Covered stent and stent system
By designing the main stent and branch stent structure of the coated stent, the problem of difficulty in selecting guidewires and winding in traditional coated stents is solved, and the direct delivery and release of branch stents is achieved, reducing the risk and time of surgery.
Patent Information
- Application Number
- CN202311870375.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-28
- Publication Date
- 2025-07-01
Smart Images
Figure CN120227197A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a covered stent and a stent system. Background Art
[0002] Aortic aneurysms and aortic dissections are currently diseases that seriously endanger human life safety. If not actively treated, the aortic aneurysm and dissection will continue to grow and finally rupture, causing serious complications and even leading to the death of the patient. With the continuous increase in the number of patients with hypertension, hyperlipidemia, and hyperglycemia, the current incidence of aortic aneurysms and aortic dissections is also increasing significantly.
[0003] Traditional open surgical treatment of aortic aneurysms and aortic dissections involving branch vessels has the disadvantages of large trauma, high mortality, long operation time, high incidence of postoperative complications, and high operation difficulty. Endovascular treatment, on the other hand, has the characteristics of small trauma, few postoperative complications, short operation time, and low operation difficulty, and has gradually become the main method for treating aortic aneurysms and aortic dissections. By implanting a covered stent in the aorta, the vascular lesion is isolated outside the covered stent, and the blood flow is restricted to flow through the inside of the covered stent, thereby achieving the purpose of protecting the blood vessel. In traditional aortic covered stents, generally, after the main body part is released along the main guide wire selected into the main lumen, the branch guide wire is prefabricated to select the branch on the aortic arch. It is easy for the two guide wires to become entangled. Moreover, when the branch guide wire selects the branch on the aortic arch, a snare on the upper limb approach is needed to snare the branch guide wire, so as to snare the branch guide wire into the branch on the aortic arch to complete the selection of the branch on the aortic arch. During the operation, the selection of the branch guide wire is difficult, which will prolong the operation time and increase the operation risk. Summary of the Invention
[0004] A technical problem solved by the present invention is how to set the structure of the covered stent to reduce the number of guide wire selections while ensuring the release of the proximal end of the main stent on the premise that the branch stent can be directly delivered to and released in the branch vessel.
[0005] The present invention provides a covered stent, which includes a main stent and a branch stent. The main stent includes a first side and a second side. The main stent includes a branch opening provided on the first side. The first end of the branch stent is connected to the branch opening. The main stent includes a first section extending from the branch opening towards the proximal end. The first section is provided with a first semi-restraining structure. The branch stent is provided with a second semi-restraining structure. Define the length of the branch stent along its axial direction as L1, and define the length of the first section along its axial direction as L2. The L1 and L2 satisfy: L1 > L2.
[0006] In one embodiment, the main stent further includes a second section extending from the branch opening towards the distal end. The part of the second section close to the first section is also provided with the first semi-restraining structure.
[0007] In one embodiment, a first developing member is disposed at a proximal end of the second section.
[0008] In one embodiment, the second section includes a first wave ring, the first wave ring is arranged on the proximal end side of the second section, the first wave ring includes a plurality of wave rods, and the distal end of the first developing member does not exceed the midpoint of any wave rod in the axial direction.
[0009] In one embodiment, the first wave coil includes a wave crest near the proximal end, and the first developing member includes a developing wire wound along the wave crest of the first wave coil;
[0010] Alternatively, the first section includes a second wave circle, the second wave circle is close to the second section, and the first developing member is sewn on the coating between the first wave circle and the second wave circle.
[0011] In one embodiment, the axial length of the first section is smaller than its diameter in its natural state.
[0012] In one embodiment, the ratio of the diameter of the circumscribed circle of the cross section of the first section when in a semi-constrained state to the diameter of the circumscribed circle of the cross section of the first section when the main stent is naturally expanded is 0.14 to 0.4.
[0013] The present invention also provides a stent system, which includes a delivery device such as the above-mentioned coated stent, the delivery device includes a sheath-core assembly, a sheath tube, a first binding wire and a second binding wire, the branch stent includes a free end opposite to the first end, when the coated stent is compressed in the sheath tube, the sheath-core assembly penetrates from the distal end of the main stent to the free end of the branch stent, the first binding wire passes through the first semi-binding structure in sequence along the axial direction, the branch stent is folded in the axial direction of the main stent toward the proximal end of the first section, the second binding wire passes through the second semi-binding structure along the axial direction, and the branch stent and the main stent are radially compressed in the sheath tube.
[0014] In one embodiment, the first binding wire comprises a pre-bent portion and a straight portion connected to each other, the pre-bent portion is arranged at the distal end of the first binding wire, and the pre-bent angle of the pre-bent portion relative to the straight portion is greater than 20°;
[0015] Alternatively, the support system also includes a pre-bent rod with a distal pre-bend, the pre-bent rod including a pre-bent portion and a straight portion that are connected to each other, the pre-bent portion is arranged on the distal side of the pre-bent rod, the pre-bent angle of the pre-bent portion relative to the straight portion is greater than 20°, and the pre-bent portion is correspondingly arranged at the first section of the main support.
