Removal of fluid trapped in the stent

Abstract

The stent implant includes a first stent segment having a non-circular axial cross-sectional shape in a relaxed configuration; second and third stent segments on either side of the first stent segment, the second and third segments having a circular relaxed axial cross-sectional shape; a liquid-tight cover positioned on at least one of the outer or inner diameters of the first, second, and third stent segments; and a blood flow outlet channel fluid-communicating with a space on the outer diameter of the first stent segment, configured to allow blood to pass through the blood flow outlet channel and exit the space axially.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority to U.S. Provisional Patent Application No. 63 / 489,850, filed on 13 March 2023 and titled “STENT TRAPPED FLUID REMOVAL,” the complete disclosure of which is incorporated herein by reference in its entirety. [Background technology]

[0002] This disclosure relates, in general, to the field of medical implant devices, including stent implant devices. Stent implant devices may be designed for intravascular deployment. Blood stagnation between the stent implant device and vascular tissue, such as the gap formed between the stent frame and the vessel wall, can affect patient outcomes. [Overview of the project] [Means for solving the problem]

[0003] Devices, methods, and systems relating to non-circular stent devices / assemblies, including blood drainage and / or suction components / elements, are described herein. Such components / elements can facilitate the fitting configuration of the stent implant device, the non-circular segment, around the stent wall, and the vascular wall, when otherwise captured blood is drained from the space / region between the stent wall and the vascular wall. Blood drainage and / or suction components / elements relating to this disclosure may include blood flow tubes, valves, and / or combinations thereof. An expansion device, such as a tubular balloon, can be used to expand the non-circular stent segment to induce blood drainage, which in some embodiments may pass through tubes and / or valve components. For stent implant devices including a liquid-tight cover, the blood drainage / suction features disclosed herein may reduce the risk of blood stasis radially outward from the stent.

[0004] For the purpose of summarizing this disclosure, specific aspects, advantages, and novel features are described. It will be understood that not all such advantages can necessarily be achieved according to any particular example. Accordingly, the disclosed examples may be implemented in a manner that achieves or optimizes one or a group of advantages as taught herein, without necessarily achieving other advantages that may be taught or suggested herein.

[0005] Any embodiment of the methods and structures disclosed herein for treating a patient also includes similar methods and structures performed on or placed on a simulated patient, which are useful, for example, training, demonstration, treatment and / or device development, and the like. The simulated patient may be physical, virtual, or a combination of physical and virtual. The simulation may include a simulation of all or part of a patient, e.g., the whole body, a part of the body (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, synthetic, or any combination of natural and synthetic, including human or animal carcasses or parts thereof. The virtual elements may be entirely in silica or may be overlaid on one or more of the physical components. The virtual elements may be presented on any combination of screens, headsets, holographics, projections, loudspeakers, headphones, pressure transducers, and temperature transducers, or using any combination of suitable technologies.

[0006] Any of the various systems, devices, apparatus, etc. of this disclosure can be sterilized (e.g., by heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure that they are safe for use in patients, and the methods herein may include sterilization (e.g., by heat, radiation, ethylene oxide, hydrogen peroxide, etc.) of the relevant systems, devices, apparatus, etc.

[0007] Various embodiments are shown in the accompanying drawings for illustrative purposes and should in no way be construed as limiting the scope of the present invention. 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 numbers may be reused to indicate corresponding between reference elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] [Figure 1] FIG. 1 shows an example of the anatomical structure of the heart and blood vessels. [Figure 2A] FIGS. 2A and 2B each show a side view and an axial cross-sectional view of a compliant blood vessel that experiences compliant expansion and contraction during the cardiac cycle. [Figure 2B] FIGS. 2A and 2B each show a side view and an axial cross-sectional view of a compliant blood vessel that experiences compliant expansion and contraction during the cardiac cycle. [Figure 3] FIG. 3 shows an exemplary stiff aorta. [Figure 4-1] FIGS. 4-1 and 4-2 each show a blood vessel with a circular and a non-circular axial cross-sectional shape, respectively. [Figure 4-2] FIGS. 4-1 and 4-2 each show a blood vessel with a circular and a non-circular axial cross-sectional shape, respectively. [Figure 5A] FIGS. 5A and 5B each show a perspective view and an axial view of a non-circular stent disposed within a blood vessel. [Figure 5B] FIGS. 5A and 5B each show a perspective view and an axial view of a non-circular stent disposed within a blood vessel. [Figure 6A] FIGS. 6A and 6B each show a perspective view and an axial view of a non-circular stent disposed within a blood vessel according to one or more embodiments. [Figure 6B] FIGS. 6A and 6B each show a perspective view and an axial view of a non-circular stent disposed within a blood vessel according to one or more embodiments. [Figure 7A]Figures 7A to 7D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 7B] Figures 7A to 7D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 7C] Figures 7A to 7D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 7D] Figures 7A to 7D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 8A] Figures 8A to 8D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 8B] Figures 8A to 8D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 8C] Figures 8A to 8D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 8D] Figures 8A to 8D show perspective, side, and axial views of stents having a circular end portion and a non-circular inner portion, respectively, according to one or more embodiments. [Figure 9A] Figures 9A and 9B show perspective and axial views, respectively, of a stent having an elliptical (non-peanut) end portion and a peanut-shaped inner portion, according to one or more embodiments. [Figure 9B] Figures 9A and 9B show perspective and axial views, respectively, of a stent having an elliptical (non-peanut) end portion and a peanut-shaped inner portion, according to one or more embodiments. [Figure 10A]Figures 10A and 10B show a side view and an axial view, respectively, of an intravascular stent implant device in which captured blood is collected around a portion(s) of the stent implant, according to one or more embodiments. [Figure 10B] Figures 10A and 10B show a side view and an axial view, respectively, of an intravascular stent implant device in which captured blood is collected around a portion(s) of the stent implant, according to one or more embodiments. [Figure 11A] Figures 11A and 11B show a side view and an axial view, respectively, of a stent implant device including one or more fluid suction / discharge pipes. [Figure 11B] Figures 11A and 11B show a side view and an axial view, respectively, of a stent implant device including one or more fluid suction / discharge pipes. [Figure 12A] Figures 12A and 12B show side and axial views, respectively, of a stent implant device having blood passing through its associated fluid suction / discharge tube(s). [Figure 12B] Figures 12A and 12B show side and axial views, respectively, of a stent implant device having blood passing through its associated fluid suction / discharge tube(s). [Figure 13A] Figures 13A and 13B show a side view and an axial view, respectively, of a stent implant device having one or more fluid discharge valves. [Figure 13B] Figures 13A and 13B show a side view and an axial view, respectively, of a stent implant device having one or more fluid discharge valves. [Figure 14A] Figures 14A and 14B show side and axial views, respectively, of a stent implant device having blood passing through its associated discharge valve(s). [Figure 14B] Figures 14A and 14B show side and axial views, respectively, of a stent implant device having blood passing through its associated discharge valve(s). [Figure 15A] Figures 15A and 15B show a side view and an axial view, respectively, of a stent implant device associated with a fluid discharge balloon, according to one or more embodiments. [Figure 15B] Figures 15A and 15B show a side view and an axial view, respectively, of a stent implant device associated with a fluid discharge balloon, according to one or more embodiments. [Figure 16A] Figures 16A and 16B show a side view and an axial view, respectively, of a stent implant device having an expanded fluid discharge balloon therein, according to one or more embodiments. [Figure 16B] Figures 16A and 16B show a side view and an axial view, respectively, of a stent implant device having an expanded fluid discharge balloon therein, according to one or more embodiments. [Modes for carrying out 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] While certain preferred examples are disclosed below, it should be understood that the subject matter of the invention extends beyond the specifically disclosed examples to other alternative examples and / or uses, as well as their modifications and equivalents. Therefore, the claims that may arise from this specification are not limited by any of the specific examples described below. For example, in any method or process disclosed herein, the action or operation of the method or process may be performed in any preferred order, and is not necessarily limited to any specific disclosed order. Various operations may be described sequentially as a number of separate operations in a manner that may be useful for understanding a particular embodiment; however, the order of description should not be interpreted as implying that these operations are order-dependent. Furthermore, the structures, systems, and / or devices described herein may be embodied as integrated components or as separate components. For the purpose of comparing various embodiments, specific aspects and advantages of these embodiments are described. Not all such aspects or advantages are necessarily achieved by any particular embodiment. Therefore, for example, various examples may be implemented in a manner that achieves or optimizes one or a set of advantages as taught herein, without necessarily achieving other embodiments or advantages that may similarly be taught or suggested herein.

[0011] Certain reference numerals are reused across different drawings in the entire disclosure for convenience of relating to devices, components, systems, features, and / or modules that may have similar functions in one or more respects. However, in any example disclosed herein, the reuse of common reference numerals in a drawing does not necessarily indicate that such features, devices, components, or modules are identical or similar. Rather, a person skilled in the art can infer from the context the degree to which the use of common reference numerals may suggest similarity between the referenced subjects. The use of a particular reference numeral in the context of a description of a particular drawing can be understood as relating to a device, component, aspect, function, module, or system identified in that particular drawing, and not necessarily relating to any device, component, aspect, feature, module, or system identified by the same reference numeral in another drawing. Furthermore, aspects relating to separate drawings identified by a common reference numeral can be interpreted as sharing characteristics or as being completely independent of each other.

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

[0013] Specific standard anatomical terms for location are used herein to refer to animal, i.e., human, anatomical structures in relation to various embodiments. Certain spatially relative terms, such as “lateral,” “medial,” “super,” “super,” “below,” “down,” “up,” “vertical,” “horizontal,” “apex,” and “base,” 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, but these terms are used herein for ease of explanation to describe the positional relationships between elements / structures as shown in the drawings. 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 illustrated in the drawings. For example, an element / structure described as “above” another element / structure may represent a position below or to the side of such other element / structure with respect to the patient or alternative orientation of the element / structure in question, and vice versa. It should be understood that spatially relative terms, including those listed above, can be understood in relation to each illustrated orientation of the referenced figure.

[0014] Vascular anatomical structure and compliance In the context of vascular implant devices, particularly implant devices having a non-circular segment with associated tissue engagement elements, certain examples are disclosed herein, such implant devices being implanted in the aorta. However, while certain principles disclosed herein may be particularly applicable to the anatomical structure of the aorta, it should be understood that stent implant devices having tissue engagement elements according to this disclosure may be implanted in or configured for implantation in any suitable or desirable blood vessel or other anatomical structure, such as the inferior vena cava.

[0015] The anatomical structure of the heart and the vascular system are described below to aid in understanding the concepts of the particular inventions disclosed herein. In humans and other vertebrates, the heart generally comprises a muscular organ having four pump chambers, the flow of which is at least partially controlled by various heart valves, namely the aortic valve, the mitral valve (or bicuspid valve), the tricuspid valve, and the pulmonary valve.

[0016] Figure 1 shows an exemplary representation of a heart 1 and associated vascular system having various functions relating to one or more embodiments of the disclosure of the present invention. The heart 1 comprises four chambers, namely the left atrium 2, the left ventricle 3, the right ventricle 4, and the right atrium 5. In terms of blood flow, blood generally flows from the right ventricle 4 through the 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 so that blood can be pumped toward the lungs and close during diastole to prevent backflow of blood from the pulmonary artery 11 into the heart. The pulmonary artery 11 carries deoxygenated blood from the right side of the heart to the lungs. As shown, the pulmonary artery 11 comprises the pulmonary trunk and the left and right pulmonary arteries branching 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 coronary leaflets and generally closes during ventricular contraction (i.e., systole) and opens during ventricular diastole (i.e., diastole). The mitral valve 6 generally has two coronary 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, is configured 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. The muscular wall 17, called the septum, separates the left 2 and right 5 atria, as well as the left 3 and right 4 ventricles.

