Stent loading device with fluid reservoir

Abstract

A device and method for predictably and controlling the contraction of a contractible and expandable stent for subsequent translation through a delivery sheath lumen to an anatomical target (such as a heart valve or intravascular location) for expansion and implantation. A loading device is defined in an inner cavity, the inner cavity including an inner diameter that continuously decreases from a proximal to a distal direction, the inner diameter alternating between a decreasing diameter and a constant diameter until the inner diameter of the delivery sheath is reached. A fluid-filled reservoir is provided at the proximal end of the loading device, the reservoir being configured to provide moisture or wetting to a material associated with or attached to the stent that requires moisture retention. Thus, when the stent is contracted within the loading device, at least a portion of the stent can be immersed in the fluid reservoir to retain the subject material.

Description

[0001] Inventor

[0002] Alex A. Peterson, Maple Grove, MN, U.S. citizen

[0003] Jason S. Diedering, Minneapolis, MN, U.S. citizen

[0004] Saravana B. Kumar, Minnetonka, MN, U.S. citizen

[0005] CROSS-REFERENCE TO RELATED APPLICATIONS

[0006] This application claims priority to U.S. non-provisional patent application No. 16 / 558,897, filed on September 3, 2019, and entitled “STENT LOADING DEVICE WITH FLUID RESERVOIR,” and also claims the benefit of U.S. provisional application serial number 62 / 726,614, filed on September 4, 2018, and entitled “STENT LOADING DEVICE WITH FLUID RESERVOIR,” the entire contents of which are incorporated herein by reference.

[0007] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0008] not applicable Background Art Technical Field

[0009] The present invention relates to devices and methods for implanting devices within heart chambers. More specifically, the present invention relates to devices configured to load a stent (e.g., a prosthetic heart valve frame) into the lumen of a delivery sheath or catheter for translation through the lumen to the distal end of the delivery sheath or catheter.

[0010] Description of the Prior Art

[0011] Stents in a broad sense, and more specifically, prosthetic heart valves and left atrial appendage occlusion devices are well known in the art. Native heart valves (e.g., aortic, pulmonary, tricuspid and mitral valves) are essential for ensuring only forward flow of adequate blood supply through the cardiovascular system. These heart valves may lose function, especially due to congenital, inflammatory, infectious diseases or conditions. Early interventions repaired or replaced dysfunctional valves during open heart surgery. Recently, in addition to the open heart surgery methods discussed above, access to the valve of interest can also be achieved percutaneously via at least one of the following known access routes: transapical delivery technology; transfemoral delivery technology; transatrial delivery technology; and transseptal delivery technology, collectively referred to as transcatheter technology.

[0012] Typically, in transcatheter technology, a prosthetic valve is mounted in a stented frame that is capable of achieving a collapsed state and an expanded state. The device is collapsed and advanced through a sheath or delivery catheter positioned in the patient's blood vessel until it reaches the implantation site. The stented frame is typically released from the catheter or sheath and expanded in the heart with the valve to an expanded functional size and orientation by various means. One of the key issues is the ease of delivery of the prosthetic valve (including the stent frame and valve). More specifically, the outer diameter of the contraction device within the catheter is of great concern. The present invention solves this problem.

[0013] Description of Related Technology

[0014] The human heart consists of four chambers and four heart valves that facilitate the forward (antegrade) flow of blood through the heart. The chambers include the left atrium, left ventricle, right atrium, and right ventricle. The four heart valves include the mitral valve, tricuspid valve, aortic valve, and pulmonary valve. See generally Figure 1 .

[0015] The mitral valve is located between the left atrium and the left ventricle, and helps control the flow of blood from the left atrium to the left ventricle by acting as a one-way valve to prevent backflow into the left atrium. Similarly, the tricuspid valve is located between the right atrium and the right ventricle, while the aortic valve and the pulmonary valve are semilunar valves located in the arteries that allow blood to flow away from the heart. The valves are all one-way valves, with leaflets that open to allow forward (antegrade) blood flow. Normally functioning valve leaflets close under the pressure exerted by the reverse blood to prevent blood from flowing back (retrograde) into the chamber where the blood has just flowed out. For example, the mitral valve provides a one-way valve between the left atrium and the left ventricle when it works normally, opening to allow antegrade flow from the left atrium to the left ventricle, and closing to prevent retrograde flow from the left ventricle into the left atrium. This retrograde flow (when present) is called mitral valve regurgitation or mitral valve regurgitation.

