Stent valve delivery system

Abstract

A delivery system for delivering a stent-valve may include an inner shaft including a distal tip, a stent-valve crimped onto the inner shaft, a distal sheath disposed over at least a lower portion of the stent-valve, and a proximal sheath disposed over at least an upper portion of the stent-valve. The distal sheath has a proximal free end with a beveled proximal edge that defines a short side and a long side of the distal sheath. The proximal sheath is actuatable independently of the distal sheath and is movable proximally to release the upper portion of the stent-valve. The distal sheath is movable distally to release the lower portion of the stent-valve. The beveled proximal edge releases a first side of the lower portion of the stent-valve before an opposite second side.

Description

Technical Field

[0001] The present disclosure relates to medical devices, and more particularly, to delivery systems for replacement heart valves, and methods for using such medical devices and systems.

Background Art

[0002] For example, a variety of medical devices for medical use, including medical devices utilized to replace heart valves, have been developed. Heart function can be significantly impaired if the heart valve is not functioning properly. If the heart valve cannot close properly, blood in the heart chamber may flow backward or leak backward through the valve.

[0003] Valve regurgitation can be treated by replacing or repairing an abnormal valve such as the aortic valve. Surgical valve replacement is one method for treating an abnormal valve, but this requires an invasive surgical opening into the chest cavity, as well as stopping the patient's heart and cardiopulmonary bypass. Minimally invasive treatment methods such as transcatheter aortic valve implantation (TAVI) or transcatheter aortic valve replacement (TAVR) generally involve the use of a delivery catheter that is delivered to the heart through an arterial access or other anatomical pathway to replace the abnormal valve with a transplantable artificial heart valve.

[0004] In some cases, embolization of the artificial heart valve occurs, which is often due to movement of the artificial valve during or immediately after expansion during deployment. Each of the known delivery systems and methods for implanting an artificial heart valve has specific advantages and disadvantages. There is always a need to provide alternative delivery systems, as well as alternative methods for manufacturing and using medical devices.

Summary of the Invention

[0005] The present disclosure provides alternatives for the design, materials, manufacturing methods, and use of medical devices. An exemplary delivery system configured to deliver a stent valve includes an inner shaft including a distal tip, a stent valve crimped onto the inner shaft and including an upper portion, a lower portion, and a valve, and a distal sheath disposed to cover at least the lower portion of the stent valve, the distal sheath having a distal end connected to the distal tip and a proximal free end having an inclined proximal edge defining a short side portion and a long side portion of the distal sheath, and a proximal sheath disposed to cover at least the upper portion of the stent valve, the proximal sheath being operable independently of the distal sheath and movable in a proximal direction to release the upper portion of the stent valve. The distal sheath is movable in a distal direction to release the lower portion of the stent valve, and the inclined proximal edge releases the first side portion of the lower portion of the stent valve before the opposite second side portion.

[0006] Instead of or in addition to the above embodiments, the inclined proximal edge on the distal sheath is inclined at an angle of 10 degrees to 70 degrees with respect to the transverse axis of the distal sheath. Instead of or in addition to any of the above embodiments, the inclined proximal edge has an angle of 10 degrees to 20 degrees.

[0007] Instead of or in addition to any of the above embodiments, the delivery system further comprises a marker indicating the position of the long side portion of the distal sheath. Instead of or in addition to any of the above embodiments, the marker is a radiopaque marker on the distal sheath along the long side portion.

[0008] Instead of or in addition to any of the above embodiments, the marker is a radiopaque marker on the lower portion of the stent valve. Instead of or in addition to any of the above embodiments, the lower portion of the stent valve includes a plurality of lower crowns, and the long side portion includes a proximal extension configured to cover 1 to 5 of the lower crowns while the remaining lower crowns are released.

[0009] Instead of, or in addition to, any of the above embodiments, the proximal sheath has a distal free end with an inclined distal edge, and when the proximal sheath is moved in the proximal direction, the inclined distal edge releases the first side portion of the upper portion of the stent valve before the opposite second side portion.

[0010] Instead of, or in addition to, any of the above embodiments, the upper portion of the stent valve includes a plurality of arches and a plurality of upper crowns, and the distal end of the proximal sheath extends over the plurality of arches and the plurality of upper crowns.

[0011] Instead of, or in addition to, any of the above embodiments, the distal sheath includes a polymeric sheath and a reinforcing coil, and the reinforcing coil extends from the distal end of the distal sheath to a position adjacent to the inclined proximal edge.

