Stent with plaque capturing net

Abstract

A medical stent includes an expandable structure movable between a contracted configuration for delivery and an expanded configuration for deployment, the expandable structure in the expanded configuration defining a relaxed diameter. The expandable structure maintains its relaxed diameter along portions of the expandable structure that are not constrained by contact with the vessel wall after deployment. The portions of the expandable structure that are compressed in contact with the vessel wall after deployment move to reduced diameters that are smaller than relaxed diameters along these portions. The compressed portion of the expandable structure may help prevent plaque loosening. An uncompressed portion of the expandable structure may allow blood to flow through.

Description

Cross-references to related applications

[0001] This application claims the benefit of US Provisional Patent Application No. 63 / 534,616, filed August 25, 2023, the disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to methods and devices for various digestive system diseases. More specifically, this disclosure relates to different constructions and methods for manufacturing and using stents. Background Technology

[0003] Implantable stents are devices placed in body structures (such as blood vessels, esophagus, trachea, bile ducts, colon, intestines, stomach, or body cavities) to provide support and maintain patency. These devices are manufactured using any of a variety of different methods and can be used for a variety of applications depending on the method used. Each of the known medical devices, delivery systems, and methods has its own advantages and disadvantages. There has always been a need for alternative medical devices and delivery devices, as well as alternative methods for manufacturing and using them. Summary of the Invention

[0004] This disclosure relates to several alternative designs, materials, and methods for manufacturing structures and components of medical devices, and their uses.

[0005] An example can be seen in a medical stent. This medical stent includes an expandable structure that is movable between a contractile configuration for delivery and an expandable configuration for deployment, the expandable structure in the expandable configuration defining a relaxed outer diameter. The expandable structure maintains its relaxed outer diameter along a portion of the expandable structure that is not constrained by contact with the vessel wall after deployment. The expandable structure moves along a portion of the expandable structure that is compressed after deployment and comes into contact with the vessel wall to a reduced outer diameter smaller than the relaxed outer diameter.

[0006] Alternatively or additionally, the expandable structure may define a plurality of voids through the walls of the expandable structure, and the voids have a first average size when the expandable structure is maintained in its relaxed configuration, and the voids have a second average size smaller than the first average size when the expandable structure is compressed to the reduced outer diameter.

[0007] Alternatively or additionally, the expandable structure may include an inner layer and an outer layer movable relative to the inner layer, wherein the outer layer is spaced apart from the inner layer by a first distance when the expandable structure maintains its relaxed outer diameter, and the outer layer is spaced apart from the inner layer by a second distance when the expandable structure is compressed to a reduced outer diameter. The second distance is smaller than the first distance.

[0008] Alternatively or additionally, the expandable structure may include a knitted support.

[0009] Alternatively or additionally, the knitted scaffold may include a plurality of loops, at least some of which have a relaxed configuration in which the loops extend radially outward relative to the longitudinal axis of the medical scaffold.

[0010] Alternatively or additionally, the ring, which extends radially outward relative to the longitudinal axis of the medical stent, may be adapted to fold when compressed due to contact with the vessel wall.

[0011] Alternatively or additionally, a ring having the relaxation configuration may define the relaxation outer diameter of the expandable structure, in which the ring extends radially outward.

[0012] Alternatively or additionally, when the ring is folded, the ring, which is adapted to fold upon compression, may define the reduced outer diameter of the expandable structure.

[0013] Alternatively or additionally, the expandable structure may comprise one or more elongated struts and one or more filaments wound around each of the one or more elongated struts. The one or more filaments form a coil with a relaxed configuration that defines the relaxed outer diameter of the expandable structure, and portions of the coil compressed due to contact with the blood vessel wall define the reduced outer diameter of the expandable structure.

[0014] Another example can be seen in medical stents. The medical stent includes: a tubular substrate extending from a proximal end to a distal end, the tubular substrate being movable between a radially contracting configuration and a radially expanding configuration; and a compliance layer extending over at least a portion of the tubular substrate, the compliance layer having a relaxed thickness when not radially constrained, the compliance layer being adapted to radially compress to a reduced thickness when radially constrained.

[0015] Alternatively or additionally, the compliance layer may include a plurality of rings, at least some of which have a relaxed configuration in which the rings extend radially outward relative to the longitudinal axis of the medical stent.

[0016] Alternatively or additionally, the ring, which extends radially outward relative to the longitudinal axis of the medical stent, may be adapted to fold when compressed upon contact with the vessel wall.

[0017] Alternatively or additionally, a ring having the relaxation configuration may define the relaxation thickness of the compliant layer, in which the ring extends radially outward.

[0018] Alternatively or additionally, the ring, which is adapted to fold when compressed, may define the reduced thickness of the compliant layer when folded.

[0019] Another example can be seen in medical stents adapted for deployment within a blood vessel having lateral branches extending from the vessel, the stent being adapted to be deployed within the blood vessel at a location crossing the lateral branches. The medical stent includes: a substrate extending from a proximal end to a distal end, the substrate defining a tubular body movable between a radially contractile configuration and a radially dilatant configuration; and a compliance layer extending over at least a portion of the substrate, the compliance layer being adapted to contact the vessel wall of the blood vessel and be radially compressed. A first portion of the compliance layer is configured to contact the vessel wall and be radially compressed when deployed within the blood vessel, and a second portion of the compliance layer corresponding to the location of the lateral branch extension is configured not to be radially compressed or to be compressed less than the first portion when deployed within the blood vessel.

[0020] Another example can be seen in medical stents. This medical stent includes an expandable structure capable of moving between a contractile configuration for delivery and an expandable configuration for deployment, the expandable structure in the expandable configuration defining a relaxed outer diameter. After deployment, portions of the expandable structure not constrained by contact with the vessel wall retain their relaxed outer diameter, and portions of the expandable structure compressed upon contact with the vessel wall after deployment move to a reduced outer diameter smaller than the relaxed outer diameter.

