Endovascular prosthesis

Abstract

The application discloses an intravascular prosthesis, comprising: a tubular body; a first film layer attached to the tubular body, the first film layer having extensibility, a constraint channel being arranged in the first film layer, the constraint channel extending spirally along the circumference of the tubular body; a constraint member, at least a part of the constraint member being arranged in the constraint channel, the constraint member being movable relative to the constraint channel; a constraint section on the tubular body corresponding to the constraint member, the constraint section comprising an adjustment state, in the adjustment state, the constraint member and the constraint channel are arranged to allow the constraint member to be fixed relative to the constraint channel by a resistance and to make the constraint section at least partially circumferentially contract; to allow the constraint member to move relative to the constraint channel to reduce the circumferential contraction degree of the constraint section when the constraint section is subjected to an expansion force; to allow the part of the constraint member corresponding to a target area of the constraint section to be circumferentially contracted to make the target area contract when the circumferential contraction degree of the constraint section is reduced in the process of further expansion of a first working area of the constraint section, the first working area and the target area being adjacent areas on the constraint section. The application can control the expansion degree of the intravascular prosthesis and realize reversible adjustment of the diameter of the intravascular prosthesis.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to an intravascular prosthesis. Background Technology

[0002] Intravascular prostheses are precision devices implanted inside blood vessels through minimally invasive interventional procedures, primarily used for diseased blood vessels that are narrowed, blocked, or dilated like aneurysms. Their core purposes are: to restore / maintain vascular patency (stents); to isolate the risk of vascular rupture / aneurysm (stent-type vessels); and to replace the function of diseased blood vessels (artificial blood vessels). However, the radial dimensions of existing intravascular prostheses (such as covered stents) are mostly fixed, requiring individual patients to choose from a variety of inner diameter specifications. Once the specifications are determined, it is difficult to readjust the stent after implantation. Clinically, the common practice is to place different sizes to correct the negative effects of inappropriate size selection, but this means higher surgical risks and costs.

[0003] Some intravascular prostheses have adjustable radial dimensions. For example, controllable-diameter stents used in transjugular intrahepatic portosystemic shunt (TIPS) procedures are generally divided into two types: balloon-expandable stents and self-expanding stents. Both types require balloon expansion to increase the inner diameter to the required size; the inner diameter is always expanded from small to large. Typically, a deformable material is added to the outer wall of the stent to shrink it. After implantation, balloon expansion deforms this material, reducing the circumferential constraint on the stent diameter and thus increasing its size. However, with this method, as the added deformable material expands, the stent further enlarges until it reaches force equilibrium with the external constraint space. In other words, the specific degree of expansion cannot be controlled during the expansion process.

[0004] In addition, such adjustable intravascular prostheses may still cause complications after clinical use, such as the need to narrow or even close the intravascular prosthesis cavity, such as decreased or failed liver function, heart failure, chronic hepatic encephalopathy, and stent-related hemolysis after TIPS.

[0005] However, since existing intravascular prostheses cannot shrink to a smaller size after full expansion, when the above-mentioned situation of needing to shrink is encountered after surgery, it is necessary to use other instruments with smaller diameters to perform a secondary surgery, such as placing a new intravascular prosthesis in parallel. This approach will increase the patient's pain and financial burden. Summary of the Invention

[0006] The main objective of this invention is to provide an intravascular prosthesis to solve the problems in related technologies where the degree of expansion cannot be controlled during the expansion process and the prosthesis cannot shrink to a smaller size after expansion.

[0007] To achieve the above objectives, the present invention provides an intravascular prosthesis, comprising:

[0008] Tubular body;

[0009] A first membrane layer is attached to the tubular body. The first membrane layer is extensible and has a constraint channel provided therein. The constraint channel extends in a spiral shape along the circumference of the tubular body.

[0010] A constraint member, at least a portion of which is disposed within the constraint channel and spirally wound around the tubular body;

[0011] The portion of the tubular body corresponding to the constraint member is a constraint segment, which includes an adjustment state. In the adjustment state, the constraint member and the constraint channel are configured as follows:

[0012] The constraint member is allowed to be fixed relative to the constraint channel under the action of resistance, and the constraint segment is at least partially circumferentially contracted.

[0013] When the constraint segment is subjected to an expansion force, the constraint member overcomes the resistance and moves relative to the constraint channel to reduce the degree of circumferential contraction of the constraint segment;

[0014] When the circumferential contraction of the constraint segment decreases, during the further expansion of the first working area of ​​the constraint segment, the portion of the constraint member corresponding to the target area of ​​the constraint segment is allowed to contract circumferentially, so that the target area is contracted. The first working area and the target area are adjacent areas on the constraint segment.

[0015] Optionally, the constraint member includes a connector and at least two locking members, the two locking members being located at opposite ends of the connector, the connector being located in the constraint channel and spirally wound.

[0016] The target area is located between the two card pieces at both ends, with one of the card pieces located in the first working area;

[0017] The size of the card is larger than the size of the constraint channel, and the card is configured as follows:

[0018] It can maintain the constraint segment in the adjusted state through resistance engagement with the constraint channel;

[0019] When the constraint segment is subjected to an expansion force in the adjusted state to reduce the circumferential contraction of the constraint segment, the locking element can overcome the resistance of the constraint channel and move within the constraint channel;

[0020] During the further expansion of the first work area, the card located within the first work area is fixed.

[0021] Optionally, the first membrane layer is provided with two openings, which are connected to the constraint channel. When the constraint segment is in the initial adjustment state, at least a portion of the card is located outside the opening and abuts against the opening. The card is configured to open the opening and enter the constraint channel when the constraint segment is subjected to an expansion force.

[0022] Optionally, the clip includes a tapered portion, wherein when the constraint section is in the initial adjustment state, the small diameter section of the tapered portion is located within the constraint channel, and the large diameter section of the tapered portion is located outside the opening and abuts against the opening.

[0023] Optionally, when the constraint segment is in its initial adjustment state, the card is completely located within the constraint channel.

[0024] Optionally, the cross-section of the connector is circular or polygonal.

[0025] Optionally, the target area of ​​the constraint segment is provided with developing points.

[0026] Optionally, three clips are provided, with two clips located at both ends of the connector and the other clip located near the center of the target area of ​​the constraint segment.

[0027] Optionally, when the constraint section is in the adjustment state, the clip located near the middle of the connector is close to the developing point.

[0028] Optionally, it further includes a second film layer, the second film layer being stretchable and attached to the outside of the first film layer.

[0029] Optionally, the constraint segment includes multiple turns of a waveform ring, and the connector includes multiple turns of a connecting segment connected end to end, with each turn of the waveform ring wrapping around at least one turn of the connecting segment.

[0030] Optionally, at least two turns of the connecting segment are wound around each turn of the waveform ring, with the two turns of the connecting segment respectively close to the crest and trough of the waveform ring it constrains.

[0031] Optionally, it also includes an anti-detachment structure, which is at least connected between the connecting segment and each of the waveform rings in the target area of ​​the constraint segment, thereby preventing the connecting segment from detaching from the waveform ring it is wrapped with.

[0032] Optionally, the anti-detachment structure includes a first anti-detachment component, which is arranged along the axial direction of the tubular body. The two ends of the first anti-detachment component are fixedly connected to the portions of the tubular body located at the two ends of the constraint section. The length of the first anti-detachment component is greater than or equal to the length of the constraint section.

