Stent system for maintaining patency of body lumen

Abstract

A system for maintaining patency of a body lumen may include a first endoprosthesis configured to transition from a straight configuration to a helical configuration forming a plurality of loops, and a second endoprosthesis configured to transition from a radially contracted configuration to a radially expanded configuration. The plurality of loops define a passageway having an inner diameter. At least a portion of the second endoprosthesis is disposed within the passageway in the radially expanded configuration.

Description

Technical Field

[0001] The present disclosure relates to medical devices and methods for manufacturing and / or using medical devices. More specifically, the present disclosure relates to an improved design for a stent system for maintaining the patency of a body lumen at a bifurcation.

Background Art

[0002] One currently known procedure for alleviating biliary obstruction in the biliary system is the placement of a coated endoprosthesis or stent into a restricted body lumen (e.g., bile duct, pancreatic duct, etc.) such as caused by stenosis. For example, it may be necessary to open a body lumen (e.g., bile duct, pancreatic duct, etc.) to relieve symptoms associated with acute pain and to allow the passage of debris associated with bile and stones. In addition, the biliary system has several branches, bifurcations, and / or adjacent lumens. Placing a coated endoprosthesis or stent beyond the opening of a bifurcation and / or adjacent branch or lumen to treat a stenosed or occluded body lumen may result in further occlusion of currently open or unrestricted lumens, which may be undesirable. There is still a need to provide alternative endoprostheses or stents, as well as alternative methods for manufacturing and using endoprostheses or stents.

Summary of the Invention

[0003] In one example, a system for maintaining the patency of a body lumen may include a first endoprosthesis having a lumen extending from a first end to a second end, the first endoprosthesis configured to transition from a linear configuration to a helical configuration forming a plurality of loops, and a second endoprosthesis configured to transition from a radially contracted configuration to a radially expanded configuration. The plurality of loops may define a passage having an inner diameter. At least a portion of the second endoprosthesis may be disposed within the passage in a radially expanded configuration.

[0004] In addition to or alternative to any of the examples described herein, when the second internal prosthesis is positioned within the passage in a radially extending manner, at least a portion of the second internal prosthesis extends away from the passage.

[0005] In addition to or alternative to any of the examples described herein, at least a portion of the first in-vivo prosthesis extends away from the multiple loops. In addition to or alternative to any of the examples described herein, when the second implantable prosthesis is positioned within the passage in a radially extending configuration, the first end portion of the first implantable prosthesis extends laterally from the second implantable prosthesis with respect to the central longitudinal axis of the second implantable prosthesis.

[0006] In addition to or alternative to any of the examples described herein, when the second implantable prosthesis is positioned within the passage in a radially extending configuration, the second end portion of the first implantable prosthesis extends away from the second implantable prosthesis substantially parallel to the central longitudinal axis of the second implantable prosthesis.

[0007] In addition to or alternative to any of the examples described herein, the first in-vivo prosthesis is formed from a polymer material. In addition to or alternative to any example described herein, a system for maintaining the patency of a body lumen may comprise a first internal prosthesis having a lumen extending from a first end to a second end, configured to transition from a linear configuration to a helical configuration forming a plurality of loops, and a second internal prosthesis configured to transition from a radially contracting configuration to a radially expanding configuration. The plurality of loops may define a passage having an inner diameter. The second internal prosthesis may be configured to be positioned within the passage. The second internal prosthesis may have an outer diameter in the radially expanding configuration. The outer diameter of the second internal prosthesis may be within 20% of the inner diameter of the passage.

[0008] In addition to or alternative to any of the examples described herein, multiple loops define an outer diameter of approximately 6 French to approximately 12 French. In addition to or alternative to any of the examples described herein, the first in-vivo prosthesis is self-biased toward a helical form.

[0009] In addition to or as an alternative to any of the examples described herein, a second in-vivo prosthesis is self-biased toward a radially expanding form. In addition to or alternative to any of the examples described herein, the second internal prosthesis includes a polymer cover extending along at least a portion of the length of the second internal prosthesis.

[0010] In addition to or alternative to any of the examples described herein, the first internal prosthesis includes a corrugated section positioned between the first end and a plurality of loops.

[0011] In addition to or alternative to any example described herein, the first internal prosthesis includes one or more drainage holes extending through the side wall of the first internal prosthesis. In addition to or alternative to any of the examples described herein, the first internal prosthesis includes one or more anti-movement elements extending radially outward from the first internal prosthesis.

[0012] In addition to or alternative to any example described herein, a method for maintaining the patency of a body lumen may include the steps of advancing a first internal prosthesis in a linear configuration into a first body lumen; unfolding the first internal prosthesis into a helical configuration forming a plurality of loops within the first body lumen; advancing a second internal prosthesis into the first body lumen in a radially contracting configuration; and transitioning the second internal prosthesis into a radially expanding configuration within the plurality of loops.

[0013] In addition to or alternative to any example described herein, the step of advancing the first internal prosthesis linearly into a first body lumen includes positioning the first end portion of the first internal prosthesis into a second body lumen adjacent to the first body lumen.

[0014] In addition to or alternative to any of the examples described herein, when the second implantable prosthesis is arranged in a radially extending form within a plurality of loops, the first end portion of the first implantable prosthesis extends laterally from the second implantable prosthesis with respect to the central longitudinal axis of the second implantable prosthesis.

[0015] In addition to or alternative to any of the examples described herein, the first internal prosthesis is self-biased toward a helical shape when unrestrained. In addition to or alternative to any of the examples described herein, the first internal prosthesis is constrained to a linear shape by a guidewire when the first internal prosthesis is advanced into the first body lumen.

[0016] In addition to or alternative to any of the examples described herein, the first internal prosthesis is constrained to a linear shape by a delivery sheath when the first internal prosthesis is advanced into the first body lumen.

[0017] The above summary of some embodiments, aspects, and / or examples is not intended to describe each or all embodiments disclosed in this disclosure. The following drawings and detailed description (Modes for Carrying Out the Invention) illustrate these embodiments in more detail. [Brief explanation of the drawing]

[0018] This disclosure can be understood more fully by considering the following detailed description in relation to the attached drawings. [Figure 1] This figure shows selected embodiments of a stent system for maintaining the patency of a body lumen and a method for using the stent system. [Figure 2] FIG. showing selected aspects of a stent system for maintaining the patency of a body lumen and a method of using the stent system. [Figure 3] FIG. showing selected aspects of a stent system for maintaining the patency of a body lumen and a method of using the stent system. [Figure 4] FIG. showing selected aspects of a stent system for maintaining the patency of a body lumen and a method of using the stent system. [Figure 5] FIG. showing selected aspects of the stents of the stent system of FIGS. 1-4. [Figure 6] FIG. showing selected aspects of an alternative configuration of the stent of FIG. 5. [Figure 7] FIG. showing selected aspects of a stent system for maintaining the patency of a body lumen. DETAILED DESCRIPTION OF THE INVENTION

[0019] Aspects of the present disclosure are capable of various modifications and alternative forms, and specific ones thereof are shown by way of example in the drawings and will be described in detail below. However, it should be understood that the intention is not to limit the aspects of the present disclosure to the specific embodiments described. On the contrary, it is intended to cover all modifications, equivalents, and alternative forms within the spirit and scope of the present disclosure.

[0020] The following description should be read with reference to the drawings which are not necessarily to scale, and in which like reference numerals indicate like elements throughout several views. The detailed description and the drawings are intended to illustrate rather than limit the present disclosure. Those skilled in the art will understand that the various elements described and / or illustrated can be arranged in various combinations and configurations without departing from the scope of the present disclosure. The detailed description and the drawings illustrate embodiments of the present disclosure.

[0021] For the terms defined below, these definitions shall apply unless otherwise defined in the claims or elsewhere in this specification. In this specification, all numerical values are assumed to be modified by the term "about", whether or not explicitly indicated. The term "about" in the context of numerical values generally refers to a range of numbers that those skilled in the art would consider equivalent to the recited value (e.g., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant digit. Other uses of the term "about" (in contexts other than numerical values) may be assumed to have their ordinary customary definitions as understood from and consistent with the context of this specification, unless otherwise specified.