[0012] Instead of, or in addition to, any of the above embodiments, the distal sheath includes a braid disposed proximally of the reinforcing coil. An exemplary delivery system configured to deliver a stent valve includes an inner shaft including a distal tip, a stent valve crimped onto the inner shaft and including a plurality of upper crowns, a plurality of lower crowns, and a valve, and a distal sheath disposed over and constraining the lower crown, the distal sheath having a distal end connected to the distal tip and a proximal free end having an inclined proximal edge angled between 5 degrees and 70 degrees with respect to the transverse axis of the distal sheath, and a proximal sheath disposed over the upper crown of the stent valve, the proximal sheath being operable independently of the distal sheath and movable in the proximal direction to release the upper crown of the stent valve, the distal sheath being movable in the distal direction to release the lower crown of the stent valve, and the inclined proximal edge gradually releasing the lower crown from a first side portion to a second side portion of the stent valve.

[0013] Instead of, or in addition to, the above embodiments, the inclined proximal edge has an angle between 10 degrees and 20 degrees. Instead of, or in addition to, any of the above embodiments, the angled proximal edge of the distal sheath defines the long side and the opposing short side of the distal sheath, and the delivery system further comprises a marker indicating the position of the long side of the distal sheath.

[0014] Instead of, or in addition to, any of the above embodiments, the marker is a radiopaque marker on the distal sheath along the long side. Instead of, or in addition to, any of the above embodiments, the marker is a radiopaque marker over one of the lower crowns positioned under the long side of the distal sheath.

[0015] Instead of, or in addition to, any of the above embodiments, the long side includes a proximal extension configured to cover one to five of the lower crowns while the remaining lower crowns are released.

[0016] An exemplary method of delivering a stent valve includes inserting the distal tip of a stent valve delivery system through a patient's aorta and aortic valve, the delivery system including an inner shaft including the distal tip, a stent valve crimped onto the inner shaft and including an upper portion, a lower portion, and a valve, and a distal sheath disposed to cover at least the lower portion of the stent valve, the distal sheath having a distal end connected to the distal tip and a proximal free end having an angled proximal edge defining a short side and a long side, the distal sheath including a radiopaque marker on the long side, and a proximal sheath disposed to cover at least the upper portion of the stent valve. The method includes aligning the radiopaque marker along the outer curve of the aorta, releasing the upper portion of the stent valve by moving the proximal sheath in a proximal direction, and releasing the lower portion of the stent valve by moving the distal sheath in a distal direction, the angled proximal edge releasing the first side of the lower portion of the stent valve positioned on the inner curve of the aorta prior to the opposing second side.

[0017] Instead of or in addition to the above-described embodiment, the step of moving the distal sheath includes a first stage in which the distal sheath is moved distally to a first position where the first side of the lower portion of the stent valve is released while the second side of the lower portion of the stent valve remains constrained by the distal sheath, and a second stage in which the distal sheath is further moved distally until the entire lower portion of the stent valve is released from the distal sheath.

[0018] Instead of or in addition to any of the above-described embodiments, after the first stage, the first side of the lower portion of the stent valve can engage a desired portion of the patient's anatomical structure, and then the second stage is performed to fully release the stent valve.

[0019] The above summary of some embodiments, aspects, and / or examples is not intended to describe every embodiment or all implementations of the present disclosure. The following drawings and detailed description illustrate these embodiments more specifically.

Brief Description of the Drawings

[0020] The present disclosure can be more fully understood by considering the following detailed description of various embodiments in connection with the accompanying drawings.

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[0021] Aspects of the present disclosure can accept various changes and alternative forms, details of which are shown in the drawings by way of example and described in detail. However, it should be understood that the intention is not to limit the aspects of the present disclosure to the specific embodiments described. In contrast, the intention is directed to all changes, equivalents, and alternatives falling within the technical idea and scope of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0022] Unless different definitions are given in the claims or other parts of this specification, the terms defined below shall apply. Whether or not explicitly indicated, all numerical values are assumed to be modified in this specification by the term "about." In the context of numerical values, the term "about" generally indicates a range of numbers that a person skilled in the art would consider equivalent to the recited value (e.g., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant digit. Other uses of the term "about" (e.g., in contexts other than numerical values) may be understood from the context of this specification and may be assumed to have their ordinary customary definitions consistent with the context of this specification, unless otherwise indicated.

