Vascular flow management

Abstract

The implant device includes a frame having an axially expanding cylindrical form in an expanded configuration of the frame, and a radially expandable tube disposed within the frame.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 370,158, filed August 2, 2022, and entitled "VASCULAR FLOW MANAGEMENT," the complete disclosure of which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to the field of medical implantable devices. [Background technology]

[0003] Insufficient or low compliance of certain blood vessels, including arteries such as the aorta, can result in reduced perfusion, cardiac output, and other health complications. Restoring compliance and / or otherwise controlling flow in such vessels can improve patient outcomes. Summary of the Invention [Problem to be solved by the invention]

[0004] Described herein are devices, methods, and systems for facilitating the restoration of compliance properties in undesirably stiff blood vessels. Devices associated with various embodiments of the present disclosure may include a stent frame configured to dilate a native blood vessel and provide an interior space in which fluid channels / tubes may expand and retract / recoil, thereby providing changes in channel volume over the cardiac cycle. These volume changes may allow the vessel to mimic the compliance of a healthy blood vessel and / or otherwise facilitate blood flow, for example, during the diastolic phase of the cardiac cycle.

[0005] For purposes of summarizing the present disclosure, certain aspects, advantages, and novel features will be described. It will be understood that not all such advantages may necessarily be achieved in accordance with any particular example. Thus, the disclosed embodiments may be implemented in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages that may be taught or suggested herein. [Means for solving the problem]

[0006] The methods and structures disclosed herein for treating a patient also encompass similar methods and structures performed on or placed on a simulated patient, which are useful, for example, for training, demonstration, treatment and / or device development, and the like. The simulated patient can be physical, virtual, or a combination of physical and virtual. The simulation may include a simulation of all or part of a patient, such as, for example, the whole body, a body part (e.g., the chest), a system (e.g., the cardiovascular system), an organ (e.g., the heart), or any combination thereof. The physical elements may be natural, including human or animal cadavers or parts thereof, synthetic, or any combination of natural and synthetic. The virtual elements may be entirely in-computer or may be overlaid on one or more of the physical components. The virtual elements may be presented on any combination of screens, headsets, holographic, projections, loudspeakers, headphones, pressure transducers, temperature transducers, or presented using any combination of suitable technologies.

[0007] Various examples are shown in the accompanying drawings for illustrative purposes and should not be construed as limiting the scope of the present invention in any way. Additionally, various features of different disclosed embodiments may be combined to form additional embodiments that are part of the present disclosure. Throughout the drawings, reference numerals may be reused to indicate correspondence between referenced elements. [Brief explanation of the drawings]

[0008] [Figure 1] 1A and 1B show an exemplary representation of a patient's cardiac and vascular anatomy. [Figure 2] 2A and 2B provide cross-sectional and side views, respectively, of a blood vessel undergoing compliant contraction during the diastolic phase of the cardiac cycle. [Figure 3] 3A and 3B provide cross-sectional and side views, respectively, of the artery shown in FIGS. 2A and 2B during the systolic phase of the cardiac cycle, when the vessel undergoes compliant dilation. [Figure 4] FIG. 4 is a graph showing blood pressure over time in an example healthy patient. [Figure 5] FIG. 5 is a graph showing blood pressure over time in an exemplary patient with reduced aortic compliance. [Figure 6] 6A-6E provide illustrations of a compliance-enhancing implant device including one or more compressible fluid chambers according to one or more embodiments. [Figure 7] 7-1 and 7-2 show side cross-sectional views of the compliance-enhancing implant device of FIGS. 6A-6E in a compressed and relaxed configuration, respectively, according to one or more embodiments. [Figure 8] 8A-8E provide illustrations of a compliance-enhancing implant device including an inner elastic tube according to one or more embodiments. [Figure 9] 9-1 and 9-2 show side cross-sectional views of the compliance-enhancing implant device of FIGS. 8A-8E in inflated / expanded and relaxed configurations, respectively, according to one or more embodiments. [Figure 10] 10-1, 10-2 and 10-3 show cross-sectional side views of various example compliant implant devices with respective channel / tube shapes / configurations. [Figure 11] FIG. 11 illustrates a compliance-enhancing implant device including an inner elastic tube sutured at its proximal and / or distal ends to an outer frame, according to one or more embodiments. [Figure 12]FIG. 12 illustrates a compliance-enhancing implant device including an internal elastic tube with one or more circumferential inlets / outlets and / or fluid channels / pleats according to one or more embodiments. [Figure 13] 13-1 and 13-2 illustrate side views of a compliance-enhancing implant device in a relaxed and expanded configuration, respectively, according to one or more embodiments. [Figure 14] 14-1, 14-2, and 14-3 show a flow diagram of a process for implanting a compliance-enhancing implant device according to one or more embodiments. [Figure 15] 15-1, 15-2, and 15-3 provide images of compliance-enhancing implant devices and specific anatomical structures corresponding to the operation of the processes of FIGS. 14-1, 14-2, and 14-3, according to one or more embodiments. [Figure 16] Figures 16-1 and 16-2 show the compliance enhancing effect of the implant device in high and low pressure stages / conditions, respectively. [Figure 17] 17A, 17B, and 17C provide a side view, a side cross-sectional view, and an axial view, respectively, of a valved, compliant-enhancing implant device according to one or more embodiments. [Figure 18]

[0013] Figure 18 illustrates a compliance-enhanced implant device including a valve portion according to one or more embodiments. Figures 18-1, 18-2, and 18-3 illustrate respective designs of the valve portion of a compliance-enhanced implant device according to one or more embodiments. [Figure 19] FIG. 19 illustrates an aortic anatomy with a valved compliance-enhancing implant device deployed in an exemplary location in the anatomy, according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0009] The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

[0010] Although certain preferred examples are disclosed below, it should be understood that the inventive subject matter extends beyond the specifically disclosed examples to other alternative examples and / or applications, as well as modifications and equivalents thereof. Accordingly, the scope of claims that may arise from this specification is not limited by any of the specific examples described below. For example, in any method or process disclosed herein, the acts or operations of the method or process may be performed in any suitable order and are not necessarily limited to any particular disclosed order. Various operations may be described sequentially as multiple separate operations, in a manner that may be useful for understanding a particular example, but the order of description should not be construed as implying that these operations are order-dependent. Additionally, structures, systems, and / or devices described herein may be embodied as integrated components or as separate components. For purposes of comparing various examples, certain aspects and advantages of these examples are described. Not all such aspects or advantages are necessarily achieved by any particular example. Thus, for example, the various examples may be implemented in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other aspects or advantages that may also be taught or suggested herein.

[0011] Certain reference numbers are reused throughout the figures of this disclosure for convenience in reference to devices, components, systems, functions, and / or modules whose functions may be similar in one or more respects. However, with respect to any examples disclosed herein, the reuse of common reference numbers in figures does not necessarily indicate that such functions, devices, components, or modules are identical or similar. Rather, one skilled in the art can learn from the context as to the degree to which the use of common reference numbers may suggest similarity between the referenced subject matter. The use of a particular reference number in the context of a description of a particular figure can be understood as relating to the device, component, aspect, function, module, or system identified in that particular figure, and not necessarily as relating to any device, component, aspect, function, module, or system identified with the same reference number in another figure. Furthermore, aspects in separate figures identified with a common reference number can be construed as sharing functionality or as being entirely independent of one another.

[0012] Where an alphanumeric reference identifier is used that includes a numeric portion and an alphabetic portion (e.g., "10a," where "10" is the numeric portion and "a" is the alphabetic portion), a reference in the written description to only the numeric portion (e.g., "10") may refer to any feature identified in a figure using such a numeric portion (e.g., "10a," "10b," "10c," etc.), even if such feature is identified using a reference identifier that connects its numeric portion with one or more alphabetic characters (e.g., "a," "b," "c," etc.). That is, a reference in the written description herein to feature "10" may be understood to refer, by way of example, to the identified feature "10a" in a particular figure of the present disclosure, or to either the identifier "10" or "10b" in the same or another figure.

[0013] Certain standard anatomical terms of location are used herein to refer to animal, i.e., human, anatomical structures with respect to various embodiments. While certain spatially relative terms such as "outer," "inner," "superior," "lower," "upper," "vertical," "horizontal," "top," "bottom," and similar terms are used herein to describe the spatial relationship of one device / element or anatomical structure to another device / element or anatomical structure, it is understood that these terms are used herein for ease of description to describe the positional relationships between the elements / structures illustrated in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of elements / structures in use or operation in addition to the orientation depicted in the figures. For example, an element / structure described as "above" another element / structure may represent a position that is below or to the side of such other element / structure with respect to the intended patient or alternative orientations of the element / structure, and vice versa. It should be understood that spatially relative terms, including those listed above, can be understood relative to the respective illustrated orientations of the referenced figures.

[0014] Vascular Anatomy and Compliance Specific examples are disclosed herein with respect to vascular implant devices, particularly compliance-enhanced implant devices implanted in the aorta. However, while certain principles disclosed herein may be particularly applicable to the aortic anatomy, it should be understood that compliance-enhanced implant devices according to the present disclosure may be implanted or configured for implantation in any suitable or desirable blood vessel or other anatomical structure, such as the inferior vena cava.

[0015] The anatomy and vasculature of the heart are described below to aid in understanding certain inventive concepts disclosed herein. In humans and other vertebrates, the heart generally comprises a muscular organ having four pumping chambers, the flow of which is controlled at least in part by various cardiac valves, namely, the aortic valve, the mitral valve (or bicuspid valve), the tricuspid valve, and the pulmonary valve. The valves may be configured to at least in part control the flow of blood to respective regions and / or vessels of the heart (e.g., the ventricles, the pulmonary artery, the aorta, etc.) in response to pressure gradients that exist during various phases of the cardiac cycle (e.g., relaxation and systole). Contraction of the various cardiac muscles may be facilitated by signals generated by the heart's electrical system.

[0016] FIG. 1 illustrates an exemplary representation of a heart 1 and associated vascular system with various functions relevant to one or more embodiments of the present disclosure. Heart 1 includes four chambers: left atrium 2, left ventricle 3, right ventricle 4, and right atrium 5. In terms of blood flow, generally, blood flows from the right ventricle 4 through pulmonary valve 9 into the pulmonary artery, which separates the right ventricle 4 from the pulmonary artery 11 and is configured to open during systole to allow blood to be pumped toward the lungs and close during diastole to prevent blood from flowing back into the heart from the pulmonary artery 11. The pulmonary artery 11 carries deoxygenated blood from the right side of the heart to the lungs. As shown, the pulmonary artery 11 includes the pulmonary trunk and left and right pulmonary arteries that branch off from the pulmonary trunk.

[0017] The tricuspid valve 8 separates the right atrium 5 from the right ventricle 4. The tricuspid valve 8 generally has three cusps / leaflets and may generally close during ventricular contraction (i.e., systole) and open during ventricular expansion (i.e., diastole). The mitral valve 6 generally has two cusps / leaflets and separates the left atrium 2 from the left ventricle 3. The mitral valve 6 is configured to open during diastole to allow blood from the left atrium 2 to flow into the left ventricle 3 and, when functioning properly, to close during systole to prevent blood from flowing back into the left atrium 2. The aortic valve 7 separates the left ventricle 3 from the aorta 12. The aortic valve 7 is configured to open during systole to allow blood from the left ventricle 3 to enter the aorta 12 and to close during diastole to prevent blood from flowing back into the left ventricle 3.

[0018] A heart valve may generally include a relatively dense fibrous ring, referred to herein as the annulus, and multiple leaflets, or cusps, attached to the annulus. Generally, the size of the leaflets or cusps may be such that, when the heart contracts, increased blood pressure within the corresponding heart chamber causes the leaflets to at least partially open, allowing flow from the heart chamber. When pressure within a heart chamber decreases, pressure within the subsequent heart chamber or blood vessel may prevail and push the leaflets back. As a result, the leaflets / cusps appose each other, thereby closing the flow path. Dysfunction of a heart valve and / or associated leaflets (e.g., pulmonary valve dysfunction) can lead to valve leakage and / or other health complications.

[0019] The atrioventricular (mitral and tricuspid) heart valves are generally associated with a collection of chordae tendineae and papillary muscles (not shown for visual clarity) that anchor the leaflets of each valve to promote and / or facilitate proper closure of the leaflets and prevent their prolapse. The papillary muscles may generally include, for example, finger-like projections from the ventricular wall. The valve leaflets are connected to the papillary muscles by the chordae tendineae. A muscular wall 17, called the septum, separates the left 2 and right 5 atria and the left 3 and right 4 ventricles.

[0020] The vascular system in the human body, which may also be referred to as the circulatory system, cardiovascular system, or vascular system, comprises a complex network of blood vessels with different structures and functions, including various veins (venous system) and arteries (arterial system). Generally, arteries, such as the aorta 16, carry blood away from the heart, while veins, such as the inferior vena cava and superior vena cava, return blood to the heart.

[0021] The aorta 16 is a compliant arterial vessel that buffers and conducts pulsatile left ventricular output and contributes the largest component of total compliance to the arterial tree. The aorta 16 includes the ascending aorta 12, which originates at the opening of the aortic valve 7 in the left ventricle of the heart. The ascending aorta 12 and the pulmonary trunk 11 twist around each other, causing the aorta 12 to begin posterior to the pulmonary trunk 11 but terminate twisted to the right and anterior of it. Of the various segments of the aorta 16, the ascending aorta 12 is relatively more frequently affected by aneurysms and dissections, often requiring open-heart surgery for repair. The transition from the ascending aorta 12 to the aortic arch 13 is at the pericardial reflection on the aorta. At the root of the ascending aorta 12, the lumen contains three small pockets between the cusps of the aortic valve and the aortic wall, called the aortic sinuses or sinuses of Valsalva. The left aortic sinus contains the origin of the left coronary artery, and the right aortic sinus similarly gives rise to the right coronary artery. These two arteries together supply the heart.

[0022] As mentioned above, the aorta is connected to the heart 1 via the aortic valve 7, which leads to the ascending aorta 12, which gives rise to the brachiocephalic artery 27, the left common carotid artery 28, and the left subclavian artery 26 along the aortic arch 13, and then continues as the descending thoracic aorta 14 and the abdominal aorta 15. References herein to the aorta will be understood to refer to the ascending aorta 12 (also referred to as the "ascending thoracic aorta"), the aortic arch 13, the descending aorta or thoracic aorta 14 (also referred to as the "descending thoracic aorta"), the abdominal aorta 15, or other arterial vessels or portions thereof.

[0023] Arteries, such as the aorta 16, may utilize vascular compliance (e.g., arterial compliance) to store and release energy through stretching of the vessel wall. The term "compliance" is used herein according to its broad and ordinary meaning to refer to the ability of an arterial blood vessel or prosthetic implant device to expand, dilate, stretch, or otherwise deform in response to an increase in transmural pressure or the tendency of a blood vessel (e.g., an artery) or prosthetic implant device, or portion thereof, to resist recoil toward its original dimensions upon the application of an expansive or compressive force.

[0024] Arterial compliance facilitates perfusion of organs in the body with oxygenated blood from the heart. Generally, healthy aortas and other major arteries in the body are at least partially elastic and compliant, allowing them to act as blood reservoirs and fill with blood as the heart continues to contract and generate pressure during systole and pump blood to the body's organs during diastole. In elderly individuals and patients with heart failure and / or atherosclerosis, aortic and other arterial compliance may be reduced or lost to some extent. This reduced compliance can reduce blood supply to the body's organs due to reduced diastolic blood flow. Among the risks associated with insufficient arterial compliance, a significant risk posed to such patients is reduced blood supply to the myocardium itself. For example, during systole, cardiac contractions that hold the heart at relatively high pressures generally result in little or no blood flowing into the coronary arteries and myocardium. During diastole, the myocardium generally relaxes, allowing blood to flow into the coronary arteries. Therefore, myocardial perfusion depends on diastolic blood flow and, therefore, aortic / arterial compliance.

[0025] Inadequate perfusion of the myocardium can lead to and / or be associated with heart failure. Heart failure is a clinical syndrome characterized by specific symptoms, including shortness of breath, ankle swelling, fatigue, and others. Heart failure may be accompanied by specific signs, including, for example, elevated jugular venous pressure, pulmonary crackles, and peripheral edema, which may be caused by structural and / or functional cardiac abnormalities. These conditions can result in reduced cardiac output and / or elevated intracardiac pressure at rest or during stress.

