A covered stent

Abstract

The present invention discloses a covered stent, comprising a balloon-expandable stent, a self-expandable stent, a connecting stent and a covering membrane; wherein, one end of the connecting stent is connected to the balloon-expandable stent, and the other end is connected to the self-expandable stent; the balloon-expandable stent, the self-expandable stent and the connecting stent are disposed on the outer surface of the covering membrane; and holes are provided on the covering membrane corresponding to the connecting stent.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and particularly to a covered stent. Background Art

[0002] Vascular stenosis is a common and frequently-occurring disease clinically, and stenosis at the cross-vessel of the femoral artery and the deep femoral artery is even more common in blood vessels. Since there are no very obvious symptoms in the initial and middle stages of femoral artery stenosis, most cases are in the late stage when this kind of lesion is detected, and a stent needs to be placed at the vascular lesion for treatment.

[0003] The currently used stents may not only have the problem of blocking blood vessels by the stent body, but also have extremely high requirements for the doctor's experience judgment and professional quality. If there is a judgment error or operation error during the operation, serious consequences may occur, endangering the life and health of patients. Based on this, it is necessary to provide a new type of stent to solve the above problems. Summary of the Invention

[0004] An embodiment of the present specification provides a covered stent, which includes a balloon-expandable stent, a self-expandable stent, a connecting stent, and a film; wherein, one end of the connecting stent is connected to the balloon-expandable stent, and the other end is connected to the self-expandable stent; the balloon-expandable stent, the self-expandable stent, and the connecting stent are arranged on the outer surface of the film; and there are holes on the film corresponding to the connecting stent.

[0005] In some embodiments, the connecting stent includes metal wires arranged crosswise.

[0006] In some embodiments, the cross-section of the metal wires is non-fixed connection.

[0007] In some embodiments, the metal wires include nitinol wires.

[0008] In some embodiments, the balloon-expandable stent is located at the distal end of the covered stent, the self-expandable stent is located at the proximal end of the covered stent, and the connecting stent is connected between one end of the balloon-expandable stent close to the self-expandable stent and one end of the self-expandable stent close to the balloon-expandable stent.

[0009] In some embodiments, markers are arranged around the holes, and the material of the markers includes platinum-iridium alloy or gold; the markers are in the shape of round cakes, and the thickness in the middle of the markers is greater than the thickness at the edge.

[0010] In some embodiments, a reinforcing layer is arranged at the edge of the holes, and the shape of the reinforcing layer matches the shape of the holes.

[0011] In some embodiments, the material of the reinforcing layer is the same as that of the film coating, and the reinforcing layer and the film coating are fixed by heat melting.

[0012] In some embodiments, the material of the balloon-expandable stent is metal, and the materials of the connecting stent and the self-expandable stent include nitinol alloy.

[0013] In some embodiments, the self-expandable stent includes a plurality of metal wires, and the plurality of metal wires are sewn on the film coating along the circumferential direction of the film-coated stent.

[0014] In some embodiments, the metal wires are wavy, and at least one metal wire near the end of the balloon-expandable stent is connected to the connecting stent.

[0015] In some embodiments, the ratio of the length of the connecting stent to the length of the balloon-expandable stent or the self-expandable stent is between 1:1 and 1:2. Description of the Drawings

[0016] The embodiments of this specification will be further described in the form of exemplary embodiments, and these exemplary embodiments will be described in detail through the drawings. These embodiments are not restrictive. In these embodiments, the same numbers represent the same structures, where:

[0017] Figure 1 is a schematic structural diagram of a film-coated stent provided by some embodiments of this specification.

[0018] Figure 2 is a schematic structural diagram of the film coating in the film-coated stent provided by some embodiments of this specification.

[0019] Figure 3 is a schematic structural diagram of the film coating in the film-coated stent provided by some other embodiments of this specification.

[0020] Figure 4 is a schematic interface diagram of the film-coated stent provided by some other embodiments of this specification.

[0021] Figure 5 is a schematic structural diagram of the film-coated stent provided by some other embodiments of this specification. Detailed Description of the Embodiments

[0022] To more clearly illustrate the technical solutions of the embodiments of this specification, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some examples or embodiments of this specification. For those of ordinary skill in the art, without creative efforts, this specification can also be applied to other similar scenarios based on these drawings. It should be understood that these exemplary embodiments are only provided to enable those skilled in the relevant art to better understand and then implement this specification, rather than limiting the scope of this specification in any way. Unless obvious from the language context or otherwise stated, the same reference numerals in the figures represent the same structure or operation.

