Stent-valves for valve replacement and associated methods and systems for surgery
Stent-valves (e.g., single-stent-valves and double-stent-valves), associated methods and systems for their delivery via minimally-invasive surgery, and guide-wire compatible closure devices for sealing access orifices are provided.
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The present application claims the benefit of U.S. Provisional Patent Application Nos. 60/753,071, filed Dec. 22, 2005, 60/755,590, filed Dec. 29, 2005, and 60/843,181, filed Sep. 7, 2006, each of which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTIONEmbodiments of the present invention relate to stent-valves, associated methods and systems for their delivery via minimally-invasive surgery, and guide-wire compatible closure devices for sealing access orifices.
BACKGROUND OF THE INVENTIONConventional approaches for cardiac valve replacement require the cutting of a relatively large opening in the patient's sternum (“sternotomy”) or thoracic cavity (“thoracotomy”) in order to allow the surgeon to access the patient's heart. Additionally, these approaches require arrest of the patient's heart and a cardiopulmonary bypass (i.e., use of a heart-lung bypass machine to oxygenate and circulate the patient's blood). Despite their invasiveness, these surgical approaches may be reasonably safe for a first intervention. However, tissue adherences resulting from the first surgery may increase the risks (e.g., death) associated with subsequent valve replacement surgeries. See Akins et al., “Risk of Reoperative Valve Replacement for Failed Mitral and Aortic Bioprostheses”, Ann Thorac Surg 1998; 65:1545-52; and Weerasinghe et al., “First Redo Heart Valve Replacement—A 10-Year Analysis”, Circulation 1999; 99:655-658; each of which is incorporated by reference herein in its entirety.
Synthetic valves and biological valves have been used for cardiac valve replacement with varying results. Synthetic valves rarely fail but require life-long anti-coagulant treatment to prevent blood from clotting (thrombosis) in and around the replacement valve. Such anti-coagulant treatment significantly limits patients' activities and can cause various other complications. Biological valves do not require such anti-coagulation treatment but typically fail within 10-15 years. Thus, to limit the need for and risks associated with re-operation on failed biological valves, traditionally only patients with less than about 10-15 years to live have received biological valve replacements. Patients with longer life expectancies have received synthetic valves and anti-coagulant treatment.
Attempts have been made to develop less-invasive surgical methods for cardiac valve replacement. These surgical methods, referred to as percutaneous heart valve replacement therapies (PHVT), use a catheter to deliver a replacement valve to an implantation site using the patient's vascular system. These PHVT attempts have various shortcomings, including their inability to ensure proper positioning and stability of the replacement valve within the patient's body.
Conventional closure devices for closing access orifices are also lacking in several respects, including the looseness of their fit which can cause bleeding after surgery. These closure devices also lack a central lumen, which renders them incompatible with guide wire delivery systems. One such conventional closure device is described in Malgorzata Pawelec-Wojtalik, “Closure of left ventricle perforation with the use of muscular VSD occluder”, European Journal of Cardio-Thoracic Surgery 27 (2005) 714-716, which is incorporated by reference herein in its entirety.
In view of the foregoing, it would be desirable to provide improved methods, systems, and devices for cardiac valve replacement.
SUMMARY OF THE INVENTIONSome embodiments of the present invention are directed to systems, methods, and devices for cardiac valve replacement. For example, these methods, systems, and devices may be applicable to the full range of cardiac-valve therapies including the replacement of failed aortic, mitral, tricuspid, and pulmonary valves. In some embodiments, the present invention may facilitate a surgical approach whereby surgery is performed on a beating heart without the need for an open-chest cavity and heart-lung bypass. This minimally-invasive surgical approach may reduce the risks associated with replacing a failed native valve in the first instance, as well as the risks associated with secondary or subsequent surgeries to replace failed artificial (e.g., biological or synthetic) valves.
Stent-valves according to some embodiments of the present invention may include a valve component and at least one stent component. The valve component may include a biological or synthetic (e.g., mechanical) valve and/or any other suitable material(s). The stent component may include a first section (e.g., proximal section), a second section configured to house the valve component, and a third section (e.g., distal section). The stent and valve components may be capable of at least two configurations: a collapsed configuration (e.g., during delivery) and an expanded configuration (e.g., after implantation).
In some embodiments, the first section of the stent valve may include a fixation element. Such a fixation element may include, for example, an annular groove for securing the stent-valve in place at an implantation site. When the stent-valve includes a single stent (“single-stent-valve”), the annular groove may be configured to receive the annulus of the valve in need of replacement. When the stent-valve includes two stents (“double-stent-valve”), the annular groove of the first stent component may be configured for matable attachment to a complimentary annular projection of a second stent component (i.e., a positioning stent). In turn, the second stent component may be anchored at the implantation site, for example, to the valve in need of replacement and/or adjoining structures.
