Shape-memory polymer foam that seals the space around the valve

Abstract

This concerns leakage involving the transplanted valve, whether it is a cardiac valve, peripheral venous valve, or other valve. [Solution] Regarding leakage around the valve, the gap around the heart valve, which may be improperly fixed, have an abnormal cross-section, or be insufficiently positioned relative to calcified lesions, is filled with individual SMP foam bodies (foam) that expand radially to fill the gap.

Description

Technical Field

[0004] ,

[0003] , , ,

[0001] Priority: This application claims priority to U.S. Provisional Patent Application No. 62 / 471,131, filed on March 14, 2017, with the title "Shape Memory Polymer Foams to Seal Space Around Valves", the content of which is incorporated herein by reference. Technical Field: The present invention relates to the field of medical devices, particularly valves.

Background Art

[0002] Surgery to replace a heart valve (e.g., aortic valve or mitral valve) is performed for various reasons such as stenosis or regurgitation of the mitral valve, aortic valve, pulmonary valve, or tricuspid valve. In this surgery, the damaged valve is removed and replaced with an artificial valve. Such valve replacement is usually an open-heart surgery. However, for patients, a minimally invasive surgery or a method of leaving a catheter instead of the valve is also an option. An artificial valve may be a machine (made of an artificial substance) or made of animal tissue.

Summary of the Invention

[0003] Paravalvular or paraprosthetic leak (PVL) is a complication associated with the implantation of an artificial heart valve by a conventional (surgical) approach or a transcatheter (TAVI) approach. Paravalvular or paraprosthetic leak refers to the leakage of blood through a channel between the structure of the implanted valve and the heart tissue as a result of inappropriate sealing. Many PVLs are crescent-shaped, elliptical or circular, and the trajectories are parallel, perpendicular or meandering. The incidence of PVL, including small small small but not limited to small, non-significant jets, is estimated to reach 20%. Also, PVL is more common in the mitral valve (up to 20%) than in the aortic valve. [[ID=​Features and advantages of embodiments of the present invention will become apparent from the appended claims, the detailed description of one or more exemplary embodiments below, and the corresponding drawings. Where appropriate, reference marks in the figures are repeated to indicate corresponding or similar elements. [Brief explanation of the drawing]

[0005] [Figure 1] One embodiment includes a shape memory polymer (SMP) foam that substantially covers the window of the stent.

[0006] [Figure 2] A shows a radially compressed SMP foam in one embodiment. B shows a radially expanded SMP foam.

[0007] [Figure 3] A shows a radially compressed SMP foam in one embodiment. B shows the radially compressed foam and stent after compression for delivery to the patient.

[0008] [Figure 4] This includes a radiation-opaque monolithic SMP foam ring in one embodiment. This also demonstrates the machinability for this embodiment (i.e., the ability to form the foam into various shapes and sizes).

[0009] [Figure 5] A shows a low-density foam matrix in one embodiment. B shows a high-density foam doped for radio-opacity.

[0010] [Figure 6] A shows an expanded SMP foam. B shows an SMP foam during compression. C shows an SMP foam during compression.

[0011] [Figure 7]Various shapes and sizes illustrating the machining capabilities of the embodiment are shown. [Modes for carrying out the invention]

[0012] Drawings are referenced here, where similar structures may be given the same reference numeral at the end. The drawings included herein are schematic and more clearly illustrate the structures of various embodiments. Therefore, the actual appearance of a manufactured structure in, for example, a photograph may look different, although it still incorporates the claimed structure of the illustrated embodiment. Furthermore, drawings may show only structures useful for understanding the illustrated embodiment. Further structures known in the art may be omitted to maintain clarity in the drawings. Terms such as “embodiment” and “various embodiments” refer to embodiments described, but not all embodiments necessarily include a particular feature, structure, or characteristic.

[0013] Some embodiments may have some or all of the features described in other embodiments. Terms such as “first,” “second,” and “third” describe common objects and also indicate different examples of similar objects being referenced. Such adjectives do not imply that the described objects are described in a given permutation or in a temporal, spatial, ranking or otherwise manner. The term “connected” may indicate that elements are in direct physical or electrical contact with one another, and “linked” may indicate that elements cooperate or interact with one another, but may or may not be in direct physical or electrical contact with one another.

[0014] Many of the embodiments described herein relate to perivalve leakage. However, these embodiments more generally relate to leakage involving the transplanted valve, whether it is a cardiac valve, a peripheral venous valve, or any other valve.

[0015] The applicant has attempted to fill the paravalvular cavity using conventionally used materials, such as PET (Dacron) "skirts," to promote tissue integration. However, the applicant has further found that this technique is not adequate for either volumetrically filling the perivalvular space or promoting tissue integration. Embodiments described herein use shape memory polymer (SMP) foam to fill the perivalvular space and promote tissue integration.

[0016] For example, one embodiment involves the use of SMP foam incorporated around the annulus of a heart valve to reduce flow around the valve and facilitate integration of the device into the surrounding tissue. More specifically, the SMP foam expands and fills gaps around the valve that may be improperly fixed, have abnormal cross-sections, or have insufficient apposition to calcified lesions. For example, radial expansion of the foam results in volumetric filling around the device. This is applicable to surgically implanted valves, where the foam's shape-memory properties are particularly useful for intravascular valve delivery.

[0017] Many of the embodiments described herein relate to radial compression (and subsequent radial expansion) of SMP foam, but other embodiments may use axial compression / expansion and / or circumferential compression / expansion.

[0018] Once implanted, the foam blocks leakage from around the valve, promotes tissue integration, and achieves sustained occlusion. The porous morphology of the foam promotes acute thrombus formation and device sealing. Over time, the thrombus is replaced by integrated tissue, resulting in sustainable sealing and integration of the device with surrounding tissue.

[0019] As one embodiment, there is a monolithic foam annulus adhered to the valve. For example, refer to the foam annulus in FIG. 4. As for the adhesion, intertwining the valve support struts through the foam (for example, refer to FIG. 1), adhering the valve support struts to the foam, and / or coating the valve support struts with a polymer (such as polyurethane) film, and adhering the foam to the polymer film can be mentioned. When the foam is attached to the valve support structure, it can surely prevent the foam from falling off or moving downstream to block the blood vessel.