[0033] Along the axial direction of the constraint section, the first anti-detachment component is alternately inserted outside the connecting segment and inside the wave ring.

[0034] Optionally, at least two first anti-detachment components are provided, and the two first anti-detachment components are symmetrically distributed.

[0035] Optionally, the first anti-detachment component is provided with a sleeve structure, which is sleeved on at least the connecting segment and the waveform ring in the target area of ​​the constraint segment.

[0036] Optionally, the first anti-detachment component includes a flexible anti-detachment line, the two ends of which are fixed to portions of the tubular body located at the two ends of the constraint segment. The anti-detachment line is knotted with at least the connecting segment and the wave ring of the target area of ​​the constraint segment to form the sleeve structure.

[0037] Optionally, the sleeve structure includes multiple collars, which are spaced apart along the axial direction of the first anti-detachment member.

[0038] Optionally, the anti-detachment structure includes a connecting ring that is sleeved on at least two waists of the wave ring, and the connecting segment wrapped around the wave ring slides through the connecting ring.

[0039] Optionally, the anti-detachment structure includes a sleeve that is wound and fixed around at least two waists of the wave ring, and the connecting segment wound around the wave ring slides through the sleeve.

[0040] Optionally, each turn of the connecting segment passes through at least one peak on the waveform loop it is wound around.

[0041] Optionally, each of the waveform rings is wound with at least two turns of the connecting segment, the two turns of the connecting segment passing through the crest and trough of the waveform ring to which it is wound.

[0042] Optionally, it also includes a sleeve, the sleeve being extensible, the inner diameter of the sleeve being the same as the outer diameter of the constraint segment in the initial adjustment state, the sleeve being used to fit over the constraint segment when the constraint segment contracts to the target loading diameter due to external constraint force, the constraint segment expanding to fit against the sleeve after the external constraint force is removed;

[0043] When the constrained section is subjected to an expansion force, it can overcome the constraint force of the sleeve to change the degree of contraction.

[0044] Optionally, in the initial adjustment state, the constraint segment includes a first end, a second end, and a first central portion located between the first end and the second end, the first end and the second end gradually transitioning outward to a first diameter, the first central portion remaining at a second diameter, and the first diameter being greater than or equal to the second diameter;

[0045] In the initial adjustment state, the sleeve fits tightly against the first end, the second end, and the first central portion.

[0046] Optionally, a sleeve constraint is provided inside the sleeve, the sleeve constraint is spirally wound around the circumference of the sleeve, the sleeve constraint is configured to overcome resistance and move inside the sleeve, and in the initial state, the sleeve constraint and the sleeve are relatively fixed by resistance.

[0047] Optionally, the sleeve constraint members are provided in multiples, and the multiple sleeve constraint members are distributed at intervals to form a discontinuous helical winding structure; or,

[0048] The ends of adjacent sleeve constraint members are joined together circumferentially or superimposed axially.

[0049] Optionally, the constraint members are configured as two or more spaced segments, so that the tubular body forms two or more constraint segments.

[0050] In this embodiment of the invention, firstly, the helically wound constraint member, in conjunction with the first membrane layer, enables circumferential contraction of the constraint segment on the tubular body, reducing the diameter of the constraint segment. After the intravascular prosthesis is loaded into the delivery device, the entire prosthesis is at its maximum contraction level, at which point the constraint segment is in its initial state.

[0051] Once the intravascular prosthesis is delivered to the lesion site, it is released by withdrawing the sheath. The restraint segment expands under its own expansion force and is maintained at a corresponding diameter by the cooperation of the restraint components and the restraint channel. This diameter is the design diameter. For the restraint segment, this diameter may be the same or different in different parts. At this time, the restraint segment is in an adjustment state.

[0052] In the adjustable state, a device capable of applying expansion force to the constrained segment of the tubular body can be introduced into the constrained segment (e.g., an inflatable balloon is introduced into the constrained segment), applying an expansion force from the inside out through the balloon. Under this expansion force, the constraining member located within the constrained channel moves relative to the constrained channel, and the diameter of the spiral structure formed by the winding of the constraining member increases while the number of spiral turns decreases. The portion of the constrained segment subjected to this expansion force expands, reducing the circumferential contraction of the constrained segment. Since the constraining member remains within the constrained channel throughout this process, it still provides constraint on the constrained segment after cooperating with the constrained channel. Therefore, when the balloon stops applying expansion force to the constrained segment, the constrained segment will remain in its current state. In other words, before the constrained segment reaches its designed maximum diameter, the constrained segment can be maintained in any adjustable state through the constraining member and the constrained channel, meaning the degree of expansion of the constrained segment is controllable. This solves the technical problem in related technologies where the degree of expansion of intravascular prostheses cannot be controlled during expansion.

[0053] In the adjusted state, after the circumferential contraction of the constraint segment decreases, an expansion force can be applied again to the first working area of ​​the constraint segment using a device such as a balloon. Under the action of this expansion force, the first working area will expand further. To achieve this expansion, the portion of the first membrane layer corresponding to the first working area and the portion of the constraint member corresponding to the first working area cooperate with each other, pulling the portion of the constraint member corresponding to the target area to cause circumferential contraction, that is, the diameter of the spiral structure of this portion decreases, causing the target area to shrink and reducing its diameter. Therefore, in this embodiment, with the cooperation of the first membrane layer and the constraint member, it is also possible to further apply an expansion force to a portion of the constraint segment, causing a portion of the constraint segment to shrink, thereby achieving reversible adjustment of the diameter of the constraint segment, thus solving the problem in related technologies where the diameter of intravascular prostheses cannot shrink to a smaller size after expansion. Attached Figure Description

[0054] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention, making other features, objects, and advantages of the invention more apparent. The illustrative embodiments of the invention illustrated in the drawings and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0055] Figure 1 This is a schematic diagram of the perspective structure of the intravascular prosthesis according to an embodiment of the present invention;

[0056] Figure 2 This is a perspective structural diagram of an intravascular prosthesis that is a self-expanding stent according to an embodiment of the present invention;

[0057] Figure 3 This is a schematic diagram of the structure of the constraint segment in the initial adjustment state according to an embodiment of the present invention;

[0058] Figure 4 This is a schematic diagram of the structure of the constraint segment in the adjustment state according to an embodiment of the present invention;

[0059] Figure 5 This is a schematic diagram of the structure after the target area has been shrunk according to an embodiment of the present invention;

[0060] Figure 6 This is a schematic diagram of the structure of the intravascular prosthesis in its initial adjustment state after three clips are installed according to an embodiment of the present invention;

[0061] Figure 7 This is a schematic diagram of the structure of the intravascular prosthesis in an adjustable state after three clips are installed according to an embodiment of the present invention;

[0062] Figure 8 This is a schematic diagram of one embodiment of the anti-detachment structure according to the present invention;

[0063] Figure 9 This is a schematic diagram of one embodiment of the anti-detachment structure according to an embodiment of the present invention;

[0064] Figure 10 yes Figure 9 A simplified schematic diagram of a portion of the image;

[0065] Figure 11 This is a schematic diagram of a socket structure according to an embodiment of the present invention;

[0066] Figure 12 This is a schematic diagram of an anti-detachment structure according to an embodiment of the present invention;

[0067] Figure 13 This is a schematic diagram of an anti-detachment structure according to an embodiment of the present invention;

[0068] Figure 14 yes Figure 13 A magnified schematic diagram of part A in the middle;

[0069] Figure 15 This is a schematic diagram of the structure of an intravascular prosthesis according to an embodiment of the present invention;

[0070] Figure 16 yes Figure 15 The diagram shown illustrates the constraint segment in its initial adjustment state in the embodiment.