[0016] The present invention further provides a stent system. The stent system includes a delivery device such as the above-mentioned covered stent. The delivery device includes a sheath-core assembly, a sheath tube, a first binding wire, and a second binding wire. The branch stent includes a free end opposite to the first end. When the covered stent is compressed in the sheath tube, the sheath-core assembly penetrates from the distal end of the main stent to the free end of the branch stent and exits. The first binding wire sequentially penetrates through the first half-binding structure along the axial direction. The branch stent is folded in the axial direction of the main stent towards the proximal end of the first section. The second binding wire axially penetrates through the second half-binding structure, and the branch stent and the main stent are radially compressed in the sheath tube. A second imaging element is provided at the distal end of the sheath tube.
[0017] A technical effect of an embodiment of the present invention is to provide a covered stent to reduce the number of guide wires selected while ensuring the release of the proximal end of the main stent on the premise of directly delivering the branch stent to the branch blood vessel and releasing it.
[0018] Thus, the stent system provided by the present invention can directly select the guide wire into the branch above the aortic arch, reducing the number of guide wires selected, avoiding the entanglement problem between the two guide wires caused by the need to prefabricate the branch guide wire and the main guide wire in the prior art, and also avoiding the problem that the prefabricated guide wire is not easy to select, reducing the overall operation time and lowering the operation risk. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a schematic structural diagram of a covered stent provided by the present invention;
[0020] Figure 2 is Figure 1 an enlarged view of the second wave loop in
[0021] Figure 3 is a schematic structural diagram of another covered stent provided by the present invention;
[0022] Figure 4 is Figure 3 an enlarged view of the first wave loop in
[0023] Figure 5 is Figure 3 a schematic structural diagram of the covered stent provided by
[0024] Figure 6 is Figure 5 a schematic structural diagram of a partial stent system formed by penetrating the sheath-core assembly from the distal end of the main stent to the free end of the branch stent on the basis of
[0025] Figure 7 is Figure 6 a schematic structural diagram of the structure formed by inserting the covered stent into the sheath tube on the basis of
[0026] Figure 8 Schematic diagram of a first binding wire or pre-bent rod provided by the present invention;
[0027] Figure 8a For Figure 8 marked illustration;
[0028] Figure 8b Schematic diagram of the pre-bent part of the first binding wire or pre-bent rod provided by the present invention pressing against the first segment of bending in a semi-bound state (relative to Figure 5 );
[0029] Figure 9 Schematic diagram of when the stent system provided by the present invention is input into the aortic arch, and the branch guide wire is selected from the femoral artery into the left subclavian branch artery;
[0030] Figure 10 For the stent system provided by the present invention along Figure 9 The delivery channel constructed by the branch guide wire in the figure conveys the covered stent to the aortic arch, sends part of the branch stent into the left subclavian branch artery, finely adjusts the stent system along the branch guide wire so that the proximal end of the main stent is located at the mouth of the left subclavian branch artery, and then withdraws the sheath tube so that the first segment of the main stent is exposed outside the sheath tube;
[0031] Figure 11 For on the basis of Figure 10 in the figure, continue to convey the branch stent along the branch guide wire into the branch blood vessel, and at the same time convey the first end of the branch stent to the mouth of the left subclavian branch artery;
[0032] Figure 12 Schematic diagram of withdrawing the sheath tube to the distal end of the main stent so that the main stent in a semi-bound state is completely exposed outside the sheath tube;
[0033] Figure 13 For on the basis of Figure 12 in the figure, withdraw the second binding wire and the first binding wire in sequence, so that the branch stent and the main stent are released from the semi-bound state and completely released to the natural expansion state, and then withdraw the delivery device to complete the release of the covered stent;
[0034] 100. Covered stent; 10. Main stent; 101. First side; 102. Second side; 103. Branch opening; 11. First bare wave ring; 12. Main wave ring; 13. Main stent covering; 10a. First segment; 122. Second wave ring; 10b. Second segment; 121. First wave ring; 1212. Wave rod; 14. First semi-binding structure; 141. Binding diameter line; 142. Locking component; 1421. First lock; 1422. Second lock; 143. Limit loop; 144. Limiting member;
[0035] 15. The first developing member;
[0036] 20. Branch bracket;
[0037] 21. The second semi-binding structure; 22. Connecting section; 23. Extension section; 24. Transition section;
[0038] 70. Delivery device; 71. Sheath core assembly; 711. Sheath core; 712. Guide head; 72. Sheath tube; 721. The second developing member; 73. The first binding wire; 731. Straight portion; 732. Pre-bent portion; 733. Refinement portion; 74. The second binding wire;
[0039] 75. Pre-bent rod;
[0040] 901. Left subclavian branch artery; 900a. Major curvature side of blood vessel; 900b. Minor curvature side of blood vessel; 902. Branch guide wire Detailed implementation manner
[0041] For the convenience of understanding the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.
[0042] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "inner", "outer", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.
[0043] "Axial direction" generally refers to the length direction of the medical device when it is being delivered, and "radial direction" generally refers to the direction perpendicular to its "axial direction" of the medical device, and the "axial direction" and "radial direction" of any component of the medical device are defined based on this principle. In addition, when describing a lumen stent or a covered stent, the orientation can be defined according to the blood flow direction in the blood vessel. In the present invention, it is defined that the blood flow flows from the proximal end to the distal end of the stent.