[0016] Native heart valves may malfunction or become malfunctioning due to a variety of reasons and / or conditions, including but not limited to disease, trauma, congenital malformations, and aging. These types of conditions may result in the valve structure not being able to close properly, resulting in retrograde blood flow from the left ventricle to the left atrium in the event of mitral valve failure.

[0017] Mitral regurgitation is a specific problem caused by a dysfunctional mitral valve that allows at least some retrograde blood flow from the right atrium back into the left atrium. In some cases, the dysfunction is caused by mitral valve leaflets that prolapse upward into the left atrial chamber (i.e., above the upper surface of the annulus, rather than connecting or fitting to prevent retrograde flow). This backflow of blood places a strain on the left ventricle, with a volume load that can result in a series of compensatory left ventricular adaptations and adjustments (including remodeling of the ventricular chamber size and shape) that vary widely over the long-term clinical course of mitral regurgitation.

[0018] Regurgitation may often be a problem with native heart valves, including the tricuspid, aortic, and pulmonary valves, as well as the mitral valve.

[0019] Therefore, native heart valves (e.g., mitral valves) may often require functional repair and / or assistance (including partial or complete replacement). Such interventions can take several forms, including open heart surgery and open heart implantation of replacement heart valves. See, e.g., U.S. Pat. No. 4,106,129 (Carpentier) for highly invasive procedures fraught with patient risk, requiring not only prolonged hospitalization but also a very painful recovery period.

[0020] Minimally invasive methods and devices for replacing dysfunctional heart valves are also known, and relate to percutaneous access and catheter-assisted delivery of replacement valves. Most of these solutions involve replacement heart valves attached to structural supports (such as stents known in the art), or other forms of wire networks designed to expand when released from a delivery catheter. See, for example, U.S. Patent No. 3,657,744 (Ersek); U.S. Patent No. 5,411,552 (Andersen). Self-expanding variants of support stents help position the valve and keep the expanded device in the proper position in the subject's heart chamber or blood vessel. This self-expanding form also has problems when the device is not correctly positioned in the first positioning attempt (which is usually the case), and therefore must be recaptured and repositioned. In the case of a fully or even partially expanded device, this recapture process requires the device to be retracted to a position that allows the operator to retract the retracted device into the delivery sheath or catheter, adjust the inlet position of the device, and then re-expand to the proper position by redeploying the position-adjusted device to the delivery sheath or catheter distal end. Deflation of an already expanded device is difficult because the expanded stent or wire network is typically designed to achieve an expanded state that also resists contraction or retraction forces.

[0021] In addition to the open heart surgical approaches discussed above, access to the valve of interest is achieved percutaneously via at least one of the following known access routes: transapical delivery techniques; transfemoral delivery techniques; transatrial delivery techniques; and transseptal delivery techniques.

[0022] In general, the art focuses on systems and methods that allow for partial delivery of a collapsed valve device utilizing one of the above-described known access routes, wherein one end of the device is released from a delivery sheath or catheter and expanded for initial positioning, and then fully released and expanded when proper positioning is achieved. See, e.g., U.S. Pat. Nos. 8,852,271 (Murray, III), 8,747,459 (Nguyen), 8,814,931 (Wang), 9,402,720 (Richter), 8,986,372 (Murray, III), and 9,277,991 (Salahieh); and U.S. Patent Publications Nos. 2015 / 0272731 (Racchini) and 2016 / 0235531 (Ciobanu).