[0071] Figure 17 This is a schematic diagram of the structure of an intravascular prosthesis according to another embodiment of the present invention;

[0072] Figure 18 This is a schematic diagram of the constrained segment after shrinkage and with a diameter of D1 according to an embodiment of the present invention.

[0073] Figure 19 This is a schematic diagram of the sleeve according to an embodiment of the present invention;

[0074] Figure 20 This is a schematic diagram showing the diameter of the constrained segment shrinking to D3 under the action of an external constraining force according to an embodiment of the present invention;

[0075] Figure 21 This is a schematic diagram of the sleeve assembly process according to an embodiment of the present invention;

[0076] Figure 22 This is a schematic diagram of the sleeve assembly according to an embodiment of the present invention;

[0077] Figure 23 This is a perspective structural diagram of the sleeve according to an embodiment of the present invention;

[0078] Figure 24 This is a schematic diagram of the sleeve constraint component according to an embodiment of the present invention;

[0079] Figure 25 This is a schematic diagram of the sleeve constraint component according to another embodiment of the present invention;

[0080] Figure 26 This is a schematic diagram of a structure in an embodiment of the present invention where the constraint segment is set to two segments;

[0081] Among them, 1. Constraint component; 100. Connector; 1000. Connecting segment; 101. Clip; 102. First constraint segment; 103. Second constraint segment; 2. First film layer; 20. Opening; 21. Constraint channel; 3. Tubular body; 30. Constraint segment; 300. Waveform ring; 4. Coating; 5. Imaging point; 6. Balloon; 7. First working area; 8. Target area; 9. Second working area; 10. First anti-detachment component; 11. Sleeve structure; 120. Connecting ring; 121. Wire sleeve; 13. Tube; 14. Loading fixture; 15. Tube constraint component. Detailed Implementation

[0082] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0083] To solve related technical problems, such as Figure 1 As shown, an embodiment of the present invention provides an intravascular prosthesis, comprising:

[0084] Tubular body 3;

[0085] The first membrane layer 2 is attached to the tubular body 3. The first membrane layer 2 is extensible. A constraint channel 21 is provided in the first membrane layer 2. The constraint channel 21 extends spirally along the circumference of the tubular body 3.

[0086] Constraint 1, at least a portion of which is disposed within the constraint channel 21 and spirally wound around the tubular body 3;

[0087] The portion of the tubular body 3 corresponding to the constraint member 1 is the constraint segment 30. The constraint segment 30 includes an adjustment state. In the adjustment state, the constraint member 1 and the constraint channel 21 are configured as follows:

[0088] The constraint member 1 is allowed to be fixed relative to the constraint channel 21 under the action of resistance, and the constraint segment 30 is at least partially circumferentially contracted.

[0089] When the constraint segment 30 is subjected to an expansion force, the constraint member 1 overcomes the resistance and moves relative to the constraint channel 21 to reduce the degree of circumferential contraction of the constraint segment 30.

[0090] When the circumferential contraction of the constraint segment 30 decreases, during the further expansion of the first working area 7 of the constraint segment 30, the portion of the constraint member 1 corresponding to the target area 8 of the constraint segment 30 is allowed to contract circumferentially, so that the target area 8 contracts. The first working area 7 and the target area 8 are adjacent areas on the constraint segment 30.

[0091] In this embodiment, the intravascular prosthesis can be as follows: Figure 1 The artificial blood vessel shown can also be a bulb-expandable cutting stent or, as... Figure 2 The self-expanding stent shown can be any combination of the three components. The intravascular prosthesis mainly comprises a tubular body 3, a first membrane layer 2, and a restraint element 1. When the tubular body 3 is an elastic artificial blood vessel or a self-expanding stent, it can self-expand to its natural state, i.e., its maximum designed diameter, without applying a restraint force. In this state, the self-expansion force of the tubular body 3 is relatively small. Before delivery, the tubular body 3 needs to be contracted to reduce its diameter, thereby facilitating its insertion into blood vessels or other tissues. In this invention, the tubular body 3 is preferably a self-expanding stent.

[0092] In this embodiment, as Figure 1 and Figure 2 As shown, a first membrane layer 2 is disposed on the tubular body 3. The first membrane layer 2 is attached to the tubular body 3 and is extensible, meaning that the first membrane layer 2 can expand as the tubular body 3 expands. When the intravascular prosthesis is an artificial blood vessel, the tubular body 3 has a cavity for blood flow, which allows blood to flow after implantation. When the intravascular prosthesis is a self-expanding stent, the tubular body 3 forms a cavity for blood flow after the first membrane layer 2 is disposed.

[0093] In some embodiments, the first membrane layer 2 may be made of expanded PTFE and attached to the tubular body 3 via hot pressing, bonding, or other processes. The first membrane layer 2 may completely cover the tubular body 3 or only a portion thereof, but it must at least cover the middle portion of the tubular body 3. In some embodiments, the elongation of the first membrane layer 2 is greater than 50%. In some embodiments, the elongation of the first membrane layer 2 is greater than 80%. In some embodiments, the elongation of the first membrane layer 2 is greater than 100%.

[0094] A constraint channel 21 is provided in the first membrane layer 2. The constraint channel 21 is spirally wound around the tubular body 3 and is a closed structure in the circumferential direction. A constraint member 1 is provided inside the constraint channel 21. The constraint member 1 is arranged along the direction of the constraint channel 21, that is, the constraint member 1 is also spirally wound around the tubular body 3. The part of the tubular body 3 corresponding to the constraint member 1 is the constraint segment 30. There is resistance between the constraint member 1 and the constraint channel 21. When the constraint member 1 is completely located inside the constraint channel 21, the resistance is the frictional resistance between the constraint member 1 and the constraint channel 21. By designing the constraint member 1 and the constraint channel 21, the resistance between the constraint member 1 and the constraint channel 21 can be made greater than the self-expansion force of the constraint segment 30, thereby constraining the constraint segment 30 to a specific diameter.

[0095] Intravascular prostheses are as follows Figure 2 Taking the self-expanding stent shown as an example, in this embodiment, the constraint segment 30 includes an initial state and an adjustment state. The initial state refers to the state of the constraint segment 30 when the constraint member 1 is spirally wound around the constraint channel 21 and the constraint segment 30 is circumferentially contracted, and the intravascular prosthesis is loaded into the delivery device as a whole. The adjustment state refers to the state of the constraint segment 30 under the action of the self-expansion force and the constraint force of the constraint member 1 when the delivery device releases the intravascular prosthesis to the lesion site, i.e., as shown in the figure. Figure 3 The state shown is such that the constraint segment 30 is in its initial adjustment state. In this initial adjustment state, the diameter of the constraint segment 30 can be increased by applying an expansion force to it.

[0096] In some implementations, such as Figure 3As shown, the constraint segment 30 in its initial adjustment state includes a first end 301, a second end 303, and a first central portion 302 located between the first end 301 and the second end 303. The first end 301 and the second end 303 gradually taper outward to a first diameter, while the first central portion 302 remains within a second diameter, the first diameter being larger than the second diameter. When the constraint segment 30 is in its initial adjustment state, the smaller diameter of the first central portion 302 increases the pressure differential when it is in a blood vessel. In this state, the constraint member 1 is relatively fixed to the constraint channel 21, and the resistance between the constraint member 1 and the constraint channel 21 provides a constraint force to the constraint segment 30, keeping each part of the constraint segment 30 within a set diameter. Of course, in other embodiments, the first diameter may also be equal to the second diameter.