[0020] As shown in FIG. 2B, as one embodiment, there is an independent foam "scale" adhered to the device.

[0021] In one embodiment, the nitinol wire is threaded through a polymer foam (refer to FIGS. 1 and 3A). After the wire structure is threaded through the foam, they are joined together to form a support structure.

[0022] In one embodiment, the bottom of the SMP "scale" is not coupled to the nitinol frame (refer to FIGS. 1, 3A, and 3B). As an embodiment of the foam "scale", anisotropic strain (for example, refer to FIG. 3B) is adjusted so that the valve support structure is received into the delivery catheter during radial compression. For example, each window of the support structure shrinks along the circumferential axis (for example, refer to the "horizontal" arrow in FIG. 3A showing the movement of the nitinol window), but elongates axially (for example, refer to the "vertical" arrow in FIG. A showing the movement of the nitinol window). In other words, the bottom of the scale is free and does not receive significant tension that could lead to the rupture of the foam.

[0023] In one embodiment, the SMP "scale" includes windows (refer to the upper void of the SMP foam in FIG. 1) for welding and connecting adjacent support struts.

[0024] Other scales include FIGS. 5A, 5B, 6A, 6B, 6C, and 7. The foam shape factors shown in FIGS. 5A - 7 indicate different degrees of areas filled within each "window" of the support structure. Changing the foam shape factor can vary the degree of radial compression and scale folding after compression. When a flat foam scale is radially compressed, it folds like a catheter balloon, minimizing the crimp cross-sectional area for proper placement during delivery.

[0025] Many of the above embodiments relate to the sealing of valves, particularly heart valves, but other embodiments are not limited thereto and may be, for example, the sealing of abdominal aortic aneurysm (AAA) stent grafts.

[0026] As one embodiment, there is a foam obtained by the reaction of one or more polyols (e.g., HPED and / or TEA) and one or more diisocyanates (e.g., hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), and / or isophorone diisocyanate) that form polyurethane SMP. As embodiments, there are polyurethane SMP foams synthesized by some combinations of HDI, TMHDI, isophorone diisocyanate, triethanolamine, diethanolamine, butanediol, butindiol, N, N,N’,N’-tetrakis(hydroxypropylene)ethylenediamine.

[0027] As another embodiment, there is an X-ray visible SMP foam. For example, as one embodiment, there is a foam obtained by the reaction of one or more polyols (e.g., 5-amino-2,4,6-triiodoisophthalic acid; 3-methyl-1,5-pentanediol; 2-butyl-2-ethyl-1,3-propanediol; hexanetriol; butanetriol) and one or more diisocyanates (e.g., HDI) that form polyurethane SMP.

[0028] The embodiments provide various means for reliably protecting the foam during transport of the device.

[0029] In one embodiment, the valve is delivered through a large-diameter catheter / sheath, which allows for large-scale delivery "ramrod" (which can adjust for significant friction from the inflation device) and the valve is deployed from the catheter / sheath. The foam is not sheared during delivery because it is bonded to the support structure (for example, the foam may be bonded to a support or locally bonded across the entire window).

[0030] In some transcatheter embodiments, the foam expansion is delayed. For example, the device may be stored at a temperature well below body temperature, and once it reaches body temperature (which may exceed the foam's wet Tg), it may be programmed to expand rapidly. The foam may be stored in its water-plasticized state.

[0031] (In contrast to transcatheter implantation) Surgical implantation may be performed with the foam at body temperature or higher.

[0032] In some embodiments (e.g., transcatheter or surgical implantation), the foam is expanded using warm saline solution at the end of preparation.

[0033] In cases where a foam is used instead of a conventional Dacron skirt, one embodiment involves the foam being contained within a lubricating sheath (e.g., a sheath made of PTFE), and the surgeon removes the sheath when the device is ready for deployment. This minimizes the shear force on the foam, considering, for example, that PTFE is more slippery / less resistant than many PU catheters.

[0034] Embodiments include low-density and / or high-density foams. In embodiments, density is used to balance the mechanical strength of the foam (for example, higher density reduces shear / tear resistance) by minimizing the compression diameter (for example, higher density reduces shear / tear resistance). One embodiment is a foam with a pore size of 50 to 1500 microns.

[0035] In some embodiments, the foam never expands into the main vessel. For example, the foam is sufficiently adhered to the support structure and expands radially outward from the lumen. A valve to which foam adheres must not damage the ventricle. For example, in one embodiment, mechanical restraints are used to prevent the foam from expanding radially inward into the main vessel. For example, a valve may prevent the foam from expanding inward. In another example, a polymer membrane placed between the foam and the inner channel of the device may prevent the foam from expanding inward.

[0036] Embodiments may include scales that are not all identical. For example, one embodiment may include a multi-row scale, some of which may be half-scales and others full-scales. The rows may be within two different scale patterns and / or have their scale sizes swapped.

[0037] In one embodiment, both a Dacron skirt and SMP foam are used. For example, the Dacron skirt acts like a "sheath" that folds over the crimped foam to facilitate delivery.

[0038] In multiple embodiments, the device can be used under different pressure environments (e.g., venous pressure versus arterial pressure). In these embodiments, different pore sizes / forming factors may be used.

[0039] In multiple embodiments, the device can also address leakage around the valve of venous valve replacement devices, such as those for the lower extremity vena cava.

[0040] Figure 1 shows a system 100 having a stent including first, second, third, and fourth struts 101, 102, 103, and 104. The stent further includes first, second, third, fourth, and fifth windows 111, 112, 113, 114, and 115. A valve 121 is contained within the stent (best seen in Figure 2B). An open-cell polyurethane thermosetting SMP foam 131 is configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation, and the outer conduit contains the stent. In Figure 1, the first and third windows 111, 113 share the first strut 101 and are both directly adjacent to the first strut. The second and third windows 112, 113 share the second strut 102 and are both directly adjacent to the second strut. The fourth and third windows 113, 113 share the third strut 103 and are both directly adjacent to the third strut. The fifth and third windows 115 and 113 share the fourth support 104 and are both directly adjacent to the fourth support. The supports 101 and 103 may be contained within a single monolithic length wire, which constitutes other “supports,” but the term “support” as used herein refers to the “support.”