[0044] In the field of interventional medical devices, generally for a delivery device that delivers a medical device when implanting the medical device into the human body or animal body, the end closer to the operator is called the "proximal end", and the end farther from the operator is called the "distal end", and the "proximal end" and "distal end" of any component of the delivery device are defined based on this principle.
[0045] The present invention provides a covered stent 100, such asFigure 1-2 As shown, the covered stent 100 includes a main stent 10 and a branch stent 20. The main stent 10 is a tubular structure with openings at both ends, including a first bare coil 11, main coils 12, and a main covering 13. Among them, there are multiple main coils 12, and the multiple main coils 12 are arranged axially and connected by the tubular main covering 13; the first bare coil 11 is arranged on the proximal side of the main coils 12 and is connected to the proximal edge of the main covering 13; in other embodiments, the first bare coil may not be provided. At this time, the proximal end of the covering 13 is the proximal end of the main stent.
[0046] The axial length range of the main stent 10 is: 40 mm to 240 mm. Different specifications of covered stents can be set according to the different axial lengths of the main stent 10. Specifically, different specifications of covered stents can be selected according to the degree of aortic aneurysm involvement.
[0047] In this embodiment, the main coils 12 are arranged outside the main covering 13. When implanted into the blood vessel, it can enhance the friction between the main stent 10 and the inner wall of the blood vessel, which is beneficial to preventing the main stent 10 from shifting or shortening relative to the inner wall of the blood vessel. In other embodiments, the main coils 12 can also be arranged inside the main covering 13, or part of the main coils 12 are arranged inside the main covering 13 and part are arranged outside the main covering 13, which is not limited here.
[0048] The main stent 10 includes a first side 101 and a second side 102. When the covered stent 100 is in the implanted state and the branch stent 20 faces the branch of the aortic arch, the first side 101 is the side of the main stent 10 close to the branch of the aortic arch (the large curvature side of the blood vessel) when the covered stent 100 is implanted into the blood vessel, and the second side 102 is the side of the main stent 10 far from the branch of the aortic arch (the small curvature side of the blood vessel) when the covered stent 100 is implanted into the blood vessel. The first side 101 and the second side 102 each occupy an arc of 180° of the circumference, and the branch stent 20 can be arranged at the middle position of the arc of the first side 101, as Figure 1 shown.
[0049] In this embodiment, the main stent 10 includes a first section 10a, a second section 10b, and a branch opening 103 arranged on the first side 101. The first section 10a and the second section 10b are each part of the main stent 10 in the axial direction. Taking the center of the branch opening 103 as the boundary, the first section 10a extends from the branch opening 103 towards its proximal end, and the second section 10b extends from the branch opening 103 towards its distal end. Among them, the first section 10a is provided with a first semi-binding structure 14, and the branch stent 20 is provided with a second semi-binding structure 21; define the axial length of the branch stent 20 as L1, define the axial length of the first section 10a as L2, and L1 and L2 satisfy: L1 > L2, as Figure 1As shown, the length range of L2 can be selected as: 10 mm to 40 mm.
[0050] As Figure 1 and Figure 3 As shown, the branch stent 20 includes a connecting section 22 and an extension section 23. The connecting section 22 connects the extension section 23 to the main stent 10. The outer diameter of the extension section 23 is greater than that of the connecting section 22. A transition section 24 is further included between the extension section 23 and the connecting section 22. The outer diameter of the transition section 24 gradually increases in the direction from the connecting section 22 to the extension section 23. The outer diameter range of the branch stent 20 can be set as: 6 mm to 20 mm. In other embodiments, the branch stent 20 can also be set as an equal-diameter extended stent structure, which is not limited herein.
[0051] In this embodiment, the first semi-restraining structure 14 can be provided only on the wave loops located in the first section 10a. The second section 10b includes a first wave loop 121 provided on the proximal side of the second section 10b; the first section 10a includes a second wave loop 122. The second wave loop 122 is located at a position where the first section 10a is close to the second section 10b. In order to indicate the retraction position of the sheath 72, a first imaging member 15 is provided at the proximal end of the second section 10b. The first imaging member 15 can be provided on the membrane, such as Figure 1 As shown, the first imaging member 15 can be sutured to the membrane between the first wave loop 121 and the second wave loop 122, as long as the position between the first wave loop 121 and the second wave loop 122 can be indicated.
[0052] The first imaging member 15 can also be provided on the first wave loop 121, such as Figure 3-4 As shown, the first wave loop 121 includes a wave crest 1211 close to the proximal end. The first imaging member 15 includes a developing wire wound along the wave crest of the first wave loop 121, such as Figure 3-4 As shown. The first wave loop 121 includes a plurality of wave rods 1212. The distal end of the first imaging member 15 does not axially exceed the midpoint of any wave rod 1212 in the circumferential direction of the first wave loop 121. In order to indicate the retractable position of the distal end of the sheath 72 when the first section 10a is released from the sheath 72, it can prevent the first wave loop 121 at the proximal end of the second section 10b from jumping out of the sheath 72 before the membrane stent 100 is delivered to the predetermined release position due to excessive retraction of the sheath 72.