[0021] Alternatively or additionally, the expandable structure defines a plurality of voids through the walls of the expandable structure. When the expandable structure maintains its relaxed configuration, the voids have a first average size, and when the expandable structure is compressed to the reduced outer diameter, the voids have a second average size smaller than the first average size.

[0022] Alternatively or additionally, the expandable structure may include an inner layer and an outer layer movable relative to the inner layer to change the wall thickness of the expandable structure. When the expandable structure maintains its relaxed outer diameter, the outer layer is spaced apart from the inner layer by a first distance; and when the expandable structure is compressed to a reduced outer diameter, the outer layer is spaced apart from the inner layer by a second distance. The second distance is smaller than the first distance.

[0023] Alternatively or additionally, the expandable structure may include a knitted support.

[0024] Alternatively or additionally, the knitted scaffold may include a plurality of loops, at least some of which have a relaxed configuration in which the loops extend radially outward relative to the longitudinal axis of the medical scaffold.

[0025] Alternatively or additionally, the ring extending radially outward relative to the longitudinal axis of the medical stent may be adapted to fold when compressed due to contact with the vessel wall, thereby reducing the wall thickness of the expandable structure.

[0026] Alternatively or additionally, a ring having the relaxation configuration may define the relaxation outer diameter of the expandable structure, in which the ring extends radially outward.

[0027] Alternatively or additionally, when the ring is folded, the ring, which is adapted to fold when compressed, can define the reduced outer diameter of the expandable structure, thereby reducing the wall thickness of the expandable structure.

[0028] Alternatively or additionally, the expandable structure may comprise one or more elongated struts and one or more filaments wound around each of the one or more elongated struts. The one or more filaments form a coil with a relaxed configuration that defines the relaxed outer diameter of the expandable structure. A portion of the coil compressed due to contact with the blood vessel wall defines the reduced outer diameter of the expandable structure, thereby reducing the wall thickness of the expandable structure.

[0029] Another example can be seen in medical stents. The medical stent includes: a tubular substrate extending from a proximal end to a distal end, the tubular substrate being movable between a contractile configuration and an expandable configuration; and a compliance layer extending over at least a portion of the tubular substrate, the compliance layer having a relaxed thickness when unconstrained, and the compliance layer being adapted to compress to a reduced thickness when constrained.

[0030] Alternatively or additionally, the compliant layer defines a plurality of voids. When the compliant layer maintains its relaxed configuration, the voids have a first average size, and when the compliant layer is compressed to the reduced thickness, the voids have a second average size smaller than the first average size.

[0031] Alternatively or additionally, the tubular substrate may include an inner layer, and the compliant layer may include an outer layer movable relative to the inner layer. When the compliant layer maintains its relaxed thickness, the outer layer may be spaced apart from the inner layer by a first distance, and when the compliant layer is compressed to a reduced thickness, the outer layer may be spaced apart from the inner layer by a second distance. The second thickness is less than the first thickness.

[0032] Alternatively or additionally, the compliance layer may include a plurality of rings, at least some of which have a relaxed configuration in which the rings extend radially outward relative to the longitudinal axis of the medical stent.

[0033] Alternatively or additionally, the ring extending radially outward relative to the longitudinal axis of the medical stent may be adapted to fold when compressed due to contact with the vessel wall, thereby reducing the wall thickness of the expandable structure.

[0034] Alternatively or additionally, a ring having the relaxation configuration may define the relaxation thickness of the compliant layer, in which the ring extends radially outward.

[0035] Alternatively or additionally, when the ring is folded, the ring adapted to be compressed and folded can define the reduced thickness of the compliant layer.

[0036] Another example can be seen in medical stents adapted for deployment within a blood vessel having lateral branches extending from the vessel, the stent being adapted to be deployed within the blood vessel at a location crossing the lateral branches. The medical stent includes: a substrate extending from a proximal end to a distal end, the substrate defining a tubular body movable between a contractile configuration and a dilatational configuration; and a compliance layer extending over at least a portion of the substrate, the compliance layer being adapted to contact and be compressed against the vessel wall of the blood vessel. A portion of the compliance layer corresponding to the location where the lateral branch extends from the vessel remains uncompressed.

[0037] Alternatively or additionally, the compressed portion of the compliant layer may have a smaller void size than the uncompressed portion of the compliant layer.

[0038] Alternatively or additionally, the compression portion of the compliance layer can hold the plaque in the proper position between the compliance layer and the vessel wall.

[0039] Alternatively or additionally, the uncompressed portion of the compliance layer can allow blood flow through the compliance layer between the vessel and its lateral branches.

[0040] The foregoing description is provided to facilitate understanding of some of the innovative features unique to this disclosure and is not intended to be a complete description. A full understanding of this disclosure can be obtained by considering the entire specification, claims, drawings, and abstract as a whole. Attached Figure Description

[0041] This disclosure can be more fully understood in light of the following description of various examples taken in conjunction with the accompanying drawings, in which:

[0042] Figure 1 It is a partial cross-sectional view of a part of the human head and neck, depicting some of the vascular systems inside the neck.

[0043] Figure 2 This is a schematic diagram of an example of a medical stent that includes an inner tubular component and an outer tubular component.

[0044] Figure 3 This is a schematic diagram of an example of a sexual medical stent deployed inside a bifurcation or branch blood vessel.

[0045] Figure 4 It is along Figure 3 The cross-sectional view taken from line 4-4.

[0046] Figure 5 It is along Figure 3 The cross-sectional view taken from line 5-5.

[0047] Figure 6A , Figure 6B and Figure 6C This is a schematic diagram of a portion of an exemplary bracket.

[0048] Figure 7A and Figure 7B This is a schematic diagram of a portion of an exemplary bracket.

[0049] Figure 8 This is a schematic diagram of a portion of an exemplary bracket.