[0026] While FIGS. 2A and 2B provide cross-sectional and side views, respectively, of a compliant blood vessel 215, such as an artery (e.g., the aorta), that experiences a compliant radial contraction during the diastole phase of the cardiac cycle, FIGS. 3A and 3B illustrate a blood vessel 215 that experiences a compliant expansion during the systole phase of the cardiac cycle. As will be appreciated by those skilled in the art, the systole phase of the cardiac cycle is associated with the pumping phase of the left ventricle, while the diastole phase of the cardiac cycle is associated with the resting or filling phase of the left ventricle. As shown in FIGS. 3A and 3B, with adequate arterial compliance, an increase in pressure within an artery generally results in an increase in volume within the artery. With respect to the aorta, as shown in FIGS. 3A and 3B, as blood is pumped through the aortic valve 207 and into the aorta 215, the pressure in the aorta increases, causing the diameter of at least a portion of the aorta to expand. A first portion of the blood entering the aorta 215 during systole may pass through the aorta during systole, while a second portion (e.g., approximately half of the total blood volume) may be stored in the expanded volume caused by compliant dilation of the blood vessel, thereby storing energy to contribute to perfusion during diastole. A compliant aorta may generally stretch with each heartbeat such that the diameter of at least a portion of the aorta expands.

[0027] The tendency of arteries to stretch in response to pressure as a result of arterial compliance can have a significant effect on perfusion and / or blood pressure in some patients. For example, a relatively compliant artery may be adjusted to deform more easily than a less compliant artery under the same pressure and / or volume conditions. Compliance (C) may be calculated using the following equation, where ΔV is the change in volume (e.g., mL) and ΔP is the systolic to diastolic pulse pressure (e.g., mmHg):

number

[0028] Aortic stiffness and decreased compliance can result in increased systolic blood pressure, which in turn can lead to increased intracardiac pressure, increased afterload, and / or other complications that can worsen heart failure. Aortic stiffness can further result in decreased diastolic blood flow, which can lead to decreased coronary perfusion, decreased cardiac supply, and / or other complications that can also worsen heart failure.

[0029] As shown in Figures 2A and 2B, arterial compliance causes the vessel walls to recoil inward during diastole, creating pressure within the vessel that can continue to push blood through artery 215 even when valve 207 is closed. For example, during systole, approximately 50% of the blood entering artery 215 through valve 207 may pass through the artery, while the remaining 50% may be stored in the artery, enabled by the dilation of the vessel walls. Some or all of the blood stored in artery 215 may be pushed through the artery by the contracting vessel walls during diastole. For patients experiencing arteriosclerosis that causes a lack of compliance, their arteries may not operate effectively according to the dilation / constriction function shown in Figures 2A and 2B and 3A and 3B.

[0030] The arterial compliance restoration devices, methods, and concepts disclosed herein are generally described in the context of the ascending aorta, however, it should be understood that such devices, methods, and / or concepts may be applied in connection with any other artery or blood vessel.

[0031] 4 is a graph showing blood pressure over time in an example patient with a healthy, compliant aorta, where the arterial pressure is represented as a combination of an anterior systolic pressure wave 701 and a posterior diastolic pressure wave 702. The combination of the systolic wave 702 and the diastolic wave 701 is represented by waveform 703.

[0032] FIG. 5 is a graph showing blood pressure over time in an exemplary patient with reduced aortic compliance. For reference purposes, the graph in FIG. 5 illustrates the example combined waveform 703 shown in FIG. 4. When low compliance is present, less energy may be stored in the aorta compared to a healthy patient. Thus, the systolic waveform 802 may indicate increased pressure during systole compared to a patient with normal compliance, while the diastolic waveform 801 may indicate decreased pressure during diastole compared to a patient with normal compliance. The resulting combined waveform 803 may therefore represent an increased systolic peak and decreased diastolic pressure, which may lead to various health complications. For example, changes in the waveform may affect left ventricular loading and adversely affect coronary perfusion.

[0033] Given the health complications that may be associated with reduced arterial compliance, as discussed above, it may be desirable to at least partially alter the compliance characteristics of the aorta or other arteries or blood vessels in certain patients and / or under certain conditions to improve the health of the heart and / or other organs. Disclosed herein are various devices and methods for at least partially restoring compliance to blood vessels, such as the aorta. Certain embodiments disclosed herein achieve arterial compliance restoration through the use of implantable, compliant fluid channels / tubes through which blood circulation may flow. For example, a compliance restoration device according to the present disclosure may comprise an expandable fluid channel that expands and stores energy during periods of higher pressure (e.g., during systole) of the cardiac cycle and contracts / compresses during periods of lower pressure (e.g., during diastole) to return the stored energy to the circulation and increase flow through the channel.

[0034] In some embodiments, the disclosed devices include compressible fluid (e.g., gas) chambers surrounding the compliant fluid channels of the device, which may be disposed within a vasodilator outer frame. In some embodiments, the disclosed devices include elastic / compliant tubes / channels disposed within the vasodilator frame, which provide a space outside the compliant tubes / channels that may contain circulating blood, which may periodically fill and empty from the space in a manner that increases compliance and / or diastolic flow within the vessel. The compliant channels / tubes may be fixed in place in a frame (e.g., a stent frame), which may comprise metal or other at least partially rigid material. Such a frame may be configured to expand within a target vessel, causing its expansion, which may serve both to secure the frame in a desired position within the target vessel and to create a space within the vessel in which the compliant channels / tubes can radially expand.

[0035] The devices of the present disclosure may include additional fixation mechanisms to provide secure retention within the target vessel. For example, barb-type anchors may be integrated into the outer frame. Certain covers and / or linings (e.g., fabrics, polymers) may be implemented on the outer frame to improve the fluid-tight properties of the implant device and / or promote ingrowth with native vascular tissue. The compliance restoration devices disclosed herein may serve, at least in part, to increase coronary perfusion.

[0036] Compliance-enhancing implant devices The present disclosure relates to systems, devices, and methods for restoring and / or increasing compliance to the aorta or other arterial (or venous) vessel, providing improved perfusion of the myocardium and / or other body organs. Examples of the present disclosure may include a compliant tubular device configured to direct blood circulation therethrough such that the compliant / elastic expansion of the tube during systole can be returned to the circulation during diastole, thereby decreasing systolic pressure and increasing diastolic pressure. In contrast to solutions involving vascular grafts and / or resections, by placing a compliant tubular implant within an at least partially rigid outer frame that expands and remains within the native vessel, occurrences of blood leaks and / or ruptures of the expandable inner tube can be contained within the target vessel, thereby reducing the risks associated with extravascular arterial blood leaks, such as within the abdominal and / or thoracic cavities.

[0037] 6A-6E provide illustrations of a compliant implant device 30 including a tubular structure 40 having an axial interior / central fluid channel 49 formed by an inner tube / layer 41 configured to radially expand and recoil / compress based on changing pressure conditions within the channel 49. The radially expandable tube 41 may be disposed around one or more sealed compressible fluid chambers 42, such that radial expansion causing an increase in the volume of the channel 49 causes compression of the chambers 42 and / or fluid / medium (e.g., gas and / or foam) 45 therein. As the inner tube 41 radially expands and contracts, the volume of the channel 49 increases and decreases in a manner that provides compliance characteristics to the vessel in which it is implanted. The compliant channel 49 is defined / formed by the expandable inner tube 41. The inner tube 41 may further function as the radial inner diameter / boundary of the compressible fluid chambers 42.

[0038] The frame 31 is tubular in form with an axial channel therethrough and has an expanded inner diameter D m (e.g., its inner region 301), and such expansion of the frame 31 within the native vessel (e.g., the aorta) may serve to expand the native vessel to some extent. For example, the inner diameter D m may advantageously be at least 20% larger than the diameter of the native blood vessel in the region where the frame is deployed. In some implementations, the diameter D m is at least 30%, 35%, 40%, 45%, or 50% greater than the diameter of the native blood vessel. Thus, it should be understood that examples of the present disclosure relate to compliant implant devices that, when implanted / deployed, perform a vasodilator function, thereby substantially increasing the diameter of the native blood vessel, and maintain such expansion when the implant is positioned / implanted at a target anatomical site, such expansion functioning to provide space for radial expansion of inner tube / layer 41. For example, compressible gas 45 within chamber 42 may be compressed within the space provided between inner tube 41 and the expanded / expanded blood vessel and frame 31.

[0039] Dilation of native blood vessels in connection with embodiments of the present disclosure may present certain risks to patients. For example, particularly with respect to relatively stiff and / or thin vessel segments, vessel dilation can result in rupture or other tissue damage. If such rupture causes bleeding, such an event can have serious impacts on the patient's health, potentially leading to severe injury or death. The concepts of the present disclosure can be implemented in a manner that reduces these risks. For example, some implementations, such as the embodiment shown in FIGS. 6A-6E, can include an outer frame 31 having a gradually increasing diameter moving from the axial end 33 of the frame 31 toward the axial center 302, as shown, which can provide reduced strain on the native vascular tissue compared to embodiments in which the frame diameter is larger than the native vessel and constant along its entire length. Furthermore, it may be desirable for the expansion / deployment of the frame 31 to be performed in a gradual and atraumatic manner. For example, self-expansion or balloon expansion of the frame can be performed while the native tissue is expanding from its native diameter to an expanded diameter D. m The implementation may be relatively slow to allow the system to adapt and respond gradually to expansion to the new system.

[0040] The implant device 30 is configured to restore compliance to an implanted target vessel, such as the aorta, to improve myocardial perfusion. The device 30 may be a percutaneously positionable implant configured to be compressed (e.g., radially compressed) and transported within a delivery catheter or other tubular delivery system. The radially expandable inner tube 41 may have a straight cylindrical shape in a native, relaxed, and / or decompressed configuration / state, while in a radially expanded, pressurized configuration / state, the tube 41 may have an outwardly convex (e.g., inwardly concave) cylindrical shape that may resemble the shape of the expanded frame 31 (described in detail below) of the device 30. The device 30 may advantageously function as an arterial flow optimizer to generate vascular compliance.

[0041] Device 30 includes an outer frame 31, which may be an expandable stent-type frame configured to radially expand from a compressed delivery configuration to an expanded state shown in FIG. 6A . To achieve this change in shape and size of frame / abutment 31, frame 31 may have a structure including a plurality of struts forming an array of cells 35, which may have any suitable or desired shape (e.g., oval / elliptical, diamond / rhombic, hexagonal diamond / polygonal, etc.). Cells 35 may be arranged in any number of circumferential rows and axial or longitudinal rows in direction A. In some embodiments, the minor axes of cells 35 extend in the circumferential direction and the major axes of cells 35 extend in the axial direction A, or vice versa. In some embodiments, adjacent cells 35 are connected to each other circumferentially and / or axially by connecting struts 36.

[0042] The cells 35 of the frame 31 may be formed using any suitable process, such as by stamping or machining the frame structure from a metal sheet or tube. The frame 31 may be made of any at least partially rigid material, such as metal or plastic. For example, the frame may include stainless steel or nitinol. If nitinol or other shape-memory metals or materials are implemented on the frame 31, the frame may be self-expanding. In some implementations, the array of struts 36 is formed from a sheet of metal, which is rolled into a cylinder to form the tubular / cylindrical form of the frame configured for placement within a blood vessel. In some implementations, a balloon catheter can be used to expand the frame 31 for fixation to the wall of an artery or other blood vessel or body cavity.

[0043] As described above, in addition to the frame 31, the device 31 includes an expandable (e.g., elastic) tube / channel 41 disposed within the frame 31. In some implementations, as shown in FIGS. 6A-6E, the tube 41 is part of an elastic, multi-layered, cylindrically toroidal (e.g., axially stretched, donut-shaped) balloon inner member 40 configured such that the outer 44 and inner 41 layers / walls of the inner member / tube 40 compress / combine in response to a pressure gradient between blood flowing through the axial channel 49 of the inner member / tube 40 and a gas or other fluid / medium 45 disposed within a compartment / chamber 42 of the inner cylindrical balloon 40. The device 30 may be implanted, for example, in the ascending aorta, e.g., in the region immediately above the aortic valve.

[0044] The radially expandable inner tube / layer 41 of the compliance tube / member 40 disposed within the cylindrical outer stent frame 31 defines an axial blood flow path / conduit 49 therethrough. In some embodiments, the outside of the frame 31 is covered with a fabric or polymer cover 32. The stent frame 31 may be a self-expanding and / or balloon-expandable stent. The frame 31 and / or balloon tube 40 may have a diameter of 0.2 mm at the axial end D as shown. e than the axial center D m The device may have an axially bulbous / bulged outer diameter such that it is larger at axial extension. Such a bulbous / bulged shape may facilitate a tighter fit of the device within the target vessel into which it is implanted.

[0045] The frame 31 and / or outer layer 44 of the inner balloon / tube 40 may advantageously have a shape that accommodates and facilitates compliant expansion of the inner tubular layer 41. For example, the inner tube 41 may have a diameter D in its relaxed / uncompressed (e.g., diastolic) configuration / state. t For example, the flow path 49 may be defined as having a diameter D t is the diameter D e The diameter D of the end of the frame 31, for example, within 10% of the dimension / distance of ePossible exemplary values that can be deviated from while still remaining within the context of this disclosure include D t may be a value / dimension of approximately 1-2 cm, and D M may be a value / dimension between 3 and 6 cm, D e may be a value / dimension of 1.5-3 cm in some implementations.

[0046] As shown, the frame 31 may have the shape of a convex cylinder, and the diameter of the frame 31 is the axis / length L of the frame 31. f For example, as shown, the frame diameter D e may be relatively small / narrow at one or both ends 33i, 33o of the frame, with the diameter of the frame expanding from the end 33 towards the axial / longitudinal center 302 of the frame 31 to a diameter D m In some embodiments, the increase in diameter moving toward axial center 302 may be gradual and / or continuous, as in the illustrated embodiment. However, in some embodiments, the diameter of the frame may increase beyond a maximum diameter D m The frame 31 may expand in a stepwise fashion so that the expanded diameter covers a substantial portion of the length of the frame (e.g., more than half the length of the frame). For example, the frame 31 may be configured such that the expanded diameter is greater than the overall length L of the frame 31. f The length L of the frame 31 is set so as to extend over the inner section 301 of the frame representing at least half of the f Narrower frame diameter D at the ends / outer parts / quarters of e to the expanded frame diameter Dm.

[0047] In some applications, the diameter D of the end portion 33 of the frame 31 e may be sized to match the diameter of the native vessel in which the frame 31 is to be deployed. For example, the diameter D of the end portion 33 of the frame 31 eIt may be desirable for the diameter of the aorta to be within 20% of the diameter of the native aorta in that particular target segment. Generally, the diameter of the ascending aorta may be less than about 2.1 cm. For the abdominal aorta, the diameter may be less than about 3.0 cm. The wall of the aorta may be composed of three layers, including the intima, media, and adventitia layers. While the intima is relatively thin, the media contains elastic fibers and smooth muscle cells that form a spiral layer of tissue, providing strength to the aortic wall, and the adventitia provides nourishment for the arterial and venous vessels. The total wall thickness of the aorta in the region where an implant according to the present disclosure may be implanted may generally be less than about 4 mm. The frame 31 is advantageously configured to expand the target aortic vessel to a diameter at the axial center of the frame that is 20% larger than the respective aortic diameters listed above, depending on the particular target vessel segment in which the implant is to be implanted, while not causing rupture or excessive trauma to the native vessel wall.

[0048] The convex cylindrical shape of the frame 31, when combined with the generally straight cylindrical shape / configuration of the inner tube / layer / channel 41, may advantageously provide a space 303 between the frame 31 and the tubular channel 49 defined by the inner tube / layer 41 when the tube / layer 41 is in a relaxed configuration, wherein the tube / layer 41 can expand within the space 303 to provide compliance. The inner tube / layer 41 can be configured to cycle between a relaxed state (where the tube 41 is generally cylindrical or slightly concave or convex in the relaxed state) during periods of low pressure (e.g., diastole of the cardiac cycle) and a radially expanded state (where the tube 41 expands / curves outward radially toward the frame 31 within the space 303 provided by the expansion of the blood vessel by the frame 31) during periods of high pressure (e.g., systole of the cardiac cycle). That is, the shape and dimensions of the frame 31 advantageously provide the space 303 in which the tube / layer 41 is permitted to radially expand, which can occur within the expanded target blood vessel. By allowing compliant expansion to a diameter larger than the native pre-implantation diameter of the native vessel (e.g., the aorta) (e.g., at least 20% larger than the diameter of the native vessel prior to its expansion by the frame 31) without requiring grafting, cutting, and / or resection of the native vessel, the risk associated with vessel rupture can be reduced or eliminated. In some embodiments, the space 303 is primarily occupied by a fluid chamber 42 between the inner tube 41 and the outer layer 44 of the compressible balloon 40, and radial expansion of the inner tube layer 41 causes compression of the fluid (e.g., gas) 45 disposed within the chamber 42 of the balloon 40, such that the space 303 between the inner tube layer 41 and the frame 31 and outer layer 44 decreases as pressure in the channel 49 increases and the tube 41 expands.

