Patent Application
20190091016
The present disclosure relates generally to devices, systems, and methods for use in the cardiac system, and more particularly, to a device, system, and method for native valve replacement and/or augmentation.
The circulatory system of mammals includes the heart and the interconnecting vessels throughout the body, including both veins and arteries. In particular, the human heart includes four chambers, the left and right atrium and the left and right ventricle. The mitral valve allows blood flow in one direction and is positioned between the left ventricle and the left atrium. Also, the tricuspid valve is positioned between the right ventricle and the right atrium, the aortic valve is positioned between the left ventricle and the aorta, and the pulmonary valve is positioned between the right ventricle and the pulmonary artery.
Each heart valve functions in concert to move blood throughout the circulatory system. As such, the right ventricle pumps oxygen-poor blood from the body to the lungs and then into the left atrium. From the left atrium, the blood is pumped into the left ventricle and then out through the aortic valve and into the aorta. The blood is then recirculated throughout the tissues and organs of the body and returns once again to the right atrium.
If the valves of the heart do not function properly, due either to disease or congenital defects, the circulation of the blood may be compromised. Diseased heart valves can be stenotic, where the valve does not open sufficiently to allow adequate forward flow of blood through the valve, and/or incompetent, where the valve does not close completely.
Incompetent heart valves can cause regurgitation or excessive backward flow of blood through the valve when the valve is closed. For example, certain diseases of the heart valves can result in dilation of the heart and one or more heart valves. When a heart valve annulus dilates, the valve leaflet geometry deforms and causes ineffective closure of the valve leaflets. The ineffective closure of the valve can cause regurgitation of the blood, accumulation of blood in the heart, and other problems.
Embodiments of the present disclosure are directed to a device, system, and method for percutaneous heart valve replacement. For example, the device can include a prosthetic heart valve that can be used to replace an incompetent valve (e.g., an aortic valve or a pulmonary valve) in a body lumen. Embodiments of the prosthetic valve include a valve frame, a valve leaflet coupled to the valve frame, and a stent anchoring frame coupled to the valve frame.
The prosthetic heart valve of the present disclosure can allow for the repositioning and/or removal of the prosthetic heart valve during the percutaneous delivery of the prosthetic heart valve to a treatment site. In addition, the prosthetic heart valve of the present disclosure is designed to prevent migration of the prosthetic heart valve once it is deployed in a body lumen. Since the prosthetic heart valve is for heart valve replacement, the design requirements can vary as compared to, for example, a venous valve. For example, the prosthetic heart valve is designed to withstand in situ pressures of more than thirteen thousand three hundred thirty (13,330) Pascal (100 torr) in the forward flow direction, and nearly thirty-three thousand three hundred thirty (33,330) Pascal (250 torr) in the reverse flow direction. In contrast, a prosthetic venous valve can be designed to withstand, for example, in situ pressure across a prosthetic venous valve that is approximately two thousand six hundred seventy (2,670) Pascal (20 torr). In addition, the prosthetic heart valve is also designed to accommodate mechanical forces and movements which are imposed by the tissues to which they are attached without damage and without migration or misalignment.
As such, the prosthetic heart valve of the present disclosure includes an expandable valve frame coupled to an expandable stent anchoring frame, and at least one valve leaflet coupled to the valve frame. As discussed herein, by coupling the valve frame to the stent anchoring frame, the valve frame can be positioned at a treatment site and the stent anchoring frame can prevent migration of the valve frame.
The valve frame includes valve frame members and the stent anchoring frame includes stent frame members defining a first portion and a second portion of the stent anchoring frame. The second portion of the stent anchoring frame has greater flexibility than the first portion. In addition, the first portion of the stent anchoring frame and the valve frame define a length, where the stent frame members and the valve frame members along the length provide a contiguous surface over which a delivery device can repeatedly slide over the length in its entirety in two longitudinal directions. Also, the delivery device can slide repeatedly over the length when the first portion and the valve frame are in a partially expanded state during delivery from the delivery device.
The configuration of the first portion forms a contiguous surface that allows for the repositioning and removal of the prosthetic heart valve if the valve frame is not in the desired position. For example, once the prosthetic heart valve is at a delivery site, the valve frame can be at least partially deployed, allowing the function of the valve frame and valve leaflets to be observed. If the valve frame is not in a satisfactory position, a sheath is able to advance over the contiguous surface of the first portion of the stent anchoring frame and the valve frame, compressing the valve frame to allow for the repositioning of the prosthetic heart valve.
The figures herein follow a numbering convention in which the first digit or digits correspond to the drawing figure number and the remaining digits identify an element or component in the drawing. Similar elements or components between different figures may be identified by the use of similar digits. For example, 110 may reference element “10” in
Various embodiments of the present disclosure are illustrated in the figures. Generally, the prosthetic heart valve can be implanted within the fluid passageway of a body lumen, for example, for replacement or augmentation of a valve structure within the body lumen (e.g., an aortic valve), to regulate the flow of a bodily fluid through the body lumen in a single direction.