[0023] As shown in this specification and the claims, unless the context clearly indicates otherwise, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment".

[0024] In the description of this specification, it should be understood that the orientation or positional relationships indicated by terms such as "distal end", "proximal end", "inner", "outer", "far from", "close to", "one end", etc. are based on the orientation or positional relationships shown in the accompanying drawings. It is only for the convenience of describing this specification and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to this specification.

[0025] In this specification, unless otherwise clearly defined and limited, terms such as "install", "connect", "join", "fix", etc. should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or integrated; it can be directly connected or indirectly connected through an intermediate medium; it can be the communication inside two elements or can also represent the interaction relationship between two elements. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in this specification can be understood according to specific circumstances.

[0026] Narrowing at the vascular crossing is a common disease in blood vessels and usually requires placing a stent at the diseased blood vessel site for treatment. However, the currently used stents may not only have the problem of the stent body blocking the blood vessel, but also have extremely high requirements for the doctor's experience judgment and professional quality. If there are judgment errors or operation errors during the operation, serious consequences may occur, endangering the life and health of the patient.

[0027] In view of the above problems, embodiments of this specification provide a novel covered stent to improve the working performance, safety, and reliability of the stent. The covered stent provided by the embodiments of this specification will be described in detail below with reference to the accompanying drawings.

[0028] Figure 1 It is a schematic structural diagram of a covered stent provided by some embodiments of this specification.

[0029] Referring to Figure 1 , the covered stent 100 provided by some embodiments of this specification may include a balloon-expandable stent 110, a self-expanding stent 120, a connecting stent 130, and a covering film ( Figure 1 not shown in the figure). In some embodiments, the covered stent 100 can be applied at the vascular intersection to open the occluded vascular passage. This structure can take into account the advantages of the balloon-expandable stent 110 while increasing the stent length and flexibility, enhancing its ability to handle longer lesions, and better adapting to the physiological curvature of blood vessels, thereby better conforming to blood vessels.

[0030] Among them, the balloon-expandable stent 110 can refer to a stent structure with a certain radial expansion ability. In some embodiments, the balloon-expandable stent 110 can be expanded under the action of a balloon disposed inside it, so as to support the blood vessel wall and be fixed relative to the blood vessel wall. For example, after introducing gas or liquid into the internal balloon, the balloon can drive the balloon-expandable stent 110 to expand together, and then the blood vessel wall expands under the action of the balloon-expandable stent 110, and the balloon-expandable stent 110 remains fixed relative to the blood vessel wall. In some embodiments, the balloon-expandable stent 110 can be a tubular structure, and its material can be metal, such as stainless steel. In some embodiments, the balloon-expandable stent 110 can be integrally cut from stainless steel material.

[0031] The self-expanding stent 120 can refer to a stent structure with an automatic expansion ability. In some embodiments, the self-expanding stent 120 can automatically expand after entering the blood vessel under the influence of the internal environment of the blood vessel. For example, it generates thermal expansion by absorbing the blood temperature in the blood vessel, so as to be fixed relative to the blood vessel wall at another position, preventing the stent from slipping due to insufficient expansion of the balloon-expandable stent 110 or local vascular ulcer. In some embodiments, the self-expanding stent 120 can be a tubular structure. This structure provides a comprehensive solution combining multiple fixing methods for the positioning and fixing of the stent in the blood vessel, taking into account the advantages of different stent solutions. In some embodiments, the material of the self-expanding stent 120 can include nickel-titanium alloy, which can have good deformation ability and deformation recovery ability. It should be noted that the size of the self-expanding stent 120 after expansion can be the same as or different from the size of the balloon-expandable stent 110 after expansion.

[0032] The connecting bracket 130 may refer to a connecting structure. In some embodiments, the connecting bracket 130 may connect the balloon-expandable stent 110 and the self-expanding stent 120. Specifically, one end thereof may be connected to the balloon-expandable stent 110, and the other end may be connected to the self-expanding stent 120. In some embodiments, the material of the connecting bracket 130 may include nitinol.