[0049] Without the expansion of the natural blood vessels, as achieved by the frame 31, the space available within the frame for blood flow and expansion of the inner tube / layer 41 would be limited. For example, if the frame 31 were to extend beyond the diameter D of the tubular channel 49, tIf the frame 31 has a constant diameter slightly larger than the diameter of the native blood vessel, the inner tube / layer 41 cannot radially expand by a significant amount due to interference from the frame. Thus, the ability of the tube 41 to cyclically change volume in a manner that adds compliance to the blood circulation is limited. That is, a convex cylindrical shape of the frame 31, where the frame has a diameter at its largest diameter that is at least 20%, 30%, 40%, and / or 50% larger than the diameter of the native blood vessel, increases the ability of the inner tube 41 to add compliance to the blood circulation.

[0050] The outer frame 31 may be at least partially covered with a fabric or polymer coating or covering 32 that may promote tissue ingrowth at the inner diameter of a native blood vessel. The covering 32 may be disposed on an outer surface or region of the frame 31 and / or may be disposed / applied to the inner diameter of the frame 31 on its interior side. For example, a layer of covering 32 may, in some implementations, be disposed between the outer frame 31 and the tube 40. In some implementations, the covering 32 comprises a fabric or polymer sleeve that may be at least partially elastic or alternatively inelastic. The covering 32 may be applied onto or within the frame 31 in any suitable or desirable manner. For example, in some implementations, the covering 31 may be applied using an electro- or mechanical spinning (e.g., rotary jet spinning, electrospinning, or the like) application process, or other deposition process known to those skilled in the art.

[0051] The frame 31 may be a self-expanding and / or balloon-expandable stent frame. As described above, the frame 31 and / or the tubular member 40 may have an axially bulbous / bulged outer diameter such that its diameter is substantially larger at its axial center than at one or more of its axial ends 33, as shown. Such a bulbous / bulged shape may facilitate a tighter fit of the device 30 within the vessel into which it is implanted. The frame 31 may include barbs or other anchors 51 associated with its outer diameter to engage / embed with the target native vessel wall and secure the device in place. In some implementations, the barbs / anchors 51 penetrate through the outer covering / coating 32 and into the native tissue to secure the frame 31 in place.

[0052] As shown, a compliance-enhancing tube 40, which may contain one or more compressible fluid / gas chambers 42, may be coupled to the frame 31 at one or both axial ends 33 of the frame 31. For example, a tubular balloon 40 may be sutured to a respective ring structure 37 at either or both axial ends 33 of the stent frame 31. For example, such ring structures 37 may be integral with the frame 31 or may be attached in some manner to one or both axial ends 33 thereof. For example, the rings 37 may be attached to the frame 31 using sutures, wires, or other attachment means 137.

[0053] The compressible tube 40 may further be sewn or otherwise secured / attached to the axial end 33 of the frame 31. For example, the tube 40 may be sewn to the suture ring 37 or other structure of the frame 31, or may be attached using adhesive or other attachment means. In some implementations, the distal end portion 43 of the tube 40 may be heat sealed, mechanically crimped, or otherwise sealed in such a manner that suturing through such portion and / or openings formed in such portion do not provide fluid access to the internal chamber 42 or otherwise disrupt its seal. That is, the distal end portions 43i, 43o of the tube 40 may comprise one or more layers of material without a fluid-filled chamber disposed therein, formed therein, or exposed therein, to allow suturing or other attachment without risk of puncturing the chamber 42. In some implementations, the axial end portion 433 of the tube 40 may be folded / wrapped around the end portion 33 of the frame 31 and secured to the frame on its outer diameter. For example, an O-ring or other tool may be used around the folded portion of the tube 40 to hold / seal the tube portion to the frame 31. For example, the O-ring may be crushed against the frame 31, thereby pinching the tube portion against the frame 31.

[0054] The tubular balloon 40 may have a cylindrical toroidal shape, with the flow channel 49 running down the axis of the tube 40. While shown as a cylindrical / elliptical tube / toroid, in some embodiments, the elastic member / balloon 40 has the shape of a circular torus. The elastic tube 40 may function as an arterial flow optimizer, generating vascular compliance, as described in detail herein. While described as elastic in some contexts, it should be understood that the tube 40 may be at least partially inelastic. For example, either or both of the inner layer 41 and outer layer 44 of the tube 40 may be inelastic. In some implementations, the inner layer / tube 41 is elastic to allow its radial expansion / distention, while the outer layer 44 is at least partially inelastic.

[0055] The chamber 42 of the tubular balloon 40 can compress in the presence of high pressure levels (e.g., systolic aortic pressure) and tend to expand to a larger volume as pressure decreases (e.g., diastolic aortic pressure). This expansion induces blood flow within the channel 49 of the tube 40, thereby inducing blood flow within the target vessel (e.g., the aorta). The fluid 45 can be any suitable or desirable compressible fluid, such as a compressible gas. In some embodiments, the tubular balloon 40 comprises a compressible foam disposed between the inner and outer layers 41 and 44 of the balloon 40 and / or between the inner tubular layer 41 and the frame 31. That is, the illustrated medium 45 between the inner and outer layers 41 and 44 can include a foam having a compressible gas occupying its interior space / pockets. The foam can be configured to provide structure for the balloon 40 within the chamber 42. A compressible gas or other fluid may occupy the pockets in the foam as it expands under lower pressure conditions, and such gas can compress under higher pressure conditions as the foam compresses. For example, the foam may be cylindrical / toroidal in shape and may be bonded (eg, glued) to the balloon / tube 40 on the inner and / or outer diameter of the cylindrical foam structure.

[0056] The compliance conduit 49 formed by the compressible / expandable tubular balloon 40 is configured to contract and expand with the cardiac cycle, mimicking the compliance of vascular tissue. The expansion and / or contraction of the inner tube / layer 41 may be facilitated by the compression of a gas and / or foam 45 disposed within the balloon chamber 42. For example, the tube 40 may be biased toward a particular shape and / or expanded state such that after blood pressure causes the gas / foam 45 to compress / deform, the expansion of the gas / foam 45 can facilitate its return to such state / shape, thereby introducing / providing compliance to facilitate blood flow within the vessel (e.g., aortic pressure).

[0057] The frame 31 may be accompanied by specific tissue fixation features such as barbs, wires, etc. For example, the distal end portion of the frame 31 may have wires or barbs with free ends that can be manipulated to be directed radially outward to puncture the tissue of the native vessel and fix the frame 31 in place. In some implementations, such wires / barbs may have shape memory that predisposes such structures to deflect radially outward when deployed from the capsule / sheath, facilitating fixation of the frame 31 to the native vessel.

[0058] The above-described device 30 may be utilized as a compliance restoration device, including at least an outer stent frame 31 and a compressible tubular balloon coupled to or within the frame 31, with a fluid conduit 49 running through the balloon 40. Such a device may have any of the features described or referenced above, including a cylindrical foam structure disposed within the tubular balloon 40, with the foam attached / glued to the balloon on the inner and / or outer diameter of the foam, or the foam may be unattached. The balloon 40 may have a circular (e.g., torus) or elliptical / oval longitudinal cross-sectional shape (e.g., cylindrical / elliptical toroid, as shown in the associated figures). The device 30 may be compressible for delivery within a catheter / sheath. The device 30 may be placed within the ascending aorta, such as immediately adjacent to the aortic valve, or at any other location in the aorta or inferior vena cava.

[0059] 7A and 7B show side cross-sectional views of the compliant implant device 30 of FIGS. 6A-6E in compressed and relaxed configurations, respectively, according to one or more embodiments. In the image of FIG. 7A, the flow channel 49 within the tubular balloon 40 is filled with blood / fluid having a fluid pressure greater than the fluid pressure of the medium 45 within the sealed chamber 42 formed around the tubular channel 49. Accordingly, the inner tube / layer 41 of the tubular balloon 40 expands radially outward, thereby compressing the fluid and / or foam 45 within the chamber 42. As the inner diameter 41 expands outward, the volume of the channel 49 increases and energy is stored in the tubular balloon 40. For example, energy may be stored within the compressed fluid 45 and / or the inner tube / layer 41, such as in the form of an elastic stretch of the material of the inner tube / layer 41. The configuration / state of the implant device 30 of FIG. 7A may be correlated with a blood pressure state associated with the systolic phase of the cardiac cycle.

[0060] In the image of FIG. 7B, the energy stored within tubular balloon 40 causes inner diameter 41 of tube 40 to contract / recoil toward its original cylindrical tubular state to reduce the fluid pressure within channel 49. That is, as the pressure gradient between channel 49 and chamber 42 decreases, gas, foam, and / or other medium 45 within chamber 42 is allowed to expand, thereby collapsing inner diameter 41, which reduces the volume of channel 49 and thereby returns the energy stored within chamber 42 and / or inner tube / layer 41 to the blood circulation. The configuration / state of implant device 30 in FIG. 7B may be associated with a blood pressure state associated with the diastolic phase of the cardiac cycle.

[0061] 8A-8E provide illustrations of a compliant implant device 130 including an elastic tube 141 according to one or more embodiments. FIGS. 9A and 9B show side cross-sectional views of the compliant implant device 130 of FIGS. 8A-8E in compressed and relaxed configurations, respectively. Similar to other embodiments disclosed herein, the device 130 can form an axial inner fluid channel 149 formed by the tube 141 configured to radially expand and retract / recoil based on changes in pressure conditions within the channel 149. The radially expandable tube 141 can be disposed about the space defined between the tube 141 and the frame 131, such that radial expansion of the tube 141, causing an increase in the volume of the channel 149, causes a corresponding decrease in the volume of the space 103. As the inner tube 141 radially expands and contracts, the volume of the channel 149 increases and decreases in a manner that provides compliance to the vessel in which it is implanted.

[0062] Inflation tube 141 may be constructed from a compliant material, such as an elastomeric polymer or other material configured to radially expand / stretch and contract / recoil in response to changing pressure / force conditions. In some embodiments, tube 141 comprises a woven structure, such as a woven shape memory alloy braided structure. In some embodiments, tube 141 comprises biological tissue.

[0063] The space 103 between the tube 141 (e.g., a polymer tube) and the frame 131 may be open on at least one axial end thereof on its outer diameter so that fluid can flow into the region / space 103 on the outer diameter of the tube 141. That is, the tube 141 may be sealed on one end 139 so that fluid is not permitted to flow between the tube 141 and the frame 131 from such side when the device 130 is implanted in a native vessel. Unlike certain other embodiments disclosed herein, the space 103 may not provide a sealed gas-filled chamber, but rather may be open in a manner that allows fluid / gas to flow into and / or out of the space 103 through one or more openings / accesses 134 on one or both axial ends / sides of the device 130. Thus, when the device 130 is implanted in a target vessel, some blood flow may be allowed to fill the space / 103 between the tube 141 and the frame 131. When tube 141 is in a relaxed, generally cylindrical state / configuration, blood may enter space 103 through one or more openings / gaps 134, penetrate space 103, and collect within space 130 until it is forced back out of device / space 103 in response to radial expansion of tube 141 in a manner that reduces the volume of space 103. If openings / accesses 134 to space 103 are on outflow end / side 133o of device 130, blood collected within space 103 may be forced back out of space 103 generally in the flow direction f of the blood circulation flow.

[0064] The compliant channel 149 is defined / formed by an expandable inner tube 141. The inner tube 141 may further function as the radial inner diameter / boundary of the blood-filled space 103. The tube 141 may be secured to the frame 131 in some manner. For example, the tube 141 may be attached to the frame and / or one or both axial ends 33 of the tube using sutures or other fastening means (e.g., one or more clips, clamps, hooks, loops, adhesives, etc.). In some embodiments, at one or both axial ends of the tube 141, the tube 141 is sewn circumferentially around the tube 141 and / or a suture structure / ring bonded to the frame 131.

[0065] The frame 131 has an expanded diameter D m (e.g., within its interior region 101), such expansion of the frame 131 within the native vessel (e.g., the aorta) may serve to expand the native vessel to some extent. For example, the diameter D m may advantageously be at least 20% larger than the diameter of the native blood vessel in the region where the frame is deployed. In some implementations, the diameter D m is 30%, 35%, 40%, 45%, or 50% larger than the diameter of the native blood vessel, and the frame 131 performs a vasodilation function when implanted / placed, thereby substantially increasing the diameter of the native blood vessel and maintaining such expansion when the implant 130 is placed / implanted in the target anatomical site.

[0066] The outer frame 131 may have any of the features of the frame 31 described above in connection with Figures 6A-6E. The outer frame 131 may have a gradually increasing diameter moving from the end 133 of the frame toward the axial center 102, as shown, which may provide reduced strain on the native vascular tissue compared to instances where the diameter of the frame is larger than the native vessel and constant along its entire length. Expansion of the frame 131 may be implemented in a gradual and atraumatic manner. For example, self-expansion or balloon expansion of the frame 131 may be performed by the native tissue to expand from its native diameter to an expanded diameter D m The implementation may be relatively slow to allow the system to adapt and respond gradually to expansion to the new system.

[0067] The implant device 130 is configured to add compliance back to an implanted target vessel, such as the aorta, to improve myocardial perfusion. The device 130 may be a percutaneously positionable implant configured to be compressed (e.g., radially compressed) and transported within a delivery catheter or other tubular delivery system. The radially expandable inner tube 141 may have a straight cylindrical shape / shape in a native, relaxed, and / or decompressed configuration / state, while in a radially expanded, pressurized configuration / state, the tube 141 may have an externally convex (e.g., internally concave) cylindrical shape that may resemble the shape of the expanded frame 131 of the device 130. The device 130 may advantageously function as an arterial flow optimizer to generate vascular compliance.

[0068] The outer frame 131 may be an expandable stent-type frame configured to radially expand from a compressed delivery configuration to an expanded state shown in FIG. 8A . To achieve this change in shape and size of the frame / stent 131, the frame 131 may have a structure including a plurality of struts forming an array of cells 135, which may have any suitable or desired shape (e.g., elliptical / oval, diamond / rhomboid, hexagonal / polygonal, etc.). The cells 135 may be arranged in any number of circumferential rows and rows in the axial or longitudinal direction A. In some embodiments, the minor axes of the cells 135 extend in the circumferential direction C and the major axes of the cells 135 extend in the axial direction A, or vice versa. In some embodiments, adjacent cells 135 are connected to each other circumferentially and / or axially by connecting struts.

[0069] The cells 135 of the frame 131 may be formed using any suitable process, such as by stamping or machining the frame structure from a metal sheet or tube. The frame 131 may be made of any at least partially rigid material, such as metal or plastic. For example, the frame may include stainless steel or nitinol. If nitinol or other shape-memory metals or materials are implemented on the frame 131, the frame may be self-expanding. In some implementations, the array of struts is formed from a sheet of metal that is rolled into a cylinder to form the tubular / cylindrical form of the frame configured for placement within a blood vessel. In some implementations, a balloon catheter can be used to expand the frame 131 for fixation to the wall of an artery or other blood vessel or body cavity.

[0070] An expandable (e.g., elastic) inner tube / channel 141 is at least partially disposed within frame 131. Inner member 141 is configured to expand at least a portion thereof outward toward frame 131 in response to a pressure gradient between blood present / flowing through axial channel 149 of inner member / tube 141 and blood 145 collected / deposited in space 103 between tube 141 and frame 131. Such pressure gradient may be at least partially due to a greater flow rate of blood within channel 149 compared to the more static blood 145 outside tube 141. Device 130 may be implanted in the ascending aorta, for example, in the region just above the aortic valve.

[0071] A radially expandable inner tube 141 disposed within a cylindrical outer stent frame 131 defines an axial blood flow path / conduit 149 therethrough. In some embodiments, the outside of the frame 131 is covered with a fabric or polymer cover 132. The stent frame 131 may be a self-expanding and / or balloon-expandable stent. The frame 131 has a diameter of 1 / 4" at its axial end D 149, as shown. e than the axial center D m The device may have a bulbous outer diameter so that it expands at a larger diameter. Such a bulbous / bulged shape may facilitate a tighter fit of the device within the target vessel into which it is implanted.