Alternatively or additionally, in some embodiments the third section of the stent component may include at least one attachment element. Each attachment element of the stent-valve may include, for example, a geometrical opening (e.g., circular or ovular), hook, or strap configured for removable attachment to a complimentary structure of a delivery device. In addition, each attachment element may correspond to all or a portion of a commissural post, to which a commissure between two valve leaflets may be attached. The attachment element(s) may allow the stent-valve to be partially expanded within a patient's body while the stent-valve remains attached to the delivery device. This may allow the stent-valve to be returned to a collapsed configuration and repositioned within the patient's body when it is determined that fully expanding the stent-valve would cause the stent-valve to be installed incorrectly. Alternatively or additionally, this may allow the stent-valve to be returned to the collapsed configuration and removed from the patient's body when it is determined that the stent-valve is not functioning properly (e.g., not permitting sufficient flow). In some embodiments, the stent-valve may include one attachment element. In other embodiments, the stent-valve may include at least two, three, six, or any other suitable number of attachment elements. In some embodiments, the fully-expanded stent diameter in the region of the attachment element(s) may be smaller than the diameter of the region that houses an associated valve. This may reduce the risk of injury to the patient's body (e.g., perforation of the aorta) from the attachment elements and/or make it easier to affix the attachment elements to the complimentary structure of the delivery device.
In some embodiments, the stent component of the stent-valve may include a lattice structure with a plurality of cells. The lattice structure may be formed from, for example, a shape-memory alloy such as nitinol or any other suitable material(s). The cells in the lattice structure may be most densely populated in the section of the stent component that includes the fixation element. This may provide added support to the fixation element and increase the stability of the stent-valve. In some embodiments, the lattice structure may form at least one elongate stem (e.g., commissural post) that extends distally along the stent component towards the at least one attachment element. The at least one stem may connect directly to the at least one attachment element. Alternatively, the lattice structure may form at least one supporting element for connecting the at least one stem to the at least one attachment element. In some embodiments, all of the cells in the lattice structure may be closed cells, which may facilitate recapture of the stent-valve from the partially-expanded configuration to the collapsed configuration.
Still other embodiments of the present invention are directed to a method for replacing a valve. A stent-valve is provided that includes a stent component with an annular groove, and the stent-valve is secured axially to an annulus of the valve in need of replacement. In some embodiments, providing a stent-valve may include suturing a valve component to the stent component. Alternatively or additionally, providing a stent-valve may include expanding a valve component within the stent component in order to form a friction fitting. In some embodiments, providing a stent-valve may include securing a valve component to the stent component with a hook-and-loop (e.g., VELCRO®) fastening system.
In other embodiments of the present invention, a method for replacing a valve is provided whereby a first stent component that includes an annular element is implanted such that at least a portion of the first stent component is housed within a valve in need of replacement. A stent-valve that includes a second stent component is positioned within the first stent component by matably attaching a complimentary annular element of the second stent component to the annular element of the first stent component.
In still other embodiments of the present invention, a stent-valve delivery system is provided. A first assembly is provided that includes an outer sheath and a guide wire tubing. The delivery system also includes a second assembly including a stent holder configured for removable attachment to at least one attachment element of a stent-valve. The stent-valve may be positioned over the guide wire of the first assembly. The first assembly and the second assembly may be configured for relative movement with respect to one another in order to transition from a closed position to an open position. In the closed position, the outer sheath may encompass the stent-valve still attached to the stent holder and thus constrain expansion of the stent-valve. In the open position, the outer sheath may not constrain expansion of the stent-valve and thus the stent-valve may detach from the stent holder and expand to a fully expanded configuration.
In some embodiments, the first assembly and the second assembly may be configured to transition from the closed position, to a partially-open position, to the open position. In the partially-open position, the stent-valve may expand partially but not detach from the stent holder because the outer sheath may still encompass the at least one attachment element of the stent-valve and the stent holder. When the stent-valve is in the partially-expanded configuration, it may be determined whether the stent-valve will be positioned correctly if the stent-valve is expanded to the fully expanded configuration. Alternatively or additionally, the functionality of the stent-valve may be tested (e.g., to determine whether the stent-valve will permit sufficient blood-flow) when the stent-valve is in the partially-expanded configuration.
In some embodiments, the stent-valve delivery system may include at least one balloon (e.g., proximal to the stent-valve or other stent to be delivered) configured to cause expansion of the stent-valve or positioning stent upon inflation of the at least one balloon.
In some embodiments, the stent-valve delivery system may include a push handle that causes the relative movement of the first assembly and the second assembly. Alternatively, the stent-valve delivery system may include a screw mechanism for translating rotational movement of a handle into the relative movement of the first assembly and the second assembly.
In some embodiments, the stent-valve delivery system may include an integrated introducer within which the first assembly and the second assembly are positioned during delivery of the stent-valve to an implantation site. The integrated introducer may be configured to remain within a patient's body even after the first assembly and the second assembly are removed, for example, to allow for the introduction of an occluder.
In some embodiments, after expansion of the stent-valve to the fully expanded configuration, the delivery system may be configured to return to the closed position by passing the second assembly through the stent-valve towards a distal end of the first assembly.
Still other embodiments of the present invention are directed to a method for delivering a stent-valve to an implantation site whereby the stent-valve is removably attached to a delivery device and the stent-valve is delivered to the implantation site in a collapsed configuration. The stent-valve may be partially expanded while maintaining the stent-valve attached to the delivery device. A determination with respect to the stent-valve may be made when the stent-valve is in the partially-expanded configuration. When the determination yields a positive response, the stent-valve may be expanded to its fully expanded configuration by causing the stent-valve to detach from the delivery device.