[0022] The recitation of numerical ranges by endpoints includes all numbers within that range including those endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Although some preferred dimensions, ranges, and / or values for various components, features, and / or specifications are disclosed, those skilled in the art will appreciate that the desired dimensions, ranges, and / or values may deviate from those explicitly disclosed.

[0023] In this specification and the appended claims, the singular forms “a, an” and “the” refer to multiple subjects unless otherwise explicitly indicated in the content. In this specification and the appended claims, the term “or” is generally used to mean “and / or” unless otherwise explicitly indicated in the content. For ease of understanding, note that some features of this disclosure may be described singularly, even if they are plural or occur repeatedly within the disclosed embodiments. Each instance of a feature may include and / or be included in a singular disclosure unless explicitly stated otherwise. For simplicity and clarity, not all elements of this disclosure are necessarily shown in each figure or discussed in detail below. However, it should be understood that the following discussion may apply equally to any and / or all of the components that exist in pairs or more, unless explicitly stated otherwise.

[0024] Relative terms such as “proximal,” “distal,” “forward,” “backward,” and their variations may generally be considered in relation to the positioning, orientation, and / or movement of various elements of the apparatus with respect to the user / operator / maneuverer, where “proximal” and “backward” indicate or point towards or toward the user, and “distal” and “forward” indicate or point towards or away from the user. Where appropriate, the terms “proximal” and “distal” may be arbitrarily assigned to facilitate understanding of this disclosure, in which case it will be readily apparent to those skilled in the art. Other relative terms such as “upstream,” “downstream,” “inflow,” and “outflow” refer to the direction of fluid flow within a lumen, such as a body lumen, a blood vessel, or within an apparatus. Still other relative terms such as “axial,” “circumferential,” “longitudinal,” “lateral,” “radial,” and / or their variations generally refer to the direction and / or orientation with respect to the central longitudinal axis of the disclosed structure or apparatus.

[0025] The term “range” may be understood to mean the minimum measurement of the stated or specified dimension, unless the range or dimension is specifically designated as “minimum.” For example, “outer range” may be understood to mean the outer dimension, “radial range” may be understood to mean the radial dimension, and “longitudinal range” may be understood to mean the longitudinal dimension, and so on. A “range” may vary from case to case (e.g., axial, longitudinal, transverse, radial, circumferential, etc.) and will be apparent to a person skilled in the art from the context of the individual use. Generally, a “range” may be considered the maximum possible dimension measured according to the intended use, and a “minimum range” may be considered the minimum possible dimension measured according to the intended use. Depending on the context, a certain "range" may generally be measured diagonally within a plane and / or cross-section, but as is evident from the specific context, it may also be measured differently (but not limited to obliquely, radially, circumferentially (e.g., along an arc), etc.).

[0026] The terms “monolithic” and “integrated” generally refer to one or more elements made from or consisting of a single structure or basic unit / element. Monolithic and / or integrated elements exclude structures and / or features made by assembling or otherwise joining together multiple separate structures or elements.

[0027] References in the specification such as "one embodiment," "several embodiments," and "other embodiments" indicate that the embodiments described may include certain features, structures, or characteristics, but not all embodiments necessarily include those features, structures, or characteristics. Furthermore, such phrasing does not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or measurement is described in relation to one embodiment, it is within the knowledge of those skilled in the art to implement that particular feature, structure, or characteristic in relation to other embodiments, whether or not it is explicitly stated, unless otherwise explicitly stated. That is, the various individual elements described below are assumed to be combinable or configurable with respect to each other to form other additional embodiments or to complement and / or enhance the embodiments described, as will be understood by those skilled in the art, even if they are not explicitly shown in specific combinations.

[0028] For clarity, certain numerical nomenclature (e.g., First, Second, Third, Fourth, etc.) may be used throughout the specification and claims to name and / or identify various features described and / or claimed. This numerical nomenclature should be understood to be illustrative and not intended to be restrictive. In some embodiments, for the sake of brevity and clarity, it may be modified or omitted from previously used numerical nomenclature. That is, a feature identified as the “First” element may later be referred to as the “Second” element, the “Third” element, etc., or may be omitted entirely, and / or a different feature may be referred to as the “First” element. The meaning and / or designation in each instance will be obvious to those skilled in the art.

[0029] The diagrams illustrate selected components and / or arrangements of the system. It should be noted that in any given diagram, some features of the system may be omitted or represented schematically for the sake of simplicity. Additional details regarding some of the system's components may be shown in more detail in other diagrams. For ease of understanding, note that some features of this disclosure may be described singularly, even if they may occur multiple times or repeatedly within the disclosed embodiments. Each instance of a feature may include and / or be encompassed within a singular disclosure unless explicitly stated otherwise. Thus, it should be understood that the following considerations may apply equally to any and / or all of the multiple components present in the system unless explicitly stated otherwise. Furthermore, for clarity, not all instances of certain elements or features may be shown in each diagram.

[0030] The following disclosure describes aspects of a stent system. For clarity and / or brevity, the term “stent” will be used herein and will include, but not be limited to, other similar technical terms such as “internal prosthesis.” This disclosure also refers to the treatment of body lumens, in particular body lumens having bifurcations and / or adjacent bifurcations. For brevity, the term “body lumen” includes, but is not limited to, certain body lumens such as the bile duct, hepatic duct, cystic duct, common bile duct, pancreatic duct, and bronchi. This system is also intended for use in other body lumens.

[0031] Figure 1 illustrates selected features of a first body lumen 10 and a second body lumen 20 adjacent to the first body lumen 10 (e.g., a bifurcated lumen). In some examples, the first body lumen 10 and the second body lumen 20 may merge at a bifurcation 12. In other words, the second body lumen 20 may branch off or diverge from the first body lumen 10 at the bifurcation 12, or the first body lumen 10 may branch off or diverge from the second body lumen 20 at the bifurcation 12. Thus, the first body lumen 10 and the second body lumen 20 may be connected or joined at the bifurcation 12. As shown in Figure 1, the first body lumen 10 may include a constriction 14 (e.g., an occlusion) located along the inner surface of the wall of the first body lumen 10. As shown in Figure 1, the constriction 14 may be located, for example, upstream of the bifurcation 12. However, in other cases, the stenosis 14 may be located downstream of the bifurcation 12. If a covered internal prosthesis or stent is placed in the stenosis 14 formed within the first lumen 10, the covered internal prosthesis or stent will straddle the bifurcation 12, potentially partially or completely occluding the second lumen 20. Consequently, fluid flowing from the second lumen 20 may be prevented from flowing downstream into the first lumen 10. When treating the first lumen 10, it is desirable to maintain the patency of the second lumen 20 to allow fluid to flow from the second lumen 20 into the first lumen 10.

[0032] A method for maintaining the patency of a body lumen using the system disclosed herein may include the step of advancing a guidewire 90 into a first body lumen 10. In some embodiments, the method may further include the step of advancing the guidewire 90 from the first body lumen 10 into a second body lumen 20 upstream of the bifurcation 12. The method may include the step of advancing a first internal prosthesis 100 in a linear configuration on the guidewire 90 into the first body lumen 10, as shown in Figure 1. It should be understood that the term “internal prosthesis” as used herein may be used interchangeably with the term “stent.” In some embodiments, when advancing the first internal prosthesis 100 through the first body lumen 10 into the second body lumen 20, the first internal prosthesis 100 may be constrained in a linear configuration by the guidewire 90. In some alternative embodiments, when advancing the first internal prosthesis 100 through the first body lumen 10 into the second body lumen 20, the first internal prosthesis 100 may be constrained to a linear shape by a delivery sheath (not shown) surrounding the first internal prosthesis 100. Other configurations, including combinations thereof, are also conceivable.

[0033] In some embodiments, as shown in Figure 1, advancing the first internal prosthesis 100 linearly through the first body lumen 10 downstream of the bifurcation 14 into the second body lumen 20 may include positioning the first end portion 110 of the first internal prosthesis 100 in the second body lumen 20, such as upstream of the bifurcation 12, and leaving the second end portion 112 of the first internal prosthesis 100 in the first body lumen 10, such as downstream of the bifurcation 12.