[0050] Figure 9A and Figure 9B This is a schematic diagram of a portion of an exemplary bracket.

[0051] Figure 10 This is a schematic diagram of a portion of an exemplary support, showing an open-loop knit pattern.

[0052] Figure 11 This is a schematic diagram of a portion of an exemplary support, showing a twisted loop knit pattern.

[0053] Figure 12A and Figure 12B This is a schematic diagram of a portion of an exemplary bracket.

[0054] While the implementation is readily adaptable to various modifications and alternatives, its details have been illustrated by way of example in the accompanying drawings and will be described in detail. Nevertheless, it should be understood that this disclosure is not intended to be limited to the specific examples described. Rather, it is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure. Detailed Implementation

[0055] The following description should be read with reference to the accompanying drawings, in which similar elements in different drawings are numbered in a similar manner. The drawings (which are not necessarily to scale) depict examples, and these examples are not intended to limit the scope of this disclosure. Although examples of various elements are depicted, those skilled in the art will recognize that many of the examples provided have suitable alternatives that can be utilized.

[0056] Unless otherwise expressly stated otherwise, all figures in this document are modified by the term “about”. Numerical ranges listed by endpoints include all values ​​contained within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0057] As used in this specification and the appended claims, the singular forms “a” and “the”, and where no quantifier is used, include plural indicators, unless otherwise expressly stated. As used in this specification and the appended claims, the term “or” is generally used in the sense that it includes “and / or”, unless otherwise expressly stated.

[0058] Note that references to "one embodiment," "some embodiments," "other embodiments," etc., in the specification indicate that the described embodiments may include specific features, structures, and characteristics, but not every embodiment necessarily includes that specific feature, structure, and / or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an embodiment, it can be understood that, unless explicitly stated otherwise, that feature, structure, or characteristic may be applied to other embodiments, whether or not it is explicitly described.

[0059] Figure 1 It is a partial sectional view of the human head and neck, showing some of the vascular systems. Figure 1 The common carotid artery 10 is shown, bifurcating into the external carotid artery 12 and the internal carotid artery 14. This is just one of many examples of bifurcated or collateral vessels. Lesion 16 is schematically shown inside the internal carotid artery 14, just above the bifurcation point 18. An arterial sheath can be advanced through the vascular system to the point inside the common carotid artery 10, and an expandable occlusion balloon carried by the arterial sheath can be used to occlude the antegrade blood flow through the common carotid artery 10. The common carotid artery 10 can be reached by advancing through the arterial system. Access to the arterial system can be made via many different arteries, but in some cases, access can be made via one of the patient's femoral arteries, as the patient has a femoral artery that extends through the groin and down each leg. In some cases, other arteries providing a shorter path to the common carotid artery 10 can be utilized. Once access to the common carotid artery, a variety of different procedures can be performed.

[0060] In some cases, a stent may be deployed within the common carotid artery 10, and, as an example, in some cases, a stent may cover the external carotid artery 14. Placing a stent in this location can cause displacement of plaque located on the vessel wall of the common carotid artery 10. It is desirable to minimize plaque displacement, particularly in this region, as displaced plaque may travel into the brain, especially if the plaque reaches the internal carotid artery 12. Furthermore, there are multiple vascular connections between the internal carotid artery 12 and the external carotid artery 14 within the head. When a stent covers the external carotid artery 14, the stent itself can restrict blood flow from the common carotid artery 10 to the external carotid artery 14. In some cases, it is desirable to allow this blood flow without substantially affecting it.

[0061] Figure 2 This is a schematic diagram illustrating an exemplary medical stent 20. Figure 2 In this illustration, while the exemplary medical stent 20 is shown as generally tubular, it is conceivable that the medical stent 20 may take any desired cross-sectional shape. The medical stent 20 may be considered to include a proximal region 22, a distal region 24, and an intermediate region 26; it should be recognized that these designations are arbitrary and depend on the orientation of the medical stent 20 to be ultimately implanted within a body cavity. The medical stent 20 may be considered to have a constant diameter over its entire length (including the proximal region 22, distal region 24, and intermediate region 26), particularly when unconstrained. When the medical stent 20 is deployed within a blood vessel, it should be understood that the blood vessel may influence the profile of the medical stent 20, as it may cause portions of the medical stent 20 to be compressed or otherwise deformed. In some cases, when in a relaxed equilibrium state, the medical stent 20 may be considered to have a constant diameter. The medical stent 20 may include a lumen 28 extending from the proximal end 30 of the medical stent 20 to the distal end 32 of the medical stent 20 to allow blood to pass through it. The medical stent 20 may be considered to have a longitudinal axis LA. The medical stent 20 can expand from a first radially contracting configuration (not shown) to a second radially expanding configuration, which can correspond to its relaxed equilibrium state. In some cases, the medical stent 20 can be configured to extend through a stenosis and apply radially outward pressure to the stenosis in the lumen in order to open the lumen and allow blood to pass through it.

[0062] The medical stent 20 includes an expandable tubular structure 34 extending from a proximal end 30 to a distal end 32. In some cases, the expandable tubular structure 34 may comprise a single layer or a structure. In some cases, the expandable tubular structure 34 may include a tubular substrate 36 and a compliant layer 38 disposed above the tubular substrate 36. In some cases, the expandable tubular structure 34 may be movable between a radially contracting configuration (not shown) and a radially expanding configuration (as shown). The tubular substrate 36 may take various forms. In some cases, the tubular substrate 36 may be a stent formed from a plurality of interconnected struts, which are formed into a single structure by tubular members. For example, the tubular substrate 36 may be a laser-cut stent, which is a stent laser-cut from a cylinder (e.g., a metal tube). The EPIC™ stent manufactured by Boston Scientific, Corporation is an example of a laser-cut stent. In other cases, the tubular substrate 36 may be a tubular structure formed from one or more interlaced threads. In some cases, the tubular substrate 36 may be a braided stent, for example, formed from multiple braided threads. Some exemplary scaffolds that include braided filaments include the WallFlex®, WALLSTENT®, and Polyflex® scaffolds manufactured and distributed by Boston Scientific, Corporation. In some cases, the tubular substrate 36 may be adapted to provide an additional surface, for example, for a washable drug coating. In some cases, the tubular substrate 36 may be a braided tubular member (such as a knitted scaffold), which is a scaffold formed by weaving one or more filaments together. In some cases, the knitted scaffold may include an open-loop knit pattern. In some cases, the knitted scaffold may include a twisted-loop knit pattern. The EPIC™ scaffold manufactured by Boston Scientific, Corporation is an example of a knitted scaffold. In some cases, the tubular substrate 36 may be of the knotted type, such as the Precision Colonic™ scaffold manufactured by Boston Scientific, Corporation.