In one particular embodiment, it may be determined whether the stent-valve is positioned correctly at the implantation site. The stent-valve may be returned to the collapsed configuration and repositioned when the stent-valve is not positioned correctly at the implantation site.
Alternatively or additionally, it may be determined whether a valve component of the stent-valve is functioning properly, for example, by testing whether the valve component will permit sufficient blood-flow. The stent-valve may be returned to the collapsed configuration and removed from a patient's body when the stent-valve is not functioning properly.
In some embodiments, delivering the stent-valve to the implantation site may include delivering the stent-valve to the heart for replacement of a cardiac valve. The delivery may include accessing a patient's body through an intercostal space (e.g., fifth intercostal space) and penetrating the left ventricle at the apex of the heart.
In still other embodiments of the present invention, an occluder for sealing an orifice in tissue is provided. The occluder may include a first portion capable of expansion from a collapsed configuration on a luminal side of the orifice to an expanded configuration. The occluder also includes a second portion capable of expansion from a collapsed configuration to an expanded configuration on a side of the orifice opposite to the luminal side. The first portion and the second portion may form a central, hollow channel for housing a guide wire.
In some embodiments, the occluder may include a connector for connecting the occluder to a catheter. For example, the connector may include a hollow screw mechanism for connecting to a threaded catheter. The occluder may be housed by a second catheter for delivery to the tissue orifice.
In some embodiments, the top portion of the occluder may include a channel sealing mechanism for preventing blood-flow from the luminal side of the tissue orifice. For example, the channel sealing mechanism may include a membrane, foam, and/or a valve. Suitable examples of foam and/or membranous materials include polyurethane and gelatin.
In some embodiments, the top portion of the occluder may include a first material and the bottom portion of the occluder may include a second material, where the second material may be coarser than the first material. This may facilitate the formation of scar tissue on the outer portion and speed the heeling process. For example, the first and/or second materials may include felt(s) and/or velour(s) made from Teflon, Dacron, polyurethane, polydioxanone, polyhydroxybutyrate, and/or other material.
In other embodiments of the present invention, a method for sealing an orifice in tissue is provided whereby an expandable and collapsible occlusion device is connected to a first catheter. The occlusion device may be inserted into a second catheter in a collapsed condition. The first catheter and a central channel of the occlusion device may receive a guide wire. The second catheter may be positioned in the orifice, such that a first end of the second catheter is positioned on a luminal side of the orifice. Relative-movement between the collapsed occlusion device and the second catheter may be caused in order to move the occlusion device out of the second catheter. Upon the occlusion device emerging from the first end of the second catheter, a first portion of the occlusion device may expand on the luminal side of the orifice. Upon the occlusion device being completely emerged from the second catheter, a second portion of the occlusion device may expand.
BRIEF DESCRIPTION OF THE DRAWINGSFor a better understanding of the present invention, reference is made to the following description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
FIGS. 17/18, 19, and 20 show additional examples of double-stent-valves according to some embodiments of the present invention;
FIGS. 21B-E show views of a double-conical stent in accordance with some embodiments of the present invention;
FIGS. 28A-C illustrate the replacement of a failed valve through the use of a delivery system according to some embodiments of the present invention;
Double-stent-valve 400 may be delivered to the implantation site using any suitable delivery approach. In some embodiments of the present invention, device 400 may be substantially entirely assembled from components 100, 200, and 300 outside the patient's body before device 400 is delivered to the implantation site. In other embodiments of the present invention, components 100, 200 and 300 of device 400 may be delivered to the implantation site separately in multiple steps. For example, stent component 300 may be delivered and installed at the implantation site, followed by the delivery and installation of stent component 200 and valve component 100 in one or more separate steps. In one embodiment, components 100 and 200 may be assembled outside the patient's body and then delivered and installed within component 300 at the same time. In another embodiment, stent component 200 may be delivered and installed within stent component 300, followed by the delivery and installation of valve component 100 in a separate step. Additional embodiments of double-stent-valves are described in connection with
In some embodiments of the present invention, a single-stent-valve (
In some embodiments of the present invention, valve component 100 may be flexible and collapsible such that it can be collapsed, for example, during delivery via a catheter to the implantation site. Various embodiments of delivery systems and surgical approaches for minimally-invasive surgery are described below in connection with
Valve component 100 may include a biological material (e.g., tanned, untanned, heterologous or autologous), non-biological material, a synthetic material (e.g., polymer(s) such as polyurethane and/or silicon(es)), or a combination thereof. In some embodiments, valve component 100 may include preserved biological tissue such as, for example, human tissue (e.g., homografts, autografts of valve tissue) or animal tissue (heterograft or xenograft valve tissue). In some embodiments, valve component 100 may be a mechanical valve. For example, when valve component 100 is a biological valve, expansion of valve component 100 from a collapsed configuration to an expanded may require self-expansion of an affixed stent component 200. In contrast, a synthetic valve component 100 may be capable of self-expansion. Valve component 100 may have a shape/form (e.g., length, width, diameter, etc.) corresponding to that of the intended valve application (e.g., tricuspid, pulmonary, mitral or aortic). In
In some embodiments of the present invention, stent component 200, like valve component 100, may be capable of at least two configurations: a first, collapsed configuration (e.g., during delivery) and a second, expanded configuration (e.g., after installation).