[0034] The method may include the step of unfolding the first internal prosthesis 100 into a helical shape, with the first end portion 110 of the first internal prosthesis 100 located in a second body lumen 20, such as upstream of the bifurcation 12, and the second end portion 112 of the first internal prosthesis 100 located in a first body lumen 10, such as downstream of the bifurcation 12. Thus, the middle portion of the first internal prosthesis 100 may be located at the bifurcation 12 when unfolded into a helical shape. When unfolded into a helical shape, the middle portion of the first internal prosthesis 100 may form a plurality of helical loops 130, as shown in Figure 2. As shown in Figure 2, the first internal prosthesis 100 can be deployed at the bifurcation with multiple helical loops 130 positioned in the first body lumen 10 proximal (e.g., downstream) of the bifurcation 12, and the first end region 110 of the internal prosthesis 100 positioned in the second body lumen 10 distal (e.g., upstream) of the bifurcation 12. In the deployed helical configuration, the radially outward spreading of the helical loops 130 may contact and / or press radially outward against the inner surface of the first body lumen 10. The first internal prosthesis 100 may be configured to automatically transition from a linear configuration (with the helical loops 130 straightened or elongated) when constrained by the guidewire 90 (or the outer sheath, if an outer sheath is present) to a helical configuration when unconstrained (e.g., Figures 2 and 5). In at least some embodiments, the first internal prosthesis 100 may be self-biased toward a helical configuration when unconstrained.

[0035] Referring briefly to Figure 5, a selected embodiment of the first implantable prosthesis 100 is shown in more detail, which may have a lumen 102 extending from a first end 104 to a second end 106. In some embodiments, during use, the first end 104 may be the distal end of the first implantable prosthesis 100 and the second end 106 may be the proximal end, but this is not mandatory.

[0036] In some embodiments, at least a portion of the first implantable prosthesis 100 may extend away from the helical loops 130. In some embodiments, a first end portion 110 may extend away from the helical loops 130. In some embodiments, the first end portion 110 may extend from the helical loops 130 to the first end 104 of the first implantable prosthesis 100. In some embodiments, a second end portion 112 may extend away from the helical loops 130. In some embodiments, the second end portion 112 may extend from the helical loops 130 to the second end 106 of the first implantable prosthesis 100.

[0037] In some embodiments, the first internal prosthesis 100 may include one or more anti-movement elements 120. In some embodiments, one or more anti-movement elements 120 may be formed integrally with and / or monolithically with the first internal prosthesis 100. In some embodiments, one or more anti-movement elements 120 may be configured to be substantially flush with the outer surface of the first internal prosthesis 100 in a linear configuration (for example, when the first internal prosthesis 100 is constrained to a linear configuration) and / or during advancement into and / or delivery into the first body lumen 10, as shown in Figure 1.

[0038] In some embodiments, one or more anti-movement elements 120 may be configured to extend radially outward from the first internal prosthesis 100 in a helical configuration and / or in an unrestrained state, as shown in Figures 2 and 5. In some embodiments, one or more anti-movement elements 120 may be positioned within the range of a first end portion 110 and / or a second end portion 112. In some embodiments, one (or more) of the one or more anti-movement elements 120 may be positioned within the range of the first end portion 110, and one (or more) of the one or more anti-movement elements 120 may be positioned within the range of the second end portion 112. In some embodiments, one or more anti-movement elements 120 may be positioned only within the range of the first end portion 110. In some embodiments, one or more anti-movement elements 120 may be positioned only within the range of the second end portion 112. In some embodiments, one or more anti-misalignment elements 120 may be self-biased to extend radially outward from the first internal prosthesis 100 in a helical configuration. In some embodiments, the first internal prosthesis 100 may include a mechanism configured to bias one or more anti-misalignment elements 120 to extend radially outward from the first internal prosthesis 100 in a helical configuration. Other configurations are also conceivable. One or more anti-misalignment elements 120 may be configured to engage with the inner surface of the body lumen in which the first internal prosthesis 100 is located (for example, one or more anti-misalignment elements 120 may be configured to engage with the inner surface of the first body lumen 10 and / or the second body lumen 20). In some examples, the anti-misalignment elements 120 may be barbs (spine-like projections) extending from the tubular wall of the first internal prosthesis. In other embodiments, the anti-movement element 120 may be a pigtail or spiral anchor located at the first end portion 110 and / or the second end portion 112.

[0039] Referring again to Figure 5, in some embodiments, the first internal prosthesis 100 may include one or more drainage ports 140 extending through the side walls of the first internal prosthesis 100. One or more drainage ports 140 may be in fluid communication with the lumen 102. One or more drainage ports 140 may be located along a first end portion 110, a second end portion 112, and / or a plurality of helical loops 130. In Figure 5, they are shown located along the first end portion 110 and the second end portion 112, but in some embodiments, one or more drainage ports 140 may be located along only the first end portion 110, along only the second end portion 112, and / or along only the plurality of helical loops 130. In some embodiments, one or more drainage ports 140 may be located along substantially the entire length of the first internal prosthesis 100, or along any portion thereof.

[0040] In some embodiments, the multiple helical loops 130 form a passage 150 having an inner diameter 132. In some embodiments, the multiple helical loops 130 may extend circumferentially around the passage 150 and / or the longitudinal axis of the passage 150. In at least some embodiments, the multiple helical loops 130 may extend spirally around the passage 150 and / or the longitudinal axis of the passage 150 in a helical configuration.

[0041] The passage 150 may be outlined by the inner extent of a plurality of helical loops 130 formed by the outer surface of the tubular wall of the first internal prosthesis 100. The plurality of helical loops 130 may define the outer diameter 134 and / or outermost extent formed by the outer surface of the tubular wall of the first internal prosthesis 100. In some embodiments, the outer diameter 134 and / or outermost extent of the plurality of helical loops 130 may be about 6 French (Fr) to about 15 Fr (e.g., about 2 mm to about 5 mm). In some embodiments, the outer diameter 134 and / or outermost extent of the plurality of helical loops 130 may be about 6 Fr to about 12 Fr (e.g., about 2 mm to about 4 mm). In some embodiments, the outer diameter 134 and / or outermost range of the multiple helical loops 130 may be about 6 Fr (e.g., about 2 mm), about 7 Fr (e.g., about 2.33 mm), about 8 Fr (e.g., about 2.67 mm), about 9 Fr (e.g., about 3 mm), about 10 Fr (e.g., about 3.33 mm), about 11 Fr (e.g., about 3.67 mm), about 12 Fr (e.g., about 4 mm), about 13 Fr (e.g., about 4.33 mm), about 14 Fr (e.g., about 4.67 mm), about 15 Fr (e.g., about 5 mm), etc.

[0042] In some embodiments, the elongated tube of the first internal prosthesis 100 may have a first total length in a linear form of approximately 40 mm to approximately 300 mm, approximately 50 mm to approximately 275 mm, approximately 60 mm to approximately 250 mm, approximately 80 mm to approximately 225 mm, approximately 100 mm to approximately 200 mm, approximately 110 mm to approximately 175 mm, or another suitable range.

[0043] In at least some embodiments, the first internal prosthesis 100 may be formed from a polymer material. For example, the first internal prosthesis 100 may be formed from a polymer tubular member extending from a first end 104 to a second end 106 of the first internal prosthesis 100. The polymer tubular member may maintain a constant diameter as the first internal prosthesis 100 transitions between a linear and a helical form. In other words, the polymer tubular member may be a polymer tube that does not significantly expand radially as the first internal prosthesis 100 transitions from a linear to a helical form, and thus maintains a constant diameter. The polymer tubular member may be formed (e.g., heat-set) to include a helical loop 130 along an intermediate region of the polymer tubular member when unconstrained. When the polymer tubular member is stretched and thus becomes linear, the helical loop 130 may disappear, providing the linear form when constrained for delivery to the branch 12. This specification describes some suitable and non-limiting examples of materials for a first in-vivo prosthesis 100.

