Stent with dynamic anti-migration characteristics

Abstract

A medical stent includes a central stent section, a proximal stent section adapted to be positioned on a proximal region of the central stent section, and a distal stent section adapted to be positioned on a distal region of the central stent section. A polymeric coating extends over at least a portion of the proximal stent section, the distal stent section, and the central stent section, the polymeric coating being adapted to allow the proximal stent section to float over a proximal region of the central stent section and to allow the distal stent section to float over a distal region of the central stent section. After implantation, the central stent section is adapted to translate relative to the proximal and distal stent sections in response to a peristaltic force.

Description

Cross-references to related applications

[0001] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 514,015, filed July 17, 2023, the disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to methods and apparatus for various digestive system diseases. More specifically, this disclosure relates to different constructions, manufacturing methods, and methods of 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 the patency of those structures. These devices are manufactured using any of a variety of different methods and can be used according to any of those methods. Each of the known medical devices, delivery systems, and methods has its own advantages and disadvantages. There is a need for a continuous supply of alternative medical devices and delivery devices, as well as alternative methods for manufacturing and using these devices and delivery devices. Summary of the Invention

[0004] This disclosure relates to several alternative designs, materials, manufacturing methods, and methods of using medical device structures and components. One example is a medical stent. The medical stent includes: a central stent segment comprising a proximal region and a distal region; a proximal stent segment adapted to be positioned on the proximal region of the central stent segment; and a distal stent segment adapted to be positioned on the distal region of the central stent segment. A polymer coating extends on at least a portion of the central stent segment, the proximal stent segment, and the distal stent segment, the polymer coating being adapted to allow the proximal stent segment to float on the proximal region of the central stent segment and to allow the distal stent segment to float on the distal region of the central stent segment. After implantation, the proximal stent segment and / or the distal stent segment are adapted to translate relative to the central stent segment in response to peristaltic forces.

[0005] Alternatively or additionally, the polymer coating can connect the proximal and distal stent segments to the central stent segment and limit how far the proximal and / or distal stent segments can move relative to the central stent segment.

[0006] Alternatively or additionally, the polymer coating may extend from the proximal end of the central stent segment to the distal end of the central stent segment.

[0007] Alternatively or additionally, the proximal stent segment may have an inner diameter greater than the sum of the outer diameter of the central stent segment and twice the thickness of the polymer coating, and the distal stent segment may have an inner diameter greater than the sum of the outer diameter of the central stent segment and twice the thickness of the polymer coating.

[0008] Alternatively or additionally, the polymer coating may extend onto the proximal stent segment, the central portion of the central stent segment, and the distal stent segment.

[0009] Alternatively or additionally, at least a portion of the proximal region of the central stent segment may be left uncoated to facilitate drainage.

[0010] Alternatively or additionally, the proximal stent segment may have an inner diameter greater than the outer diameter of the central stent segment, and the distal stent segment may have an inner diameter greater than the outer diameter of the central stent segment.

[0011] Alternatively or additionally, the polymer stent segment may include an annular flange.

[0012] Alternatively or additionally, the distal stent segment may include one or more annular flanges.

[0013] Alternatively or additionally, the central stent segment may include a braided stent segment, the proximal stent segment may include a braided stent segment, and the distal stent segment may include a braided stent segment.

[0014] Another example can be found in a method of forming a medical stent, the medical stent including a central stent segment, a proximal stent segment adapted for positioning on a proximal region of the central stent segment, and a distal stent segment adapted for positioning on a distal region of the central stent segment. The method includes: positioning the proximal stent segment, the central stent segment, and the distal stent segment on a mandrel, wherein the proximal stent segment is spaced proximally from the proximal end of the central stent segment by a proximal distance, and the distal stent segment is spaced distally from the distal end of the central stent segment by a distal distance; forming a polymer coating extending from the proximal stent segment to the distal stent segment, the polymer coating spanning between the proximal ends of the proximal stent segment and the central stent segment, and between the distal ends of the central stent segment and the distal stent segment, to form a stent assembly; removing the stent assembly from the mandrel; sliding the proximal stent segment on a proximal region of the central stent segment, and sliding the distal stent segment on a distal region of the central stent segment, to form a medical stent.

[0015] Alternatively or otherwise, the proximal and distal distances may each be within the range of 10% to 50% of the length of the central stent segment.

[0016] Alternatively or additionally, forming a polymer coating may include forming a silicone coating.

[0017] Alternatively or additionally, at least one of the proximal stent segment and the distal stent segment may include an annular flange extending radially outward from the proximal stent segment and / or the distal stent segment.

[0018] Another example can be seen in a medical stent. This medical stent includes a central stent segment and a proximal stent segment. The central stent segment includes a proximal region, a distal flared region, and an intercalary central region. The proximal stent segment is adapted to be positioned on the proximal region of the central stent segment. A polymer coating extends on the proximal stent segment, the distal flared region of the central stent segment, and the intercalary central region. The polymer coating is adapted to self-flip to position the proximal stent segment on the proximal region of the central stent segment.