Valve component 100 may be secured to stent component 200 via any suitable securing mechanism or combination of securing mechanisms. For example, in one embodiment, valve component 100 may be sutured with one or more stitches to stent component 200. In another embodiment, valve component 100 may be secured to stent component 200 by way of a friction fitting. For example, valve component 100 may have a fully-expanded diameter that is slightly larger than the expanded diameter of stent component 200 such that components 100 and 200 fit securely together upon expansion of component 100 within component 200. In yet another embodiment, a hook-and-loop type (e.g., VELCRO®) fastening system may be used to secure valve component 100 to stent component 200. For example, stent component 200 may include microscopic hooks and valve component 100 may include corresponding microscopic loops (or vice-versa). This hook-and-loop fastening system may include a micro-velour material, which has been used previously for surgical applications to improve tissue in-growth. Such a hook-and-loop fastening system may allow the position of valve component 100 to be fine-tuned relative to the position of stent component 200, for example, after components 100 and 200 have been implanted within a patient's body. The hooks/loops may also facilitate blood clotting and the formation of a seal at the interface between valve component 100 and stent component 200. To avoid premature clot formation (e.g., excessive clot formation before installation is complete), anti-coagulation monitoring and/or treatment may be provided to the patient. Reliable hook-and-loop connections may still be achieved in the presence of premature clot formation, although higher activation pressure (described below) may be required. A preliminary evaluation shows that reliable hook-and-loop connections can be formed in the presence of water, jelly, liquid soap, and/or coagulating proteins. In some embodiments, such a hook-and-loop fastening system may be used, alternatively or additionally, to secure stent component 200 to stent component 300 (e.g., with the microscopic hooks attached to an exterior surface of stent component 200 and the corresponding microscopic loops attached to an interior surface of stent component 300, or vice versa).
Any suitable mechanism or combination of mechanisms (e.g., direct or indirect exertion of mechanical compression) can be used to supply the activation pressure required to cause the micro-hooks to attach to the micro-loops. For example, in some embodiments, one or more balloons may be positioned adjacent to valve component 100 and/or stent component 200 (e.g., within valve component 100) and inflated temporarily to bring the micro-hooks into contact with the micro-loops. Such balloon(s) may placed within the valve component 100 and/or stent component 200 subsequent to delivery of the stent and/or valve to the implantation site. Alternatively, in some embodiments the balloon(s) can be mounted (e.g., removably mounted) within the valve component 100 and/or stent component 200 prior to delivery of the stent and/or valve to an implantation site (e.g., prior to loading the stent and/or valve into a delivery device). The use of such balloon(s) is not limited to embodiments in which the valve and stent are affixed to one another by way of hooks/loops. Rather, such balloon(s) may be used whenever it is necessary or desirable to use the balloon(s) to aid in the expansion and/or engagement at the implantation site of the stent and/or valve (e.g., when the valve is sutured to the stent). In some embodiments, a self-expanding valve component 100 may be provided that self-expands within stent component 200 in order to cause the micro-hooks to contact the micro-loops.
Stent component 300 may be secured in place at the implantation site using any suitable securing mechanism or combination of securing mechanisms. For example, in some embodiments, fixation element 302 may form a recess (e.g., exterior annular groove) for receiving at least a portion of the failed valve. In some embodiments, stent component 300 may have a diameter slightly larger than a diameter of the implantation site such that delivery and expansion of stent component 300 at the implantation site secures stent component 300 in place by way of a friction fitting. In some embodiments, stent component 300 may include one or more projections (e.g., spikes) or clasps for anchoring stent component 300 to the failed valve and/or adjacent structure(s) at the implantation site.
In some embodiments of the present invention, stent-valve 600 may be inserted into the interior of the failed valve in the direction of arrow 608 in
In some embodiments, each of attachment elements 808 may include an opening (e.g., circular or ovular) for removably attaching stent component 800 to a complimentary element (e.g., wire, strap or hook) of a delivery device. Attachment elements 808 may allow for partial expansion of the stent component (e.g., together with an integrated valve component and/or another stent component) within a patient's body while causing the stent component to remain attached to the delivery system. For example, sections 802 and 804 (e.g., and part of section 806) of stent component 800 may expand when stent component 800 is partially released from a shaft during delivery, whereas no change may be observed to the relative positions of attachment elements 808 still constrained by the shaft (e.g., see
FIGS. 17/18, 19 and 20 show additional examples of double-stent-valves in accordance with some embodiments of the present invention. Single-stent valve 1700 of
Now referring to
FIGS. 21B-E show views of a double-conical stent in accordance with some embodiments of the present invention. Referring to
With respect to the first assembly, inner shaft 2204 functions as a lumen for a guide wire. Tip 2202 is bonded at its distal end. As used herein, bonding refers to any suitable securing/fastening mechanism such as, for example, adhesive bonding using cyanoacrylate or UV-curing adhesives or thermal bonding/welding using heat energy to melt the components to be assembled. Outer sheath 2206 may be bonded to the proximal section of tip 2202 and may constrain the stent-valve (2212, 2214). Outer sheath 2206 may be perforated to allow device flushing via hold handle 2210. The proximal part of the first assembly may be reinforced with metal shaft 2208 and may end into the push handle with a luer connector for guide wire lumen flushing.