[0044] Referring here to Figure 3, once the first internal prosthesis 100 has been delivered beyond the bifurcation 12 and expanded into a helical shape, the method may include the step of advancing the guidewire 190 into the first body lumen 10. After the first internal prosthesis has been expanded into a helical shape, the method may further include the step of advancing the guidewire 190 into and / or through the helical loops 130 and / or through the passage 150 of the first internal prosthesis 100. The method may further include the step of advancing the second internal prosthesis 200 into the first body lumen 10 in a radially contracting shape along the guidewire 190. Accordingly, the second internal prosthesis 200 may be positioned within the helical loop 130 in a radially constrained or contracted form, such that the helical loop 130 surrounds the second internal prosthesis 200 which is radially constrained or contracted, in which case the second internal prosthesis 200 extends from a portion of the first body lumen 10 proximal to (e.g., downstream of) the bifurcation 12 to a portion of the first body lumen 10 distal to (e.g., upstream of) the bifurcation 12. The second internal prosthesis 200 may be positioned such that its distal end region extends beyond the stenosis 14 (in the first body lumen 10 upstream of the bifurcation 12) in a radially constrained or contracted manner, and its proximal end region passes through the helical loop 130 of the first internal prosthesis 100 in the first body lumen 10 downstream of the bifurcation 12.

[0045] The second internal prosthesis 200 may be configured to transition from a radially contracted form to a radially expanded form (e.g., Figure 4). In at least some embodiments, the second internal prosthesis 200 may be self-biased toward the radially expanded form. In some embodiments, the second internal prosthesis 200 may be formed from a superelastic material such as nitinol and / or a shape memory material. In some embodiments, the second internal prosthesis 200 may be constrained to the radially contracted form by the properties of the shape memory material when the second internal prosthesis 200 is advanced into the first body lumen 10. In some embodiments, the second internal prosthesis 200 may be constrained to the radially contracted form by a delivery sheath 210 surrounding the second internal prosthesis 200 when the second internal prosthesis 200 is advanced into the first body lumen 10, as shown in Figure 3. Other configurations, including combinations thereof, are also conceivable.

[0046] The second internal prosthesis 200 may include an expandable framework extending axially from a first end (which may be considered a proximal end in some examples) to a second end (which may be considered a distal end in some examples) along the central longitudinal axis of the second internal prosthesis 200 and / or the expandable framework. In at least some embodiments, the second internal prosthesis 200 and / or the expandable framework may be self-expandable when unrestrained. In some embodiments, the second internal prosthesis 200 and / or the expandable framework may be mechanically expandable. For example, the second internal prosthesis 200 and / or the expandable framework may be expandable using an inflatable balloon, using an actuarial member, or using other suitable means.

[0047] The expandable framework may include and / or be formed from multiple cells. In some embodiments, the expandable framework may include and / or be formed from one or more filaments woven around the central longitudinal axis of the second internal prosthesis 200 and / or the expandable framework. In at least some embodiments, one or more filaments may form and / or define multiple cells. In some embodiments, the expandable framework may be braided, knitted, or woven from one or more filaments. In some embodiments, one or more filaments may be wires, threads, strands, etc. In some embodiments, adjacent filaments of one or more filaments may define cells (i.e., openings or gaps) that penetrate the walls of the expandable framework. Alternatively, in some embodiments, the expandable framework may be a monolithic structure formed from cylindrical tubular members, such as a single cylindrical laser-cut nickel-titanium (e.g., nitinol) tubular member, where the remaining (e.g., unremoved) portions of the tubular member form stent columns and / or framework with cells (i.e., openings or gaps) defined between them.

[0048] The second internal prosthesis 200 and / or expandable framework may be substantially tubular and / or include and / or form a lumen that extends axially through from the first end to the second end along the central longitudinal axis of the second internal prosthesis 200 and / or expandable framework. In some embodiments, the second internal prosthesis 200 and / or expandable framework may have an axial length of about 20 mm to about 200 mm, about 30 mm to about 175 mm, about 40 mm to about 150 mm, about 50 mm to about 125 mm, about 75 mm to about 100 mm, or another suitable range. In some embodiments, the second internal prosthesis 200 and / or expandable framework may have an outer diameter of about 0.5 mm to about 5 mm, about 0.75 mm to about 4.5 mm, about 1 mm to about 4 mm, about 1.5 mm to about 3.5 mm, or another suitable range. In some embodiments, the second internal prosthesis 200 and / or expandable framework may have outer diameters of approximately 4 mm to approximately 28 mm, approximately 4 mm to approximately 14 mm, approximately 14 mm to approximately 28 mm, and / or other subsets thereof. Other configurations are also contemplated. Some suitable but non-limiting materials for the second internal prosthesis 200, the expandable framework, and / or their components or elements, such as metallic materials and / or polymer materials, are described below.

[0049] In some embodiments, the first total length of the elongated tube of the first implantable prosthesis 100 in a linear configuration may relate to the axial length of the second implantable prosthesis 200. As illustrated and / or described herein, at least portions of the first end portion 110 and the second end portion 112 of the first implantable prosthesis 100 may extend proximal and distal to the second implantable prosthesis 200, respectively. In some embodiments, the first total length of the first implantable prosthesis 100 in a linear configuration may be approximated as the axial length of the second implantable prosthesis 200 + (circumference of the second implantable prosthesis 200 × number of helical loops of the plurality of helical loops 130) + the lengths of the first end portion 110 and the second end portion 112 of the first implantable prosthesis 100 extending away from each end of the second implantable prosthesis 200.

[0050] The approximate total length of the elongated tube of the first implantable prosthesis 100 in its helical form is shorter than the total length of the first. In a non-limiting example, the axial length of the second implantable prosthesis 200 may be approximately 100 millimeters, and the outer diameter of the second implantable prosthesis 200 may be approximately 10 millimeters. An example of the first implantable prosthesis 100 associated with and / or used in conjunction with the example of the second implantable prosthesis 200 described above has a first total length of approximately 300 millimeters in a linear form and an approximate total length of approximately 120 millimeters in a helical form. Other configurations and / or examples are also contemplated.

[0051] In some embodiments, the expandable framework may include a first flared portion adjacent to the first end of the expandable framework. The first flared portion may extend from the first end toward the second end. In some embodiments, the expandable framework may include a second flared portion adjacent to the second end of the expandable framework. The second flared portion may extend from the second end toward the first end. In at least some embodiments, the second flared portion may be spaced longitudinally and / or axially apart from the first flared portion by the main body portion. In some embodiments, the first flared portion and / or the second flared portion may be configured to exert a radially outward force on the wall of the first body lumen 10 to prevent the second internal prosthesis 200 from moving within the first body lumen 10.

[0052] In some embodiments, the delivery sheath 210 may be a long catheter or other tubular shaft suitable for delivering an in-vivo prosthesis and / or known in the art for delivering an in-vivo prosthesis. The second in-vivo prosthesis 200 may be positioned within the lumen of the delivery sheath 210 in a radially constrained or contracted configuration. In the radially constrained or contracted configuration, the expandable framework may be stretched substantially linearly and / or fully. The second in-vivo prosthesis 200 may be deployed from the delivery sheath 210 by using one or more known techniques, such as withdrawing the delivery sheath 210 proximal to the second in-vivo prosthesis 200 to discharge the second in-vivo prosthesis 200 from the delivery sheath 210. Other commonly known techniques, but not described for brevity, may be used to deploy the second in-vivo prosthesis 200 from the delivery sheath 210.

[0053] The method may include the step of transitioning the second internal prosthesis 200 to a radially expanding form within a plurality of loops 130 and / or passages 150, as shown in Figure 4. In some embodiments, the step of transitioning the second internal prosthesis 200 to a radially expanding form may include drawing out and / or retracting the delivery sheath 210 relative to the second internal prosthesis 200 to expose the second internal prosthesis 200 within the first body lumen 10 and / or within the plurality of loops 130 and / or passages 150, thereby allowing the second internal prosthesis 200 to expand radially.

[0054] In at least some embodiments, the second internal prosthesis 200 and / or expandable framework may be deployed within a body lumen extending through a stenosis to maintain and / or re-establish the patency of the body lumen. In some embodiments, the second internal prosthesis 200 and / or expandable framework may be configured to expand at least a portion of the body lumen in a radial expansion configuration. For example, the second internal prosthesis 200 and / or expandable framework may be configured to exert a radially outward force against the wall of the body lumen and / or against a stenosis formed within the body lumen.