[0018] A heart valve may generally consist of a relatively dense fibrous ring, referred to herein as the annulus, and several leaflets, or cusps, attached to the annulus. Generally, the size of the leaflets, or coronary cusps, may be such that when the heart contracts, the increase in blood pressure occurring within the corresponding chamber causes the leaflets to open at least partially, thereby allowing flow from the chamber. When the pressure within the chamber decreases, the pressure in the subsequent chamber or blood vessel may become dominant and push back the leaflets. As a result, the leaflets / coronary cusps juxtapose with each other, thereby closing the flow path.

[0019] The vascular structure of the human body, which can be called the circulatory system, cardiovascular system, or vascular system, includes a complex network of blood vessels with various structures and functions, and includes 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 19 and superior vena cava 18 return blood to the heart.

[0020] The aorta 16 is a compliant arterial vessel that buffers and conducts pulsatile left ventricular output and contributes to the largest component of the total compliance of the arterial tree. The aorta 16 includes the ascending aorta 12, which begins 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 to each other, causing the aorta 12 to begin on the posterior side of the pulmonary trunk 11, but twisting to its right and anterior sides to terminate. Of the various segments of the aorta 16, the ascending aorta 12 is relatively more frequently affected by aneurysms and incisions, and often requires open-heart surgery for repair. The transition from the ascending aorta 12 to the aortic arch 13 is at the pericardial reflex over the aorta. At the root of the ascending aorta 12, the lumen has three small pockets between the coronary cusps of the aortic valve and the aortic wall, which are called the aortic sinuses, or sinuses of Valsalva. The left aortic sinus contains the origin of the left coronary artery, and similarly, the right aortic sinus gives rise to the right coronary artery. Both of these arteries supply nutrients to the heart.

[0021] As described above, the aorta 16 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 further as the abdominal aorta 15. In this specification, references to the aorta will be understood to refer to the ascending aorta 12 (also called the “ascending thoracic aorta”), the aortic arch 13, the descending aorta, or the thoracic aorta 14 (also called the “descending thoracic aorta”), the abdominal aorta 15, or other arterial vessels, or parts thereof.

[0022] Arteries, such as the aorta 16, can store and release energy through stretching of the vessel wall by utilizing vascular compliance (e.g., arterial compliance). The term “compliance” is used herein in accordance with its broad and ordinary sense and refers to the ability of an arterial vessel or artificial implant device to expand, dilate, stretch, or otherwise deform, such as by increasing volume, in response to an increase in transwall pressure or a tendency of the vessel (e.g., artery) or artificial implant device or a portion thereof to resist rebound toward its original dimensions.

[0023] Figures 2A and 2B show lateral and axial sections, respectively, of a healthy aorta 16 from Figure 1, experiencing compliant dilation and systole throughout the cardiac cycle.

[0024] As described above, the systolic phase of the cardiac cycle is associated with the pumping phase of the left ventricle, while the diastolic phase of the cardiac cycle is associated with the resting or filling phase of the left ventricle. As shown in Figures 2A and 2B, with proper arterial compliance, an increase in arterial pressure from diastole to systole generally results in an increase in arterial volume Δv. As blood is pumped through the aortic valve 7 into the aorta 16, the pressure in the aorta increases, and the diameter of at least a portion of the aorta expands. The first portion of blood entering the aorta 16 in systole may pass through the aorta in systole, while the second portion (e.g., about half of the total blood volume) may be stored in an expanded volume Δv caused by compliant stretching of the vessel 16, such as from a non-expanded diameter d1 to an expanded diameter d2, thereby storing energy to contribute to perfusion during diastole. A compliant aorta can generally stretch with each heartbeat so that the diameter of at least a portion of the aorta expands.

[0025] As a result of arterial compliance, the tendency of arteries to stretch in response to pressure can have a significant effect on perfusion and / or blood pressure in some patients. For example, arteries with relatively high compliance may be tuned to deform more easily than arteries with lower compliance under the same pressure conditions. Compliance (C) may also be calculated using the following equation, where Δv is the change in vascular volume (e.g., mL) and ΔP is the pulse pressure from systole to diastole (e.g., mmHg).

[0026]

number

[0027] In elderly individuals, as well as in patients with heart failure and / or atherosclerosis, aortic and other arterial compliance may be reduced or lost to some extent. Such reduced compliance can decrease the supply of blood to the body's organs due to decreased blood flow during diastole. Among the risks associated with insufficient arterial compliance, a significant risk for such patients is reduced blood supply to the myocardium itself. For example, during systole, the contraction of the heart, which holds the heart at relatively high pressure, may 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 thus on aortic / arterial compliance.

[0028] Insufficient perfusion of the myocardium can lead to and / or be associated with heart failure. Heart failure is a clinical syndrome characterized by certain symptoms, including shortness of breath, ankle swelling, fatigue, and others. Heart failure may be accompanied by certain signs, including elevated jugular venous pressure, lung crackling, and peripheral edema, which can be caused by structural and / or functional cardiac abnormalities, for example. Such conditions can result in decreased cardiac output and / or increased intracardiac pressure, at rest or under stress.

[0029] Figure 3 shows an exemplary rigid aorta 16'. As shown in Figure 3, the aorta tends to change shape as a function of age, resulting in a greater degree of curvature or flexure over time. As the vascular structure in question loses elasticity, arterial blood pressure (e.g., left ventricular afterload) becomes more pulsatile, which can have detrimental effects, such as undesirable pulsatile arterial blood flow, including left ventricular muscle thickening and / or diastolic heart failure. Rigidity of the aorta and / or other blood vessels may result from increased collagen content and / or a corresponding decrease in elastin.

[0030] When the vascular 16' wall resists stretching due to its rigidity, the dilation of the vascular diameter from the non-dilated diameter to the dilated diameter may be limited / reduced compared to the dilation of a healthy vessel. As blood pressure increases, a stiff aorta 16' may experience some dilation and volume change, or the vessel may be stiff enough that virtually no vasodilation occurs during systole.

[0031] Embodiments of this disclosure provide a stent implant device having a non-circular frame segment and a captured blood drainage / suction element, which can be implanted / fixed to one or more locations in a damaged aorta and / or other blood vessel(s). For example, Figure 3 shows an example of the location of a stent 101 fixed to a blood vessel wall using the features / embodiments disclosed herein, such a stent can be implanted / positioned in various potential regions of the aorta 16'.

[0032] Compliance-enhanced stent implants The exemplary stent implant devices disclosed herein are configured to re-add and / or increase compliance to the aorta or other arterial (or venous) vessel(s) and / or to provide improved perfusion to the myocardium and / or other organs of the body(s). For example, the exemplary stent implant devices of this disclosure may include a stent configured, when implanted, to reduce the cross-sectional area / volume of the target vascular segment into which the stent is implanted during low-pressure conditions such as diastole, during which diastole plays a role in forcing blood through the vascular segment by pushing through the vessel as the vascular volume decreases in association with stent contraction, which is induced by a periodic drop in blood pressure.

[0033] The non-circular (e.g., elliptical, and / or peanut-shaped) stents of this disclosure may be advantageously configured to generate a differential cross-sectional area, or volume, of a target vessel (e.g., the aorta) between high-pressure and low-pressure phases of the cardiac cycle to facilitate perfusion. As described above, relatively non-compliant vessels may generally be unable to stretch and thereby lengthen their circumference in response to increasing pressure conditions. Such inability to stretch may prevent compliant dilation of the vessel.

[0034] By manipulating / reshaping the natural vessel wall, non-circular stents can be used to generate compliant (complaint) changes in vessel volume without requiring vessel grafting or resection, thereby increasing compliance in the target vessel. Thus, compared to blood flow solutions involving vessel grafting / resection, the examples of non-circular stents in this disclosure can provide a solution that avoids certain risks that may be associated with rupture and / or device rupture within / into such vessels, which may present a risk of rupture and blood leakage outside the circulatory system.

[0035] With respect to vessels with relatively fixed periphery, the vessel wall does not stretch / expand sufficiently due to stiffness and / or other non-compliant factors, and generally, the maximum area / volume of the vessel can exist / be achieved when the vessel wall forms a circular cross-sectional shape. Figures 4-1 and 4-2 show vessels with circular and non-circular axial cross-sectional shapes, respectively.

[0036] Figure 4-1 shows its area A c An exemplary blood vessel 91 (blood vessel 91 in Figure 4-1) generally has a circular cross-sectional shape, such that the value is maximized with respect to a given perimeter / wall length Pa. a (Identified as) indicates. In a circular configuration, diameter d a This is substantially constant at all angles around the axis of the blood vessel. The circular shape of the blood vessel 91a may be set or tolerated by the shape of the stent 93 implanted within the blood vessel.

[0037] Deviating from the circular cross-sectional shape can generate a cross-sectional area / volume of the blood vessel that is less than the maximum area A shown in FIG. 4-1. For example, FIG. 4-2 shows a blood vessel 91 (identified as blood vessel 91b in FIG. 4-2) having a shape similar to an oval / ellipse, which has a cross-sectional area A smaller than the area Ac having the same vessel wall / length P c For example, FIG. 4-2 shows a blood vessel 91 (identified as blood vessel 91b in FIG. 4-2) having a shape similar to an oval / ellipse, which has a cross-sectional area A smaller than the area Ac having the same vessel wall / length P a For example, FIG. 4-2 shows a blood vessel 91 (identified as blood vessel 91b in FIG. 4-2) having a shape similar to an oval / ellipse, which has a cross-sectional area A smaller than the area Ac having the same vessel wall / length P o For example, FIG. 4-2 shows a blood vessel 91 (identified as blood vessel 91b in FIG. 4-2) having a shape similar to an oval / ellipse, which has a cross-sectional area A smaller than the area Ac having the same vessel wall / length P n For example, FIG. 4-2 shows a blood vessel 91 (identified as blood vessel 91b in FIG. 4-2) having a shape similar to an oval / ellipse, which has a cross-sectional area A smaller than the area Ac having the same vessel wall / length P b For example, FIG. 4-2 shows a blood vessel 91 (identified as blood vessel 91b in FIG. 4-2) having a shape similar to an oval / ellipse, which has a cross-sectional area A smaller than the area Ac having the same vessel wall / length P m For example, FIG. 4-2 shows a blood vessel 91 (identified as blood vessel 91b in FIG. 4-2) having a shape similar to an oval / ellipse, which has a cross-sectional area A smaller than the area Ac having the same vessel wall / length P

[0038] Referring further to FIGS. 4-1 and 4-2, due to the area A of the elliptical blood vessel in FIG. 4-1 being smaller than the area A of the circular configuration shown in FIG. 4-1, transitioning from the circular shape 91a to the non-circular shape 91b can provide a reduction in the area / volume of the blood vessel. Thus, a solution that causes a transition between the circular blood vessel shape and the non-circular blood vessel shape during the cardiac cycle can provide compliance characteristics without requiring elasticity in the vessel wall tissue. o Referring further to FIGS. 4-1 and 4-2, due to the area A of the elliptical blood vessel in FIG. 4-1 being smaller than the area A of the circular configuration shown in FIG. 4-1, transitioning from the circular shape 91a to the non-circular shape 91b can provide a reduction in the area / volume of the blood vessel. Thus, a solution that causes a transition between the circular blood vessel shape and the non-circular blood vessel shape during the cardiac cycle can provide compliance characteristics without requiring elasticity in the vessel wall tissue. c Referring further to FIGS. 4-1 and 4-2, due to the area A of the elliptical blood vessel in FIG. 4-1 being smaller than the area A of the circular configuration shown in FIG. 4-1, transitioning from the circular shape 91a to the non-circular shape 91b can provide a reduction in the area / volume of the blood vessel. Thus, a solution that causes a transition between the circular blood vessel shape and the non-circular blood vessel shape during the cardiac cycle can provide compliance characteristics without requiring elasticity in the vessel wall tissue.