[0063] The compliant layer 38 circumferentially surrounding the tubular substrate 36 can be adapted to have a default or relaxed (e.g., balanced) configuration, in which the compliant layer 38 maintains a relaxed outer diameter (in Figure 2 The diameter is indicated as D1. In some cases, portions of the compliance layer 38 may be adapted to be radially constrained in response to contact between portions of the compliance layer 38 and the vessel wall, or in response to contact between portions of the compliance layer 38 and obstructions within the vessel (such as...). Figure 1As shown in lesion 16), compression or otherwise reduction in outer diameter occurs. In some cases, when the compliance layer 38 is in its relaxed configuration, the compliance layer 38 may define a first pore or void size in its relaxed diameter D1, and when the compliance layer 38 or a portion thereof is radially compressed due to radial constraint, the compliance layer 38 or a portion thereof may define a second pore or void size. The second pore or void size may be smaller than the first pore or void size. As a result, the portion of the compliance layer 38 compressed due to constraint has a smaller pore or void size and can therefore better capture plaques and other debris that might otherwise be released due to the deployment of the medical stent 20. Furthermore, the portion of the compliance layer 38 retained in a relaxed configuration (such as where the medical stent 20 crosses a lateral vessel and no radially inward force is applied to the compliance layer 38) has a relatively large pore or void size and can therefore allow blood to flow through the sidewalls of the stent 20 between the vessel and its lateral vessel. The medical stent 20 can be considered an uncovered stent having a channel extending from the outside of the medical stent 20 through the tubular wall of the medical stent 20 into the lumen of the medical stent 20. The channel may be defined by the interconnecting void spaces of the compliant layer 38 and the void spaces of the tubular substrate 36.

[0064] In some cases, the compliant layer 38 can be formed from any of a variety of different materials. Depending on the material and construction of the compliant layer 38, consider cases where the medical stent 20 may include only the compliant layer 38 and may not include the tubular substrate 36. As an example, in some cases, as will be discussed, the compliant layer 38 may include a knitted pattern having a plurality of loops woven from filaments. At least some of the loops may extend radially outward from the longitudinal axis LA and thus may define a relaxed construction (defining a diameter D1), while other loops may define the necessary structure to support the compliant layer 38. For example, in some cases, the compliant layer 38 may include filaments wound into loose coils.

[0065] In some cases, the medical stent 20 may be a self-expanding stent (SES), meaning that the medical stent 20 will automatically expand into its expanded configuration once any constraints preventing expansion are removed. In other cases, the medical stent 20 may not be a self-expanding stent and may therefore rely on an expandable balloon or other expandable member within the lumen 28 to allow the medical stent 20 to expand from its contractile configuration for delivery to its expanded configuration for deployment.

[0066] The tubular support 36 and the compliance layer 38 can be formed of any suitable material. For example, the tubular support 36 and the compliance layer 38 can each be independently formed of metal, metal alloy, shape memory alloy, or polymer as needed, allowing the medical stent 20 to expand into a shape when accurately positioned in the body. In some cases, materials can be selected to allow the medical stent 20 to be removed relatively easily. For example, each of the tubular support 36 and the compliance layer 38 can be formed of an alloy, such as, but not limited to, nitinol and Elgiloy®. In some cases, one or more of the tubular support 36 and the compliance layer 38 can be formed from one or more nitinol filaments. In some cases, the tubular support 36 can be laser-cut from a nitinol cylinder or tube. In some cases, the combination of the tubular support 36 and the compliance layer 38 can enhance the transfer of any elutable drug disposed on at least one of the tubular support 36 and the compliance layer 38.

[0067] Figure 3 This is a schematic diagram showing a medical stent 20 disposed within a blood vessel 40, which has side branches 42 branching off from it. The blood vessel 40 includes a vessel wall 44. The medical stent 20 is sized to fit within the blood vessel 40 such that when the medical stent 20 expands radially to its radially expanded configuration, the compliance layer 38 is at least partially radially compressed due to constraint by the vessel wall 44. It can be seen that the compliance layer 38 is at least partially radially compressed wherever it contacts the vessel wall 44, and is not radially compressed where it extends through the side branches 42, and is therefore not constrained by contact with the vessel wall 44. Figure 4 This is a cross-sectional view taken along line 4-4. Figure 5 This is a cross-sectional view taken along line 5-5. For example... Figure 4 As shown, the portion of the compliance layer 38 constrained by the vessel wall 44 is compressed to a reduced diameter, resulting in a reduction in the size of the pores or voids within the compliance layer 38. The portion 38a of the compliance layer 38 covering the lateral branch 42 is not compressed but remains at its relaxed diameter. Figure 5 As shown, the entire circumference of the compliance layer 38 is constrained by the vessel wall 44, and thus compressed to a reduced diameter. In other words, when unconstrained, a portion of the compliance layer 38 may have a first radial thickness or a relaxed radial thickness (measured from the radially inner extent to the radially outer extent of the compliance layer 38), and when radially constrained, may have a second thickness or a reduced thickness less than the first or relaxed thickness. Therefore, as Figure 4 As shown, the portion of the compliant layer 38 that does not contact the vessel wall 44 and is therefore not constrained by contact with the vessel wall 44 can have a greater radial thickness than the portion of the compliant layer 38 that contacts and is constrained by the vessel wall 44.