[0023] The recitation of numerical ranges by endpoints includes all numbers within that range including the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Although some preferred dimensions, ranges, and / or values for various components, features, and / or specifications are disclosed, those skilled in the art will appreciate that desired dimensions, ranges, and / or values may deviate from those explicitly disclosed.

[0024] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of "and / or" unless the context clearly dictates otherwise. It should be noted that for ease of understanding, certain features of the present disclosure may be described in the singular, even though those features may be plural or repeated within the disclosed embodiment(s). Each instance of a feature includes and / or may be encompassed by a singular disclosure, unless the contrary is explicitly stated. For brevity and clarity, not all elements of the present disclosure are necessarily shown in each drawing or discussed in detail below. However, it will be understood that the following discussion may be equally applicable to any and / or all of two or more components, unless the contrary is explicitly stated. Further, for clarity, not all instances of some elements or features are shown in each drawing.

[0025] Relative terms such as "proximal", "distal", "advancing", "retracting", and variations thereof may generally be considered with respect to the positioning, orientation, and / or movement of various elements relative to the user / operator / manipulator of the device, where "proximal" and "retracting" indicate or refer to being closer to or towards the user, and "distal" and "advancing" indicate or refer to being further from or away from the user. In some cases, the terms "proximal" and "distal" may be arbitrarily assigned for ease of understanding of the present disclosure, in which case it will be readily apparent to those skilled in the art. Other relative terms such as "upstream", "downstream", "inflow", and "outflow" indicate the direction of fluid flow within a lumen such as a body lumen, blood vessel, etc., or within a device.

[0026] The term "range" may be understood to mean the maximum measured value of a dimension described or identified, unless the dimension of the problem or dimension is preceded by "minimum" or identified as "minimum", and "minimum" may be understood to mean the minimum measured value of a dimension described or identified. For example, "outer range" may be understood to mean the maximum outer dimension, "radial range" may be understood to mean the maximum radial dimension, "longitudinal range" may be understood to mean the maximum longitudinal dimension, and so on. Each example of "range" may be different (e.g., axial, longitudinal, transverse, radial, circumferential, etc.) and will be apparent to those skilled in the art from the context of the individual usage. Generally, "range" may be considered the largest dimension possible as measured according to the intended use, while "minimum range" may be considered the smallest dimension possible as measured according to the intended use. In some cases, "range" may generally be measured orthogonally within a plane and / or cross-section, but is not limited to this and may be measured differently, such as angularly, radially, circumferentially (e.g., along an arc), etc., as is apparent from the particular context.

[0027] The terms "monolithic" and "unitary" generally refer to one or more elements made of or consisting of a single structure or basic unit / element. Monolithic and / or unitary elements are intended to exclude structures and / or features made by assembling or otherwise joining together a plurality of separate elements.

[0028] References to "an embodiment", "some embodiments", "other embodiments", etc. in this specification indicate that the described embodiments may include certain features, structures, or characteristics, but not all embodiments necessarily include the certain features, structures, or characteristics. Further, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in relation to an embodiment, unless explicitly stated to the contrary or clearly stated otherwise, it would be within the knowledge of those skilled in the art to affect the particular feature, structure, or characteristic in relation to other embodiments. That is, the various individual elements described below can be combined or arranged with each other to form other additional embodiments or to complement and / or reinforce the described embodiments, as would be understood by those skilled in the art, even if not explicitly shown in a particular combination.

[0029] For clarity, a particular identification numbering system (e.g., first, second, third, fourth, etc.) may be used throughout the description and / or claims to name and / or distinguish the various described and / or claimed features. It is to be understood that the numbering system is not intended to be limiting and is merely illustrative. In some embodiments, for the sake of brevity and clarity, changes and departures from the previously used numbering system may be made. That is, a feature identified as a "first" element may later be shown as a "second" element, a "third" element, etc., or may be completely omitted, and / or a different feature may be shown as the "first" element. The meaning and / or designation in each case will be apparent to those skilled in the art.

[0030] The following description should be read with reference to the drawings which are not necessarily to scale, and like elements in different drawings are numbered the same. The detailed description and drawings are intended to illustrate, not to limit, the present disclosure. Those skilled in the art will recognize that the various elements described and / or shown can be arranged in various combinations and configurations without departing from the scope of the present disclosure. The detailed description and drawings show exemplary embodiments of the present disclosure. However, for clarity and ease of understanding, not all features and / or elements may be shown in each drawing, but the features and / or elements can be understood to exist as relevant unless otherwise indicated.