[0039] In consideration of the foregoing, embodiments of the present disclosure provide stent implant devices and associated processes configured to improve compliance to the area of ​​implant reshaping by transitioning the shape / region of the vessel from near circular / circular to far from non-circular / circular and vice versa. Such stent implant devices / processes may also bring about a vessel reshaping effect through the dynamic reshaping of the stent's structural shape in such a way as to generate a change in the shape of the vessel, which is implanted to generate a change in vessel area / volume between the systolic and diastolic phases of the cardiac cycle. Obstruction / absorption of trapped blood from around the non-circular stent segment may increase the blood vessel reshaping capacity of the stent implant, otherwise trapped blood may interfere with the reshaping capacity of the stent on the vessel. The term “stent” is used herein in accordance with its broad and common sense and refers to any device configured to be implanted in the lumen of a vessel, the device having a tubular morphology that forms a lumen through which blood can flow.

[0040] Embodiments of the present disclosure provide a biased stent-type implant configured such that, with respect to at least a portion / segment of its longitudinal direction, the first diameter of the stent is larger along the long axis than the second diameter of the stent along the short axis, and such stent is configured to transition to a more circular shape when intravascular pressure overcomes the non-circular bias of the stent and pushes the stent wall into a more circular configuration.

[0041] Figures 5A and 5B show perspective and axial views, respectively, of a non-circular stent 500 according to one or more embodiments. Although not shown for clarity in Figures 5A and 5B, it should be understood that the stent 500 may include one or more captured blood drainage / suction features / means adapted to facilitate the removal of blood between the stent and the target vessel wall. Any description of any exemplary drainage and / or suction element / feature of any embodiment in this disclosure can be understood to be implementable in exemplary stents, such as those shown in Figures 5A and 5B. The stent 500 shown may represent a non-circular segment of a stent implant having one or more circular portions / segments, as described in detail herein.

[0042] The stent 500 may be formed of a tubular frame 531 that forms walls around an axial channel 549, thereby defining the channel 549. As described herein, the frame walls 531 of the stent 500 may be considered as a single circumferentially wound wall, or as comprising multiple walls or wall segments. For example, with respect to elliptical stents and other non-circular stents, as shown in Figures 5A and 5B, such stents have a principal axis / dimension A of the stent. maj The side wall segments 525 extending along the relatively long side of the stent, generally aligned with the orientation, and the end wall segments 527 that can connect the side wall segments 525 on the main axis end of the stent 500, can be considered to include the orientation and the side wall segments 525 extending along the relatively long side of the stent, and the end wall segments 527 that can connect the side wall segments 525 on the main axis end of the stent 500. s The side wall 525 may be outwardly curved / concave. The side wall 525 may be outwardly curved / deflected in any of the following states: static, unpressurized, or under hoop / wall stress on the frame 531. For example, the side wall 525 may be curved / deflected outward when the side wall 525 is on axis A of the stent 500. s It can bend outward, appearing concave from one perspective and protruding from the outside of the stent 500.

[0043] Certain stent shapes, including circular, non-circular, elliptical, peanut-shaped, and other shapes of stents, are described herein. Naturally, such descriptions of stent shapes refer to the shape of the axial cross-section of the stent, as shown in the diagram of Figure 5B. Although elliptical and peanut-shaped stents are described, it should be understood that the principles of this disclosure may relate to stents having any non-circular shape in at least some of their configurations (e.g., relaxed / biased configurations). Descriptions of stents in relaxed or biased configurations should be understood to relate to configurations that the stent naturally assumes in the absence of tension on the stent wall(s) from external forces (e.g., ambient fluid pressure, physical contact forces, etc.). For example, the biased / relaxed shape of a stent may be due to the shape memory of the stent and / or its frame.

[0044] Stent 500 may be considered an elliptical stent with respect to the shape of its axial cross-section, as shown in Figure 5B. The term “elliptical” is used herein in its broad and ordinary sense and may be used substantially interchangeably with the terms “elliptical” and / or “major elliptical” as used similarly in their broad and ordinary sense. The term “elliptical” may also be used to refer to any non-circular closed curve having a major axis and a minor axis, where the major axis is greater than the minor axis. With respect to “elliptical” shaped stents disclosed herein, such stents may have relatively flat minor axis sidewalls (compared to curved major axis endwalls), and the sidewalls may be bent radially outward and / or deflected / curved radially inward to produce external recessed surfaces and internal protruding surfaces within such sidewalls (e.g., forming a peanut-shaped stent). The principal axis wall of an elliptical stent as described herein may be considered the wall portion of the stent that penetrates the axial center of the stent and intersects the principal axis of the stent. The minor axis wall of such an elliptical stent can be considered a wall portion that penetrates the axial center of the stent and intersects the minor axis of the stent. The exemplary stents of the present disclosure can be considered to have an elliptical shape, regardless of whether their shape can be defined by an algebraic curve. The exemplary stents of the present disclosure can be considered elliptical stents if the wall(s) of the stent in the axial cross-sectional oblique view(s) are closed or open curves in a non-circular plane, and one or more of their segments / regions may resemble the contour of a portion of an oval. The elliptical stent of the present disclosure is shown with major axis A maj , and minor axis A min These may include one or two axes of symmetry of an ellipse. The axial cross-section of some embodiments of the elliptical stent of this disclosure may resemble the joining of two semicircles on either side of a rectangle, providing a shape reminiscent of a speed skating rink or athletic track. In some contexts, the elliptical stent 500 may be considered a “stadium” shaped stent, or an elongated ellipse.

[0045] The stent frame 531 may comprise a stent wall(s) defining an extended tubular structure having a first end 521a with a first opening 522a. The tubular structure may further comprise a second axial end 521b having a second opening 522b, the lumen / channel 549 extending between the first opening 522a and the second opening 522b and traversing the length L of the stent 500. The frame 531 and / or its wall(s) may include an open-cell structure adapted to expand to fix the stent 500 to the inner (or outer) wall of a vessel, such as by endothelializing the frame 531 into vascular tissue over time, as the frame 531 holds the vessel wall using certain tissue engagement features described in detail herein.

[0046] The stent 500 may be elastically deformable between a first non-circular configuration and a second more circular configuration 500' (see dashed line representation in Figure 5B), and the stent 500 is biased toward the non-circular configuration. In some embodiments, the stent frame 531 may include a shape memory material such as nitinol. Although shown as an elliptical stent, the stent 500 may be any non-circular shape in its relaxed state, such as a triangle, peanut, figure eight, star, clover / leaf, and / or kidney shape.

[0047] The stent 500 may be configured to be delivered percutaneously to a blood vessel 61 in a compression configuration. Once inside the lumen of the blood vessel at the target introduction site, the stent 500 may be configured to expand radially by making direct surface contact with the vessel wall (e.g., the inner wall of an aortic segment). Placement of the stent 500 into the blood vessel may cause at least slight stretching of the vessel wall, such as by the pressure of the long-axis end 527 against the vessel wall. The stent wall, and / or a portion thereof, may be configured to be endothelialized with the vessel wall.

[0048] In the elliptical configuration shown in Figures 5A and 5B, the stent 500 has a minor axis / minor axis diameter d min The major axis / major axis diameter d is substantially larger than maj It may have a cross-sectional area having the principal diameter / d. For example, the principal diameter / dimension dmaj Advantageously, the minor axis diameter / dimension d min The stent may be at least twice as long, or possibly three, four, five, six, or seven times longer. The stent 500 may be configured to increase vascular compliance by applying constant or nearly constant pressure at one or more points along the periphery of the vessel, causing a change in the circumferential shape of the vessel. For example, the vessel may be transitioned from a non-circular and / or less-circular shape to a circular and / or more-circular shape.

[0049] The stent frame wall(s) 531 may consist at least partially of the struts 538 and / or the stent openings / cells 535 between the struts 538. The dimensions and / or shape of the stent 500 may vary depending on the specific application and / or the anatomical structure of the target implantation site. For stents configured for deployment into the aorta, the length L may be 1 to 30 cm, and in a biased elliptical / diastolic configuration, the long axis d maj It may be 1-4 cm (or larger / smaller depending on the specific anatomical structure), and the short axis d min The major axis d maj It may be 20 to 50 percent of that. However, size and / or shape are also within the scope of this disclosure.

[0050] The elliptical shape of the stent 500 might lead one to assume that the vessel wall 61 is more elliptical in shape to match the shape of the stent 500. However, depending on the relative size of the stent 500 to the vessel 61, the vessel 61 does not necessarily conform precisely to the circumference and / or shape of the stent 500, and as the luminal pressure increases and pushes the vessel sidewall away from the frame sidewall 525, gaps 68 may be present and / or formed between the frame 531 and the vessel wall 61. The presence of gaps 68, which periodically form when the pressure decreases (e.g., during diastole) and cause the stent to shift into an elliptical shape, can hinder the desired seal between the stent and the vessel, as the wall 525 is pulled further away from the vessel wall. The presence of gaps 68 reduces the stent 500's ability to reshape the vessel, thereby negatively impacting the effectiveness of the stent 500 in terms of improved compliance. Furthermore, blood may collect and / or stagnate to some extent within gap 68, potentially leading to an increased risk of embolism / thrombus formation.

[0051] When implanted in a blood vessel, the patient's physiological response may react to the Stent 500 as a foreign body. For example, macrophages may accumulate around the stent, and nearby smooth muscle cells may proliferate and cover the stent. Over time, a new endothelial layer may form on the stent, which may inhibit thrombus formation. In addition to preventing embolism / thrombus formation, endothelialization can enhance the stent's ability to reshape the target vessel by strengthening the physical bond between the stent and the vessel, thereby reducing the presence of gaps that form between the stent and the vessel wall when the stent wall is pulled away from the vessel wall as the stent wall reshapes into an elliptical / non-circular shape. Tissue overgrowth may be promoted through contact between the stent frame and the vessel wall. Embodiments of the present disclosure provide a device that facilitates contact between a non-circular stent frame and a vascular wall by emptying blood trapped in a gap 68 and drawing the vascular wall 63 closer to / in contact with the stent frame 531, thereby increasing the effectiveness of the stent in terms of reshaping / enhancing compliance.