[0068] Figures 6A to 6CThis is a schematic diagram of a portion of an exemplary stent 50. The exemplary stent 50 can be considered as an example of a medical stent 20. The stent 50 includes an outer layer 52 and an inner layer 54. In some cases, the outer layer 52 can be considered as a compliant layer, and the inner layer 54 can be considered as part of a tubular support. The outer layer 52 is connected to the inner layer 54 via a plurality of struts 56 extending between a transverse member 58 forming part of the outer layer 52 and a transverse member 60 forming part of the inner layer 54. The outer layer 52 can be considered to include additional transverse members 62 extending transversely to and intersecting above and / or below the transverse members 58. The inner layer 54 can be considered to include additional transverse members 64 extending transversely to and intersecting above and / or below the transverse members 60. Transverse members 56 and 62 can each be considered to be in a plane defined by the outer layer 52, and transverse members 58 and 64 can each be considered to be in a plane defined by the inner layer 54. Transverse members 58 and 60 can be considered to extend into and above the plane of the drawing. In some cases, transverse members 58 and 62 may be formed as a braided structure, wherein transverse member 62 is interwoven with transverse member 58 to form outer layer 52. Similarly, in some cases, transverse members 60 and 64 may be formed as a braided structure, wherein transverse member 60 is interwoven with transverse member 64 to form inner layer 54. The medical stent 50 can be considered an uncovered stent having multiple channels extending from the outside of the medical stent 50 through the tubular wall of the medical stent 50 into the lumen of the medical stent 50. The multiple channels may be defined by void spaces extending through the wall of the medical stent 50.

[0069] like Figure 6A As shown, the outer layer 52 is in a relaxed configuration relative to the inner layer 54, defining a first distance between the outer layer 52 and the inner layer 54. This can be considered as defining the size of a first hole or void within the support 50. Figure 6B As shown, the outer layer 52 has moved closer to the inner layer 54, and has actually been axially displaced in the process, thereby reducing the radial distance between the outer layer 52 and the inner layer 54, and thus reducing the radial thickness of the support 50. Although in Figure 6A The strut 56 is seen to be orthogonal or at least substantially orthogonal to the outer layer 52 and the inner layer 54 (defined as within 10% of orthogonality), but the strut 56 is now parallel or at least substantially parallel to the outer layer 52 and the inner layer 54 (defined as within 10% of parallelism). This corresponds to the outer layer 52 being pushed closer to the inner layer 54 due to the constraint of contact with the vessel wall, thereby reducing the radial distance between the outer layer 52 and the inner layer 54, and thus reducing the radial thickness of the stent 50.

[0070] Figure 6CA schematic example is provided showing how the gap formed between the outer layer 52 and the inner layer 54, and the support column 56, can vary depending on the relative radial positions of the outer layer 52 and the inner layer 54. It can be seen that the outer layer 52 includes a plurality of orthogonal transverse members 58 and 62, and the inner layer 54 includes a plurality of orthogonal transverse members 60 and 64. When the outer layer 52 and the inner layer 54 are as follows... Figure 6A When positioned as shown, transverse members 60 and 64 are aligned with transverse members 58 and 62, and the gap size corresponds to a square defined by the distance between adjacent transverse members 58 and 62 (in the outer layer 52) or the distance between adjacent transverse members 60 and 64 (in the inner layer 54). When the outer layer 52 and the inner layer 54 are as shown... Figure 6B (and Figure 6C As shown in the diagram, when the outer layer 52 has been laterally (and radially) shifted relative to the inner layer 54, the lateral members 60 and 64 are not aligned with the lateral members 58 and 62. Instead, the lateral members 60 and 64 are positioned between the lateral members 58 and 62, such that the lateral members 58 and 62 of the outer layer 52 traverse or extend through the gaps (e.g., open cells) of the inner layer 54, effectively dividing the gaps (e.g., open cells) defined by the lateral members 60 and 64. Figure 6C As shown, the result is that the size of the gap defined by the wall through the support 50 is approximately as follows: Figure 6A The void size shown is 25%. In other cases, the outer layer 52 and the inner layer 54 are constructed such that: radially constraining the outer layer 52 toward the inner layer 54 can reduce the effective void size defined by the wall through the support 50 by, for example, two times or more, three times or more, four times or more, or five times or more.

[0071] Figure 7A and Figure 7B This is a schematic diagram of a portion of an exemplary stent 70. The exemplary stent 70 includes a plurality of struts 72. In some cases, the struts 72 may be part of an integral tubular structure (such as a laser-cut tubular structure). In some cases, the struts 72 may be part of a woven tubular structure. A plurality of planar loops 74 are formed by weaving a plurality of filaments 76 between the struts 72. The loops 74 may be formed in any of a variety of ways, including open loop knitted patterns or twisted loop knitted patterns. The medical stent 70 can be considered an uncovered stent having channels extending from the exterior of the medical stent 70 through the tubular walls of the medical stent 70 into the lumen of the medical stent 70. These channels may be defined by gaps or voids between the individual loops (rings) 74. Figure 7A In this configuration, ring 74 can be considered to extend upwards into a plane extending through multiple struts 72. This corresponds to a relaxation configuration, where struts 72 and ring 74 together define relatively large gaps that more easily allow blood flow. Figure 7BIn the middle, ring 74 can be considered relative to them in Figure 7A The position is bent or folded, thereby reducing the radial thickness of the support 70. Figure 7B In this configuration, when ring 74 is radially constrained and thus moves closer to support 72, ring 74 does not protrude as high from the plane passing through support 72 as before. As a result, support 72 and ring 74 define a relatively small gap through the wall of support 70, which better captures the plaque.