[0031] FIG. 1 shows a prior art aortic replacement stent valve 100. The stent components of the stent valve 100 include an upper portion having a plurality of support arches 101 and a plurality of upper anchoring crowns 104, and a lower stent portion 103 that supports a replacement valve 102 for regulating blood flow between the left ventricle and the aorta. The arches 101 define a proximal (P) or upstream end, and the lower stent portion 103 defines a distal (D) or downstream end. The lower stent portion 103 also includes a plurality of lower crowns 105. The arches 101 and the lower stent portion 103 are self-expandable and act as a fixation structure within the native aortic valve annulus for the valve 102.

[0032] In some cases, embolization of the stent valve 100 may occur after deployment and may be related to movement of the stent valve 100 during expansion or immediately after expansion during deployment. Conventional delivery systems for delivering an artificial stent valve cannot change or affect the final stage of release of the stent valve when the distal sheath is moved from the distal end of the stent valve. The subsequent expansion of the stent valve to contact the surrounding anatomical structure occurs very rapidly and without operator control.

[0033] FIG. 2 shows a conventional stent-valve delivery system 50 in a transfemoral access method. The delivery system 50 passes through the femoral artery and the vasculature, crosses the aortic arch 5, and is inserted through the aortic valve 7. The delivery system 50 may include a proximal sheath 40 and a distal sheath 60 having a linear proximal edge 62 that constrains the stent valve 100. After the proximal sheath 40 is retracted to release the arch 101, the distal sheath 60 is moved distally away from the lower stent portion 103, allowing the stent valve to expand relative to the aortic valve 7.

[0034] In some cases, particularly in patients with a tight curvature of the aortic arch, when the distal sheath 60 is moved distally away from the lower stent portion 103, the tight curvature of the aortic arch can curve the entire distal region of the delivery system 50 to conform to the anatomical structure. The outer curve and the linear proximal edge of the distal sheath 60 allow some of the lower crowns 105 along the outer curve to be released prior to the lower crowns on the opposite side of the stent, as shown by arrow 11 in FIG. 3. This early asymmetric release of the lower crowns 105 on the outer curve of the delivery system can cause the stent to "jump" or shift when the stent fully expands, resulting in an undesirable deployment location and / or position relative to the aortic valve 7. Retracting the distal sheath 60 and releasing the lower crowns 105 using a conventional delivery system results in rapid expansion and placement of the stent valve without an opportunity to correct the position of the stent valve.

[0035] Delivery system 250 with strategic shaping of the distal sheath 260 may provide better control for the release of the lower portion of the stent valve 100 and movement during stent valve expansion. Referring to FIG. 4, delivery system 250 can include an inner shaft 210 coupled to a distal tip 215 and an intermediate shaft 212 disposed to cover the inner shaft 210. A stent holder (not shown) may be coupled to the intermediate shaft 212. The inner shaft 210 may define a guide wire lumen. The stent valve 100 may be crimped onto the intermediate shaft 212 proximal to the distal tip 215. The distal sheath 260 can have a distal end 262 coupled to the distal tip 215 and a proximal free end 264 having an inclined proximal edge 266 that defines a short side portion 261 and a long side portion 263 of the distal sheath 260. The distal sheath 260 may be disposed to cover at least the lower stent portion 103.

[0036] The inclined proximal edge 266 may be inclined at an angle of 10 degrees to 70 degrees with respect to the transverse axis of the distal sheath. In other embodiments, the angle may be 10 degrees to 20 degrees. A shallower angle, such as 10 degrees, can achieve simultaneous release of the lower crown 105 according to the angle of the anatomical structure. The pattern of distal release may be adjusted at a specific proximal edge angle. In some embodiments, it may be desirable for the distal sheath 260 to utilize an angle of 20 degrees or more to constrain at least a first portion or side of the lower stent portion 103 of the stent valve 100. In other embodiments, it may be desirable to utilize a shallower angle, such as 10 degrees, to symmetrically or simultaneously release the entire lower stent portion 103.