[0052] The stent 500 may be biased toward the elliptical and / or other non-circular relaxation / expansion configurations shown (shown by solid lines in Figure 5B), and when subjected to mechanical forces associated with high lumen pressure, its short axis d min The system may be configured to responsively convert to a more circular systolic configuration (shown by a dashed line in Figure 5B) so that the major axis dmaj approaches the major axis d maj This may be equal to the above. As in any of the embodiments disclosed herein, the stent 500 may be configured to deflect from an elliptical to a more circular shape in the presence of a threshold blood pressure level greater than 80 mmHg, such as a blood pressure level greater than 90 mmHg (e.g., 90–120 mmHg).

[0053] The transition of the stent from an elliptical to a more circular stent shape 500' (shown by a dashed line in Figure 5B) allows the energy to be stored in the stent frame 531 (e.g., its elastic and / or shape memory device) so that as the frame transition returns to the elliptical shape 500 as the pressure decreases, the energy is returned to the blood circulation within the vessel wall and thus the vessel segment.

[0054] For example, in the case where the stent frame 531 is covered internally and / or externally by a liquid-tight cover (not shown in Figures 5A and 5B for visual clarity), the openings of the cells 535 of the frame 531 may be closed, allowing fluid to pass through and preventing the blood in the vessel 61 and the channels 549 of the stent 500 from transmitting pressure through the frame 531. Thus, the intraluminal pressure in the flow channels 549 of the stent 500 loads the frame 531 (not directly against the vessel wall 63), causing it to reshape. The blood pressure-induced force on the covering and / or stent frame 531 can increase the hoop stress on the frame 531 and / or covering, which can force the frame 531, and together with it the vessel 61, to take on a more circular shape. As the pressure in the channels 549 increases (for example, in relation to the systole of the cardiac cycle), the plastically deformable nature of the stent frame 531 causes the side walls 525 of the frame 531 to deform along their long axis dimension A maj This allows for the shortening of the stent 500 and its outward pushing. When the side wall 525 is deflected outward, the channel 549 takes on a more circular cross-sectional shape.

[0055] Figures 6A and 6B show perspective and axial views, respectively, of a non-circular stent or stent segment 200 having inwardly deflected sidewalls 225, according to one or more embodiments. The stent 200 may represent an exemplary implementation of any non-circular / elliptical stent / stent segment or part(s) thereof disclosed herein. The shape of the stent 200 is such that the short-axis (e.g., relatively flat and / or long) sidewalls 225 are centered on axis A of the stent 200 in a relaxed state. s The only difference is that it deviates more significantly toward the axial direction from the stent 500 shown in Figures 5A and 5B. The resulting shape may resemble an hourglass and / or peanut shape with respect to the axial cross-section shown in Figure 6B. The stent 200 may have a major axis diameter / dimension that is larger than the minor axis diameter / dimension of the peanut cross-section.

[0056] In some embodiments, the stent 200 forms an external recessed surface / internal protruding surface / morphology relative to the short-axis side wall 225, and the long axis A maj The minor axis dimension d is not constant along the dimensions. min It can be biased to have a shape having a diameter / dimension d at / to the end portion of the short axis side wall 225. min2 Its diameter dimension d at the center is smaller than min1 (Long axis dimension A) maj It may have (for). Non-circular stents of the present disclosure having externally recessed / internally protruding short-axis sidewalls, as shown in Figures 6A and 6B, are referred to herein as peanut-shaped stents, and such peanut shapes may be considered variations of elliptical or elliptical-shaped stents as described herein. The inwardly deflected wall 225 allows for transitional reshaping between a peanut shape, an outwardly bent elliptical shape, and ultimately a circular / more circular shape, which may be shown as a dashed circular stent shape 200'.

[0057] Compared to the elliptical stent 500 in Figures 5A and 5B, the peanut-shaped stent 200 may have a tendency to form a larger gap 68 between the short-axis side wall 225 and the vessel wall 61 due to the inward deflection of the wall 225 away from the vessel wall. That is, the tendency of the stent side wall 225 to pull away from the vessel wall 63 may be relatively high, and therefore, without tissue bonding between the vessel wall 63 and the stent wall 225, the reshaping ability / function of the stent 200 may be impaired / hindered, at least partially. Furthermore, if a gap 68 exists between the stent wall 225 and the vessel wall 63, blood may collect and stagnate in such a space, presenting a risk of embolism and / or hindering the outward deflection of the stent wall 225 for circulation during the systolic phase of the cardiac cycle. Therefore, promoting tissue proliferation of the stent wall 225 may be particularly important with respect to the peanut-shaped stent.

[0058] In some implementations, the stent devices of this disclosure include a stent / frame portion having a circular / cylindrical relaxed shape / form, such stent portion can be integrated in some way with an elliptical portion(s) of the stent, the circular portion(s) of the stent function to firmly hold the stent in place within a blood vessel, while the elliptical portion(s) of the stent can function to increase blood flow through the stent (e.g., diastolic flow) as the elliptical stent portion transitions between an elliptical and circular / cylindrical configuration in response to changes in pressure conditions, which is described in detail herein.

[0059] Figures 7A–7D show perspective, side, and axial views of a stent 400 having a circular end portion 440 and a non-circular (e.g., elliptical) inner portion 420, respectively, according to one or more embodiments. Stent devices having a circular axial end portion that provides direct circular contact with a blood vessel at the end of the stent can particularly benefit from the implementation of captured blood removal features disclosed herein with respect to its non-circular inner portion(s). For example, blood collection / stagnation outside such inner stent portion can be reduced and / or eliminated through the effective implementation of fluid drainage features disclosed herein.

[0060] As described in detail throughout this disclosure, elliptical shapes and other non-circular stents can be used to improve the compliance characteristics of a target vessel or vascular segment. As mentioned above, various hemodynamic considerations may necessitate the implementation of such stents in a manner that a hemostatic seal is present / promoted on the axial end of the stent. Furthermore, depending on the original circular / cylindrical shape of the vessel, elliptical stents in some embodiments may not fit as firmly into the target vessel compared to conventional circular / cylindrical stents of the same size. For example, while circular / cylindrical stents can generally distribute contact with the vessel wall more uniformly around their periphery, preventing contact between the stent and the vessel from concentrating at specific contact points around the stent, elliptical stents, as described in detail above, may tend to contact the vessel primarily at the axial end of the elliptical stent morphology. Additionally, the short-axis sidewalls of elliptical stents become separated from adjacent vessel walls, trapping blood between the stent and the vessel wall and hindering vessel regeneration. Therefore, elliptical stents according to embodiments of this disclosure can benefit from the blood removal features and processes disclosed herein to prevent / solve blood collection between the stent and the blood vessel wall.

[0061] The stent 400 includes circular stent portions 440a, 440b associated with each axial end of the stent 400. Although the circular portions 440 are shown on both axial ends of the stent 400, the circular-elliptical stent device of this disclosure may, in some cases, include only a single circular portion on one end of the device. The circular stent portions 440 may have any preferred or desired axial length. In some implementations, the circular portions 440 have a shorter length (dimension L) than the elliptical portions 420. For example, the elliptical portions 420 may have a length at least twice that of any of the circular portions 440, or twice the combined length of the circular portions 440.

[0062] The circular portion 440 may be formed in part of the stent frame 431, which may be formed integrally with the frame portion forming the elliptical portion 420 of the stent 400. For example, the frame 431 may transition between the circular shape of the circular portion 440 and the elliptical shape of the elliptical portion 420. The frame 431 may transition in a relatively smooth / stepwise manner from the shape of the elliptical segment 420 to the circular shape of the circular segment 440 in the transition portion / segment 450 of the stent 400. That is, with respect to the flat / long side wall 425 extending along the long axis dimension of the elliptical portion 420, the diameter of the frame 431 moves axially from the elliptical portion 420 toward the circular end portion 440, corresponding to the narrow minor axis diameter d of the circular portion 440. min From, the circular diameter d x It can transition to. Furthermore, with respect to the curved / short end wall 427 of the elliptical portion 420 that curves around the long axis end of its elliptical form, the diameter d associated with it maj The relatively long dimension d maj From there, a relatively short circular diameter d moves from the elliptical portion 420 through the transition portion 450 to the circular portion 440. x It can transition to this. In some embodiments, as shown in Figures 7A-7D, the diameter d of the circular portion 440 x The major axis d of the elliptical portion 420 maj It may be smaller than the minor axis d of the elliptical portion 420. min It can be larger than that.

[0063] As shown in Figure 7A, the stent 400 may include a cover 445 shown on the outer surface of the stent 400, but as with other embodiments of the present disclosure, it should be understood that such a cover 445 may be positioned within and / or without the frame 431 on its inner / diameter. For clarity, the cover 445 is shown only in Figure 7A. The stent frame 431 and cover 445 are shown in Figure 7A, but the cover provides a fluid-sealing surface against which pressurized blood in the channel 449 of the stent 400 can be pushed to reshape the elliptical portion 420 of the stent 400, and in some embodiments the stent 400 has a fluid-sealed planar / sheet form in one or more of its portions, and such planar / sheet form provides the structure / frame of the stent 400 and serves as an alternative to the column-based frame 431 and cover 445 shown.

[0064] The stent 400 is formed by a central / internal elliptical segment 420, which assumes an elliptical or other non-circular shape, at least in its free / relaxed state, and both ends of the stent have a circular shape to fully engage with the surrounding vessel wall. In some implementations, the end portions 440 may be relatively large to conform to and press against the vessel wall, which can improve hemostasis and thereby restrict blood flow so that it passes only through the lumen 449 of the stent. The oversize of the circular portion 440 relative to the original vessel may further help the stent 400 resist movement in any axial direction.

[0065] The stent 400 and / or its frame 431 have the same circumference P as the elliptical portion 420 in the circular portion 440. c It may have (the surrounding P shown in Figure 7D) o ). In some implementations, the circumference P of the circular portion 440 o This is the periphery P of the non-circular portion 420. c Larger than. The transition segment / part 450 may similarly have the same circumference as the end 440 and the elliptical 420 segment. Circumference P of the circular part 440 cThe target vascular segment may be selected to match the surrounding area. For example, surrounding P c The circumference of the stent can be within 10% of the circumference of the target vessel within the transplantation area. c The stent may be slightly larger than the circumference / periphery Pc of the target vessel before deployment of the stent 400, thereby promoting secure attachment of the stent 400 to the vessel.

[0066] When the stent 400 is implemented with the cover 445, the circular end portion 440 can function as a funnel, restricting blood flow through the channels of the inner portion 420 and preventing it from flowing to the lateral apex of the inner portion 420. However, since the circular end portion 440 does not need to be configured to change shape throughout the entire cardiac cycle as pressure changes, such a portion may not contribute to the stent's compliance enhancement and vessel reshaping effects. Furthermore, the circular shape of the end portion 440 can allow the end to function as a stationary harness portion, restricting the movement of the central / inner portion 420 between systole and diastole.

[0067] The removal of trapped blood may be particularly beneficial for stents that include a peanut-shaped stent segment due to the potentially larger gap volume between the peanut-shaped stent segment and the blood vessel wall from which blood can be trapped. Figures 8A–8D show perspective, side, and axial views of a stent 800 having a circular end portion 840 and a non-circular (e.g., peanut-shaped) inner portion 820, respectively, according to one or more embodiments.

[0068] The stent 800 may have any of the features disclosed above in relation to the stent 400 in Figures 7A-7D. However, with respect to the inner portion 820 of the stent 800, such portion may have a cross-sectional axial shape similar to a peanut shape, as disclosed in Figures 6A and 6B. Similar to the stent 400 in Figures 7A-7D, the stent 800 may include a circular axial end 840 and a transition portion / segment 850 that transitions the shape of the stent 800 between the circular end 840 and the peanut-shaped inner portion 820.