[0072] Figure 8 This is a schematic diagram of a portion of an exemplary stent 80. The exemplary stent 80 includes a plurality of woven loops 82 fixed relative to a substrate 84. For example, the substrate 84 may represent a portion of the stent. The textile loops 82 may be formed in any of a variety of ways, including open-loop knitted patterns or twisted-loop knitted patterns. The medical stent 80 can be considered an uncovered stent having a channel extending from the exterior of the medical stent 80 through the tubular wall of the medical stent 80 into the lumen of the medical stent 80. The channel may be defined by gaps or voids between the loops 82. Figure 8 At the top, the woven loop 82 extends above the substrate 84 and can be considered as extending radially outward from the substrate 84, thus providing radial thickness to the stent 80. This corresponds to a relaxation configuration, where the woven loop 82 defines relatively large gaps that more easily allow blood to flow through the walls of the stent 80. Figure 8 At the bottom, due to the constraint of contact with the vessel wall, the braided loop 82 has been compressed downward toward the substrate 84. The braided loop 82 can be considered bent or folded and does not extend as far in the radial direction relative to the substrate 84, thereby reducing the radial thickness of the stent wall 80. As a result, the braided loop 82 defines a relatively small gap through the wall of the stent 80, which better captures plaque.

[0073] Figure 9A and Figure 9B This is a schematic diagram of a portion of an exemplary bracket 90. Figure 9A It is a top view, and Figure 9BThis is a side view. An exemplary support 90 includes a plurality of support pillars 92, as shown, arranged parallel to each other. In some cases, the support pillars 92 may be part of an integral tubular structure (such as a laser-cut support). In some cases, the support pillars 92 may be part of a braided support. A plurality of coils 94 are wound around the support pillars 92, each coil 94 being formed of a filament 96. For example, the filament 96 may be formed of any metal. In some cases, coils 94 are present around each support pillar 92. In some cases, each coil 94 may be wound around two or more adjacent support pillars 92. In some cases, the first support pillar 92 may include coils 94, but adjacent support pillars 92 may not include coils 94. Support pillars 92 may alternate between including and not including coils 94. In some cases, coils 94 may be periodically welded or adhesively attached to the support pillars 92. The medical stent 90 can be considered an uncovered stent having a channel extending from the outside of the medical stent 90 through the tubular wall of the medical stent 90 into the lumen of the medical stent 90. The channel may be defined by the gap or void between the coils 94.

[0074] exist Figure 9B The top view shows a stent 90 in a relaxed configuration, where coils 94 extend radially outward from stent struts 92, thereby providing a relaxed radial wall thickness to the stent 90. The relaxed configuration defines a relatively large void through the wall of the stent 90, which facilitates blood flow. Figure 9B The bottom view shows coil 94 in a radially compressed configuration due to its contact with the vessel wall. As can be seen, coil 94 has collapsed on itself, reducing the radial thickness of the stent wall and thus creating a relatively small gap through the stent wall, which can more easily capture plaque.

[0075] Figure 10 This is a schematic diagram of an exemplary knitted pattern 100, which can be considered an example of an open-loop knitted pattern. The knitted pattern 100 can be used to form some of the compliant layers 38 shown in the previous figures. In some cases, the knitted pattern 100 can be used to form a support including the compliant layer 38. The knitted pattern 100 can be produced using an automated weft knitting process that knits filaments 102 into columns 104 and rows 106 of parallel knit stitches. In some cases, the parallel posts 104 can extend parallel to the longitudinal axis LA of the support in both an expanded relaxed configuration and an elongated constrained configuration. For example, at least some loops within the knitted pattern 100 can be adapted to extend radially outward.

[0076] Figure 11This is a schematic diagram of an exemplary knitted pattern 110, which can be considered an example of a twisted loop knitted pattern. The knitted pattern 110 can be used to form some of the compliant layers 38 shown in the previous figures. In some cases, the knitted pattern 110 can be used to form a support including the compliant layer 38. The knitted pattern 110 is knitted from filaments 112 interwoven with itself, thereby defining openings 114. The filaments 112 can be monofilaments. In some cases, the filaments 112 can be two or more filaments wound, woven, or spun together.

[0077] Knitted pattern 110 may include multiple rows 150a, 150b, 150c, 150d (collectively referred to as 150). Knitted pattern 110 may include any desired number of rows 150. For example, the number of rows 150 may be selected to achieve a desired length. The uppermost or first row 150a may be unfixed and movable. In some cases, the first row 150a may include a plurality of loops 160a, 160b, 160c (collectively referred to as 160). Each loop 160 may each include loop portions 162a, 162b, 162c (collectively referred to as 162) and overlapping base portions 164a, 164b, 164c (collectively referred to as 164). The overlapping base portions 164a, 164b, 164c are understood to be portions of loop 160, wherein a segment of filament overlaps or crosses over a second segment of filament, wherein the filament segments forming the loop portions 162a, 162b, 162c extend therebetween. Adjacent loops 160 can be interconnected via crossbar segments 166a, 166b (collectively referred to as 166). For example, a first crossbar segment 166a can extend between the base portion 164a of a first loop 160a and the second base portion 164b of a second loop 160b. The next row 150b can be suspended over the loops 160 of the first row 150a. For example, the second row 150b can include multiple loops 170a, 170b, 170c (collectively referred to as 170), each loop including loop portions 172a, 172b, 172c (collectively referred to as 172) and base portions 174a, 174b, 174c (collectively referred to as 174). Adjacent loops 170 can be interconnected via crossbar segments 176a, 176b (collectively referred to as 176). When the knitted pattern 110 is knitted, the loop portion 172 can be wrapped around the base portion 164 of the previous row 150a.