With respect to the second assembly, stent holder 2222 may be bonded distally on distal outer shaft 2216.
Delivery system 2200 is said to be in an open position (
Delivery system 2200 is said to be in a partially open position when (for example) push handle 2210 is partially pushed towards hold handle cup 2228. In this partially open position, the stent-valve (2212, 2214) is deployed proximally and still attached distally to stent holder 2222 via the attachment elements. This allows for an accurate implantation/positioning of the stent-valve. For example, the stent-valve may be partially released proximal to the intended implantation site and slightly pushed distally until resistance is felt. Final release of the stent-valve (2212, 2214) may occur by completely pushing the push handle towards hold handle cup 2228 so that delivery system 2200 reaches the open position. Such a partially-open position is illustrated in
Upon implantation of the stent-valve (2212, 2214), delivery system 2200 may revert to the closed position prior to retrieval from the patient's body, for example, by holding the first assembly and pushing the second assembly distally towards tip 2202/outer sheath 2206. In other embodiments, the handle for releasing the stent-valve may comprise a screw mechanism for transferring a rotational movement of the handle into a translational movement of the outer sheath. This type of release system may allow for stepwise, more accurate stent release and recapturing as well as a reduction of the release force felt by the surgeon.
FIGS. 25A-C show another example of a delivery system 2500 in accordance with an embodiment of the present invention. Delivery system 2500 may include one or more balloons 2536 distal to the stent-valve. Having the balloon(s) distal to the stent-valve avoids having to introduce the delivery system deeper into the body (e.g., into the ascending aorta) in order to perform dilation, thereby reducing risk of injury to the body and improving device handling (e.g., no bending of rigid device over the aortic arch). Balloon(s) 2536 can be used for, for example, valvuloplasty prior to stent-valve implantation and/or post-dilation of the implanted stent-valve to improve the anchoring of the stent.
The first assembly of delivery system 2500 may include tip 2502, inner balloon shaft 2504, outer sheath 2506, and floating tube 2508. The second assembly may include inner shaft (distal) 2510, stent holder transition 2512, stent holder 2514, sleeve 2516, tapered transition shaft connector 2518, and outer shaft (proximal) 2520. The handle assembly may include hold handle connector 2522, hold handle cup 2524, O-ring 2526, metal shaft 2528, and push handle 2530. The balloon assembly may include outer shaft 2532, inner shaft 2534, balloon 2536, and Y connector 2538.
FIGS. 26A-C show another example of a delivery system 2600 in accordance with an embodiment of the present invention. Delivery system 2600 may include an integrated introducer 2602, which may be an additional assembly that houses the second assembly. The outer sheath of the delivery system is shown as 2604. Introducer 2602 may include a connecting line 2606, a stopcock 2608 and a housing 2610 for the sealing membrane 2612. Stopcock 2608 may serve as an access point for, for example, a syringe containing fluid (e.g., saline). Connecting line 2606 may serve to transport the fluid from the syringe to the inner lumen of the introducer, and sealing membrane 2612 may seal the introducer from the outside environment. Upon stent-valve implantation, the components of delivery system 2600 (e.g., first assembly and second assembly) other than introducer 2602 may be retrieved through the introducer. Then, another medical device such as, for example, a closure device may be introduced through introducer 2602. Examples of closure devices are described below in connection with
At stage 2704, the stent-valve may be delivered to an implantation site in a collapsed configuration. For example,
At stage 2706, the stent-valve may be partially expanded, for example, to determine (stage 2708) whether the stent-valve is in fact positioned correctly and/or to test (stage 2710) whether the stent-valve is functioning properly. For example,
At stage 2712, when the stent-valve is positioned correctly at the implantation site and/or the stent-valve is functioning properly, the stent-valve may be detached from the delivery system in order to cause the stent-valve to expand to its fully-expanded configuration. For example,
When the stent-valve is not positioned correctly (stage 2708), at stage 2714 the stent-valve may be reverted to the collapsed configuration and repositioned within the patient's body. An illustration of this scenario is illustrated in
Top portion 2902 of occluder 2900 may be positioned on the luminal side of an access orifice, while bottom portion 2904 may be positioned outside the access orifice. Guide wire compatibility may be achieved through a central channel within occluder 2900. The central channel may include at its bottom end, for example, a hollow screw device 2906 for attaching occluder 2900 to a catheter during delivery and detaching the occluder from the catheter upon installation within the access orifice. In other embodiments, occluder 2900 may be attached/detached to a catheter by a thin wall that can be twisted off, by a connection mechanism in the shape of a hook, or by a mechanism that detaches via galvanic corrosion or the like.