[0069] The inner portion 820 may have any preferred or desired length and may comprise an inwardly deflected minor-axis wall 825 connected at the major-axis end 827, as in other embodiments disclosed herein. The inner portion 820 may have any preferred minimum diameter d min1 (See Figure 8D), and / or any preferred or desired maximum minor axis dimension d min2 It may have the following. Furthermore, the deflection curvature and / or angle(s) of the walls 825 / 827 of the inner portion 820 of the peanut shape may have any preferred or desirable parameters. The stent frame 800 may include a solid surface form rather than a structure formed from columns and open cells, as detailed and described herein.

[0070] From the top view in Figure 8C, in some embodiments, the peanut-shaped inner portion 820 is the diameter d of the circular portion 840. x Larger than, large diameter dma j-p It will be clear that it has. Conversely, as shown in the side view of Figure 8B, the minor axis dimension d min2 The diameter d of the circular portion 840 x It may have a value less than . In some embodiments, the circumference P of the circular portion 840. c The peanut-shaped portion 820 and / or at least a portion thereof, the circumference P p This can be substantially equivalent. Therefore, as the peanut-shaped portion 820 transitions to a more circular shape, its cross-sectional shape can resemble that of the circular end portion 840.

[0071] In some implementations, this disclosure relates to variations in stent design having ends and inner portions / segments of different shapes. For example, aspects of this disclosure may provide a stent having an end portion that is not circular, but rather a non-circular shape (e.g., peanut-shaped) that differs from the non-circular shape (e.g., peanut-shaped) of the inner portion of the stent. In such embodiments, one or both ends of the compliance-enhanced stent can be designed as a compliant elliptical portion with respect to its relaxed shape / configuration, which can advantageously contribute to the stent's vascular reshaping function, while maintaining proper sealing to the vessel and functioning during transitions between low (e.g., diastolic) and high (e.g., systolic) pressure stages / states. The shape of such stent ends may further form a smoother shape transition, reducing the possibility of flow turbulence through the stent. Figures 9A and 9B show a stent 900 according to one or more embodiments, having an elliptical end portion 940 with a radially outward deflected / bent minor axis sidewall and an elliptical inner portion 920 with a radially inward deflected / recessed minor axis sidewall (e.g., peanut shape).

[0072] The stent shape of stent 900 in Figures 9A and 9B, which has a peanut-shaped inner portion, may have certain advantages over other stent designs that include a non-compliant rounded end portion. For example, in some designs with a rounded end portion, such an end may not be configured to change shape throughout the entire cardiac cycle and therefore may not contribute to the stent's compliance-enhancing vascular reshaping function, whereas the elliptical end portion 940 of stent 900 may be configured to change shape in a periodic manner, thereby contributing to compliance enhancement. Furthermore, while a rounded end portion may restrict the transitional motion of the central / inner portion of the stent, the elliptical end portion 940 may be less restrictive with respect to the transitional motion of the inner peanut-shaped portion 920 between its relaxed peanut shape and a more rounded configuration. Furthermore, some designs with circular end portions transition relatively rapidly from the circular end to the narrower (e.g., significantly narrower) peanut shape of the inner portion of the stent, which can lead to flow turbulence and significant manufacturing complexities associated with deformation / strain. The transition between the elliptical shape of the end portion 940 and the peanut shape of the inner portion 920 may have less impact on flow and structural design strain / deformation than some circular end stents.

[0073] The stent designs in Figures 9A and 9B may, when implanted in a blood vessel, tend to collect blood in the inner portion 920 within the space, formed by the inward deflection of the short-axis wall 925. Therefore, the fluid removal processes and features disclosed herein may be advantageously implemented to drain and block blood from the space between the stent frame and the blood vessel. Furthermore, advantageously, the elliptical shape of the end portion 940 may be configured / dimensional to maintain contact with the blood vessel along its entire circumference (similar to the circular end portion in the embodiments disclosed herein), thus maintaining a suitable seal against the arterial wall and directing flow into the lumen of the stent through the inner portion 92.

[0074] As described above, various solutions of this disclosure using stents having non-circular segments may be implemented to treat hypertensive patients, such as those with heart failure, by improving aortic compliance through vascular regeneration. As described above, such stent devices may include circular end segments, which may facilitate sealing of the stent implant between the stent and the outer vascular wall. For example, stent implants according to embodiments of this disclosure may be configured as round-elliptical / peanut-round implants, examples of which are shown in Figures 7A–7D and 8A–8D, or as elliptic-peanut-elliptical stents, as shown in Figures 9A and 9B.

[0075] Non-circular stent implants with circular sealing end portions may generally include non-circular inner portions / segments(s) having a short axis smaller / shorter than the short axis of the end segment of the implant, so that a certain volume(s) of blood may be trapped between the outer (and / or inner) cover of the stent implant and the outer vessel wall of the implant within the vessel segment into which the inner segment of the stent implant extends. For example, blood may be trapped between the stent cover and the non-circular / elliptical portion between the end segment of the stent and the inner wall of the vessel. Figures 10A and 10B show a side view and an axial view of a stent implant device 300, respectively, implanted in a vessel 61, with trapped blood 69 collected around the stent implant 300, according to one or more embodiments.

[0076] Stagnant blood that may be present in the gap 68 between the non-circular stent segment 320 and the vessel wall 61 can present certain problems. For example, stagnant blood may pose a risk of thrombus formation in the gap region 68, and such thrombi formed on the stent implant may impair its reshaping function. Furthermore, if thrombus formation dislodges from its location within the gap region 68 and enters the bloodstream, it can lead to myocardial infarction and / or stroke. Therefore, it may be desirable to implement the vascular reshaping stent implant device of this disclosure in a manner that reduces the presence / occurrence of trapped blood 69 between the covered non-circular stent segment and the surrounding vascular anatomical structure 61, thereby reducing the risk of thrombus and / or improving the effectiveness / function of the implant device. Over time, stagnant blood 69 within the gap region 68 may solidify and / or become tissue-like in a manner that effectively thickens the vessel wall 61. Stagnant blood within the gap region 68 can further impair the stent's vascular reshaping effect because, as pressure levels increase, incompressible blood 69 generally occupies the space 68 around the stent frame 331, creating an obstruction to the stent frame's ability to determine its circular shape. For example, the vascular segment 61 may impair compliance properties, thus reducing the vascular's ability to stretch to accommodate both the expanded circularization of the stent frame 320 and the blood 69 trapped outside the stent frame. Consequently, the volume changes generated through stent reshaping during the cardiac cycle may be limited / reduced along with their compliance effect.

[0077] Removal of stent gap fluid As described above, a covered stent with an elliptical segment in its free state can be implanted medially into a vessel (e.g., the aorta) to force the vessel to take on a more elliptical shape under low pressure (e.g., diastole), and as blood pressure increases (e.g., systole), the stent (and with it the vessel segment / section) is forced to take on a more circular shape to restore some compliance to otherwise non-compliant (or poorly compliant) sections. Among the risks associated with implanting certain covered stent implants, when a non-circular stent segment is positioned between the two circular ends of the stent implant, blood may be trapped between the outer (or inner) cover of the elliptical segment of the stent and the vessel wall during deployment, which may be done to provide a seal around the stent and / or to prevent unintended axial movement of the stent after deployment. Blood stagnation in these areas / spaces can lead to thrombosis and / or other complications. Thrombus formation in the area / space surrounding the outer diameter of the non-circular / elliptical segment of a stent implant device can press against the stent, thereby impairing the stent's vascular regeneration function. Furthermore, if the thrombus is removed and leaks into the bloodstream from the trapped space / location, it can lead to myocardial infarction or stroke. Various solutions are presented herein to remove trapped blood from around the non-circular stent segment through various blood flow pathways / features, using active aspiration / suction from the trapped space or blood extrusion / drainage.

[0078] Removal of gap fluid using pipes According to aspects of this disclosure, exemplary stent implant devices may be implemented using blood flow channels / tubes, and suction may be applied to such channels / tubes to aspirate trapped blood from the gap region around the non-circular stent segment. Additionally or alternatively, blood removal through the channel / tube features may be passive or through a discharge flow. Exemplary stent implant devices may include fluid channel / tube features that can be used for removing trapped blood during and / or after stent deployment.

[0079] The removal of trapped blood / fluid can prevent or reduce the presence of gap spaces between the stent and the vessel wall by drawing the vessel wall close enough to the stent implant (e.g., its cover, and / or frame), thereby reducing or eliminating the available space for trapped / stagnant blood to collect outside the stent frame. With the vessel wall drawn close to the stent structure, endothelialization of the stent wall to the vessel wall can, advantageously, occur over time, which can provide an improved vessel-stent connection that facilitates vessel reformation. For example, if a vessel is reformed only through the long axis pushing the vessel, relatively large forces may be required to reform the vessel into the desired elliptical shape. However, if the short-axis attachment / connection between the stent and the vessel occurs in such a manner that the short-axis stent wall provides tension on the tissue wall, relatively little long-axis compression / extension may be required to achieve equivalent vessel volume change / reformation due to the ability of the stent frame to fold the short-axis vessel wall radially inward from the inside. The captured blood can be aspirated or discharged through any type of drainage channel, such as a tube and / or a one-way valve.

[0080] Figures 11A and 11B show side and axial views of a stent implant device 100, each including a fluid suction / discharge tube(s) 110, according to one or more embodiments. Figures 12A and 12B show side and axial views of a stent implant device 100, each having blood passing through an associated fluid suction / discharge tube(s) 110, which provides a discharge channel(s) for the captured blood. The figures in 11A and 12A show a short-axis side view of the stent implant 100 to relatively clearly show a gap region 68 between the short-axis wall / side portion 125 of the non-circular stent frame portion 120 and the vascular wall 63 in such a region. The gap region(s) 68 can be considered a space on or outside the outer diameter of the stent segment 120. The removal of blood 69 through the outlet channel / tube 110 can be performed via active suction / aspiration or by drainage through dilation of the short-axis wall 125 of the stent 100.

[0081] The implant 100 includes one or more suction / passage tubes 110, which may be components of a delivery system used in conjunction with the implant 100. Alternatively, the tubes 110 may be separate from the delivery system. For example, the tubes 110 may be positioned between the stent 100 and the vessel wall 61 before or during stent deployment. The stent implant 100 includes a cover 145, which may be fluid / liquid-tight. The “liquid-tight” cover features disclosed herein may not be completely fluid-blocking in some implementations, but may be at least partially impermeable, non-porous, and / or inhibit or block at least a certain type of fluid passing through it.

[0082] The inner opening / end 112 of the tube(s) 110 may be positioned in fluid communication with the trapped blood volume between the inner segment 120 of the stent 100 and the vessel wall 63, so that the application of a vacuum force (or other negative pressure) through the tube(s) 110 can function to draw out the trapped blood 69. In some implementations, once the stent 100 is fully deployed, suction can be applied to the tube(s) 110 in such a manner that the trapped blood region 68 is sealed and exposed only to the tube(s) 112. Suction of the blood 69 through the tube(s) 110 may result in it being drawn close to the stent, such as until the vessel wall 63 is in full contact with the outer surface of the stent.