[0078] It is conceivable that a single row 150 can be formed at once. For example, rows can be formed continuously, with a subsequent row (e.g., row 150b) formed after a complete rotation of the previous row (e.g., row 150a). Although not explicitly shown, the loop 160 of the first row 150a can be wound around a section of filament 112 without loops. As described herein, the loop 170 of the second row 150b can be wound around the base portion 164 of the loop 160 of the previous row 150a. For example, the filament 112 can be knitted such that it extends from the first cross section 176a, wraps around the base portion 164b of the previous row 150a, crosses itself to form the base section 174b, and continues to the next cross section 176b. It is conceivable that the loop portion 170 can be positioned on a first side of the cross sections 166a, 166b and on a second opposite side of the loop portion 162b. In other words, the filament 112 can be wound such that it extends on top of, behind, and above the base portion 174b of the loop 170b that passes through it to form the second row 150b, and above the first row 166a. An alternative configuration is also conceivable, wherein the filament 112 can be wound such that it extends behind, above, or on top of the base portion 174b of the loop 170b that passes through it to form the second row 150b, and above the first row 166a. For example, at least some loops within the knitted pattern 110 can be adapted to extend radially outward.

[0079] Figure 12A and Figure 12B This is a schematic diagram of a portion of an exemplary stent 180. The exemplary stent 180 may include a plurality of struts 182 forming a tubular substrate, although only one strut 182 is shown. In some cases, the strut 182 may be part of an integral tubular structure (such as a laser-cut tubular structure). In some cases, the strut 182 may be part of a braided structure. A plurality of strands 184 are attached to the struts 182 and extend radially outward from the struts 182. In some cases, the strands 184 may be adhesively attached to the struts 182. Other attachment methods, such as welding or brazing, may also be used. The medical stent 180 can be considered an uncovered stent having a channel extending from the outside of the medical stent 180 through the tubular wall of the medical stent 180 into the lumen of the medical stent 180. The channel may be defined by an interconnecting gap space or void between the strands 184 and the struts 182. Figure 12A As shown, the strands 184 extending radially outward from the strut 182 can be considered a relaxed structure, wherein the strut 182 and the strands 184 together define the radial wall thickness of the stent 180, which has relatively large gaps that allow blood flow more easily through the wall of the stent 180. Figure 12BIn the middle, the stock line 184 has already been relative to them in Figure 12A The position is bent or folded, thereby reducing the radial wall thickness of the support 180. Figure 12B In this configuration, the strand 184 does not extend as far above the support 182, thus the support 182 and the strand 184 define a relatively small gap through the wall of the support 180, which better captures the plaque.

[0080] Materials that can be used for the various components and elements of the medical stents disclosed herein may include materials commonly associated with medical devices. For simplicity, the following discussion refers to devices. However, this is not intended to limit the devices and methods described herein, as such discussion can be applied to other elements, components, assemblies, or devices disclosed herein, such as, but not limited to, medical stents and / or their components or assemblies. In some cases, devices and / or their components may be made of metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, or other suitable materials.

[0081] Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block esters, polyurethanes (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester copolymers (e.g., butene / poly(alkylene ether) phthalates and / or other polyester elastomers, e.g., HYTREL® available from DuPont), polyamides (e.g., DURETHAN® available from Bayer or available from Elf...). Atochem's CRISTAMID®, elastic polyamides, block polyamides / ethers, polyether block amides (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), MARLEX® high-density polyethylene, MARLEX® low-density polyethylene, linear low-density polyethylene (e.g., REXELL®), polyesters, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), trimethyl terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyether imide (PEI), polyphenylene sulfide (PPS), polyethylene oxide (PPO), polyterephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (e.g., available from EMS American) Grilon obtains GRILAMID®, perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, polyurethane-silicone copolymers (e.g., ElastEon® from Aortech Biomaterials or ChronoSil® from AdvanSource Biomaterials), ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, etc. In some embodiments, the sheath may be blended with a liquid crystal polymer (LCP). For example, the blend may contain up to about 6% LCP.

[0082] Some examples of suitable metals and metal alloys include stainless steels such as 304V, 304L, and 316LV stainless steels; low-carbon steels; nickel-titanium alloys such as linearly elastic and / or hyperelastic nickel-titanium; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as INCONEL® 625; UNS: N06022, such as HASTELLOY® C-22®; UNS: N10276, such as HASTELLOY® C276®, other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as MP35-N®, etc.), and nickel-molybdenum alloys (e.g., UNS: 10665, such as HASTELLOY® ALLOY). B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as ELGILOY®, PHYNOX®, etc.); platinum-rich stainless steel; titanium; platinum; palladium; gold; combinations thereof; or any other suitable material.

[0083] In at least some cases, parts or all of the device and / or its components may be doped with, made of, or otherwise include radiopaque materials. Radiopaque materials should be understood as materials capable of producing a relatively bright image on a fluorescent screen or other imaging technique during medical procedures. This relatively bright image helps the user of the device determine its location. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, etc. Additionally, other radiopaque marking strips and / or coils may be incorporated into the design of the device to achieve the same result.

[0084] In some cases, a degree of magnetic resonance imaging (MRI) compatibility is imposed on the devices and / or other components disclosed herein. For example, the devices and / or their components or portions may be made of materials that substantially do not distort the image and do not produce significant artifacts (e.g., gaps in the image). For example, certain ferromagnetic materials may be unsuitable because they can produce artifacts in MRI images. The devices or portions thereof may also be made of materials that an MRI machine can image. Some materials exhibiting these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as ELGILOY®, PHYNOX®, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as MP35-N®, etc.), nitinol, and others.