[0019] Another example can be found in a medical stent. The medical stent includes a central stent segment, a proximal stent segment, and a distal stent segment. The central stent segment includes a proximal region and a distal region. The proximal stent segment is adapted to be positioned on the proximal region of the central stent segment. The distal stent segment is adapted to be positioned on the distal region of the central stent segment. A polymer coating extends on at least a portion of the central stent segment, the proximal stent segment, and the distal stent segment, and is adapted to allow the proximal stent segment to float on the proximal region of the central stent segment and to allow the distal stent segment to float on the distal region of the central stent segment. After implantation, the proximal stent segment and / or the distal stent segment is adapted to translate relative to the central stent segment in response to peristaltic forces.

[0020] Alternatively or additionally, a polymer coating may be used to attach the proximal stent segment to the central stent segment.

[0021] Alternatively or additionally, a polymer coating can connect the distal stent segment to the central stent segment.

[0022] Alternatively or additionally, the polymer coating may limit how far the proximal stent segment and / or distal stent segment can move relative to the central stent segment.

[0023] Alternatively or additionally, the polymer coating may extend from the proximal end of the central stent segment to the distal end of the central stent segment.

[0024] Alternatively or additionally, the proximal stent segment may have an inner diameter greater than the sum of the outer diameter of the central stent segment and twice the thickness of the polymer coating, and the distal stent segment may have an inner diameter greater than the sum of the outer diameter of the central stent segment and twice the thickness of the polymer coating.

[0025] Alternatively or additionally, the polymer coating may extend onto the proximal stent segment, the central portion of the central stent segment, and the distal stent segment.

[0026] Alternatively or additionally, at least a portion of the proximal region of the central stent segment may be left uncoated to facilitate drainage.

[0027] Alternatively or additionally, the proximal stent segment may have an inner diameter greater than the outer diameter of the central stent segment, and the distal stent segment may have an inner diameter greater than the outer diameter of the central stent segment.

[0028] Alternatively or additionally, the polymer stent segment may include an annular flange.

[0029] Alternatively or additionally, the distal stent segment may include one or more annular flanges.

[0030] Alternatively or additionally, the central support segment may include a braided support segment.

[0031] Alternatively or additionally, the proximal stent segment may include a braided stent segment.

[0032] Alternatively or additionally, the distal stent segment may include a braided stent segment.

[0033] Another example can be seen in a method of forming a medical stent, the medical stent including a central stent segment, a proximal stent segment adapted for positioning on a proximal region of the central stent segment, and a distal stent segment adapted for positioning on a distal region of the central stent segment. The method includes: positioning the proximal stent segment, the central stent segment, and the distal stent segment on a mandrel, wherein the proximal stent segment is spaced proximally from the proximal end of the central stent segment, and the distal stent segment is spaced distally from the distal end of the central stent segment. A polymer coating is formed extending from the proximal stent segment to the distal stent segment, the polymer coating spanning between the proximal ends of the proximal stent segment and the central stent segment, and between the distal end of the central stent segment and the distal stent segment, to form a stent assembly. The stent assembly is removed from the mandrel. The proximal stent segment is slid on the proximal region of the central stent segment, and the distal stent segment is slid on the distal region of the central stent segment to form the medical stent.

[0034] Alternatively or otherwise, the proximal distance can be in the range of 10% to 50% of the length of the central stent segment.

[0035] Alternatively or otherwise, the distal distance can be in the range of 10% to 50% of the length of the central stent segment.

[0036] Alternatively or additionally, forming a polymer coating may include forming a silicone coating.

[0037] Alternatively or additionally, at least one of the proximal stent segment and the distal stent segment may include an annular flange extending radially outward from the proximal stent segment and / or the distal stent segment.

[0038] Another example can be seen in a medical stent. This medical stent includes a central stent segment and a proximal stent segment. The central stent segment includes a proximal region, a distal flared region, and an intercalary central region. The proximal stent segment is adapted to be positioned on the proximal region of the central stent segment. A polymer coating extends on the proximal stent segment, the distal flared region of the central stent segment, and the intercalary central region, and is adapted to self-flip to position the proximal stent segment on the proximal region of the central stent segment.

[0039] The above overview is provided to aid in understanding the unique innovative features of this disclosure and is not intended to be a comprehensive description. A full understanding of this disclosure can be obtained by combining the entire specification, claims, drawings, and abstract. Attached Figure Description

[0040] This disclosure can be more fully understood by taking into account the following description of various examples and the accompanying drawings, in which:

[0041] Figure 1 This is a schematic diagram of an exemplary medical stent;

[0042] Figures 2A to 2C It shows the manufacturing process. Figure 1 A schematic diagram of an exemplary manufacturing process for an exemplary medical stent;

[0043] Figures 3A to 3D yes Figure 1 A schematic diagram of an exemplary medical stent implanted in the esophagus;

[0044] Figure 4 This is a schematic diagram of an exemplary medical stent;

[0045] Figure 5 This is a schematic diagram of an exemplary medical stent; and

[0046] Figure 6 This is a schematic diagram of an exemplary medical stent.