[0072] The frame 131 may advantageously have a shape that accommodates and facilitates compliant expansion of the inner tube / channel 141. For example, the inner tube 141 may have a diameter D in a relaxed (e.g., diastolic) configuration / state. t For example, the tube 141 may define a flow path 149 having a diameter D t is the diameter D of the end portion of the frame 131 e Possible exemplary values that can be deviated from while still remaining within the context of this disclosure include D t may be a value / dimension of approximately 1-2 cm, and D M may be a value / dimension between 3 and 6 cm, D emay be a value / dimension of 1.5-3 cm in some implementations.

[0073] As shown, the frame 131 may have the shape of a convex cylinder, and the diameter of the frame 131 is the axis / length L of the frame 131. f For example, as shown, the frame diameter D e may be relatively small / narrow at one or both ends 133i, 133o of the frame, with the diameter of the frame expanding to an expanded diameter D m In some embodiments, the increase in diameter moving toward the axial center 102 may be gradual and / or continuous, as in the illustrated embodiment. However, in some embodiments, the diameter of the frame may increase beyond a maximum diameter D m For example, the frame 131 may be expanded in a stepwise fashion so that the expanded diameter spans a substantial portion of the length of the frame (e.g., at least half of the length of the frame). f Narrower frame diameter D at the ends / outer parts / quarters of e Expanded frame diameter D m The inner section 101 may increase in diameter up to the length L of the frame 131. f It may amount to at least 50% of the

[0074] In some applications, the diameter D of the end portion 133 of the frame 131 e may be sized to match the diameter of the native vessel in which the frame 131 is to be deployed. For example, the diameter D of the end portion 133 of the frame 131 e may be desired to be within 20% of the diameter of the native aorta at that particular target segment. The frame 131 is advantageously configured to expand the target aortic vessel to a diameter at the axial center of the frame that is at least 20% wider than the respective aortic diameter mentioned above, while not causing rupture or excessive trauma to the native vessel wall.

[0075] The convex cylindrical shape of frame 131, when combined with the generally straight cylindrical shape / configuration of inner tube 141, may advantageously form / provide a space 103 between frame 131 and tubular channel 149 defined by inner tube 141 when tube 141 is in a relaxed configuration, wherein tube 141 can expand within space 103. Inner tube 141 can be configured to cycle between a relaxed state (wherein tube 141 is generally cylindrical or slightly convex or concave in the relaxed state) during periods of low pressure (e.g., diastole of the cardiac cycle) and a radially expanded state (wherein tube 141 radially expands / curves outward toward frame 131 within space 103 provided by expansion of the blood vessel by frame 131) during periods of high pressure (e.g., systole of the cardiac cycle). That is, the shape and dimensions of frame 131 advantageously provide space 103 within which tube / layer 141 is permitted to radially expand, which can occur within the dilated target blood vessel. By allowing compliant expansion to a diameter larger than that of the native vessel (e.g., at least 20% larger than the diameter of the native vessel prior to its expansion by the frame 131) without requiring grafting, cutting, and / or resection of the native vessel (e.g., the aorta), risks associated with vessel rupture can be reduced or eliminated. Furthermore, by expanding the vessel to allow the expansion tube 141 to be contained within the vessel, if the tube 141 leaks or ruptures in some manner, such leakage can be substantially maintained within the target vessel. Such leakage within a venous vessel can result in relatively less damage / injury to the patient compared to blood flow leakage outside the circulatory system within a body cavity. For example, rupture of the tube 141 within the target vessel may result in substantially no damage or injury to the patient.

[0076] In some embodiments, the space 103 is primarily occupied by blood 145 between the inner tube 141 and the frame 131 (and / or a polymer or other layer 144 covering the inner diameter of the frame 131), and radial expansion of the inner tube 141 causes at least a portion of the blood 145 to exit one or more openings or channels 134 on the outside of the tube 141 at the outflow (and / or inflow) end of the device 130.

[0077] Without the expansion of the native blood vessel, as achieved by the frame 131, the space available within the frame for blood flow and expansion of the inner tube / layer 141 would be limited. For example, if the frame 131 were to extend beyond the diameter D of the tubular channel 149, t If the frame has a constant diameter slightly greater than D, the inner tube 141 cannot radially expand by any significant or effective amount. Thus, the ability of the tube 141 to cyclically change volume in a manner that adds compliance to the blood circulation is limited. That is, if the frame has a constant diameter slightly greater than D, the inner tube 141 cannot radially expand by any significant or effective amount. Therefore, the ability of the tube 141 to cyclically change volume in a manner that adds compliance to the blood circulation is limited. m The convex cylindrical shape of the frame 131, having a diameter at least 20%, 30%, 40%, and / or 50% larger than the diameter of the native blood vessel, increases the ability of the inner tube 141 to add compliance to the blood circulation.

[0078] The outer frame 131 may be at least partially covered with a fabric or polymer coating or covering 132 that may promote tissue ingrowth with the inner diameter of a native blood vessel and / or provide a fluid-tight seal. The covering 132 may be disposed on an outer surface or region of the frame 131 and / or may be disposed / applied to the inner diameter of the frame 131 on its interior side. For example, a layer of covering 131 may, in some implementations, be disposed between the outer frame 131 and the tube 141. In some implementations, the covering 132 comprises a fabric or polymer sleeve that may be at least partially elastic or alternatively inelastic. The covering 132 may be applied onto and / or to the interior of the frame 131 in any suitable or desirable manner. For example, in some implementations, the covering 132 may be applied using an electro- or mechanical spinning (e.g., rotary jet spinning, electrospinning, or the like) application process, or other deposition process known to those skilled in the art.

[0079] The frame 131 may be a self-expanding and / or balloon-expandable stent frame. As described above, the frame 131 may have a spherical outer diameter, as shown, such that its diameter is substantially larger at the axial center 102 than at one or more of its axial ends 133. Such a spherical / bulged shape can facilitate a tighter fit of the device within the vessel into which it is implanted. The frame 131, as shown in the example of FIG. 6A and as described above, can include barbs or other anchors associated with its outer diameter to engage the target native vessel wall and secure the device in place. Such barbs / anchors can penetrate the outer covering / coating 132 and pierce into the native tissue to secure the frame 131 in place. In some embodiments, the distal end portion 133 of the frame 131 may have wires or barbs with free ends that can be manipulated to be directed radially outward to pierce the tissue of the native vessel and secure the frame 131 in place. In some implementations, such wires / barbs may have shape memory that predisposes such structures to deflect radially outward when deployed from the capsule / sheath, facilitating fixation of the frame 131 to the native vessel.

[0080] The compliant conduit 149 formed by the elastic tube 141 is configured to contract and expand with the cardiac cycle, mimicking the compliance of vascular tissue. The expansion and / or contraction of the inner tube 141 may be prompted by a change in the pressure gradient between the blood in the channel 149 and the blood in the space 103 outside the tube 141. For example, the tube 141 may be biased toward the relaxed cylindrical shape shown in FIG. 8A such that a decrease in the pressure gradient prompts the blood pressure in the channel 149 to cause the tube 141 to expand, thereby introducing / providing compliance to facilitate blood flow in the blood vessel (e.g., the aorta), and then returning to such a state / shape.

[0081] The implant device 130 may or may not include a layer of material 144 on the inner diameter of the frame 131. If such a layer is present, axial sealing of the space 103 may be achieved through integration or sealing of the tube 141 with the outer layer 144. Such layer 144 may comprise the same material as the tube 141 or may be integral therewith. For example, the tube 141 may provide a two-layer implementation with the outer layer 144 and the chamber 103 formed therebetween, which may be similar in some respects to the gas chamber example described above, except that the chamber 103 may have a fluid access opening / channel 134 rather than being fluid-tight as in the embodiment of FIGS. 6 and 7. The implementation of the layer 144 on the inner diameter of the frame 131 may provide protection against contact with the frame by the inner tube 141, which may cause tearing or other wear or damage. The layer 144 may provide a liner for protection or other purposes. For example, layer 144 may provide fluid-tight properties, which may be desirable in some embodiments to prevent fluid from passing from space 103 out of device 130 through the cells of frame 131 .

[0082] In the image of FIG. 9-1, the flow path 149 within the elastic tube 141 is filled with blood / fluid having a fluid pressure higher than the fluid pressure of the blood / fluid 145 disposed radially outward of the tube 141 within the space 103. Thus, as shown, the inner tube 141 expands radially outwardly, thereby reducing the volume of the space 103 between the outer diameter of the tube 141 and the frame 131 and pushing / discharging the blood / fluid 145 contained therein out of the space 103 and into the downstream circulation of the implant device 130. When the inner diameter 141 expands outwardly to the expansion diameter D te up to, the volume of the channel 149 increases and energy is stored within the tube 141. For example, the energy may be stored in the form of elastic stretching of the material of the inner tube 141. The configuration / state of the implant device 130 of FIG. 9-1 may be associated with the blood pressure state related to the systolic phase of the cardiac cycle.

[0083] In the image of FIG. 9-2, the energy stored within tube 141 causes tube 141 to contract / recoil toward its original cylindrical tubular state by decreasing the blood / fluid pressure within channel 149 relative to the pressure within blood / fluid 145 radially outside tube 141 in space 103. That is, as the pressure gradient between channel 149 and space 103 decreases, tube 141 collapses, returning the energy stored within tube 141 to the blood circulation. As tube 141 retracts / recoils into its cylindrical shape, the volume of channel 149 decreases, increasing flow through channel 149. Furthermore, as the tube contracts, the volume of space 103 between tube 141 and frame 131 increases, which may cause a vacuum effect that draws blood from within the blood vessel into space 103, as shown. Due to the different fluid dynamics of blood 145 being drawn into space 103 compared to blood circulating in channel 149, the pressure within blood 145 within space 103 may be lower than the pressure of blood within channel 149 during at least a portion of the cardiac cycle, and such a gradient may advantageously allow expansion and contraction of tube 141 to provide increased compliance as described in detail herein. The configuration / state of implant device 130 in FIG. 9-2 may be associated with blood pressure states associated with the diastolic phase of the cardiac cycle.

[0084] By including the opening / access 134 in the space 103 outside the tube 141, the pressure gradient between the space 103 and the channel 149 may be smaller than in certain other embodiments in which a completely sealed gas chamber is disposed around the flow path due to fluid communication between the blood in the channel 149 and the space 103. Accordingly, implementation of a sealed gas chamber and compliance restoration device according to aspects of the present disclosure may be preferred in some instances and / or for certain patients. However, the simplified design of the device 130 shown in FIGS. 8 and 9 may provide certain benefits that may outweigh other considerations. Furthermore, because the device 130 does not include a sealed gas chamber, risks associated with rupture and / or gas release from such a chamber may be avoided. The opening 134 into the space 103 around the tube 141 may have more features in any suitable or desirable form. For example, several sutures or connections between the tubes 141 of the frame 131 may be present at the ends where the opening / passage 134 provides access, with gaps between such sutures / connections providing access openings.

[0085] Device 130 is shown and described as having an opening in space 103 on its outflow end / side 133o. However, it should be understood that in some implementations, one or more openings may be present on inflow side 133i. In such embodiments, outflow end 133o may be sealed to prevent fluid ingress from the outflow end / side, or one or more openings may be present from the inflow 133i and outflow 133o sides into and out of space 103, and some amount of blood may flow into space 103 through the inflow and / or outflow ends and / or may be exhausted through one or both ends. In embodiments in which space 103 is sealed on outflow end 133o but at least partially open on inflow and outflow 133i, the exhaustion of blood / fluid from space 103 due to expansion of tube 141 and channel 149 may result in fluid flow from space 103 moving against the natural flow of circulation f. In some cases, such upstream flow may be desirable as a mechanism to further control / alter the flow of blood within the target vessel and / or upstream of implant 130. In such an embodiment, as tube 141 contracts / recoils, blood may be drawn from inflow end 133i into space 103, which may further alter the flow characteristics of circulation through the vessel.

[0086] 10-1, 10-2, and 10-3 show cross-sectional side views of compliant implant devices 230-1, 230-2, and 230-3 with respective flow channel configurations according to various embodiments. The flow channels of the devices shown in FIGS. 10-1, 10-2, and 10-3 may be formed by the configuration of their respective expandable / elastic tubes 241, 242, and 243, which may have any of the features of the various compliance-enhancing tubes disclosed herein.

[0087] FIG. 10-1 illustrates a compliant implant device 230-1 that includes a resilient tube 241 having a generally cylindrical / straight shape, with the diameter D of the tube 241 and the channel 249 formed thereby. t1is continuous / uniform along the length L of device 230-1 and / or tube 241, at least when tube 241 is in a relaxed / unexpanded state or configuration as shown in FIG. 10-1.

[0088] In FIG. 10-2, the tube 242 has a non-uniform diameter D along the length L of the device, at least when the tube 242 is in the relaxed / unexpanded state or configuration shown. t2 For example, the compliance-enhancing implant device 230-2 is shown with an expandable inner tube 242 having a diameter D t2 may expand in a continuous or discontinuous manner moving from inlet end 234i to outlet end 234o of device 230-2. For example, as shown, diameter D t2i is the diameter D associated with the outflow end / portion 234o t2o 2. To achieve the expanded diameter of tube 242, tube 242 may comprise a frusto-conical shape that flares outward toward outflow end 234o and / or in the direction f of flow through channel 250, as shown. The flared / expanded shape / configuration of tube 242 may affect the fluid dynamics of the circulatory flow through channel 250. For example, an increase in diameter / volume of tube 242 and channel 250 toward outflow end 234o may result in a reduction in flow velocity and / or pressure at or near outflow end 234o compared to inflow end 234i of channel 250, which may be desirable as a mechanism for controlling blood circulation flow.

[0089] In FIG. 10-3, at least when tube 243 is in the relaxed / unexpanded state or configuration as shown, the device has a non-uniform diameter D along its length L. t3 For example, the diameter D of the tube 243 and the flow channel 251 is t3 may decrease in a continuous or discontinuous manner moving from the inlet end 235i to the outlet end 235o of the device 230-3. For example, as shown, the diameter D in the region of the inlet end 235i t3iis the diameter D associated with the outflow end / portion 235o t3o To achieve the reduction in diameter of tube 243, tube 243 may comprise a frusto-conical shape that flares outward toward inflow end 235i and / or relative to the direction of flow f through channel 251, as shown. The flared / reduced shape / configuration of tube 243 may affect the fluid dynamics of the circulatory flow through channel 251. For example, the reduction in diameter / volume of tube 243 and channel 251 toward outflow end 235o may result in an increase in flow velocity and / or pressure at or near outflow end 235o relative to inflow end 235i of channel 251, which may be desirable as a mechanism for controlling blood circulation flow.

[0090] 11 illustrates a compliant implant device 330 including an inner elastic tube 341 sutured at its inflow 333i and / or outflow 333o ends to an outer frame 331, according to one or more embodiments. That is, one or more sutures, or suture loops 355, may be utilized to suture the tube 341 to the frame 331, such as directly to the end 333 of the frame 331, or a suture ring or other structure coupled to the end 333 of the frame 331. The tube 341 forms a central flow path 349.

[0091] The compliance-enhancing tubes 341 may be coupled to the frame 331 at one or both axial ends 333 of the frame 331. For example, the tubes 341 may be sutured to respective ring structures 337 at either or both axial ends 333 of the stent frame 331. If / when implemented, the ring structures 337 may be integral with the frame 331 or may be attached in some manner to one or both axial ends 333 thereof. For example, the rings 337 may be attached to the frame 331 using sutures, wires, or other attachment means 355.

[0092] The expandable tube 341 may further be sutured or otherwise secured / attached to the axial end 333 of the frame 331. For example, the tube 341 may be sutured to the suture ring 337 or other structure of the frame 331 (e.g., to the struts of the frame 331) or may be attached using adhesive or other attachment means. In some implementations, the end portion 345 of the tube 341 may be heat-bonded or otherwise sealed to the frame 331 and / or the ring 337 such that a fluid barrier exists at the interface of the tube 341 with the frame 331. In some implementations, there may be gaps between adjacent suture loops 355 that allow fluid to flow into and / or out of the space between the tube 341 and the frame 331 at their axial ends. The device 330 may have the tube 341 and frame 331 sutured / connected to only the inflow end 334i, only the outflow end 334o, both the inflow end 334i and the outflow end 334o, or either end of the device 330. The device 330 may have a cover 332 on the outside and / or inside of the frame 331 .

[0093] FIG. 12 illustrates a compliant implant device 430 including an internal elastic tube 441 with one or more circumferential inlets / outlets 434 according to one or more embodiments. The tube of material 441 may have a circumference / perimeter greater than the circumference / perimeter of the inlets or outlets 447, allowing the material of the tube to protrude inward to form the inlet / outlet channels 434. The inlets 434 may be associated with longitudinal channels 436 that run at least a portion of the length of the tube 441. For example, the inlets 434 may provide access to the longitudinal channels 436, which may allow blood to flow into and / or through the space 403 between the tube 441 and the outer frame 431. In some implementations, the blood flowing into and / or through the channels 436 comprises most or all of the blood flowing or present in the space 403 outside the tube 441. The tube 441 forms a central flow path 449.