[0097] When it is necessary to further increase the diameter of the constraint section 30, a device capable of applying an expansion force to the constraint section can be introduced into the constraint section 30 (for example, a non-compliant balloon catheter can be introduced into the constraint section 30). When an expansion force from the inside to the outside is applied to the constraint section 30 of the tubular body 3 by means of a balloon type 6 device, the constraint member 1 moves relative to the first membrane layer 2, that is, moves relative to the constraint channel 21 under the action of the expansion force.

[0098] In some embodiments, when an expansion force is applied to the central region of the constraint segment 30 through the balloon 6, the two ends of the constraint member 1 move relative to the first membrane layer 2 and move closer to each other. At this time, the diameter of the spiral structure formed by the constraint member 1 increases, and the constraint segment 30 and the first membrane layer 2 expand. The amount of expansion matches the amount of diameter increase of each turn on the constraint member 1.

[0099] Because the constraint member 1 remains within the constraint channel 21 during this process, and the self-expansion force of the constraint segment 30 gradually decreases as it expands, the constraint member 1, in conjunction with the constraint channel 21, can still constrain the constraint segment 30. Therefore, when the balloon 6 stops applying expansion force to the constraint segment 30, the constraint segment 30 will remain in its current state. In other words, before the constraint segment 30 reaches its maximum designed diameter, the constraint member 1 and the first membrane layer 2 can maintain the constraint segment 30 in an adjustable state of any degree of contraction, meaning the expansion degree of the constraint segment 30 is controllable. This solves the technical problem in related technologies where the specific degree of expansion of intravascular prostheses cannot be controlled during expansion.

[0100] Since the constraint segment 30 needs to be kept in the adjusted state by the resistance between the constraint member 1 and the constraint channel 21, the constraint member 1 should be made of a material with low elongation. Simultaneously, the surface friction coefficient of the constraint member 1 should be determined based on the self-expansion force of the constraint segment 30, ensuring that the resistance between the constraint member 1 and the constraint channel 21 is sufficient to keep the constraint segment 30 in the adjusted state. It is understood that the higher the surface friction coefficient of the constraint member 1, the greater the resistance between the constraint member 1 and the constraint channel 21. Because the constraint member 1 will be stretched and move within the constraint channel 21 during the expansion process, the greater the resistance, the greater the tensile force on the constraint member 1. Therefore, the overall tensile strength of the constraint member 1 should be sufficient to prevent breakage under this tensile force.

[0101] Therefore, in this embodiment, the constraint member 1 should be selected with a surface friction coefficient that precisely satisfies the requirement of keeping the constraint segment 30 in the adjusted state, while the tensile strength of the constraint member 1 should be sufficient to prevent it from being stretched or breaking when moved under the current frictional resistance. Based on this, in some embodiments, the constraint member 1 may be made of PTFE material.

[0102] like Figure 4 As shown, when the constraint segment 30 is in this adjusted state, the constraint segment 30 can be divided into multiple regions. In some embodiments, the constraint segment 30 includes an adjacent first working area 7 and a target area 8, and the axial lengths of the first working area 7 and the target area 8 are not limited here. Based on the division of the first working area 7 and the target area 8, the first membrane layer 2 can be divided into a first membrane segment and a second membrane segment (not shown in the figure), and the constraint member 1 can be divided into a first constraint segment 102 and a second constraint segment 103, wherein the first working area 7, the first membrane segment, and the first constraint segment 102 correspond. The target area 8, the second membrane segment, and the second constraint segment 103 correspond.

[0103] At this time, as Figure 5 As shown, an expansion force can be applied to the first working area 7 via the balloon 6. Under the action of this expansion force, the first working area 7 further expands, its diameter increases, and the constraint channel 21 in the first membrane segment further deforms and squeezes the first constraint segment 102. At this time, the frictional resistance between the first constraint segment 102 and the constraint channel 21 in the first membrane segment will be greater than the frictional resistance between the constraint channel 21 in the second membrane segment and the second constraint segment 103. As the diameter of the first working area increases, the diameter of the spiral structure formed by the first constraint segment also needs to increase. Therefore, the first constraint segment 102 will pull the second constraint segment 103 to tighten in the circumferential direction, thereby reducing the diameter of the target area 8, causing the target area 8 to be contracted, and realizing the reversible adjustment of the diameter of the target area 8.

[0104] It should be noted that the above process of reducing the diameter of the target area 8 is as follows: Figure 4The adjustment state shown is the basis. When the constraint segment 30 is in an adjustment state with other diameters, the target area 8 can still be reduced in the above manner. However, before reduction, the constraint segment 30 should be in a state where the degree of circumferential contraction is reduced compared to the initial adjustment state, that is, the diameter of the target area 8 on the constraint segment 30 needs to be larger than the diameter of the target area 8 when it is in the initial adjustment state.

[0105] In some embodiments, to facilitate the contraction of the target area 8 of the constraint segment 30, the axial length of the first working area 7 can be one-quarter to one-third of the axial length of the constraint segment 30, and the axial length of the target area 8 can be one-quarter to one-third of the axial length of the constraint segment 30. After this division, the constraint segment 30 also includes a region with a length of one-third to one-half (i.e., as shown in the image). Figure 4 As shown in the second working area 9, due to the force transmission on the constraint member 1, this area is farther away from the first working area 7. The part of the constraint member 1 in this area is also farther away from the first working area 7. The tensile force of the first constraint segment 102 will be concentrated on the second constraint segment 103, making the second constraint segment 103 easier to tighten, thereby making it easier to shrink the target area 8.

[0106] like Figure 3 As shown, the effective length of the balloon 6 is less than the length of the constraint segment 30, and it acts at least in the middle region of the constraint segment 30. The expansion of the balloon 6 can pull the two ends of the constraint member 1 towards the middle, thereby increasing the diameter of the constraint member 1, while the constraint segment 30 is expanded to the target diameter.

[0107] To facilitate shrinking of target area 8 in a visual environment, such as Figure 3 and Figure 4 As shown, in this embodiment, the target area 8 of the constraint segment 30 is provided with developing points 5. The developing points 5 can be developing material attached to the constraint segment 30.

[0108] In one embodiment, such as Figures 2 to 4 As shown, the constraint member 1 includes a connector 100 and at least two locking members 101, with the two locking members 101 located at both ends of the connector 100. The connector 100 is located in the constraint channel 21 and is spirally wound. The target area 8 is located between the locking members 101 at both ends, with one of the locking members 101 located in the first working area 7. The size of the locking member 101 is larger than the size of the constraint channel 21, and the locking member 101 is configured to be able to keep the constraint section 30 in an adjustable state through a resistance engagement with the constraint channel 21.

[0109] When the constraint segment 30 is subjected to an expansion force in the adjusted state to reduce the circumferential contraction of the constraint segment 30, the locking piece 101 can overcome the resistance of the constraint channel 21 and move within the constraint channel 21.

[0110] During the further expansion of the first work area 7, the card 101 located in the first work area 7 is fixed.

