WO2025015017A1

WO2025015017A1 - Multi-directional hinging stent

Info

Publication number: WO2025015017A1
Application number: PCT/US2024/037335
Authority: WO
Inventors: Roger Labrecque; David Heim
Original assignee: Atrium Medical Corp
Current assignee: Atrium Medical Corp
Priority date: 2023-07-10
Filing date: 2024-07-10
Publication date: 2025-01-16
Anticipated expiration: 2026-01-10
Also published as: AU2024288393A1

Abstract

An expandable multi-directional hinging stent radially expands from compressed to expanded configurations. The stent includes elongated connectors and radially expandable rings (e g., at least first, second, and third rings) aligned in series along a common axis and defining a common lumen of the stent extending through the rings. The connectors extend between the rings comprising a first group including first and second elongated connectors which couple the first ring to the second ring to form a first hinging axis extending through the first and second connectors about which the stent bends in a first direction and a second group including third and fourth elongated connectors which couple the second ring to the third ring to form a second hinging axis extending through the third and fourth connectors about which the stent bends in a second direction. The first group is axially and circumferentially offset from the second group.

Description

MULTI-DIRECTIONAL HINGING STENT

Inventors: Roger LABRECQUE and David HEIM

PRIORITY CLAIM

[0001] The present disclosure claims priority to U.S. Provisional Patent Application Serial No. 63/512,877 filed July 10, 2023; the disclosure of which is incorporated herewith by reference.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

[0002] The present disclosure relates to expandable, intraluminal devices for use within a body passageway or duct and, more particularly, to implantable stents comprising one or more elongated connectors to configure the implantable stent to hinge in at least one or multiple selected directions with a relatively reduced amount of force.

Description of Related Art

[0003] A common method for treating stenosed or aneuryzed vessels or other blocked passageways is with an expandable prosthesis, such as a stent, which is configured to be deployed in the vessel or passageway in an expanded configuration to maintain patency or continuity of the vessel or passageway. Stents may also be used as fixation devices for anchoring a medical device within a vessel or passageway. Stents can be bare, coated, or covered. The cover can be constructed from a biocompatible material, such as polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePFTE). An exemplary covered stainless steel stent is the iCAST/V12 balloon expandable stent manufactured by Atrium Medical Corporation.

[0003] In many surgical procedures, a stent is configured to be delivered to a target site, expanded, and affixed in place. For example, in a fenestrated endovascular aneurysm repair (FEVAR) procedure, a number of stents may be placed within pre-formed openings or fenestrations in a main body implant or endoprosthesis to create a connection between the main body implant and target branch vessels or conduits. In vascular applications, one or more covered stents can protrude into an aortic main body implant or endoprosthesis for a few millimeters. Once deployed and affixed in place, the one or more stents create an enclosed lumen space for passage of blood from the main body implant or endoprosthesis to the target vessels. The stents can also provide increased reinforcement of the vessel wall, in order to maintain a cleared lumen or passageway.

[0004] For certain target sites and surgical procedures, the deployed stent is required to adopt a bent, curved, hinged, or twisted configuration to conform to a shape of a particular vessel, passageway, or opening between adjacent vessels or passageways. It is important that the stent is capable of adopting the bent, curved, hinged, or twisted configuration when required and without kinking or deforming to such a degree as to restrict fluid flow through a lumen of the stent. In some instances, stents can be formed from flexible materials so that the stent can be easily bent to a number of desired configurations. However, stents formed from flexible materials may not be strong enough to reinforce walls of a vessel or passageway or to resist collapsing when exposed to normal anatomical forces. As such, stents formed partially or entirely from highly flexible materials may not maintain patency or continuity of fluid flow through the passageway or vessel when deployed at a target site, and may not be suitable for use in certain surgical procedures. For example, stents formed from flexible materials may have a relatively low radial stiffness and/or axial stiffness.

[0005] Stents formed from highly flexible materials also may not be suitable for delivery using a balloon catheter. Balloon expandable stents are configured to be crimped to a balloon of a balloon catheter. During delivery, the balloon expandable stent should maintain adequate retention to the catheter so as not to become dislodged until expanded at the target site. Particularly, balloon expandable stents should demonstrate the ability to be delivered and positioned accurately without extensive foreshortening or “watermelon seeding,” where the stent unexpectedly slides off of the proximal or distal end of the balloon. The stent should also be designed with predictable recoil properties after deployment to maintain proper wall apposition. For example, stents that are placed in fenestrations must be strong enough to resist migration of the associated endograft and not collapse due to shear forces. Stents formed from highly flexible materials may not be capable of remaining in place when crimped to a balloon catheter or when deployed within a fenestration.

[0006] Many different stent designs are known to those skilled in the art. Known stent designs can include combinations of different types of framing structures, such as helical coils, meshes, lattices, or interconnected rings. Such framing structures can be made from, for example, stainless steel and/or cobalt chromium. In one common design, a stent can include a series of cylindrical rings aligned in a series along a central longitudinal or common axis. The rings can be fixedly secured to one another by a plurality of elongated connectors, such as longitudinally extending struts. Stents formed from rings and elongated connectors may have sufficient radial strength to support a vessel wall, but may not be sufficiently flexible to be deployed in a curved or bent configuration. There are also designs where connectors attach via a loose press fit, so that connectors have more freedom of movement. In other examples, stent designs include drill holes in the stent struts to make them more flexible. However, there is a need for alternative stent designs that are sufficiently flexible to adopt certain bent, curved, hinged, or twisted configurations when required, while remaining sufficiently rigid to be crimped to a balloon catheter, support or reinforce a vessel or passageway, and resist migration from a target site or deployment location.

SUMMARY OF THE DISCLOSURE

[0007] According to an aspect of the disclosure, an expandable multi -directional hinging stent configured to radially expand from a compressed configuration to an expanded configuration includes a plurality of radially expandable rings aligned in series along a common axis and defining a common lumen of the stent extending through the plurality of rings. The plurality of rings comprises at least a first ring, a second ring, and a third ring aligned in series. The stent also includes a plurality of elongated connectors extending between the plurality of rings. The connectors include a first group of at least two elongated connectors extending between the first ring and the second ring that form a first hinging axis about which the stent is configured to bend in a first direction. The connectors also include a second group of at least two elongated connectors extending between the second ring and the third ring that form a second hinging axis about which the stent is configured to bend in a second direction. The first group of elongated connectors is axially and circumferentially offset from the second group of elongated connectors. [0008] According to another aspect of the disclosure, an expandable stent configured to radially expand from a compressed configuration to an expanded configuration includes a plurality of radially expandable rings aligned in series along a common axis and defining a common lumen of the stent extending through the plurality of rings. The stent also includes a plurality of elongated connectors extending between the plurality of rings comprising at least a first pair of elongated connectors extending between a particular ring and an immediately adjacent ring and a second pair of elongated connectors extending between the particular ring and the immediately adjacent ring. The elongated connectors of each pair are spaced apart from each other by less than 90 degrees about a circumference of the stent and the elongated connectors of the first pair are circumferentially spaced apart from the elongated connectors of the second pair by more than 90 degrees.

[0009] Non-limiting illustrative examples of embodiments of the present disclosure will now be described in the following numbered clauses:

[0010] Clause 1 : An expandable multi-directional hinging stent configured to radially expand from a compressed configuration to an expanded configuration, the expandable stent comprising: a plurality of radially expandable rings aligned in series along a common axis and defining a common lumen of the expandable stent extending through the plurality of rings, wherein the plurality of rings comprises at least a first ring, a second ring, and a third ring aligned in series; and a plurality of elongated connectors extending between the plurality of rings comprising (i) a first group including a first elongated connector and a second elongated connector, the first and second connectors coupling the first ring to the second ring to form a first hinging axis extending through the first and second connectors about which the expandable stent is configured to bend in a first direction and (ii) a second group including a third elongated connector and a fourth elongated connector, the third and fourth connectors coupling the second ring to the third ring to form a second hinging axis extending through the third and fourth connectors about which the expandable stent is configured to bend in a second direction, wherein the first group of elongated connectors is axially and circumferentially offset from the second group of elongated connectors. [0011] Clause 2: The expandable stent of clause 1, wherein the first group of elongated connectors is positioned such that a bending force required to bend the stent at the first hinging axis by a predetermined distance in the first direction is less than a bending force required to bend the stent at the first hinging axis by the predetermined distance in the second direction.

[0012] Clause 3: The expandable stent of clause 1, wherein the second group of elongated connectors is positioned such that a bending force required to bend the stent at the second hinging axis by a predetermined distance in the second direction is less than a bending force required to bend the stent at the second hinging axis by the predetermined distance in the first direction.

[0013] Clause 4: The expandable stent of clause 1, wherein the first and second elongated connectors are immediately adjacent to one another and are circumferentially spaced apart by at least 90 degrees about a circumference of the stent.

[0014] Clause 5: The expandable stent of clause 1, wherein the elongated connectors of the first group are circumferentially offset from the elongated connectors of the second group by between 60 degrees and 90 degrees about a circumference of the stent.

[0015] Clause 6: The expandable stent of clause 1, wherein the first and second elongated connectors are one of circumferentially spaced apart from each other by less than 90 degrees about a circumference of the stent or are circumferentially spaced apart from one another by at least 90 degrees about the circumference of the stent.

[0016] Clause 7: The expandable stent of clause 6, wherein the first group of elongated connectors includes a fifth elongated connector and a sixth elongated connector spaced from one another circumferentially in a manner symmetrical to the first and second elongated connectors about the common axis of the stent.

[0017] Clause 8: The expandable stent of clause 6, wherein the third and fourth elongated connectors are one of circumferentially spaced apart from each other by less than 90 degrees about the circumference of the stent and circumferentially spaced apart from one another by at least 90 degrees about the circumference of the stent.

[0018] Clause 9: The expandable stent of clause 1, wherein the plurality of elongated connectors comprises at least one of a bent portion, a curved portion, a straight portion, or a pigtailed portion.

[0019] Clause 10: The expandable stent of clause 1, wherein at least one of the plurality of rings or the plurality of elongated connectors comprises a biocompatible alloy, a biocompatible polymer, or a bioabsorbable material.

[0020] Clause 11 : The expandable stent of clause 1, wherein at least one of the plurality of rings or the plurality of elongated connectors comprises stainless steel, cobalt chromium, or a nickel-titanium alloy.

[0021] Clause 12: The expandable stent of clause 1, further comprising a cover over at least a portion of the plurality of rings, wherein the cover comprises polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE).

[0022] Clause 13: The expandable stent of clause 1, wherein each of the plurality of rings comprises multiple linear segments connected together end-to-end forming peaks and valleys of the ring.

[0023] Clause 14: The expandable stent of clause 13, wherein at least one of the plurality of elongated connectors is connected to one of the plurality of rings at a substantially middle point of the linear segment of the ring between the peaks and valleys of the ring.

[0024] Clause 15: The expandable stent of clause 13, wherein the plurality of elongated connectors is arranged forming two axially extending spirals through the plurality of rings, and wherein: the first and second elongated connectors are circumferentially offset by at least one linear segment from the third and fourth elongated connectors; and connection points on the second ring for the first and second elongated connectors are circumferentially offset from connection points on the second ring for the third and fourth elongated connectors that extend to the third ring.

[0025] Clause 16: The expandable stent of clause 13, wherein at least one of the plurality of elongated connectors is connected to one of the plurality of rings at a point on the linear segment closer to one of the peak or the valley of the ring than to the other of the peak or the valley of the ring.

[0026] Clause 17: The expandable stent of clause 13, wherein at least one of the elongated connectors comprises an angled section that is angled relative to the common axis of the stent, an end of the angled section connecting the elongated connector to the linear segment.

[0027] Clause 18: The expandable stent of clause 17, wherein each of the first and second elongated connectors comprises a first end connected to one of the linear segments of the first ring and a second end connected to one of the linear segments of the second ring that is not axially aligned with the linear segment of the first ring to which the first end is attached.

[0028] Clause 19: The expandable stent of clause 1, further comprising at least one rigid section comprising: a plurality of radially expandable rings of the rigid section that are aligned in series along the common axis and defining a portion of the common lumen of the stent; and a plurality of elongated connectors extending between rings of the plurality of rings of the rigid section, wherein at least three elongated connectors extend between each ring and an immediately adjacent ring of the plurality of radially expandable rings of the rigid section, each elongated connector being separated from each immediately adjacent elongated connector by no more than 120 degrees.

[0029] Clause 20: An expandable stent configured to radially expand from a compressed configuration to an expanded configuration, the expandable stent comprising: a plurality of radially expandable rings aligned in series along a common axis and defining a common lumen of the expandable stent extending through the plurality of rings; and a plurality of elongated connectors extending between the plurality of rings comprising at least a first pair of elongated connectors extending between a first one of the plurality of rings and a second one of the plurality of rings immediately adjacent to the first ring and a second pair of elongated connectors extending between the first ring and the second ring, wherein the elongated connectors of each pair are spaced apart from each other by less than 90 degrees about a circumference of the expandable stent and the elongated connectors of the first pair are circumferentially spaced apart from the elongated connectors of the second pair by more than 90 degrees.

[0030] These and other features and characteristics disclosed herein, as well as the methods of operation and functions of the related elements of structures and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description and appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the disclosure or any invention. As used in the specification and the claims, the singular form of “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1A is a side view of a stent in an expanded configuration, according to an aspect of the present disclosure;

[0032] FIG. IB is a flattened view of a stent shown two-dimensionally including both a flexible portion and a rigid portion, according to an aspect of the present disclosure;

[0033] FIG. 1C is a side view of a covered stent in a compressed configuration, according to an aspect of the present disclosure;

[0034] FIG. ID is a side view of a stent in a compressed configuration, according to an aspect of the present disclosure;

[0035] FIG. IE is a side view of the front, semicircular portion of the stent of FIG. ID (wherein the back, semicircular portion of the stent has been removed for clarity); [0036] FIG. IF is a cross-section of the stent of FIG. ID passing through the connectors.