[0053] The first half-binding structure 14 may also be provided on all the corrugations (the main body corrugations 12 and the first bare corrugation 11) in the axial direction of the main body bracket 10. Alternatively, the first half-binding structure 14 may be provided on the corrugations located in the first section 10a and the part of the second section 10b close to the first section 10a, that is, the first half-binding structure 14 is provided on the corrugations in the first section 10a and the first corrugation 121, and the half-binding structure is provided on the first corrugation 121 in the second section 10b. This can prevent the proximal end of the first corrugation 121 in the second section 10b from jumping out of the sheath tube 72 when the sheath tube 72 withdraws and releases the first section 10a from the sheath tube 72 due to excessive withdrawal of the sheath tube 72.
[0054] As Figure 1 and Figure 3 shown, the branch bracket 20 includes a first end and a free end opposite to the first end, and the first end of the branch bracket 20 is connected to the branch opening 103 of the main body bracket 10. The branch bracket 20 has a tubular structure with openings at both ends, and the axial direction of the branch bracket 20 is along the axial direction of its tubular structure. In the natural state of the covered stent 100, since there is a certain angle (the angle range can be set at: 70° to 90°) between the axial direction of the tubular structure of the branch bracket 20 and the axial direction of the tubular structure of the main body bracket 10; when the main body bracket 10 is a straight tube, the axial direction of the tubular structure of the main body bracket 10 is along the extending direction of the main body bracket 10, and when the main body bracket 10 is a bent tube, the axial direction of the tubular structure of the main body bracket 10 is along the extending direction of the main body bracket 10. This angle is the angle between the tangent line at the branch opening 103 on the main body bracket 10 and the axial line of the branch bracket 20. Figure 1 Taking the covered stent 100 with the main body bracket 10 being a straight tube stent and this angle being 90° as an example, in the natural state of the covered stent 100, the axial direction of the branch bracket 20 is different from the axial direction of the main body bracket 10.
[0055] As Figure 1-2 shown, in this embodiment, the first half-binding structure 14 and the second half-binding structure 21 may be set to the same beam diameter structure. The first half-binding structure 14 or the second half-binding structure 21 includes a beam diameter line 141, a locking component 142, a limiting ring buckle 143, and a limiting member 144. The beam diameter line 141 passes through a plurality of limiting ring buckles 143 along the circumferential direction of the main body bracket 10, thereby limiting the beam diameter line 141 to the middle position of the main body corrugation 12. The locking component 142 is connected to the beam diameter line 141 and is formed at both ends of the beam diameter line 141. In this embodiment, the beam diameter line 141 is a double-strand line, and the locking component 142 is the folded end of the beam diameter line 141. In other embodiments, the beam diameter line 141 may also be two sections of double-strand lines, which is not limited herein. As long as the beam diameter line 141 is limited to the middle position of the wave rod of the main body corrugation 12 by the limiting ring buckle 143, the beam diameter line 141 can bind the corrugation more stably.
[0056] The limiting ring buckle 143 is circumferentially arranged on the main body bracket 10 (branch bracket 20), and can be fixed on the main body corrugated ring 12 or the main body film 13. In this embodiment, a plurality of limiting ring buckles 143 are circumferentially and spacedly fixed in the middle of some wave rods of the main body corrugated ring 12. Each beam diameter line 141 sequentially passes through a plurality of limiting ring buckles 143 on the corresponding main body corrugated ring 12 in the circumferential direction, so that the limiting ring buckle 143 confines the beam diameter line 141 at the middle area in the axial direction of the main body corrugated ring 12, which can prevent the main body corrugated ring 12 from being unevenly stressed when radially constrained by the beam diameter line 141, thereby facilitating the circumferential constraint of the first half-binding structure 14 (second binding structure) on the first section 10a (branch bracket 20).
[0057] The buckle assembly 142 includes a first buckle 1421 and a second buckle 1422 connected to both ends of the beam warp thread. Both the first buckle 1421 and the second buckle 1422 are annular ends formed by folding back the beam diameter line 141. After the first section 10a (branch bracket 20) of the film-covered bracket 100 is radially compressed and the film-covered bracket 100 is in the natural state, the limiting member 144 is arranged in the middle of the area not crossed by the beam diameter line 141, and can be directly sutured on the film or sutured on the film by bypassing the wave rod. And the limiting members 144 are axially spaced on the main body bracket 10 and are circumferentially corresponding to the positions where the first binding structure is arranged on the main body bracket 10. During the process of radially compressing the film-covered bracket 100 from the natural state to the semi-binding state, first pass the first buckle 1421 through the limiting member 144 on its corresponding wave ring, and the first binding wire 73 of the conveying device 70 axially passes through the first buckle 1421 to limit the first buckle 1421 at the position of the limiting member 144. The first binding wire 73 also needs to pass through the second buckle 1422 corresponding in the same circumference. After the first section 10a and the branch bracket 20 are respectively beam-diametered to the semi-binding state, before loading the film-covered bracket 100 into the sheath, the branch bracket 20 can be folded towards the direction of the first section 10a, and then the film-covered bracket 100 is radially compressed as a whole in the sheath tube 72, as shown in Figure 5-7 shown.