[0033] The membrane may refer to a membranous structure composed of one or more layers of thin films. In some embodiments, the membrane may be used to simulate the blood vessel wall to reduce the resistance to blood flow caused by the stent body. In some embodiments, the material used for the membrane may include PTFE (Polytetrafluoroethylene, also known as Teflon).

[0034] In some embodiments, the balloon-expandable stent 110, the self-expanding stent 120, and the connecting bracket 130 may be disposed on the outer surface of the membrane. Exemplarily, in some embodiments, one or more of the balloon-expandable stent 110, the self-expanding stent 120, and the connecting bracket 130 may be fixed to the outer surface of the membrane by sewing. When the balloon-expandable stent 110, the self-expanding stent 120, and the connecting bracket 130 expand, they can drive the membrane to expand together, thereby increasing the effective diameter of the internal channel of the membrane, reducing the obstruction to blood, and preventing the stent or the membrane body from blocking blood circulation. It should be noted that in the embodiments of this specification, one or more of the balloon-expandable stent 110, the self-expanding stent 120, and the connecting bracket 130 may be fixed to the outer surface of the membrane by, but not limited to, sewing. For example, in some other embodiments, an adhesive method may be used.

[0035] It should be noted that Figure 1For illustrative purposes only, the covered stent 100 provided in the embodiments of this specification may include more structures or be used in cooperation with other structures. For example, in some embodiments, the covered stent 100 may cooperate with an operating handle (not shown in the figure). An operator (such as a doctor) can control the covered stent to enter the blood vessel through the operating handle and expand at a target position (such as a blood vessel intersection), so that it remains relatively fixed with the blood vessel. In some embodiments, the balloon-expandable stent 110 may be located at the distal end of the covered stent 100, and the self-expanding stent 120 may be located at the proximal end of the covered stent 100. The connecting stent may be connected between one end of the balloon-expandable stent 110 close to the self-expanding stent 120 and one end of the self-expanding stent 120 close to the balloon-expandable stent 110. The balloon-expandable stent 110, the connecting stent 130, and the self-expanding stent 120 may enter the blood vessel in sequence and act on the main blood vessel 210 at the blood vessel intersection. This structure adds a transition between the balloon-expandable stent 110 and the self-expanding stent 120, which can effectively avoid problems caused by the direct connection of the self-expanding stent 120 and the balloon-expandable stent 110. For example, when the self-expanding stent 120 has not been sheathed and released, the connection between the balloon-expandable stent 110 and the self-expanding stent 120 cannot be expanded to the required size due to the limitation of the sheath; for another example, in order to expand the entire balloon-expandable stent 110 to the required size, a part of the self-expanding stent 120 needs to be pre-released, thus losing the opportunity to adjust the position of the stent.

[0036] It should be noted that in this specification, the "distal end of the covered stent 100" may refer to the end that is far from the operating handle during the operation or the end that first enters the blood vessel during the operation; the "proximal end of the covered stent 100" may refer to the end that is close to the operating handle during the operation or the end that enters the blood vessel later during the operation.

[0037] Continue to refer to Figure 1 , holes 140 may be formed in the covered membrane corresponding to the connecting stent 130. The holes 140 can be used to align with the branch blood vessel 220 at the blood vessel intersection, so that the blood in the main blood vessel 210 can flow into the branch blood vessel 220 through the holes 140, thereby improving the occlusion condition at the blood vessel branch and forming a good passage at the blood vessel intersection. It should be noted that in some embodiments, the holes 140 may be round holes, oval holes, square holes or other regular or irregular shapes.

[0038] Continue to refer to Figure 1, in some embodiments, the connecting stent 130 may include a plurality of intersecting metal wires, wherein both ends of each metal wire are respectively connected to the balloon-expandable stent 110 and the self-expandable stent 120. In some embodiments, the plurality of intersecting metal wires may form a net structure, and the net structure may enclose a tubular structure along the circumferences of the balloon-expandable stent 110 and the self-expandable stent 120 and be respectively connected to the balloon-expandable stent 110 and the self-expandable stent 120. In some embodiments, each metal wire in the connecting stent 130 may be linear, curved or zigzag. It should be noted that in this specification, the intersecting relationship between the metal wires may refer to the intersecting relationship in a plane (such as a projection plane) (that is, there is an intersecting relationship between the two in the projection plane, but they may not be in contact), or it may refer to the intersecting relationship in space (that is, there is a contact or connection relationship between the two at the intersection).