[0037] By using a marker that indicates the position of the long side portion 263 of the distal sheath 260, it can help the user position the delivery system 250 for the desired deployment of the stent valve. As shown in FIG. 5, the marker can be a line 267 that extends partially or fully along the long side portion 263 of the distal sheath 260. The line 267 may be centered on the long side portion 263 such that the proximal end of the line 267 is at the proximal tip 265 of the inclined proximal edge portion 266. In other embodiments, the marker may be a dot 268 or other shaped marker that indicates the long side portion 263. The marker may generally be radiopaque so as to be visible by fluoroscopy, although other markers may be used according to the desired type of imaging used during deployment. Instead of, or in addition to, the marker on the distal sheath 260, a marker such as a radiopaque dot or line may be provided on the upper lower stent portion 103 of one of the lower crowns 105.

[0038] The proximal sheath 240 may be disposed to cover at least the upper portion of the stent valve 100. In some embodiments, the proximal sheath 240 may be disposed to cover the arch 101 and the upper fixing crown 104. The proximal sheath 240 and the distal sheath 260 may contact at the proximal tip 265 of the inclined proximal edge portion 266 of the distal sheath 260. In other embodiments, a gap may exist between the proximal tip 265 of the distal sheath 260 and the distal edge portion 244 of the proximal sheath 240. As shown in FIG. 4, the proximal sheath 240 may be operable independently of the distal sheath 260 and may be movable proximally relative to the inner shaft 210 and the intermediate shaft 212 to release the upper portion of the stent valve including the arch 101 and the upper fixing crown 104. When the proximal sheath 240 is pulled proximally, the arch 101 and the upper fixing crown 104 can expand at least partially, but the lower stent portion 103 remains constrained by the distal sheath 260, preventing the stent valve from being fixed within the natural valve.

[0039] The distal sheath 260 may be movable distally to gradually and incrementally release the lower stent portion 103 of the stent valve, and the inclined proximal edge 266 releases the lower crown 105 on the first side of the lower stent portion 103 before the opposite second side. As shown in FIG. 6, the short side portion 261 of the distal sheath 260 releases the lower crown 105 while the long side portion 263 covers and constrains the lower crown 105 on the opposite side of the lower stent portion 103. When only a portion of the lower crown 105 is released, the section of the lower stent portion 103 may expand, and this partial expansion may enable the movement and positioning of the stent valve within the native valve to achieve the desired position. As shown in FIG. 7, when the stent valve 100 is disposed in the desired position, the distal sheath 260 may be completely withdrawn distally, allowing the long side portion 263 to expose the last portion of the lower crown 105, at which time the lower stent portion 103 expands completely.

[0040] In some embodiments, the distal sheath 260 can include a polymeric sheath in which a reinforcing coil 269 is embedded. FIG. 8 shows the distal sheath 260 with the outer portion of the polymeric sheath removed to expose the reinforcing coil 269. The reinforcing coil 269 may extend from its distal end to a position adjacent the inclined proximal edge 266. In other embodiments, the distal sheath 260 can include struts 280 disposed proximally of the reinforcing coil 269. The struts 280 may extend from the reinforcing coil 269 to the proximal tip 265 of the inclined proximal edge 266. Alternatively, instead of a reinforcing coil, the distal sheath 260 may include struts that extend along the entire length of the proximal sheath.

[0041] In some embodiments, the long side 363 of the distal sheath 360 can include a proximal extension 369 configured to cover a portion of the lower crown 105 and leave all remaining lower crowns unconstrained. As shown in FIG. 9, the proximal extension 369 can be a rounded protrusion that defines the proximal tip 365 of the long side 363 of the distal sheath 360. The proximal extension 369 can be located directly opposite the lowest point on the short side 361 of the distal sheath 360. The proximal extension 369 can be sized to cover and hold from 1 to 5 lower crowns 105. By strategically shaping the tip portion of the distal sheath 360, the final release can be delayed and the risk of valve movement during release reduced such that the lower stent portion 103 is expanded and the stent valve remains fixed to the delivery system until juxtaposed against the anatomical structure.

[0042] FIG. 10 illustrates an embodiment of a proximal sheath 440 having a distal free end with an angled distal edge 444. When the proximal sheath 440 is moved in the proximal direction, the angled distal edge 444 releases the first side of the upper portion of the stent valve 100 before the opposite second side. In the illustrated embodiment, the angled distal edge 444 is angled in a direction opposite to the angled proximal edge 266. With the delivery system inserted such that the long side 463 of the proximal sheath 440 follows the outer curve of the aorta, the angled distal edge 444 can allow one of the arches 101 along the inner curve (left coronary artery side) to be released before the remaining arches, depending on the angle of the angled distal edge 444 and the curvature of the anatomical structure, or all arches can be released simultaneously. Alternatively, the angled distal edge 444 can be angled in the same direction as the angled proximal edge 266 of the distal sheath 260. In this orientation, the arches along the outer curve can be released first. Strategic shaping of the distal end of the proximal sheath allows for good control of the release of the arches 101, which can improve the final placement of the self-expanding stent valve 100.

