting block, 13-Second stress hole, 14-First intermediate ring, 15-Second intermediate ring, 16-Third rod body, 17-Fifth arc-shaped rod, 18-Sixth arc-shaped rod, 19-Fourth rod body, 20-Seventh arc-shaped rod, 21-Eighth arc-shaped rod, 22-First connecting rod, 23-Second connecting rod, 24-First break joint, 25-Second break joint, 26-Receiving groove, 27-Fixing pin, 28-Elastic element, 29-Limiting strip. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. In this application, "distal" refers to the end closer to the lung, and "proximal" refers to the end closer to the thigh. Interventional insertion is performed at the thigh location, inserting a catheter from the thigh into a blood vessel for stent placement.

[0025] Figures 1 to 6 The image shows an embodiment of the present invention.

[0026] Example: A highly flexible drug-eluting stent for pulmonary vessels includes a tubular stent body comprising a distal segment 1, a mid-segment 2, and a proximal segment 3 connected sequentially. The distal segment 1 includes a plurality of first rods 4 arranged in a ring, with the proximal and distal ends of each first rod 4 connected to adjacent first rods 4 via first arc-shaped rods 5 and second arc-shaped rods 6, respectively. The proximal segment 3 includes a plurality of second rods 7 arranged in a ring, with the proximal and distal ends of each second rod 7 connected to adjacent second rods 7 via third arc-shaped rods 8 and fourth arc-shaped rods 9, respectively. The length of each second rod 7 is greater than the length of the first rod 4. The proximal and distal ends of the mid-segment 2 are connected to the second arc-shaped rods 6 and the third arc-shaped rods 8, respectively. The first strut 4 and the second strut 7 at the distal and proximal ends of the stent body are not the same length. In clinical practice, the pulmonary artery has a relatively large vascular taper, making it difficult for the proximal end to adhere to the vessel wall, which affects the passage of the device. To solve this clinical pain point, the second strut 7 is lengthened at the proximal end of the stent body. After the stent is released, the proximal end can be expanded again to make the proximal end of the stent close to the shape of the blood vessel and completely adhere to the vessel wall, ensuring the smooth passage of the device in the later stage, and also solving the risk of proximal thrombosis.

[0027] The intermediate segment 2 includes several alternating first intermediate rings 14 and second intermediate rings 15, wherein the length of the first intermediate ring 14 is greater than the length of the second intermediate ring 15.

[0028] The first intermediate ring 14 includes third rods 16 arranged in a ring, with the proximal and distal ends of each third rod 16 connected to two adjacent third rods 16 via fifth arc-shaped rods 17 and sixth arc-shaped rods 18, respectively. The second intermediate ring 15 includes fourth rods 19 arranged in a ring, with the proximal and distal ends of each fourth rod 19 connected to two adjacent fourth rods 19 via seventh arc-shaped rods 20 and eighth arc-shaped rods 21, respectively. At least two fifth arc-shaped rods 17 on adjacent first intermediate rings 14 and second intermediate rings 15 are connected to the corresponding seventh arc-shaped rods 20 via first connecting rods 22, or at least two sixth arc-shaped rods 18 are connected to the corresponding eighth arc-shaped rods via second connecting rods 23. By using first connecting rods 22 and second connecting rods 23, the number of connection points between the first intermediate rings 14 and second intermediate rings 15 can be controlled. This is beneficial because when the diameters of adjacent first intermediate rings 14 and second intermediate rings 15 at the vascular location increase or decrease, the mutual influence of their expansion degrees can be reduced by decreasing the number of connection points, thus improving the overall flexibility of the stent body.

[0029] At least one first connecting rod 22 has a first discontinuity 24 along its length, the first discontinuity 24 penetrating the fifth arc-shaped rod 17 and the seventh arc-shaped rod 20. At least one second connecting rod 23 has a second discontinuity 25 along its length, the second discontinuity 25 penetrating the sixth arc-shaped rod 18 and the eighth arc-shaped rod 21. By setting the first discontinuity 24 and the second discontinuity 25, both the first intermediate ring 14 and the second intermediate ring 15 are open-loop structures, which can easily change with the shape of the blood vessel and will not cause vasospasm. The distal segment 1 and the proximal segment 3 are closed-loop structures, which enhance the anchoring force of the stent body.