[0047] While this disclosure is readily adaptable to various modifications and substitutions, its specific details have been illustrated by way of example in the accompanying drawings and will be described in detail. However, it should be understood that this disclosure is not intended to limit it 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

[0048] The following description should be read in conjunction with the accompanying drawings, in which similar elements in different drawings are numbered in a similar manner. The drawings are not necessarily drawn to scale and depict examples that are not intended to limit the scope of this disclosure. Although examples are illustrated for various elements, those skilled in the art will recognize that many of the examples provided have suitable alternatives available.

[0049] Unless otherwise expressly stated otherwise, all figures herein are considered to be modified by the term “about”. Numerical ranges described 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).

[0050] Unless otherwise expressly specified, the singular forms “a,” “an,” and “the” as used in this specification and the appended claims include plural references. Unless otherwise expressly specified, the term “or” as used in this specification and the appended claims is generally used in its meaning as including “and / or.”

[0051] It should be noted that references to "one embodiment," "some embodiments," "other embodiments," etc., in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but not every embodiment must include that specific feature, structure, or characteristic. Furthermore, these terms do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, it should be understood that such feature, structure, or characteristic can be applied to other embodiments, whether explicitly described or not, unless explicitly stated otherwise.

[0052] Stents are used in a variety of different body cavities, including, for example, the vascular system and various parts of the gastrointestinal system. In some cases, particularly in gastrointestinal applications, the implanted stent may be subjected to a variety of different forces. For example, the gastrointestinal system may perceive the stent as a foreign object to be expelled. In some cases, parts of the gastrointestinal system may attempt to force the implanted stent to move distally. In some cases, parts of the gastrointestinal system may attempt to force the implanted stent to move proximally or upward and outward. It should be understood that parts of the gastrointestinal system naturally undergo movements, such as peristalsis, to move food and food matter (e.g., partially digested food) distally through the gastrointestinal system. Stents placed in various parts of the gastrointestinal system (e.g., but not limited to the esophagus) are subject to peristaltic movements. Figure 1 This is a schematic diagram of an exemplary medical stent 10, which is suitable for use in a body cavity where the medical stent 10 will be subjected to various kinetic forces.

[0053] exist Figure 1 In this embodiment, an exemplary medical stent 10 extends from a proximal side 12 to a distal side 14, recognizing that these designations are arbitrary and depend on the orientation of the medical stent 10 to be ultimately implanted into a body cavity. The medical stent 10 includes a central stent segment 16 having a proximal side region 18 and a distal side region 20. The medical stent 10 includes a proximal stent segment 22 adapted to be positioned on the proximal side region 18 of the central stent segment 16. The medical stent 10 includes a distal stent segment 24 adapted to be positioned on the distal side region 20 of the central stent segment 16. It can be seen that the proximal stent segment 22 and the distal stent segment 24 each have an inner diameter larger than the outer diameter of the central stent segment 16. In some cases, the inner diameters of the proximal stent segment 22 and / or the distal stent segment 24 may be radially outwardly spaced and away from the outer diameter of the central stent segment 16, thereby providing an annular gap between them.

[0054] The central stent segment 16, proximal stent segment 22, and distal stent segment 24 are each separately formed and then assembled into the medical stent 10 as independent components. Therefore, the central stent segment 16 may not be directly connected to the proximal stent segment 22 or the distal stent segment 24. Each of the central stent segment 16, proximal stent segment 22, and distal stent segment 24 can be formed from one or more interwoven filaments. The one or more interwoven filaments of each of the central stent segment 16, proximal stent segment 22, and distal stent segment 24 may not be continuous with the one or more interwoven filaments of other segments. As shown, the central stent segment 16, proximal stent segment 22, and distal stent segment 24 are each formed as a braided stent segment. Various braiding patterns can be used when manufacturing the central stent segment 16, proximal stent segment 22, and distal stent segment 24. In some cases, one or more of the central stent segment 16, proximal stent segment 22, and distal stent segment 24 may be a woven stent segment, and in some cases, it may be a knitted structure. In some cases, one or more of the central stent segment 16, proximal stent segment 22, and distal stent segment 24 may be an integral tubular structure, such as a laser-cut stent segment. In some cases, the central stent segment 16 may be sized to fit within a narrow region of the body cavity into which the medical stent 10 will be implanted. In some cases, the proximal stent segment 22 and distal stent segment 24 may each be sized to engage with the wall of the body cavity into which the medical stent 10 will be implanted.

[0055] The central stent segment 16 may be adapted to move axially (distally and proximally) relative to the proximal stent segment 22 and the distal stent segment 24 to accommodate movements within the body cavity, such as peristaltic movements, without displacing the medical stent 10. In some cases, the central stent segment 16 may be adapted to move in response to an applied force (e.g., in an axially distal direction and / or in an axially proximal direction), while the proximal stent segment 22 and the distal stent segment 24 hold the wall of the implanted body cavity in place relative to the medical stent 10. In some cases, the medical stent 10 includes a polymer coating 26 extending over the proximal stent segment 22, the distal stent segment 24, and the central stent segment 16, thereby connecting the proximal stent segment 22 and the distal stent segment 24 to the central stent segment 16. The polymer coating 26 may extend between the proximal stent segment 22 and the central stent segment 16, thereby connecting the proximal stent segment 22 to the central stent segment 16. The polymer coating 26 may extend between the distal stent segment 24 and the central stent segment 16, thereby connecting the distal stent segment 24 to the central stent segment 16. In some cases, the polymer coating 26 may be the only structure connecting the central stent segment 16 to the proximal stent segment 22 and / or the distal stent segment 24. In some cases, the polymer coating 26 may be considered as limiting how far the central stent segment 16 can translate relative to the proximal stent segment 22 and the distal stent segment 24.