[0043] A delivery system according to any of the above embodiments may be used in a method of delivering a replacement stent valve. In some embodiments, the stent valve may be used to replace the aortic valve. A transfemoral approach may be used through which the delivery system 250 can be tracked over a guidewire 290 previously placed through the femoral artery and vascular system, across the aortic arch 5, and through the aortic valve 7. The delivery system 250 may be advanced over the guidewire 290 until the distal tip 215 extends into the left ventricle 8 through the aortic valve 7, as shown in FIG. 11. Radiopaque markers disposed along the long side 263 of the distal sheath 260 may be used to orient the distal shaft such that the long side 263 is aligned with the outer curve 3 of the aorta. With the delivery system positioned with the stent valve 100 adjacent to the aortic valve 7, the proximal sheath 240 may be retracted proximally. The distal sheath 260 remains in place to maintain the lower portion of the stent in a constrained state. As the proximal sheath 240 moves proximally, as shown in FIG. 11, a portion of the stent valve 100 is exposed along with the angled proximal edge 266 of the distal sheath 260.

[0044] As shown in FIG. 12, the proximal sheath 240 may be fully retracted from the stent valve, releasing the arch 101 and the upper fixed crown 104. The distal sheath 260 remains covering the lower stent portion 103, preventing it from expanding. At this point, the position of the stent valve 100 can be adjusted relative to the aortic valve 7. As shown in FIG. 13, in the first stage of deployment, the distal sheath 260 is then moved distally from the lower stent portion 103 to a first position where the inclined proximal edge 266 gradually releases the lower crown 105 from the short side portion 261 of the distal sheath 260 corresponding to the inner curve of the aorta. The lower crown 105 on the outer curve side remains constrained by the long side portion of the distal sheath 260. As shown in FIG. 14, when the distal sheath 260 is moved further distally, the released lower crown 105 on the inner curve can position the stent valve for the appropriate final placement by engaging the desired portion of the anatomical structure. By releasing the lower crown 105 on the inner curve, the same problem as the release of the lower crown on the outer curve described above with respect to FIG. 3 does not occur because the inner curve maintains some compression of the lower stent portion 103 and the inclined proximal edge 266 on the distal sheath 260 provides additional control over the deployment of the lower crown 105 on the outer curve. As shown in FIG. 15, in the second stage of deployment, further distal movement of the distal sheath 260 releases all of the lower crown 105, the stent valve fully expands, the arch 101 and the upper fixed crown 104 engage the vessel wall, and the lower stent portion 103 seats within the aortic valve 7.

[0045] In other embodiments, particularly when the angle with respect to the angled proximal edge 266 is shallower, for example, 10 degrees, the distal movement of the angled proximal edge 266 can cause the stent-valve deployment to occur in a single step by simultaneously releasing all of the lower crowns 105. This embodiment can achieve symmetric distal release of the stent valve because the shallow angle of the angled proximal edge 266 causes the entire lower stent portion 103 to be released simultaneously when curved to follow the anatomical curve of the aorta. In this embodiment, the deployment transitions from the configuration shown in FIG. 12 to the configuration shown in FIG. 15.

[0046] The various components of the delivery system 250 (and / or other systems or components disclosed herein) and the various materials that can be used for the various elements disclosed herein may include those commonly associated with medical devices. For simplicity, the following discussion refers to the delivery system 250 (and variations, systems, or components disclosed herein). However, this is not intended to limit the devices and methods described herein, and the discussion may be applicable to other elements, members, components, or devices disclosed herein.

[0047] In some embodiments, the delivery system 250 (and variations, systems, or components thereof disclosed herein) may be made of metal, metal alloy, ceramic, zirconia, polymer (some examples of which are disclosed below), metal-polymer composites, combinations thereof, etc., or other suitable materials. Some examples of suitable metals and alloys include stainless steels such as 444V, 444L, and 314LV stainless steels; mild steel; nickel-titanium alloys such as linear elastic and / or superelastic nitinol; cobalt-chromium alloys, titanium and its alloys, alumina, diamond-like carbon coating (DLC) or titanium nitride-coated metal, other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS:N06625 such as INCONEL® 625, UNS:N06022 such as HASTELLOY® C-22®, UNS:N10276 such as HASTELLOY® C276®, and other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC® 400, and NICORROS® 400), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R44035 such as MP35-N®), nickel-molybdenum alloys (e.g., UNS:N10665 such as HASTELLOY® ALLOY B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, and other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R44003 such as ELGILOY®, and PHYNOX®); platinum-reinforced stainless steel; titanium; platinum; palladium; gold; and combinations thereof, etc.; or any other suitable material.