[0041] In Figure 1, the SMP foam 131 substantially covers at least 80% of the first surface of the third window. This "surface" is perhaps 95% (or more) obscured in the embodiment of Figure 1, and the surface is mainly formed by the supports 101, 102, 103, and 104.

[0042] In one embodiment, the first, second, third, and fourth supports may each be made of a shape-memory metal such as nitinol. However, other embodiments are not limited to this and may include stainless steel or other metals. The shape-less memory metal may be deployed by a balloon or other inflatable device. Another embodiment is a surgical implant valve.

[0043] In Figure 1, the first and second supports 101 and 102 are fixedly connected to the SMP foam, while the third and fourth supports 103 and 104 are not fixedly connected to the SMP foam. The applicability of this arrangement is extended as follows: The foam 131 may be in contact with the support 103, but is not "fixed" to the support 103, and if the support 103 deforms due to the extension of the stent, the foam 131 will not necessarily move with the support. However, the foam 131 is fixed to the support 101 and moves with the movement of the support 101. In other words, the movement of the foam 131 depends on the support 101 and not on the support 103.

[0044] In the first direction (for example, when the system is packaged for shipment to a medical facility), the outer diameter of the stent is the first maximum stent outer diameter. As shown in Figure 3B, the length of window 313 (similar to window 113 in Figure 1) is the first window length 341, measured parallel to the long axis 341 of the stent. The window is also perpendicular to the long axis of the stent, and the length of this window is the first window width 342', measured parallel to the short axis 343 of the stent. The SMP foam 331 is in a compressed secondary state.

[0045] In the second direction, the outer diameter of the stent is the second maximum stent outer diameter 342, which is longer than the first maximum stent outer diameter 342'. This is because the stent is compressed (possibly folded) by the stent (which is ready for implantation), reducing the stent's trajectory. In this case, the stent may be extended along axis 341 and undergo necking (stenosis) along axis 343. As a result, the window length of window 313 is the second window length 340, which is shorter than the first window length 340'. Also, the width of window 313 is the second window width 342, which is wider than the first window width 342'. The SMP foam is in its expanded primary state in the second direction.

[0046] In contrast to the change in the length of the window 313, the body length of the SMP foam 331 is the same in the compressed and expanded states (at least in some embodiments). For example, length 344' is substantially the same as length 344' (+ / 3%). In some embodiments, the width of the foam may be the same in the compressed and expanded states (although the width appears to change in Figures 3A and 3B, in some embodiments the width of the foam does not change). Consistency in the length and width of the foam is considered before folding or folds occur in the system. In some embodiments, the foam 331 is compressed only radially (into the page of Figure 3A) and is little to no compression / expansion in the axial direction (along axis 341) or circumferential direction (generally along axis 343).

[0047] The applicant noted that such "crimping dynamics" exist and that the problem of the metal stent being able to deform more than the SMP foam (i.e., axially) is important. Furthermore, the applicant noted that metals such as nitinol have relatively low strain capacity (e.g., 4%), while SMP foam has relatively high strain capacity. That is, if the metal stent deforms significantly axially (along axis 341), the deformation can be greater than the axial deformation of the SMP foam. For example, the SMP foam may have little to no axial deformation. Therefore, the radially compressed SMP foam cannot deform to the extent of the metal window length difference of 340'' (340''-340=340''). In various embodiments, the axial extension of the foam can be 0, 5, 10, 15, or 20% of the axial difference of 340''.

[0048] In response to the compression dynamics, one embodiment fixes the foam 331 to some of the stent's struts but not to others. For example, in Figure 1, the SMP foam 131 fixes and connects struts 101 and 102 at positions 151, 151' and 152, 152'. At positions 151, 151' and 152, 152', struts 101 and 102 repeatedly penetrate the SMP foam 131, fixing the foam 131 to the stent. In other words, strut 101 penetrates the SMP foam 131 at least at one position (e.g., position 151), and as a result, the first strut traverses from the first surface of the SMP foam (front in Figure 1) to the second surface of the SMP foam (rear surface not visible in Figure 1), with the first and second surfaces facing each other. Note that the lower half of the SMT foam 131 is not fixedly attached to the supports 103 and 104. In response to the first and second supports 101 and 102 fixedly connected to the SMP foam 131 and the third and fourth supports 103 and 104 which are not fixedly connected to the SMP foam, the SMP foam is configured to move in accordance with the first and second supports and independently of the third and fourth supports when the device moves from the first direction to the second direction. For example, in Figures 3A and 3B, the foam 331 will move up and down (or up and down along the axis 341) when the supports 301 and 302 move up and down along the axis 341. However, extreme downward deflection by the supports 303 and 304 will not damage or break the cells of the SMT foam 331 because the foam is largely independent of the movement of the supports 303 and 304.

[0049] Regarding the connection of the foam 131 to various supports, the SMT foam can also be connected to the stent by other means. For example, in one embodiment, an adhesive (e.g., a UV epoxy weld using Dymax 203A-CTH-F to connect the nitinol supports to the polyurethane of the SMP foam) connects the SMP foam 131 to the first and second supports 101 and 102. The adhesive may be applied along lengths 161 and 162, but not along lengths 161' and 162', nor on supports 103 and 104. The adhesive is not visible in Figure 1 because it is between the foam 131 and the supports. Masking may be used in areas 161', 162', 103, and 104 to ensure that the adhesive is not applied to these areas. The masking (e.g., oxide or nitride) may be removed later in the process in some embodiments.

[0050] In one embodiment, the adhesive is an unfoamed polyurethane coating that is in direct contact with the first support column 101 and fixed to it. The SMP foam 131 is in direct contact with the polyurethane coating and is fixedly bonded to the polyurethane coating. As a result, the polyurethane coating fixes and bonds the SMP foam 131 to the first support column 101. Therefore, when the polyurethane foam is bonded to other polyurethane, the bond between the adhesive and the foam becomes stronger. For example, neat polyurethane can be used as the unfoamed polyurethane coating.