[0056] In some cases, the polymer coating 26 can be configured to allow the proximal stent segment 22 to float on the proximal region 18 of the central stent segment 16 and to allow the distal stent segment 24 to float on the distal region 20 of the central stent segment 16. After implantation, the proximal stent segment 22 and / or the distal stent segment 24 can be adapted to translate relative to the central stent segment 16 in response to peristaltic forces, while the central stent segment 16 remains in place relative to the wall of the body cavity in which the medical stent 10 is implanted.

[0057] In some cases, the polymer coating 26 includes a proximal fold region 28 in which the polymer coating 26 folds itself over to allow the proximal stent segment 22 to be positioned on the proximal region 18 of the central stent segment 16. The proximal fold region 28 may define a proximal extent of the stent 10, extending proximally to both the central stent segment 16 and the proximal stent segment 22. In some cases, the polymer coating 26 includes a distal fold region 30 in which the polymer coating 26 folds itself over to allow the distal stent segment 24 to be positioned on the distal region 20 of the central stent segment 16. The distal fold region 30 may define a distal extent of the stent 10, extending distally to both the central stent segment 16 and the distal stent segment 24.

[0058] As will be further described herein, the central stent segment 16 can be axially moved relative to the proximal stent segment 22 and / or the distal stent segment 24 by lengthening the proximal folding region 28 while shortening the distal folding region 30, and / or by lengthening the distal folding region 30 while shortening the proximal folding region 28. Therefore, the axial movement of the central stent segment 16 relative to the proximal stent segment 22 and / or the distal stent segment 24 can be achieved without changing the dimensions (e.g., diameter and / or length) of any of the central stent segment 16, the proximal stent segment 22, and the distal stent segment 24.

[0059] Figures 2A to 2C An exemplary method for forming a medical stent 10 is shown. In this example, the central stent segment 16, the proximal stent segment 22, and the distal stent segment 24 have been manufactured and assembled together to form the medical stent 10. The central stent segment 16, the proximal stent segment 22, and the distal stent segment 24 can be braided, woven, or laser-cut using known techniques. The polymer coating 26 can be applied using known techniques such as spraying, dipping, etc.

[0060] exist Figure 2AIn this configuration, the central support segment 16, the proximal support segment 22, and the distal support segment 24 are positioned on the mandrel 34. It should be understood that the mandrel 34 includes a central portion 36 sized to fit the central support segment 16; a first expanded portion 38 sized to fit the proximal support segment 22; and a second expanded portion 40 sized to fit the distal support segment 24. The mandrel 34 may include a first tapered portion 42 between the first expanded portion 38 and the central portion 36. The mandrel 34 may include a second tapered portion 44 between the central portion 36 and the second expanded portion 40.

[0061] about Figure 2A Several dimensions can be specified. The central stent segment 16 has an outer diameter D1. The proximal stent segment 22 has an inner diameter D2. The distal stent segment 24 has an inner diameter D3. Dimensions D1, D2, and D3 will vary depending on the overall dimensions of the medical stent 10 and the specific intended implantation site of the medical stent 10. In some cases, taking into account the thickness of the polymer coating 26, the inner diameter D2 of the proximal stent segment 22 and the inner diameter D3 of the distal stent segment 24 may be selected relative to the outer diameter D1 of the central stent segment 16 to allow the proximal stent segment 22 and the distal stent segment 24 to be positioned on the proximal region 18 and the distal region 20 of the central stent segment 16, respectively. In some cases, for esophageal, intestinal, or weight loss applications, the outer diameter D1 of the central stent segment 16 may range from 14 mm to 25 mm. For more extensive biliary applications, D1 may range from 5 mm to 12 mm. In some cases, the inner diameter D2 of the proximal stent segment 22 may range from 15 mm to 35 mm. In some cases, such as for biliary applications, D2 can range from 6 mm to 16 mm. For example, the proximal stent segment 22 can be placed outside the bile duct, allowing for a size larger than the duct itself. In some cases, the inner diameter D3 of the stent segment 24 can range from 15 mm to 35 mm. Although the central stent segment 16 is shown as having a constant diameter, in some cases, the central stent segment 16 can be tapered.

[0062] When placed on the mandrel 34, the proximal stent segment 22 may be spaced apart from the proximal end 46 of the central stent segment 16 by a distance L1. When placed on the mandrel 34, the distal stent segment 24 may be spaced apart from the distal end 48 of the central stent segment 16 by a distance L2. In some cases, L1 and L2 may be selected to define the relative lengths of the polymer coating 26 across the distances between the proximal stent segment 22 and the central stent segment 16, and between the central stent segment 16 and the distal stent segment 24, respectively. In some cases, the values ​​of L1 and L2 define the lengths of the proximal folded region 28 and the distal folded region 30, respectively.