Occluder 2900 may include a channel sealing mechanism 2908 such as, for example, a self-sealing membrane and/or foam. In some embodiments, channel sealing mechanism 2908 may include a valve (e.g., one or more plastic leaflets). Channel sealing mechanism 2908 may prevent blood-flow through the occluder from top/luminal portion 2902 to bottom portion 2904 after the occluder is installed within the access orifice. During delivery, the positioning of a guide wire through channel sealing mechanism 2908 (and the central channel) may or may not substantially or entirely prevent blood-flow through channel sealing mechanism 2908. In some embodiments, mechanism 2908 may rely, at least in part, on blood clotting in order to form a seal. In some embodiments, mechanism 2908 (including a membrane, an iris mechanism, or collapsible walls) may form the seal (with or without assistance from blood clotting).
In some embodiments, top/luminal portion 2902 of occluder 2900 may be made from different material(s) (or the same material(s) but having different characteristics) than the material(s) used for bottom/outer portion 2904. For example, bottom/outer portion 2904 made be made from a coarser or more porous material than top/luminal portion 2902 to facilitate the formation of scar tissue on the outer portion. Bioabsorbable material(s) may also be used for portion 2902 and/or 2904 of occluder 2900 (e.g., magnesium and/or polydioxanone for a skeleton portion and/or polydioxanone, polyhydroxybutyrate, and/or gelatin as a filler).
Thus it is seen that stent-valves (e.g., single-stent-valves and double-stent-valves) and associated methods and systems for surgery are provided. Although particular embodiments have been disclosed herein in detail, this has been done by way of example for purposes of illustration only, and is not intended to be limiting with respect to the scope of the appended claims, which follow. In particular, it is contemplated by the inventors that various substitutions, alterations, and modifications may be made without departing from the spirit and scope of the invention as defined by the claims. Other aspects, advantages, and modifications are considered to be within the scope of the following claims. The claims presented are representative of the inventions disclosed herein. Other, unclaimed inventions are also contemplated. The inventors reserve the right to pursue such inventions in later claims.
Claims
1. A replacement valve for use within a human body comprising:
- a valve component; and
- a stent component comprising a first section, a second section for housing the valve component, and a third section,
- wherein the first section comprises an annular groove.
2. The replacement valve of claim 1, wherein the annular groove is configured to receive and secure circumferentially to an annulus of the valve in need of replacement.
3. The replacement valve of claim 1, further comprising a second stent component comprising an annular projection, wherein the annular projection is configured for matable attachment to the annular groove when the stent component is positioned within the second stent component.
4. The replacement valve of claim 1, wherein the valve component comprises a biological valve.
5. The replacement valve of claim 1, wherein the valve component comprises a synthetic valve.
6. The replacement valve of claim 1, wherein the stent component is self-expandable.
7. The replacement valve of claim 1, wherein the second section of the stent component follows a contour of the valve component.
8. The replacement valve of claim 1, wherein the stent component comprises a lattice structure comprising a plurality of cells, wherein the cells are most densely populated in the first section of the stent-valve.
9. The replacement valve of claim 8, wherein substantially all of the cells of the stent component are closed cells.
10. The replacement valve of claim 1, wherein the annular groove is formed from a plurality of independently bendable elements, wherein each bendable element comprises a bending deformation the location of which is determined by the lengths of an attached pair of struts.
11. The replacement valve of claim 1, wherein the second region comprises at least one locking element protruding outwardly from an outer surface of the second region.
12. The replacement valve of claim 11, wherein the second region comprises a plurality of locking elements that protrude outwardly from the outer surface of the second region and wherein at least two of the plurality of locking elements are positioned at different positions along a central axis of the stent component.
13. A replacement valve for use within a human body comprising:
- a valve component;
- a stent component comprising a first section, a second section for housing the valve component, and a third section,
- wherein the third section comprises at least one attachment element configured for removable attachment to a delivery device.
14. The replacement valve of claim 13, wherein the at least one attachment element comprises a geometric opening configured for removable attachment to a complimentary element of the delivery device.
15. The replacement valve of claim 13, wherein the at least one attachment element comprises a wire, hook, or strap configured for removable attachment to a complimentary element of the delivery device.
16. The replacement valve of claim 13, wherein the at least one attachment element comprises at least two attachment elements.
17. The replacement valve of claim 13, wherein the at least one attachment element comprises at least three attachment elements.
18. The replacement valve of claim 13, wherein the at least one attachment element comprises at least six attachment elements.
19. The replacement valve of claim 13, wherein the stent component comprises a lattice structure comprising:
- at least one commissural post; and
- the at least one attachment element.
20. The replacement valve of claim 19, wherein the lattice structure further comprises at least one supporting element for connecting the at least one commissural post to the at least one attachment element.
21. The replacement valve of claim 13, wherein the at least one attachment element projects at least partially inwardly toward a center axis of the stent component.
22. The replacement valve of claim 13, wherein the third section has a diameter that is less than a diameter of the second section.