[0051] In one embodiment, the polyurethane coating is a curable thermosetting resin. However, in other embodiments, the polyurethane coating is thermoplastic. According to one embodiment, the chemical composition of the polyurethane coating is the same as that of the SMP foam. Therefore, the adhesion between the foam and the adhesive is "like to like" and thus reliable. For example, both the SMP foam and the adhesive coating can be obtained from a reaction between one or more polyols (e.g., HPED and / or TEA) and one or more diisocyanates (e.g., hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), and / or isophorone diisocyanate).

[0052] In one embodiment, the polyurethane coating is SMP. The chemical composition of the SMP coating may be the same as the chemical composition of the SMP foam. In one embodiment, the SMP coating foams to produce a first foam (inner foam) that connects a second foam (outer foam 131) to the stent support.

[0053] Furthermore, regarding the composition of the foam 131, in one embodiment, the SMP foam is covalently bonded with iodine to form a foam that is visible under X-ray imaging (i.e., radiation opacity). Also, regarding radiation opacity, in one embodiment, the SMP foam is poly(urethane-urea-amide). In one embodiment, triiodobenzene monomer is used as the iodine.

[0054] As described above, in the compressed state, the foam 131 is compressed radially along a radius 155 that is perpendicular to both the long axis 141 and the short axis 143 of the stent. This is better observed in Figures 2A (compression) and 2B (radial expansion).

[0055] In various embodiments, one or more foam segments are used in various ways.

[0056] For example, in Figure 1, the SMP foam 131 substantially covers most of the surface of window 113, but does not cover most of any of the surfaces of the first, second, fourth, and fifth windows 111, 112, 114, and 115. In the embodiment of Figure 1, window 113 is directly adjacent to each of the first, second, fourth, and fifth windows 111, 112, 114, and 115. There are no other stent windows between window 114 and any of the windows 111, 112, 114, and 115.

[0057] For example, Figure 2A discloses an SMP foam 131. Furthermore, Figure 2A includes a further open-cell polyurethane thermosetting SMP foam 132, which is configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation. The foam 132 substantially covers the first surface of the fourth window 215, which has a first surface and a second surface facing each other. At least a portion of the fourth column 104 fixes the further SMP foam 132 (but not the foam 131). In the first direction, the further SMP foam is in a compressed secondary state, and in the second direction, the further SMP foam is in an expanded primary state.

[0058] In one embodiment, the foam 131 may be slightly enlarged so that it extends into the boundary 131'. As a result, the enlarged SMP foam 131 and the further SMP foam 132 overlap each other (see region 133 for the overlapping region), and their axes (see dot 155' indicating the axis toward the page) intersect both the SMP foam 131 and the further SMP foam 132. The axis 155' is perpendicular to the long axis 141 and the short axis 143 of the stent.

[0059] As observed in Figure 2A, the SMP foam 131 has a first surface region. The further foam 132 has a second surface region. The first surface region is at least 20% larger than the second surface region. However, in other embodiments, one foam segment may have a surface region that is 30, 40, 50, 60, 70, 80, or 90% or more larger than that of the other foam segments.

[0060] In the embodiment of Figure 2B, foam 131 coexists with foam 135. Further open-cell polyurethane thermosetting SMP foam 135 is configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation. The further SMP foam 135 substantially covers the first face of the sixth window 216 contained in the stent, which has a first and second face facing each other. The other SMP foam 135 does not substantially cover the third window 113. SMP foam 131 does not substantially cover the sixth window 216. Further struts 201 are contained in the sixth window 216 and fixatively connect the further SMP foam 135 (similar to how struts 101 connect foam 131). In the first direction, the further SMP foam 135 is in a compressed secondary state, and in the second direction, the further SMP foam is in an expanded primary state.

[0061] Also, in Figure 1, the first plane 157, parallel to the stent's minor axis 143, intersects with the SMP foam 131, the first and second supports 101 and 102, and the first, second and third windows 111, 112, and 113. The second plane 158, parallel to the stent's minor axis, intersects with the SMP foam 131, the third and fourth supports 103 and 104, and the third, fourth and fifth windows 113, 114, and 115. The first plane 157 does not intersect with either of the third and fourth supports 103 and 104. The first plane 157 does not intersect with either of the fourth and fifth windows 114 and 115. The second plane 158 does not intersect with either of the first and second supports 101 and 102. The second plane 158 does not intersect with either of the first windows 111 and 112.

[0062] In the embodiment shown in Figure 1, the first support 101 connects the second support 102 at the first joint 108. The axis 109 (see dot on page) intersects the first joint but does not come into contact with the SMP foam 131. The axis 109 is perpendicular to the long axis 141 and the short axis 143 of the stent. As described above, the support 101 may be "mounted" via the foam 131, after which the supports 101 and 102 are connected to each other (e.g., welded). Thus, windows or gaps with side walls 107, 107' may be formed such that the connection (e.g., welding) occurs without interference from the existing foam 131.

[0063] Regarding the "outer conduit" described above, embodiments may use a conduit (e.g., tube, sheath, skirt, catheter) to deploy the foam / stent system. In one embodiment, the outer conduit may be polytetrafluoroethylene (PTFE), extruded PTFE (ePTFE), or other relatively low-friction material that limits the shear force in the SMP foam.

[0064] In some embodiments, other conduits may be provided in addition to or instead of the “outer conduit” described above. For example, in one embodiment, an inner conduit (such as a polyurethane membrane) may be provided between the valve and the SMP foam. For example, a Dacron skirt (or any various polymer skirt / conduit in various embodiments, such as a polyurethane skirt) may be present between the valve and the stent and may function to ensure that the SMP foam does not expand in the main vessel (e.g., the aorta). In other embodiments, the inner conduit may be between the stent and the SMP foam. An adhesive may connect the foam to the inner conduit. The inner conduit may be connected to a strut. Thus, the foam is connected to the strut via the adhesive and the inner conduit. In one embodiment, an unfoamed SMP adhesive adheres the SMP foam (having the same chemical composition as the adhesive) to a non-shape memory inner conduit (e.g., a polyurethane inner conduit) connected to the stent.