[0037] FIG. 2A is a flattened view of a flexible portion of a stent, according to an aspect of the present disclosure;

[0038] FIG. 2B is a graph comparing the bending response for a conventional stent (in this case, the iCAST/V12 stent design, sold by Atrium Medical Corporation) compared to the bending response of the flexible portion of the stent of FIG. IB in its expanded configuration;

[0039] FIG. 3 is a side view of a stent including the flexible portion of FIG. IB bent about a hinging axis, according to an aspect of the present disclosure;

[0040] FIG. 4A is a flattened view of another flexible portion of a stent, according to an aspect of the present disclosure;

[0041] FIG. 4B is a graph comparing the bending response for a conventional stent compared to the bending response of the flexible portion of the stent of FIG. 4A in its expanded configuration;

[0042] FIG. 5 is a flattened view of another flexible portion of a stent, according to an aspect of the disclosure;

[0043] FIG. 6 is a flattened view of another flexible portion of a stent, according to an aspect of the disclosure;

[0044] FIG. 7 is a flattened view of another flexible portion of a stent, according to an aspect of the disclosure;

[0045] FIG. 8A is a flattened view of another flexible portion of a stent, according to an aspect of the disclosure;

[0046] FIG. 8B is a graph comparing the bending response for a conventional stent compared to the bending response of the flexible portion of the stent of FIG. 8 A in its expanded configuration;

[0047] FIG. 9 is a flattened view of another flexible portion of a stent, according to an aspect of the disclosure;

[0048] FIGS. 10A-10D are flattened views of different elongated connectors extending between expandable rings of a stent, according to aspects of the disclosure;

[0049] FIGS. 11A-1 ID are flattened views of additional embodiments of elongated connectors extending between expandable rings of a stent, according to an aspect of the disclosure;

[0050] FIG. 12 is a flattened view of expandable rings of a stent connected together by a strut, according to an aspect of the disclosure;

[0051] FIG. 13 is a flattened view of expandable rings of a stent directly connected together, according to an aspect of the disclosure;

[0052] FIG. 14 is a flow chart showing a method for deploying a stent, according to an aspect of the disclosure;

[0053] FIG. 15A is a computer generated representation showing a conventional stent bent in a cantilever test;

[0054] FIG. 15B is a computer generated representation showing a flexible portion of a stent including features of the present disclosure bent in a cantilever test;

[0055] FIGS. 16A-16E are photographs of prototype stents including features of the present disclosure bent or twisted to show enhanced flexibility provided by the stent designs disclosed herein;

[0056] FIG. 17 is a flattened view of another flexible portion of a stent, according to an aspect of the present disclosure;

[0057] FIG. 18 is a flattened view of another flexible portion of a stent, according to an aspect of the present disclosure;

[0058] FIG. 19 is a flattened view of another flexible portion of a stent, according to an aspect of the present disclosure; and

[0059] FIG. 20 is a cross-sectional front view of a stent showing an initial or 0 degree position, a 90 degree position, a 180 degree position, a 270 degree position and a 360 degree position around the stent, according to an aspect of the present disclosure.

DESCRIPTION OF NON-LIMITING EMBODIMENTS OF THE DISCLOSURE [0060] The illustrations generally show illustrative and non-limiting aspects of the devices, assemblies, and methods of the present disclosure. While the descriptions present various aspects of the devices and assemblies, it should not be interpreted in any way as limiting the disclosure. Furthermore, modifications, concepts, and applications of the disclosure’s aspects are to be interpreted by those skilled in the art as being encompassed by, but not limited to, the illustrations and descriptions herein.

[0061] Further, for purposes of the description hereinafter, the terms “end”, “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, “radial”, and derivatives thereof shall relate to the disclosure as it is oriented in the drawing figures. The term “proximal” refers to an end of the device that is configured to be manipulated by a user or, for an implanted device, the side or end of the device that remains closest to the implantation site, when the device is deployed. The term “distal” refers to the end of the device opposite from the proximal end, which can be the end of the device farthest away from portions of the device intended to be manipulated by a user. For an implanted device, the “distal” end of the device is the end of the device farthest away from the implantation site. However, it is to be understood that the disclosure may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary aspects of the disclosure. Hence, specific dimensions and other physical characteristics related to the aspects disclosed herein are not to be considered as limiting. For the purpose of facilitating understanding of the disclosure, the accompanying drawings and description illustrate preferred aspects thereof, from which the disclosure, various aspects of its structures, construction and method of operation, and many advantages may be understood and appreciated.

[0062] For the purposes of this disclosure, the term “about” refers to a range of ± 10% of the stated value.

[0063] With reference to the figures, the present disclosure is directed to an expandable stent 10 with a multi-directional hinging mechanism that allows the stent 10 to hinge, bend, or flex in multiple directions and/or that allows different portions of the stent 10 to hinge, bend, or flex in multiple directions. As is common for expandable stents known in the art, the stent 10 of the present disclosure can be radially expanded using, for example, an expandable catheter, such as a dilating or balloon catheter. While the stents 10 being expandable are often used for endovascular procedures, such as Fenestrated Endovascular Aortic Repair (FEVAR), Branched Endovascular Aortic Repair (BEVAR), chimney Endovascular Aortic Repair (ChEVAR), peripheral, coronary, bilary, or other stenting procedures, it is understood that the arrangements of the stents 10 disclosed herein are not limited to use with endovascular procedures. For example, the stent designs disclosed herein can be adapted for use in any number of medical applications and procedures in which a stenting structure could be used to maintain fluid flow through a body lumen and/or for positioning of a medical device within a body lumen. For example, medical devices including implantable grafts, drug delivery devices, filters, shunts, and similar medical devices could all be modified to include the arrangements of expandable rings, elongated connectors, and/or struts of the present disclosure. Furthermore, stent designs of the present disclosure may be deployed in other structures besides blood vessels, such as the small intestine, large intestine, biliary ducts, or any other anatomical site.

[0064] As shown in FIGS. 1A-1F, the stents 10 of the present disclosure may include a tubular structure that can be coated, covered, partially covered, fully encapsulated, partially encapsulated, or uncovered. In some examples, the members, tines, rings, and/or struts of a flexible portion 12 and/or a rigid portion 14 of the stent 10 can be cut from a continuous tube by an automated cutting process, such as laser cutting. In some instances, portions of the stent 10 can also be formed by connecting separate elongated members together and/or to other elements of the stent 10 to form a tubular structure. For example, elongated members can be connected together or to other elements of the stent 10 by ultrasonic welding, laser welding, or another suitable connecting process. Also, a plurality of tines or elongated members of the stent 10 may be woven together to form portions of the stent 10. Dimensions of the stent 10, such as a longitudinal length LI (shown in FIG. 1A) of the stent 10, a length L2 of the flexible portion 12, a length L3 of the rigid portion 14 of the stent 10, a compressed diameter D2 (shown in FIGS. ID and IE) of the stent 10, an expanded diameter DI (shown in FIG. 1A) of the stent 10, etc., can be selected based on various considerations including, but not limited to, the intended deployment location, intended delivery assembly and technique, and/or intended manner of use for the stent 10.

[0065] As described in detail herein, the hinging mechanism of the present disclosure refers to portions of the stent 10 having, in a selected direction, reduced bending or flexural stiffness compared to other portions of the stent 10 and/or compared to conventional stent designs, while maintaining sufficient radial stiffness and axial stiffness (e.g., column strength) to fulfill its intended purpose. The reduced bending stiffness may relate to a reduced amount of force required to bend, curve, or hinge the stents 10 in a given direction. It is noted that the type of movement among bending, curving, and hinging will be understood by one skilled in the art such that these terms will be used interchangeably herein. The reduced bending stiffness may be relative to a variety of perspectives such as those just noted. For example, with regard to bending in a selected direction, the stents 10 may have portions designed to have the reduced bending stiffness such that the stents 10 can bend in the selected direction (e.g., around a bending axis passing through two diametrically connected connectors 16 that connect adjacent tubular sections of the stent 10 wherein the adjacent tubular sections are separated from one another by gaps offset circumferentially from the bending axis by 90 degrees at these portions with a reduced amount of force as opposed to other portions that require a greater amount of force. In another perspective, the reduced bending stiffness may be relative to a circumference of the stents 10. For example, within a selected circumference, the stents 10 may have a reduced bending stiffness in one bending direction over another bending direction. As will be described in further detail below, the reduced bending stiffness may be achieved by creating a hinging axis that reduces the force required for the stents 10 to hinge about the hinging axis over a different axis other than the hinging axis. The stents 10 disclosed herein are configured to have sufficient radial stiffness to maintain patency of a body passageway or vessel, when the stent 10 is deployed in the body lumen and exposed to normal body forces at the deployment location. Each stent 10 disclosed herein is also configured to have sufficient axial stiffness to substantially maintain a length of the stent 10 during manufacturing (e.g., easier processing to manufacture the stent with an increased successful production rate), during delivery (e.g., increased column strength to accommodate for forces encountered during delivery to a target site), and/or during deployment (e.g., lower and more predictable foreshortening).

[0066] As used herein, “bending stiffness” or “flexural stiffness”, which are used interchangeably herein, refers to a structural member’s resistance to deflection, such as deflection that occurs when a load is applied orthogonal to the axial direction at the free end of a structural member, as in a tip-loaded cantilever beam. A stent 10 with high bending stiffness requires greater force to displace an end of the stent 10 by a specified distance compared to a stent 10 that is more flexurally compliant. The bending stiffness of an elongated member, such as a beam or stent, can be measured by a cantilever bend test. One skilled in the art will recognize that stents that have high bending stiffness are more likely to kink when forced to bend compared with stents that are more flexurally compliant. The forces applied to the stents 10 that cause the stents 10 to bend may be dependent upon a variety of factors. For example, as those skilled in the stent manufacturing art will understand, the material of the stents 10 or components thereof may contribute to the bending stiffness and subsequently the force required to bend the stents 10. As will be described in further detail below, the configuration of the components of the stents 10 may also contribute to the bending stiffness, particularly when the configuration allows for a relatively reduced amount of force to be required to bend the stents 10.

[0067] By contrast, “radial stiffness” refers to resistance to deformation when a radially inwardly directed force is applied to a sidewall of the stent 10. A stent 10 with low radial stiffness may deform, compress, or collapse when radially inwardly directed forces, such as radially inwardly directed forces from a constricting or collapsing passageway or vessel, are applied to a sidewall of the stent 10. The stents 10 of the present disclosure are configured to have sufficient radial stiffness to avoid radial collapsing or radial compressing when the body passageway in which the stent is deployed constricts around the stent 10 so that fluid flow through a lumen of the stent 10 is preserved. The radial forces to which the stent 10 may be exposed during normal use can be determined by those skilled in the stent manufacturing art and will vary based on the intended deployment location and/or use of the stent 10. Accordingly, in accordance with the principles of the present disclosure, those skilled in the art may modify the geometric configuration, materials, and other characteristics of the stents 10 disclosed herein to obtain sufficient radial stiffness so that the stent 10 fulfills its intended purpose.

[0068] As also used herein, “axial stiffness” refers to resistance to compression or stretching along a given axis. In a particular manner, the axial stiffness along a main longitudinal axis of the stent 10, 110 (e.g., a central axis of a lumen of the stent 10) may be referred to as a column strength, with particular regard to resisting compression along the main longitudinal axis. The stents 10, 110 of the present disclosure are configured to have sufficient axial stiffness or column strength to prevent an overall length of the stents 10, 110 from substantially changing during the various stages discussed above. The axial forces to which the stents 10, 110 may be exposed during normal use can be determined by those skilled in the stent manufacturing art and will vary based on the intended deployment location and/or use of the stents 10, 110. Accordingly, in accordance with the principles of the present disclosure, those skilled in the art may modify the geometric configuration, materials, and other characteristics of the stents 10, 110 disclosed herein to obtain sufficient axial stiffness or column strength so that the stent 10, 110 fulfills its intended purpose.

[0069] In some examples, the stents 10 of the present disclosure comprise multiple hinging mechanisms, such as hinging mechanisms between different rings of the stent 10, that allow the stent 10 to hinge, flex or bend in different directions with a relatively reduced amount of force. [0070] As will be described in further detail below, the hinging mechanism may correspond to creating a hinging axis through the stent 10 based on a positioning of the hinging mechanism circumferentially and/or longitudinally along the stent 10. Including multiple hinging mechanisms or portions provides a stent 10 with a multi-directional hinging ability meaning that different portions of the stent 10 are configured to bend more easily in different selected directions so that the stent 10 can be deployed in a variety of positions and configurations. The stent 10 may therefore be configured to adopt non-linear shapes such as when deployed at a target location that requires the stent 10 to accommodate a bent, curved, or hinged configuration. As used herein, “bends more easily” means that a bending force required to bend or hinge the stent 10 by a predetermined distance in one direction is less than a bending force required to bend or hinge the stent 10 in another direction. That is, the stent 10 may bend more easily due to a relatively reduced amount of force. Accordingly, for a stent 10 with multiple hinging mechanisms, the stent 10 can be capable of bending more easily in many directions. In particular, the multi-dimensional hinging mechanism allows the stent 10 to bend or flex in multiple directions without kinking, thereby preventing a restriction of fluid flow through a lumen of the stent 10. By avoiding or resisting kinking, the stent 10 can be deployed in various or multiple bent or curved configurations without restricting fluid flow through the stent 10 or reducing the ability of the stent 10 to maintain patency of the blood vessel.