[0023] In addition, known "replacement" prosthetic heart valves are intended to completely replace native heart valves. Therefore, these replacement heart valves physically engage tissue and / or valve leaflets within the annular throat (i.e., below the annular plane and the upper annular surface), thereby eliminating all remaining functions of the native valve and making the patient completely dependent on the replacement valve. In general, maintaining and / or retaining the native function of the heart valve is a preferred solution, so it is preferred to supplement the valve rather than completely replace it. Obviously, in some cases, the native valve almost completely loses function before the interventional implantation surgery, or the native valve continues to lose function after the implantation surgery. The preferred solution is to deliver and implant a valve device that can be used as an additional and / or supplementary functional valve, and is fully capable of replacing the native function of a valve that has lost or is about to lose most or all of its function. However, unless otherwise stated, the inventive solution described below will generally apply to all types and forms of heart valve devices. As those skilled in the art will recognize, the present disclosure is also generally applicable to stents.

[0024] Furthermore, known solutions for, e.g., mitral valve replacement systems, devices, and methods require a dual chamber solution, i.e., the implanted replacement valve device engages and engages in both the left atrium and the left ventricle. Typically, these solutions include a radially expanded stent in the left atrium with anchors or tethers (set downward through the native annulus or annular throat) connected from the stent device downward through the annular throat, with a sub-annular surface located within the left ventricle, the left ventricular fascia, or even into the left ventricular wall surface. See, e.g., the AVD-1000 sold by Abbott Laboratories. Currently the only approved prosthetic device in the United States. When The catheter is inserted into the femoral vein. The device is passed into the heart through the inferior vena cava, into the right atrium and across the septum. It enters the left ventricle through the annulus and lies beneath the leaflets, clamping them to reduce regurgitation.

[0025] Such dual chamber and native annulus solutions are unnecessarily bulky, thus making delivery and positioning / recapture / repositioning more difficult from a strictly structural standpoint. Furthermore, dual chamber solutions present difficulties in making the ventricular anchoring and / or tethering connections required to maintain position. Moreover, these solutions interfere with native valve function as described above, since the portion of the device disposed within the left ventricle must pass through the native annulus and / or annular throat and the native mitral valve, thereby destroying any remaining coaptation ability of the native leaflets. Additionally, dual chamber solutions typically require invasive anchoring of some native tissue, resulting in unnecessary trauma and potential complications.

[0026] It will also be appreciated that bi-chamber mitral valve solutions require sub-annular and / or ventricular engagement with anchors, tethers, etc., precisely because the atrial portion of the device cannot adequately anchor itself to the atrial chamber and / or the upper portion of the annulus. Again, unless otherwise noted, some embodiments described herein, or portions thereof, may be readily applied to single or dual chamber solutions.

[0027] Finally, known prosthetic heart valves are composed of two or three leaflets, which are arranged to be used as one-way valves, allowing fluid to flow through in the anterograde direction while preventing retrograde flow. The native mitral valve is located at the fourth cartilage behind the sternum and is composed of anterior leaflet, posterior leaflet, chordae tendineae, papillary muscles, ventricular wall and valve ring connected to the atrium. Each native leaflet is supported by chordae tendineae, which are attached to the papillary muscles, which are tightened with each ventricular contraction to maintain valve function. The anterior leaflet and posterior leaflet of the native valve are attached to both the anterior lateral papillary muscles and the posterior medial papillary muscles via primary, secondary and tertiary chordae tendineae. In the case of myocardial injury, the destruction of any papillary muscle can lead to dysfunction of the anterior leaflet or posterior leaflet of the mitral valve. Other mechanisms may cause one or two failures of the native mitral leaflets. If a single mitral leaflet fails, regurgitation can be returned to the left atrium in the form of a non-central, eccentric blood jet. Other leaflet failures can include more concentrated regurgitation jets. Known prosthetic valve replacements typically include leaflets that are arranged to mimic native valve structure, which, over time, can become susceptible to similar regurgitant outcomes.

[0028] Applications of collapsible and expandable stents are not limited to prosthetic heart valve implants. Vascular stents are commonly used and are usually collapsible to facilitate delivery through the lumen of a delivery catheter to a work site where the stent is translated out of the lumen of the catheter and expanded by a self-expanding device or by an expansion mechanism (such as, inter alia, an expandable balloon).