[0065] As shown in Figure 4, one embodiment includes an SMP foam containing a monolithic SMP foam ring. The SMP foam ring is located outside the stent and may surround it. The ring may have folds or pleats that control the ring and promote repeatable collapse when the stent is folded to minimize the implantation profile. The upper half of the ring may be fixed to a support, but the lower half of the ring does not need to be fixed to a support, thereby preventing excessive stretching of the lower half when the stent is stretched axially. The embodiment in Figure 4 is small and may be suitable for peripheral blood vessels (e.g., venous valves), but other embodiments may be larger to surround heart valves, etc.

[0066] The following examples relate to further embodiments.

[0067] Example 1: A device comprising (a)(i) a stent including first, second, third, and fourth supports and (a)(ii) first, second, third, fourth, and fifth windows; a valve contained within the stent; a foamed polyurethane thermosetting shape memory polymer (SMP) foam, the SMP foam being configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation; and an outer conduit, wherein (b)(i (b)(ii) The first and third windows share the first support and are both directly adjacent to the first support; (b)(iii) The fourth and third windows share the third support and are both directly adjacent to the third support; (b)(iv) The fifth and third windows share the fourth support and are directly adjacent to the fourth support; the third window has a first and second surface facing each other, and the SMP foam is as (c)(i) the first and second supports fix and connect the SMP foam, but (c)(ii) the third and fourth supports do not fix and connect the SMP foam; in the first direction, (d)(i) the stent has the maximum outer diameter of the first stent, (d)(ii) the third window has the length of the first window measured parallel to the long axis of the stent, and (d)(iii) the third window is measured perpendicular to the long axis of the stent, and the stent (d)(iv) the SMP foam is in a compressed secondary state, and (e)(i) the stent has a second maximum stent outer diameter that is longer than the first maximum stent outer diameter, (e)(ii) the third window has a second window length that is shorter than the length of the first window, (e)(iii) the third window has a second window width that is wider than the width of the first window, and (e)(iv) the SMP foam is in the expanded primary state;Furthermore, the device is configured such that, depending on the first and second support columns that fix the SMP foam to each other and the third and fourth support columns that do not fix it to each other, when the device moves from the first direction to the second direction, the SMP foam moves depending on the first and second support columns but not on the third and fourth support columns.

[0068] In other embodiments, the SMP foam covers substantially at least 50, 60, 70, or 90% of the first surface of the third window.

[0069] In another embodiment of Example 1, the apparatus comprises (a)(i) a stent including first, second, third, and fourth supports and (a)(ii) first, second, third, fourth, and fifth windows; a valve contained within the stent; a foamed polyurethane thermosetting shape memory polymer (SMP) foam, the SMP foam being configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation; and an outer conduit, wherein (b)(i) the (b)(ii) The first and third windows share the first support and are both directly adjacent to the first support; (b)(iii) The fourth and third windows share the third support and are both directly adjacent to the third support; (b)(iv) The fifth and third windows share the fourth support and are directly adjacent to the fourth support; the third window has a first and second surface facing each other, and the SMP foam covers substantially less of the first surface of the third window. (c)(i) the first and second supports fix and connect the SMP foam, but (c)(ii) the third and fourth supports do not fix and connect the SMP foam; in the first direction, (d)(i) the stent has the maximum outer diameter of the first stent, (d)(ii) the third window has the length of the first window measured parallel to the long axis of the stent, and (d)(iii) the third window is measured perpendicular to the long axis of the stent. (d)(iv) the SMP foam is in a compressed secondary state; in the second direction, (e)(i) the outer diameter of the stent has a second maximum outer diameter that is longer than the first maximum outer diameter of the stent, (e)(ii) the third window has a second window length that is shorter than the length of the first window, (e)(iii) the third window has a second window width that is wider than the width of the first window, and (e)(iv) the SMP foam is in the expanded primary state;Furthermore, the device is configured such that, depending on the first and second support columns that fix the SMP foam to each other and the third and fourth support columns that do not fix it to each other, when the device moves from the first direction to the second direction, the SMP foam moves depending on the first and second support columns but not on the third and fourth support columns.

[0070] In another embodiment of Example 1, the apparatus includes: (a)(i) a stent having first, second, third, and fourth supports and (a)(ii) first, second, third, fourth, and fifth windows; a valve contained within the stent; and an open-cell polyurethane thermosetting shape memory polymer (SMP) foam, the SMP foam having already been expanded from a compressed secondary state to an expanded primary state; and an outer conduit containing the stent, wherein (b)(i) the first and third windows share the first support and are both directly adjacent to the first support; (b)(ii) the second and third windows share the second support and are both directly adjacent to the second support; (b)(iii) the fourth and third windows share the third support and are both directly adjacent to the third support; (b)(iv) the fifth and third windows share the fourth support and are directly adjacent to the fourth support; and the third window has a first and second face facing each other. (c)(i) the SMP foam covers substantially at least 80% of the first surface of the third window; (c)(ii) the first and second supports fix and connect the SMP foam, but (c)(ii) the third and fourth supports do not fix and connect the SMP foam; in the first direction, (d)(i) the stent has a first maximum outer diameter of the stent; (d)(ii) the third window has the length of the first window measured parallel to the long axis of the stent; (d)(iii) the third window has the width of the first window measured perpendicular to the long axis of the stent and parallel to the short axis of the stent; in the second direction, (e)(i) the stent has a second maximum outer diameter of the stent that is longer than the first maximum outer diameter; (e)(ii) the third window has the length of the second window that is shorter than the length of the first window; (e)(iii) the third window has the width of the second window that is wider than the width of the first window.

[0071] Therefore, in some embodiments, the product may be shipped with the SMP foam already transitioned from a compressed state to an uncompressed state (e.g., already plasticized).

[0072] While windows and supports are dealt with in some embodiments discussed herein, the embodiments are not limited to any one form of support structure. Metal or polymer support skeletons are viable options that benefit from SMP foam in reducing or preventing PVL. Furthermore, the lower half of the SMP foam may be bonded to the support structure, while the upper half may not. This allows for the extension of the support structure (for example) without damaging the radially compressed SMP foam.

[0073] While the example has dealt with the transition of an SMP foam to its primary state in response to thermal stimulation, an SMP foam can also be stimulated based on body temperature, warm saline solution, electromagnetic stimulation via a field supplied externally or internally, light from fiber optic cables, and interaction with electric current supplied via a wire adjacent to the foam.