[0058] The present invention also provides a stent system, which further includes the above-mentioned film-covered bracket 100, and also includes a conveying device 70. The conveying device 70 includes a sheath core assembly 71, a sheath tube 72, a first binding wire 73 and a second binding wire 74. Among them, the sheath core assembly 71 includes a sheath core 711 and a guiding head 712, and the guiding head 712 is connected to the distal end of the sheath core 711 to guide the conveying device 70 to be conveyed to a predetermined position.
[0059] The process of loading the above-mentioned film-covered bracket 100 into the sheath tube 72 is as follows:
[0060] The first binding wire 73 axially passes through the first semi-binding structure 14 from the distal end to the proximal end of the main body stent 10 in sequence, such that the first section 10a is in a semi-bound state; the second binding wire 74 axially passes through the second semi-binding structure 21 from the first end to the free end of the branch stent 20 along its axial direction in sequence, such that the branch stent 20 is also in its semi-released state, as Figure 5 shown; then the branch stent 20 is folded in the axial direction of the main body stent 10 towards the direction of the first section 10a. Meanwhile, when the covered stent is compressed in the sheath, the sheath core assembly 71 penetrates into the main body stent 10 from the distal end and penetrates out from the free end of the branch stent 20. At this time, the covered stent 100 surrounds the sheath core assembly 71, and both the first section 10a of the main body stent 10 and the branch stent 20 as a whole are in a semi-bound state of radial compression, as Figure 6 shown; then the branch stent 20 and the main body stent 10 are further radially compressed within the sheath 72, as Figure 7 shown.
[0061] In this embodiment, as Figure 8-8b shown, the first binding wire 73 sequentially includes a straight portion 731, a pre-bent portion 732, and a refined portion 733 along the axial direction from the proximal end to the distal end. The pre-bent portion 732 and the refined portion 733 are disposed on the distal side of the first binding wire 73, and the distal end of the pre-bent portion 732 is connected to the refined portion 733, and the proximal end of the pre-bent portion 732 is connected to the straight portion 731, such that the pre-bent portion 732 is disposed between the refined portion 733 and the straight portion 731. The refined portion 733 is refined relative to the pre-bent portion 732 (refinement can be achieved by methods such as electrochemical corrosion using a polishing solution), such that the wire diameter of the refined portion 733 is smaller than the wire diameters of the pre-bent portion 732 and the straight portion 731, making the refined portion 733 as a whole soft. The refined portion 733 is disposed at the most distal end of the first binding wire 73, and when the distal end of the first binding wire 73 is exposed in the blood vessel, it can prevent it from puncturing the inner wall of the blood vessel.
[0062] Wherein, the pre-bending angle α of the pre-bent portion 732 relative to the straight portion 731 is greater than or equal to 20°. Define the straight line where the proximal end point A and the distal end point B of the pre-bent portion 732 are located as L3, and the ray where the straight portion 731 extends towards the distal end from the proximal end point of the pre-bent portion 732 as L4. The included angle between the straight line L3 and the ray L4 is the pre-bending angle α. In other embodiments, the pre-bending angle α satisfies: 20° ≤ α ≤ 70°. Wherein, the pre-bent portion 732 is correspondingly disposed at the first section of the covered stent. Therefore, the projection length of the line segment AB between the proximal end point A and the distal end point B of the pre-bent portion 732 on the ray L4 is approximately equal to the length of the first section.
[0063] As Figure 8a-8bAs shown, the pre-bending portion 732 is arc-shaped. The pre-bending portion 732 bends and extends towards the distal end from its proximal end point A (the connection point of the pre-bending portion 732 and the straight portion 731), and gradually moves away from the ray L4 along which the straight portion 731 extends towards the distal end. The pre-bending portion 732 is correspondingly arranged at the first section 10a of the main body stent 10. The straight portion 731 corresponds to the second section 10b of the main body stent 10 and extends along the axis of the second section 10b, so as to ensure that in the semi-bound state, the first section 10a released from the sheath 72 is more bent towards the second side 102 relative to the branch stent 20 than the first section 10a of the main body stent 10 in the natural state. This can enable the first section 10a to bend away from the major curvature side of the blood vessel and towards the minor curvature side during the delivery of the covered stent 100, thereby preventing the proximal end of the main body stent 10 from piercing the major curvature side 900a of the blood vessel. In other embodiments, the first binding wire 73 can also be only used to bind the first section 10a to the semi-bound state. Additionally, a pre-bending rod 75 is provided. The pre-bending rod 75 sequentially includes a straight portion 731, a pre-bending portion 732, and a refining portion 733 along the axis from the proximal end to the distal end. The specific settings of the straight portion 731, the pre-bending portion 732, and the refining portion 733 of the pre-bending rod 75 are the same as above and will not be elaborated here. And the pre-bending angle α of the pre-bending portion 732 relative to the straight portion 731 is greater than or equal to 20°. Wherein, the pre-bending rod 75 passes through the inner cavity of the main body stent 10, and the pre-bending portion 732 is correspondingly arranged at the first section 10a of the main body stent 10, so as to ensure that when the first section 10a in the semi-released state is released from the sheath 72, it is more bent towards the second side 102 relative to the branch stent 20 than the first section 10a of the main body stent 10 in the natural state. This can enable the first section 10a to bend away from the major curvature side and towards the minor curvature side during the delivery of the covered stent 100, thereby preventing the proximal end of the main body stent 10 from piercing the major curvature side 900a of the blood vessel.