[0111] Specifically, in one embodiment, a film can be first applied to the tubular body 3 in its natural state, then the connector 100 can be spirally wound onto the film, and then another film can be applied, forming an opening 20 through which the connector 100 passes on the second film. The portion of the two films outside the connector 100 is connected together during the film application process, and the two films together form the first film layer 2, which accommodates the connector 100, i.e., the constraint channel 21. At this time, by pulling the two ends of the connector 100 extending through the opening 20, the portion of the tubular body 3 wrapped with the connector 100 can be contracted (i.e., the constraint section 30 contracts) to the point where... Figure 3 The initial adjustment state or a target state with a diameter smaller than that adjustment state is shown. Then, clamps 101 are set at both ends of the connector 100. The size of the clamps 101 is larger than the size of the constraint channel 21. The constraint segment 30 is constrained in the initial adjustment state or the target state by the resistance cooperation between the clamps 101 and the constraint channel 21.

[0112] Additionally, it should be noted that when constraint segment 30 is shrunk to, for example... Figure 3 When the diameter is smaller in the adjusted state shown, there can be a distance between the locking member 101 and the first membrane layer 2. After the locking member 101 is set, it is released and expands under the self-expansion force of the constraint section 30. The locking member 101 is pulled to abut against the opening 20 of the first membrane layer 2. At this time, the constraint section 30 is in the position shown. Figure 3 The adjustment state shown is maintained by the clamp 101 abutting against the opening 20, thus keeping the constraint section 30 in this adjustment state.

[0113] Of course, the clip 101 can also be pulled through the opening 20 into the constraint channel 21, and the constraint section 30 is kept in the initial adjustment state by the frictional resistance between the clip 101 and the constraint channel 21.

[0114] In this embodiment, the constraint segment 30 is kept in the adjusted state by the resistance between the constraint member 1 and the constraint channel 21, specifically by the resistance between the locking member 101, the connecting member 100, and the constraint channel 21. Since the connecting member 100 is spirally arranged within the constraint channel 21, the frictional resistance between its two ends and the constraint channel 21 is small. When the locking member 101 is not provided, the two ends of the connecting member 100 cannot effectively constrain the two ends of the constraint segment 30 by their own frictional resistance, ultimately leading to the failure of the overall constraint on the constraint segment 30. However, after the locking member 101 is provided, because the size of the locking member 101 is larger than the size of the constraint channel 21 (for example, the cross-sectional size of the locking member 101 is larger than the cross-sectional size of the constraint channel 21), there is greater resistance between the locking member 101 and the constraint channel 21, thereby enabling the constraint segment 30 to be kept in the adjusted state.

[0115] Of course, the size of the clip 101 cannot be set too large. It needs to be able to overcome the resistance of the constraint channel 21 and move within the constraint channel 21 when the constraint segment 30 is subjected to an expansion force in the adjusted state to reduce the circumferential contraction of the constraint segment 30. It can be understood that the constraint channel 21 has a first membrane layer 2 formed thereon. The first membrane layer 2 is extensible. When subjected to external force, the size of the constraint channel 21 can be expanded, so that the clip 101 can move within the constraint channel 21 by squeezing and expanding the constraint channel 21.

[0116] Based on this, in this embodiment, the locking pieces 101 are located at both ends of the constraint segment 30, and the target area 8 on the constraint segment 30 is located between the locking pieces 101 at both ends. For example, the target area 8 is located in the middle of the constraint segment 30, and one of the locking pieces 101 is located in the first working area 7. When the first working area 7 is directly subjected to an expansion force and further expands, the part of the constraint channel 21 corresponding to the first working area 7 will squeeze the locking piece 101 located in the first working area 7. At this time, the locking piece 101 will be fixed as an anchor point. As the first working area 7 expands, it pulls the connecting piece 100 located in the target area 8 to contract, causing the target area 8 to contract and achieving the purpose of reducing the diameter of the target area 8.

[0117] Therefore, it can be seen that the setting of the card 101 in this embodiment can not only keep the constraint segment 30 in the adjustment state, but also, when the target area 8 of the constraint segment 30 shrinks, pull the connector 100 of the target area 8 to shrink, thus ensuring that the shrinkage of the target area 8 is smooth.

[0118] When the locking member 101 abuts against the opening 20, placing the constraint section 30 in its initial adjustment state, during the further expansion of the constraint section 30, the locking member 101 needs to open the opening 20 and enter the constraint channel 21. Therefore, to facilitate the locking member 101 opening the opening 20, the locking member 101 includes a tapered portion. When the constraint section 30 is in its initial adjustment state, the smaller diameter section of the tapered portion passes through the opening 20 and is located within the constraint channel 21, while the larger diameter section of the tapered portion is located outside the opening 20 and abuts against it. In this embodiment, the tapered portion guides the locking member 101 to open the opening 20 and enter the constraint channel 21, which is beneficial for the stable expansion of the constraint section 30.

[0119] In some embodiments, the clip 101 may be a knot or similar structure disposed at both ends of the connector 100, and its size is slightly larger than that of the connector 100. The connector 100 may be a cylindrical flexible wire, a flat flexible wire, or a combination of multiple flat flexible wires stacked together.

[0120] Furthermore, when the constraint segment 30 is in an adjustment state with reduced circumferential contraction (i.e., a non-initial adjustment state), the locking pieces 101 at both ends of the connector 100 are located within the constraint channel, such as... Figure 4 As shown, the axial length of the first working area 7 can be one-third of the axial length of the constraint segment 30, and the locking piece 101 at the left end of the first constraint segment 102 corresponds to the first working area 7. At this time, when an expansion force is applied to the first working area 7, since the locking piece 101 at the right end is located in the constraint channel, it is farther away from the first working area 7 at the left end, and the frictional resistance between the locking piece 101 and the constraint channel per unit area is greater than the frictional resistance between the connecting piece 100 and the constraint channel 21, the locking piece 101 at the right end is not easy to move under the pull of the first constraint segment 102, so that the part of the connecting piece 100 near the first constraint segment 102 (i.e., the second constraint segment 103) can be more easily contracted, thereby contracting the part of the constraint segment 30 near the first working area 7 (i.e., the target area 8).

[0121] In one embodiment, such as Figure 6 and Figure 7 As shown, there are three clips 101, two of which are located at both ends of the connector 100, and the other clip 101 is located near the middle of the target area 8 of the constraint segment 30.

[0122] In this embodiment, there is a large frictional resistance between the locking piece 101 located near the middle and the constraint channel 21. When the balloon 6 applies an expansion force to the middle region of the constraint segment 30 (which corresponds to the locking piece near the middle of the connector 100), the locking piece 101 located near the middle acts as an anchor point to pull the locking pieces 101 at both ends into the constraint channel, thereby reducing the degree of contraction of the constraint segment 30.

[0123] Furthermore, with this configuration, when the constraint segment 30 is in a non-initial adjustment state, the locking piece 101, located near the center of the connector 100, is also located near the center of the constraint segment 30. Based on this, as... Figure 7 As shown, the constrained section 30 in the adjusted state can be divided into three regions: the first working area 7, the target area 8, and the second working area 9. The first working area 7 corresponds to the latch 101 at the left end of the connector 100, the target area 8 corresponds to the latch 101 near the middle of the connector 100 (where the developing point 5 of the target area 8 is located near this latch 101), and the second working area 9 corresponds to the latch 101 at the right end of the connector 100. When an expansion force is applied to the first working area 7, the target area 8 contracts. The second working area 9 also partially contracts under the pull of the connector 100, but the degree of contraction is less than that of the target area 8. Because the target area 8 has a corresponding latch 101, the latch 101, in conjunction with the constrained channel 21, provides greater frictional resistance to constrain the expansion of the target area 8 under its own expansion force.