[0030] The first arc-shaped rod 5, the second arc-shaped rod 6, the third arc-shaped rod 8, the fourth arc-shaped rod 9, the fifth arc-shaped rod 17, the sixth arc-shaped rod 18, the seventh arc-shaped rod 20, and the eighth arc-shaped rod 21 are all made of elastic material. When the stent body is released, the inherent elasticity of these rods allows the stent body to rapidly expand and conform to the inner wall of the blood vessel.

[0031] The first rod 4, the second rod 7, the third rod 16, and the fourth rod 19 are all made of elastic material. The diameters of the several third rods 16 and the several fourth rods 19 include multiple values. The diameters of all the third rods 16 are not uniform, but rather a combination of multiple diameters of varying thicknesses. This allows the thicker-diameter third rods 16 to provide support, while the thinner-diameter third rods 16 enhance the flexibility of the support structure. Similarly, the diameters of the fourth rods 19 are not uniform, but rather a combination of multiple diameters of varying thicknesses. This allows the thicker-diameter fourth rods 19 to provide support, while the thinner-diameter fourth rods 19 enhance the flexibility of the support structure.

[0032] Both the third strut 16 and the fourth strut 19 are coated with drugs. Drug-eluting stents, also known as drug-release stents, have drugs carried by polymers on their surface. When the stent is placed in the lesion site within the blood vessel, the drugs are released in a controlled manner into the cardiovascular wall tissue to exert biological effects and prevent in-stent restenosis.

[0033] The first rod 4 has a recessed receiving groove 26 along its length on one side of the first discontinuation slit 24. The upper wall of the receiving groove 26 is connected to the outside of the first rod 4. A fixing pin 27 is provided along its length inside the receiving groove 26. One end of the fixing pin 27 is connected to the distal wall of the receiving groove 26, and the other end is a sharp point. An elastic element 28 is provided inside the fixing pin 27 in the receiving groove 26. A limiting strip 29 is protruding along its length on the other side of the first discontinuation slit 24 on the first rod 4. The width of the limiting strip 29 gradually decreases from the distal end to the proximal end. When the first discontinuation slit 24 is closed, the limiting strip 29 fits against the outer side of the fixing pin 27. In order to further improve the installation firmness of the stent body and avoid the stent body from shifting or loosening during use, this application improves the connection stability between the stent body and the inner wall of the blood vessel by anchoring the fixing pin 27 to the inner wall of the blood vessel when the stent is released. When the stent is released, the first slit 24 separates, and the two sides of the first slit 24 move away from each other, so that the limiting strip 29 moves away from the outside of the fixing needle 27. Thus, the fixing needle 27 will be pushed by the elastic member 28, so that the sharp part of the fixing needle 27 will pass through the outside of the receiving groove 26 and pierce the inner wall of the blood vessel to play an anchoring role.

[0034] The elastic element 28 is an elastic sheet. One end of the elastic sheet is connected to the distal end of the receiving groove 26, and the other end slides against the wall of the receiving groove 26. The middle part of the elastic sheet is arched towards the fixing needle 27. By setting the elastic sheet, the sharp part can be pushed to quickly pass through the receiving groove 26 after the stent body is released and anchored to the inner wall of the blood vessel.

[0035] Although the invention has been described herein with reference to several illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter arrangement within the scope of the disclosure, drawings, and claims. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A highly flexible drug-eluting stent for pulmonary vessels, comprising a tubular stent body, characterized in that, The support body includes a distal segment (1), a middle segment (2), and a proximal segment (3) connected in sequence. The distal segment (1) includes several first rods (4) arranged in a ring. The distal and proximal ends of the first rods (4) are connected to two adjacent first rods (4) through a first arc-shaped rod (5) and a second arc-shaped rod (6), respectively. The proximal segment (3) includes several second rods (7) arranged in a ring. The distal and proximal ends of the second rods (7) are connected to two adjacent second rods (7) through a third arc-shaped rod (8) and a fourth arc-shaped rod (9), respectively. The length of the second rods (7) is greater than the length of the first rods (4). The distal and proximal ends of the middle segment (2) are connected to the second arc-shaped rod (6) and the third arc-shaped rod (8), respectively.