[0055] In some embodiments, at least a portion of the second implantable prosthesis 200 may be positioned within a plurality of loops 130 and / or passages 150 in a radially expanding configuration. In some embodiments, when the second implantable prosthesis 200 is positioned within a plurality of loops 130 and / or passages 150 in a radially expanding configuration, at least a portion of the second implantable prosthesis 200 may extend away from the plurality of loops 130 and / or passages 150.

[0056] In some embodiments, the second internal prosthesis 200 and / or expandable framework may be configured to engage with a plurality of loops 130 and / or passages 150 in a radial expansion configuration. In a radial expansion configuration, the second internal prosthesis 200 and / or expandable framework may be configured to apply a radially outward force to the first internal prosthesis 100 and / or the plurality of loops 130 in a helical configuration, thereby engaging and / or pressing the first internal prosthesis 100 and / or the plurality of loops 130 against the wall of the first body lumen 10. In some examples, a portion of the second internal prosthesis 200 extending between adjacent loops 130 may extend radially outward and come into contact with the wall of the first body lumen 10.

[0057] In some embodiments, the second internal prosthesis 200 may be configured to expand at least a portion of the first lumen 10 in a radial expansion configuration. For example, the second internal prosthesis 200 may be configured to exert a radially outward force on the wall and / or constriction 14 of the first lumen 10 in a radial expansion configuration. In some embodiments, the second internal prosthesis 200 and / or expandable framework may be configured to extend beyond an opening to an adjacent lumen (e.g., a second lumen 20). In other words, the second internal prosthesis 200 may be configured to extend beyond the bifurcation 12 such that a first end region of the second internal prosthesis 200 is located in the first lumen 10 upstream of the bifurcation 12 (e.g., beyond the constriction 14), and a second end region of the second internal prosthesis 200 is located in the first lumen 10 downstream of the bifurcation 12.

[0058] In some embodiments, when the second implantable prosthesis 200 is arranged in a radially expanding manner within a plurality of loops 130 and / or passages 150, the first end portion 110 of the first implantable prosthesis 100 may extend laterally from the second implantable prosthesis 200 with respect to the central longitudinal axis of the second implantable prosthesis 200. In some embodiments, when the second implantable prosthesis 200 is arranged in a radially expanding manner within a plurality of loops 130 and / or passages 150 (the second implantable prosthesis 200 may be arranged in a first body lumen 20 downstream of the bifurcation 12), the first end portion 110 of the first implantable prosthesis 100 may extend away from the second implantable prosthesis 200 into the second body lumen 20.

[0059] In some embodiments, when the second internal prosthesis 200 is positioned in a radially expanding manner within a plurality of loops 130 and / or passages 150 (which may be positioned within the first body lumen 20 downstream of the branch 12), the second end portion 112 of the first internal prosthesis 100 may extend away from the second internal prosthesis 200 substantially parallel to the central longitudinal axis of the second internal prosthesis 200. In some embodiments, when the second internal prosthesis 200 is positioned in a radially expanding manner within a plurality of loops 130 and / or passages 150, the second end portion 112 of the first internal prosthesis 100 may extend away from the second internal prosthesis 200 within the first body lumen 10.

[0060] In some embodiments, the second internal prosthesis 200 may have an outer diameter and / or outward spread in a radially expanding form. In some embodiments, the outer diameter and / or outward spread of the second internal prosthesis 200 may be within about 20% of the inner diameter 132 of the passage 150. In some embodiments, the outer diameter and / or outward spread of the second internal prosthesis 200 may be within about 15% of the inner diameter 132 of the passage 150. In some embodiments, the outer diameter and / or outward spread of the second internal prosthesis 200 may be within about 10% of the inner diameter 132 of the passage 150. In some embodiments, the outer diameter and / or outward spread of the second internal prosthesis 200 may be within about 5% of the inner diameter 132 of the passage 150. In some embodiments, the outer diameter and / or outward spread of the second internal prosthesis 200 may be substantially the same as the inner diameter 132 of the passage 150.

[0061] In some embodiments, a portion of the second internal prosthesis 200 extending between adjacent loops of a plurality of loops 130 (when radially extended within the plurality of loops 130 of the first internal prosthesis 100) may have a second outer diameter and / or second outward spread that is greater than the outer diameter and / or outward spread of the second internal prosthesis 200 positioned within the passage 150 and / or plurality of loops 130, such that a portion of the second internal prosthesis 200 extends radially outward between adjacent loops 130.

[0062] In some embodiments, the second internal prosthesis 200 and / or expandable framework may include a polymer cover 220 positioned on and covering at least a portion of its length, and / or extending along at least a portion of its length. In some embodiments, the polymer cover 220 may be positioned on and / or along a first flared portion, a second flared portion, and / or a body portion extending between the first and second flared portions. In some embodiments, the polymer cover 220 may be positioned on and / or along the outer surface of the expandable framework. In some embodiments, at least a portion of the expandable framework may be embedded in the polymer cover 220. In some embodiments, the polymer cover 220 may be fixed, bonded, or otherwise attached to the expandable framework, either permanently or releasably. In some embodiments, the polymer cover 220 may be impermeable to fluids, debris, medical devices, etc. Some suitable but non-limiting materials for the polymer cover 220 are described below.

[0063] In some embodiments, the polymer cover 220 may extend along the entire length and / or outer circumference of the second implantable prosthesis 200 and / or expandable framework. In some embodiments, the polymer cover 220 may extend along a portion of the length of the second implantable prosthesis 200 and / or expandable framework. In some embodiments, the polymer cover 220 may be discontinuous. In some embodiments, in a radially expanding configuration, the polymer cover 220 may extend discontinuously between a first end (e.g., proximal end) and a second end (e.g., distal end) of the second implantable prosthesis 200 and / or expandable framework. In some embodiments, in a radially expanding configuration, the polymer cover 220 may extend continuously from the first end (e.g., proximal end) to the second end (e.g., distal end) of the second implantable prosthesis 200 and / or expandable framework. Other configurations are also being considered.

[0064] After deploying the second internal prosthesis 200 into a plurality of loops 130 and / or passages 150, the second internal prosthesis 200 and the polymer cover 220 (if present) can cooperate with the first internal prosthesis 100 to form a helical fluid pathway around the second internal prosthesis 200 (e.g., on its outside) from the second body lumen 20 to the lower part of the first body lumen 10. In at least some embodiments, the first internal prosthesis 100 can form a gap 30 between the outside (e.g., outer surface) of the second internal prosthesis 200 and the wall of the first body lumen 10, and the gap 30 can form a helical fluid pathway around the outside (e.g., outer surface) of the second internal prosthesis 200.

[0065] In some embodiments, the first internal prosthesis 100 may be configured to provide an internal drainage channel from the second body lumen 20 to the first body lumen 10, and / or through the lumen 102 of the first internal prosthesis 100. In some embodiments, the first internal prosthesis 100 may cooperate with the second internal prosthesis 200 and the polymer cover 220 (if present) to provide an external drainage channel from the second body lumen 20 to the first body lumen 10 along and / or using a helical fluid path around the outside of the second internal prosthesis 200. In some embodiments, the first internal prosthesis 100 may be configured to provide a drainage channel from the second body lumen 20 to the first body lumen 10 both internally (e.g., through the lumen 102 of the first internal prosthesis 100) and externally (e.g., along the outside of the first internal prosthesis 100 forming a gap 30 along the outside of the second internal prosthesis 200).