[0074] In some embodiments, the SMP foam may be replaced with a hydrogel.

[0075] Example 2: In the compressed state, the first foam is compressed radially along a radius perpendicular to both the long axis and the short axis of the stent, as described in Example 1.

[0076] Example 3: The apparatus as described in Example 2, wherein the compressed length of the SMP foam is the length of the first foam, the length of the first foam is measured parallel to the long axis of the stent; and the expanded length of the SMP foam is the length of the second foam, the length of the first foam is substantially equal to the length of the second foam.

[0077] Example 4: The apparatus is as described in Example 2, wherein the first support column penetrates the SMP foam at at least one position so as to traverse from the first surface of the SMP foam to the second surface of the SMP foam, and the first and second surfaces face each other.

[0078] Example 5: The apparatus as described in Example 2, wherein the first support column is connected to the second support column at the first joint; the axis intersects the first joint but does not come into contact with the SMP foam; the axis is perpendicular to the long axis of the stent; and the axis is perpendicular to the short axis of the stent.

[0079] Example 6: The apparatus according to Example 2, further comprising an adhesive for connecting the SMP foam to the first and second support columns.

[0080] Example 7: The adhesive comprises an unfoamed polyurethane coating that is fixed and bonded in direct contact with the first support column; the SMP foam is fixed and bonded in direct contact with the polyurethane coating; and the polyurethane coating is the apparatus described in Example 6 for fixing and bonding the SMP foam to the first support column.

[0081] Example 8: The apparatus described in Example 7 is one in which the polyurethane coating is a curing thermosetting resin.

[0082] Example 9: The apparatus described in Example 7, wherein the polyurethane coating is thermoplastic.

[0083] Example 10: The apparatus is as described in Example 7, wherein the chemical composition of the polyurethane coating is equal to the chemical composition of the SMP foam.

[0084] Example 11: Polyurethane coating is SMP, the apparatus is as described in Example 10.

[0085] Example 12: The apparatus according to Example 6, further comprising an internal conduit between the valve and the SMP foam.

[0086] For example, the inner conduit may be a thermoplastic polyurethane membrane deposited on the stent support. Subsequently, the SMP foam may be bonded to the membrane with an adhesive. As described above, polyurethane may be used as the adhesive. That is, in one embodiment, a polyurethane adhesive may be used to bond the polyurethane SMP foam to the polyurethane membrane (when the membrane is bonded to the stent).

[0087] Example 13: The outer conduit can be made of polytetrafluoroethylene (PTFE), as described in Example 2.

[0088] Example 14: The apparatus described in Example 2, wherein the SMP foam is covalently bonded to iodine.

[0089] Example 15: The apparatus described in Example 14, wherein the SMP foam is poly(urethane-urea-amide).

[0090] Example 16: The apparatus described in Example 14, wherein the iodine is contained in the triiodobenzene monomer.

[0091] Example 17: The apparatus described in Example 2, wherein the SMP foam is obtained by the reaction of one or more polyols with one or more diisocyanates.

[0092] Example 18: The apparatus as in Example 2, wherein the SMP foam substantially covers most of the first surface of the third window but not most of any of the first, second, fourth, and fifth windows; the third window is directly adjacent to each of the first, second, fourth, and fifth windows; and there are no other stent windows between the third window and any of the first, second, fourth, and fifth windows.

[0093] Example 19: A further open-cell polyurethane thermosetting SMP foam is configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation; here the further SMP foam covers the first surface of the fourth window, which has the first and second surfaces substantially opposite to each other; the third support fixes and connects the further SMP foam; In the first direction, the further SMP foam is in the compressed secondary state; in the second direction, the further SMP foam is in the expanded primary state, as described in Example 2.

[0094] Example 20: The apparatus according to Example 19, wherein the SMP foam and the further SMP foam overlap each other such that their axes intersect together; the axes are perpendicular to the long axis of the stent; and the axes are perpendicular to the short axis of the stent.

[0095] The apparatus according to Example 2, wherein a further open-cell polyurethane thermosetting SMP foam is configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation; wherein the further SMP foam substantially covers the first surface of a sixth window, which is contained in the stent and has a first and second surface facing each other; the further SMP foam does not substantially cover the third window; the SMP foam substantially does not substantially cover the sixth window; further supports contained in the sixth window fixate and connect the further SMP foam; in the first direction, the further SMP foam is in the compressed secondary state; and in the second direction, the further SMP foam is in the expanded primary state.

[0096] Example 22: The apparatus according to Example 21, wherein the surface region of the SMP foam is the first surface region; the surface region of the further foam is the second surface region; and the first surface region is at least 20% larger than the second surface region.

[0097] Example 22 addresses an example where the scale or SMP foam segments differ in size, but other examples include SMP foam segments with different densities, compressibility, porosity, etc. For example, a higher-density foam may be directly adjacent to the valve annulus, while being axially sandwiched by a lower-density foam. This allows the higher-density foam to withstand uplift forces that are not present in the area removed from the valve annulus.

[0098] Example 23: The apparatus is as described in Example 2, wherein the SMP foam includes a monolithic SMP foam ring; the SMP foam ring is located outside the stent and surrounds the stent.

[0099] Example 24: The apparatus as described in Example 2, wherein a first plane parallel to the minor axis of the stent intersects the SMP foam, the first and second supports, and the first, second and third windows; a second plane parallel to the minor axis of the stent intersects the SMP foam, the third and fourth supports, and the third, fourth and fifth windows; the first plane does not intersect either the third or fourth supports; the first plane does not intersect either the fourth or fifth window; the second plane does not intersect either the first or second support; and the second plane does not intersect either the first or second window.

[0100] Example 25: The apparatus according to Example 2, wherein the first, second, third, and fourth supports each include at least one of nitinol, cobalt-chromium, and stainless steel.