[0063] In some cases, L1 and L2 can influence how far the central stent segment 16 is allowed to translate relative to the proximal stent segment 22 and the distal stent segment 24 once implanted. In some cases, L1 and L2 can be chosen to be equal to each other. In some cases, if a relatively large movement between the central stent segment 16 and the proximal stent segment 22 is desired, L1 can be chosen to be greater than L2. In some cases, if a relatively large movement between the central stent segment 16 and the distal stent segment 24 is desired, L2 can be chosen to be greater than L1. In some cases, L1 and L2 can each be within the range of 10% to 50% of the length of the central stent segment 16. In some cases, for example, controlling the lengths L1 and L2 can be considered as controlling or limiting how far the central stent segment 16 is allowed to slide or translate relative to the proximal stent segment 22 and / or the distal stent segment 24.

[0064] After placing the central stent segment 16, proximal stent segment 22, and distal stent segment 24 on the mandrel 34, and ensuring appropriate spacing between the proximal stent segment 22 and the central stent segment 16, and between the central stent segment 16 and the distal stent segment 24, a polymer coating 26 can be applied, such as... Figure 2B As shown. The polymer coating 26 can be applied using known techniques such as spraying, dipping, etc. As mentioned above, the polymer coating 26 can be applied using any suitable technique such as spraying or dipping. The polymer coating 26 may have a thickness T, such as... Figure 2B As shown. In some cases, the thickness T can be selected to provide a gap between the internal dimensions of the proximal stent segment 22 and the distal stent segment 24 to allow the central stent segment 16 to move in and out of the proximal stent segment 22 and the distal stent segment 24. The thickness T of the polymer coating 26 can range, for example, from 10 micrometers to 500 micrometers. In some cases, the thickness T of the polymer coating 26 can even be greater, provided that there is sufficient gap for the central stent segment 16 to translate relative to the proximal stent segment 22 and the distal stent segment 24.

[0065] In some cases, the thickness T is constant along the length of the medical stent 10. In other cases, the thickness T of the polymer coating 26 can vary depending on its relative position on the medical stent 10. For example, the polymer coating 26 can be thicker within the proximal folding region 28 and the distal folding region 30 to better function as a movable hinge when the central stent segment 16 translates relative to the proximal stent segment 22 and the distal stent segment 24. Alternatively, the polymer coating 26 can be thinner within the proximal folding region 28 and the distal folding region 30 to be more flexible when the central stent segment 16 translates relative to the proximal stent segment 22 and the distal stent segment 24.

[0066] As can be seen, the polymer coating 26 covers the entire central stent segment 16, extending from the proximal end 46 to the distal end 48 of the central stent segment 16. In some cases, the inner diameter D2 of the proximal stent segment 22 is greater than the sum of the outer diameter D1 of the central stent segment 16 and twice the thickness T of the polymer coating 26, so as to allow not only the proximal stent segment 22 to fit onto the proximal region 18 of the central stent segment 16, but also free movement between the central stent segment 16 and the proximal stent segment 22. Similarly, the inner diameter D3 of the distal stent segment 24 is greater than the sum of the outer diameter D1 of the central stent segment 16 and twice the thickness T of the polymer coating 26, so as to allow not only the distal stent segment 24 to fit onto the distal region 20 of the central stent segment 16, but also free movement between the central stent segment 16 and the distal stent segment 24.

[0067] Forming a polymer coating 26 on the proximal stent segment 22, the central stent segment 16, and the distal stent segment 24 can be considered as forming component 50. Therefore, the polymer coating 26 can connect the proximal stent segment 22, the central stent segment 16, and the distal stent segment 24 together to define component 50. The next step is to remove component 50 from the mandrel 34, as... Figure 2C As shown. In some cases, component 50 can be flexible enough to be easily pulled away from mandrel 34. In some cases, mandrel 34 can be collapsible to facilitate easier removal of component 50. In some cases, mandrel 34 can be as follows: Figure 2A and Figure 2B The example shown is used in an expanded or inflated form, while removing component 50 from mandrel 34 only involves deflating mandrel 34.

[0068] Once component 50 has been removed from mandrel 34, the proximal stent segment 22 can be moved in the direction indicated by arrow 52 to position it on the proximal region 18 of the central stent segment 16, thereby folding the proximal folding region 28 of the polymer coating 26. The distal stent segment 24 can be moved in the direction indicated by arrow 54 to position it on the distal region 20 of the central stent segment 16, thereby folding the distal folding region 30 of the polymer coating 26. The result is a medical stent 10, for example... Figure 1 As shown in the example.

[0069] Figures 3A to 3D A schematic example is provided of how the medical stent 10 resists peristaltic movement when implanted in the esophagus 56 near a narrow region 58 within the esophagus 56. It should be understood that this is merely illustrative, as the medical stent 10 can function similarly in a variety of different body cavities. Figure 3AIn this case, the medical stent 10 can be considered to be in a relaxed state, with no particular force causing the central stent segment 16 to move relative to the proximal stent segment 22 or the distal stent segment 24, and the length of the proximal folding region 28 of the polymer coating 26 is equal to or substantially equal to the length of the distal folding region 30 (around 10 percent).