[0094] Inlet / outlet features 434 may be formed at the inflow and / or outflow ends by suturing tube 441 around its circumference to frame 431 and / or other features of device 430, with gaps in the sutures 455 present in the area of the inlet / outlet 434 to provide gaps for flow into and / or out of such features 434. With respect to device 430, it should be understood that the illustrated features may be associated with either or both the inlet and outlet ends 433 of device 430. When feature 434 is associated with both the inlet and outlet ends 433 of device 430, blood may be permitted to flow through space 403 entering the inlet end of device 430 and exiting at its outlet. Feature 434 may permit inlet and / or outlet flow of blood into / through space 403 in a manner that reduces the risk of blood stagnation within space 403 and / or the development / formation of blood clots / emboli. 12 shows blood flow through defined channels 436 traversing the length of device 430, in some implementations such channels are not present, but rather blood flowing through features 434 into space 43 may enter circumferentially open chambers / spaces 403 not defined by longitudinal channels. Device 430 may include one or more radiopaque markers 438 to aid in visualization of the device during and / or after implantation.

[0095] 13-1 and 13-2 show diagrams of a compliant implant device 730 including a tubular structure 741, such as an elastic sleeve or balloon component, having an axial interior / central fluid channel 749 formed by the tube 741, which is configured to radially expand and retract / compress based on changing pressure conditions within the channel 749 and / or the space between the tube 741 and the outer frame 731 to which it is coupled. Blood is received within the channel 749, which may have a greater pressure than the blood in the space 703, causing the tube 741 to expand radially outward, thereby forcing blood out of the space 703.

[0096] The elastic sleeve 741 can be attached to the frame 731 at either or both of the upstream end 733i and downstream end 733o of the frame. The implant device 730 can be deployed within the aorta 705, such as within the descending aorta, or within any other vessel segment. The middle / inner portion 701 of the stent / frame 731 is configured to expand away from the sleeve / tube 741, thereby pressing radially outward against the vessel (e.g., aortic) wall, thereby creating a space 703 between the vessel wall 705 (and stent / frame 731) and the sleeve / tube 741. Attachment of the sleeve / tube 741 to the stent / frame 731 at the end of the implant 730 can seal the sleeve / tube 741 to the vessel, such as by pressing the sleeve / tube 741 against the vessel wall 705.

[0097] For example, during ventricular systole, the sleeve / tube 741 can expand outward toward the stent / frame 731 and vessel wall 705, and the sleeve / tube 741 can elastically contract radially inward, for example, during ventricular diastole, thereby simulating a compliant, healthy vasculature. Delivery of the implant device 730 to the target anatomy can be via, for example, transfemoral or other transcatheter access.

[0098] The space 703 defined between the tube 741 and the frame 731 can provide an area for radial expansion of the tube 741, which causes an increase in the volume of the channel 749. As the volume of the channel 749 increases, the volume of the space 703 decreases, as shown by comparing Figures 13-1 and 13-2. The radial expansion and contraction of the tube 741 increases and decreases the volume of the channel 749 in such a way as to provide compliance characteristics to the blood vessel 705 in which it is implanted.

[0099] Inflation tube 741 may be constructed from a compliant material, such as an elastomeric polymer or other material configured to radially expand and contract / recoil in response to changing pressure / force conditions. In some embodiments, tube 741 comprises a woven structure, such as a woven shape memory alloy braided structure. In some embodiments, tube 741 comprises biological tissue.

[0100] The space 703 between the tube 741 (e.g., a polymer tube) and the frame 731 may be open on at least one axial end thereof to allow fluid to enter or exit the region / space 703 on the outer diameter of the tube 741. Such openings 739 may comprise holes or other openings in the tube 741 in the region of the upstream / inflow or downstream / outflow axial ends 739 of the tube 741. That is, the tube 741 may be coupled on one or both axial ends 739 to the respective ends 739 of the frame 731, and fluid flow to and / or from the space 703 is prevented or inhibited except through the openings 739. In some embodiments, the tube 741 does not include openings, but rather a compressible gas or fluid is maintained within the space 703 in such a way that it stores energy when compressed due to the expansion of the tube 741 and returns energy to circulation as the pressure in the channel 749 decreases and the medium disposed in the space 703 expands.

[0101] In some implementations, when the device 730 is implanted in the target vessel 705, some blood flow may be angled to fill the space 703 between the tube 741 and the frame 731. Such fluid passages into and out of the space 703 may be through apertures or other openings 739 in the tube 741. Additionally or alternatively, fluid ingress / egress may be through open cells in the frame 731 outside the device 730, such as in an area radially outward of the bond of the tube 741 to the frame 731, between the inner diameter of the vessel wall 705 and the outer diameter of the frame 731, radially outward of the tube 741 and / or at its distal end 743. For example, at least one of the ends 733 of the frame 731 may have a diameter smaller than the diameter of the native vessel 705, such that a space between the end of the frame 733 and the native vessel is formed at one or more axial ends of the frame 731. When tube 741 transitions to a relaxed, generally cylindrical state / configuration, as shown in FIG. 13-1 , blood may enter space 703 through one or more openings / gaps 739, 734 and collect within space 703 until it is forced back out of the device / space 703 in response to radial expansion of tube 741 in a manner that encroaches on and reduces the volume of space 703, as shown in FIG. 13-2. If opening / access 739 to space 703 is at the outflow end / side of device 730, blood collected in space 703 may be forced back out of space 703 generally in the flow direction f of the blood circulation flow.

[0102] Frame 731 is approximately 10-15cm long or more. f The tube / balloon 741 may be relatively narrow, e.g., a relaxed diameter D of the tube 741 in the interior region 701. t is the diameter D of the end of the frame 731 in the area just outside the device 730 e and / or the diameter D of the native blood vessel 705 v For example, the diameter D t is the diameter of the blood vessel, D e and / or diameter D v The diameter of the tube D may be at least 20% smaller than tmay be 10 to 15 mm, such as 8 to 12 mm. t The stent diameter D of at least the inner region 701 is about 10 mm. m is the diameter D of the tube 741 in the expanded configuration of the frame 731 shown, such as 15-25 mm. t For example, the expanded diameter D of the frame 731 may be substantially larger than m The high pressure condition reduces the diameter of the tube 741 in at least the inner region 701 to a diameter D m (e.g., up to 20 mm), D t and D m The expanded diameter D of the frame 731 can be increased to a dimension between m can function to secure the device 730 in place within the vessel and provide expansion space 703.

[0103] The compliant channel 749 is defined / formed by an expandable inner tube 741. The inner tube 741 may further serve as the radial inner diameter / boundary of the space 703. The tube 741 may be secured to the frame 731 in some manner. For example, the tube 741 may be attached to the frame and / or one or both of the axial ends 733 / 743 of the tube using sutures or other fastening means (e.g., one or more clips, clamps, hooks, loops, rings, adhesives, heat bonds, etc.). In some embodiments, on one or both axial ends of the tube 741, the tube 741 is circumferentially sewn around the tube 741 to the frame 731 and / or a suture structure / ring bonded to the frame 731 and / or the tube 741. The tube 741 may advantageously have a length that is longer than the expanded length of the frame 731, such that the end / lip / puff 747 of the tube 741 may curl over / around the end 733 of the frame as shown and be secured to the frame 731 in such a configuration. For example, an O-ring or similar device may be placed and secured over the lip / cuff 747 of the tube 741 around the end 733 of the frame 731 and may be clamped and / or crimped in such position to secure the tube 741 to the frame 731. Such bonding of the tube 741 to the frame 731 using the cuff 747 of the tube 741 may improve the bond and / or seal between the frame 731 and the tube 741.

[0104] The frame 731 has an expanded diameter D (e.g., at its inner region 701). m Such expansion of the frame 731 within the native vessel 705 (e.g., the aorta) may serve to expand the native vessel to some extent. For example, the frame diameter D m may advantageously be at least 20% larger than the diameter of the native blood vessel 705 in the region where the frame 731 is deployed. In some implementations, the diameter D m is the diameter D of natural blood vessels 705 v25%, 30%, 35%, 40%, 45%, or 50% larger than the target anatomical site, and frame 731 performs a vasodilation function when implanted / deployed, thereby substantially increasing the diameter of the native blood vessel and maintaining such expansion when implant 730 is positioned / implanted at the target anatomical site.

[0105] The outer frame 731 may have a gradually increasing diameter moving from the ends 733 of the frame toward the axial center 702, as shown, which allows the diameter of the frame to be larger than the natural blood vessel and extend its entire length L f 13-1 , the frame 731 in the expanded configuration has a stepped diameter, with the diameter of the frame varying from a narrow diameter D at both ends 733 to a narrow diameter D at both ends 733. e , the expanded diameter D of the intermediate segment 701 relatively close to both ends 733 m , for example, within the first 20-30% of the length of the frame 731 (e.g., the last quarter of the length) from both ends toward the center 702. e The narrowing of the tubing 741 can advantageously provide a relatively narrow portion of the frame for securing the axial end 743 of the tube 741 and can also provide a more gradual expansion / diastole of the blood vessel that is less traumatic to the blood vessel.

[0106] The expansion of frame 731 can be implemented in a gradual and atraumatic manner. For example, self-expansion or balloon expansion of frame 731 allows the natural tissue to expand to its natural diameter D v Expanded diameter D m The implementation may be relatively slow to allow the system to adapt and respond gradually to expansion to the new system.

[0107] Device 730 may be a percutaneously positionable implant configured to be compressed (e.g., radially compressed) and transported within a delivery catheter or other tubular delivery system. The radially expandable inner tube 741 may have a straight cylindrical shape / form in a native, relaxed, and / or decompressed configuration / state, while in a radially expanded, pressurized configuration / state, tube 741 may have an externally convex (e.g., internally concave), axially bulging cylindrical shape that may resemble the shape of the expanded frame 731 of device 730 and conform to it as it expands. Device 730 may advantageously function as an arterial flow optimizer to generate vascular compliance.

[0108] The outer frame 731 may be an expandable stent-type frame configured to radially expand from a compressed delivery configuration to an expanded state shown in FIGS. 13-1 and 13-2. To achieve this change in shape and size of the frame / abutment 731, the frame 731 may have a structure including a plurality of struts forming an array of cells 735, which may have any suitable or desired shape (e.g., elliptical / oval, diamond / rhomboid, hexagonal / polygonal, etc.). The cells 735 may be arranged in any number of circumferential rows and axial or longitudinal rows in the direction A. In some embodiments, the minor axes of the cells 735 extend in the circumferential direction and the major axes of the cells 735 extend in the axial direction A, or vice versa. In some embodiments, adjacent cells 735 are connected to one another circumferentially and / or axially by connecting struts 736.

[0109] The cells 735 of the frame 731 may be formed using any suitable process, such as by stamping or machining the frame structure from a sheet or tube of metal. The frame 731 may be made of any at least partially rigid material, such as metal or plastic. For example, the frame may include stainless steel or nitinol. If nitinol or other shape-memory metals or materials are implemented on the frame 735, the frame may be self-expanding. In some implementations, the array of struts is formed from a sheet of metal that is rolled into a cylinder to form the tubular / cylindrical form of the frame configured for placement within a blood vessel. In some implementations, a balloon catheter can be used to expand the frame 731 for fixation to the wall of an artery or other blood vessel or body cavity.

[0110] An expandable (e.g., elastic) inner tube / channel 741 is at least partially disposed within the frame 731. The inner member 741 is configured to expand at least a portion thereof outward toward the frame 731 in response to a pressure gradient between blood present / flowing through the axial channel 749 of the inner member / tube 741 and blood or other medium 745 collecting / disposed within the space 703 between the tube 741 and the frame 731. Such a pressure gradient may be at least partially due to a greater flow rate of blood within the channel 749 compared to the more static blood / medium 745 outside the tube 741. The device 730 may be implanted, for example, in the ascending aorta, e.g., in the region just above the aortic valve, or in the thoracic or abdominal aorta.

[0111] A radially expandable inner tube 741 disposed within a cylindrical outer stent frame 731 defines an axial blood flow path / conduit 749 therethrough. In some embodiments, the outside of the frame 735 is covered with a fabric or polymer cover. The stent frame 735 may be a self-expanding and / or balloon-expandable stent. The frame 735 has a diameter greater at its axial center D than at its axial ends D, as shown. m705. The device may have an axially bulging / bulging outer diameter such that it expands at a larger diameter. Such a bulging / bulging shape may facilitate a tighter fit of the device within the target vessel 705 into which it is implanted.

[0112] The frame 731 may advantageously have a shape that accommodates and facilitates compliant expansion of the inner tube / channel 741. For example, the inner tube 741 may have a diameter D in a relaxed (e.g., diastolic) configuration / state. t For example, the tube 741 may define a flow path 749 having a diameter D t is the diameter D of the end portion 733 of the frame 731 e or may be approximately equal to the diameter D of the tube 741 t is the diameter D of the end portion 733 of the frame 731 e Possible exemplary values that can be deviated from while still remaining within the context of this disclosure include D t may be a value / dimension of approximately 0.5-2 cm, and D m may be a value / dimension between 3 and 6 cm, D e may be a value / dimension of 1.5-3 cm in some implementations.

[0113] As shown, the frame 731 may have the shape of a convex cylinder, and the diameter of the frame 731 is the axis / length L of the frame 731. f and / or over at least a portion of the inner section 701. f For example, as shown, the frame diameter D e may be relatively small / narrow at one or both ends 733i, 733o of the frame, with the diameter of the frame expanding to a diameter D m In some embodiments, the diameter of the frame 731 may be increased to a maximum diameter D m is the frame length L fFor example, the frame 731 may be expanded in a stepwise manner to cover a substantial portion of the length L of the frame 731 (e.g., at least half of the length of the frame) such that the expanded diameter spans the inner section 701 of the frame. f At the ends / quartiles of the narrower frame diameter D e Expanded frame diameter D m However, in some embodiments, the increase in diameter moving toward axial center 702 may be gradual and / or continuous.

[0114] In some applications, the diameter D of the end portion 733 of the frame 731 e is the diameter D of the native blood vessel in which the frame 731 is deployed. v For example, the diameter D of the end portion 733 of the frame 731 may be e is the diameter D of the native aorta 705 at that particular target segment v It may be desirable for the diameter to be within 20% of the aortic diameter. Depending on the particular aortic segment in which the device 730 is implanted, the frame 731 is advantageously configured to expand the target vessel (e.g., the aorta) 705 to a diameter at the axial center 702 of the frame 731 that is 20% larger than the respective aortic diameter as described above, while not causing rupture or excessive trauma to the native vessel wall.

[0115] The bulging / convex cylindrical shape of frame 731, when combined with the generally straight cylindrical shape / configuration of inner tube 741, may advantageously provide a space 703 between frame 731 and tubular channel 749 defined by inner tube 741 when tube 741 is in a relaxed configuration, and tube 741 may expand radially within space 703. Inner tube 741 may be configured to cycle between a relaxed state (tube 741 is generally cylindrical or slightly convex or concave in the relaxed state) during periods of low pressure (e.g., diastole of the cardiac cycle) and a radially expanded state (tube 741 expands / curves radially outward toward frame 731 within space 703 provided by the expansion of the blood vessel by frame 731) during periods of high pressure (e.g., systole of the cardiac cycle). That is, the shape and dimensions of the frame 731 advantageously provide space 703 that permits radial expansion of the tube / layer 741, and such expansion may occur within the expanded target vessel. By allowing compliant expansion to a diameter larger than that of the native vessel (e.g., at least 20% larger than the diameter of the native vessel prior to its expansion by the frame 731) without requiring grafting, cutting, and / or resection of the native vessel (e.g., the aorta), risks associated with vessel rupture may be reduced or eliminated. Furthermore, by expanding the vessel to allow the expansion tube 741 to be contained within the vessel, if the tube 741 leaks or ruptures in some manner, such leakage may be substantially contained within the target vessel. Such a rupture within a venous vessel may result in relatively less damage / injury to the patient compared to a rupture that causes leakage of blood flow outside the circulatory system within a body cavity. For example, a rupture within the target vessel 705 may result in substantially no damage or injury to the patient.