[0048] As referred to herein, within the family of commercially available nickel-titanium or nitinol alloys, there is a category referred to as "linear elastic" or "non-superelastic", which may be chemically similar to conventional shape memory and superelastic types, but exhibit distinct useful mechanical properties. Linear elastic and / or non-superelastic nitinol can be distinguished from superelastic nitinol in that the linear elastic and / or non-superelastic nitinol does not exhibit a substantial "superelastic plateau" or "flag region" as shown by superelastic nitinol in its stress / strain curve. Instead, in linear elastic and / or non-superelastic nitinol, as the recoverable strain increases, the stress is substantially linear until plastic deformation begins, or in some cases is linear but not necessarily entirely linear, or at least increases in a more linear relationship than the superelastic plateau and / or flag region that can be seen in superelastic nitinol. Thus, for the purposes of the present disclosure, linear elastic and / or non-superelastic nitinol may also be referred to as "substantially" linear elastic and / or non-superelastic nitinol.

[0049] In some cases, linear elastic and / or non-superelastic nitinol can also be distinguished from superelastic nitinol in that the linear elastic and / or non-superelastic nitinol can accept up to about 2 to 5% strain while remaining substantially elastic (e.g., prior to plastic deformation), while superelastic nitinol can accept up to about 8% strain prior to plastic deformation. Both of these materials can be distinguished from other linear elastic materials, such as stainless steel, which can only accept up to about 0.2 to 0.44 percent strain prior to plastic deformation (which can also be distinguished based on its composition).

[0050] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy is an alloy that does not exhibit a martensite / austenite phase change detectable by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) over a wide temperature range. For example, in some embodiments, in the linear elastic and / or non-superelastic nickel-titanium alloy, there may be no martensite / austenite phase change detectable by DSC and DMTA analysis in the range of about -60 degrees Celsius (°C) to about 120 °C. Thus, the mechanical bending properties of such materials can generally be inert to the influence of temperature over this very wide temperature range. In some embodiments, the mechanical bending properties of the linear elastic and / or non-superelastic nickel-titanium alloy at ambient temperature or room temperature are substantially the same as the mechanical properties at body temperature, for example, in that they do not exhibit a superelastic plateau and / or flag region. For example, over a wide temperature range, the linear elastic and / or non-superelastic nickel-titanium alloy maintains its linear elastic and / or non-superelastic features and / or properties.

[0051] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may be nickel in the range of about 50 to about 60 weight percent, with the balance being substantially titanium. In some embodiments, the composition comprises nickel in the range of about 54 to about 57 weight percent. An example of a suitable nickel-titanium alloy is the FHP-NT alloy commercially available from Furukawa Techno-Material Co., Ltd. in Kanagawa Prefecture, Japan. Other suitable materials may include ULTANIUM (trademark) (available from Neo-Metrics) and GUM METAL (trademark) (available from Toyota). In some other embodiments, a superelastic alloy, such as superelastic nitinol, may be used to achieve the desired properties.

[0052] In at least some embodiments, some or all of the delivery system 250 (and variations, systems, or components thereof disclosed herein) may also be doped with a radiopaque material, made of a radiopaque material, or otherwise include a radiopaque material. A radiopaque material is understood to be a material that can generate a relatively bright image with a fluoroscopic screen or another imaging technique during a medical procedure. This relatively bright image is useful when a user is determining the position of the delivery system 250 (and variations, systems, or components thereof disclosed herein). Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials filled with radiopaque fillers, and the like. Additionally, other radiopaque marker bands may also be incorporated into the design of the delivery system 250 (and variations, systems, or components thereof disclosed herein) to achieve the same result.