[0070] Go to Figure 3B The peristaltic force, indicated by arrow 60, tends to force the proximal stent segment 22 to move distally. The polymer coating 26 decouples the peristaltic force from the central stent segment 16. As a result of this movement, the proximal folding region 28 of the polymer coating 26 has lengthened, while the distal folding region 30 of the polymer coating 26 has shortened or ceased to fold. In some cases, the polymer coating 26 may stretch in response to the applied force, which helps the medical stent return to its relaxed shape upon removal of the applied force, such as... Figure 3C As shown.

[0071] Go to Figure 3D The reverse peristaltic force, indicated by arrow 62 (which may be caused by one or more of regurgitation or vomiting), tends to force the distal stent segment 24 to move proximally. The polymer coating 26 decouples the peristaltic force from the central stent segment 16. As a result of this movement, the distal folding region 30 of the polymer coating 26 has lengthened, while the proximal folding region 28 of the polymer coating 26 has shortened or ceased to fold. In some cases, the polymer coating 26 may stretch in response to the applied force, which helps to allow the medical stent to return to its relaxed shape upon removal of the applied force, as before. Figure 3C As shown.

[0072] In some cases, it may be sufficient for only one of the proximal stent segment 22 and the distal stent segment 24 (rather than both) to be able to translate relative to the central stent segment 16. This may be sufficient, for example, when the applied anatomical force that could cause migration is unidirectional, or when a single dynamic element, such as the proximal folding region 28 of the proximal stent segment 22 and the polymer coating 26, is sufficient to resist migration. Figure 4 This is a schematic diagram of an exemplary medical stent 64, which employs a proximal stent segment 22 connected to a central stent segment 66 via a proximal folded region 28 of a polymer coating 26. The central stent segment 66 includes a flared distal region 68 sized to engage with the wall of the body cavity to which the medical stent 64 will be implanted.

[0073] It should be understood that the medical stent 64 will be manufactured similarly to the medical stent 10, i.e., the proximal stent segment 22 is placed on the mandrel at an appropriate distance from the central stent segment 66, followed by the application of the polymer coating 26, and then the proximal stent segment 22 is removed from the mandrel and disposed on the proximal region 18 of the central stent segment 26, thereby folding the proximal folding region 28 of the polymer coating 26. Although shown and described as including the proximal stent segment 22 and the distal flaring region 68, it should be understood that a medical stent similar to the medical stent 64 may alternatively include a proximal flaring region and a distal stent segment 24.

[0074] In some cases, the proximal stent segment 22 and / or the distal stent segment 24 may include features designed to improve the stability of the medical stent within the anatomical structure. Figure 5 This is a schematic diagram of an exemplary medical stent 70. The medical stent 70 includes a central stent segment 16 extending from a proximal end 46 to a distal end 48, and includes a proximal region 18 and a distal region 20 of the central stent segment 16. The medical stent 70 includes a proximal stent segment 72 adapted to be disposed on the proximal region 18 of the central stent segment 16; and a distal stent segment 74 adapted to be disposed on the distal region 20 of the central stent segment 16.

[0075] The medical stent 70 is manufactured similarly to the medical stent 10, wherein the proximal stent segment 72, the central stent segment 16, and the distal stent segment 74 are positioned on a mandrel with appropriate spacing between them, followed by the formation of a polymer coating 26, which is then removed from the mandrel. The proximal stent segment 72 is then positioned on the proximal region 18 of the central stent segment 16 to form a proximal folded region 28, and the distal stent segment 74 is positioned on the distal region 20 of the central stent segment 16 to form a distal folded region 30.

[0076] The proximal stent segment 72 includes an annular flange 76 extending radially outward from the proximal stent segment 72. The distal stent segment 74 includes a first annular flange 78a and a second annular flange 78b, both extending radially outward from the distal stent segment 74. In some cases, the annular flange 76 may be integrally formed during the weaving, knitting, or laser cutting of the proximal stent segment 72. In some cases, the annular flange 76 may be formed separately and subsequently fixed to the proximal stent segment 72. In some cases, the annular flanges 78a and 78b may be integrally formed during the weaving, knitting, or laser cutting of the distal stent segment 74. In some cases, the annular flanges 78a and 78b may be formed separately and subsequently fixed to the distal stent segment 74.

[0077] Although the medical stent 70 is shown as having a single annular flange 76 on the proximal stent segment 72 and a pair of annular flanges 78a and 78b on the distal stent segment 74, this is merely illustrative. In some cases, the proximal stent segment 72 and the distal stent segment 74 may each include a single annular flange. In some cases, the proximal stent segment 72 and the distal stent segment 74 may each include a pair of annular flanges. In some cases, having a pair of annular flanges on at least one of the proximal stent segment 72 and the distal stent segment 74 may facilitate the orientation of the medical stent 70 within the body cavity without causing the medical stent 70 to be angularly positioned within the body cavity.