[0071] In order to provide radial stiffness, axial stiffness, and kink resistance, the stents 10 disclosed herein include various geometric arrangements of expandable rings 18, elongated connectors 16, and/or struts positioned to provide proper support for the rings 18 to prevent the stent 10 from collapsing (e.g., maintaining radial and axial integrity), while allowing easy bending in selected directions or multiple directions (e.g., maintaining flexibility). Hinge points of the stent 10 can be selectively positioned for different rings 18 (e.g., through circumferential offset on the rings 18) creating the multi -directional hinging stent 10 that provides enhanced stent flexibility in multiple directions or in any desired direction and which reduces bending stiffness of the stent 10 in these multiple directions when compared to conventional stent designs, and allowing for the stent 10 to hinge or bend in all directions because each direction may be achieved through a corresponding positioning of the elongated connectors 16 around the rings 18. Also, the stents 10 disclosed herein are configured to provide predictable recoil properties after deployment so as to maintain proper wall apposition. In particular, stents 10 of the present disclosure that are placed in fenestrations should be strong enough to resist migration of the associated endo-graft and not collapse due to shear forces.

[0072] The stents 10 comprising the multi-directional hinging mechanism disclosed herein can also be configured to address certain difficulties encountered during delivery of conventional stents. As previously described, a balloon expandable stent is typically delivered using a balloon catheter to which the stent 10 is crimped. During delivery, the stent 10 should be configured to maintain adequate stent retention to the catheter so as not to become dislodged during placement. Further, balloon expandable stents 10 should be configured to be delivered and positioned accurately without extensive foreshortening. The stents 10 of the present disclosure, which are configured to flex or bend in multiple directions, can be easily and tightly crimped to a balloon expandable catheter reducing the likelihood that the stent 10 will be become dislodged or slide off of the catheter during placement.

[0073] FIGS. 1A-1F show a non-limiting, exemplary expandable stent 10 that is provided with the multi-directional hinging mechanism in accordance with the present disclosure. The stent 10 is configured to radially expand from a radially retracted or compressed configuration (e.g., FIGS. ID and IE) to a radially expanded configuration (e.g., FIG. 1A). The stent 10 comprises a first or proximal end 2 and a second or distal end 4. The stent 10 can comprise one or more flexible segments or flexible portion(s) 12 that is configured to hinge at a predetermined position and about a hinging axis. As used herein, the “flexible portion” can refer to a portion of the stent 10 having a configuration allowing multi-directional hinging between the rings 18 selected so that the stent 10 bends more easily in selected directions than if the configuration according to the present disclosure was not present. By contrast, the previously described conventional stents are often flexurally rigid (e.g., have a high bending stiffness) and resist bending in any direction and/or require substantially equal force to bend in any direction where that force is greater than the force the stent 10 may require to bend about the hinging axis. In accordance with the present disclosure, the flexible portion(s) 12 can be arranged so that different portions or segments of the stent 10 bend more easily in different directions, thereby producing the multi-directional hinging stent of the present disclosure that bends easily in multiple directions. That is, the stent 10 may be configured with a stent design for the flexible portion(s) 12 to bend in predetermined directions, at predetermined locations along the stent 10, and in one or more directions due to the reduced amount of force that is required for the stent 10 to bend in the predetermined directions, at the predetermined locations, and in the one or more directions. The multi -directional hinging allows the stent 10 to be deployed in a wide variety of positions and configurations conforming, for example, to the geometry of a portion of a body lumen within which the stent 10 is to be deployed. When deployed, the stent 10 is configured to maintain an intended radial structure by providing a radial stiffness so that fluid flow through a lumen of the stent 10 is not obstructed when the stent 10 is exposed to normal body forces at the deployment location. As previously described, “radial stiffness” refers to resistance to radial deformation. A stent 10 with reasonable radial stiffness is able to resist collapsing and/or to maintain a shape and cross-sectional area even when external forces (e.g., forces created by a restricting or collapsing vessel or artery) constrict around the stent 10. In particular, the stents 10 disclosed herein should be sufficiently strong so that fluid flow through a lumen of the stent 10 is not substantially reduced or obstructed even when the body passageway or vessel in which the stent 10 is deployed begins to contract or collapse, such as may occur do to intimal hyperplasia and/or connective tissue remodeling and/or inflammatory cell infiltration following stent placement.

[0074] The stent 10 may also include one or more rigid sections or rigid portions 14 (shown in FIG. IB) connected to and axially aligned with the flexible portions 12. As used herein, a “rigid portion” of the stent 10 refers to a portion of the stent 10 having a configuration selected to resist bending in many directions and/or to portions or segments of the stent 10 where a similar force is needed to bend the stent 10 in different directions. The rigid portion may substantially correspond to a rigid design of conventional stents with rings and connectors where the rigid design instead extends through the entire conventional stent. In contrast, the stent 10 may selectively incorporate one or more of the rigid portions 14 within the overall stent with the intent of preventing or reducing bending at these segments of the stent 10. A non-limiting example of a stent 10 comprising both a flexible portion 12 and a rigid portion 14 is shown in FIG. IB. The flexible portion 12 comprises multiple axial or elongated connectors 16 or struts that are arranged to resist bending. For example, relative to a section of the flexible portions 12, the rigid portion 14 may comprise a greater number of the elongated connectors 16. By contrast, as will be described in further detail below, the flexible portion 12 includes fewer elongated connectors 16 that are arranged to resist bending in one or more first directions by requiring a greater amount of force before bending occurs (e.g., in an amount similar to the rigid portion 14), while permitting bending in one or more second directions different than the first directions upon application of an amount of force reduced relative to the force required to bend the flexible portion 12 in the first direction(s).

[0075] The flexible portion(s) 12 and rigid portion(s) 14 of the stent 10 are generally formed from the same material. For example, the flexible portion(s) 12 and rigid portion(s) 14 can comprise members, tines, rings, and/or struts formed from suitable metal materials, such as stainless steel or cobalt chromium. The flexible portion 12 and/or rigid portion 14 can also comprise biocompatible polymers, absorbable polymers, bioabsorbable materials, and/or other biomaterials, as are known in the art. The portion(s) 12, 14 of the stent 10 may also be formed from a super-elastic material. An exemplary super-elastic material commonly used in the stent art is nickel titanium alloy (e.g., NITINOL). As is known in the art, NITINOL also has shapememory properties that permit a memorized shape to be imprinted on NITINOL-containing structures so that these structures will revert to the memorized shape or configuration when the material is activated (e.g., by being heated to a particular temperature (e.g., body temperature)). However, shape-memory properties are not required for the present invention. Instead, NITINOL and similar materials may also be used with the stents 10 disclosed herein to take advantage of these materials’ super-elasticity and enhanced flexibility, which may be beneficial for certain uses of the stents 10 disclosed herein. As noted above, the materials used for the elongated connectors 16 may define an amount of force required to bend the stent 10 in a given direction and this amount may vary based on the direction of bending.

[0076] In many cases, the flexible portion(s) 12 and the rigid portion(s) 14 of the stent 10 are formed by laser cutting selected geometric patterns from a single tubular structure. In such cases, the flexible portion(s) 12 and rigid portion(s) 14 of the stent 10 are integrally formed and differ only in the orientation of the elongated connectors 16 and other geometric features of the stent 10. In other examples, the flexible portion(s) 12 and rigid portion(s) 14 can be formed as separate structures that are connected together using, for example, ultrasonic welding, adhesives, suturing, or other commonly used connecting techniques, as are known in the stent manufacturing art.

[0077] With continued reference to the non-limiting embodiments of the disclosure shown in FIGS. 1A-1F, the stent 10 can comprise multiple radially expandable rings 18 aligned in series along a common axis XI to define a common lumen 20 of the stent 10 extending through the rings 18. Within the stent 10, the flexible portion(s) 12 and the rigid portion(s) 14 can comprise the rings 18. The rings 18 can be circular in shape defining a cylindrical shape for the lumen 20. In other examples, one or more of the rings 18 can be shaped as an oval, triangle, square, rectangle, polygon, or any other convenient regular or irregular shape, such that the lumen 20 has a corresponding cross-sectional shape along the axis XI. The rings 18 can be fully annular members that fully enclose the lumen 20 of the stent 10 or can include a gap or opening at one or more locations around a circumference of the ring 18. Gaps or openings of the multiple rings 18 of the stent 10 can be aligned axially along a length of the stent 10 or can be offset from one another.

[0078] In some examples, the rings 18 comprise multiple segments 22 connected together end- to-end forming a substantially repeating pattern of peaks 24 and valleys 26 of the ring 18. The segments 22 can be linear, arcuate, serpentine, or other configurations. As used herein, “substantially repeating” segments 22 can refer to units that are repeating, but could accommodate minor interruptions in the repeating pattern. Minor interruptions in the repeating pattern can be, for example, changes or substitutions to the repeating segments 22 of the ring(s) 18 that do not affect expansion of the ring(s) 18. For example, some segments 22 could be formed from curved portions (e.g., rather than connected straight segments). Also, some segments 22 could be longer or shorter than other segments 22 of the ring(s) 18. Thus, the arrangement of segments 22 of the rings 18 shown in FIGS. 1A-1F are not intended to be limited to a strict and exact repeating pattern of segments 22. For example, a ring 18 that includes repeating segments 22, but with one or several minor interruptions to the repeating pattern, is considered to be within the scope of the present disclosure.

[0079] Each of the rings 18 in FIGS. 1A-1F include sixteen segments 22 defining eight peaks 24 and eight valleys 26 per ring 18. However, the number of segments 22, peaks 24, and valleys 26 is not intended to be limiting, and rings 18 can have any number of segments 22 (e g., fewer than sixteen or more than sixteen segments 22) within the scope of the present disclosure. Further, in some examples, different rings 18 of the stent 10 may include different numbers of segments 22. For example, rings 18 near a middle of the stent 10 may include sixteen segments 22, while rings 18 near ends 2, 4 of the stent 10 may include more segments (e.g., up to twenty or more segments 22 per ring 18). While rings 18 can be provided in a wide variety of configurations and orientations, for simplicity, as used herein, peaks 24 of the ring 18 refer to portions of the ring 18 closer to the proximal end 2 of the stent 10. Valleys 26 refer to portions of the ring 18 that are closer to the distal end 4 of the stent 10. When the stent 10 is in the radially compressed (e.g., crimped) configuration (FIGS. ID and IE), the rings 18 are radially compressed, meaning that a diameter D2 of the ring 18 is relatively smaller, and an amplitude of the ring 18 (e.g., an axial distance between a peak 24 and a valley 26 of the ring 18) is relatively larger as compared to a radially expanded configuration. For example, the diameter D2 of the stent 10 in the compressed state can be about 1.5 mm to about 4.0 mm. The amplitude of the rings 18 in the compressed state can be about 2 mm to about 4 mm. As the stent 10 transitions from the radially compressed state to the radially expanded state (shown in FIG. 1A), the diameter DI of the ring 18 increases while the amplitude between the peaks 24 and valleys 26 of the ring 18 decreases. For example, the diameter DI of the rings 18 of the stent 10 may increase by 2.0 mm, 4.0 mm, 8.0 mm or more, as the stent 10 is expanded. For example, the amplitude of the rings 18 in the expanded state can be about 1.0 mm to about 4.0 mm.

[0080] The rings 18 of the stent 10 can be arranged in a variety of configurations, as are known in the art. In some examples, as shown in FIGS. 1A-1F, rings 18 are arranged in a “peak- to-valley” configuration, where a peak 24 of a first one of the rings 18 is axially aligned or substantially aligned with a valley 26 of a second one of the rings 18 immediately adjacent to the first ring 18. As used herein, a first ring is “immediately adjacent” to a second ring when there are no other rings between the first ring and the second ring. It is understood that there may be other structural elements (e.g., elongated connectors, struts, portions of a cover) between the first ring and the second ring. As used herein, “axially aligned” refers to points on different rings 18 of the stent 10 that are co-linear (i.e., on the same line) along a line that is parallel to the common axis XI of the stent 10.

[0081] In other examples, the rings 18 can be arranged “peak-to-peak”, where a peak 24 of a particular ring 18 is axially aligned with a peak 24 of an immediately adjacent ring 18. Thus, in comparison to the “peak-to-valley” configuration, the “peak-to-peak” configuration may arrange the rings 18 so that a line may pass through the peaks 24 in consecutive ones of the rings 18 that is parallel to the axis XI. A line passing through the valleys 26 in consecutive ones of the rings 18 is also parallel to the axis XI. In other examples, peaks 24 and valleys 26 of a particular ring 18 (or rings) can be circumferentially offset from (e.g., not aligned with) both peaks 24 and valleys 26 of an immediately adjacent ring 18, such that the particular ring 18 is said to be offset from the immediately adjacent ring 18 (e.g., in an offset configuration). In some examples, all rings 18 of the stent 10 can be arranged in the same orientation (e.g., all rings 18 are peak-to- peak or all rings 18 are peak-to-valley). In other examples, a stent 10 may include some portions or segments with rings 18 arranged peak-to-peak, other portions or segments with the rings 18 arranged peak-to-valley, still other portions or segments with rings 18 having peaks and valleys that are circumferentially offset from both peaks and valleys of an immediately adjacent ring (e.g., no circumferential alignment), or any combination thereof.