[0124] Furthermore, after the target area 8 shrinks, based on the locking piece 101 near the middle of the connector 100 and the locking piece 101 at the right end of the connector 100, a new area division can be made for the corresponding part of the constraint segment 30. At this time, the part of the target area 8 that has not reached the maximum shrinkage degree can be taken as a new target area, and by applying an expansion force to the second working area 9, the new target area can be further shrunk. Alternatively, the part of the target area that has not reached the maximum shrinkage degree and the part of the second working area 9 that is close to the target area can be taken together as a new target area, and the rest of the second working area 9 can be taken as a new working area to be expanded. By applying an expansion force to this working area, the new target area can be further shrunk.

[0125] In one embodiment, when an intravascular prosthesis is used in a transjugular intrahepatic portal vein shunt, the intravascular prosthesis further includes a second membrane layer. This second membrane layer is extensible and is attached to the outside of the first membrane layer. In this embodiment, the second membrane layer ensures the circumferential sealing performance of the restraint segment, preventing blood from flowing out circumferentially through the restraint segment. It should be noted that the length of the second membrane layer can be greater than the length of the first membrane layer; the specific length is designed according to actual needs.

[0126] In one embodiment, such as Figure 3 As shown, the intravascular prosthesis is a self-expanding stent. Therefore, the constraint section 30 on the self-expanding stent includes multiple turns of wave ring 300. The connector 100 includes multiple turns of connecting segments 1000 connected end to end after spiral winding. Each turn of wave ring 300 is wound with at least one turn of connecting segment 1000.

[0127] In this embodiment, the constraint segment 30 includes multiple axially distributed wave rings 300. The contraction and expansion process of the constraint segment 30 is essentially the process of wave contraction and expansion within each wave ring 300. The spiral connector 100 includes multiple axially connected connecting segments 1000, each connecting segment 1000 being a short spiral structure. Therefore, to improve the constraint effect between the connector 100 and the various parts of the constraint segment 30, at least one connecting segment 1000 is wound around each wave ring 300; in other words, each wave ring 300 is constrained by at least one connecting segment 1000.

[0128] Based on the above embodiments, in order to better constrain the constraint segment 30, at least two connecting segments 1000 are wound around each waveform ring 300. The two connecting segments 1000 are respectively close to the peak and trough of the waveform ring 300 they constrain. That is, both ends of each waveform ring 300 can be subject to the constraint force of the corresponding connecting segment 1000, thereby keeping the constraint segment 30 in the corresponding adjustment state.

[0129] To prevent some connecting segments 1000 from detaching from the corresponding waveform ring 300 during expansion and contraction, in one embodiment, the intravascular prosthesis also includes an anti-detachment structure. The anti-detachment structure is at least connected between the connecting segments 1000 and the waveform ring 300 within the target area 8 of the restraint segment 30, thereby restricting the connecting segments 1000 in this area from detaching from the corresponding waveform ring 300.

[0130] In some implementations, the anti-detachment structure may be connected between each waveform ring 300 and each connecting segment 1000 on the constraint segment 30.

[0131] In one embodiment of the anti-detachment structure, such as Figure 8 As shown, the anti-detachment structure includes a first anti-detachment component 10, which is arranged along the axial direction of the constraint section 30. Both ends of the first anti-detachment component 10 are fixedly connected to the tubular body 3, and the length of the first anti-detachment component 10 is greater than or equal to the length of the constraint section 30.

[0132] In this embodiment, the first anti-detachment component 10 has a slender structure and can be attached to the inner side of the tubular body 3. Both ends of the first anti-detachment component 10 are fixed to both ends of the tubular body 3, with the fixing positions located at both ends of the constraint section 30. The fixing method can be welding, bolting, etc. To prevent the connecting segment 1000 from detaching from the waveform ring 300, the first anti-detachment component 10 is alternately inserted outside the connecting segment 1000 and inside the waveform ring 300 along the axial direction of the constraint section 30. For example, the waveform ring 300 is divided into A1, A2, A3... along the axial direction, and the connecting segment 1000 is divided into B1, B2, B3... along the axial direction. The insertion method of the first anti-detachment component 10 is: inserted outside B1—inserted inside A1—inserted outside B2—inserted inside A2—inserted outside B3—inserted inside A3... With this arrangement, it can prevent each connecting segment 1000 from detaching from the corresponding waveform ring 300 in the direction from B1 to B3.

[0133] In some embodiments, at least two first anti-detachment elements 10 are provided, and the two first anti-detachment elements 10 are symmetrically distributed, thereby restricting both sides of each connecting segment 1000. In some embodiments, such as Figure 8 As shown, the first anti-detachment component 10 can be configured in multiples and distributed at intervals along the circumference of the tubular body 3.

[0134] In the above embodiments, the first anti-detachment component 10 can limit the connecting segment 1000 from detaching from the corresponding waveform ring 300 in one direction. Based on this, to limit the connecting segment 1000 from detaching from the corresponding waveform ring 300 in another direction, such as... Figures 9 to 11 As shown, the first anti-detachment component 10 is provided with a sleeve structure 11, which is sleeved on at least the connecting segment 1000 and the waveform ring 300 of the target area 8 of the constraint segment 30.

[0135] In this embodiment, the first anti-detachment component 10 is provided with a sleeve structure 11. After the first anti-detachment component 10 is fixed, it is sleeved onto the corresponding waveform ring 300 and connecting segment 1000 through the sleeve structure 11, thereby ensuring that the relative positions of the connecting segment 1000 and each waveform ring 300 remain unchanged. The sleeve structure 11 can maintain a sliding connection with the connecting segment 1000, thereby satisfying the movement of the connecting segment 1000 during the expansion and contraction of the constraint segment 30.

[0136] In some embodiments, the socket structure 11 may be sleeved on each connecting segment 1000 and the waveform ring 300.

[0137] In one embodiment, such as Figure 11As shown, the first anti-detachment component 10 includes a flexible anti-detachment line. The two ends of the anti-detachment line are fixed to the portions of the tubular body 3 located at both ends of the constraint section 30. The anti-detachment line is knotted with at least the connecting segment 1000 of the target area 8 of the constraint section 30 and each waveform ring 300 to form a sleeve structure 11.

[0138] In some implementations, such as Figure 10 As shown, the sleeve structure 11 includes multiple collars, which are spaced apart along the axial direction of the first anti-detachment member. Specifically, during fabrication, the anti-detachment thread wraps around the connecting segment 1000 at least once, then wraps around itself two to three times before exiting to form the sleeve structure 11 on the connecting segment 1000. It then wraps around the crest of the corresponding waveform ring 300 once before exiting to form the sleeve structure 11 on the waveform ring 300. This process continues until the next connecting segment 100 is reached, where the thread continues to be wound in the same manner. In this embodiment, the sleeve structure 11 formed by the anti-detachment thread knotted in the above manner effectively restricts the relative position of the connecting segment 1000 and the waveform ring 300, and facilitates the movement of the connecting segment 1000.