[0066] Figure 6 shows selected embodiments of alternative configurations for the first implantable prosthesis 100. In some embodiments, the first implantable prosthesis 100 may include a flexible region, such as a corrugated portion 160, located between the first end 104 and a plurality of loops 130. The flexible region (e.g., the corrugated portion 160) may be more flexible than the rest of the length of the first implantable prosthesis 100, including portions of the tubular member of the first implantable prosthesis 100 on either side of the flexible region. In some embodiments, the first end portion 110 may include the corrugated portion 160. In some embodiments, the corrugated portion 160 may separate the first end portion 110 into a first portion 162 and a second portion 164, with the flexible region (e.g., the corrugated portion 160) located between the first portion 162 and the second portion 164. In some embodiments, the first portion 162 may be located proximal to the flexible portion or corrugated portion 160 and / or between the flexible portion or corrugated portion 160 and the plurality of loops 130, and the second portion 164 may be located distal to the flexible portion or corrugated portion 160 and / or between the flexible portion or corrugated portion 160 and the first end 104.

[0067] In some embodiments, the corrugated portion 160 may be analogous to an accordion and / or bellows. The corrugated portion 160 may add an additional aspect of flexibility and / or bendability to the first end portion 110 of the first internal prosthesis 100. In some embodiments, the first internal prosthesis 100 having the corrugated portion 160 may be configured to easily conform to the irregular nature of a winding anatomical structure. In some embodiments, the corrugated portion 160 may be configured to bend and / or deflect the second portion 164 relative to the first portion 162. In other words, the central longitudinal axis of the second portion 164 may extend at an angle (e.g., acute, right, or obtuse) nonparallel to the central longitudinal axis of the first portion 162. In some embodiments, the second portion 164 may bend and / or deflect on the same plane as the first portion 162. In some embodiments, the second portion 164 may be bent and / or deflected obliquely and / or non-coplanar with respect to the first portion 162. Other configurations are also contemplated.

[0068] In some embodiments, the corrugated portion 160 may be manipulated by a guidewire 90 during delivery of the first implantable prosthesis 100. In some embodiments, the corrugated portion 160 may be maneuverable using one or more mechanisms incorporated into the first implantable prosthesis 100. For example, one or more maneuvering wires may be located within the first implantable prosthesis 100 and / or extend along the walls of the first implantable prosthesis 100. Other configurations are also conceivable.

[0069] Figure 7 illustrates selected alternative uses and / or configurations of the systems and / or methods for maintaining the patency of a body lumen disclosed herein. In some embodiments, the method may include the step of advancing a guidewire into the first body lumen 10 such that the guidewire extends upstream of the bifurcation 12. The method may include the step of advancing the first internal prosthesis 100 in a linear configuration on the guidewire into the first body lumen 10 such that the distal end region of the first internal prosthesis 100 is positioned in the first body lumen 10 upstream of the bifurcation 12 and the proximal end region of the first internal prosthesis 100 is positioned in the first body lumen 10 downstream of the bifurcation 12. In some embodiments, the first internal prosthesis 100 may be constrained into a linear shape by a guidewire when advancing it through the first body lumen 10 beyond the bifurcation 12. In some alternative embodiments, the first internal prosthesis 100 may be constrained into a linear shape by a delivery sheath surrounding it when advancing it through the first body lumen 10 beyond the bifurcation 12. Other configurations, including combinations thereof, are also conceivable. In some embodiments, advancing the first internal prosthesis 100 linearly into the first body lumen 10 may include positioning the first end portion 110 of the first internal prosthesis 100 in the first body lumen 10 upstream of the bifurcation 12, and positioning the second end portion 112 of the first internal prosthesis 100 in the first body lumen 10 downstream of the bifurcation 12, such that the intermediate region of the first internal prosthesis 100 spans the bifurcation 12.

[0070] The method may include the step of unfolding the first internal prosthesis 100 into a helical shape that forms multiple loops 130 within the first internal lumen 10, with the first end portion 110 of the first internal prosthesis 100 located in the first body lumen 10 on the first side of the bifurcation 12, such as upstream of the bifurcation 12, and the second end portion 112 of the first internal prosthesis 100 located in the first body lumen 10 on the second side of the bifurcation 12, such as downstream of the bifurcation 12. Thus, the middle portion of the first internal prosthesis 100 may be located at the bifurcation 12 when unfolded into a helical shape. When unfolded into a helical shape, the middle portion of the first internal prosthesis 100 may form multiple helical loops 130. The first internal prosthesis 100 may be configured to automatically transition from a linear configuration (where the helical loop 130 is straightened or elongated) when constrained by the guidewire 90 (or the outer sheath, if an outer sheath is present) to a helical configuration when unconstrained. In at least some embodiments, the first internal prosthesis 100 may be self-biased toward a helical configuration when unconstrained.

[0071] In some embodiments, at least a portion of the first implantable prosthesis 100 may extend away from the helical loops 130. In some embodiments, a first end portion 110 may extend away from the helical loops 130. In some embodiments, the first end portion 110 may extend from the loops 130 to the first end 104 of the first implantable prosthesis 100. In some embodiments, a second end portion 112 may extend away from the loops 130 in a helical shape. In some embodiments, the second end portion 112 may extend from the loops 130 to the second end 106 of the first implantable prosthesis 100.

[0072] Once the first internal prosthesis 100 has been delivered beyond the bifurcation 12 and expanded into a helical shape, the method may include the step of advancing a second guidewire into the first body lumen 10. After the first internal prosthesis has been expanded into a helical shape, the method may further include the step of advancing the second guidewire into and / or through the helical loops 130 and / or through the passage 150 of the first internal prosthesis 100. The method may further include the step of advancing the second internal prosthesis 200 into the first body lumen 10 in a radially contracting shape along the second guidewire. Accordingly, the second internal prosthesis 200 may be positioned within the helical loop 130 in a radially constrained or contracted manner, such that the helical loop 130 surrounds the second internal prosthesis 200, which is radially constrained or contracted, in which case the second internal prosthesis 200 extends from a portion of the first body lumen 10 proximal to (e.g., downstream of) the bifurcation 12 to a portion of the first body lumen 10 distal to (e.g., upstream of) the bifurcation 12. The second internal prosthesis 200 may be positioned such that its distal end region extends distal to the bifurcation 12 in a radially constrained or contracted manner, and its proximal end region extends proximal to the bifurcation 12 in a radially constrained or contracted manner.

[0073] The second internal prosthesis 200 may be configured to transition from a radially contracted form to a radially expanded form. In at least some embodiments, the second internal prosthesis 200 may be self-biased toward the radially expanded form. In some embodiments, the second internal prosthesis 200 may be formed from a superelastic material such as nitinol and / or a shape memory material. In some embodiments, the second internal prosthesis 200 may be constrained to the radially contracted form by the properties of the shape memory material when the second internal prosthesis 200 is advanced into the first body lumen 10. In some embodiments, the second internal prosthesis 200 may be constrained to the radially contracted form by a delivery sheath surrounding the second internal prosthesis 200 when the second internal prosthesis 200 is advanced into the first body lumen 10. Other configurations, including combinations thereof, are also conceivable.

[0074] In some embodiments, the delivery sheath may be a long catheter or other tubular member suitable for delivering an internal prosthesis and / or known in the art for delivering an internal prosthesis. The second internal prosthesis 200 may be positioned within the lumen of the delivery sheath in a radially constrained or contracted configuration. In the radially contracted configuration, the expandable framework may be stretched substantially linearly and / or completely. The second internal prosthesis 200 may be deployed from the delivery sheath by using one or more known techniques, such as withdrawing the delivery sheath proximal to the second internal prosthesis 200 to discharge the second internal prosthesis 200 from the delivery sheath. Other commonly known techniques, but not described for brevity, may be used to deploy the second internal prosthesis 200 from the delivery sheath.

[0075] The method may include the step of transitioning the second internal prosthesis 200 to a radially expanding form within a plurality of loops 130 and / or passages 150, as shown in Figure 7. In some embodiments, transitioning the second internal prosthesis 200 to a radially expanding form may include drawing out and / or retracting the delivery sheath relative to the second internal prosthesis 200 to expose the second internal prosthesis 200 within the first body lumen 10 and / or within the plurality of loops 130 and / or passages 150, thereby allowing the second internal prosthesis 200 to expand radially.