[0082] In some examples, the stent 10 is a covered stent. For example, all or a portion of the stent 10 can be covered by a cover 42. An exemplary covered stent 10, including features of the present disclosure, is shown in a compressed configuration in FIG. 1C. As shown in FIG. 1C, the cover 42 encloses the entire flexible portion 12 of the stent 10. In some examples, a cover 42 can cover both the flexible portion 12 and rigid portion 14 (if present) of the stent 10. In other examples, only some sections or portions of the stent 10 may be covered while other sections or portions of the stent 10 are bare. For example, only the rigid portion 14 of the stent 10 may be covered by the cover 42 while the flexible portion 12 is bare, or vice versa. In other examples, the cover 42 may partially enclose both the flexible portion 12 and the rigid portion 14 of the stent 10, while segments or portions near the ends 2, 4 of the stent 10 are bare. The cover 42 can be formed from, for example, a sheet or film of a biocompatible material. The sheet or film can be configured to protect vessel walls defining the body passageway or vessel from edges of the rings 18 and other elements of the stent 10. In some examples, the cover 42 can be formed from a low friction material configured to protect the stent 10 and to reduce or prevent biological materials from adhering to portions of the stent 10. For example, the cover 42 can be formed from a low friction and/or hydroscopic material, such as expandable Polytetrafluoroethylene (ePTFE). In some examples, the material of the cover 42 is elastic and capable of stretching without breaking as the stent 10 expands. However, the elasticity of the material of the cover 42 should not be so strong as to cause the stent 10 to collapse from the expanded state back to the compressed state. In some examples, the cover 42 can be designed to perform a secondary function, such as to provide hemostasis. Also, the cover 42, the rings 18, and/or the elongated connectors 16 of the stent 10 can be coated, covered, and/or impregnated with a therapeutic agent, such as heparin.

[0083] The decision of whether the rings 18 are peak-to-peak, peak-to-valley, or offset is often based on whether the stent 10 is covered or bare, and, if covered, based on material characteristics of the cover 42. In particular, the stents 10 with the rings 18 arranged peak-to- valley can cause the cover 42 to stretch as the rings 18 expand and rotate or twist, because the peaks 24 of one ring 18 tend to rotate away from the valleys 26 of the immediately adjacent ring(s) 18 as the stent 10 expands. If the stent 10 is bare or if the cover material is flexible or elastic, then this movement of the peaks 24 and the valleys 26 may be acceptable. However, for the stents 10 comprising the cover 42 formed from a stiff material that does not stretch easily, rotation of the peaks 24 away from the valleys 26 could cause the cover 42 to tear. In such cases, using rings 18 arranged in a peak-to-peak configuration or an offset configuration may extend the usable life of the stent 10.

[0084] The flexible portions 12 and rigid portions 14 of the stent 10 further comprise the elongated struts or connectors 16 extending between the rings 18. As shown in FIG. IB, the elongated connectors 16 can comprise a proximal or first end 28 connected to one of the rings 18 at a connection point and a second end 30 connected to an immediately adjacent ring 18 at another connection point. The elongated connectors 16 can include one or more straight segments, such as a straight segment 32. In some examples, the elongated connectors 16 can also include bent portions, curved portions, pigtailed portions, or combinations thereof, configured to bend or unfold as the stent 10 transitions between the compressed state and the expanded state. For example, as shown in FIG. IB, elongated connectors 16 can include bent portions 34 near the ends 28, 30 of the elongated connector 16. The straight segment 32 is disposed between the bent portions 34 of the elongated connector 16. As illustrated in FIG. IB of the stent 10, there can be different shapes of the elongated connectors 16. In a first type of the elongated connectors 16, the bent portions 34 may extend from the ends of the straight segment 32 in the same direction, forming a substantial C-shape or reverse C-shape. In a second type of the elongated connectors 16, the bent portions 34 may extend from the ends of the straight segment 32 in opposite directions, forming a substantial S-shape or reverse S-shape. Also, while not shown in FIG. IB, some or all of the elongated connectors 16 can be branched, connecting to a particular ring 18 at two or more distinct connection points. Elongated connectors 16 of the flexible portion(s) 12 or rigid portion(s) 14 of the stent 10 can be generally identical or can have different shapes or widths to impart different structural characteristics for the stent 10. For example, narrower elongated connectors 16 (e.g., connectors 16 with a smaller width) may be used in regions of the stent 10 intended to be more flexible. Wider elongated connectors 16 can be used in regions of the stent 10 intended to be more rigid. In some examples, the width of the elongated connectors 16 extending between a ring 18 and an immediately adjacent ring 18 can be different. For example, the elongated connectors 16 at a 0 degree position and a 180 degree position circumferentially around the ring 18 may be wider, while the elongated connectors 16 at a 90 degree position and a 270 degree position of the ring 18 are narrower, which results in the stent 10 being less rigid at the 90 degree and 270 degree positions than at the 0 degree and 180 degree positions.

[0085] In some examples, the ends 28, 30 of the elongated connectors 16 are connected to linear segments 22 of the rings 18 near a middle point of the linear segments 22 (e.g., approximately an equal distance between the peak 24 and the adjacent valley 26 of the ring 18). In other examples, elongated connectors 16 can be connected to the rings 18 closer to the peaks 24 or valleys 26 of the ring 18. For example, as shown in FIGS. 11A-11D, the first end 28 of the elongated connector 16 can be connected near the peak 24 of a ring 18 and a second end 30 of the elongated connector 16 can be connected to an immediately adjacent ring 18, near the valley 26 of the immediately adjacent ring 18.

[0086] The number and position of the elongated connectors 16 generally influences the bending (i.e., flexural) stiffness of the stent 10 or stent segment and, in particular, influences in which directi on(s) the stent 10 or stent segment can bend with a reduced amount of force by decreasing the bending stiffness. That is, it will generally require less bending force to bend the stent 10 about a hinge axis H perpendicular to a gap axis G that passes through portions of the flexible portion 12 that do not include elongated connectors 16. That is, for a flexible portion 12 including first and second elongated connectors 16 located at 0 and 180 degrees, the flexible portion 12 will bend more easily about the axis H which extends along a diameter of the stent 10 so that the stent 10 deforms most along the axis G through the gaps between adjacent rings 18 at 90 (or 270) degrees offset from the hinge axis H. For example, as shown in the flexible portion 12 in FIG. IB, to provide a suitable bending stiffness permitting the stent 10 to bend in a predetermined direction upon application of a reduced amount of force, the elongated connectors 16 extending between a particular ring 18 and an immediately adjacent ring 18 can be spaced apart by about 180 degrees about a circumference of the stent 10. However, it is understood that for stents 10 including pairs of connectors 16 that form a hinge point, the elongated connectors 16 may not be spaced apart by exactly 180 degrees because the hinge point is between the elongated connectors 16 of a particular pair of the elongated connectors 16. In addition, as would be understood by those skilled in the art, where adjacent tubular sections of the stent 10 are connected by only two connectors 16, a hinge axis may be formed through the two connectors 16 even if they are not diametrically opposed. This will result in a larger gap on one side of the pair of connectors 16 and a smaller gap on the opposite side of the connectors 16 creating a preferential bending direction in which the stent 10 bends more easily about this hinge axis when the larger gap is located at an inner diameter of the bent stent 10 than when the smaller gap is located at this inner diameter.

[0087] In some examples, the substantially straight segment 32, for each elongated connector 16 extending from a particular ring 18 to an immediately adjacent ring 18, is axially and circumferentially offset from any other elongated connectors 16 extending from the particular ring 18. The rigid portions 14 of the stent 10 comprise the elongated connectors 16 arranged like the elongated connectors of the previously described conventional stents. For example, the rigid portions 14 of the stent 10 can include multiple elongated connectors 16 extending between a particular ring 18 and an immediately adjacent ring 18. The multiple elongated connectors 16 can be equidistantly spaced around a circumference of the stent 10 (e.g., spaced apart by 90 degrees) (i.e., equally spaced circumferentially with regard to immediately adjacent elongated connectors 16). The elongated connectors 16 of the rigid portion(s) 14 of the stent 10 can be axially and circumferentially offset, as shown in FIG. IB, or axially aligned to impart additional rigidity.

[0088] A detailed view of an exemplary flexible portion 12 of an expandable stent 10 is shown in FIGS. 2A (in a top view, two-dimensional configuration) and 3 (in a side view, three- dimensional configuration). The flexible portion 12 of the stent 10 in FIG. 2A comprises elongated connectors 16a, 16b, 16c positioned on opposite sides of the stent 10 (e.g., separated by 180 degrees). While the elongated connectors 16a, 16b, 16c (extending between adjacent rings 18a and 18b, 18b and 18c, and 18c and 18d, respectively) of the flexible portion 12 are axially offset and slightly circumferentially offset from one another, the elongated connectors 16a, 16b, 16c are generally positioned on the same sides of the stent 10 along the entire axial length of the flexible portion 12. Specifically, as shown in FIG. 2A, the elongated connectors 16a, 16b, 16c (extending between each of the rings 18a and 18b, 18b and 18c, and 18c and 18d, respectively) are positioned at or about at the 0 degree and 180 degree positions on each ring 18a, 18b, 18c, 18d.

[0089] As used herein, a “position” on a ring 18a, 18b, 18c, 18d refers to an arcuate distance around the ring 18a, 18b, 18c, 18d measured from an initial or 0 degree position around the ring to a final position of just less than 360 degrees (shown in FIG. 20). For convenience, the “position” or arcuate distance is described herein as being measured in degrees. The “position” or arcuate distance could also be measured or described in terms of a position on a face of a clock (e.g., 12 o’clock, 3 o’clock, 6 o’clock, etc.) or in terms of a number of linear segments 22 of the ring 18 separating the first elongated connector 16a from the second elongated connector 16b. For example, in FIG. 2A, one of the first elongated connectors 16a is separated from another one of the first elongated connectors 16a by a ring length comprising eight linear segments 22. The ring length is the shortest distance along a ring between potential connection points such as from the middle of a first one of the straight segments 32 to a second, adjacent one of the straight segments 32. The ring length is represented as line Rl.

[0090] As illustrated in FIG. 2A, there are no elongated connectors at the 90 degree and 270 degree positions, such that the flexible portion 12 includes regions or quadrants, shown by shapes S2a, S2b that are entirely free from elongated connectors. The configuration of the elongated connectors 16a, 16b, 16c of the flexible portion 12 allows for the stent 10 to hinge or bend more easily (in the flexible portion 12) at the 90 degree and 270 degree directions while maintaining more bending stiffness at the 0 degree and 180 degree directions. Specifically, the flexible portion 12 allows the stent 10 to hinge or bend with a reduced amount of force in the 90 degree and 270 degree directions while requiring an increased amount of force in the 0 degree and 180 degree directions. In one manner, a hinging axis is created through placement of the elongated connectors 16a, 16b, 16c at the 0 degree and 180 degree positions. Thus, the stent 10 may hinge or bend with less force about the hinging axis relative to hinging or bending other than about a hinging axis. The portions of the rings 18a, 18b, 18c, 18d, in regions (shown by shapes S2a, S2b) that are free from elongated connectors 16a, 16b, 16c have greater freedom of movement compared to other regions of the stent 10, meaning that such portions of the rings 18a, 18b, 18c, 18d can move towards or away from each other, which contributes to the enhanced hinging ability of the flexible portion 12 compared to conventional stent designs. Bending of the flexible portion 12 of the stent 10 is shown in FIG. 3, which shows that the elongated connectors 16a, 16b (particularly the elongated connectors 16c in FIG. 3) are configured to bend or flex to form the hinging axis. In this particular scenario shown in FIG. 3, the hinging axis may be a line extending through the elongated connectors 16c and perpendicular to a plane of the image. Thus, the elongated connector 16c is positioned at the 0 degree and 180 degree positions (e.g., the front and back of the illustration of the stent 10) and configured to bend with a reduced amount of force in the 90 degree and 270 degree directions (e.g., towards the top and bottom of the page of the image). However, the positioning of the elongated connectors 16a, 16b, 16c in FIG. 2A is not intended to be limiting. Instead, as shown by the exemplary flexible portions 12 illustrated in other figures, the elongated connectors 16 forming the flexible portions 12 of the stent 10 can be arranged in a wide variety of configurations to obtain desired amounts and directions of stent flexibility in order to adapt the stent 10 for different uses and deployment locations. Further, positioning and configuration of the elongated connectors 16a, 16b, 16c can vary along a length of the stent 10 (e.g., circumferentially offset along an axial direction), thereby providing a stent 10 with the multi -directional hinging mechanism previously described.

[0091] As shown in FIGS. 2A and 3, the flexible portion 12 includes a repeating pattern of radially expandable rings, which, for convenience, are identified herein as a first ring 18a, a second ring 18b, a third ring 18c, and a fourth ring 18d. The first ring 18a, second ring 18b, third ring 18c, and fourth ring 18d are aligned in series along the common axis XI of the stent 10. Those skilled in the art will understand that the term axis refers to the path connecting the centers of the rings 18 forming the stent 10 even when the stent 10 is curved along its length so that this ‘axis’ is not always a straight line. The number of rings 18a, 18b, 18c, 18d is not intended to be limiting for the present disclosure. Instead, in some examples, the stent 10 can include a repeating pattern of fewer than or more than four rings. For example, a stent 10 could include a repeating pattern of two or three rings. In some examples, each ring of the stent 10 may be different from any other ring. In other examples, all rings of the stent 10 may be identical.

[0092] In the example shown in FIGS. 2A and 3, the elongated connectors 16a, 16b, 16c shown in FIGS. 2A and 3 are not identical in shape. Instead, some of the elongated connectors (identified by reference numbers 16a, 16c in FIG. 2A) are symmetrical about a vertical axis including bent portions 34 that extend from linear segments 22 of the rings 18a, 18b in the same direction. Specifically, as shown in FIG. 2A, the elongated connector 16a extending between the first ring 18a and the second ring 18b extends from linear segments 22 of the rings 18a, 18b in an upward direction (shown by arrow Al in FIG. 2A). As shown in FIG. 2A, the elongated connector 16a extends between axially aligned linear segments 22 of the first ring 18a and the second ring 18b.

[0093] By contrast, the elongated connectors 16b extending between the second ring 18b and the third ring 18c are not symmetrical about a vertical axis. Instead, the first end 28 of the elongated connector 16b extends from the linear segment 22 of the first ring 18a in an upward direction (shown by arrow Al) and the second end 30 of the elongated connector 16b extends from the linear segment 22 of the third ring 18c in a downward direction (shown by arrow A2). The elongated connectors 16b are not connected between axially aligned linear segments of the rings 18b, 18c, as was the case for the elongated connectors 16a, 16c. Instead, the linear segment 22 of the second ring 18b (to which the elongated connector 16b is connected) is circumferentially offset from the linear segment 22 of the third ring 18c (to which the elongated connector 16b is connected) by one linear segment 22.