[0029] As discussed above, known delivery methods and devices include expandable prosthetic valve stents and vascular stents that shrink during delivery via a delivery catheter. The problem with this contraction and expansion structure includes applying strain on the area of ​​the structure (e.g., stent) that must be bent to adapt to the contracted state and the expanded state. In addition, the geometry of the contraction in the known device may be uncontrolled or unpredictable, which increases the strain on the structural elements of contraction and expansion. Therefore, the structure and method for realizing the contracted state in the delivery catheter or sheath lumen must allow predictable and repeatable contraction to maintain and retain the integrity of the contraction structure. In addition, stents (e.g., prosthetic heart valves or vascular stents) may include biological and / or biocompatible materials that cannot be allowed to dry. Therefore, it is crucial to retain a fluid reservoir in which the subject's stent can reside.

[0030] Various embodiments of the present invention address these problems, among other things. Summary of the invention

[0031] A device and method for predictably and controlling the contraction of a contractible and expandable stent for subsequent translation through a delivery sheath lumen to an anatomical target (such as a heart valve or intravascular location) for expansion and implantation. A loading device is defined in an inner cavity, the inner cavity including an inner diameter that continuously decreases in a proximal to distal direction, the inner diameter alternating between a decreasing diameter and a constant diameter until the inner diameter of the delivery sheath is reached. A fluid-filled reservoir is provided at the proximal end of the loading device, the reservoir being configured to provide moisture or wetting to a material associated with or attached to the stent that requires moisture retention. Thus, as the stent is being contracted with the loading device, at least a portion of the stent can be immersed in the fluid reservoir to retain the subject material. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Certain features of the heart are shown in cross-section.

[0033] Figure 2 A perspective view of an exemplary bracket is shown.

[0034] Figure 3A Shows Figure 2 A bottom view of one embodiment of a transition section of an exemplary stent.

[0035] Figure 3B Shows Figure 2 A bottom view of one embodiment of a transition section of an exemplary stent.

[0036] Figure 3C Shows Figure 2 A bottom view of one embodiment of a transition section of an exemplary stent.

[0037] Figure 4A Shows Figure 2 A bottom view of one embodiment of a contracted transition section of an exemplary stent.

[0038] Figure 4B Shows Figure 2 A bottom view of one embodiment of a contracted transition section of an exemplary stent.

[0039] Figure 5 A side cross-sectional view of one embodiment of the present invention is shown.

[0040] Figure 6 A perspective view is shown of one embodiment of the present invention.

[0041] Figure 7A side cutaway view of one embodiment of the present invention is shown. DETAILED DESCRIPTION

[0042] In general, various embodiments of the present invention are directed to devices and methods for achieving a predictable collapsed configuration or state of a collapsible and expandable support structure or stent and providing a mechanism for ensuring moisture retention within a biomaterial that may be attached or otherwise integrated with the collapsible and expandable support structure during the collapsing step.

[0043] The support structure or stent has multiple functions to assist in the treatment of heart valve regurgitation (mitral or tricuspid). These functions include: its function as a scaffold to enable the 4C valve to work, juxtaposition with the atrial anatomy, optimized radial force to conform to ventricular expansion, the ability to load and deploy from a minimally invasive delivery system, and a geometry that supports the reduction of paravalvular leakage (PVL). The design features of the stent are suitable for meeting one or more of the functions noted above. The specific design features and attributes of the exemplary stent are discussed in detail below to help understand the practicality of the funnel loading device and related methods. As discussed above, the present invention is not limited to prosthetic heart valves that include a stent support structure, but can also be applied to retractable and expandable stents such as those commonly used in endovascular surgery.

[0044] The stent design concepts of certain exemplary embodiments are intended to support minimally invasive surgery for treating mitral, tricuspid and / or other valvular regurgitation. The stent can be self-expanding (e.g., nitinol or similar materials) or balloon expandable (e.g., cobalt chromium or similar materials). The stent is typically made of cells, which can be open-cell diamond-shaped structures or continuous structures with working unit elements. The stent can also be constructed using tubes, wires, braids or similar structures. Specific design features that contribute to the function of the stent are described in detail below.