[0039] In some embodiments, the intersections of the metal wires in the connecting stent 130 may be non-fixed connections, that is, the metal wires can move freely at the intersections. In some embodiments, the same metal wire may intersect with multiple (two or more) other metal wires, and the intersections of the metal wire with different metal wires may be on the same side or different sides (such as the side close to the membrane or the side away from the membrane).

[0040] In some embodiments, the metal wires in the connecting stent 130 may be partially or entirely sewn on the outer surface of the membrane. When the connecting stent 130 is released and deployed, it can effectively support the membrane, drive the membrane to expand together, and thus ensure the effective diameter of the lumen of the stent.

[0041] In some embodiments, the metal wires in the connecting stent 130 may include nitinol wires, which have good elasticity. By cross-sewing the nitinol wires on the outer surface of the membrane, multiple sets of scissor mechanisms can be formed. Combining the elasticity of the nitinol wires, the connecting stent 130 can be better folded in the delivery sheath. In addition, since the nitinol wire itself has good strength and elasticity, when it is combined with the balloon-expandable stent 110 and the self-expandable stent 120 with a certain rigidity, the overall covered stent 100 can also have good pushability and bending performance.

[0042] In some embodiments, both ends of the scissor mechanism of the metal wires of the connecting stent 130 may be respectively fixed to the balloon-expandable stent 110 and the self-expandable stent 120. When the balloon-expandable stent 110 and the self-expandable stent 120 expand, they can drive the connecting stent 130 to expand together, so that the expansion degree of the connecting stent 130 depends on the expansion states of the balloon-expandable stent 110 and the self-expandable stent 120, and further enables the connecting stent 130 to have better adaptability to blood vessels.

[0043] In some embodiments, after the connection bracket 130 is deployed, a rhombus can be formed between four adjacent metal wires, providing reasonable space for the hole 140 and also providing conditions for the expansion of the hole 140.

[0044] Figure 2 It is a schematic structural view of the film in the covered stent provided by some embodiments of this specification.

[0045] Refer to Figure 2 , in some embodiments, holes 140 can be formed at corresponding positions of the connection bracket 130 on the film 150. By aligning the holes 140 with the branch blood vessels 220, the blood in the main blood vessel 210 can flow to the branch blood vessels 220 through the holes 140, thereby improving the occlusion at the blood vessel branch and forming a good passage at the blood vessel intersection. In some embodiments, the main blood vessel 210 can be the femoral artery, and the branch blood vessel 220 can be the deep femoral artery. It should be noted that only examples are given in the embodiments of this specification. In some other embodiments, the main blood vessel 210 and the branch blood vessel 220 can be other blood vessels.

[0046] In some embodiments, in order to facilitate the alignment of the holes 140 with the branch blood vessels 220, markers 1401 can be provided around the holes 140. It should be noted that the markers 1401 can be developed under ray or acoustic wave detection to locate the position of the holes 140 in real time, thereby greatly reducing the operation difficulty of aligning the holes 140 with the branch blood vessels 220.

[0047] In some embodiments, the number of the markers 1401 can be three or more, and they can be distributed around the holes 140 at equal or unequal intervals.

[0048] In some embodiments, the material of the marker 1401 may include platinum-iridium alloy or gold. In some embodiments, the marker 1401 may be fixed on the surface of the film 150 by hot melting. In some embodiments, a PTFE coating layer may be formed on the surface of the marker 1401 by spraying or other means. When the marker 1401 is fixed to the film 150 by hot melting, the PTFE coating layer on the surface of the marker 1401 and the film 150 made of PTFE material can be integrated into one body under the heating state, so that the connection between the marker 1401 and the film 150 is closer, preventing the marker 1401 from falling off the film 150. In some embodiments, the thickness of the PTFE coating layer may be between 0.05 mm and 0.15 mm. For example, it may be 0.08 mm, 0.1 mm, 0.12 mm, etc. In some embodiments, by fixing the marker 1401 on the film 150 by hot melting, compared with using the suture method for fixation, the use of sutures for fixation can be avoided, so that the edge of the hole 140 is smoother, and the formation of thrombus around the hole 140 due to the existence of frictional resistance can be avoided.