[0094] FIG. 4A is a detailed view of another exemplary flexible portion 12 of a stent 10 including the elongated connectors 16a, 16b, 16c positioned to produce a multi -directional hinging mechanism. As in previous examples, the flexible portion 12 comprises two symmetrical elongated connectors 16a extending between a first ring 18a and a second ring 18b, two non-symmetrical elongated connectors 16b extending between the second ring 18b and a third ring 18c, and two symmetrical elongated connectors 16c extending between the third ring 18c and a fourth ring 18d. The flexible portion 12 can include multiple groups of four rings 18a, 18b, 18c, 18d connected together in series producing a stent 10 with an elongated flexible region. As in previous examples, the elongated connectors 16a, 16b, 16c (extending between each of the rings 18a and 18b, 18b and 18c, and 18c and 18d, respectively) are positioned on opposite sides of the respective rings 18a, 18b, 18c, 18d separated by about 180 degrees. So that the same repeating pattern is present along a length of the flexible portion 12, the flexible portion 12 can instead include multiple groups of three rings 18a, 18b, 18c connected together in series due to the positioning of the elongated connectors 16a, 16b, 16c, as will become more apparent below. [0095] In the example of a stent 10 of the present disclosure as shown in FIG. 4A, the stent 10 differs from previous examples because the elongated connectors 16a, 16b, 16c (extending between the rings 18a and 18b, 18b and 18c, 18c and 18d, respectively) are not bunched as closely together as in previous examples. That is, the elongated connectors 16a, 16b, 16c are not as circumferentially aligned when viewed axially. Instead, in contrast to the elongated connectors 16a, 16b, 16c of the stent 10 shown in FIGS. 2A and 3 which are circumferentially offset when viewed axially by a trivial amount, the elongated connectors 16a, 16b, 16c in the exemplary stent 10 of FIG. 4A are circumferentially offset from each other when viewed axially by a non-trivial amount (e.g., from about 45 degrees to about 70 degrees). Thus, the elongated connectors 16a, 16b, 16c in the stent 10 of FIG. 4A are circumferentially offset moving axially along the length of the stent 10. In a specific exemplary embodiment, the stent 10 of FIG. 4A may include the elongated connectors 16a at the 0 and 180 degree positions, the elongated connectors 16b at the 90 and 270 degree positions, and the elongated connectors 16c at the 0 and 180 degree positions. In this manner, the elongated connectors 16a, 16b, 16c may be circumferentially and axially offset. This configuration of elongated connectors 16a, 16b, 16c (shown in FIG. 4A) allows for the flexible portion 12 of the stent 10 to hinge preferentially (e.g., with a reduced amount of force) at different hinge points depending on the direction that the stent 10 is bending. As discussed above in regard to FIG. 3, the stent 10 may create a hinging axis as a line extending through the elongated connectors 16 that are circumferentially offset from one another by 180 degrees. Through this hinging axis, the stent 10 may be configured to bend or hinge with a reduced amount of force about the hinging axis. Accordingly, for the elongated connectors 16a, 16c as shown in FIGS. 2A and 3 as well as in FIG. 4A, the stent 10 may bend or hinge with the reduced amount of force in the 90 and 270 degree directions. The stent 10 in FIG. 4A will also bend more easily when stressed in the general direction of 0 degrees and 180 degrees through the introduction of the elongated connectors 16b being positioned at the 90 and 270 degree positions. Thus, in the previous examples (such as in FIGS. 2A and 3), the stent 10 bends more easily in only two directions (e.g., in the 90 degree and 270 degree directions) and maintains greater bending stiffness in the other directions (e.g., in the 0 degree and 180 degree directions) along the entire length of the flexible portion 12 of the stent 10, because the elongated connectors 16a, 16b, 16c are all at or about at the 0 and 180 degree positions. The stent 10 of FIG. 4A may bend more easily in four directions (e.g., in the 0, 90, 180, and 270 degree directions) depending on whether the elongated connectors 16a, 16c create the hinging axis or whether the elongated connectors 16b create the hinging axis.

[0096] More precisely and to illustrate yet another exemplary embodiment of positioning the elongated connectors 16a, 16b, 16c to strategically reduce the amount of force to bend or hinge the stent 10, the flexible portion 12 of the stent 10 in FIG. 4A comprises the first ring 18a, the second ring 18b, the third ring 18c, and the fourth ring 18d. The rings 18a, 18b, 18c, 18d are arranged in series along the common axis XI of the stent 10. The elongated connectors 16a extending between the first ring 18a and the second ring 18b are separated by a ring length comprising eight linear segments 22 of the rings 18a, 18b or by about 180 degrees and located at the 0 and 180 degree positions. In a similar manner, the elongated connectors 16b extending between the second ring 18b and the third ring 18c are separated by a ring length comprising eight linear segments 22 or by about 180 degrees and located near the 90 and 270 degree positions. As shown by the shape S4a in FIG. 4A, the elongated connectors 16a are circumferentially offset or spaced apart from the elongated connectors 16b along the second ring 18b by a ring length comprising three linear segments 22 or about 45 degrees. As shown by shape S4b in FIG. 4 A, the elongated connectors 16c are circumferentially offset from the elongated connectors 16b by a ring length comprising four linear segments 22 or about 67.5 degrees along the third ring 18c.

[0097] FIG. 5 shows another example of the present disclosure of a flexible portion 12 of a stent 10 comprising the elongated connectors 16 arranged to form a multi -directional hinging mechanism. The elongated connectors 16 of the flexible portion 12 in FIG. 5 are arranged to form two spirals extending axially along a length of the flexible portion 12 of the stent 10, as shown by lines L2, L3 in FIG. 5. More specifically, as shown in FIG. 5, the flexible portion 12 of the stent 10 comprises the multiple expandable rings 18 aligned in series along the common axis XI of the stent 10. The rings 18 comprise the multiple linear segments 22 connected together end-to-end forming peaks 24 and valleys 26 of the rings 18. Each ring 18 in FIG. 5 includes eight peaks 24 and eight valleys 26. The rings 18 are arranged in a peak-to-valley configuration. However, it is understood that the spiral configuration is not meant to be limiting for the present disclosure. In other examples, the elongated connectors 16 between the rings 18 can be positioned at any of the eight or more connection points between a ring 18 and an immediately adjacent ring 18.

[0098] The flexible portion 12 in FIG. 5 further comprises the two elongated connectors 16 extending between each ring 18 and the immediately adjacent ring 18. As in previous examples, the elongated connectors 16 between each ring 18 and the immediately adjacent ring 18 are on opposite sides of the stent 10 separated by about 180 degrees. Further, in the example of the stent 10 shown in FIG. 5, the elongated connectors 16 are all symmetrical elongated connectors 16 that are identical in shape and extend from linear segments 22 of the rings 18 in an upward direction. There are eight different positions where the pair of elongated connectors 16 between a ring 18 and an immediately adjacent ring 18 could be positioned as shown by Positions 1-8 illustrated in FIG. 5. Stents 10 with fewer peaks 24 and valleys 26 per ring 18 element will have fewer potential hinge connection locations. The stents 10 including rings 18 with more than eight peaks 24 and eight valleys 26 will have more potential hinge connection locations. The elongated connectors 16 shown in FIG. 5 exhibit a generally C-shape. However, as described above, this shape is only for illustrative purposes and the exemplary embodiments may utilize different shapes. For example, as shown in FIG. IB, the elongated connectors 16 may also exhibit a reverse S-shape. In another example, the elongated connectors 16 may further exhibit a symmetrical shape such as an S-shape and/or a reverse C-shape. In a further example, stent 10 may include one or more of any of these shapes for the elongated connectors 16 (e.g., the stent 10 shown in FIG. IB includes elongated connectors 16 exhibiting a C-shape and a reverse S- shape).

[0099] As previously discussed, the elongated connectors 16 in FIG. 5 are arranged to form the two spirals (lines L2, L3) extending along the circumference and length of the flexible portion 12. In order to provide the spiral configuration, as shown in FIG. 5, the elongated connectors 16 extending from any one of the rings 18 in a proximal direction (e.g., towards a proximal end 2 of the stent 10) are circumferentially offset from the elongated connectors 16 extending from that particular ring 18 in a distal direction (e.g., towards the distal end 4 of the stent 10) by a ring length comprising one linear segment 22, such that each hinge or connector position appears to move up one step from the previous hinge position. Therefore, as shown in FIG. 5, in the spiral configuration, a connection point (shown by reference number 36 in FIG. 5) for an elongated connector 16 extending from a particular ring 18 is circumferentially offset from the other connection point 36 on the adjacent linear segment 22 of that particular ring 18. For example, as shown in FIG. 5, the line L4 extending through a connection point 36 on the ring 18 is circumferentially offset from (e.g., does not intersect or overlap with) a line L5 extending through an adjacent connection point 36 on that same ring 18.

[00100] FIG. 6 is another example of a flexible portion 12 of a stent 10 of the present disclosure. The flexible portion 12 in FIG. 6 comprises elongated connectors 16d, 16e positioned on one side of the stent 10 forming a clustered backbone of elongated connectors 16d, 16e extending axially through the flexible portion 12. Other areas of the stent 10 shown by shapes S6a in FIG. 6 are free from elongated connectors 16d, 16e. This design allows the flexible portion 12 of the stent 10 to freely hinge in one direction (e.g., away from the cluster of the elongated connectors 16) and bend to accommodate sharp comers without kinking.

[00101] As shown in FIG. 6, the flexible portion 12 comprises the multiple expandable rings 18a, 18b, 18c, 18d aligned in series along the common axis XI. For illustrative purposes, the stent 10 shown in FIG. 6 also includes further expandable rings 18e, 18f The rings 18a, 18b, 18c, 18d, 18e, 18f comprise the multiple linear segments 22 (e.g., 16 total linear segments 22 for each of the rings 18a-f) connected together end-to-end forming peaks 24 and valleys 26 of the rings 18a, 18b, 18c, 18d. The rings 18a, 18b, 18c, 18d in FIG. 6 are arranged in a peak-to-valley configuration. The flexible portion 12 also includes the elongated connectors 16d, 16e extending between each ring 18a, 18b, 18c, 18d, 18e and an immediately distally adjacent ring 18b, 18c, 18d, 18e, 18f, respectively. Unlike in previous examples where the elongated connectors 16a, 16b, 16c were positioned on opposite sides of the rings 18 or 180 degrees circumferentially apart within a given ring 18 (e.g., as shown in the stent 10 of FIGS. 2A, 3, 4A, and 5), the elongated connectors 16d, 16e extending between each ring 18a, 18b, 18c, 18d, 18e and the immediately distally adjacent ring 18b, 18c, 18d, 18e, 18f, respectively, in FIG. 6 are separated by only a ring length comprising three linear segments 22 (e.g., about 45 degrees) in a first direction. The elongated connectors 16d, 16e in FIG. 6 are separated by a ring length comprising thirteen linear segments 22 or about 315 degrees in a second direction. The other areas or regions of the rings 18a, 18b, 18c, 18d shown by shapes S6a in FIG. 6 are free from elongated connectors 16d, 16e. By contrast, in previous examples (as shown in FIGS. 2A, 3, 4A, and 5), the two elongated connectors 16a, 16b, 16c extending between each ring 18a, 18b, 18c, 18d and an immediately adjacent ring 18a, 18b, 18c, 18d were on opposite sides of the rings 18a, 18b, 18c, 18d separated by about 180 degrees in both directions. In the example of the stent 10 shown in FIG. 6, portions of the rings 18a, 18b, 18c, 18d, 18e, 18f in regions (shown by shapes S6a) that are free from the elongated connectors 16d, 16e have greater freedom of movement compared to other regions of the stent 10, meaning that such portions of the rings 18a, 18b, 18c, 18d can move towards or away from each other more freely, which contributes to the enhanced hinging ability of the flexible portion 12 compared to conventional stent designs. In this manner, the stent 10 shown in FIG. 6 with the configuration of the elongated connectors 16d, 16e may enable a variable hinging direction in which the location of the elongated connectors 16d, 16e may provide a pivot point with a range of motion (e g., accommodating hinging in multiple dimensions in multiple planes) that requires a reduced amount of force rather than a hinging axis when the elongated connectors 16 are separated by 180 degrees (e.g., accommodating hinging in two primary and opposite directions, the directions being co-planar).

[00102] As shown in FIG. 6, there are four elongated connectors 16d, 16e extending from, for example, the second ring 18b. Two of the elongated connectors 16d, 16e extend in a proximal direction (i.e., towards the proximal end 2 of the stent 10) to the first ring 18a. Two of the elongated connectors 16d, 16e extend in the distal direction (i.e., towards the distal end 4 of the stent 10) to a third ring 18c. Also, two of the elongated connectors 16d, 16e are connected to the same linear segment 22 of the second ring 18b. In the example shown in FIG. 6, the elongated connectors 16d, 16e are all symmetrical, but they are not identical in shape (although they could be identical in other examples of the stent 10 of the present disclosure). Instead, the elongated connectors 16d extend from the linear segments 22 of the rings 18a, 18b, 18c, 18d in an upward direction (shown by arrow Al in FIG. 6), and the elongated connectors 16e extend from the linear segments 22 of the rings 18a, 18b, 18c, 18d in a downward direction (shown by arrow A2 in FIG. 6).