23. A replacement valve for use within a human body comprising:
- a valve component; and
- a stent component comprising: a first section comprising a fixation element; a second section configured to house the valve component; and a third section comprising at least one attachment element.
24. The replacement valve of claim 23, wherein the fixation element comprises an annular groove.
25. The replacement valve of claim 24, wherein the annular groove is formed from a plurality of independently bendable elements, wherein each bendable element comprises a bending deformation the location of which is determined by the lengths of an attached pair of struts.
26. The replacement valve of claim 23, wherein the attachment element comprises a wire that forms an opening, hook, or strap.
27. The replacement valve of claim 23, wherein the second region comprises at least one locking element protruding outwardly from an outer surface of the second region.
28. A replacement valve for use within a human body comprising:
- a valve component; and
- at least two stent components affixed to one another comprising: a first section comprising a first cone or crown and a second stent structure collectively forming a fixation element; and a second section configured to house the valve component.
29. The replacement valve of claim 28, wherein the second stent structure comprises a cone or a crown.
30. The replacement valve of claim 28, wherein the second stent structure comprises a plurality of locking elements protruding outwardly from an outer surface of the first section and wherein at least two of the plurality of locking elements are positioned at different vertical positions along a central axis of the first section.
31. The replacement valve of claim 28, wherein:
- the at least two stent components further comprise a third section comprising at least one attachment element for removable attachment to a delivery device; and
- at least one of the first cone or crown and the second cone or crown has cross-section substantially in the shape of a pyramid.
32. A method for replacing a failed cardiac valve comprising:
- providing a stent-valve comprising a valve component and a stent component, wherein the stent component comprises an annular groove; and
- securing the annular groove axially to an annulus of the valve.
33. The method of claim 32, wherein providing a stent-valve comprises suturing the valve component to the stent component.
34. The method of claim 32, wherein providing a stent-valve comprises expanding the valve component within the stent component in order to form a friction fitting.
35. The method of claim 32, wherein providing a stent-valve comprises securing the valve component to the stent component with a hook-and-loop fastening system.
36. A method for replacing a worn or diseased cardiac valve comprising:
- implanting a first stent component comprising an annular element, wherein at least a portion of the stent component is housed within the worn or diseased valve; and
- positioning a stent-valve comprising a second stent component and a valve component within the first stent component, wherein the second stent component comprises a complimentary annular element for matably attaching to the first stent component.
37. A cardiac stent-valve delivery system comprising:
- a first assembly comprising an outer sheath and a guide wire tubing; and
- a second assembly comprising a stent holder configured for removable attachment to at least one attachment element of a stent-valve, the stent-valve positioned over the guide wire tubing of the first assembly,
- wherein the first assembly and the second assembly are configured for relative movement with respect to one another in order to transition from a closed position to an open position, such that in the closed position the outer sheath encompasses the stent-valve still attached to the stent holder and thus constrains expansion of the stent-valve, and such that in the open position the outer sheath does not constrain expansion of the stent-valve and thus the stent-valve detaches from the stent holder and expands to a fully expanded configuration.
38. The stent-valve delivery system of claim 37, wherein the first assembly and the second assembly are configured to transition from the closed position, to a partially-open position, to the open position, wherein in the partially-open position, the stent-valve expands partially proximally but does not detach from the stent holder because the outer sheath still encompasses the at least one attachment element of the stent-valve and the stent holder.
39. The stent-valve delivery system of claim 38, further comprising a flush mechanism.
40. The stent-valve delivery system of claim 37, further comprising at least one balloon configured to cause at least one of valvuloplasty prior to implantation of the stent-valve and expansion or post-dilation of the stent-valve upon inflation of the at least one balloon.
41. The stent-valve delivery system of claim 40, wherein the at least one balloon is housed proximally to the stent-valve.
42. The stent-valve delivery system of claim 40, wherein the at least one balloon is housed distally to the stent-valve.
43. The stent-valve delivery system of claim 40, wherein the at least one balloon is housed at least partially within the stent valve.
44. The stent-valve delivery system of claim 37, further comprising a push handle for causing the relative movement of the first assembly and the second assembly.
45. The stent-valve delivery system of claim 37, further comprising a screw mechanism for translating rotational movement of a handle into the relative movement of the first assembly and the second assembly.
46. The stent-valve delivery system of claim 37, further comprising an integrated introducer within which the first assembly and the second assembly are positioned during delivery of the stent-valve to an implantation site, wherein the integrated introducer is configured to remain within a patient's body even after the first assembly and the second assembly are removed.
47. The stent-valve delivery system of claim 37, wherein after expansion of the stent-valve to the fully expanded configuration, the delivery system is configured to return to the closed position by passing the second assembly through the stent-valve towards a distal end of the first assembly.
48. The stent-valve delivery system of claim 37, wherein the at least one attachment element of the stent-valve comprises a geometrical opening configured for removable attachment to a complimentary structure of the stent holder.
49. The stent-valve delivery system of claim 48, wherein the geometrical opening comprises a circular or ovular opening.
50. The stent-valve delivery system of claim 37, wherein the at least one attachment element of the stent-valve comprises a wire, hook, or strap configured for removable attachment to a complimentary structure of the stent holder.