[0049] Figure 3 It is a schematic diagram of the film structure provided by other embodiments of this specification.

[0050] Referring to Figure 3 , in some embodiments, a reinforcing layer 1402 may also be provided around the hole 140. The reinforcing layer 1402 may refer to a reinforcing structure with a strength greater than that of the film or a reinforcing structure for increasing the strength of the area around the hole 140. By providing the reinforcing layer 1402, the shape of the hole 140 can be supported and maintained after the stent is released, thereby preventing the effective diameter of the hole 140 from being too small and causing blockage. In some embodiments, the reinforcing layer 1402 may be provided along the edge of the hole 140, and its shape may match the shape of the hole 140.

[0051] In some embodiments, the aforementioned marker 1401 may be disposed between the film 150 and the reinforcing layer 1402. By wrapping and fixing the marker 1401 with the reinforcing layer 1402 and the film 150, the possibility of the marker 1401 falling off can be reduced to a greater extent.

[0052] In some embodiments, the material of the reinforcing layer 1402 may be the same as that of the film 150, thereby increasing the compatibility between the two to a certain extent. In other words, in some embodiments, the reinforcing layer 1402 may be made of PTFE. In some embodiments, the reinforcing layer 1402 and the film 150 may be fixedly connected by, but not limited to, hot melting.

[0053] Figure 4 It is a schematic cross-sectional view of the film stent provided by some embodiments of this specification.

[0054] Referring to Figure 4 , in some embodiments, the marker 1401 may be disc-shaped, and the thickness of the middle part thereof is greater than that of the edge part, so as to increase its thickness without affecting the working shape of the stent, thereby improving the developability of the marker 1401 under rays or sound waves, and further ensuring that the position and shape of the hole 140 can be accurately traced during use. In addition, by setting the thickness of the edge part to be smaller, there will be no step at the transition between the marker 1401 and the film 150, thus avoiding damage to blood vessels or forming an obstacle during placement.

[0055] Continuing to refer to Figure 4 , in some embodiments, the surface of the marker 1401 in contact with the film 150 may be a flat surface, and the surface in contact with the reinforcing layer 1402 may be a convex arc surface facing the reinforcing layer 1402, so as to avoid the film 150 from sagging inward and hindering blood flow while increasing the thickness of the middle part thereof.

[0056] In some embodiments, the diameter of the marker 1401 may be between 0.2 mm and 1 mm, and the thickness may be between 0.05 mm and 0.15 mm. For example, in some embodiments, the diameter of the marker 1401 may be 0.5 mm, and the thickness may be 0.1 mm. Referring to Figure 4 , in some embodiments, the surface of the marker 1401 may include a PTFE coating 1403. In some embodiments, the thickness of the PTFE coating 1403 may be between 0.05 mm and 0.15 mm.

[0057] Figure 5 FIG. is a schematic structural diagram of a film-covered stent provided in other embodiments of the present specification.

[0058] Referring to Figure 5, in some embodiments, one end of the balloon-expandable stent 110 away from the self-expandable stent 120 may include a first smooth band 111. In some embodiments, the first smooth band 111 may refer to a smooth structure for reducing resistance, which may be used to smooth the distal side of the covered stent 100, thereby avoiding the formation of thrombus at the end of the balloon-expandable stent 110 to block the blood vessel. In some embodiments, the first smooth band 111 may support the opening position of one end of the balloon-expandable stent 110 after the covered stent 100 is opened, thereby ensuring the effective diameter of the internal channel of the stent. During the stent implantation procedure, the balloon-expandable stent 110 may reach the lesion site first. Before releasing other positions of the stent, the operator (such as a doctor) may adjust the position and state of the balloon-expandable stent 110 according to the actual situation of the patient's blood vessel during the operation. When the shape and position of the balloon-expandable stent 110 meet the implantation requirements, this section of the stent can be expanded by controlling the balloon, thereby fixing one end of the covered stent 100.

[0059] In some embodiments, one end of the self-expandable stent 120 away from the balloon-expandable stent 110 may include a second smooth band 121. Similarly to the first smooth band 111, the second smooth band 121 may be used to smooth the proximal side of the covered stent 100, avoiding the formation of thrombus at the end of the self-expandable stent 120 to block the blood vessel. When the self-expandable stent 120 is implanted into the blood vessel and reaches the expansion condition, the self-expandable stent 120 can automatically expand, thereby fixing the other end of the covered stent 100. In addition, the second smooth band 121 may support the opening position of one end of the self-expandable stent 120 after the covered stent 100 is opened, thereby ensuring the effective diameter of the internal channel of the stent.