[0139] In some embodiments, the anti-detachment thread is knotted with each connecting segment 1000 and each wave loop 300 to form a sleeve structure 11. In some embodiments, such as Figure 12 As shown, the anti-detachment structure includes a connecting ring 120, which is sleeved on at least two waists of the wave ring 300. A connecting segment 1000, wound around the wave ring 300, slides through the connecting ring 120. In some embodiments, such as... Figure 13 and Figure 14 As shown, the anti-detachment structure includes a cable sleeve 121, which is wound and fixed around at least two waists of the wave ring 300, and the connecting segment 1000 wound on the wave ring 300 slides through the cable sleeve 121.

[0140] In one embodiment, to prevent the connecting segment 1000 from detaching from the corresponding waveform ring 300, each turn of the connecting segment 1000 passes through at least one peak on the waveform ring 300 to which it is wound. Specifically, as... Figure 15 and Figure 16 As shown, each connecting segment 1000 of the connector needs to pass through at least one crest on the waveform ring 300 it constrains. In other words, when the connector 100 is wound spirally around the constraining segment 30, the connector 100 cannot simply pass through the outside of the constraining segment 30; for each turn of the waveform ring 300 of the constraining segment 30, the connector 100 needs to pass through at least one crest on each turn of the waveform ring 300, thereby preventing each connecting segment 1000 on the connector 100 from detaching from the corresponding waveform ring 300.

[0141] In a preferred embodiment, each connecting segment 1000 can sequentially pass through all the peaks of each waveform ring 300, thereby better preventing the connecting segment 1000 from detaching.

[0142] Based on the above embodiments, such as Figure 17 As shown, in order to better constrain the constraint segment 30, there are two connecting segments 1000 on each waveform ring 300. The two connecting segments 1000 pass through the crest and trough of the waveform ring 300 respectively, thus constraining both ends of each waveform ring 300.

[0143] As can be seen from the above embodiments, the constraint segment 30 is in an initial adjustment state before being loaded into the conveyor. When the target diameter of the constraint segment 30 in the initial adjustment state is small, it is difficult to shrink the constraint segment 30 to the target diameter by pulling the two ends of the connector 100. Therefore, in this embodiment, a sleeve 13 is provided to assist the constraint segment 30 in shrinking to the initial adjustment state.

[0144] Specifically, such as Figure 18 As shown, the intravascular prosthesis in this embodiment also includes a cannula 13. The cannula 13 is extensible, and its inner diameter is the same as the outer diameter of the restraint segment 30 in the initial adjustment state. The cannula 13 is used to fit over the restraint segment 30 when the restraint segment 30 shrinks to the target loading diameter due to external restraint force. After the external restraint force is removed, the restraint segment 30 expands to fit with the cannula 13 and is in the initial adjustment state. When the restraint segment 30 is subjected to expansion force, it can overcome the restraint force of the cannula 13 to change the degree of contraction.

[0145] Specifically, such as Figure 19 As shown, in this embodiment, the sleeve 13 is a pre-prepared tubular structure, the shape of which is similar to that of the constraint section 30 in its initial adjustment state, and its inner diameter is equal to the outer diameter of the constraint section 30 in its initial adjustment state. Figure 18 As shown, assuming the target diameter of the constraint segment 30 in its initial adjustment state is D2, after the first membrane layer 2 and the constraint member 1 are installed on the constraint segment 30, the constraint segment 30 is contracted to a diameter of D1 by pulling both ends of the constraint member 1, where D1 is greater than D2. Then, as... Figure 20 As shown, the tubular body 3 is fitted onto the sheath core. The tubular body 3 is then contracted to a diameter of D3 using the loading fixture 14, where D3 is less than D1. The outer diameter of the loading fixture 14 is less than or equal to D2 and greater than D3. Then, as shown... Figure 21 As shown, sleeve 13 is fitted over the loading fixture 14, with the inner diameter of sleeve 13 equal to D2. Then, the loading fixture 14 is removed. Figure 22 As shown, the constraint section 30 expands to fit against the inner surface of the sleeve 13. At this time, the diameter of the constraint section 30 is D2, which is the target diameter.

[0146] In this embodiment, the sleeve 13 facilitates the contraction of the constrained section 30 to a smaller target diameter. When the constrained section 30 is at the target diameter (i.e., in the initial adjustment state), after applying an expansion force to the constrained section 30, the constrained section 30 overcomes the binding force of the sleeve 13, the resistance between the constrained member 1 and the constrained channel 21, and the binding force of the first membrane layer 2, thus expanding. Simultaneously, the sleeve 13 also expands. In this embodiment, the sleeve 13 can be a multilayer membrane composite structure with high elongation performance, such as using ePTFE or similar materials.

[0147] In some implementations, in the initial adjustment state, such as Figure 18 As shown, the constraint segment 30 includes a first end 301, a second end 303, and a first central portion 302 located between the first end 301 and the second end 303. The first end 301 and the second end 303 gradually taper outward to a first diameter, while the first central portion 302 remains within a second diameter. The first diameter is larger than the second diameter. In this embodiment, as... Figure 19 As shown, the sleeve 13 also has a structure corresponding to the first end 301, the second end 303, and the first central portion 302. In the initial adjustment state, as... Figure 22 As shown, the sleeve 13 fits tightly against the first end 301, the second end 303, and the first central portion 302. Of course, in other embodiments, the first diameter may also be equal to the second diameter.

[0148] In one embodiment, such as Figure 23 As shown, a sleeve constraint member 15 is provided inside the sleeve 13. The sleeve constraint member 15 is spirally wound around the circumference of the sleeve 13, and the pitch and spiral angle are consistent with the waveform rings. This allows the sleeve constraint member 15 to constrain each waveform ring 300 of the constraint section 30 after the sleeve 13 is fitted onto the constraint section 30. In the adjusted state, the sleeve constraint member 15 and the sleeve 13 are relatively fixed by resistance. The sleeve constraint member 15 is configured to overcome the resistance and move within the sleeve 13.

[0149] In this embodiment, the tight fit between the sleeve constraint member 15 and the sleeve 13 provides constraint force to the constraint section 30, reducing the need for constraint force on the sleeve 13 itself. When the constraint section 30 expands, the sleeve 13 expands synchronously, and the diameter of the spiral structure formed by the sleeve constraint member 15 within the sleeve 13 increases while the number of turns decreases. In this embodiment, the sleeve constraint member 15 can be a flexible wire.

[0150] In some implementations, such as Figure 24As shown, the sleeve constraint 15 can be a relatively long linear structure that covers the entire sleeve 13 after spiral winding. In some embodiments, as shown in 24, the sleeve constraint 15 can also be a shorter linear structure, with multiple sleeve constraint members 15 spaced apart to form a discontinuous spiral winding structure that covers the entire sleeve 13. In some embodiments, the ends of adjacent sleeve constraint members 15 are joined circumferentially or superimposed axially.

[0151] In one embodiment, such as Figure 26 As shown, the constraint member 1 is configured as two or more spaced segments, so that the tubular body 3 forms two or more constraint segments 30. Each constraint segment 30 on the tubular body 3 can expand and contract as described in the above embodiment, which will not be elaborated here. After setting multiple constraint segments 30, the expansion and contraction control of the constraint segments 30 is more precise and flexible, and the length and number of constraint segments 30 can be designed according to actual needs.