[0045] Bracket "iris" transition unit

[0046] Now refer to Figures 2 to 3B One embodiment of the stent 100 of the present invention includes: an outer segment 102, which can be generally circular, although it is not necessarily a perfectly circular structure when fully and / or partially expanded; and an inner valve support segment 104, which can be cylindrical, but it is not necessarily a cylinder of constant diameter, and is suitable for supporting and retaining a prosthetic valve leaflet ( Figure 2), most preferably at a point located above a native annulus (e.g., a mitral valve annulus), although other attachment points for the prosthetic leaflet are within the scope of the invention. Additionally, as discussed above, stent 100 can be configured to supplement and / or replace the function of a tricuspid valve. A preferred construction includes a prosthetic leaflet disposed above a native leaflet, wherein the prosthetic leaflet is attached and sufficiently spaced from (above) the native leaflet so as not to physically interfere with or interact with the native leaflet. However, certain embodiments contemplate some interaction with the native leaflet.

[0047] The individual cells C forming the outer section 102 of the stent 100 O exist Figure 2 As can be seen in FIG. 1 , the open cell area is defined by the material used to form the expandable stent 100 .

[0048] The individual units C forming the inner valve support segment 104 I Also shown is an open area formed within the inner region R defined by the outer segment 102, wherein the inner valve support segment extends radially upward into the inner region R. As shown, each unit C I The size of each unit C O The sizes of each unit C are different. I Can include with each unit C O The shapes of different shapes.

[0049] The region of the stent 100 that facilitates the radially inward transition of the stent 100 from the outer section 102 to the inner section 104 of the stent 100 is a transition cell region 106. The transition cell region 106 may include cells C T , Unit C T Can include external segment unit C O and / or inner section unit C I Different sizes and / or shapes. The outer region 102 and / or the inner region 104 and / or the transition unit region 106 of the stent 100 can be constructed of a continuous structure, or two or more structures can be combined to achieve the desired design goals. The transition unit region 106 generally includes a radially upward bend to allow the inner valve support segment 104 to reside in the inner region 102, such as Figure 2 In some embodiments, the lower portion of the inner valve support segment 104 (ie, the cell C of the inner valve support segment 104 and the transition cell region 106) T The connected portion) may also include a curved shape to facilitate and / or complete the radial upward turn into the inner region 102.

[0050] Transition Unit C TThe geometry and / or shape of the Figure 3A ) may be a substantially straight segment, or as shown in Figure 3B As shown in FIG. 1 , an offset or twist may be included in the stent cell pattern to allow for controlled compression of the stent upon expansion. When viewed from the bottom of the stent 100, an exemplary cross-sectional geometry of the transition cell region 106 is shown in FIG. Figure 3A and Figure 3B Schematically presented in .

[0051] Such transitional cell regions 106 of the stent 100 may be struts, complete cell sections, or partial cell sections. The transitional cell regions 106 may have any number of struts (minimum 3) or cell sections generally required to meet design requirements. Figure 3A As shown in Figure 2, transition unit C T Or the struts can be evenly spaced and formed by substantially straight and equally spaced struts 108 extending away from the internal valve support segment 104, with the angles α on both sides of the struts 108 being equal, and the angles β on both sides of the struts 108 being equal relative to their intersection or integration with the external support segment 102.

[0052] In a preferred embodiment, the struts 108 of the transition section 106 may be as follows: Figure 3A is straight, but Figure 3C , with unequal angles relative to the inner valve support segment 104 and the outer support segment 102. Therein, the straight struts 108 are inclined so as to provide a smaller angle α and a larger angle α' relative to the inner valve support segment 104. Similarly, a smaller angle β' and a larger angle β are provided relative to the outer support segment 102. This allows for compressive nesting of the inclined struts 108 of the transition segment 106.

[0053] In another preferred embodiment, the transition cell region 106 may include transition cell struts 108', which include transition cells CT formed by struts 108' having offsets (i.e., non-straight), twists, and / or curves. The degree of offset and / or twist and / or curvature of the struts 108', and therefore the size and / or shape of the resulting expanded cells CT, may vary depending on the number of cells / struts in the transition cell region 106, the packing density when the stent is collapsed, and the stress / strain distribution constraints of the transition cell region 106.