[0076] In at least some embodiments, the second internal prosthesis 200 and / or expandable framework may be deployed within the first body lumen 10 extending through a stenosis in order to maintain and / or re-establish the patency of the body lumen 10. In some embodiments, the second internal prosthesis 200 and / or expandable framework may be configured to expand at least a portion of the first body lumen 10 in a radial expansion configuration. For example, the second internal prosthesis 200 and / or expandable framework may be configured to exert a radially outward force against the wall of the first body lumen 10 and / or against a stenosis formed within the first body lumen 10.

[0077] In some embodiments, at least a portion of the second implantable prosthesis 200 may be positioned within a plurality of loops 130 and / or passages 150 in a radially expanding configuration. In some embodiments, when the second implantable prosthesis 200 is positioned within a plurality of loops 130 and / or passages 150 in a radially expanding configuration, at least a portion of the second implantable prosthesis 200 may extend away from the plurality of loops 130 and / or passages 150.

[0078] In some embodiments, the second internal prosthesis 200 may be configured to engage with a plurality of loops 130 and / or passages 150 in a radially expanding configuration. In the radially expanding configuration, the second internal prosthesis 200 may be configured to apply a radially outward force to the first internal prosthesis 100 and / or the plurality of loops 130 in a helical configuration, thereby engaging and / or pressing the first internal prosthesis 100 and / or the plurality of loops 130 against the wall of the first body lumen 10. In some examples, a portion of the second internal prosthesis 200 extending between adjacent loops 130 may extend radially outward and come into contact with the wall of the first body lumen 10.

[0079] In some embodiments, the second implantable prosthesis 200 may be configured to expand at least a portion of the first lumen 10 in a radial expansion configuration. For example, the second implantable prosthesis 200 may be configured to exert a radially outward force on the wall of the first lumen 10 in a radial expansion configuration. In some embodiments, the first implantable prosthesis 100 and the second implantable prosthesis 200 may be configured to extend beyond the opening to an adjacent lumen (e.g., a second lumen 20), as shown in Figure 7. In other words, the second implantable prosthesis 200 may be configured to extend beyond the bifurcation 12 such that a first end region of the second implantable prosthesis 200 is located in the first lumen 10 upstream of the bifurcation 12, and a second end region of the second implantable prosthesis 200 is located in the first lumen 10 downstream of the bifurcation 12.

[0080] In some embodiments, when the second implantable prosthesis 200 is arranged in a radially expanding configuration within a plurality of loops 130 and / or passages 150, the first end portion 110 of the first implantable prosthesis 100 may extend away from the second implantable prosthesis 200 substantially parallel to the central longitudinal axis of the second implantable prosthesis 200. In some embodiments, when the second implantable prosthesis 200 is arranged in a radially expanding configuration within a plurality of loops 130 and / or passages 150, the first end portion 110 of the first implantable prosthesis 100 may extend away from the second implantable prosthesis 200 within the first body lumen 10.

[0081] In some embodiments, when the second implantable prosthesis 200 is arranged in a radially expanding configuration within a plurality of loops 130 and / or passages 150, the second end portion 112 of the first implantable prosthesis 100 may extend away from the second implantable prosthesis 200 substantially parallel to the central longitudinal axis of the second implantable prosthesis 200. In some embodiments, when the second implantable prosthesis 200 is arranged in a radially expanding configuration within a plurality of loops 130 and / or passages 150, the second end portion 112 of the first implantable prosthesis 100 may extend away from the second implantable prosthesis 200 within the first body lumen 10.

[0082] In one example, when the second internal prosthesis 200 is arranged in a radially expanding manner within a plurality of loops 130 and / or passages 150, the first end portion 110 of the first internal prosthesis 100 may extend into the first body lumen 10 upstream from the second internal prosthesis 200, and when the second internal prosthesis 200 is arranged in a radially expanding manner within a plurality of loops 130 and / or passages 150, the second end portion 112 of the first internal prosthesis 100 may extend into the first body lumen 10 downstream from the second internal prosthesis 200. In another example, when the second internal prosthesis 200 is arranged in a radially expanding configuration within a plurality of loops 130 and / or passages 150, the first end portion 110 of the first internal prosthesis 100 may extend into the first body lumen 10 downstream from the second internal prosthesis 200, and when the second internal prosthesis 200 is arranged in a radially expanding configuration within a plurality of loops 130 and / or passages 150, the second end portion 112 of the first internal prosthesis 100 may extend into the first body lumen 10 upstream from the second internal prosthesis 200.

[0083] After deploying the second internal prosthesis 200 into a plurality of loops 130 and / or passages 150, the second internal prosthesis 200 and the polymer cover 220 (if present) can cooperate with the first internal prosthesis 100 to form a spiral fluid pathway around the second internal prosthesis 200 (e.g., on its outside) from the upper part (e.g., upstream) of the first body lumen 10 to the lower part (e.g., downstream) of the first body lumen 10, and from the second body lumen 20 to the lower part (e.g., downstream) of the first body lumen 10. In at least some embodiments, the first internal prosthesis 100 may form a gap 30 between the outside (e.g., outer surface) of the second internal prosthesis 200 and the wall of the first body lumen 10, and the gap 30 may form a spiral fluid pathway around the outside (e.g., outer surface) of the second internal prosthesis 200. The gap 30 may be fluidically accessible from the second body lumen 20, thereby maintaining fluid flow from the second body lumen 20 along the helical gap 30 within the first body lumen 10 when the first body lumen 10 is treated with the system.

[0084] In some embodiments, the first internal prosthesis 100, in cooperation with the second internal prosthesis 200 and the polymer cover 220 (if present), may externally provide a drainage channel from the second body lumen 20 to the first body lumen 10 along and / or using a helical fluid path around the outside of the second internal prosthesis 200. In some embodiments, the first internal prosthesis 100 may include a plurality of drainage ports 140 formed along the intermediate portion of the first internal prosthesis 100. The plurality of drainage ports 140 may be in fluid communication with the lumen 102 of the first internal prosthesis 100. The intermediate portion of the first internal prosthesis 100, including the plurality of drainage ports 140, may be positioned beyond the opening to the second body lumen 20. Multiple drainage ports 140 may allow fluid from the second body lumen 20 to access and / or flow into the lumen 102 of the first internal prosthesis 100. Thus, in some embodiments, the first internal prosthesis 100 may be configured to provide a drainage channel from the second body lumen 20 to the first body lumen 10 both internally and / or through the lumen 102 of the first internal prosthesis 100. In some embodiments, the first internal prosthesis 100 may be configured to provide a drainage channel from the second body lumen 20 to the first body lumen 10 both internally (e.g., through the lumen 102 of the first internal prosthesis 100) and externally (e.g., along the outside of the first internal prosthesis 100 forming a gap 30 along the outside of the second internal prosthesis 200).

[0085] Materials that may be used in the various components of the systems and their various elements disclosed herein include those generally associated with medical devices. For simplicity, the following description refers to systems. However, this is not intended to limit the devices and methods described herein, as this description may apply to other elements, members, components or devices disclosed herein, including, but not limited to, the first implantable prosthesis, the second implantable prosthesis, expandable frameworks, polymer covers, etc., and / or their elements or components.

[0086] In some embodiments, the stent system and / or its components may be made from metals, alloys, polymers (some examples of which are disclosed later), metal-polymer composites, ceramics, combinations thereof, etc., or other suitable materials.

[0087] Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylenetetrafluoroethylene (ETFE), fluoroethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN®), polyether block esters, polyurethane, polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., DSM Engineering Plastics (ARNITEL®), ether or ester copolymers (e.g., butylene / poly(alkylene ether) phthalate and / or other polyester elastomers such as HYTREL®), polyamides (e.g., DURETHAN® or CRISTAMID®), elastomer polyamides, block polyamides / ethers, polyether block amides (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, and polyethylene (PE). MARLEX high-density polyethylene, MARLEX low-density polyethylene, linear low-density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PP) O), poly(p-phenylene terephthalamide) (e.g., Kevlar®), polysulfone, nylon, nylon-12 (Grilamid®), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinyldenine chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS50A), polycarbonate, polyurethane silicone copolymer (e.g.,Examples include Elast-Eon® or ChronoSil®, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, and polymer / metal composites thereof. In some embodiments, the system and / or its components may be mixed with liquid crystal polymers (LCPs). For example, the mixture may contain up to approximately 6 percent LCP.