[0060] Referring to Figure 5 , in some embodiments, the self-expandable stent 120 may include a plurality of metal wires, and the plurality of metal wires may be sewn on the covering 150 along the circumferential direction of the covered stent 100. In some embodiments, the plurality of metal wires in the self-expandable stent 120 may be nitinol wires. In some embodiments, the plurality of metal wires in the self-expandable stent 120 may be arranged at equal or unequal intervals. In some embodiments, the spacing between the metal wires in the self-expandable stent 120 may be set according to the required stiffness. For example, when a certain part of the self-expandable stent 120 needs to have a greater stiffness, the metal wires at the corresponding position may have a relatively smaller spacing, such as 0.1 mm, 0.2 mm, etc.; while when a certain part of the self-expandable stent 120 needs to have a higher flexibility, the metal wires at the corresponding position may have a relatively larger spacing, such as 0.5 mm, 1 mm, etc.

[0061] In some embodiments, the plurality of metal wires in the self-expanding stent 120 may be wavy and arranged along the circumference of the stent graft 100. Exemplary wavy shapes may include sharp-angled wavy shapes and rounded-angled wavy shapes. In some embodiments, in order to facilitate folding so that the self-expanding stent 120 has a smaller volume after contraction, metal wires with sharp-angled wavy shapes may be preferred.

[0062] Reference Figure 5 In some embodiments, at least one of the multiple metal wires of the self-expanding stent 120 near one end of the balloon expandable stent 110 can be connected to the metal wire in the connecting stent 130, and the connection method can be but is not limited to welding. For example, in some embodiments, one end of each metal wire in the connecting stent 130 can be connected to the balloon expandable stent 110, and the other end can be connected to a metal wire in the self-expanding stent 120 that is closest to the balloon expandable stent 110; in some embodiments, to ensure the reliability of the connection between the metal wire in the connecting stent 130 and the metal wire in the self-expanding stent 120, one end of the metal wire in the connecting stent 130 can be connected to two or more metal wires in the self-expanding stent 120 at the same time, for example, a connecting section (not shown in the figure) can be added between two or more metal wires in the self-expanding stent 120 near the balloon expandable stent 110, so that the force is shared to the multiple metal wires in the self-expanding stent 120 through the connecting section.

[0063] Continue to refer to Figure 5 , each metal wire of the self-expanding stent 120 may include a crest and a trough, wherein the crest may refer to the end portion away from the balloon expandable stent 110, and the trough may refer to the end portion toward the balloon expandable stent 110. In some embodiments, the metal wire in the connecting stent 130 may be connected to the trough position of one or more metal wires of the self-expanding stent 120 near one end of the balloon expandable stent 110. It should be noted that the above is only an exemplary description, and in some other embodiments, the metal wire in the connecting stent 130 may be connected to the metal wire in the self-expanding stent 120 in other ways. For example, in some embodiments, the metal wire in the connecting stent 130 may be connected to the crest position of one or more metal wires of the self-expanding stent 120 near one end of the balloon expandable stent 110.

[0064] Considering that the pushing performance and bending performance of the covered stent 100 are related to the length relationship between the balloon-expandable stent 110, the self-expanding stent 120, and the connecting stent 130. Based on this, in some embodiments, in order to ensure both the pushability and bendability of the covered stent 100, the length ratio of the connecting stent 130 to the balloon-expandable stent 110 or the self-expanding stent 120 can be controlled between 1:1 and 1:2. Exemplarily, in some embodiments, the ratio of the length of the connecting stent 130 to the length of the balloon-expandable stent 110 can be 1:1.5, and the ratio of the length of the connecting stent 130 to the length of the self-expanding stent 120 can be 1:1.2; in other embodiments, the ratio of the length of the connecting stent 130 to the length of the balloon-expandable stent 110 can be 1:1.2, and the ratio of the length of the connecting stent 130 to the length of the self-expanding stent 120 can be 1:1.5. In some embodiments, the length of the connecting stent 130 can be between 10 mm and 15 mm.