[0054] For several reasons, Figure 3B and Figure 3C The structural ratio Figure 3A A straight transition unit region 106 structure is preferred. Figure 4A Shows the use of Figure 3AThe substantially straight struts 108 are formed into a transition unit region 106 in a constricted form with undesirable gaps G between selected struts 108. Although such a resulting transition unit region 106 with constricted gaps is feasible, it is not optimal.

[0055] Therefore, using e.g. Figure 3B The plurality of struts 108' may be offset and / or twisted and / or bent or Figure 3C The inclined straight pillar 108, Figure 4B The transition section 106 allows a controlled and predictable contraction pattern of the stent without gaps between the struts 108'. This in turn minimizes the amount of stress / strain concentration at the lower region of the stent 100 during contraction, which is required to deliver the expandable stent 100 to the heart region of interest. In addition, the contraction of the unit is also symmetrical and uniform, which helps to mitigate damage to the valve tissue or fabric when the valve tissue or fabric is attached to the stent unit. The reduction in the total stress / strain of the transition strut section can benefit the durability of the stent and valve tissue.

[0056] like Figure 3B , Figure 3C and Figure 4B Certain embodiments of the transition unit region 106, i.e., having offset, twisted and / or bent struts 108' or inclined straight struts 108, are characterized by, for example, Figure 3B As best shown in FIG. 1 , the struts 108' each include the same offset, twist, and / or curvature. This in turn enables close nesting of adjacent struts 108' as the stent 100 is collapsed for delivery and subsequently expanded.

[0057] Thus, the design of the transition section allows for controlled compression of the stent and reduces stress concentrations on the stent cells as the stent is collapsed for loading into a delivery system. The transition strut section can contribute to the durability of the stent and valve tissue.

[0058] As those skilled in the art will now appreciate from the above, the geometry of the struts of the exemplary stent enables transition from expansion to contraction.

[0059] Figure 5 and Figure 6 An exemplary loading device 200 is shown that can initiate the transition of an exemplary stent and other collapsible and expandable support structure stents from expansion to contraction, wherein the contracted state or configuration is prepared and sufficient for translation into and along a delivery catheter or sheath to a target anatomical location.

[0060] Thus, the stent loading device 200 includes a proximal transition section 201 that decreases in diameter from proximal to distal, the proximal transition section 201 being in fluid communication with a substantially cylindrical proximal end section 202 of constant diameter that transitions to a decreasing diameter section 204 that in turn transitions to a distal constant diameter section 206. The decreasing diameter section 204 is illustrated as being conical, but various embodiments may include a curved and / or concave profile. In each case, the dimensional requirement is that the inner diameter of the decreasing diameter section 204 provides a substantially smooth transition of decreasing diameter from the substantially cylindrical constant diameter section 202 to the distal constant diameter section 206 that in turn is operably attached to and in fluid communication with the proximal end of a delivery sheath 207, wherein the proximal end refers to the portion of the delivery sheath 207 that is located outside the patient's body. It will be readily appreciated that a lumen is defined within the loading device 200 having a diameter at the constant diameter section 206 that is substantially the same as the diameter of the lumen of the delivery sheath 207 , thereby providing a smooth transition therebetween as the contracted stent structure translates through the constant diameter section 206 into and through the lumen of the delivery sheath 207 .

[0061] The device 200 may include one or more of the segments to be mated together, or it may be manufactured as a single device, either embodiment of which may be fluidly coupled to the proximal end of the delivery sheath 207 .

[0062] In addition, a fluid reservoir 208 is provided to be operably connected and communicated with at least a portion of the proximal surface of the device. As shown, the fluid reservoir 208 comprises a curvilinear shape designed to hold and retain liquid during the process of loading the stent into the device, which will in turn maintain the integrity of any biological and / or biocompatible materials integrated with or attached to the stent.