[0064] The pre-bending portion 732 can be arranged inside or outside the cavity of the first side 101 of the first section 10a, or can be arranged inside or outside the cavity of the second side 102. When the pre-bending portion 732 is arranged inside or outside the cavity of the first side 101, the pre-bending portion 732 can be arranged on the first binding wire 73. The first binding wire 73 extends axially along the first side 101 of the main body stent 10 and is staggered from the second binding wire 74 (the second binding wire 74 can extend along the center line of the first side 101) (that is, the first binding wire 73 axially avoids the branch stent 20); alternatively, a pre-bending rod 75 can be additionally provided, and at the same time, the pre-bending rod 75 extends axially along the first side 101 of the main body stent 10 and is circumferentially staggered from the first binding wire 73 and the second binding wire 74.
[0065] Since the pre-bent portion 732 is provided to enable the first section 10a to bend toward the minor curvature side 900b of the blood vessel and away from the major curvature side 900a of the blood vessel when the first section 10a is released from the sheath 72 during the delivery of the covered stent 100, that is, it is necessary to drive the first section 10a to bend toward the minor curvature side by means of the pre-bent portion 732 during the delivery process when the first section 10a is exposed from the sheath 72. When the pre-bent portion 732 is disposed inside or outside the cavity of the second side 102, if the binding degree of the first half-binding structure 14 is not large (that is, the radial compression of the first section 10a in the semi-bound state is less), then the change in the diameter of the circumscribed circle of the cross section of the first section 10a in the semi-bound state relative to the diameter of the circumscribed circle of the cross section when it is naturally expanded is not large. Then, the first section 10a unfolds too much in the semi-bound state, resulting in too many lumen openings in the first section 10a, a relatively large distance between the corresponding first side 101 and the second side 102, and a hollow center in the lumen. It is very difficult to drive the wave loops on the first side 101 to bend toward the minor curvature side along with the pre-bent portion 732 by disposing the pre-bent portion 732 on the second side 102, and thus the first side 101 of the first section 10a is far from the major curvature side 900a of the blood vessel. The first half-binding structure 14 makes the first section 10a or the entire main stent 10 in a semi-bound state, and the second half-binding structure 21 makes the branch stent 20 in a semi-released state. According to the different degrees of binding, when the first section 10a is in a semi-bound state, its radial compression is similar to that of a tubular cavity or a tightly held cylinder. The ratio of the diameter of the circumscribed circle of the cross section of the first section 10a in the semi-bound state to the diameter of the circumscribed circle of the cross section of the first section 10a when the main stent 10 is naturally expanded is: 0.14 to 0.4( Figure 5 An example where the ratio is 0.15 is shown in the figure); when the ratio is relatively large, since the pre-bent portion 732 is disposed on the second side 102, there are too many lumen openings in the first section 10a in the semi-bound state, and the first section is a tubular cavity with a hollow center in the lumen. It is very difficult to drive the wave loops on the first side 101 to bend toward the minor curvature side along with the pre-bent portion 732 by disposing the pre-bent portion 732 on the second side 102; when the ratio is set within the above range, the first section 10a in the semi-bound state is radially compressed similar to a tightly held cylinder. At this time, the first side 101 and the second side 102 of the first section 10a are tightly held and can be regarded as an integral part. Therefore, the pre-bent portion 732 can be used to drive the tightly held first section 10a to bend toward the minor curvature side 900b of the blood vessel, thereby driving the first side 101 away from the major curvature side 900a of the blood vessel. When the pre-bent portion 732 is disposed inside or outside the cavity of the first side 101, the ratio of the diameter of the circumscribed circle of the cross section of the first section 10a in the semi-bound state to the diameter of the circumscribed circle of the cross section of the first section 10a when the main stent 10 is naturally expanded can also be: 0.14 to 0.4, which can prevent the first section 10a in the semi-bound state from being loose, so that when the first section 10a is in the semi-bound state, the pre-bent portion 732 can drive the first section 10a to have a better pre-bending effect.
[0066] In other embodiments, in order to further prevent the first section 10a of the main stent 10 from piercing the inner wall of the small curvature side 900b of the blood vessel during the delivery process of the covered stent 100, the axial length of the first section 10a can also be set to be less than its diameter in the natural state. As Figure 1 shown, in the natural state of the main stent 10, the lumen diameter of the first section 10a is D, and the axial length of the first section 10a is L2, then D and L2 need to satisfy: L2 < D.
[0067] In this embodiment, a second imaging member 721 is further provided at the distal end of the sheath tube 72, so as to facilitate identifying the position of the distal end of the sheath tube 72 relative to the main stent 10 together with the first imaging member 15 during the retraction process of the sheath tube 72. A ring of imaging wires can be arranged along the circumferential direction of the distal end of the sheath tube 72.