[0078] Figure 6 This is a schematic diagram of an exemplary medical stent 80. The exemplary medical stent 80 is similar to the medical stent 10, but differs in how the polymer coating is applied. Figure 6 As shown, the medical stent 80 includes a central stent segment 16 extending from a proximal end 46 to a distal end 48, and includes a proximal region 18 and a distal region 20 of the central stent segment 16. The central stent segment 16 also includes an intermediate region 82. A proximal stent segment 22 is positioned on the proximal region 18 of the central stent segment 16, and a distal stent segment 24 is positioned on the distal region 20 of the central stent segment 16. The proximal stent segment 22 may be positioned radially lateral to and spaced apart from the central stent segment 16, providing an annular space between them. Similarly, the distal stent segment 24 may be positioned radially lateral to and spaced apart from the central stent segment 16. The central stent segment 16 may extend into or through the proximal stent segment 22, and / or the central stent segment 16 may extend into or through the distal stent segment 24. In some cases, the central stent segment 16 may extend proximally to the proximal stent segment 22, and / or the central stent segment 16 may extend distally to the distal stent segment 24.

[0079] The medical stent 80 includes a polymer coating 84 extending over the proximal stent segment 22, the intermediate region 82 of the central stent segment 16, and the distal stent segment 24. The polymer coating 84 does not extend to the proximal end 46 or distal end 48 of the central stent segment 16 and is therefore not included in the folded region at the outermost end of the stent 80. Instead, the polymer coating 84 includes a proximal hinge region 86 and a distal hinge region 88, which allow the proximal stent segment 22 and the distal stent segment 24 to axially move relative to the central stent segment 16 in response to peristaltic forces. In some cases, one or more ends of the central stent segment 16 may be uncovered to facilitate drainage.

[0080] The proximal hinge region 86 of the polymer coating 84 may extend between the proximal stent segment 22 and the central stent segment 16, thereby connecting the proximal stent segment 22 to the central stent segment 16. The distal hinge region 88 of the polymer coating 84 may extend between the distal stent segment 24 and the central stent segment 16, thereby connecting the distal stent segment 24 to the central stent segment 16. In some cases, the polymer coating 84 may be the only structure connecting the central stent segment 16 to the proximal stent segment 22 and / or the distal stent segment 24. In some cases, the polymer coating 84 may be considered as limiting how far the central stent segment 16 can translate relative to the proximal stent segment 22 and the distal stent segment 24.

[0081] In some cases, the inner diameter D2 of the proximal stent segment 22 (see...) Figure 2A The outer diameter D1 of the central stent segment 16 can be larger than that of the central stent segment 16. In some cases, the inner diameter D3 of the distal stent segment 24 can be larger than the outer diameter D1 of the central stent segment 16. It should be understood that, utilizing... Figure 6 The configuration of the polymer coating 84 shown, the inner diameter D2 of the polymer stent segment 22 and the inner diameter D3 of the distal stent segment 24 can be smaller than the corresponding diameters shown for the medical stent 10, because the thickness of the polymer coating 84 does not need to be taken into account in the medical stent 80. This is because the polymer coating 84 does not extend between the outer surface of the central stent segment 16 and the inner surfaces of the proximal stent segment 22 and the distal stent segment 24. The medical stent 80 is adapted to isolate the central stent segment 16 from applied forces.

[0082] Materials that can be used for various components of the medical stents, mandrels, and their various elements disclosed herein may include those materials commonly associated with medical devices and mandrels. For simplicity, the following discussion refers to the device. However, this is not intended to limit the devices and methods described herein, as the discussion can be applied to other elements, components, parts, or devices disclosed herein, such as, but not limited to, medical stents, mandrels, filaments, anti-migration rings, coverings, and / or their elements or parts.

[0083] In some embodiments, the device and / or its components may be made of metal, metal alloy, polymer (some examples of which are described below), metal-polymer composites, ceramics, combinations thereof, or other suitable materials.

[0084] Examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), fluorinated ethylene-propylene copolymer (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-based or ester-based copolymers (e.g., polybutylene terephthalate / poly(alkylene ether) phthalate and / or other polyester elastomers, such as HYTREL® available from DuPont), polyamides (e.g., DURETHAN® available from Bayer or available from Elf...). Atochem's CRISTAMID®, elastomer polyamides, block polyamides / ethers, polyether block amides (PEBA, such as those obtained 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), polypropylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene ether (PPO), poly(p-phenylene terephthalamide) (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (e.g., available from EMS American) Grilon's GRILAMID®, perfluoro(propyl vinyl ether) (PFA), ethylene-vinyl alcohol, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS50A), polycarbonate, polyurethane silicone copolymers (e.g., ElastEon® from Aortech Biomaterials or ChronoSil® from AdvanSource Biomaterials), 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.

[0085] 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 alloys; 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: N10665 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-reinforced stainless steel; titanium; platinum; palladium; gold; combinations thereof; or any other suitable material.

[0086] In at least some embodiments, part or all of the device, and / or its components, may be doped with, made of, or otherwise comprise a radiopaque material. A radiopaque material is understood to be a material capable of producing a relatively bright image on a fluorescent screen or other imaging technique during a medical procedure. This relatively bright image helps the user of the device determine their location. Examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials filled with radiopaque fillers, etc. Furthermore, other radiopaque marking strips and / or coils may also be incorporated into the design of the device to achieve the same result.