[0101] Example 26: A device comprising a metal skeleton including first, second, third, and fourth pillars; a valve contained within the skeleton; and an open-cell polyurethane thermosetting shape memory polymer (SMP) foam configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation, wherein (a)(i) the first and second pillars fixate the SMP foam, and (a)(ii) the third and fourth pillars do not fixate the SMP foam; in the first direction, (b)(i) the stent has a first maximum stent outer diameter, (b)(ii) the stent has a first stent length measured parallel to the long axis of the stent, and (b)(iii) the SMP foam is in the compressed secondary state; in the second direction, (c)(i) the stent has a second maximum stent outer diameter longer than the first maximum stent outer diameter. (c)(ii) The stent has a second stent length shorter than the length of the first stent; (c)(iii) The SMP foam is in the expanded primary state; when the device moves from the first direction to the second direction, depending on the first and second supports that fix the SMP foam and the third and fourth supports that do not fix the SMP foam, the SMP foam is configured to move depending on the first and second supports but not on the third and fourth supports; a first plane perpendicular to the long axis of the stent intersects the SMP foam and the first and second supports; a second plane perpendicular to the long axis of the stent intersects the SMP foam and the third and fourth supports; the first plane does not intersect either the third or fourth support; the second plane does not intersect either the first or second support.

[0102] Example 1a: A device comprising a structural support skeleton including first, second, third, and fourth struts; a valve contained within the skeleton; and an open-cell polyurethane thermosetting shape memory polymer (SMP) foam configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation, wherein (a)(i) the first and second struts fixate the SMP foam, and (a)(ii) the third and fourth struts do not fixate the SMP foam; in the first direction, (b)(i) the stent has a first maximum stent outer diameter, (b)(ii) the stent has a first stent length measured parallel to the long axis of the stent, and (b)(iii) the SMP foam is in the compressed secondary state; in the second direction, (c)(i) the stent has a second maximum stent outer diameter longer than the first maximum stent outer diameter (c)(ii) The stent has a second stent length shorter than the length of the first stent; (c)(iii) The SMP foam is in the expanded primary state; when the device moves from the first direction to the second direction, depending on the first and second supports that fix the SMP foam and the third and fourth supports that do not fix the SMP foam, the SMP foam is configured to move depending on the first and second supports but not on the third and fourth supports; a first plane perpendicular to the long axis of the stent intersects the SMP foam and the first and second supports; a second plane perpendicular to the long axis of the stent intersects the SMP foam and the third and fourth supports; the first plane does not intersect either the third or fourth support; the second plane does not intersect either the first or second support.

[0103] Therefore, not all skeletons are made of metal. Some may be formed from polymers or other materials.

[0104] Example 2a: The apparatus as in Example 1a, wherein the adhesive is in direct contact with the first and second pillars and the SMP foam, and the SMP foam is directly bonded to each of the first and second pillars; however, neither the third nor the fourth pillar is in direct contact with the adhesive that is in direct contact with the SMP foam.

[0105] Example 3a: The apparatus according to Example 1a, comprising a membrane in contact with the first and second pillars, wherein the positions within the upper half of the SMP foam are directly bonded to the membrane via an adhesive in direct contact with the membrane and the SMP foam; and the lower half of the SMP foam is not directly bonded to the membrane via any adhesive, and is configured to slide on the membrane when the apparatus moves from the first direction to the second direction.

[0106] Example 4a: In the compressed state, the first foam is compressed radially along a radius perpendicular to both the long axis and the short axis of the stent, as described in any one of Examples 1a to 3a.

[0107] Example 5a: The SMP foam is the first foam in the compressed state, the length of the first foam is measured parallel to the long axis of the stent; the length of the SMP foam in the expanded state is the length of the second foam; the length of the first foam is substantially equal to the length of the second foam. This is the apparatus described in Example 4a.

[0108] Example 6a: The apparatus according to Example 4a, wherein the first support column penetrates the SMP foam at at least one position so as to traverse from the first surface of the SMP foam to the second surface of the SMP foam, and the first and second surfaces face each other.

[0109] Example 7a: The apparatus as described in Example 4a, wherein the first support column is connected to the second support column at the first joint; the axis intersects the first joint but does not come into contact with the SMP foam; the axis is perpendicular to the long axis of the stent; and the axis is perpendicular to the short axis of the stent.

[0110] Example 8a: The apparatus according to Example 1a, further comprising an adhesive for connecting the SMP foam to the first and second support columns.

[0111] Example 9a: The adhesive comprises an unfoamed polyurethane coating that is fixed and bonded in direct contact with the first support column; the SMP foam is fixed and bonded in direct contact with the polyurethane coating; and the polyurethane coating is the apparatus described in any of Examples 2a to 8a for fixing and bonding the SMP foam to the first support column.

[0112] Example 10a: The apparatus is the same as in Example 9a, but the polyurethane coating is a curing thermosetting resin.

[0113] Example 11a: The apparatus described in Example 9a, wherein the polyurethane coating is thermoplastic.

[0114] Example 12a: The apparatus described in Example 9a, wherein the chemical composition of the polyurethane coating is equal to the chemical composition of the SMP foam.

[0115] Example 13a: The apparatus described in Example 12a, wherein the polyurethane coating is SMP.

[0116] Example 14a: The apparatus according to Example 4a, wherein an internal conduit is included between the valve and the SMP foam.

[0117] For example, the inner conduit may be a thermoplastic polyurethane membrane deposited on the stent support. Subsequently, the SMP foam may be bonded to the membrane with an adhesive. As described above, polyurethane may be used as the adhesive. That is, in one embodiment, a polyurethane adhesive may be used to bond the polyurethane SMP foam to the polyurethane membrane (when the membrane is bonded to the stent).

[0118] Example 15a: The apparatus is as described in Example 4a, wherein the outer conduit contains polytetrafluoroethylene (PTFE).

[0119] Example 16a: The apparatus described in Example 4a, wherein the SMP foam is covalently bonded to iodine.

[0120] Example 17a: The apparatus described in Example 16a, wherein the SMP foam is poly(urethane-urea-amide).

[0121] Example 18a: The apparatus described in Example 16a, wherein the iodine is contained in the triiodobenzene monomer.

[0122] Example 19a: The apparatus described in Example 4a, wherein the SMP foam is obtained by the reaction of one or more polyols with one or more diisocyanates.