[0083] The tube(s) 110 may have any preferred or desired shape and / or configuration. In some embodiments, the implant 100 is implemented with a single suction / outlet tube 110. Alternatively, multiple tubes may be arranged around the circumference of the stent 100. In some embodiments, a ring-shaped tube surrounding at least a portion of the stent 100 may be implemented.

[0084] Once the aspiration / removal of blood 69 from region 68 is complete, the tube(s) 110 may be optionally withdrawn from the patient's body, leaving the stent 100 implanted in place around the stent without the tube(s) 110. After the aspiration / removal of fluid 69, the vessel wall 63 may be positioned and / or fitted relatively closely around the stent body. In some implementations, the tube(s) 110 may remain in place around the stent 100. For example, after the aspiration / removal of the captured blood 69 (or at least a portion thereof), the tube(s) 110 may be detached from the delivery system and sealed. The sealing of the tube(s) 110 may also be achieved using one-way valves associated with each of the tube(s) 110's flow paths, such valves may be configured to block or obstruct flow toward the axial center 101 (e.g., toward the gap region 68), while allowing flow to pass in a direction 102 away from the axial center 101 of the stent 100.

[0085] The tube(s) 110 may be positioned on the outer diameter of the circular end portion 140 of the stent 100. For example, the tube(s) 110 may be positioned on the outer diameter of at least a portion of the implant 100, the stent frame, and / or cover. The tube(s) 110 may be integrated with the frame, cover, and / or other features or aspects of the stent implant 100, or they may be separate components positioned / positioned on the outer diameter of one or more ends of the implant, for example, the circular portion 340. In some implementations, the tube(s) 110 may be associated with only one axial side of the implant 100, such as the proximal side, with respect to a delivery system used to deploy the implant 100 and / or perform aspiration through the tube(s) 110. For example, blood 69 may be aspirated through one axial side of the implant 100, the side on which the delivery system or other instrument deploys the implant 100 and / or aspirates / sucks the blood 69.

[0086] The tube(s) 110 may be attached to or fixed to the stent 100 in some way by suture, clamp, adhesive bonding, or other attachment means or mechanisms, which may facilitate secure attachment to the stent body / frame and / or prevent the tube(s) 110 from becoming detached and / or moving after deployment. In some implementations, the tube(s) 110 are held in place through frictional compression between the stent 100 and the vessel wall 61.

[0087] The stent implant 100 may be deployed together with a tube(s) 110 positioned in contact with it, or the tube(s) 110 and the stent 100 may be deployed separately. For example, in some implementations, one or more tubes may be deployed in the vessel 61, and then the stent / frame 100 may be expanded into the vessel 61 in a position such that the tube(s) 110 extend inward 103 within a gap region 68, beyond the axial end 149 of the stent frame 100, in its inner portion, outside the short-axis wall / segment 120 of the stent 100.

[0088] The tube(s) 110 may be used to remove fluid from the gap region 68 to improve the function of the stent implant device 100 in its non-circular inner portion 320. Removal of blood through the tube(s) 110 may be carried out in any preferred or desired manner, such as by active drainage and / or aspiration of blood 69 through the tube(s) 110. For example, with respect to aspiration, as shown in Figures 12A and 12B, a cross-sectional force may be applied to the tube(s) 110 to aspirate blood 69 in the gap region 68 through the tube(s), thereby drawing the vessel wall 63 closer to the stent frame. Suction / aspiration through the tube(s) 110 may be achieved using an instrument / system separate from the delivery system used to deploy the stent implant device 100 and / or the tube(s) 110, or the delivery system used for stent deployment may include a function for aspirating fluid. Aspiration may be performed after the deployment of the stent implant device 100, and the collected blood 69 captured in such a process may be drawn out through the tube(s) 110 after the deployment of the stent implant device 100 to reduce the gap 68 between the stent frame and the blood vessel wall 61, at least in the area of ​​the inner portion 120.

[0089] In some implementations, blood 69 may pass through the tube(s) 110 through drainage by expanding and / or reshaping the stent frame, at least in the inner portion 120. For example, after and / or during the deployment process of the stent implant device 100, the short-axis wall 125 of the stent frame may expand from its biased, reduced diameter, causing the stent frame to round and / or fill the space 68 between the stent 100 and the vessel wall 61, thereby reducing the available gap space 68 on the outer diameter of the stent 100 and forcing the blood 69 occupying such space to be drained out through a path of least resistance, such as through the tube(s) 110.

[0090] In some implementations, the tube(s) 110 may be equipped with a one-way valve configured to allow blood / fluid to pass through the tube(s) 110 out of the gap region 68, while preventing blood from re-entering / re-entering the gap region through the tube(s) 110.

[0091] As shown in Figures 12A and 12B, a process may be carried out to remove blood 69 from the gap region 68, drawing the vessel wall 63 into the stent body 100 and improving the reformation ability of the stent 100 relative to the vessel 61 around the inner segment 120. After the removal of the gap fluid / blood 69, the tube(s) 110 may be maintained in place on the outer diameter of the stent 100 or may be removed. In implementations where the tube(s) 110 are removed, the stent 100 may provide a seal to its circular end portion 140 after the removal of the tube(s) 110. For example, the presence of the tube(s) may cause radially inward deflection 104 of the stent frame 100, as shown in Figure 11B, and the shape memory / configuration of the circular portion(s) 140 of the stent 100 may cause such portion to expand into a more circular / continuous expanded form upon removal of the tube(s) 110. Alternatively, the presence of the tube(s) 110 may cause a deviation of the outer surface of the vessel wall in the region of the tube(s), and the removal of the tube(s) 110 may allow the vessel 61 to take on a more continuous circular shape in such region.

[0092] The tube(s) 110 may have any preferred or desirable shape and / or length. For example, although shown as having a circular cross-sectional area, it should be understood that the tube(s) 110 may have any preferred or desirable cross-sectional area, such as elliptical, rectangular, rhombic, or other shapes. Furthermore, the length of the tube may extend to any distance beyond the axial end 149 of the stent 100 and / or within the gap region 68. In some implants, the tube(s) 110 may be deflected radially inward in the transition region 150 of the stent 100, as shown, to more closely conform to the shape of the stent frame in its non-circular segment 120 and / or transition segment. That is, the axially inward end of the tube(s) 110 may be deflected radially inward, as shown. A suction pump or similar device may be used to draw in the captured blood 69 through the tube(s) 110.

[0093] The tube(s) 110 may extend within a delivery system or other device configured to perform suction / aspiration through the tube(s) 110. In such embodiments, removal and / or withdrawal of the suction system / device may involve pulling the tube(s) 110 away from the patient, around the stent segment 140. In some implementations, the tube(s) 110 are cut off in the vessel outside / beyond the axial end 149 of the stent. In such implementations, the tube(s) 110 may remain in the vessel with the stent 100 after implantation. Suction / aspiration may be performed using any suction / vacuum device known to those skilled in the art.

[0094] Gap fluid discharge using a one-way valve Embodiments of the present disclosure provide a stent implant device comprising specific one-way valve features for removing trapped blood radially outward from a non-circular segment of a covered stent implant device, the valve features being able to reduce the risk of thrombus formation due to blood stasis in the area surrounding the stent segment. The blood removal valve features of the present disclosure may comprise a one-way valve positioned around at least a portion of an end segment (e.g., a circular end segment) configured to allow blood flow from the trapped volume to the bloodstream, and such blood drainage may occur when the non-circular stent segment transitions to a more circular shape during systole, thereby pushing blood through the valve(s).

[0095] Figures 13A and 13B show side and axial views of a stent implant device 600, each including a fluid discharge valve(s) 610, according to one or more embodiments. Figures 14A and 14B show side and axial views of a stent implant device 600, each having blood passing through an associated discharge valve(s) 610, which functions as a discharge channel for the outflow of captured blood 69. The stent implant 600 may be a sealed / coated implant, as described in detail herein. Removal of blood 69 through the discharge channel(s) / valve(s) 110 may be via discharge through expansion of the short-axial wall(s) 625 of the stent 600.

[0096] The stent implant includes one or more one-way valves 610 which may be associated with one or both axial ends of the stent implant device 600. The one-way valves 610 may be positioned on and / or associated with the circular portion 640 of the stent implant 600, which may have configurations described in relation to any embodiment disclosed herein, such as an implant having a circular end portion configured to provide fluid sealing with a target vessel, and an inner non-circular segment 620 which may have an elliptical or similar shape. The valves 610 may completely surround the outer diameter of the end segment 640, or only a portion thereof.

[0097] One-way valves 610 may be positioned around at least one end 640 of the covered stent 600. Valves 610 may be positioned between the outer diameter / edge of the stent and the inner wall of the blood vessel. One-way valves 610 may optionally surround the entire circumference of a stent segment 640 or one or more arcs / parts thereof. In some implementations, valves 640 may extend only to the short-axis side / part of the stent 600, or primarily to the short-axis side / part.

[0098] The valve(s) 610 can be in fluid communication with blood 69 located within the gap(s) 68 on its axially inward side. The blood 69 trapped between the stent wall(s) and the vessel wall can apply fluid pressure to at least a portion of the valve(s) 610. Thus, during systole, or other pressurized conditions, when the stent short-axis wall(s) 625 expands outward, as shown in Figures 14A and 14B, the resulting increased pressure in the trapped blood 69 may be sufficient to open the valve(s) 610 and push at least a portion of the trapped blood 69 through it. Thus, each systolic cycle can function to empty an additional volume of trapped blood 69, which can then retract the vessel wall 63, which has been drawn out near the stent 600, such as until it is in potentially full contact with the outer surface of the stent 600. One or more one-way valves 610 may be mounted around only one axial end of the stent, or one or more one-way valves may be mounted around both ends of the stent.

[0099] The one-way valve(s) 610 may have any preferred or desirable shape or configuration. For example, in some implementations, as shown in Figure 13B, the valve(s) 610 may extend along the outer diameter / periphery of the circular portion(s) 640 of the stent segment(s) 640. Such valve(s) 640 may extend around such segment(s) or around one or more of its arcs. The valve(s) 610 may be concentric with the circular portion(s) 640 of the stent segment(s) 640. The valve(s) 610 may be configured as a one-way valve that can prevent / prevent blood from passing through the gap(s) 68 and exiting the vascular segment extended by the stent, but can prevent / prevent blood from passing through into the gap(s) 68 from the axial outside of the stent implant device(s) 600. Therefore, when blood is discharged from the gap region(s) 68, such gap region(s) can no longer be occupied by the volume of such blood, thereby promoting the collapse of the empty gap region(s), thereby allowing the blood vessel wall to form more closely with the stent wall and promoting the reshaping function of the non-circular stent portion(s) 620.

[0100] The one-way valve(s) 610 may include flaps configured to deflect in one axial direction and radially inward or outward, while deflection in the other axial direction beyond a specific point of contact with the vessel wall is prevented or obstructed. For example, if the pressure in the gap(s) 68 increases, such pressure may press the blood(s) 69 against the one-way valve(s) 610, allowing the blood(s) 69 to pass through and thereby discharge the blood(s) 69 from the gap(s) 68. Such an increase in pressure may be achieved by any available means or mechanism. For example, as disclosed in detail herein, the inner portion 620 of the stent 600 may be expanded relative to its short axis, thereby reducing the gap(s) 68 and pushing / discharging the blood(s) 69 occupying the gap(s) 68 through the one-way valve(s) 610 away from the stent 600.