[0063] Now explaining the structure of the loading device, those skilled in the art will recognize the practicality in achieving the transition of the stent from an expanded size to a predetermined contracted size having a predetermined diameter. Thus, the exemplary stent shown above can pass through the constant diameter cylindrical section 202 and slowly translate along the decreasing diameter section 204. As the stent advances, the inner wall of the cylindrical portion 202 and / or the decreasing diameter section 204 applies equal forces around the circumference of the stent, thereby enabling the stent to contract along the point of least resistance and least stress. As discussed above, the circular and / or spiral struts will enable a predetermined, predictable and repeatable contraction motion, resulting in a predetermined, predictable and repeatable contraction shape, which includes a diameter and / or contraction shape determined at least in part by the inner diameter of the distal constant diameter section 206. When the stent has been gradually contracted and finally reaches the distal constant diameter section 206, the contracted stent can be translated along it, or along a connected delivery sheath or catheter 207 having an inner diameter that is the same or similar to the distal constant diameter section 206 to the anatomical location of interest. When the contracted stent is released from the distal end of the constraining structure, it will be allowed to expand with a bias, effectively reversing the contraction motion to reach the expanded state or configuration.

[0064] Usually, if Figure 5 , Figure 6 and Figure 7 As shown in , the loading device 200 includes an inner lumen L defined by a varying inner diameter therethrough. Thus, moving in a proximal to distal direction, a proximal transition section 201 includes an inner diameter D1 at its proximal end, which is the maximum inner diameter of the device 200, and transitions to an inner diameter D2, which is less than D1, at the distal end of the proximal transition section 201. The distal end of the proximal transition section 201 is operably and fluidly engaged with a proximal end of a cylindrical section 202 of constant inner diameter D2, which is the same inner diameter D2 as the inner diameter D2 of the distal end of the proximal transition section 201. The distal end of the constant diameter section 202 is operably and fluidly engaged with a proximal end of a decreasing diameter section 204, which includes an inner diameter D2 at its proximal end, which is the same as the inner diameter D2 of the constant diameter cylindrical section. The decreasing diameter section 204 defines an inner diameter that decreases along its length from the proximal end to the distal end, at which the inner diameter is a minimum value D3 for the entire lumen L of the device 200. The distal constant diameter section 206 is fluidically and operably coupled to the distal end of the decreasing diameter section and includes the same inner diameter D3 as the distal end of the decreasing diameter section 204, which is the same inner diameter D3 as the lumen defined by the delivery sheath 207, to which the distal end of the distal constant diameter section is operably and fluidly coupled.

[0065] The loading device discussed above also makes it possible to include a stent of a biological or other material that must remain moist to retain the required moisture during loading. In addition, a stent including a biological or other material that must remain moist can be preloaded for future use. Therefore, the stent can be contracted and loaded into the inner chamber of the loading device together with the fluid captured by the fluid reservoir 208 to keep the biological and / or biocompatible materials appropriately moistened, thereby preparing for translation, delivery and implantation immediately after loading or later (i.e., preloading). The fluid reservoir 208 is shown as including an inner curved surface 209 and a lip 210 around the top 212 of the reservoir 208, and in some embodiments shown, a cup with an open top can be taken. The lip 210 can extend inwardly through a portion of the inner curved surface 209 to help retain the fluid and / or the contracted or partially contracted stent in the fluid reservoir 208. In practice, a biocompatible fluid may be added to the fluid reservoir 208 such that at least a portion of the shrinking and / or shrunken stent structure, for example, prosthetic valve leaflets and / or skirt material disposed on the outer and / or inner surfaces of the shrunken stent, may be disposed within the fluid.

[0066] In some embodiments, preloading may include collapsing the stent at least partially within the proximal transition section 201 and / or the constant diameter cylindrical section 202, and continuously wetting critical biological or biocompatible materials associated with the stent by immersion in the fluid within the fluid reservoir 208. In other cases, preloading may include collapsing the stent at least partially within the distal constant diameter section 206, and continuously wetting critical biological or biocompatible materials associated with the stent by immersion in the fluid reservoir 208.

[0067] The description of the present invention and its application set forth herein is illustrative and is not intended to limit the scope of the present invention. The features of each embodiment can be combined with other embodiments within the concept of the present invention. Modifications and modifications of the embodiments disclosed herein are possible, and those skilled in the art will understand the actual alternatives and equivalents of the various elements of the embodiments when studying this patent document. These and other modifications and modifications may be made to the embodiments disclosed herein without departing from the scope and spirit of the present invention.