[0065] In some embodiments, the covered stent 100 provided by the embodiments of this specification can be used with reference to the following steps:

[0066] step1. Puncture the blood vessel and insert a guide wire and a delivery sheath into the blood vessel lesion site.

[0067] step2. Deliver the covered stent 100 to the lesion site through the blood vessel sheath.

[0068] step3. Deliver the balloon-expandable stent 110 and the connecting stent 130 out of the blood vessel sheath.

[0069] step4. Insert another guide wire into the covered stent 100 and insert it into the branch blood vessel through the hole 140.

[0070] step5. Perform angiography at the blood vessel crossing to observe the connection between the hole 140 and the branch blood vessel.

[0071] step6. Adjust the position of the covered stent 100 so that the hole 140 forms a good connection with the branch blood vessel.

[0072] step7. Expand the balloon-expandable stent 110 through the balloon, and then fix the covered stent 100 relative to the blood vessel.

[0073] step8. Withdraw the blood vessel sheath to release and expand the self-expanding stent 120.

[0074] step9. The stent implantation is completed, withdraw the instrument, and bandage to stop bleeding.

[0075] In some embodiments, after the covered stent 100 is placed at the lesion location (e.g., the vascular crossing), the balloon-expandable stent 110 can be located more distally at the vascular crossing, the connecting stent 130 can be located at the branching position of the vascular crossing, and the hole 140 is aligned with the branch vessel, and the self-expanding stent 120 can be located proximally at the vascular crossing. In some embodiments, the vascular diameters corresponding to the balloon-expandable stent 110, the self-expanding stent 120, and the connecting stent 130 can be the same or different. For example, in some embodiments, the diameters of the balloon-expandable stent 110 and the self-expanding stent 120 after expansion can vary significantly. In this case, if balloons are used to expand the stents at both the proximal and distal ends, different balloons are required. Therefore, with the covered stent 100 provided in the embodiments of this specification, the self-expanding method is used to achieve expansion in the section corresponding to the self-expanding stent 120, which can avoid replacing the balloon during the operation, thereby reducing the surgical risk, the surgical cost, and saving the surgical time to a certain extent.

[0076] In addition, compared with the method of using self-expansion to expand the stent at both the proximal and distal ends, during the use of the covered stent 100 provided in the embodiments of this specification, the balloon-expandable stent 110 can be released first, then the stent state can be adjusted to align the hole 140 with the branch vessel, secondly, the balloon-expandable stent 110 can be positioned by expanding the balloon, and finally the self-expanding stent 120 can be released, thereby solving the problem that the position and state of the stent cannot be adjusted during the stent release process.

[0077] Some of the beneficial effects that the ablation device provided by some embodiments of this specification may bring include, but are not limited to: (1) By jointly forming a semi-covered stent with a balloon-expandable stent, a self-expanding stent, a connecting stent, and a covering film, while taking into account the advantages of the balloon-expandable stent, the stent length and flexibility can be increased, enhancing its ability to handle longer lesions and better adapting to the physiological curvature of blood vessels, thus better conforming to blood vessels; (2) By combining a balloon-expandable stent and a self-expanding stent, multiple fixing methods can be provided for the positioning and fixation of the stent in blood vessels, while taking into account the advantages of different stent solutions; (3) By connecting the balloon-expandable stent and the self-expanding stent with a connecting stent having a specific structure, a transition can be added between the balloon-expandable stent and the self-expanding stent, effectively avoiding problems caused by the direct connection of the self-expanding stent and the balloon-expandable stent, and improving the overall pushability and bending performance of the stent; (4) By fixing the marker on the covering film by means of heat melting, the edge of the marker can be made smoother, avoiding the formation of thrombus around the marker due to the existence of frictional resistance; (5) By providing a reinforcing layer around the hole, the shape of the hole can be supported and maintained after the stent is released, thereby preventing the effective diameter of the hole from being too small and causing blockage; (6) By wrapping and fixing the marker with the reinforcing layer and the covering film, the possibility of the marker falling off can be reduced; (7) By respectively providing a first smooth band and a second smooth band at the ends of the balloon-expandable stent and the self-expanding stent, the ends of the balloon-expandable stent and the covered stent can be made smooth, thus avoiding the formation of thrombus at the ends of the balloon-expandable stent and the self-expanding stent to block blood vessels.