[00103] FIG. 7 shows another non-limiting example of a flexible portion 12 of a stent 10 in accordance with the present disclosure. Similar to FIG. 6, the flexible portion 12 in FIG. 7 includes a clustered arrangement of elongated connectors 16d, 16e. In the configuration of FIG. 7, the stent 10 freely hinges in multiple directions and can make sharp corners without kinking in a manner substantially similar to the stent 10 of FIG. 6. As in previous examples, the elongated connectors 16d, 16e can be arranged in any number of positions to obtain a desired flexibility for the flexible portion 12 of the stent 10. The elongated connectors 16d, 16e shown in the example of FIG. 7 are all symmetrical, but are not identical. Instead, the elongated connectors 16d include bent portions 34 extending from linear segments 22 of the rings 18a, 18b, 18c, 18d in an upward direction (shown by arrow Al in FIG. 7), and the elongated connectors 16e include bent portions 34 extending from the linear segments 22 of the rings 18a, 18b, 18c, 18d in a downward direction (shown by arrow A2 in FIG. 7).

[00104] As shown in FIG. 7, the flexible portion 12 comprises the multiple expandable rings 18a, 18b, 18c, 18d, 18e, 18f arranged in series along the common axis XI. The rings 18a, 18b, 18c, 18d, 18e, 18f are arranged in a peak-to-valley configuration. As in previous examples, there are two elongated connectors 16d, 16e extending between a ring, such as the first ring 18a, and an immediately adjacent ring, such as a second ring 18b. Also, as in FIG. 6, the two elongated connectors 16d, 16e are separated by a ring length comprising three linear segments 22 of the ring 18a, which is about 45 degrees. Other areas of the rings 18a, 18b, 18c, 18d, 18e, 18f shown by shapes S7a and S7b in FIG. 7 are free from the elongated connectors 16d, 16e. As a result, the regions shown by shapes S7a, S7b have greater freedom of movement compared to other regions of the stent 10, meaning that such portions of the rings 18a, 18b, 18c, 18d can move towards or away from each other more freely, which contributes to the enhanced hinging ability of the flexible portion 12 compared to conventional stent designs.

[00105] Unlike in FIG. 6, the elongated connectors 16d, 16e of the flexible portion 12 in FIG. 7 are not all positioned on only one side of the stent 10 forming the clustered backbone. Instead, in FIG. 7, the elongated connectors 16d, 16e extending between the first ring 18a and the second ring 18b are on an opposite side of the stent 10 from the elongated connectors 16d, 16e extending between the second ring 18b and the third ring 18c. As shown, for each adjacent pair of the rings 18 where there is a common ring 18 (e g., a first pair being ring 18a and 18b with a second pair being ring 18b and 18c), the elongated connectors 16d, 16e extending between the first pair of the rings 18 is circumferentially and axially offset from the elongated connectors 16d, 16e between the second pair of the rings 18. Accordingly, the elongated connectors 16d, 16e extending from the ring 18b in one direction (e g., towards the proximal end 2 of the stent 10) are separated by a ring length comprising six linear segments 22 of the ring 18b (about 112.5 degrees) from the elongated connectors 16d, 16e extending in the other direction (towards the distal end 4 of the stent 10). As in previous examples, the pattern of spaced-apart elongated connectors 16 can continue along an entire length of the flexible portion 12 of the stent 10.

[00106] FIG. 8A shows another exemplary flexible portion 12 of a stent 10 of the present disclosure comprising the multiple expandable rings 18a, 18b, 18c, 18d, 18e, 18f aligned in series along the common axis XI. The flexible portion 12 in FIG. 8A comprises four elongated connectors 16f, 16g extending between each ring 18a, 18b, 18c, 18d, 18e and an immediately distally adjacent ring 18b, 18c, 18d, 18e, 18f, respectively, of the flexible portion 12. The elongated connectors 16f, 16g are arranged in pairs. The elongated connectors 16f, 16g of a “pair” are connected to immediately adjacent linear segments 22 of the rings 18a, 18b, 18c, 18d, 18e, 18f. Specifically, there is a first pair comprising two of the elongated connectors 16f connected to adjacent linear segments 22 and a second pair comprising two of the elongated connectors 16g connected to a second set of adjacent linear segments 22 of the rings 18a, 18b, 18c, 18d, 18e, 18f The first and second pairs of the elongated connectors 16f, 16g are circumferentially offset within a given pair of the rings 18a-f. This design allows the flexible portion 12 of the stent 10 to freely hinge in multiple directions and make sharp corners without kinking.

[00107] As shown in FIG. 8 A, the first pair of connectors 16f and the second pair of connectors 16g are positioned on opposite sides of the rings 18a, 18b, 18c, 18d, 18e, 18f, such that the pairs are separated by a ring length comprising seven linear segments 22 of the rings 18a, 18b, 18c, 18d, 18e, 18f or about 135 degrees. As in previous examples, the elongated connectors 16f, 16g include bent portions 34. Further, some of the elongated connectors 16f, 16g bend in an upwards direction (shown by arrow Al in FIG. 8A) and other elongated connectors 16f, 16g bend in a downward direction (shown by arrow A2 in FIG. 8A). An elongated connector 16f is on a linear segment 22 that is adjacent to a linear segment 22 for its paired elongated connector 16f, such that paired ones of the elongated connectors 16f are separated by less than about 25 degrees in a first direction. The elongated connectors 16f are separated from an immediately adjacent elongated connector 16g of the other pair (connecting the same two rings) by a ring length comprising seven linear segments 22 (about 135 degrees in a second direction). Each pair of connectors 16c, 16d includes a symmetrical upward facing connector and a symmetrical downward facing connector. The stent 10 also includes areas, shown by shapes S8a and S8b, that are free from elongated connectors 16c 16d, and as a result have greater freedom of movement compared to other regions of the stent 10, meaning that such portions of the rings 18a, 18b, 18c, 18d can move towards or away from each other more freely, which contributes to the enhanced hinging ability of the flexible portion 12 compared to conventional stent designs. In some examples the regions shown by the shapes S8a, S8b may not extend an entire length of the stent 10. Instead, some portions of the stent 10 can include the regions S8a, S8b, while other portions of the stent 10 include additional elongated connectors 16f, 16g and/or elongated connectors 16f, 16g at different positions about the circumference of the stent 10. Also, as in previous examples, the connectors 16f, 16g may also be arranged in any number of other positions around the rings 18a, 18b, 18c, 18d, 18e, 18f to achieve the desired flexibility for the stent. In another manner of viewing the paired elongated connectors 16f, 16g, the stent 10 of FIG. 8A may be substantially similar to the stent 10 described above with regard to FIGS. 2A, 3, 4 A, and 5. Specifically, the pairs of the elongated connectors 16f, 16g are circumferentially separated between two rings 18 by 180 degrees or positioned on opposite sides of the stent 10. In contrast to the stent 10 of FIGS. 2A, 3, 4A, and 5, the stent 10 of FIG. 8A pairs the elongated connectors. The pairs of the elongated connectors 16f, 16g may also create a corresponding hinging axis about which the stent 10 may bend or hinge with a reduced amount of force. [00108] FIG. 9 shows another exemplary flexible portion 12 of a stent 10 of the present disclosure comprising the multiple expandable rings 18a, 18b, 18c, 18d aligned in series along the common axis XI. As illustrated, the stent 10 may utilize a repeating pattern of the expandable rings 18a-d. Thus, a series of the rings 18a-d may repeat with a ring 18d from a proximal set (e.g., closer to the proximal end 2) being adjacent to a ring 18a from a distal set (e g., closer to the distal end 4). As in previous examples, the expandable rings 18a, 18b, 18c, 18d are formed from the linear segments 22 arranged end-to-end defining the peaks 24 and the valleys 26 of the rings 18a, 18b, 18c, 18d. The rings 18a, 18b, 18c, 18d in FIG. 9 are in a peak- to-peak configuration where peaks 24 of one ring are axially aligned with peaks 24 of the other rings.

[00109] As in FIG. 8 A with paired ones of the elongated connectors 16f, 16g, the flexible portion 12 in FIG. 9 comprises four elongated connectors 16h, 16i extending between each ring 18a, 18b, 18c, 18d and an immediately adjacent ring 18b, 18c, 18d, 18a, respectively, of the flexible portion 12. The elongated connectors 16h, 16i are arranged in pairs, namely the first pair comprising two of the elongated connectors 16h connected to adjacent linear segments 22 of a particular ring 18a, 18b, 18c, 18d and the second pair comprising two of the elongated connectors 16i connected to a second set of adjacent linear segments 22 of the particular ring 18a, 18b, 18c, 18d. As in FIG. 8A, this design allows the stent 10 to freely hinge in multiple directions and make sharp corners without kinking. In the exemplary embodiment shown in FIG. 9, the pairs of the elongated connectors 16h, 16i may be circumferentially offset between a given pair of the rings 18a-d by 180 degrees or positioned on opposite sides of the stent 10. In this manner, the elongated connectors 16h, 16i may create a hinging axis about which the stent 10 of FIG. 9 may bend or hinge. As in previous examples, the connectors 16h, 16i may also be arranged in any number of other positions around the rings 18a, 18b, 18c, 18d to achieve the desired flexibility for the stent.

[00110] As shown in FIG. 9, the pair of the elongated connectors 16h and the pair of the elongated connectors 16i are positioned on opposite sides of the rings 18a, 18b, 18c, 18d, such that the pairs connecting the same two rings are separated by a ring length comprising seven linear segments 22 of the rings 18a, 18b, 18c, 18d or about 135 degrees. That is, one of the elongated connectors 16h is separated to a closer one of the elongated connectors 16i by this ring length. However, when considering a distance by which a pair of the elongated connectors 16h is separated to a pair of the elongated connectors 16i, the pairs may be separated by 180 degrees or a ring length comprising eight linear segments 22. The elongated connectors 16h, 16i in FIG. 9 differ from previous examples because they include an angled segment 38, which accommodates the peak-to-peak configuration of the rings 18a, 18b, 18c, 18d. More specifically, the elongated connectors 16h, 16i in FIG. 9 include the bent portions 34 at the first end 28 and the second end 30 of the connectors 16h, 16i . The connectors 16h, 16i further comprise two straight segments 32 separated by the angled segment 38. Further, each pair of the elongated connectors 16h, 16i includes an upward facing connector (shown by arrow A2 in FIG. 9) and a downward facing connector (shown by arrow A2 in FIG. 9).

[00111] FIGS. 17-19 show additional examples of stents 10 including the elongated connectors 16h, 16i with angled segments 38 extending between the rings 18a, 18b, 18c, 18d. In a similar manner to the stent 10 of FIG. 9, the rings 18a-d may repeat as sets. While the elongated connectors 16h, 16i in FIGS. 17-19 are generally similar in shape to the connectors 16h, 16i in FIG. 9 including the angled segments 38, the stents 10 of FIGS. 17-19 differ from previous examples in positioning and orientation of the elongated connectors 16h, 16i. For example, as shown in FIG. 17, the stent 10 includes pairs of the elongated connectors 16h and pairs of the elongated connectors 16i extending between each ring 18a, 18b, 18c, 18d and an immediately distally adjacent ring 18b, 18c, 18d, 18a. However, the stent 10 of FIG. 17 differs from the stent 10 of FIG. 9 because, in FIG. 17, the pairs of the elongated connectors 16h, 16i on adjacent rings 18a, 18b, 18c, 18d are connected to adjacent linear segments 22. In particular, the connectors 16h extending between the first ring 18a and the second ring 18b are connected to an adjacent linear segment 22 to the connectors 16h extending between the second ring 18b and the third ring 18c. Other pairs of the elongated connectors 16h, 16i in FIG. 17 are positioned in a similar configuration. [00112] FIG. 18 shows another example of a stent 10 including the elongated connectors 16j, 16k including the angled segments 38. The elongated connectors 16j include bent portions 34 extending from a linear segment 22 in an upward direction (shown by arrow Al in FIG. 18). The elongated connectors 16k include bent portions 34 extending from a linear segment 22 in a downward direction (shown by arrow A2 in FIG. 18). The stent 10 of FIG. 18 differs from previous examples because, in FIG. 18, there are two of the elongated connectors 16j , 16k extending from a single linear segment 22. For example, as shown in FIG. 18, some of the elongated connectors 16k with upward bent portions 34 extending between the first ring 18a and the second ring 18b are connected to a same linear segment 22 of the second ring 18b as are the elongated connectors 16j with downward bent portions 34 extending between the second ring 18b and the third ring 18c. In a similar manner, some of the elongated connectors 16j with downward bent portions 34 extending between the first ring 18a and the second ring 18b are connected to a same linear segment 22 of the second ring 18b as are the elongated connectors 16k with upward bent portions 34 extending between the second ring 18b and the third ring 18c. This configuration of the elongated connectors 16j , 16k extending from a same linear segment 22 is continued throughout the stent 10 as shown in FIG. 18.

[00113] FIG. 19 shows another exemplary stent 10 including pairs of the elongated connectors 16h, 16i extending between a ring 18a, 18b, 18c, 18d and an immediately adjacent ring 18b, 18c, 18d, 18a. As in previous examples, the connectors 16h, 16i include the angled segment 38. The stent 10 of FIG. 19 differs from the stent 10 of FIG. 9 because, in FIG. 19, angled segments 38 for different connectors 16h, 16i are angled in different directions. For example, as shown in FIG. 19, a pair of the elongated connectors 16h and a pair of the elongated connectors 16i extend between the first ring 18a and the second ring 18b. These elongated connectors 16h, 16i between the first ring 18a and the second ring 18b are angled in an upward direction, as shown by arrow A3 in FIG. 19. There is also a pair of the elongated connectors 16h and a pair of the elongated connectors 16i extending between the second ring 18b and the third ring 18c. However, the elongated connectors 16h, 16i between the second ring 18b and the third ring 18c are angled in a downward direction, as shown by arrow A4 in FIG. 19. The arrangement of upwardly angled and downwardly angled ones of the elongated connectors 16h, 16i can continue between other rings 18b, 18c, 18d of the stent 10 as shown in FIG. 19.