[0087] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to the devices and / or other elements disclosed herein. For example, the device and / or its components or portions may be made of materials that substantially do not distort the image and do not produce noticeable artifacts (e.g., gaps in the image). For example, certain ferromagnetic materials may be unsuitable because they may produce MRI image artifacts. The device or portions thereof may also be made of materials that are imageable by an MRI machine. 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.), nickel-titanium, etc., and others.

[0088] In some embodiments, the devices and / or other elements disclosed herein may include suitable therapeutic agents and / or be treated with suitable therapeutic agents. Examples of suitable therapeutic agents may include antithrombotic agents (e.g., heparin, heparin derivatives, urokinase, and PPack (d-phenylalanine-proline-arginine-chloromethyl ketone)); antiproliferative agents (e.g., enoxaparin, angiopeptidase, monoclonal antibodies that block 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, vinblastine, epothilone, 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 promoters); 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.

[0089] Having described several illustrative embodiments of this disclosure, those skilled in the art will readily understand that other embodiments falling within the scope of the appended claims can also be made and used. However, it should be understood that this disclosure is illustrative in many respects only. Changes in detail may be made, particularly in terms of shape, size, arrangement of components, and exclusion and order of steps, without departing from the scope of this disclosure. The scope of this disclosure is, of course, defined by the language of the appended claims.

Claims

1. A medical stent, the medical stent comprising: A central stent segment, the central stent segment comprising a proximal region and a distal region; A proximal stent segment, the proximal stent segment being adapted to be positioned on the proximal region of the central stent segment; A distal support segment, the distal support segment being adapted to be positioned on the distal region of the central support segment; as well as A polymer coating extending over at least a portion of the central stent segment, the proximal stent segment, and the distal stent segment, the polymer coating being adapted to allow the proximal stent segment to float over the proximal region of the central stent segment and to allow the distal stent segment to float over the distal region of the central stent segment; Wherein, after implantation, the proximal stent segment and / or the distal stent segment are adapted to translate relative to the central stent segment in response to peristaltic forces.

2. The medical stent according to claim 1, wherein, The polymer coating connects the proximal stent segment and the distal stent segment to the central stent segment and limits how far the proximal stent segment and / or the distal stent segment can move relative to the central stent segment.

3. The medical stent according to any one of the preceding claims, wherein, The polymer coating extends from the proximal end of the central support segment to the distal end of the central support segment.

4. The medical stent according to any one of the preceding claims, wherein: The proximal stent segment has an inner diameter greater than the sum of the outer diameter of the central stent segment and twice the thickness of the polymer coating; and The distal support segment has an inner diameter that is greater than the sum of the outer diameter of the central support segment and twice the thickness of the polymer coating.

5. The medical stent according to claim 1 or 2, wherein, The polymer coating extends on the proximal stent segment, the central portion of the central stent segment, and the distal stent segment.

6. The medical stent according to claim 5, wherein, At least a portion of the proximal region of the central stent segment is not coated to facilitate drainage.

7. The medical stent according to claim 5 or 6, wherein: The proximal stent segment has an inner diameter larger than the outer diameter of the central stent segment; and The distal support segment has an inner diameter that is larger than the outer diameter of the central support segment.

8. The medical stent according to any one of the preceding claims, wherein, The polymer support segment includes an annular flange.

9. The medical stent according to any one of the preceding claims, wherein, The distal support segment includes one or more annular flanges.

10. The medical stent according to any one of the preceding claims, wherein: The central support segment includes a braided support segment; The proximal stent segment includes a braided stent segment; and The distal stent segment includes a braided stent segment.

11. A method of forming a medical stent, the medical stent comprising a central stent segment, a proximal stent segment adapted for positioning in a proximal region of the central stent segment, and a distal stent segment adapted for positioning in a distal region of the central stent segment, the method comprising: The proximal stent segment, the central stent segment, and the distal stent segment are mounted on a mandrel, wherein the proximal ends of the proximal stent segment and the central stent segment are spaced apart by a proximal distance, and the distal stent segment and the distal ends of the central stent segment are spaced apart by a distal distance. A polymer coating is formed extending from the proximal stent segment to the distal stent segment, the polymer coating spanning between the proximal ends of the proximal stent segment and the central stent segment, and between the distal ends of the central stent segment and the distal stent segment, to form a stent assembly; Remove the support assembly from the mandrel; The proximal stent segment is slid on the proximal region of the central stent segment, and the distal stent segment is slid on the distal region of the central stent segment to form the medical stent.

12. The method according to claim 11, wherein, The proximal distance and the distal distance are each within 10% to 50% of the length of the central support segment.

13. The method according to claim 11 or 12, wherein, Forming the polymer coating includes forming a silicone coating.

14. The method according to any one of claims 11 to 13, wherein, At least one of the proximal stent segment and the distal stent segment includes an annular flange extending radially outward from the proximal stent segment and / or the distal stent segment.

15. A medical stent, the medical stent comprising: The central support segment includes a proximal region, a flared distal region, and an intermediate central region; A proximal stent segment, the proximal stent segment being adapted to be positioned on the proximal region of the central stent segment; as well as A polymer coating extends over the proximal stent segment, the distal flare region of the central stent segment, and the intercalary central region; The polymer coating is adapted to flip itself to position the proximal stent segment on the proximal region of the central stent segment.

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