[0116] In some embodiments, the space 703 is primarily occupied by blood 745 between the inner tube 741 and the frame 731 (and / or a polymer or other layer 744 covering the inner diameter of the frame 731). In some embodiments, radial expansion of the inner tube 741 causes at least a portion of the blood 745 to exit from one or more openings or channels 739 on the outside of the tube 741 at the outflow end of the device 730.

[0117] Without the expansion of the native blood vessel, as achieved by the frame 731, the space available within the frame for blood flow and expansion of the inner tube / layer 741 would be limited. For example, if the frame 731 were to expand the diameter D of the tubular channel 749, t and / or the diameter D of the blood vessel 705 v If the frame has a constant diameter slightly greater than D, the inner tube 741 cannot radially expand by a significant or effective amount. Thus, the ability of the tube 741 to cyclically change volume in a manner that adds compliance to the blood circulation is limited. That is, if the frame has a constant diameter slightly greater than D, the inner tube 741 cannot radially expand by a significant or effective amount. Therefore, the ability of the tube 741 to cyclically change volume in a manner that adds compliance to the blood circulation is limited. m The axial bulge / convex cylindrical shape of the frame 731, having a diameter at least 20%, 30%, 40%, and / or 50% larger than the diameter of the native blood vessel, increases the ability of the inner tube 741 to add compliance to the blood circulation.

[0118] The outer frame 731 may be at least partially covered with a fabric or polymer coating or covering that may promote tissue ingrowth with the inner diameter of a native blood vessel and / or provide a fluid-tight seal. The covering may be disposed on an outer surface or region of the frame 731 and / or disposed / applied to the inner diameter of the frame 731 on its interior side. For example, a layer of coating may, in some implementations, be disposed between the outer frame 731 and the tube 741. In some implementations, such a covering comprises a fabric or polymer sleeve that may be at least partially elastic or alternatively inelastic. The covering may be applied onto or within the frame 731 in any suitable or desirable manner. For example, in some implementations, the covering may be applied using an electro- or mechanical spinning (e.g., rotary jet spinning, electrospinning, or the like) application process, or other deposition process known to those skilled in the art.

[0119] The frame 731 may be a self-expanding and / or balloon-expandable stent frame. As described above, the frame 731 may have a bulbous outer diameter, as shown, such that its diameter is substantially larger at its axial center than at one or more of its axial ends. Such a bulbous / bulged shape can facilitate a tighter fit of the device within the vessel into which it is implanted. The frame 731 may include barbs, spikes, or other anchors on its outer diameter configured to engage the target native vessel wall and secure the device in place. Such barbs / anchors may penetrate through the outer covering / coating and into the native tissue to secure the frame 731 in place. In some embodiments, the distal end portion 733 of the frame 731 may have wires or barbs with free ends that can be manipulated to be directed radially outward to puncture the tissue of the native vessel 705 and secure the frame 731 in place. In some implementations, such wires / barbs may have shape memory that predisposes such structures to deflect radially outward when deployed from the capsule / sheath, facilitating fixation of the frame 731 to the native vessel.

[0120] The compliant conduit 749 formed by the elastic tube 741 is configured to contract and expand as the heartbeat cycles, mimicking the compliance of healthy, natural vascular tissue. The expansion and / or contraction of the inner tube 741 can be prompted by a change in pressure gradient between the blood in the channel 749 and the blood / media 745 in the space 703 outside the tube 741. For example, the tube 741 can be biased toward the relaxed cylindrical shape shown in FIG. 13-1 such that a decrease in the pressure gradient prompts the tube 741 to return to such a state / shape after blood pressure inside the channel 749 causes the tube 741 to expand (see FIG. 13-2), thereby introducing / providing compliance to facilitate blood flow within the blood vessel 705 (e.g., the aorta).

[0121] The implant device 730 may or may not include a layer of material on / against the inner diameter of the frame 731. If such a layer is present, axial sealing of the space 703 may be accomplished through integration or sealing with / to the outer layer of the tube 741. Such a layer may comprise the same material as the tube 741 or may be integral therewith. For example, the tube 741 may provide a two-layer implementation with the chamber 703 formed therebetween along with the outer layer 744, which may be similar in some respects to the gas chamber example described above and elsewhere, except that the chamber 703 is not fluid-tight as in the embodiments of FIGS. 6 and 7 and may or may not have fluid access openings / channels. The implementation of the layer 744 on the inner diameter of the frame 731 may provide protection against contact with the frame by the inner tube 741, which may cause tearing or other wear or damage. The layer 744 may provide a liner for protection or other purposes. For example, the layer can provide fluid-tight properties, which in some embodiments may be desirable to prevent fluid from passing from the space 703 through the frame 731 and out of the device 730.

[0122] In the image of FIG. 13-2, the flow path 749 within the elastic tube 741 is filled with blood / fluid having a fluid pressure greater than the fluid pressure of the blood / medium 745 disposed radially outside the tube 741 formed around the tubular channel 49. Thus, as shown, the inner tube 741 expands radially outward, thereby reducing the volume of the space 703 between the outer diameter of the tube 741 and the frame 731. If the outflow end opening / opening 739 is implemented, the fluid / blood disposed within the space 703 is forced / exhausted from the space 703 and enters the circulation downstream of the implant device 730. As the inner diameter 741 expands outward, the volume of the channel 749 increases, and energy is stored within the tube 741. For example, the energy may be stored in the form of an elastic stretch of the material of the inner tube 741. The configuration / state of the implant device 730 in FIG. 13-2 may be associated with a blood pressure state associated with the systolic phase of the cardiac cycle.

[0123] In the image of FIG. 13-1, the energy stored within tube 741 contracts / recoils toward its original cylindrical tubular state by reducing the blood / fluid pressure within channel 749 relative to the pressure within blood / medium 745 radially outside tube 741 in space 703, thereby providing a secondary pulse during circulation. That is, as the pressure gradient between channel 749 and space 703 decreases, tube 741 contracts, returning the energy stored within tube 741 to the blood circulation. As tube 741 retracts / returns to the cylindrical shape shown in FIG. 13-1, the volume of channel 749 decreases, increasing flow through channel 749. Furthermore, in some implementations, as the tube contracts, the volume of space 703 between tube 741 and frame 731 increases, which can cause a vacuum effect that draws blood from within blood vessel 705 into space 703, as shown. Due to the different fluid dynamics of blood 745 being drawn / pulled into space 703 compared to blood circulating in channel 749, the pressure of blood 745 in space 103 may be lower than the pressure of blood in channel 749 during at least a portion of the cardiac cycle, and such a gradient may advantageously allow expansion and contraction of tube 741 to provide increased compliance as described in detail herein. The configuration / state of implant device 730 of FIG. 13-1 may be associated with blood pressure states associated with the diastolic phase of the cardiac cycle.

[0124] By including the opening / access 739 in the space 703 outside the tube 741, the pressure gradient between the space 703 and the channel 749 may be smaller than in certain other embodiments in which a completely sealed gas chamber is disposed around the flow path due to fluid communication between the blood in the channel 749 and the blood 745 in the space 703. Accordingly, implementation of a sealed gas chamber and compliance restoration device according to aspects of the present disclosure may be preferred in some instances and / or for certain patients, and the implant device 730 of FIGS. 13-1 and 13-2 may be implemented with a sealed gas chamber on the outer diameter of the tube 741. However, the simplified design of the device 730 shown in FIGS. 13-1 and 13-2 with fluid communication between the space 703 and the circulation within the blood vessel 705 may provide certain benefits that may outweigh other considerations. Furthermore, in implementations in which the device 730 does not include a sealed gas chamber, risks associated with rupture and / or gas release from such a chamber may be avoided. As mentioned above, device 730 may be implemented using a fluid-tight compressible gas / fluid chamber between tube 741 and frame 731. Opening 739 into space 703 around tube 741 may have more features in any suitable or desirable form. For example, a number of sutures or connections between tube 741 and frame 731 may be present on one or both ends, with gaps between such sutures / connections providing access openings into and out of space 703.

[0125] Device 730 is shown and described as having an opening in space 703 on its outflow end / side 733o. However, it should be understood that in some implementations, one or more openings may be present on the inflow side 733i. In such embodiments, the outflow end 733o may be sealed to prevent fluid ingress from the outflow end / side, or one or more openings may be present from the inflow end / side 733i and outflow end / side 733o into and out of space 703, and some amount of blood may enter space 703 through the inflow and / or outflow ends and / or exit through one or both ends. In embodiments in which space 703 is sealed on the outflow end 733o but at least partially open on the inflow end 733i, the evacuation of blood / fluid from the space due to expansion of tube 741 and channel 749 may result in a flow of fluid from space 703 moving against the natural flow of circulation f. In some cases, such upstream flow may be desirable as a mechanism to further control / alter the flow of blood within the target vessel and / or upstream of implant 730. In such an embodiment, as tube 741 contracts / recoils, blood may be drawn from inflow end 733i into space 703, which may further alter the flow characteristics of circulation through the vessel.

[0126] 14-1, 14-2, and 14-3 illustrate a flow diagram of a process 500 for implanting a compliance implant device 530 according to one or more embodiments. FIGS. 15-1, 15-2, and 15-3 illustrate images of the compliance implant device 530 and certain anatomical structures corresponding to the operations of the process 500 of FIGS. 14-1, 14-2, and 14-3, according to one or more examples. The process 500 utilizes a transcatheter procedure for implantation / deployment of a compliance-enhancing implant device according to aspects of the present disclosure. However, it should be understood that the implant devices disclosed herein may be implanted using other types of minimally invasive and / or surgical procedures.

[0127] At block 502, the process 500 involves advancing a guidewire 550 through at least a portion of the patient's aorta 16 to reach a target implantation site 501. For example, image 602 shows an exemplary implantation site 501a in the abdominal aorta 15, exemplary implantation sites 501b, 501c in the descending thoracic aorta 14, an exemplary implantation site 501d in the aortic arch 13, and an exemplary implantation site 501e in the ascending aorta 12, such as in the region of the aortic valve 7. The guidewire 550 may be advanced through the aortic valve 7 or to any point along the path of the aorta 16. Access to the aorta 16 may be achieved through any suitable vascular puncture that provides access to the arterial system. For example, access may be achieved via the femoral artery or other arterial vessel. In some implementations, access to the inferior vena cava is gained via the femoral vein or other access, and a guidewire and / or other instrument may be crossed into the abdominal aorta 15 in the region where the inferior vena cava and abdominal aorta 15 abut one another by puncturing the venous and arterial walls and advancing through such puncture openings. While the process 500 and certain other embodiments are described herein in the context of implantation within the aorta 16, it should be understood that the compliance-enhancing device of the present disclosure may be implanted in other arterial or venous vessels, such as the inferior vena cava 19 (see FIG. 1 ).

[0128] Although the process 500 and accompanying figures are presented with respect to the implantation of a single compliance-enhancing implant device 530, it should be understood that the process 500 may involve implanting multiple compliance-enhancing implant devices at various locations within the aorta 16 or other blood vessel.

[0129] At block 504, the process 500 involves providing a delivery system 100 having a compliance-enhanced implant device 530 disposed in a distal portion thereof. Image 603 of FIG. 15-1 illustrates a cross-sectional view of the delivery system 100 in accordance with one or more exemplary embodiments of the present disclosure. The delivery system 100 may include one or more catheters or sheaths used to advance and / or implant the compliance-enhanced implant device 530, which may be at least partially disposed within the delivery system 100 during a portion of the process 500. The compliance-enhanced implant device 530 may be positioned within the delivery system 100 with its first end (e.g., inflow end 533i) disposed distally and its second end (e.g., outflow end 533o) disposed proximally relative to the illustrated orientation of the delivery system 100.

[0130] In some embodiments, the delivery system 100 comprises an outer catheter or shaft 540 that can be used to transport the compliance-enhanced implant device 530 to a target implantation site. That is, the compliance-enhanced implant device 530 is advanced at least partially within the lumen of the outer shaft 540 to the target implantation site such that the compliance-enhanced implant device 530 is held and / or secured in an at least partially radially compressed configuration within the distal portion of the outer shaft 540.

[0131] In some embodiments, the delivery system 100 includes a tapered nosecone feature 548 that facilitates advancing the distal end of the delivery system 100 through a patient's tortuous anatomy and / or an outer delivery sheath or other conduit / pathway. The nosecone 548 may be a separate component from the outer shaft 540 or may be integral with the outer shaft 540. In some embodiments, the nosecone 548 is adjacent to and / or integral with the distal end of the outer shaft 540. In some embodiments, the nosecone 548 is distally tapered to a generally conical shape and may include and / or form a multiple flap-type feature that can be spread apart as the compliance-enhancing implant device 530 and / or portions thereof, the inner shaft, or the device is advanced distally.

[0132] The delivery system 100 may be further configured to have a guidewire 550 at least partially disposed within and / or coupled to it in a manner that allows the delivery system 100 to follow a path defined by the guidewire 550. In some implementations, the guidewire 550 may pass inside the implant device 530 and / or through a lumen of a pusher device or tube 542 of the delivery system 100.

[0133] The compliance-enhancing implant device 530 may have any one or more features of any of the embodiments detailed herein, including an outer frame 531 and an inner radially expandable tube 541, which may or may not include a compressible gas-filled chamber disposed therearound, and which may be at least partially sealed to the frame 531 at one or both axial ends. The implant device 530 may be disposed within the shaft / sheath 540 in a radially compressed / collapsed configuration, with the frame 531 and / or the tube 541 being crimped / crimped to assume a reduced radial profile. In the compressed delivery configuration, the device 530 may be somewhat elongated compared to its fully expanded configuration due to at least some of the struts / cells of the frame 531 being biased to a more longitudinally oriented configuration when radially crimped / compressed.

[0134] The delivery system 100 may optionally include a pusher shaft 542, as shown, which may be slidably disposed within the outer sheath 540 proximal and / or adjacent to the implant device 530. The pusher 542 may be configured to be used to push / advance the frame 531 and / or other components of the implant device 530 relative to the outer shaft / sheath 540 as a means of deploying the apparatus 530 from the sheath 540. For example, the pusher 542 may be advanced distally relative to the outer sheath 540 to cause distal advancement of the compliance-enhancing implant device 530 through a distal opening in the outer sheath / shaft 540. Alternatively (or additionally), the implant device 530 may be at least partially deployed from the outer sheath 540 by pulling the outer sheath 540 proximally relative to the pusher 542.

[0135] In some embodiments, the pusher 542 may be removably attached to the frame 531 and / or other components of the implant device 530, and after the device 530 is deployed from the sheath 540, positioned at the desired implantation site / location, and / or expanded, the pusher 542 (or other components of the delivery system 100) may be disengaged from the implant device 530 to release the device 530 and allow removal / withdrawal of the delivery system 100. For example, the pusher 542 or other components of the delivery system 100 may include one or more legs or arms that protrude distally and / or radially from the pusher. In some implementations, to deploy the implant device 530, the outer sheath 540 is pulled proximally and / or the pusher 542 is pushed distally, thereby passing the sheath 540 over the distal end 533i of the implant device 530 and at least partially exposing / deploying the frame 531 and implant device 530. Initially, the sheath 540 may be retracted only to a position exposing a portion of the frame 531 and / or other portions of the apparatus 530, with further retraction of the sheath 540 while maintaining position and retention around the linking arms associated with the pusher 542 occurring after the position of the implant device 530 in the anatomy is confirmed, and withdrawal of the sheath 540 proximally past the linking arms of the pusher 542 disengages the arms from the frame 531 and / or apparatus 530 in a manner that radially deflects them, thereby releasing the device. In some embodiments, such linking arms are not associated with the pusher 542. The implant device 530 may include one or more radiopaque markers that can be referenced to determine / confirm the position of the implant device 530 at various stages of the process 500 using an appropriate imaging modality.

[0136] Image 605 shows an alternative delivery system 505 including a distal capsule portion 515, with an implant device 530 disposed in a compressed configuration within the capsule portion 515. Deployment of the implant device 530 may be performed at least in part by pulling the capsule sheath 545 proximally, such that the implant device 530 is pushed proximally relative to a pusher 542 to maintain the implant 530 in place while being unsheathed. In some implementations, the capsule portion 515 may have a diameter greater than the diameter of the sheath 540 in a region proximal to the capsule 515.

[0137] At block 506, the process 500 involves advancing the delivery system 100 over the guidewire 550 until the target implantation site is reached, thereby positioning the implant device 530 for deployment within the target anatomical structure. At block 508, the process 500 involves deploying the implant device 530 from the delivery system 100, which may be performed in any of the ways described above. Once the device 530 is deployed from the delivery system 100, at block 510, the process 500 may involve expanding the frame 531 and / or tube 541 of the implant device 530, thereby securing the implant 530 in its deployed / expanded configuration. The expansion operation associated with block 508 may further involve expanding the native vessel by expanding the frame 531 to a diameter, at least for a lengthwise portion thereof, that is substantially larger (e.g., 20-30% larger than the diameter of the native vessel), and such expansion of the vessel may serve to form / introduce space for radial expansion of the duct 541 and / or one or more portions / layers thereof, as described in detail herein.