[0101] The one-way valve(s) 610 may have one or more valve leaflets, skirts, flanges, lips, or similar features. The valve(s) 610 may include any preferred or desirable, at least partially flexible material, such as biocompatible rubber / polymer (e.g., polyurethane, silicone, etc.). The valve skirt(s) 610 may be axially deflected and mounted at an angle that produces a one-way opening range / function. The radial size of the valve(s) 610 may be advantageously limited to less than 20% of the diameter of the stent segment(s) 640 to reduce interference with the channel area and / or sealing features of the stent.

[0102] In some implementations, valve features 601 (see Figure 13B) may be implemented within the cover 645, such as in slits / cuts within the cover between the stent frame 631's cell supports 638, thereby allowing captured blood to flow into the internal flow channels 669 of the stent 600 in response to increased pressure in the gap regions 68, such as in relation to the systolic rounding of the stent segment 620. For example, a valve leaflet, or similar structure 601 implemented in the cover 645, or in other parts / components of the stent 600, may open into the flow channels 669 of the stent 600, but may be configured to at least partially prevent or block backflow into the gap regions 68 through such features 601.

[0103] Gap fluid discharge using balloon inflation Various solutions for removing trapped blood from around a non-circular stent segment, which can provide an antithrombotic function to the stent implant device, may include additional components associated with the stent implant device, such as tubes, valves, or similar, and / or manipulation of the stent implant in a manner that pushes the trapped blood out from around the stent. Examples of such solutions may include / involve an inflatable balloon, which, when inflated, can deform / reshape the non-circular stent segment in a manner that increases its short axis, thereby rounding the stent segment and reducing the gap area / volume between the stent segment and the blood vessel, thereby pushing out the blood occupying such space from around the stent segment. In some embodiments, a balloon device having an "O" or donut shape may be utilized, which has a central opening / opening through which blood can flow after the balloon is inflated, thereby preventing / reducing blockage of the blood vessel during balloon inflation / expansion.

[0104] Figures 15A and 15B show side and axial views, respectively, of a stent implant device 700 associated with a fluid discharge balloon 715, according to one or more embodiments. Figures 16A and 16B show side and axial views, respectively, of a stent implant device 700 having a fluid discharge balloon 715 expanded within its internal channel 749, according to one or more embodiments. As described above, for stent implant devices including a liquid-tight cover, the blood discharge / suction features disclosed herein may reduce the risk of blood stasis radially outward of the stent. For stent implant devices without a liquid-tight cover, the stent frame may be coupled to the vessel wall in a manner that allows the vessel wall to function as a blood flow channel conforming to the shape / morphology of the stent frame, using balloons and other expansion devices disclosed herein configured to round / expand non-circular stent segments.

[0105] The stent implant device 700 may be implemented in connection with a process involving the inflation of a balloon 715 within the deployed and covered stent 700, the inflation of which may force the captured blood 69 through one or more one-way valves 710 or other flow path features associated with and / or positioned around one or both axial ends 740 of the stent 700. In the illustrated example, the one-way valves 710 disclosed herein are provided around at least one end 740 of the stent 700 (e.g., the proximal or distal end). For example, the valve(s) 710 may be positioned between the outer diameter / edge of the valve and the inner wall of the blood vessel. The one-way valve(s) 710 may optionally surround the entire circumference / periphery of the stent segment(s) 740, or a portion thereof. The implant 700 may include valve features at both axial ends 740, or at only one axial end.

[0106] Alternative blood drainage features providing passages from gap region(s) 68 to the inner channel 749 of the stent 700 and / or to a region 67 axially beyond the stent 700 may be implemented within the scope of this disclosure. Unlike some solutions disclosed herein, the one-way valve(s) may not be configured or designed to open in response to an increase in systolic blood pressure in channel 749 and / or gap region(s) 68, but rather may be designed to open in response to a relatively high pressure in the gap region(s) 68 applied thereto by the inflation of balloon 715.

[0107] In some implementations, fluid communication can be maintained between the opening / passage of the valve(s) 710 and the space 68 in which blood 69 is trapped between the stent wall and the vessel wall. After stent deployment, the balloon 715 can be inflated within the stent channel 749, expanding the stent wall(s) radially outward and forcing the valve(s) 710 open with pressure, pushing the blood 69 toward the valve(s) 710, and the volume of the trapped blood 69 (e.g., substantially all of the trapped blood 69 and over 80% or 90%) is released into the blood flow within the channel 749 and / or into the axially outer region 67 of the stent 700.

[0108] Figures 15A and 15B show the balloon 715 in its deflated state before inflation for the drainage of captured blood, and Figures 16A and 16B show the subsequent inflation of the balloon 715 and the corresponding drainage of captured blood. After inflation of the balloon 715 and drainage of blood 69, the balloon may deflate again, thereby allowing the stent segment 720 to return to its elliptical free / relaxed state, and the vessel wall may be drawn into and / or conform more closely to the non-circular shape of the stent segment 720 if there is no volume of captured blood 69 around it. For example, at least a partial vacuum may be formed between the stent and the vessel, drawing / holding the vessel wall 63 into the stent wall(s) 725, thereby improving the coordination between the reshaping of the stent 720 and the reshaping of the vessel 61 and adding a compliance function thereto.

[0109] In some implementations, the balloon 715 may be provided with an O-shaped cross-section (e.g., donut / torus, or cylindrical donut / torus shape) that defines a central opening / passage 769 in an inflated state through which blood can flow continuously, thereby eliminating the need for rapid pacing during the procedure to drain the trapped blood. Although an inflatable balloon is shown and described, in other embodiments, an internal temporary stent may be expanded within an elliptical stent segment 720 rather than a balloon. A temporary internal stent, for example, can be recompressed and recovered from the patient after expansion to drain the trapped blood 69, or the expanded stent may remain within the elliptical stent segment 720. For example, the expanded stent may degrade over time, and the elliptical stent segment 720 may then be designed / configured to allow it to return to its elliptical free / relaxed state. The shape of the balloon 715 may be considered as a cylindrical torus or donut, which may form an axial blood flow channel through it. As shown, the balloon 715 can be positioned within / inside the inner diameter of the non-circular segment 320.

[0110] The implementation of the stent implant device 700 in Figures 15A, 15B, 16A, and 16B may include any preferred or desirable means or mechanism for draining trapped blood from around the stent segment 720 through a blood flow passage such as a one-way valve, tube, or other passage. That is, any of the embodiments disclosed herein may involve fluid drainage using a balloon-inflatable device / component, as shown in Figures 15A / 15B and 16A / 16B.

[0111] Figure 15A shows a stent implant device 700 deployed in a target vessel 61, having a reformable and expandable balloon 715 positioned within the inner diameter of a non-circular segment 720. The balloon 715 may have any preferred or desirable length and / or shape. For example, the balloon 715 may have a cylindrical shape, and in its expanded configuration, a cylindrical balloon 715 generally has a circular axial cross-sectional shape. However, naturally, other shapes may be implemented within the scope of this disclosure.

[0112] The stent 700 may have one or more donut-shaped balloons positioned within the stent frame. The balloons 715 may be physically attached / fixed to the stent 700, or they may be separate components simply located within or positioned within the stent channel 749. The balloons 715 may be inflatable so as to be inflated within the stent segment 720 to conform to the shape of the inflated / expanded balloon(s) 715, resulting in expansion and / or shaping of the stent segment 720. Although one balloon 715 is shown, some implementations may implement multiple axially offset balloons, and the stent reshaping balloons may be positioned at any axial position of the stent 700, or associated with them, and furthermore, any number of balloons and any position or combination of positions may be arranged. The balloons 715 may be inflated such that the degree of balloon inflation indicates, at least partially, the amount of blood discharged from the region 68. Implementing multiple axially offset balloons may advantageously provide control over inflation in different shapes for different segments / regions of the stent 700 and / or in a continuous manner, facilitating the movement of blood 69 from the captured region 68 toward the axial end 739.

[0113] The balloon 715 may be a hollow, donut-shaped balloon that can be inflated inside the stent 700 after the stent 700 has been deployed within the target vessel 61. The donut shape of the balloon 715 allows blood to flow through it with relatively low flow turbulence, as blood can flow through the central channel 769 of the balloon 715.

[0114] The use of expansion balloons 715 can facilitate conformal contact between the stent 700 and the vessel wall, thereby facilitating intra-tissue growth and / or other attachment or frictional interference between the stent 700 and the vessel wall, and fixing the stent in place at a target location within the vessel. The balloons 715 may extend individually or collectively to substantially the entire circumference and / or the entire length of the stent 700, or only to a portion of the circumference and / or a portion of the length. The balloons 715 may contain any suitable or desirable material. For example, the balloons 715 may contain compliant or non-compliant materials (e.g., polymers). With respect to any blood drainage balloon disclosed herein, such balloon may, advantageously, comprise or be associated with one or more removable unidirectional expansion nozzles that are fluidly coupled to and / or an external delivery device that can be used for deployment purposes.

[0115] The balloons 715 may be pre-attached to the stent 700 before it is deployed into the blood vessel 68, or they may be introduced into the lumen of the stent after its deployment. Furthermore, the balloons 715 may be removable from the stent 700 to allow for the removal of the balloons 715 after they have been inflated for blood drainage.

[0116] After the removal of blood 69, the balloon 715 may be deflated. Deflation of the balloon 715 may be performed to allow for its removal from the blood vessel 61. In some implementations, the balloon 715 may be retained indefinitely after the implantation procedure, after blood drainage, within the stent 700. In such cases, deflation of the balloon 715 may reduce its volume and thereby reduce its impact on blood flow within the blood vessel. In some implementations, the balloon 715 may be attached to the stent by sutures, adhesives, or other attachment means or mechanisms.

[0117] The balloon 715 may be filled with any fluid medium, such as saline or other liquids, which may be preferable to a gaseous medium due to the risk of stroke that may be associated with gas leakage in the event of balloon rupture or other leaks. The balloon 715 may be deployed and inflated as part of a procedure separate from the deployment of the stent 700. In some implementations, the balloon 715 is used to expand the stent 700 from its crimped / compressed delivery configuration when deployed from the delivery system. Alternatively, the stent 700 may be self-expanding. In some cases, it may be beneficial for the balloon 715 to be non-compliant as a means of controlling the expansion and / or shape of the balloon 715.

[0118] Figures 15A and 15B show the stent implant device 700 implanted in the target vessel segment, with the captured blood 69 located in a gap region 68 outside the outer diameter of the non-circular segment 720 of the stent 700. Because the balloon 715 is deflated, the balloon 715 does not initially need to reshape the stent 700 from its non-circular shape. In some implementations, the implant 700 may be deployed with the balloon 715 positioned within it, or alternatively, the balloon may be introduced into the lumen of the stent segment 720 after its deployment.

[0119] Figures 16A and 16B show a balloon 715, which expands to cause the stent segment 720 to become circular, thereby reducing the volume of the gap region(s) 68 and drawing out blood 69 that previously occupied such space(s) 68 from around the stent 700, thereby conforming the blood vessel(s) 61 to the shape of the stent segment 720. When expanded, the entire length of the stent 700 may form a straight cylindrical shape, in contrast to the circular and non-circular combined shapes shown in Figure 15A. The blood 69 may exit the gap region(s) 68 through a one-way valve or tube passage 710, as described in detail herein, and the re-entry of the blood into the space on the outer diameter of the stent implant from outside the stent frame may be prevented or obstructed.