Claims

1. A loading device for shrinking a stent in preparation for delivery and implantation in the body, the stent comprising a material requiring moisture retention, the loading device include: a fluid reservoir comprising a curved inner surface and operably connected to the proximal end of the loading device and in fluid communication with the inner cavity of the loading device; as well as a fluid, wherein the fluid reservoir is configured to be at least partially filled with the fluid; wherein the fluid reservoir is configured to hold and retain a fluid and has an open cup shape having an upper surface including a lip extending around the upper surface and partially extending inwardly over the curved inner surface of the fluid reservoir; and The lip is configured as follows: retaining a fluid within the fluid reservoir; and The collapsed stent is retained within the fluid reservoir.

2. The loading device according to claim 1, in, The fluid is biocompatible.

3. The loading device according to claim 1, in, The stent includes a prosthetic heart valve frame.

4. The loading device according to claim 2, in, The stent includes a prosthetic mitral valve frame.

5. The loading device according to claim 1, in, The stent includes an intravascular stent.

6. The loading device according to claim 2, in, The material requiring moisture retention comprises a prosthetic leaflet comprising a biological or biocompatible material, and wherein the prosthetic leaflet is immersed in the fluid reservoir.

7. The loading device according to claim 1, in, The lumen includes two regions of decreasing inner diameter moving from the proximal end of the lumen to the distal end of the lumen.

8. The loading device according to claim 6, in, The stent is adapted to be at least partially collapsed within the lumen of the loading device, and wherein the material requiring moisture retention is immersed in the fluid of the fluid reservoir.

9. The loading device according to claim 6, in, The lumen includes two sections of constant inner diameter.

10. The loading device according to claim 9, in, The two sections of constant inner diameter have different inner diameters.

11. The loading device according to claim 9, in, The distal-most region of constant inner diameter is the smallest inner diameter of the lumen of the loading device.

12. A loading device for a retractable stent, include: an inner lumen defined by the housing, wherein the inner lumen comprises a proximal end and a distal end, two inner diameter sections of decreasing diameter and two inner diameter sections of constant diameter, wherein the distal end of the inner lumen comprises a minimum inner diameter and the proximal end of the inner lumen comprises a maximum inner diameter; a fluid reservoir comprising a curved inner surface and operably connected to the proximal end of the loading device and in fluid communication with the inner cavity of the loading device; and a fluid, wherein the fluid reservoir is configured to be at least partially filled with the fluid; wherein the fluid reservoir is configured to hold and retain a fluid and has an open cup shape having an upper surface including a lip extending around the upper surface and partially extending inwardly over the curved inner surface of the fluid reservoir; and The lip is configured as follows: retaining a fluid within the fluid reservoir; and The collapsed stent is retained within the fluid reservoir.

13. A method of preloading a stent into a collapsed configuration in preparation for subsequent translation and implantation within an anatomical target, include: Providing a collapsible and expandable stent, the stent comprising a material that needs to be moisturized; A loading device is provided, the loading device comprising: a fluid reservoir comprising a curved inner surface and operably connected to the proximal end of the loading device and in fluid communication with the inner cavity of the loading device; and fluid; partially translating the collapsible and expandable stent into the lumen of the loading device to initiate controlled, predictable partial contraction of the stent within the lumen while ensuring that at least a portion of the collapsible and expandable stent is submerged in the fluid of the fluid reservoir to wet the material requiring moisture retention; and subsequently translating the partially collapsed stent further into the lumen of the loading device to achieve a predetermined collapsed shape and diameter for translation through the lumen of an operably connected delivery sheath for translation, delivery, and implantation into an anatomical target; in, The fluid reservoir is configured to be at least partially filled with a fluid and configured to hold and retain the fluid; The inner cavity of the loading device includes two sections with decreasing inner diameters in the direction from the proximal end to the distal end and two sections with constant inner diameters; The fluid reservoir has an open cup shape having an upper surface including a lip extending around the upper surface and partially extending inwardly over the curved inner surface of the fluid reservoir; and The lip is configured as follows: retaining a fluid within the fluid reservoir; and The collapsed stent is retained within the fluid reservoir.

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