[0123] Example 20a: The apparatus as described in Example 4a, wherein the SMP foam substantially covers most of the first surface of the third window but not most of any of the first, second, fourth, and fifth windows; the third window is directly adjacent to each of the first, second, fourth, and fifth windows; and there are no other stent windows between the third window and any of the first, second, fourth, and fifth windows.

[0124] Example 21a: The apparatus according to Example 21a, wherein the further open-cell polyurethane thermosetting SMP foam is configured to expand from a compressed secondary state to an expanded primary state in response to a thermal stimulus; the further SMP foam covers the first surface of the fourth window having substantially opposing first and second surfaces; the third support fixes and connects the further SMP foam; in the first direction the further SMP foam is in the compressed secondary state; and in the second direction the further SMP foam is in the expanded primary state.

[0125] Example 22a: The apparatus according to Example 21a, wherein the SMP foam and the further SMP foam overlap each other such that their axes intersect together; the axes are perpendicular to the long axis of the stent; and the axes are perpendicular to the short axis of the stent.

[0126] Example 23a is the apparatus according to Example 4a, wherein a further open-cell polyurethane thermosetting SMP foam is configured to expand from a compressed secondary state to an expanded primary state in response to thermal stimulation; wherein the further SMP foam substantially covers the first face of a sixth window, which is contained in the stent and has a first and second face facing each other; the further SMP foam does not substantially cover the third window; the SMP foam substantially does not substantially cover the sixth window; further supports contained in the sixth window fixate and connect the further SMP foam; in the first direction, the further SMP foam is in the compressed secondary state; and in the second direction, the further SMP foam is in the expanded primary state.

[0127] Example 24a: The apparatus according to Example 23a, wherein the surface region of the SMP foam is the first surface region; the surface region of the further foam is the second surface region; and the first surface region is at least 20% larger than the second surface region.

[0128] Example 25a: The apparatus is as described in Example 4a, wherein the SMP foam includes a monolithic SMP foam ring; the SMP foam ring is located outside the stent and surrounds the stent.

[0129] Example 26a: The apparatus according to Example 4a, wherein the first, second, third, and fourth supports each include at least one of nitinol, cobalt-chromium, and stainless steel.

[0130] The above description of embodiments of the present invention has been presented for illustrative and explanatory purposes only. The detailed forms of the disclosure are not exclusive, and the present invention is not limited thereto. This specification and the claims include terms used solely for illustrative purposes, such as left, right, top, bottom, above, below, upper, bottom, first, second, etc., but these should not be interpreted restrictively. For example, the term indicating a relatively vertical position means a situation where the side of a substrate is the “top” surface of that substrate, and the substrate may actually be in any orientation, such that the “top” side of the substrate is lower than the “bottom” side of a standard reference frame, but still falls within the meaning of the term “top.” The term “above” in this specification (included in the claims) does not, unless otherwise specified, indicate that the first layer “above” the second layer is directly on or in direct contact with the second layer, and a third layer or other structure may exist between the first and second layers. Embodiments of the apparatus or product described herein can be manufactured, used or transported in numerous arrangements and orientations. Those skilled in the art will understand that many improvements and modifications are possible from the above teachings. Those skilled in the art will recognize various equivalent combinations and substitutions of the various components shown in the drawings. That is, the scope of the present invention is intended to be limited not by this detailed description, but by the claims appended herein.

Claims

1. Valve support structure comprising at least one of metal or polymer; The valve included within the valve support structure; Polyurethane shape memory polymer (SMP) foam; and A membrane including a skirt that folds onto the aforementioned SMP foam. An apparatus including, where, (a)(i) at least a portion of the first half of the SMP foam is fixedly bonded to the first portion of the valve support structure, and (a)(ii) no portion of the second half of the SMP foam is fixedly bonded to the second portion of the valve support structure. In the first direction, (b)(i) the valve support structure has a first maximum outer diameter, and (b)(ii) the valve support structure has a first length measured parallel to the long axis of the valve support structure; In the second direction, (c)(i) the valve support structure has a second maximum outer diameter that is longer than the first maximum outer diameter, and (c)(ii) the valve support structure has a second length that is shorter than the first length; Since at least a portion of the first half of the SMP foam is fixedly coupled to the first portion of the valve support structure, and no portion of the second half of the SMP foam is fixedly coupled to the second portion of the valve support structure, when the device moves from the first direction to the second direction, the SMP foam is configured to move depending on the first portion of the valve support structure, but independently of the second portion of the valve support structure; A first plane perpendicular to the long axis of the valve support structure intersects the SMP foam and the first portion of the valve support structure; A second plane perpendicular to the long axis of the valve support structure intersects the SMP foam and the second portion of the valve support structure; The first plane does not intersect with the second portion of the valve support structure, The second plane does not intersect the first portion of the valve support structure. Device.

2. The apparatus according to claim 1, wherein the membrane is located between the valve and the SMP foam.

3. The apparatus according to claim 1, wherein the membrane is located between the valve support structure and the SMP foam.

4. The apparatus according to any one of claims 1 to 3, wherein the film comprises a polymer.

5. The apparatus according to any one of claims 1 to 4, wherein the SMP foam is fixed and bonded to the film with an adhesive.

6. The apparatus according to any one of claims 1 to 5, wherein the membrane is fixedly bonded to at least the first half of the SMP foam to the first portion of the valve support structure.

7. The apparatus according to any one of claims 1 to 6, wherein the SMP foam includes a monolithic SMP foam ring.

8. The apparatus according to claim 7, wherein the monolithic SMP foam ring includes folds, pleats, or a combination thereof.

9. The apparatus according to claim 7 or 8, wherein a monolithic SMP foam ring surrounds the valve.

10. The apparatus according to any one of claims 1 to 9, further comprising a further polyurethane SMP foam overlapping the aforementioned SMP foam.

11. The apparatus according to any one of claims 1 to 6, comprising a plurality of the SMP foams, wherein the plurality of SMP foams contain the SMP foams, and the plurality of SMP foams surround a valve.

12. An apparatus according to any one of claims 1 to 11, comprising a conduit, wherein the conduit comprises the valve support structure, the valve, and the SMP foam.

13. The apparatus according to any one of claims 1 to 12, wherein the second half of the SMP foam is in contact with the second portion of the valve support structure.

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