[0152] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An intravascular prosthesis, characterized in that, include: Tubular body; A first membrane layer is attached to the tubular body. The first membrane layer is extensible and has a constraint channel provided therein. The constraint channel extends in a spiral shape along the circumference of the tubular body. A constraint member, at least a portion of which is disposed within the constraint channel and spirally wound around the tubular body; The portion of the tubular body corresponding to the constraint member is a constraint segment, which includes an adjustment state. In the adjustment state, the constraint member and the constraint channel are configured as follows: The constraint member is allowed to be fixed relative to the constraint channel under the action of resistance, and the constraint segment is at least partially circumferentially contracted. When the constraint segment is subjected to an expansion force, the constraint member overcomes the resistance and moves relative to the constraint channel to reduce the degree of circumferential contraction of the constraint segment; When the circumferential contraction of the constraint segment decreases, during the further expansion of the first working area of ​​the constraint segment, the portion of the constraint member corresponding to the target area of ​​the constraint segment is allowed to contract circumferentially, so that the target area is contracted. The first working area and the target area are adjacent areas on the constraint segment.

2. The intravascular prosthesis according to claim 1, characterized in that, The constraint member includes a connector and at least two locking members, with the two locking members located at both ends of the connector, and the connector located in the constraint channel and spirally wound. The target area is located between the two card pieces at both ends, with one of the card pieces located in the first working area; The size of the card is larger than the size of the constraint channel, and the card is configured as follows: It can maintain the constraint segment in the adjusted state through resistance engagement with the constraint channel; When the constraint segment is subjected to an expansion force in the adjusted state to reduce the circumferential contraction of the constraint segment, the locking element can overcome the resistance of the constraint channel and move within the constraint channel; During the further expansion of the first work area, the card located within the first work area is fixed.

3. The intravascular prosthesis according to claim 2, characterized in that, The first membrane layer has two openings, which are connected to the constraint channel; When the constraint segment is in its initial adjustment state, at least a portion of the locking member is located outside the opening and abuts against the opening. The locking member is configured to open the opening and enter the constraint channel when the constraint segment is subjected to an expansion force.

4. The intravascular prosthesis according to claim 3, characterized in that, The clip includes a tapered portion. When the constraint section is in the initial adjustment state, the small diameter section of the tapered portion is located inside the constraint channel, and the large diameter section of the tapered portion is located outside the opening and abuts against the opening.

5. The intravascular prosthesis according to claim 2, characterized in that, When the constraint segment is in its initial adjustment state, the card is completely located within the constraint channel.

6. The intravascular prosthesis according to claim 2, characterized in that, The cross-section of the connector is circular or polygonal.

7. The intravascular prosthesis according to claim 2, characterized in that, The target area of ​​the constrained segment is provided with developing points.

8. The intravascular prosthesis according to claim 2, characterized in that, The card is configured as three, with two of the card located at both ends of the connector and the other card located near the middle of the target area of ​​the constraint segment.

9. The intravascular prosthesis according to claim 8, characterized in that, When the constraint section is in the adjustment state, the clip located near the middle of the connector is close to the developing point.

10. The intravascular prosthesis according to claim 1, characterized in that, It also includes a second film layer, which is stretchable and is attached to the outside of the first film layer.

11. The intravascular prosthesis according to claim 2, characterized in that, The constraint segment includes multiple turns of a waveform ring, and the connector includes multiple turns of a connecting segment connected end to end, with each turn of the waveform ring wrapping around at least one turn of the connecting segment.

12. The intravascular prosthesis according to claim 11, characterized in that, Each loop of the waveform ring has at least two loops of the connecting segment wrapped around it, with the two loops of the connecting segment respectively close to the crest and trough of the waveform ring it constrains.

13. The intravascular prosthesis according to claim 11, characterized in that, It also includes an anti-detachment structure, which is at least connected between the connecting segment and the waveform ring in the target area of ​​the constraint segment, thereby preventing the connecting segment from detaching from the waveform ring it is wrapped with.

14. The intravascular prosthesis according to claim 13, characterized in that, The anti-detachment structure includes a first anti-detachment component, which is arranged along the axial direction of the tubular body. Both ends of the first anti-detachment component are fixedly connected to the portions of the tubular body located at both ends of the constraint section. The length of the first anti-detachment component is greater than or equal to the length of the constraint section. Along the axial direction of the constraint section, the first anti-detachment component is alternately inserted outside the connecting segment and inside the wave ring.

15. The intravascular prosthesis according to claim 14, characterized in that, The first anti-detachment component is provided in at least two parts, and the two first anti-detachment components are symmetrically distributed.

16. The intravascular prosthesis according to claim 14, characterized in that, The first anti-detachment component is provided with a sleeve structure, which is sleeved on at least the connecting segment and the waveform ring of the target area of ​​the constraint segment.

17. The intravascular prosthesis according to claim 16, characterized in that, The first anti-detachment component includes a flexible anti-detachment line, the two ends of which are fixed to portions of the tubular body located at the ends of the constraint section. The anti-detachment line is at least knotted with the connecting segment and the wave ring in the target area of ​​the constraint section to form the sleeve structure; or The sleeve structure includes multiple collars, which are spaced apart along the axial direction of the first anti-detachment component.

18. The intravascular prosthesis according to claim 13, characterized in that, The anti-detachment structure includes a connecting ring, which is sleeved on at least two waists of the wave ring, and the connecting segment wrapped around the wave ring slides through the connecting ring.

19. The intravascular prosthesis according to claim 13, characterized in that, The anti-detachment structure includes a sleeve, which is wound and fixed around at least two waists of the wave ring, and the connecting segment wound on the wave ring slides through the sleeve.

20. The intravascular prosthesis according to claim 11, characterized in that, Each turn of the connecting segment passes through at least one peak on the waveform loop it is wrapped around.

21. The intravascular prosthesis according to claim 20, characterized in that, Each of the waveform rings has at least two turns of the connecting segment wound around it, and the two turns of the connecting segment pass through the crest and trough of the waveform ring around which it is wound.

22. The intravascular prosthesis according to claim 1, characterized in that, It also includes a sleeve, which is extensible, and the inner diameter of the sleeve is the same as the outer diameter of the constraint section in the initial adjustment state. The sleeve is used to fit over the constraint section when the constraint section shrinks to the target loading diameter due to the external constraint force, and the constraint section expands to fit the sleeve after the external constraint force is removed. When the constrained section is subjected to an expansion force, it can overcome the constraint force of the sleeve to change the degree of contraction.

23. The intravascular prosthesis according to claim 22, characterized in that, In the initial adjustment state, the constraint segment includes a first end, a second end, and a first central portion located between the first end and the second end. The first end and the second end gradually taper outward to a first diameter, and the first central portion remains at a second diameter. The first diameter is greater than or equal to the second diameter. In the initial adjustment state, the sleeve fits tightly against the first end, the second end, and the first central portion.

24. The intravascular prosthesis according to claim 22, characterized in that, A sleeve constraint member is provided inside the sleeve, and the sleeve constraint member is spirally wound around the circumference of the sleeve. The sleeve constraint member is configured to overcome resistance and move within the sleeve. In the adjusted state, the sleeve constraint member and the sleeve are relatively fixed by resistance.

25. The intravascular prosthesis according to claim 24, characterized in that, The sleeve constraint members are configured in multiple ways, and the multiple sleeve constraint members are distributed at intervals to form a discontinuous helical winding structure; or, The ends of adjacent sleeve constraint members are joined together circumferentially or superimposed axially.

26. The intravascular prosthesis according to claim 1, characterized in that, The constraint element is configured as two or more spaced segments, so that the tubular body forms two or more constraint segments.

Images