[0120] Additional examples A list of examples is provided below, each of which may include an embodiment of any of the other embodiments disclosed herein. Furthermore, any embodiment of any of the embodiments described above may be implemented in any of the numbered embodiments provided below.

[0121] Example 1: A stent comprising: a first stent segment having a non-circular axial cross-sectional shape in a relaxed configuration; second and third stent segments on either side of the first stent segment, having a circular relaxed axial cross-sectional shape; a liquid-tight cover disposed on at least one of the outer or inner diameters of the first, second, and third stent segments; and a blood flow outlet channel fluid-communicating with a space on the outer diameter of the first stent segment, configured to allow blood flow to pass through the blood flow outlet channel and exit the space axially.

[0122] Example 2: Any embodiment of the stent described herein, in particular the stent described in Example 1, comprising a tube, wherein the blood flow outlet channel is positioned on the outer diameter of the second stent segment.

[0123] Example 3: Any embodiment described herein, in particular the stent described in Example 2, wherein the tube is coupled to a suction pump configured to draw blood through the tube.

[0124] Example 4: Any embodiment described herein, in particular the stent described in Example 3, associated with a delivery system, wherein the suction pump is configured to be used to deploy the stent into a target vessel.

[0125] Example 5: Any embodiment described herein, in particular the stent described in Example 2, wherein the pipe has a one-way valve in its flow path.

[0126] Example 6: Any embodiment described herein, in particular the stent according to Example 2, wherein the axial inner end of the pipe is deflected radially inward toward the outer diameter of the first stent segment.

[0127] Example 7: Any embodiment described herein, in particular the stent described in Example 1, comprising a one-way valve configured such that the blood flow outlet channel allows blood flow in a first axial direction through the one-way valve and blocks blood flow in a second axial direction opposite to the first axial direction.

[0128] Example 8: Any embodiment described herein, in particular the stent according to Example 7, comprising a flap configured such that the one-way valve is deflected away from the axial center of the stent.

[0129] Example 9: Any embodiment described herein, in particular the stent according to Example 7, wherein the one-way valve completely surrounds the outer diameter of the second stent segment.

[0130] Example 10: Any embodiment described herein, in particular the stent according to Example 1, wherein the blood flow outlet channel has an opening within the liquid-tight cover.

[0131] Example 11: Any embodiment described herein, in particular the stent according to Example 10, wherein the opening of the liquid-tight cover is located within a portion of the liquid-tight cover associated with the transition segment of the stent between the first stent segment and the second stent segment.

[0132] Example 12: Any embodiment described herein, in particular the stent according to Example 1, further comprising an inflatable balloon disposed within the inner diameter of the first stent segment.

[0133] Example 13: Any embodiment described herein, in particular the stent described in Example 12, wherein the balloon has an axial blood flow channel.

[0134] Example 14: A method for removing trapped blood around a stent implant, the method comprising deploying a covered stent implant into a blood vessel, wherein the stent implant includes an inner non-circular stent segment; expanding first and second circular end segments of the stent implant to fluidly seal the first and second circular end segments with respect to the blood vessel; and removing trapped blood from the space between the outer diameter of the inner non-circular stent segment and the blood vessel.

[0135] Example 15: Any embodiment described herein, in particular the method of Example 14, wherein the removal of the captured blood comprises aspirating the captured blood through a tube extending along the outer diameter of the first circular end segment.

[0136] Example 16: Any embodiment described herein, particularly the method of Example 14, wherein the removal of the captured blood is performed by causing expansion of one or more short-axis walls of the inner non-circular stent segments, thereby draining the captured blood from the space.

[0137] Example 17: Any embodiment described herein, in particular the method of Example 16, wherein the discharge of the captured blood comprises pushing the captured blood through a tube extending along the outer diameter of the first circular end segment.

[0138] Example 18: The method according to any embodiment described herein, particularly the method according to Example 17, wherein the pipe comprises a one-way valve in the flow path of the pipe.

[0139] Example 19: Any embodiment described herein, in particular the method of Example 16, wherein the discharge of the captured blood comprises pushing the captured blood through a one-way valve associated with the first circular end segment.

[0140] Example 20: Any embodiment described herein, in particular the method according to Example 19, wherein the one-way valve comprises a flexible flange positioned between the outer diameter of the first circular end segment and the blood vessel.

[0141] Example 21: Any embodiment described herein, in particular the method of Example 16, wherein the discharge of the captured blood comprises inflating a balloon into the channel of the inner non-circular stent segment.

[0142] Example 22: Any embodiment described herein, in particular the method according to Example 21, wherein the balloon has a cylindrical torus shape through which an axial blood flow channel is formed.

[0143] Example 23: Any embodiment described herein, particularly the method of Example 22, further comprising deflating the balloon after inflating it and removing it from the blood vessel.

[0144] Depending on the embodiment, certain actions, events, or functions of any process or algorithm described herein may be performed in a different order, added, merged, or completely excluded. Therefore, in a particular embodiment, not all described actions or events are necessary for the practice of the process.

[0145] In particular, conditional language used herein, such as “can,” “could,” “might,” “may,” and “e.g.,” is intended in its ordinary sense unless otherwise stated or understood differently in the context in which it is used, and is generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not. Therefore, such conditional language is not generally intended to imply that features, elements, and / or steps are required in any way in one or more embodiments, or that one or more embodiments necessarily include, with or without input or prompting by the author, logic for determining whether these features, elements, and / or steps are included or performed in any particular embodiment. Terms such as “comprising,” “including,” and “having” are synonymous and are used in their ordinary sense, comprehensively and in an open-ended manner, without precluding additional elements, features, actions, or behaviors. Furthermore, 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" can mean one, some, or all of the elements in the list. Connecting phrases such as "at least one of X, Y, and Z" are understood in context to be used to generally convey that an item, term, element, etc., may be any of X, Y, or Z, unless otherwise specified. Thus, such connecting phrases are not generally intended to imply that a particular embodiment requires the presence of at least one of X, at least one of Y, and at least one of Z, respectively.

[0146] In the above descriptions of the embodiments, it should be understood that various features are sometimes grouped together in a single embodiment, figure, or description for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various embodiments of the invention. However, this method of disclosure should not be construed as reflecting an intention that any claim requires more features than expressly described in that claim. Furthermore, any component, feature, or step illustrated and / or described in a particular embodiment of this specification may be applied to or used in conjunction with any other embodiment. Moreover, no component, feature, step, or group of components, features, or steps is required or essential to each embodiment. Accordingly, the scope of the invention of the present invention disclosed and claimed below should not be limited by the particular embodiments described above, and should be determined solely by a fair reading of the following claims.

[0147] 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 physical properties or order. Therefore, when used herein, sequential terms used to modify elements such as structures, components, and actions (e.g., “first,” “second,” “third,” etc.) do not necessarily indicate the priority or order of the element relative to any other element, but rather generally distinguish the element from other elements having similar or identical names (other than the use of sequential terms). In addition, when used herein, the indefinite articles ("a" and "an") may indicate “one or more” rather than “one.” Furthermore, actions performed “on the basis” of a condition or event may also be performed on the basis of one or more other conditions or events not explicitly stated.

[0148] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as those commonly understood by those skilled in the art in the field to which the exemplary 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 it is understood that they should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0149] Spatially relative terms such as “outside,” “inside,” “upside,” “downside,” “bottom,” “up,” “vertical,” and “horizontal,” and similar terms may be used herein to facilitate explanation in order to describe the relationship between one element or component and another, as shown in the drawings. It is understood that spatially relative terms are intended to encompass different orientations of a device in use or operation, in addition to the orientation depicted in the drawings. For example, if a device shown in the drawings is turned over, a device positioned “below” or “directly below” another device may be positioned “above” another device. Thus, the exemplary term “below” includes both the lower and upper positions. Devices may also be oriented in other directions, and therefore, spatially relative terms may be interpreted differently depending on the orientation.

[0150] Unless otherwise explicitly stated, comparative terms and / or quantitative terms such as “less,” “more,” “greater,” and “same kind” are intended to encompass equivalent concepts. For example, “less” can mean not only “less” in the strictest mathematical sense, but also “less than or equal to.”

Claims

1. It is a stent, The first stent segment, having a non-circular axial cross-sectional shape in its relaxed configuration, Second and third stent segments located on both sides of the first stent segment, the second and third stent segments having a circularly relaxed axial cross-sectional shape, A liquid-tight cover positioned on at least one of the outer or inner diameters of the first, second, and third stent segments, A stent comprising: a blood flow outlet channel that fluidly communicates with the space on the outer diameter of the first stent segment, and is configured to allow blood flow to pass through the blood flow outlet channel and exit the space axially.

2. The stent according to claim 1, wherein the blood flow outlet channel comprises a tube positioned on the outer diameter of the second stent segment.

3. The stent according to claim 2, wherein the tube is connected to a suction pump configured to draw blood through the tube.

4. The stent according to claim 3, wherein the suction pump is associated with a delivery system configured to be used to deploy the stent into a target vessel.

5. The stent according to claim 2, wherein the pipe has a one-way valve in its flow path.

6. The stent according to claim 2, wherein the axial inner end of the pipe is deflected radially inward toward the outer diameter of the first stent segment.

7. The stent according to any one of claims 1 to 6, wherein the blood flow outlet channel comprises a one-way valve configured to allow blood flow in a first axial direction through the one-way valve and to block blood flow in a second axial direction opposite to the first axial direction.

8. The stent according to claim 7, further comprising a flap configured to deflect the one-way valve so as to be spaced away from the axial center of the stent.

9. The stent according to claim 7, wherein the one-way valve completely surrounds the outer diameter of the second stent segment.

10. The stent according to any one of claims 1 to 6, wherein the blood flow outlet channel has an opening within the liquid-tight cover.

11. The stent according to claim 10, wherein the opening of the liquid-tight cover is located within a portion of the liquid-tight cover associated with the transition segment of the stent between the first stent segment and the second stent segment.

12. The stent according to any one of claims 1 to 6, further comprising an inflatable balloon disposed within the inner diameter of the first stent segment.

13. The stent according to claim 12, wherein the balloon has an axial blood flow channel.

14. A method for removing blood captured around a tent implant, wherein the method is Deploying a covered stent implant into a blood vessel, wherein the stent implant includes an inner non-circular stent segment. Expanding the first and second circular end segments of the stent implant to fluidly seal the first and second circular end segments with respect to the blood vessel, A method comprising removing trapped blood from the space between the outer diameter of the inner non-circular stent segment and the blood vessel.

15. The method according to claim 14, wherein the removal of the captured blood comprises aspirating the captured blood through a tube extending along the outer diameter of the first circular end segment.

16. The method according to claim 14 or 15, wherein the removal of the captured blood is performed by causing expansion of one or more short-axis walls of the inner non-circular stent segment, thereby draining the captured blood from the space.

17. The method according to claim 16, wherein the discharge of the captured blood includes pushing the captured blood through a tube extending along the outer diameter of the first circular end segment.

18. The method according to claim 17, wherein the pipe is provided with a one-way valve within the flow path of the pipe.

19. The method according to claim 16, wherein the discharge of the captured blood comprises pushing the captured blood through a one-way valve associated with the first circular end segment.

20. The method according to claim 16, wherein the discharge of the captured blood comprises inflating a balloon into the channel of the inner non-circular stent segment.

Images