[0088] Some examples of suitable metals and alloys include stainless steels such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloys such as linear elastic and / or superelastic Nitinol; nickel-chromium-molybdenum alloys (e.g., UNS:N06625 such as Inconel® 625, UNS:N06022 such as Hastelloy® C-22, Hastelloy® C276, and other Hastelloy® alloys such as UNS:N10276); nickel-copper alloys (e.g., UNS:N04400 such as Monel® 400, Nickelvac® 400, Nicorros® 400); Other nickel alloys such as nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035, such as MP35-N®), nickel-molybdenum alloys (e.g., UNS:N10665, such as Hastelloy® Alloy B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as Elgiloy® and Phynox®); platinum-enriched stainless steel; titanium; platinum; palladium; gold; combinations thereof, etc.; or any other suitable material.

[0089] In at least some embodiments, some or all of the stent system and / or its components may be doped with, fabricated from, or otherwise incorporate radiopaque material. Radiopaque material is understood to be a material that can produce a relatively bright image on an X-ray fluoroscopy screen or another imaging technique (e.g., ultrasound) during a medical procedure. This relatively bright image helps the system user determine its location. Some examples of radiopaque material, but not limited to, include gold, platinum, palladium, tantalum, tungsten alloys, and polymer materials filled with radiopaque fillers. Furthermore, other radiopaque marker bands and / or coils may also be incorporated into the system design to achieve the same result.

[0090] In some embodiments, the systems and / or other elements disclosed herein are given a degree of magnetic resonance imaging (MRI) compatibility. For example, the systems and / or their components or parts may be made from materials that substantially do not distort images and do not produce substantial artifacts (e.g., gaps in the image). For example, certain ferromagnetic materials may be unsuitable because they can produce artifacts in MRI images. The systems or parts may also be made from materials that can be imaged by an MRI device. Some materials exhibiting these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003 such as ELGILOY® and PHYNOX®), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N®), and nitinol.

[0091] In some embodiments, the systems and / or other elements disclosed herein may include fabric materials placed on or within the structure. The fabric material may consist of biocompatible materials such as polymer materials or biomaterials adapted to promote internal tissue growth. In some embodiments, the fabric material may include bioabsorbable materials. Some examples of suitable fabric materials, but not limited to, include polyethylene glycol (PEG), nylon, polytetrafluoroethylene (PTFE, ePTFE), polyethylene, polyolefin materials such as polypropylene, polyester, polyurethane, and / or mixtures or combinations thereof.

[0092] In some embodiments, the systems and / or other elements disclosed herein include and / or may be formed from textile materials. Some examples of suitable textile materials include synthetic yarns that may be flat, molded, twisted, woven, shrink-proof, or unshrinkable. Suitable synthetic biocompatible yarns for use in this disclosure include, but are not limited to, polyesters including polyethylene terephthalate (PET) polyester, polypropylene, polyethylene, polyurethane, polyolefin, polyvinyl, polymethyl acetate, polyamide, naphthalene dicarboxylene derivatives, natural silk, and polytetrafluoroethylene. Furthermore, at least one of the synthetic yarns may be a metallic yarn, or a glass or ceramic yarn or fiber. Useful metallic yarns include yarns made from or containing stainless steel, platinum, gold, titanium, tantalum, or Ni-Co-Cr alloys. The yarns may further contain carbon, glass, or ceramic fibers. Preferably, the yarns are made from thermoplastic materials including, but are not limited to, polyester, polypropylene, polyethylene, polyurethane, polynaphthalene, polytetrafluoroethylene, etc. The sutures can be multifilamental, monofilamental, or spun type. The type and denier of the suture chosen may be selected to form a biocompatible and implantable prosthesis, more specifically, a vascular structure with desirable properties.

[0093] In some embodiments, the systems and / or other elements disclosed herein include and / or can be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents include antithrombotic agents (heparin, heparin derivatives, urokinase, and PPack (dextrophenylalanine proline arginine chloromethyl ketone), etc.); antiproliferative agents (enoxaparin, angiopeptin, monoclonal antibodies that can inhibit smooth muscle cell proliferation, hirudin, and acetylsalicylic acid, etc.); anti-inflammatory agents (dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, and mesalamine, etc.); antitumor / antiproliferative / antimitotic agents (paclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine, epotilon, endostatin, angiostatin, and thymidine kinase inhibitors, etc.); anesthetic agents (lidocaine, bupivacaine, and ropivacaine, etc.); anticoagulants (D-Phe-Pro-Arg chloromethyl ketone, RGD peptide-containing compounds, heparin); Examples of drugs include: antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, antiplatelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and mite-resistant antiplatelet peptides; vasodilators (growth factor inhibitors, growth factor receptor antagonists, transcription activators, and translation accelerators, etc.); vasodilators (growth factor inhibitors, growth factor receptor antagonists, transcription repressors, translation repressors, replication inhibitors, inhibitory antibodies, antibodies against growth factors, bifunctional molecules consisting of growth factors and cytotoxins, bifunctional molecules consisting of antibodies and cytotoxins); immunosuppressants (Olimus drugs, rapamycin analogs, macrolide antibiotics, biolimus, everolimus, zotarolimus, temsirolimus, picrolimus, novolimus, myolimus, tacrolimus, sirolimus, pimecrolimus, etc.); cholesterol-lowering drugs; vasodilators; and drugs that interfere with the intrinsic vasoactive mechanism.

[0094] This disclosure should be understood to be, in many respects, merely illustrative. Modifications may be made in detail, particularly with respect to the shape, size, and arrangement of steps, without exceeding the scope of this disclosure. This may include, to the appropriate extent, using any feature of one embodiment used in other embodiments. The scope of this disclosure is, of course, defined by the language in which the appended claims are expressed.

Claims

1. A system for maintaining the patency of the body lumen, A first internal prosthesis having a lumen extending from a first end to a second end, the first internal prosthesis being configured to transition from a linear form to a helical form forming multiple loops, A second internal prosthesis configured to transition from a radially contracting state to a radially expanding state, The aforementioned plurality of loops define passages having an inner diameter, A system in which at least a portion of the second internal prosthesis is arranged within the passage in the radially expanding form.

2. The system according to claim 1, wherein when the second internal prosthesis is positioned within the passage in the radially expanding manner, at least a portion of the second internal prosthesis extends away from the passage.

3. The system according to claim 1, wherein at least a portion of the first internal prosthesis extends away from the plurality of loops.

4. The system according to claim 3, wherein when the second internal prosthesis is positioned within the passage in the radially expanding manner, the first end portion of the first internal prosthesis extends laterally from the second internal prosthesis with respect to the central longitudinal axis of the second internal prosthesis.

5. The system according to claim 3, wherein when the second internal prosthesis is positioned within the passage in an expanded radial configuration, the second end portion of the first internal prosthesis extends away from the second internal prosthesis substantially parallel to the central longitudinal axis of the second internal prosthesis.

6. The second internal prosthesis has an outer diameter in the radially expanded form, The system according to claim 1, wherein the outer diameter of the second internal prosthesis is within 20% of the inner diameter of the passage.

7. The system according to any one of claims 1 to 6, wherein the plurality of loops define an outer diameter of 6 French to 12 French.

8. The system according to any one of claims 1 to 6, wherein the first internal prosthesis is self-biased toward the helical shape.

9. The system according to any one of claims 1 to 6, wherein the second internal prosthesis is self-biased toward the radially expanding form.

10. The system according to any one of claims 1 to 6, wherein the second internal prosthesis includes a polymer cover extending along at least a portion of the length of the second internal prosthesis.

11. The system according to any one of claims 1 to 6, wherein the first internal prosthesis includes a waveform portion positioned between the first end and the plurality of loops.

12. The system according to any one of claims 1 to 6, wherein the first internal prosthesis includes one or more drainage holes extending through the side wall of the first internal prosthesis.

13. The system according to any one of claims 1 to 6, wherein the first internal prosthesis includes one or more anti-movement elements extending radially outward from the first internal prosthesis.

14. The system according to any one of claims 1 to 6, wherein the first internal prosthesis is formed from a polymer material.

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