[0138] The device 530 may be mounted on the balloon 606 of the delivery shaft 604. The device 530 may be positioned on the balloon 606 such that the inflow end 533i is disposed distally on the balloon 606 and the outflow end 533o is disposed proximally on the balloon 606. When the balloon 606 is inflated, the frame 531 expands around the balloon 606. The balloon 606 may function to expand the struts of the frame 531 by expanding the inner tube 541 within the frame 531 and pushing outward against the frame 531. In embodiments where the inner tube 541 is part of a tubular member that includes a compressible gas-filled chamber, the gas within the chamber may compress to some extent during expansion of the balloon 606, but may also exert an outward radial force on the frame 531, causing its expansion, as described in detail above. In embodiments that do not include a gas-filled chamber on the outside of the inner tube 541, the inner tube 541 may expand and push against the inner diameter of the frame 531, expanding the frame. A layer of coating, fabric, or other coating / layer may be placed between inner tube 541 and frame 531 , and such layer may line the inner diameter of frame 531 .

[0139] In some implementations, the frame 531 can be expanded / expanded using a pull wire configured to be pulled or pushed to expand the frame to the expanded configuration shown. For example, the pull wire can be coupled to a distal portion of the frame 531 such that pulling the wire proximally brings the ends of the frame 531 together, thereby expanding / expanding the frame 531. In some implementations, the expansion of the frame 531 can be achieved through a shape memory feature of the frame 531. For example, the frame 531 can include nitinol or other shape memory metal configured to self-expand when released from a delivery sheath / capsule.

[0140] The balloon 606 may be configured to expand in an axially curved, rounded / spherical shape that matches the convex / curved cylindrical shape of the frame 531. After the balloon 606 expands the frame 531 into the convex / curved cylindrical shape to dilate the vessel, the balloon 606 can be deflated and removed. Controlling the position of the compliant implant device 530 on the balloon 606 can be important during delivery, given possible longitudinal shortening of the frame 531 during expansion, which may cause the device 530 to move relative to the balloon 606. In some implementations, the mid-portion 514 of the device / frame 531, which may be configured to expand to the widest diameter of the length of the frame 531, may remain constant relative to the balloon, while the inflow and outflow end portions 533 may shorten somewhat toward the mid-portion 514 during expansion.

[0141] At block 512, the process 500 involves withdrawing the delivery system 100 and guidewire 550, leaving the implant device 530 implanted in the aorta or other target vessel, as shown in image 610. As shown, with the implant device 530 implanted, the increased compliance provided by the implant device 530 may improve arterial blood flow and / or prevent elevated blood pressure. Other benefits may also be achieved, as described in detail herein.

[0142] 16-1 and 16-2 illustrate the compliance-enhancing effect of the implant device 530 described above during high-pressure (e.g., systole) and low-pressure (e.g., diastole) stages / conditions, respectively. As shown in FIG. 16-1, when blood is received within the channel 549 of the expandable tube 541 at a pressure greater than the pressure immediately outside the tube 541, the tube / layer 541 may expand into the space 503 provided outside the tube 541 due to the expansion of the frame 531 and the blood vessel. This expansion into the space 503 results in the expansion of the tube 541 resulting in energy stored within the tube 541 and / or compressed gas outside the tube 541. That is, the elastic recoil characteristics of the tube 541 and / or the expansion energy of the compressed gas (not shown in FIGS. 16-1 and 16-2) disposed around the tube 541 may increase in response to the radial expansion of the tube 541. The expansion of tube 541 serves to at least partially increase the volume of channel 549 and reduce the pressure within channel 549 during high pressure phases.

[0143] 16-2, when the pressure within channel 549 decreases relative to the pressure radially outside of tube 541, the energy stored within tube 541 and / or the compressed gas may return to the blood circulation by decreasing the volume of channel 549 and increasing the pressure therein to some extent, thereby pushing blood through channel 549 and out of outflow end 533o of device 530. This volume decrease and pressure increase occurs in response to the recoil / contraction of tube 541 into the cylindrical shape / configuration shown.

[0144] Valve-integrated compliance-enhanced implant In some implementations, examples of the present disclosure provide a compliance-enhancing radially expandable tube as well as an implant including prosthetic valve functionality, where such a device is configured to function as a vascular flow optimization / augmentation device configured to generate vascular compliance, and may further serve to provide replacement of a diseased heart valve (e.g., an aortic valve) and / or otherwise advantageously provide unidirectional flow control.

[0145] 17A-17C provide a side view, a side cross-sectional view, and an axial view, respectively, of a valved compliance implant device 800 according to one or more embodiments. Device 800 may be utilized as an arterial flow optimizer. Device 800 may include a compliance-enhancing segment / portion 830, which may be axially offset from a valved segment / portion 850, where compliance-enhancing segment 830 and valved segment 850 cooperate to control blood flow through device 800. In some embodiments, valved segment 850 may be used to replace a diseased aortic valve or other heart valve.

[0146] The apparatus 830 includes a frame 831 including a first portion 832 associated with the valved segment 850 and a second portion 833 associated with the compliance-enhancing segment 830, one or both of the frame portions 832, 833 being balloon-expandable and / or self-expanding. In some implementations, the implant device 800 may be placed in the ascending aorta with the prosthetic valve 851 of the valved segment 850 aligned with the native aortic valve. However, it should be understood that the implant device 800 may be placed / implanted anywhere within the patient's vasculature, such as within the descending aorta, thoracic aorta, inferior vena cava, superior vena cava, or other vessel. As implanted and maintained within the target vessel, the device 800 may improve arterial blood flow and / or prevent elevated blood pressure. The implant device 800 may be delivered using a minimally invasive approach, such as using a catheter. Delivery and / or implantation of the device 800 may be guided by monitoring one or more radiopaque markers on the implant device 800.

[0147] The implant device 800 can provide multiple benefits and / or solutions to the patient. For example, the device 800 can not only provide a replacement for a diseased native valve but also introduce a vascular compliance enhancement mechanism into the blood circulation. The device 800 can provide a low-profile, collapsible / self-expanding structure that can be delivered in a radially compressed / folded state within a catheter / sheath, as described above. The frame 831 can comprise any suitable or desirable material or form, as described in detail herein in connection with any of the embodiments of the present disclosure, such as stainless steel, cobalt-chromium alloy, or nickel-titanium alloy (e.g., nitinol). The use of a shape-memory material for the frame 831, as with other embodiments disclosed herein, can enable the device 800 to self-expand.

[0148] Compliance-enhancing segment 830 may comprise an inner, radially expanding tube 841, which may or may not have a compressible gas-filled chamber disposed therearound. Prosthetic valve segment 850 may comprise leaflets 855 configured to control flow through device 800, such as in a one-way valve configuration. Tube 841 and leaflets 855 may comprise any suitable or desired material, such as biological tissue or a polymeric material, and tube 841 and leaflets 855 may comprise a common material or different materials. Accordingly, compliance-enhancing segment 830 of device 800 may be understood to be similar to or identical to device 30 of FIGS. 6A-6E , device 130 of FIGS. 8A-8E , device 730 of FIGS. 13-1 and 13-2 , or any other exemplary device described herein, such device forming an axial segment / portion of device 800.

[0149] Compliance-enhancing segment 830 may be configured in any shape, form, structure, and / or function of the compliance-enhancing devices disclosed herein. For example, a compliance-enhancing device of any of the embodiments disclosed herein may be implemented as part of device 800, with the frame of the compliance-enhancing device being coupled to or integral with frame portion 832 in an axial / in-line arrangement.

[0150] Device 830 includes a frame portion 835 that joins compliance-enhancing segment 830 with valved segment 832. Frame portion 835 may be considered the neck portion of frame 831, and is spaced apart from the diameter D of compliance-enhancing segment 833 and valved segment 832. o , D f diameter D smaller than either or both of n 17A , with radially bulging segments 832, 833 separated by a narrower axial neck segment 835. In some embodiments, the length of device 800 may be 40-60 mm. For example, compliance-enhancing segment 830 may have a length of approximately 20-40 mm, e.g., approximately 30 mm, while valved segment 850 may have a length of 10-30 mm, e.g., approximately 20 mm. Furthermore, neck portion 835 may have a length of 0-10 mm, and the combined length of the various segments of the frame / device may be approximately 50 mm, or some other value between 40-60 mm.

[0151] 17A-17C show an embodiment of device 800 in which flow control / valve section 850 is located on inlet side / end 833i of device 800 while compliance enhancing section 830 is located on outlet side / end 833o of device 800, it should be understood that in certain embodiments, flow control section 850 may be located adjacent outlet side / end 833o and compliance enhancing section 830 may be located adjacent inlet side / end 833i.

[0152] FIG. 18 illustrates the compliance-enhancing implant device 800 of FIGS. 17A-17C including a valve portion 850 according to one or more embodiments.

[0153] 18-1, 18-2, and 18-3 illustrate respective designs of exemplary implementations of the valved portion 850 of the compliance implant device 800 according to one or more embodiments. The valved portion 850 is shown as including valve leaflets 851. However, it should be appreciated that the portion 850 may include any other type of flow control mechanism that may be utilized within the frame segment 832 to achieve a desired direction and / or flow rate through the apparatus 800 according to aspects of the present disclosure. In FIGS. 18-1 through 18-3, the compliance-enhancing implant device 800 is shown as including one or more one-way valves 851. These valves may be configured and / or oriented to restrict or block backflow while allowing flow in a desired flow direction f through the channel 849 of the device 800.

[0154] The valve function 855 associated with a compliance-enhancing implant device according to an embodiment of the present disclosure functions by opening to allow flow when there is a pressure gradient in the direction of the valve, causing the valve to open to allow flow and close with each cardiac cycle to prevent backflow.

[0155] As described above, the frame 831, including the valved segment 832, can be designed to be radially crimped or compressed to facilitate endovascular delivery to a target implant site. For example, the valved portion 850 can be positioned in a native valve annulus (e.g., the aortic annulus), and the frame 831 can be expanded to an operative state, e.g., by an expansion balloon, so that the leaflet structure 851 or other flow control mechanism of the valved portion 850 regulates blood flow through the native valve annulus. The frame 831 can be made of nitinol or another self-expanding material. In some implementations, the valved segment 832 of the frame 831 can be plastically expandable to its functional size by a balloon or another expansion device, in which case the frame can be made of a plastically expandable material, such as stainless steel or a cobalt-chromium alloy. Other suitable materials can also be used.

[0156] In some implementations, device 800 may mechanically expand or radially self-expand under its own resilience from a compressed delivery state to an operating state when released from a delivery sheath. The following description of valve portion / segment 850 of device 800 may be understood with reference to any of the embodiments in FIGS. 18-1 through 18-3. The exemplary implementation of valved portion 850 of device 800 shown in FIGS. 18-1, 18-2, and / or 18-3 may be similar in one or more respects to the Edwards Lifesciences SAPIEN XT™, SAPIEN 3™, and / or SAPIEN 3 Ultra™ transcatheter prosthetic heart valves.

[0157] Valved portion 850 may include an inflow end 822 and an outflow end 823, which may connect to a neck portion 835 of device 800. Valved portion 850 includes a segment 832 of a frame 831 of device 800. Valved portion 850 may further include a leaflet structure 855 supported inside frame segment 832. In some implementations, frame segment 832 is at least partially covered, on its interior and / or exterior, by a sealing skirt 813, which may comprise any suitable or desirable material, such as textured polyethylene terephthalate (PET). Skirt 813 may be attached to an inner surface of frame 832 to form a suitable / desired mounting surface for leaflets 855 of valve 851.

[0158] The frame segment 832 may include an annular structure having a plurality of vertically extending commissure attachment posts 811 that serve to attach and form the leaflet structure 855 therein. Additional vertical struts or strut members 812, along with circumferentially extending strut members 815, serve to form the remainder of the frame 832. In some embodiments, the struts 815 and / or 812 may form axial rows of cells 816 that may be circumferentially offset within the valve segment 832 (and / or the remainder of the frame 831), as in the embodiment of FIGS. 18-1 and 18-2, or the rows of cells 816 may be generally circumferentially aligned, as in the embodiment of FIG. 18-3. The open-cell shape of the frame 831 can facilitate coronary access. With further reference to the embodiment of FIG. 18-3, the strut members 815 of the frame 832 may form a chevron / zigzag shape / cells at the base portion of the frame segment 832. The struts 815 may form edged crown portions 819 or apexes at the inflow and / or outflow ends of the valved segment 832 of the frame 831 .

[0159] The skirt 813 may be attached to the frame segments 832 in any suitable or desirable manner, such as through the use of adhesive or other attachment means. In some embodiments, the skirt 813 is attached to the inner and / or outer surface of the valve frame 832 via one or more sutures 821, which may be wrapped around various struts of the frame segments 832 as needed. The skirt 813 may provide a relatively more substantial attachment surface for the portion of the leaflet structure 855 positioned near the inflow end 822 of the device 800. In some embodiments, as shown in FIGS. 18-1 and 18-2 , the skirt 813 may be folded over the inflow end of the frame 832 to cover the outer diameter / surface of the frame on the inflow end 833i of the device, and a portion of the skirt 813 on the outside of the frame 832 may facilitate attachment to the patient's anatomy, such as through tissue ingrowth and / or a friction fit between the frame 832 and the anatomy (e.g., aortic annulus, aorta, etc.). Valve 855 may include any suitable or desirable number of leaflets, such as three as shown in the illustrated embodiment.

[0160] 19 illustrates the aortic anatomy with a valved compliance implant device deployed at an exemplary location in the anatomy, according to one or more embodiments. The hourglass shape of device 800 and / or frame 831 can facilitate secure lodging / anchoring within the target anatomy, which may be, for example, the ascending portion of the aorta or other vascular segment. For example, narrower neck portion 835 can allow frame 831 to flex / curve to some extent to conform to the target anatomy (e.g., the aorta). Furthermore, wider valved segment 832 can be sized to fit within the relatively wider space of the ascending aorta, such as the area immediately adjacent to or within the aortic valve annulus and / or within the area where coronary arteries 191 originate from the aorta. In some implementations, valved portion 850 is configured to be positioned and anchored within the native aortic valve annulus, and the expanded diameter of frame segment 832 can accommodate such positioning.

[0161] The frame 831 may be self-expanding and / or balloon-assisted, with a resilient compliance-enhancing member and a prosthetic heart valve, and the device 800 is configured to be placed within the ascending aorta 12 with the prosthetic valve aligned with the diseased native aortic valve 7. While shown implanted within and / or near the aortic valve 7, it should be understood that the device 800 may be placed anywhere within the patient's vasculature. The implant device 800 may serve to improve arterial blood flow and / or prevent elevated blood pressure. The frame 831 may be a one-piece frame having an hourglass shape, as shown. That is, the frame segments 832, 833 may be integrated into a common frame / form, with a neck portion 835 separating the frame segments 832, 833. While shown in some embodiments as bulging axially outward, it should be understood that the frame segments of the device 800 may not bulge but may rather be straight, as shown in the examples of FIGS. 18-1, 18-2, and 18-3. That is, the diameter of valve segment 832 and / or compliance segment 833 may be continuous over at least a portion of its length.

[0162] The device 800 can be delivered to the target anatomy using a minimally invasive approach, such as using a process involving a catheter guided by a radiopaque marker associated with the implant 800. In some implementations, the device 800 can be minimally invasively implanted into the apical region of the ventricle of the heart and transapically through the ventricle into the target aortic anatomy. In some implementations, the native aortic valve 7 remains intact, and the valved portion 850 of the device 800 provides an additional valve in the ascending and descending portions of the aorta 16. In some implementations, the device 800 can be implanted on both sides of the renal arteries, and the valved portion 850 can function to prevent backflow and / or aid in perfusion of the kidney. For example, the device 800 can function to increase pressure in the arterial side of the renal circulation, thereby improving perfusion. sterile

[0163] Any of the various systems, devices, equipment, etc. in the present disclosure may be sterilized (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure they are safe for use on patients, and the methods described herein may include sterilization of the associated systems, devices, equipment, etc. (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.).

[0164] Further description of the embodiment Below is provided a list of examples, each of which may include aspects of any of the other examples disclosed herein. Furthermore, aspects of any of the examples described above may be implemented in any of the numbered examples provided below.