[0078] It should be noted that the beneficial effects that may be produced by different embodiments are different. In different embodiments, the beneficial effects that may be produced may be any one or several combinations of the above, or any other beneficial effects that may be obtained.

[0079] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only an example and does not constitute a limitation to this specification. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this specification. Such modifications, improvements, and corrections are proposed in this specification, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this specification.

[0080] In the meantime, this specification uses specific terms to describe the embodiments of this specification. For example, "an embodiment", "one embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this specification can be appropriately combined.

[0081] Similarly, it should be noted that, in order to simplify the presentation disclosed in this specification and thus help with the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of this specification, sometimes multiple features are grouped into one embodiment, drawing, or description thereof. However, this method of disclosure does not mean that the features required by the subject matter of this specification are more than those mentioned in the claims. In fact, the features of the embodiments are fewer than all the features of the individual embodiments disclosed above.

[0082] In some embodiments, numbers are used to describe components and the quantities of attributes. It should be understood that such numbers used for the description of embodiments are, in some examples, modified by the modifiers "about", "approximately", or "substantially". Unless otherwise stated, "about", "approximately", or "substantially" indicate that the said numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, and such approximate values may change according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used in some embodiments of this specification to confirm the breadth of their scope are approximate values, in specific embodiments, the setting of such numerical values is as precise as possible within the feasible range.

[0083] For each patent, patent application, patent application publication, and other materials cited in this specification, such as articles, books, specifications, publications, documents, etc., their entire contents are hereby incorporated into this specification by reference. This excludes the application history documents that are inconsistent with or conflict with the content of this specification, and also excludes the documents that limit the broadest scope of the claims (currently or subsequently appended to this specification). It should be noted that if there are inconsistencies or conflicts between the descriptions, definitions, and / or uses of terms in the supplementary materials of this specification and the content described in this specification, the descriptions, definitions, and / or uses of terms in this specification shall prevail.

[0084] Finally, it should be understood that the embodiments described in this specification are only used to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be regarded as consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly presented and described in this specification.

Claims

1. A covered stent, characterized in that, The covered stent includes a balloon-expandable stent, a self-expandable stent, a connecting stent, and a membrane; wherein, One end of the connecting stent is connected to the balloon-expandable stent, and the other end is connected to the self-expandable stent; The length ratio of the connecting stent to the length of the balloon-expandable stent or the self-expandable stent is between 1:1 and 1:2; The balloon-expandable stent, the self-expandable stent, and the connecting stent are arranged on the outer surface of the membrane; holes are provided in the membrane corresponding to the connecting stent; a reinforcing layer is provided at the edge of the holes, and the shape of the reinforcing layer matches the shape of the holes; Markers are provided around the holes, and the markers are arranged between the membrane and the reinforcing layer; The connecting stent includes connecting stent wires arranged in a cross pattern; The intersections of the connecting stent wires are non-fixed connections, and a rhombus is formed between four adjacent connecting stent wires; The self-expandable stent includes multiple self-expandable stent wires, and the self-expandable stent wires are in a wavy shape.

2. The covered stent according to claim 1, wherein The connecting stent wires include nitinol wires.

3. The covered stent according to claim 1, wherein, The balloon-expandable stent is located at the distal end of the covered stent, the self-expandable stent is located at the proximal end of the covered stent, and the connecting stent is connected between one end of the balloon-expandable stent close to the self-expandable stent and one end of the self-expandable stent close to the balloon-expandable stent.

4. The covered stent according to claim 1, wherein The material of the markers includes platinum-iridium alloy or gold; the markers are in a disc shape, and the thickness in the middle of the markers is greater than the thickness at the edge part.

5. The covered stent according to claim 1, wherein The material of the reinforcing layer is the same as that of the membrane, and the reinforcing layer and the membrane are fixed by hot melting.

6. The covered stent according to claim 1, characterized in that, The material of the balloon-expandable stent is metal, and the materials of the connecting stent and the self-expandable stent include nitinol alloy.

7. The covered stent according to claim 1, characterized in that, The multiple self-expandable stent wires are sewn on the membrane along the circumferential direction of the covered stent.

8. The covered stent according to claim 1, characterized in that, At least one self-expandable stent wire at one end of the self-expandable stent wire close to the balloon-expandable stent is connected to the connecting stent.

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