Non-limiting examples of elongated connector configurations [00114] As previously described, the elongated connectors 16, 16a, 16b, 16c, 16d can be configured in a variety of shapes and configurations to achieve desired flexibility and expansion of the stent 10. FIGS. 10A-10D illustrate different variations of an elongated connector 16 used in some of the previously described flexible portions 12 of the stent 10. The elongated connectors 16 shown in FIGS. 10A-10D can also be used in rigid portions 14 of the stent 10, when present.

[00115] The elongated connector 16 in FIG. 10A is vertically symmetrical with the bent portion 34 at a first end 28 of the connector 16, another bent portion 34 at the second end 30 of the connector 16, and the substantially straight segment 32 extending between the first end 28 and the second end 30 of the connector 16. The bent portions 34 in FIG. 10A both extend from linear segments 22 of expandable rings 18a, 18b in the same direction (e.g., in an upward direction from the linear segments 22 shown by arrow Al in FIG. 10A). Further, the elongated connector 16 in FIG. 10A extends from the middle of the linear segments 22 of the rings 18a, 18b.

[00116] FIG. 10B shows an elongated connector 16 that is symmetrical and includes bent portions 34 at ends 28, 30 of the connector 16 that extend from linear segments 22 of the rings 18a, 18b in a downward direction, shown by arrow A2 in FIG. 10B.

[00117] FIGS. 10C and 10D show elongated connectors 16 that are non-symmetrical (e.g., not vertically symmetrical) and extending between expandable rings 18a, 18b. The elongated connectors 16 in FIGS. 10C and 10D comprise a bent portion 34 at the first end 28 of the connector 16, a bent portion 34 at the second end 30 of the connector 16, and the substantially straight segment 32 extending between the ends 28, 30 of the connector 16. In the example shown in FIG. 10C, the bent portion 34 at the first end 28 of the connector 16 extends from a linear segment 22 of a first expandable ring 18a in an upward direction (shown by arrow Al in FIG. 10C), and the bent portion 34 at the second end 30 of the connector 16 extends from a linear segment 22 of a second expandable ring 18b in a downward direction (shown by arrow A2 in FIG. 10C). The connection points 36a, 36b between the linear segments 22 of the rings 18a, 18b are not axially aligned. Instead, the connection point 36a between the first ring 18a and the connector 16 is circumferentially offset from the connection point 36b between the connector 16 and the second ring 18b by one linear segment 22. The elongated connector 16 in FIG. 10D is a mirror image of the elongated connector 16 of FIG. 10C. Specifically, as shown in FIG. 10D, the bent portion 34 at the first end 28 of the connector 16 extends from the linear segment 22 of the first ring 18a in a downward direction (shown by arrow A2 in FIG. 10D), and the bent portion 34 at the second end 30 of the connector 16 extends from the linear segment 22 of the second ring 18b in an upward direction (shown by arrow Al in FIG. 10D).

[00118] FIGS. 11A-11D show additional examples of elongated connectors 16 that can be used in the flexible portions 12 and/or rigid portions 14 of the stent 10 of the present disclosure. The elongated connectors 16 shown in FIGS. 11A-1 ID can be used as the elongated connectors 16 in any of the flexible portions 12 and rigid portions 14 of the stents 10 described herein. The elongated connectors 16 shown in FIGS. 11 A-l ID are extended length versions of the elongated connectors 16 extending from a point near to a peak 24 of one ring 18a to a point near to a valley 26 of the adjacent ring 18b.

[00119] Unlike in previous examples, the elongated connectors 16 in FIG. 11 A-l ID are not connected to, and do not extend from, the middle of the linear segments 22 of the rings 18a, 18b (e.g., a point that is substantially equidistant between peaks 24 and valleys 26) of the rings 18a, 18b. Instead, the elongated connectors 16 in FIGS. 11A-1 ID are connected to points of the linear segments 22 closer to either the peaks 24 or the valleys 26 of the rings 18a, 18b. For example, as shown in FIG. 11 A, rings 18a, 18b are arranged in a peak-to-valley configuration. The elongated connector 16 includes a bent portion 34 at a first end 28 of the connector 16, a bent portion 34 at a second end 30 of the connector 16, and a substantially straight segment 32 extending between the first end 28 and the second end 30. The bent portion 34 on the first end 28 extends from a linear segment 22 of the first ring 18a in an upward direction (shown by arrow Al in FIG. 11A) and is positioned near a peak 24 of the first ring 18a. The bent portion 34 at the second end 30 of the connector 16 extends in an upward direction (shown by arrow A2 in FIG. 11A) from a linear segment 22 of the second ring 18b and is positioned near a valley 26 of the second ring 18b. FIG. 1 IB shows a symmetrical elongated connector 16 similar to the connector of FIG. 11 A, but with bent portions 34 that extend from linear segments 22 in a downward direction (shown by arrow A2 in FIG. 1 IB).

[00120] FIGS. 11C and 1 ID show elongated connectors 16 that are non-symmetrical and extended in length compared to the elongated connectors that are non-symmetrical in FIGS. 10C and 10D. In FIG. 11C, a bent portion 34 at a first end 28 of the connector 16 extends from the linear segment 22 of a first ring 18a in an upward direction (shown by arrow Al in FIG. 11C). The first end 28 of the connector 16 connects to the linear segment 22 of the first ring 18a near to the peak 24 of the ring 18a. The bent portion 34 at a second end 30 of the connector 16 extends from the linear segment 22 of the second ring 18b in a downward direction (shown by arrow A2 in FIG. 11C). The second end 30 of the connector 16 connects to a linear segment 22 of the second ring 18b near to the valley 26 of the second ring 18b. FIG. 1 ID is a mirror image of FIG. 11C, in which the bent portion 34 at the first end 28 of the elongated connector 16 extends in a downward direction (arrow A2 in FIG. 1 ID) from the linear segment 22 of the first ring 18a, and the bent portion 34 of the elongated connector 16 at the second end 30 of the connector 16 extends from the linear segment 22 of the second ring 18b in an upward direction (arrow Al in FIG. 11D).

[00121] With reference to FIG. 12, in some examples, the flexible portion 12 or rigid portion 14 of the stent 10 comprise struts 40 extending between a valley 26 of a ring 18a and a peak 24 of an immediately adjacent ring 18b. Struts 40 may be used as an alternative or replacement for the elongated connectors 16, where the struts 40 are configured to hinge to allow the stent 10 to bend without kinking. In other examples, a stent 10 can include both the elongated connectors 16 and the struts 40 to provide a desired flexibility for the stent.

[00122] As shown in the example in FIG. 12, a flexible portion 12 and/or rigid portion 14 of a stent 10 comprises a first ring 18a and a second ring 18b in a peak-to-valley configuration. The strut 40 is connected to and extends axially from the valley 26 of the first ring 18a to the peak 24 of the second ring 18b. In some examples, while not shown in FIG. 12, the flexible portion 12 can include two struts 40 between each of the rings 18a, 18b. The two struts 40 can be on opposite sides of the stent 10 separated by about 180 degrees, in a similar configuration to the elongated connectors 16 in the previously described examples. When used with the flexible portion 12, the strut 40 provides a location for the stent 10 to bend without kinking, and may also provide added rigidity (e.g., column strength) and support to selected regions of the flexible portion 12. The rigid portion 14 of the stent 10 can also include struts 40 instead of or in addition to the previously described elongated connectors 16 to enhance rigidity of the rigid portion 14. For example, similar to the rigid portion 14 in FIG. 1C, a rigid portion 14 can include four struts 40 between each expandable ring 18a, 18b, with the struts 40 equidistantly spaced around the ring 18 separated by about 90 degrees. In other examples, a rigid portion 14 can include more than four struts 40 between each expandable ring 18a, 18b, or less than four struts 40 between each expandable ring 18a, 18b.

Non-limiting examples of flexible portions with directly connected rings

[00123] With reference to FIG. 13, in some examples, the flexible portion 12 or the rigid portion 14 of the stent 10 comprises rings, such as a first ring 18a and a second ring 18b, which are directly connected together without elongated connectors or struts. Instead, valleys 26 of the first ring 18a can be directly connected to and/or integrally formed with peaks 24 of the immediately adjacent second ring 18b.

[00124] For example, as shown in FIG. 13, an expandable stent 10 configured to radially expand from a retracted or compressed (e.g., crimped) configuration to an expanded configuration comprises a plurality of radially expandable rings, such as the first ring 18a and the second ring 18b, similar in size and configuration to previous examples. As in previous examples, the rings 18a, 18b comprise multiple linear segments 22 connected together end-to- end forming peaks 24 and valleys 26 of the ring 18a, 18b. The rings 18a, 18b in FIG. 13 are arranged in a peak-to-valley configuration. As shown in FIG. 13, one of the valleys 26 of the first ring 18a is directly connected to the peak 24 of the second ring 18b, thereby connecting the first ring 18a to the second ring 18b. In the example shown in FIG. 13, other valleys 26 of the first ring 18a are spaced apart from peaks 24 of the second ring 18b by a distance or gap Gl.

[00125] As in previous examples, the rings 18a, 18b may be connected together in a variety of configurations to provide desired flexibility and/or to allow the stent 10 to bend in various directions without kinking. For example, a flexible portion 12 of a stent 10 could include two connection points where each ring 18a directly connects to the second ring 18b. The connection points could be positioned, for example, on opposite sides of the rings 18a, 18b spaced apart by about 180 degrees. Peaks 24 and valleys 26 of other portions of the rings 18a, 18b can be separated by the gap Gl . In some examples, the connection points for directly connecting the rings 18a, 18b together can be on only one side of the stent 10 along the entire axial length of the stent 10, forming a clustered backbone, similar to the example shown in FIG. 6. In other examples, connection points between the rings 18a, 18b of the stent 10 can be positioned to create spirals extending axially along the flexible portion 12 of the stent 10 (as shown in FIG. 5), or in any other convenient configuration that provides bending or flexing at desired positions and directions along a length of the stent 10.

[00126] In some examples, rigid portions 14 of the stent 10, if present, can also include rings 18a, 18b that are integral or directly connected together. For example, a rigid portion 14 of a stent 10 could include a first ring 18a with valleys 26 directly connected to peaks 24 of a second ring 18b at four or more equidistantly spaced connection points. In other examples, a rigid portion 14 of a stent 10 could include a first ring 18a with valleys 26 directly connected to peaks 24 of a second ring 18b at less than four equidistantly spaced connection points. In one specific example, the rigid portion 14 could include four connection points between adjacent rings 18a, 18b separated by about 90 degrees, similar to the rigid portion 14 shown in FIG. 1C.

Non-limiting examples of deployment methods

[00127] With reference to FIG. 14, a method for deploying a stent 10 including features described herein is shown. The deployment method can be applicable to any of the stent 10 embodiments of this disclosure. As shown at step 110 of the method, a selected stent 10 is prepared for surgery by removing it from its packaging and removing a protective sheath that covers the stent 10 during storage. The stent 10 is initially provided in a compressed state, such as crimped on a balloon expandable catheter. As previously described, the stents 10 of the present disclosure are configured to bend or hinge easily in one or more directions based on positioning of the elongated connectors 16 and/or other connections between rings 18 of the stent 10. Stents 10 can be selected for particular surgical procedures and target deployment sites based on how the stent 10 is required to bend or hinge when deployed. For example, a stent 10 (as shown in FIG. 6) with elongated connectors 16 forming a clustered backbone extending axially through a flexible portion 12 of the stent 10 bends more easily without kinking in a range of directions away from the clustered backbone. A stent 10 with a clustered backbone of elongated connectors is able to bend around a sharp corner through bending in a direction within the range without kinking. A stent 10 that bends easily with a reduced amount of force and which can be bent around a sharp corner without kinking may be useful for surgical procedures in which the stent is positioned within a branched artery or where the stent 10 extends through an opening from one body passageway to another. Other uses for a stent that bends easily around sharp comers will also be easily determined by those skilled in the art. In other examples, the stent 10 is configured with a multi -directional hinging mechanism that bends easily in multiple selected directions (e g., through creating a hinging axis such as in FIG. 9). Multi -directional hinging stents 10 may be selected for use in deployment locations where the stent 10 is exposed to multiple different bending forces and/or is bent or twisted in multiple directions. Uses for stents that bend more easily in multiple directions, but which are not required to bend around sharp comers, will also be easily determined by those skilled in the art. Exemplary stents 10 configured to bend in multiple directions are shown in FIGS. 4A, 5, and 9.

[00128] At step 112 of the method, a delivery assembly comprising a catheter or sheath and a guidewire for advancing the stent 10 through vasculature or other lumen of a patient to a deployment location is provided. The deployment location can be any desired position within the vasculature or other lumen of the patient. For example, the stent 10 can be deployed in a vessel or artery. In some examples, the stent 10 is deployed within an endograft. As previously described, a stent with specific hinging and bending characteristics can be selected for a particular desired surgical procedure and deployment location.

[00129] The stent 10 is crimped to the balloon catheter and can be inserted in a delivery catheter. In order to deploy the stent 10, at step 114 of the method, the guidewire is introduced through the vasculature or other lumen to the desired deployment location. Once the guidewire is in place, at step 116 of the method, the delivery catheter, balloon catheter, and stent device mounted thereto are advanced to the deployment location over the guidewire.

[00130] At step 118 of the method, once the stent 10 is at the desired deployment location, the balloon catheter is expanded. Radial outward expansion of the expandable portion of the balloon catheter causes the expandable rings 18 of the stent 10 to expand outwardly, as described previously. Following expansion, the guidewire can be removed and the stent 10 can adopt a curved, bent, or hinged configuration, as required by the surgical procedure and deployment site.

Examples

[00131] The following non-limiting examples are presented to demonstrate general principles of embodiments in accordance with this disclosure. This disclosure, and any claimed embodiments, should not be considered as limited to the specific examples presented.