[0068] Due to the arrangement of the first restraint wire 73 and the second restraint wire 74 in the stent system provided by the present invention, and the sheath core assembly 71 passing through the distal end of the main stent 10 and exiting from the free end of the branch stent 20, only the branch guide wire 902 can be constructed as the delivery channel of the stent system, and the branch stent 20 can be directly delivered along the branch guide wire 902 to the branch blood vessel without setting other delivery guide wires, so as to reduce the number of selected guide wires.
[0069] Taking the implantation of the branch stent 20 into the left subclavian branch artery 901 as an example, the delivery process of implanting the above stent system into the aortic arch of the human body is as follows:
[0070] First, select the branch guide wire 902 from the femoral artery into the left subclavian branch artery 901 to be implanted to establish a delivery channel, as Figure 9 shown;
[0071] Then, deliver the branch stent 20 in the stent system along the branch guide wire 902 to the left subclavian branch artery 901; further, finely adjust the position of the stent system along the branch guide wire 902 so that the main stent 10 reaches the orifice of the left subclavian branch artery but does not enter the left subclavian branch artery 901 (a imaging member can be provided at the proximal end of the main stent 10, or a imaging member can be provided at the position corresponding to the proximal end of the main stent 10 of the corresponding branch stent to indicate the position of the proximal end of the main stent 10 at the most distal end of the stent system, which is convenient for retracting the sheath tube 72 so that the first section 10a of the main stent 10 can be released in the main cavity in a semi-restrained state), retract the sheath tube 72 to the orifice of the left subclavian branch artery 901 to expose part of the branch stent 20 (it is also possible to first retract the sheath tube 72 to the proximal end of the main stent 10, and then finely adjust the distal end of the sheath tube 72 to the orifice of the left subclavian branch artery 901); continue to retract the sheath tube 72. When the second imaging member 721 at the distal end of the sheath tube 72 meets the first imaging member 15 on the main stent 10, pause the retraction of the sheath tube 72. At this time, the first section 10a of the main stent 10 exposes the sheath tube 72, asFigure 10 Combination Figure 7 As shown;
[0072] The branch stent 20 is continuously delivered along the branch guide wire 902 toward the branch blood vessel until the first end of the branch stent 20 is delivered to the opening of the left subclavian branch artery 901. Figure 11 Definition Figure 10 The middle branch stent 20 is partially delivered to the branch vessel, and the first section 10a of the main stent 10 is exposed outside the sheath tube 72 until Figure 11 The pushing process of the first end of the branch stent 20 being delivered to the orifice of the left subclavian branch artery 901 is a micro-pushing process. In this process, since the aortic arch is arch-shaped, the tangent point at the orifice of the left subclavian branch artery 901 is defined as X, the tangent passing through the tangent point X is defined as L5, and the vertical line passing through the tangent point X and perpendicular to the tangent line L5 is defined as L6. With L6 as the boundary, the arch portion extending toward the ascending main direction is defined as the upper arch portion, and the arch portion extending toward the descending main direction is defined as the lower arch portion, as shown in FIG. Figure 9 As shown, since the axial direction of the tubular structure of the branch stent 20 and the axial direction of the tubular structure of the main stent 10 have a certain angle (70° to 90°), when the distal end of the sheath 72 is withdrawn from the proximal end of the first section 10a to the process where the second developing member 721 meets the first developing member 15, the first section 10a of the main stent 10 releases the restraint of the sheath 72 and moves away from the branch stent 20 surrounding the branch guide wire 902, as shown in FIG. Figure 10 As shown, at this time, since the first section 10a and the branch stent 20 are both in a semi-constrained state, the stent system can be slowly pushed as a whole so that the first end of the branch stent 20 is delivered to the orifice of the left subclavian branch artery 901, and the first section 10a of the main stent 10 passes over the orifice of the left subclavian branch artery 901 and moves toward the upper arch, as shown in FIG. Figure 11 As shown, the branch stent 20 and the main stent 10 are transported to predetermined positions in their respective axial directions, and then the sheath 72 and their respective binding wires are withdrawn, so that the coated stent 100 is completely released in the aortic arch.