[0085] In some cases, the devices and / or other elements disclosed herein may include and / or be treated with suitable therapeutic agents. Examples of suitable therapeutic agents may include antithrombotic agents (such as heparin, heparin derivatives, urokinase, and PPack (d-phenylalanine-proline-arginine-chloromethyl ketone)); antiproliferative agents (e.g., enoxaparin, angiopeptidase, monoclonal antibodies capable of blocking smooth muscle cell proliferation, hirudin, and acetylsalicylic acid); anti-inflammatory agents (e.g., dexamethasone, prednisolone, corticosteroids, budesonide, estrogens, sulfasalazine, and mesalazine); antitumor / antiproliferative / antimitotic agents (e.g., paclitaxel, 5-fluorouracil, cisplatin, vincristine, epoch-forming acid, endostatin, angiostatin, and thymidine kinase inhibitors); anesthetics (e.g., lidocaine, bupivacaine, and ropivacaine); and anticoagulants (e.g., D-Phe-Pro- Arg chloromethyl ketone, compounds containing RGD peptides, heparin, antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, antiplatelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and tick antiplatelet peptides; angiogenesis promoters (e.g., growth factor inhibitors, growth factor receptor antagonists, transcription activators, and translation initiators); angiogenesis inhibitors (e.g., growth factor inhibitors, growth factor receptor antagonists, transcription repressors, translation repressors, replication inhibitors, inhibitory antibodies, antibodies against growth factors, bifunctional molecules composed of growth factors and cytotoxins, bifunctional molecules composed of antibodies and cytotoxins); cholesterol lowering agents; vasodilators; and agents that interfere with endogenous vasoactivity mechanisms.

[0086] Therefore, several illustrative examples of this disclosure have been described, and those skilled in the art will readily understand that other examples may be made and used within the scope of the appended claims. However, it will be understood that this disclosure is merely illustrative in many respects. Changes in detail may be made without departing from the scope of this disclosure, particularly in terms of shape, size, arrangement of components, and exclusion and order of steps. The scope provided by the disclosure is, of course, defined by the language of the appended claims.

Claims

1. A medical stent, comprising: An expandable structure capable of moving between a contractile structure for delivery and an expandable structure for deployment, wherein the expandable structure in the expandable structure defines a relaxed outer diameter; in: The expandable structure retains its relaxed outer diameter in portions that are constrained and not in contact with the blood vessel wall after deployment; and After deployment, some portions of the expandable structure that were compressed due to contact with the blood vessel wall are moved to a reduced outer diameter that is smaller than the relaxed outer diameter.

2. The medical stent of claim 1, wherein the expandable structure defines a plurality of voids through the wall of the expandable structure, and wherein: When the expandable structure maintains its relaxed configuration, the void has a first average size; and When the expandable structure is compressed to the reduced outer diameter, the void has a second average size that is smaller than the first average size.

3. The medical stent of claim 1 or 2, wherein the expandable structure comprises an inner layer and an outer layer movable relative to the inner layer, and wherein: When the expandable structure maintains its relaxed outer diameter, the outer layer and the inner layer are spaced apart by a first distance; and When the expandable structure is compressed to reduce its outer diameter, the outer layer and the inner layer are spaced apart by a second distance. The second distance is less than the first distance.

4. The medical stent of claim 1 or 2, wherein the expandable structure comprises a knitted stent.

5. The medical stent of claim 4, wherein the knitted stent comprises a plurality of loops, at least some of the loops having a relaxed configuration in which the loops extend radially outward relative to the longitudinal axis of the medical stent.

6. The medical stent of claim 5, wherein the ring extending radially outward relative to the longitudinal axis of the medical stent is adapted to fold upon compression due to contact with the vessel wall.

7. The medical stent of claim 5, wherein the ring having a relaxation configuration defines the relaxation outer diameter of the expandable structure, wherein the ring extends radially outward in the relaxation configuration.

8. The medical stent of claim 6, wherein the ring adapted to fold when compressed defines the reduced outer diameter of the expandable structure when folded.

9. The medical stent of any one of claims 1 to 3, wherein the expandable structure comprises: One or more slender pillars; as well as One or more filaments are wound around each of the one or more elongated pillars; in: The one or more filaments form a coil with a relaxed structure, the relaxed structure defining the relaxed outer diameter of the expandable structure; and Some portions of the coil, compressed due to contact with the blood vessel wall, define the reduced outer diameter of the expandable structure.

10. A medical stent, comprising: A tubular substrate extending from a proximal end to a distal end, the tubular substrate being movable between a radially contracting configuration and a radially expanding configuration; as well as A compliant layer extending over at least a portion of the tubular substrate, the compliant layer having a relaxed thickness when not radially constrained, and the compliant layer being adapted to be radially compressed to reduce its thickness when radially constrained.

11. The medical stent of claim 10, wherein the compliance layer comprises a plurality of rings, at least some of the rings having a relaxation configuration in which the rings extend radially outward relative to the longitudinal axis of the medical stent.

12. The medical stent of claim 11, wherein the ring extending radially outward relative to the longitudinal axis of the medical stent is adapted to fold upon radial compression due to contact with the vessel wall.

13. The medical stent of claim 11, wherein the ring having the relaxation configuration defines the relaxation thickness of the compliance layer, the ring extending radially outward in the relaxation configuration.

14. The medical stent of claim 13, wherein the ring adapted to fold when compressed defines the reduced thickness of the compliant layer when folded.

15. A medical stent adapted for deployment within a blood vessel having lateral branches extending therefrom, the medical stent being adapted to be deployed within the blood vessel at a location crossing the lateral branches, the medical stent comprising: A substrate extending from a proximal end to a distal end, the substrate defining a tubular body movable between a radially contracting configuration and a radially expanding configuration; as well as A compliant layer extending over at least a portion of the substrate, the compliant layer being adapted to be radially compressed due to contact with the vessel wall of the blood vessel; The combination of the substrate and the compliant layer defines the wall of the medical stent; The first portion of the compliance layer is configured to be radially compressed upon contact with the vessel wall when deployed inside the blood vessel; and The second portion of the compliance layer, corresponding to the location of the lateral branch extension, is configured to be less radially compressed or less compressed than the first portion when deployed inside the blood vessel.

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