Prophetic Example 1

[00132] As previously described, the flexible portion 12 of the stent 10 shown in FIG. 2A includes pairs of the elongated connectors 16a, 16b, and 16c, which connect rings 18a and 18b, 18b and 18c, and 18c and 18d, respectively. As shown in FIG. 2A, each in the pair of the elongated connectors 16a, 16b, 16c are positioned on opposite sides of the stent 10, separated by about 180 degrees. When positioned at the 0 and 180 degree positions (e.g., the 0 degree position may be arbitrarily assigned about a circumference of the rings and the subsequent measurements may be based on this 0 degree position), the stent 10 is configured to hinge more easily with a reduced amount of force in the 90 degree and 270 degree directions while maintaining more bending stiffness in the 0 degree and 180 degree directions.

[00133] FIG. 2B is a graph showing forces that are required to bend the flexible portion 12 of the stent 10 shown in FIG. 2A and the flexible portion 12 of the stent 10 shown in FIG. 3 by a distance of 2.0 mm as calculated by finite element analysis (FEA). Bending of the stent 10 in FIG. 2A is compared to bending of a conventional stent (such as the iCAST/V12 stent sold by Atrium Medical Corporation) having four equidistantly spaced connectors extending between each ring of the conventional stent and an adjacent ring. The connectors in the conventional stent are separated by 90 degrees. For example, the conventional stent may include at least four connectors that between a pair of rings that are circumferentially separated by 90 degrees.

[00134] As shown in FIG. 2B, altering the design of a conventional stent having four connectors results in a significant reduction in bending force required to bend the stent by the 2.0 mm distance. When the stent 10 shown in FIG. 2A is bent in the selected direction about the hinging axis (e g., 90 degree direction), the force is 8% of the force required to bend the conventional stent or a 92% reduction in bending force compared to bending the conventional stent at same direction. When the stent 10 (shown in FIG. 2A) is bent other than about the hinging axis, the stent 10 of FIG. 2A still has a reduced amount of force that is required. For example, to bend the stent 10 at 45 degrees to the direction of the hinging axis, the force is 51% of the force required to bend the conventional stent or a 49% reduction in bending force. When the stent 10 (shown in FIG. 2A) is bent 90 degrees to the direction of the hinging axis, the force is 48% of the force required to bend the conventional stent or a 52% reduction in bending force.

Prophetic example 2

[00135] As previously described, the flexible portion 12 of the stent 10 in FIG. 4A includes pairs of the elongated connectors 16a, 16b, 16c connecting the first ring 18a to the second ring 18b, the second ring 18b to the third ring 18c, and the third ring 18c to the fourth ring 18d, respectively. The two elongated connectors 16a are positioned at the about 0 degree and about 180 degree positions of the stent 10 connecting the first ring 18a to the second ring 18b. The two elongated connectors 16b connect the second ring 18b to the third ring 18c, and these two connectors 16b are located at the about 90 degree and about 270 degree positions. The two elongated connectors 16c are positioned at the about 0 degree and about 180 degree positions of the stent 10 connecting the third ring 18c to the fourth ring 18d. This configuration of connectors 16a, 16b, 16c provides a stent 10 that hinges more easily when stressed in any of the 0 degree, 90 degree, 180 degree, and 270 degree directions depending on which of the elongated connectors 16a, 16b, 16c the bending or hinging is occurring.

[00136] FIG. 4B is a graph illustrating forces that are required to bend the stent 10 illustrated in FIG. 4A by a distance of 2 mm as calculated by finite element analysis, compared to bending of a conventional stent (such as the iCAST/V12 stent sold by Atrium Medical Corporation). The graph demonstrates that by altering the design of a conventional stent having four connectors, a significant reduction in bending force is realized for the stent 10 of FIG. 4A as a whole, and not particularly about a given hinging axis. When the stent 10 with the flexible portion 12 shown in FIG. 4A is bent at 0 degrees, the force is 12% of the force required to bend the control conventional stent or an 88% reduction in bending force. When the stent with the flexible portion 12 shown in FIG. 4A is bent at 45 degrees, the force is 11% of the force required to bend the control conventional stent or an 89% reduction in bending force. When the stent 10 of FIG. 4A is bent at 90 degrees, the force is 16% of the force required to bend the control conventional stent or an 84% reduction in bending force. As noted above, the stent 10 of FIG. 4A is configured to hinge more easily in multiple directions. Accordingly, the resulting reduction in force to hinge the stent 10 of FIG. 4A are substantially similar about the various angles.

Prophetic example 3

[00137] As previously described, the flexible portion 12 of the stent 10 in FIG. 8A includes four elongated connectors 16f, 16g between the first ring 18a and the second ring 18b. The elongated connectors 16f, 16g are paired, with a pair of elongated connectors 16f positioned at about 0 degrees and a pair of elongated connectors 16d positioned at about 180 degrees. The pairs of the elongated connectors 16c, 16d between the second ring 18b and the third ring 18c are circumferentially offset, located at the 90 degree and 270 degree positions. This configuration of the elongated connectors 16c, 16d is also believed to provide a stent 10 that hinges more easily when stressed in any of the 0 degree, 90 degree, 180 degree, and 270 degree directions depending on which of the elongated connectors 16f, 16g the bending or hinging is occurring, as well as in other directions do to proximity to and contribution from the hinge points.

[00138] FIG. 8B is a graph illustrating forces that are required to bend the stent 10 illustrated in FIG. 8A by a distance of up to 2 mm as calculated by finite element analysis. As shown in FIG. 8B, forces for bending the stent 10 of FIG. 8A as a whole and not particularly about a given hinging axis in the 0 degree, 45 degree, 90 degree, 135 degree, and 180 degree directions are similar, requiring between 0.2 N and 0.25 N of force to bend to stent by 1.5 mm. In contrast, nearly 0.5 N force is required to bend a conventional stent (such as the iCAST/V12 stent sold by Atrium Medical Corporation) in any of the 0 degree, 90 degree, 180 degree, or 270 degree directions. As noted above, the stent 10 of FIG. 8A is configured to hinge more easily in multiple directions. Accordingly, the resulting reduction in force to hinge the stent 10 of FIG. 8A are substantially similar about the various angles.

Prophetic example 4

[00139] FIGS. 15A and 15B are visual representations created using finite element analysis to approximate stent behavior during a cantilever bend test comparing a conventional control stent (FIG. 15 A) and a multi -directional hinge stent (FIG. 15B) including features disclosed herein. [00140] The conventional stent (FIG. 15A) is a conventional stainless steel stent including four elongated connectors between each ring and adjacent rings positioned at 0 degrees, 90 degrees, 180 degrees, and 270 degrees. The stent comprising the multi-directional hinge (FIG. 15B) includes two connectors between each ring and adjacent rings separated by several linear segments of the rings, and positioned as shown in FIG. 1 A, IB, and 4A. It is noted that the stents in FIGS. 15A and 15B include the same ring structure and configuration and differ only in positioning and number of the elongated connectors between the rings.

[00141] To create the FEA representations, the stent designs were modeled when expanded to 8 mm diameter and then subjected to a cantilever bend simulation to a distance of 19 mm. FIG. 15A demonstrates that when subjected to this cantilever force, the conventional stent begins to kink to a point where the lumen diameter and cross-sectional area are decreased.

[00142] When a flexible portion of the stent in FIG. 15B including the same ring element structure that incorporates a multi-directional hinge mechanism is subjected to the cantilever force, the bending transition is smooth and without the presence of a kink. These visual representations show that the addition of the multi-directional hinge mechanism allows the stent to create a smooth bend that allows the stent to conform to vessels in any direction.

Working Examples [00143] FIGS. 16A-16E are photographs of prototype stents including hinging mechanisms of the present disclosure, such as the flexible portions of the stents shown in FIGS. 1A, IB, 1C, and 4A. As shown in FIGS. 16A and 16B, the prototype stents bend more easily in one direction to create a curve along a length of the stent. FIG. 16C shows a prototype stent bent in two directions and bent to conform to a sharp corner without kinking. FIG. 16D shows a prototype stent bent in a u-shape configuration. FIG. 16E shows a prototype stent including features of the present disclosure twisted around a rod.

[00144] Although various non-limiting embodiments of the present disclosure have been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred aspects, it is to be understood that such detail is solely for that purpose and that the disclosure is not limited to the disclosed aspects, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present disclosure contemplates that, to the extent possible, one or more features of any aspect can be combined with one or more features of any other aspect.

Claims

CLAIMS:

1. An expandable multi -directional hinging stent configured to radially expand from a compressed configuration to an expanded configuration, the expandable stent comprising: a plurality of radially expandable rings aligned in series along a common axis and defining a common lumen of the expandable stent extending through the plurality of rings, wherein the plurality of rings comprises at least a first ring, a second ring, and a third ring aligned in series; and a plurality of elongated connectors extending between the plurality of rings comprising (i) a first group including a first elongated connector and a second elongated connector, the first and second connectors coupling the first ring to the second ring to form a first hinging axis extending through the first and second connectors about which the expandable stent is configured to bend in a first direction and (ii) a second group including a third elongated connector and a fourth elongated connector, the third and fourth connectors coupling the second ring to the third ring to form a second hinging axis extending through the third and fourth connectors about which the expandable stent is configured to bend in a second direction, wherein the first group of elongated connectors is axially and circumferentially offset from the second group of elongated connectors.

2. The expandable stent of claim 1, wherein the first group of elongated connectors is positioned such that a bending force required to bend the stent at the first hinging axis by a predetermined distance in the first direction is less than a bending force required to bend the stent at the first hinging axis by the predetermined distance in the second direction.

3. The expandable stent of claim 1, wherein the second group of elongated connectors is positioned such that a bending force required to bend the stent at the second hinging axis by a predetermined distance in the second direction is less than a bending force required to bend the stent at the second hinging axis by the predetermined distance in the first direction.

4. The expandable stent of claim 1, wherein the first and second elongated connectors are immediately adjacent to one another and are circumferentially spaced apart by at least 90 degrees about a circumference of the stent.

5. The expandable stent of claim 1, wherein the elongated connectors of the first group are circumferentially offset from the elongated connectors of the second group by between 60 degrees and 90 degrees about a circumference of the stent.

6. The expandable stent of claim 1, wherein the first and second elongated connectors are one of circumferentially spaced apart from each other by less than 90 degrees about a circumference of the stent or are circumferentially spaced apart from one another by at least 90 degrees about the circumference of the stent.

7. The expandable stent of claim 6, wherein the first group of elongated connectors includes a fifth elongated connector and a sixth elongated connector spaced from one another circumferentially in a manner symmetrical to the first and second elongated connectors about the common axis of the stent.

8. The expandable stent of claim 6, wherein the third and fourth elongated connectors are one of circumferentially spaced apart from each other by less than 90 degrees about the circumference of the stent and circumferentially spaced apart from one another by at least 90 degrees about the circumference of the stent.

9. The expandable stent of claim 1, wherein the plurality of elongated connectors comprises at least one of a bent portion, a curved portion, a straight portion, or a pigtailed portion.

10. The expandable stent of claim 1, wherein at least one of the plurality of rings or the plurality of elongated connectors comprises a biocompatible alloy, a biocompatible polymer, or a bioabsorbable material.

11. The expandable stent of claim 1, wherein at least one of the plurality of rings or the plurality of elongated connectors comprises stainless steel, cobalt chromium, or a nickel-titanium alloy.

12. The expandable stent of claim 1, further comprising a cover over at least a portion of the plurality of rings, wherein the cover comprises polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE).

13. The expandable stent of claim 1, wherein each of the plurality of rings comprises multiple linear segments connected together end-to-end forming peaks and valleys of the ring.

14. The expandable stent of claim 13, wherein at least one of the plurality of elongated connectors is connected to one of the plurality of rings at a substantially middle point of the linear segment of the ring between the peaks and valleys of the ring.

15. The expandable stent of claim 13, wherein the plurality of elongated connectors is arranged forming two axially extending spirals through the plurality of rings, and wherein: the first and second elongated connectors are circumferentially offset by at least one linear segment from the third and fourth elongated connectors; and connection points on the second ring for the first and second elongated connectors are circumferentially offset from connection points on the second ring for the third and fourth elongated connectors that extend to the third ring.

16. The expandable stent of claim 13, wherein at least one of the plurality of elongated connectors is connected to one of the plurality of rings at a point on the linear segment closer to one of the peak or the valley of the ring than to the other of the peak or the valley of the ring.

17. The expandable stent of claim 13, wherein at least one of the elongated connectors comprises an angled section that is angled relative to the common axis of the stent, an end of the angled section connecting the elongated connector to the linear segment.

18. The expandable stent of claim 17, wherein each of the first and second elongated connectors comprises a first end connected to one of the linear segments of the first ring and a second end connected to one of the linear segments of the second ring that is not axially aligned with the linear segment of the first ring to which the first end is attached.

19. The expandable stent of claim 1, further comprising at least one rigid section comprising: a plurality of radially expandable rings of the rigid section that are aligned in series along the common axis and defining a portion of the common lumen of the stent; and a plurality of elongated connectors extending between rings of the plurality of rings of the rigid section, wherein at least three elongated connectors extend between each ring and an immediately adjacent ring of the plurality of radially expandable rings of the rigid section, each elongated connector being separated from each immediately adjacent elongated connector by no more than 120 degrees.

20. An expandable stent configured to radially expand from a compressed configuration to an expanded configuration, the expandable stent comprising: a plurality of radially expandable rings aligned in series along a common axis and defining a common lumen of the expandable stent extending through the plurality of rings; and a plurality of elongated connectors extending between the plurality of rings comprising at least a first pair of elongated connectors extending between a first one of the plurality of rings and a second one of the plurality of rings immediately adjacent to the first ring and a second pair of elongated connectors extending between the first ring and the second ring, wherein the elongated connectors of each pair are spaced apart from each other by less than 90 degrees about a circumference of the expandable stent and the elongated connectors of the first pair are circumferentially spaced apart from the elongated connectors of the second pair by more than 90 degrees.