[0073] For example, the first half binding structure 14 is provided on all the corrugations in the axial direction of the main support 10. Figure 12 As shown, the sheath tube 72 can be withdrawn first until the distal end of the main stent 10 is completely exposed from the sheath tube 72. Since the main stent 10 and the branch stent 20 are respectively restrained by the first semi-restraint structure 14 and the second semi-restraint structure 21 and are in a semi-restraint state, the sheath tube 72 can be withdrawn first and then until the distal end of the main stent 10 is completely exposed from the sheath tube 72. Figure 10During the process that the sheath tube 72 in [[ ]] stays at the proximal end of the second section 10b, directly withdraw the sheath tube 72 until the distal end of the main body stent 10 is completely exposed from the sheath tube 72. Then, as the stent system is pushed forward, the main body stent 10 and the branch stent 20 can move forward along their respective axial directions in their respective aortic arch cavities or branch blood vessel cavities. To further ensure the safety of the above micro-pushing process, a pre-bent portion 732 attached to the first section 10a of the main body stent 10 and a straight portion 731 extending along the second section 10b can be provided. As Figure 8-8b shown, where the pre-bending angle of the pre-bent portion 732 relative to the straight portion 731 is greater than 20°. The first section 10a is in a semi-restrained state, presenting a state similar to a solid cylinder. As Figure 12 combined with Figure 8b shown, the pre-bent portion 732 can press against the first section 10a in the semi-restrained state away from the major curvature side 900a of the blood vessel, so as to ensure that the state of the first section 10a released from the sheath tube 72 in the semi-restrained state is more curved towards the second side 102 relative to the branch stent 20 than the first section 10a of the main body stent 10 in the natural state. This makes the first section 10a of the main body stent 10 not stick to the major curvature side of the aortic arch during the above micro-pushing process, and the proximal end of the first section 10a of the main body stent 10 bends towards the minor curvature side of the aortic arch, thereby avoiding the proximal end of the first section 10a piercing the blood vessel wall on the major curvature side of the aortic arch during the micro-pushing process. Then, withdraw the second restraint wire 74 and the first restraint wire 73 in sequence, so that the main body stent 10 and the branch stent 20 are released from the semi-restrained state and completely released to the natural expansion state. Finally, withdraw the delivery device 70 again to complete the release of the covered stent. As Figure 13 shown.
[0074] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.
[0075] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.
Claims
1. A covered stent, characterized in that, The covered stent includes a main stent and a branch stent. The main stent includes a first side and a second side. The main stent includes a branch opening provided on the first side. The first end of the branch stent is connected to the branch opening. The main stent includes a first section extending from the branch opening towards the proximal end. The first section is provided with a first semi-restraining structure, and the branch stent is provided with a second semi-restraining structure. Define the length of the branch stent along its axial direction as L1, and define the length of the first section along its axial direction as L2. L1 and L2 satisfy: L1 > L2.
2. The covered stent according to claim 1, wherein, The main stent further includes a second section extending from the branch opening towards the distal end. The part of the second section close to the first section is also provided with the first semi-restraining structure.
3. The covered stent according to claim 1, wherein The proximal end of the second section is provided with a first radiopaque member.
4. The covered stent according to claim 3, characterized in that, The second section includes a first wave ring. The first wave ring is provided on the proximal end side of the second section. The first wave ring includes a plurality of wave rods. The distal end of the first radiopaque member does not axially exceed the midpoint of any wave rod.
5. The covered stent according to claim 4, characterized in that, The first wave ring includes a wave crest close to the proximal end. The first radiopaque member includes a radiopaque wire wound along the wave crest of the first wave ring. Or, the first section includes a second wave ring. The second wave ring is close to the second section. The first radiopaque member is sutured to the membrane between the first wave ring and the second wave ring.
6. The covered stent according to claim 1, characterized in that, The axial length of the first section is less than its diameter in the natural state.
7. The covered stent according to claim 1, characterized in that, The ratio of the diameter of the circumscribed circle of the cross-section of the first section in the semi-restrained state to the diameter of the circumscribed circle of the cross-section of the first section of the main stent in the natural expansion state is: 0.14 - 0.
4.
8. A bracket system, characterized in that, The stent system includes a delivery device and the covered stent as described in any one of claims 1 - 7. The delivery device includes a sheath-core assembly, a sheath tube, a first restraining wire, and a second restraining wire. The branch stent includes a free end opposite to the first end. When the covered stent is compressed in the sheath tube, the sheath-core assembly penetrates from the distal end of the main stent to the free end of the branch stent and exits. The first restraining wire axially passes through the first semi-restraining structure in sequence. The branch stent folds towards the proximal end of the first section in the axial direction of the main stent. The second restraining wire axially passes through the second semi-restraining structure, and the branch stent and the main stent are radially compressed in the sheath tube.
9. The stent system according to claim 8, characterized in that The first restraining wire includes a pre-bent part and a straight part connected to each other. The pre-bent part is provided on the distal end side of the first restraining wire. The pre-bending angle of the pre-bent part relative to the straight part is greater than 20°. Or, the stent system further includes a pre-bent rod with a distal pre-bend. The pre-bent rod includes a pre-bent part and a straight part connected to each other. The pre-bent part is provided on the distal end side of the pre-bent rod. The pre-bending angle of the pre-bent part relative to the straight part is greater than 20°, and the pre-bent part is correspondingly provided at the first section of the main stent.
10. A bracket system, characterized in that, The stent system includes a delivery device such as the covered stent according to any one of claims 3-5. The delivery device includes a sheath-core assembly, a sheath, a first binding wire, and a second binding wire. The branch stent includes a free end opposite to the first end. When the covered stent is compressed in the sheath, the sheath-core assembly penetrates from the distal end of the main stent to the free end of the branch stent and exits. The first binding wire axially passes through the first half-binding structure in sequence. The branch stent is folded in the axial direction of the main stent towards the proximal end of the first section. The second binding wire axially passes through the second half-binding structure, and the branch stent and the main stent are radially compressed within the sheath. A second imaging member is provided at the distal end of the sheath.
Citation Information
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Stent system
CN121667894A