[0165] Example 1: An implant device comprising a frame having an axially expanding cylindrical shape in an expanded configuration of said frame, and a radially expandable tube disposed within said frame.

[0166] Example 2: An implant device as described in any example herein, particularly example 1, wherein the mid-diameter of the frame is at least 20% greater than the end diameter of the frame at at least one axial end of the frame.

[0167] Example 3: An implant device as described in any example herein, particularly Example 2, wherein the frame expands from the end diameter to the mid-diameter in the outer quadrants of the frame's length such that the frame has the mid-diameter over at least half of the frame's length.

[0168] Example 4: An implant device as described in any example herein, particularly example 2 or example 3, wherein the diameter of the frame gradually expands from the end diameter to the inner diameter to form a convex cylindrical shape.

[0169] Example 5: An implant device as described in any example herein, particularly any of Examples 1-4, wherein the tube has a diameter in its relaxed configuration that is at least 20% less than the mid-diameter of the frame.

[0170] Example 6: An implant device as described in any example herein, especially Example 5, wherein the diameter of the tube is within 10% of the end diameter of the frame.

[0171] Example 7: An implant device as described in any example herein, particularly any of Examples 1-6, wherein the tube is connected to a frame at the first and second axial ends of the implant device.

[0172] Example 8: An implant device as described in any example herein, particularly Example 7, wherein one or more openings are present at a first axial end of the implant device, and the one or more openings provide one or more flow paths within the space between the outer diameter of the tube and the inner diameter of the frame.

[0173] Example 9: An implant device as described in any example herein, particularly Example 8, wherein the one or more openings comprise one or more gaps between the tube and the frame at the first axial end of the implant device.

[0174] Example 10: An implant device as described in any example herein, particularly Example 9, wherein the axial end of the tube is joined to the axial end of the frame using sutures, and the one or more openings are formed by one or more gaps in the sutures.

[0175] Example 11: An implant device as described in any example herein, particularly Example 10, wherein the axial end of the tube is deflected radially inward in at least one of the one or more gaps in the suture to form one or more inlet channels in the space between the outer diameter of the tube and the inner diameter of the frame.

[0176] Example 12: An implant device as described in any example herein, particularly any of Examples 1-11, further comprising one or more fluid-filled chambers disposed between the radially expandable tube and the frame.

[0177] Example 13: An implant device as described in any example herein, especially Example 12, wherein one or more fluid-filled chambers have a compressible gas contained therein.

[0178] Example 14: An implant device as described in any example herein, especially Example 13, wherein one or more fluid-filled chambers have foam disposed therein.

[0179] Example 15: The implant device of any example herein, particularly any of Examples 1-14, wherein the tube is joined at its first and second axial ends to the respective first and second axial ends of the frame by at least one of heat sealing, mechanical crimping, or suturing.

[0180] Example 16: An implant device as described in any example herein, particularly any of Examples 1-15, wherein the tube is sutured to a suture ring associated with the axial end of the frame.

[0181] Example 17: An implant device as described in any example herein, particularly any of Examples 1-16, wherein a radially expandable tube is disposed within a first axial portion of the frame, an axially expanding cylindrical form is associated with the first axial portion, and the frame includes a second axial portion having a valve associated therewith.

[0182] Example 18: The implant device of any example herein, particularly example 17, wherein the frame further comprises a neck portion disposed between the first axial portion and the second axial portion.

[0183] Example 19: An implant device as described in any example herein, particularly Example 18, wherein the neck portion of the frame has a diameter smaller than both the maximum diameter of the first axial portion and the maximum diameter of the second axial portion, forming an hourglass shape of the frame.

[0184] Example 20: An implant device as described in any example herein, particularly example 19, wherein the second axial portion has a sealing skirt sutured thereto.

[0185] Example 21: An implant device as described in any example herein, particularly example 20, wherein the sealing skirt is wrapped around the axial end of the frame such that the sealing skirt is positioned on both the outer and inner surfaces of the second axial portion of the frame.

[0186] Example 22: An implant device as described in any example herein, particularly example 17, wherein the valve comprises a plurality of leaflets connected to the frame at a second axial portion of the frame.

[0187] Example 23: An implant device as described in any example herein, particularly Example 17, further comprising one or more gas-filled chambers disposed between the radially expandable tube and the frame in the first axial portion of the frame.

[0188] Example 24: An implant device as described in any example herein, particularly example 17, wherein the first axial portion is downstream of the second axial portion relative to a flow direction associated with the valve.

[0189] Example 25: An implant device comprising: a frame having an axially convex configuration with a diameter expanding from first and second axial ends of the frame moving to an inner portion of the frame; and a cylindrical toroidal balloon member at least partially disposed within the frame, the balloon member defining a central axial flow path.

[0190] Example 26: An implant device as described in any example herein, especially example 25, wherein the balloon member comprises one or more gas-filled chambers.

[0191] Example 27: An implant device as described in any example herein, particularly Example 26, wherein one or more gas-filled chambers are formed between an outer layer of the balloon member and an inner layer of the balloon member that forms a central axial channel.

[0192] Example 28: An implant device as described in any example herein, particularly any of Examples 26 or 27, wherein one or more gas-filled chambers occupy a space between the flow channel and the frame.

[0193] Example 29: An implant device described in any example herein, particularly any of Examples 26-28, wherein one or more gas-filled chambers are configured to radially compress when the pressure in the flow path is greater than the pressure of the gas in the one or more gas-filled chambers.

[0194] Example 30: An implant device as described in any example herein, particularly Example 29, wherein the frame comprises radially outwardly protruding tissue anchors configured to embed into the wall of the blood vessel when the frame is expanded within the blood vessel.

[0195] Example 31: An implant device described in any example herein, particularly any of Examples 26-30, wherein the mid-diameter of the frame is at least 20% larger than the end diameter of the frame at at least one axial end of the frame.

[0196] Example 32: An implant device as described in any example herein, especially example 31, wherein the diameter of the frame gradually expands from the end diameter to the inner diameter to form a convex cylindrical shape.

[0197] Example 33: An implant device described in any example herein, particularly any of Examples 26-32, wherein the flow path has a diameter that is at least 20% smaller than the mid-diameter of the frame when the balloon member is in an uncompressed configuration.

[0198] Example 34: An implant device as described in any example herein, especially example 33, wherein the diameter of the flow channel is within 10% of the end diameter of the frame when the balloon member is in an uncompressed configuration.

[0199] Example 35: An implant device comprising a tubular frame having a first axial segment and a second axial segment, a radially expandable tube disposed within the first axial segment of the frame, and a one-way valve disposed within the second axial segment of the frame.

[0200] Example 36: An implant device as described in any example herein, particularly example 35, wherein the first axial segment has a first maximum diameter, the second axial segment has a second maximum diameter, and a third axial segment of the frame disposed between the first axial segments has a third maximum diameter that is smaller than the first maximum diameter and the second maximum diameter.

[0201] Example 37: An implant device described in any example herein, particularly any of Examples 35 or 36, wherein the first axial segment has an axial bulge configuration in which the diameter increases from a first diameter at an axial end of the first axial segment to a second diameter at an inner axial portion of the first axial segment that is at least 20% larger than the first diameter.

[0202] Example 38: An implant device as described in any example herein, particularly Example 37, wherein when the radially expandable tube is in an unexpanded configuration, a space exists between the outer diameter of the tube and the inner diameter of the frame, the space providing a volume within which the tube can radially expand.

[0203] Example 39: An implant device described in any example herein, particularly Example 38, wherein the tube is coupled to the first axial segment in a manner that provides fluid access to the space between the outer diameter of the tube and the inner diameter of the frame.

[0204] Example 40: An implant device described in any example herein, particularly any of Examples 38 or 39, wherein the tube comprises one or more holes providing fluid access to the space between the outer diameter of the tube and the inner diameter of the frame.

[0205] Example 41: A method of controlling blood flow in a blood vessel, the method comprising providing a delivery system having an implant device disposed therein, the implant device comprising a tubular frame in a radially crimped configuration and a radially expandable tube disposed within the frame. The method further comprises advancing a distal portion of the delivery system to a target location within a portion of the patient's aorta, deploying the implant device from the distal portion of the delivery system, and radially expanding the frame into an axially expanded cylindrical shape having an inner diameter at least 20% larger than the diameter of the portion of the aorta prior to expansion.

[0206] Example 42: The method of any example herein, particularly Example 41, further comprising withdrawing the delivery system from the aorta when the tube is in an unexpanded configuration, and receiving blood flow into a flow channel formed in the tube, wherein the blood flow causes the tube to radially expand into a volume between the flow channel of the frame and the axially expanding cylindrical form.

[0207] Example 43: The method of any example herein, especially Example 42, wherein the tube radially expands, followed by radial contraction of the tube, thereby pushing blood through the implant device.

[0208] Example 44: The method of any example herein, especially Example 43, wherein said radial contraction of the tube draws blood into the volume within the space between the outer surface of the tube and the inner surface of the frame.

[0209] Example 45: A method as described in any example herein, particularly Example 44, wherein after said drawing of blood into the space between the outer surface of the tube and the inner surface of the frame, the fluid pressure in the flow path is greater than the fluid pressure in the space.

[0210] Example 46: The method of any example herein, particularly any of Examples 44 or 45, wherein the tube is connected to a frame at the first and second axial ends of the implant device.

[0211] Example 47: The method of any example herein, particularly Example 46, wherein one or more openings are present at the first axial end of the implant device, and wherein said drawing of blood into the space between the outer surface of the tube and the inner surface of the frame is through one or more openings.

[0212] Example 48: The method of any example herein, particularly any of Examples 41-47, wherein the inner diameter is at least 30% greater than the diameter of the portion of the aorta.

[0213] Example 49: The method of any example herein, particularly any of Examples 41-48, wherein the inner diameter is at least 40% greater than the diameter of the portion of the aorta.

[0214] Example 50: The method of any example herein, particularly any of Examples 41-49, wherein the axially expanding cylindrical shape has a diameter that gradually expands from its ends to an intermediate diameter at the axial center of the frame.

[0215] Example 51: The method described in any example herein, particularly any of Examples 41-50, wherein after radially expanding the frame, the end diameter of the frame is within 10% of the diameter of a portion of the aorta.

[0216] Depending on the embodiment, certain acts, events, or functions of any of the processes or algorithms described herein may be performed in a different order, added, combined, or omitted entirely. Thus, in a particular embodiment, not all described acts or events may be required to practice a process.

[0217] In particular, conditional language used herein, such as "can," "could," "might," "may," "e.g.," and the like, is intended to have its ordinary meaning unless specifically stated otherwise or understood otherwise within the context of use, and is generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not. Thus, such conditional language is generally not intended to imply that the features, elements, and / or steps are in any way required for one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without authorial input or prompting, whether those features, elements, and / or steps are included in or should be performed in any particular embodiment. Terms such as "comprising," "including," "having," and the like are synonymous and used in their ordinary sense, and are used in an inclusive, non-limiting manner and do not exclude additional elements, features, acts, operations, etc. Additionally, the term "or" is used in its inclusive sense (and not its exclusive sense), for example, when used to connect a list of elements, so that the term "or" refers to one, some, or all of the elements in the list. Connective language such as the phrase "at least one of X, Y, and Z" is understood in context as being used generally to convey that an item, term, element, etc., can be either X, Y, or Z, unless specifically stated otherwise. Thus, such connective language is not generally intended to imply that a particular embodiment requires that at least one of X, at least one of Y, and at least one of Z, each be present.

[0218] In the foregoing description of embodiments, it should be understood that various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, this method of disclosure should not be interpreted as reflecting an intention that any claim requires more features than are expressly recited in that claim. Moreover, any component, function, or step illustrated and / or described in a particular example herein may be applied to or used in conjunction with any other embodiment. Moreover, no component, function, step, or group of components, functions, or steps is necessary or essential to each embodiment. Accordingly, it is intended that the scope of the invention(s) herein, as disclosed and claimed below, should not be limited by the specific embodiments described above, but should be determined solely by a fair reading of the following claims.

[0219] It should be understood that certain sequential terms (e.g., "first" or "second") may be provided for ease of reference and do not necessarily imply a physical function or order. Thus, as used herein, sequential terms (e.g., "first," "second," "third," etc.) used to modify elements such as structures, components, operations, etc., do not necessarily indicate a priority or order of the element relative to any other elements, but rather may generally distinguish an element from other elements having a similar or identical name (except for the use of sequential terms). Additionally, as used herein, the indefinite articles ("a" and "an") may indicate "one or more" rather than "one." Furthermore, an operation performed "based on" a condition or event may also be performed based on one or more other conditions or events not explicitly recited.

[0220] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the illustrative examples belong. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and are not to be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0221] Spatially relative terms such as "outside," "inside," "upper," "lower," "bottom," "upper," "vertical," "horizontal," and similar terms may be used herein for ease of description to describe the relationship between one element or component and another element or component, as shown in the figures. It is understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device shown in the figures is turned upside down, a device positioned "below" or "directly below" another device may be positioned "above" another device. Thus, the exemplary term "below" can include both a lower position and an upper position. Devices may also be oriented in other directions, and thus spatially relative terms may have different interpretations depending on the orientation.

[0222] Unless expressly stated otherwise, comparative and / or quantitative terms such as "less," "more," "greater than," and the like are intended to encompass equivalent concepts. For example, "less" can mean "less than" as well as "less than" in the strictest mathematical sense.

Claims

1. It is an implantable device, The extended configuration of the frame includes a frame having a cylindrical shape that bulges in the axial direction, An implantable device comprising a radially expandable tube arranged within the frame.

2. The intermediate diameter of the frame is at least 20% larger than the end diameter of the frame at at least one axial end of the frame. The frame extends from the end diameter of the outer quarter of the frame's length to the intermediate diameter, such that the frame has the intermediate diameter over at least half of the frame's length, or The implant device according to claim 1, wherein the diameter of the frame gradually expands from the end diameter to the intermediate diameter to form a convex cylindrical shape.

3. The implant device according to claim 1, wherein the tube has a diameter at least 20% smaller than the inner diameter of the frame in its relaxation configuration.

4. The implant device according to claim 1, wherein one or more openings are present at the first axial end of the implant device, and the one or more openings provide one or more flow paths in the space between the outer diameter of the tube and the inner diameter of the frame.

5. The axial end of the tube is joined to the axial end of the frame by suture, The implant device according to claim 1, wherein the one or more openings are formed by one or more gaps in the suture.

6. The implant device according to claim 5, wherein the axial end of the tube is deflected radially inward in at least one of the one or more gaps in the suture, forming one or more inlet channels in the space between the outer diameter of the tube and the inner diameter of the frame.

7. The implant device according to claim 1, wherein one or more fluid-filled chambers have a foam disposed therein.

8. The implant device according to claim 1, wherein the tube is either a) joined at its first and second axial ends to the respective first and second axial ends of the frame by at least one of heat sealing, mechanical crimping, or suturing, or b) sutured to a suture ring associated with the axial end of the frame.

9. The radially expandable tube is positioned within the first axial portion of the frame, and the axially expanding cylindrical shape is associated with the first axial portion. The implant device according to claim 1, wherein the frame includes a second axial portion having a one-way valve associated therewith.

10. The implant device according to claim 9, wherein the frame further includes a neck portion disposed between the first axial portion and the second axial portion, the neck portion of the frame having a diameter smaller than both the maximum diameter of the first axial portion and the maximum diameter of the second axial portion, and forming an hourglass shape of the frame.

11. The implant device according to claim 10, wherein the second axial portion has a sealing skirt sutured thereto.

12. The implant device according to claim 9, wherein the one or more fluid-filled chambers further comprises one or more gas-filled chambers disposed between the radially expandable tube and the frame in the first axial portion of the frame.

13. It is an implantable device, A frame having an axially convex shape in which the diameter increases as it moves from the first and second axial ends of the frame to the inner portion of the frame, An implantable device comprising a cylindrical toroidal balloon member having one or more gas-filled chambers at least partially disposed within the frame, wherein the balloon member forms a central axial flow path.

14. The one or more gas-filled chambers a) A layer formed between the outer layer of the balloon member and the inner layer of the balloon member that forms the central axial channel, and / or b) The implant device according to claim 13, which occupies the space between the flow channel and the frame.

15. The implant device according to claim 13, wherein one or more gas-filled chambers are configured to compress radially when the pressure in the flow path is greater than the pressure of the gas in the one or more gas-filled chambers.

16. It is an implantable device, A tubular frame comprising a first axial segment and a second axial segment, A radially expandable tube disposed within the first axial segment of the frame, An implantable device comprising a one-way valve disposed within the second axial segment of the frame.

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