51. The stent-valve delivery system of claim 37, wherein the at least one attachment element of the stent-valve comprises at least two attachment elements configured for removable attachment to corresponding number of complimentary structures of the stent holder.
52. The stent-valve delivery system of claim 37, wherein the at least one attachment element of the stent-valve comprises at least three attachment elements configured for removable attachment to corresponding number of complimentary structures of the stent holder.
53. The stent-valve delivery system of claim 37, wherein the at least one attachment element of the stent-valve comprises at least six attachment elements configured for removable attachment to corresponding number of complimentary structures of the stent holder.
54. The stent-valve delivery system of claim 37, wherein the stent-valve comprises a lattice structure comprising:
- at least one commissural post; and
- the at least one attachment element.
55. The stent-valve delivery system of claim 54, wherein the lattice structure of the stent-valve further comprises at least one supporting element for connecting the at least one commissural post to the at least one attachment element.
56. A method for delivering a cardiac stent-valve to an implantation site comprising:
- removably attaching the stent-valve to a delivery device;
- delivering the stent-valve to the implantation site in a collapsed configuration;
- partially proximally expanding the stent-valve while maintaining the stent-valve attached to the delivery device; and
- making a determination with respect to the stent-valve when the stent-valve is in the partially-expanded configuration.
57. The method of claim 56, wherein the making a determination comprises determining whether the stent-valve is positioned correctly at the implantation site.
58. The method of claim 57, further comprising returning the stent-valve to the collapsed configuration and repositioning the stent-valve when the stent-valve is not positioned correctly at the implantation site.
59. The method of claim 56, wherein the making a determination comprises determining whether a valve component of the stent-valve is functioning properly.
60. The method of claim 59, wherein determining whether the valve component is functioning properly comprises testing whether the valve component will permit sufficient blood-flow.
61. The method of claim 59, further comprising returning the stent-valve to the collapsed configuration and removing the stent-valve from a patient's body when the stent-valve is not functioning properly.
62. The method of claim 56, further comprising causing the stent-valve to fully expand by causing the stent-valve to detach from the delivery device, when the making a determination yields a positive response.
63. The method of claim 56, wherein the delivering the stent-valve to the implantation site comprises delivering the stent-valve to the heart for replacement of a cardiac valve, wherein the delivering further comprises:
- accessing a patient's body through an intercostal space; and
- penetrating the left ventricle at the apex of the heart.
64. The method of claim 63, wherein the accessing comprises accessing the patient's body through a fifth intercostal space.
65. An occluder for sealing an orifice in tissue comprising:
- a first portion capable of expansion from a collapsed configuration on a luminal side of the orifice to an expanded configuration; and
- a second portion capable of expansion from a collapsed configuration to an expanded configuration on a side of the orifice opposite to the luminal side,
- wherein said first portion and said second portion form a central, hollow channel for housing a guide wire.
66. The occluder of claim 65, further comprising a connector for connecting the occluder to a catheter.
67. The occluder of claim 66, wherein the connector comprises a hollow screw mechanism for connecting the catheter to a threaded catheter.
68. The occluder of claim 66, further comprising a second catheter for housing the occluder for delivery to the tissue orifice.
69. The occluder of claim 65, wherein the first portion of the occluder further comprises a channel sealing mechanism for preventing blood-flow from the luminal side of the tissue orifice.
70. The occluder of claim 69, wherein the channel sealing mechanism comprises at least one of a membrane and foam.
71. The occluder of claim 69, wherein the channel sealing mechanism comprises a valve.
72. The occluder of claim 65, wherein the top portion of the occluder comprises a first material and the bottom portion of the occluder comprises a second material, wherein the second material is coarser than the first material.
73. A method for sealing an orifice in tissue, comprising:
- connecting an expandable and collapsible occlusion device to a first catheter, the occlusion device comprising (i) a first portion capable of expansion from a collapsed configuration to an expanded configuration and a second portion capable of expansion from a collapsed configuration to an expanded configuration, (ii) a central channel for housing a guide wire, and (iii) a connector for connecting the occluder device to the first catheter;
- inserting the occlusion device into a second catheter in a collapsed condition;
- receiving, by the first catheter and central channel, a guide wire;
- positioning the second catheter in the orifice, such that a first end of the second catheter is positioned on a luminal side of the orifice; and
- causing relative movement between the collapsed occlusion device and the second catheter to move the occlusion device out of the second catheter, wherein upon the occlusion device emerging from the first end of the second catheter, the first portion of the occlusion device expands on the luminal side of the orifice and wherein upon the occlusion device being completely emerged from the second catheter, the second portion expands.
74. The method of claim 73, wherein the tissue orifice comprises a tissue orifice in the left ventricle of the heart, and the positioning the second catheter in the tissue orifice comprises delivering the second catheter to the left ventricle via an intercostal space.
Type: Application
Filed: Dec 21, 2006
Publication Date: Sep 13, 2007
Applicant: SYMETIS SA (Lausanne)
Inventors: Ludwig Von Segesser (Lausanne), Stephane Delaloye (Bulach)
Application Number: 11/700,922
International Classification: A61F 2/24 (20060101);