[0053] In some embodiments, multiple portions of the delivery system 250 (and variations, systems, or components thereof disclosed herein) may be made of or may include a polymer or other suitable material. Some examples of suitable polymers are polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block ester, polyurethane (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether ester (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester copolymers (e.g., other polyester elastomers such as butylene / poly(alkylene ether) phthalate and / or HYTREL® available from DuPont), polyamide (e.g., DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamide, block polyamide / ether, polyether block amide (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex® high density polyethylene, Marlex® low density polyethylene, linear low density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (e.g., EMS AmericanGRILAMID® available from Grilon, perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomer, polyurethane silicone copolymer (e.g., Elast-Eon® from AorTech Biomaterials or ChronoSil® from AdvanSource Biomaterials), biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, and polymer / metal composites thereof, etc. may be included. In some embodiments, the sheath may be mixed with a liquid crystal polymer (LCP). For example, the mixture can contain up to about 6% LCP.

[0054] It should be understood that the present disclosure is merely exemplary in many aspects. Without departing from the scope of the present disclosure, changes can be made in detail, particularly with respect to shape, size, and arrangement of steps. This may include the use of any of the features of one exemplary embodiment used in other embodiments within a suitable range. The scope of the present disclosure is, of course, defined by the language in which the appended claims are expressed.

Claims

1. A delivery system configured to deliver a stent valve, the delivery system comprising: an inner shaft including a distal tip; the stent valve crimped onto the inner shaft and including an upper portion, a lower portion, and a valve; a distal sheath disposed to cover at least the lower portion of the stent valve, the distal sheath having a distal end connected to the distal tip and a proximal free end having an inclined proximal edge defining a short side portion and a long side portion of the distal sheath; a proximal sheath disposed to cover at least the upper portion of the stent valve; a marker indicating the position of the long side portion of the distal sheath; wherein the proximal sheath is operable independently of the distal sheath and is movable proximally to release the upper portion of the stent valve; and the distal sheath is movable distally to release the lower portion of the stent valve, and the inclined proximal edge releases a first side portion of the lower portion of the stent valve before a second opposite side portion.

2. The delivery system of claim 1, wherein the inclined proximal edge on the distal sheath is inclined at an angle of 10 degrees to 70 degrees with respect to the transverse axis of the distal sheath.

3. The delivery system of claim 2, wherein the inclined proximal edge has an angle of 10 degrees to 20 degrees.

4. The delivery system of claim 1, wherein the marker is a radiopaque marker on the distal sheath along the long side portion.

5. The delivery system of claim 1, wherein the marker is a radiopaque marker on the lower portion of the stent valve.

6. The delivery system according to any one of claims 1 to 5, wherein the lower portion of the stent valve includes a plurality of lower crowns, and the long side portion includes a proximal extension configured to cover 1 to 5 of the lower crowns while the remaining lower crowns are released.

7. The delivery system according to any one of claims 1 to 5, wherein the proximal sheath has a distal free end with an inclined distal edge, and when the proximal sheath is moved proximally, the inclined distal edge releases a first side portion of the upper portion of the stent valve before a second opposite side portion.

8. ​ The upper portion of the stent valve includes a plurality of arches and a plurality of upper crowns, and a distal end of the proximal sheath extends to cover the plurality of arches and the plurality of upper crowns. The delivery system according to any one of claims 1 to 5.

9. The distal sheath includes a polymeric sheath and a reinforcing coil, and the reinforcing coil extends from a distal end of the distal sheath to a position adjacent to the inclined proximal edge. The delivery system according to any one of claims 1 to 5.

10. The distal sheath includes a braid disposed proximal to the reinforcing coil. The delivery system according to claim 9.

11. A delivery system configured to deliver a stent valve, an inner shaft including a distal tip, a stent valve crimped onto the inner shaft and including a plurality of upper crowns, a plurality of lower crowns, and a valve, a distal sheath disposed to cover the lower crown and restraining the lower crown, the distal sheath having a distal end connected to the distal tip and a proximal free end having an inclined proximal edge angled 5 degrees to 70 degrees with respect to a transverse axis of the distal sheath, a proximal sheath disposed to cover the upper crown of the stent valve, the proximal sheath being operable independently of the distal sheath and movable proximally to release the upper crown of the stent valve, the distal sheath being movable distally to release the lower crown of the stent valve, and the inclined proximal edge gradually releasing the lower crown from a first side portion to a second side portion of the stent valve, the inclined proximal edge of the distal sheath defines a long side portion and an opposing short side portion of the distal sheath, and the delivery system further comprises a marker indicating a position of the long side portion of the distal sheath. The delivery system.

12. The inclined proximal edge has an angle of 10 degrees to 20 degrees. The delivery system according to claim 11.

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