2. The highly flexible drug-eluting stent for pulmonary vessels according to claim 1, characterized in that: The intermediate segment (2) includes several alternating first intermediate rings (14) and second intermediate rings (15), wherein the length of the first intermediate ring (14) is greater than the length of the second intermediate ring (15).

3. The highly flexible drug-eluting stent for pulmonary vessels according to claim 2, characterized in that: The first intermediate ring (14) includes a third rod (16) arranged in a ring shape. The near and far ends of the third rod (16) are connected to two adjacent third rods (16) through a fifth arc rod (17) and a sixth arc rod (18), respectively. The second intermediate ring (15) includes a fourth rod (19) arranged in a ring shape. The near and far ends of the fourth rod (19) are connected to two adjacent fourth rods (19) through a seventh arc rod (20) and an eighth arc rod (21), respectively. At least two of the fifth arc rods (17) on the two adjacent first intermediate rings (14) and second intermediate rings (15) are connected to the corresponding seventh arc rods (20) through a first connecting rod (22), or at least two of the sixth arc rods (18) are connected to the corresponding eighth arc rods through a second connecting rod (23).

4. The highly flexible drug-eluting stent for pulmonary vessels according to claim 3, characterized in that: At least one of the first connecting rods (22) is provided with a first break seam (24) along the length direction, the first break seam (24) penetrates the fifth arc-shaped rod (17) and the seventh arc-shaped rod (20), and at least one of the second connecting rods (23) is provided with a second break seam (25) along the length direction, the second break seam (25) penetrates the sixth arc-shaped rod (18) and the eighth arc-shaped rod (21).

5. A highly flexible drug-eluting stent for pulmonary vessels according to claim 4, characterized in that: The first arc-shaped rod (5), the second arc-shaped rod (6), the third arc-shaped rod (8), the fourth arc-shaped rod (9), the fifth arc-shaped rod (17), the sixth arc-shaped rod (18), the seventh arc-shaped rod (20), and the eighth arc-shaped rod (21) are all made of elastic material.

6. A highly flexible drug-eluting stent for pulmonary vessels according to claim 4, characterized in that: The first rod (4), the second rod (7), the third rod (16) and the fourth rod (19) are all made of elastic material. The diameters of the third rod (16) include multiple values; the diameters of the fourth rod (19) include multiple values.

7. A highly flexible drug-eluting stent for pulmonary vessels according to claim 4, characterized in that: Both the third rod (16) and the fourth rod (19) are coated with drugs.

8. A highly flexible drug-eluting stent for pulmonary vessels according to claim 4, characterized in that: The first rod (4) has a recessed receiving groove (26) along the length direction on one side of the first break seam (24). The upper groove wall of the receiving groove (26) is connected to the outside of the first rod (4). A fixing pin (27) is provided in the receiving groove (26) along the length direction. One end of the fixing pin (27) is connected to the groove wall at the far end of the receiving groove (26), and the other end is set as a sharp part. An elastic element (28) is provided on the inner side of the fixing pin (27) in the receiving groove (26). A limiting strip (29) is provided on the other side of the first rod (4) along the length direction. The width of the limiting strip (29) gradually decreases from the far end to the near end. When the first break seam (24) is closed, the limiting strip (29) fits against the outside of the fixing pin (27).

9. A highly flexible drug-eluting stent for pulmonary vessels according to claim 8, characterized in that: The elastic element (28) is an elastic sheet. One end of the elastic sheet is connected to the far end of the receiving groove (26), and the other end slides against the groove wall of the receiving groove (26). The middle part of the elastic sheet is arched towards the fixing pin (27).

Images