The embodiments of the prosthetic heart valve of the present disclosure include a valve frame and a stent anchoring frame that self-expand. The valve frame and/or stent anchoring frame can self-expand to a fully deployed state and/or a semi-deployed state depending on what portions of the valve frame and/or stent anchoring frame are restrained by elements of a delivery device (e.g., sheaths). In some instances, the position of the prosthetic heart valve relative to the desired implant location can be adjusted to correct changes or misalignments of the heart valve that can occur during delivery. In addition, restraining portions of the valve frame and/or stent anchoring frame prior to completing the deployment can allow for adjustments due to movement caused by the flow output from the ventricle pushing on the deployment system, which can be the case when implanting, for example, an aortic valve.
As used herein, a semi-deployed state of the valve frame and/or stent anchoring frame lies between an undeployed state (i.e., the state of the valve frame and stent anchoring frame at the time the prosthetic valve is outside the body and in a delivery device) and a deployed state (i.e., the state of the valve frame and stent anchoring frame at the time the prosthetic valve is to be left in the body).
In the various embodiments, holding the valve frame in the deployed state while the stent anchoring frame is in the undeployed state allows the prosthetic heart valve to be positioned in a desired location prior to its final deployment. This staged deployment of the prosthetic heart valve of the present disclosure is in contrast to prosthetic heart valves that are deployed without the advantage of temporarily pausing at an intermediate deployment stage (i.e., the partial deployment state) to allow for adjustments in the placement of prosthetic heart valve prior to full deployment.
In addition, the size of the prosthetic valve 100 can be varied in accordance with whether the prosthetic valve 100 is to be used to replace the aortic valve or the pulmonary valve, or when the prosthetic valve 100 is to be used as a supplementary valve to be positioned in the vasculature. These dimensions (e.g., 20-30 millimeters (mm)) can be readily determined by techniques known by those skilled in the art.
The prosthetic valve 100 of the present disclosure includes an expandable valve frame 102 and an expandable stent anchoring frame 104 coupled to the valve frame 102. In some embodiments, the valve frame 102 can be positioned distal to the stent anchoring frame 104, where the valve frame 102 is coupled to a distal end 144 of the stent anchoring frame 104. In some embodiments, the valve frame 102 and the stent anchoring frame 104 can be self-expandable. The valve frame 102, the stent anchoring frame 104, and/or portions of the valve frame 102 and stent anchoring frame 104 can also be balloon expandable. In various embodiments, the valve frame 102 can be self-expandable while the stent anchoring frame 104 can be balloon expandable. Other configurations are also possible.
Examples of self-expanding frames include those formed from temperature-sensitive memory alloy which change shape at a designated temperature or temperature range. Alternatively, the self-expanding frames can include those having a spring-bias. Examples of suitable materials include, but are not limited to, medical grade stainless steel (e.g., 316L), titanium, tantalum, platinum alloys, niobium alloys, cobalt alloys, alginate, or combinations thereof. Examples of shape-memory materials include shape memory plastics, polymers, and thermoplastic materials which are inert in the body. Shape memory alloys having superelastic properties generally made from ratios of nickel and titanium, commonly known as Nitinol, are also possible materials.
In addition, the valve frame 102 includes valve frame members 105 while the stent anchoring frame 104 includes stent frame members 106. For the various embodiments, the valve frame members 105 and the stent frame members 106 can have similar and/or different cross-sectional geometries along the prosthetic valve 100 length. The similarity and/or the differences in the cross-sectional geometries can be based on one or more desired functions to be elicited from each portion of the valve frame 102 and/or the stent anchoring frame 104. Examples of cross-sectional geometries include rectangular, non-planar configuration, round (e.g., circular, oval, and/or elliptical), polygonal, arced, and tubular. Other cross-sectional geometries are possible.
The valve frame 102 and stent anchoring frame 104 of the present disclosure can include stent frame members 106 and valve frame members 105 that provide adequate radial stiffness when in the expanded, or deployed, state. Adequate radial stiffness includes enough stiffness to ensure that the valve frame 102 and stent anchoring frame 104 maintain a cylindrical shape.
As discussed herein, a prosthetic valve 100 implanted to replace, for example, an aortic valve, can experience a large amount of in situ pressure with the backflow as well as the inflow of fluid through the prosthetic valve 100. The stent anchoring frame 104 is provided to reduce the likelihood that the prosthetic valve 100 will migrate after the prosthetic valve 100 is delivered and implanted at a delivery site, as well as throughout the life of the prosthetic valve 100. The stent anchoring frame 104 also can provide the ability to reposition the prosthetic valve 100 during a delivery procedure.
The stent anchoring frame 104 stent frame members 106 define a first portion 108 and a second portion 110. The second portion 110 has greater flexibility than the first portion 108, as discussed further herein. The greater flexibility of the second portion 110 can help the stent anchoring frame 104 to conform to a treatment site (e.g., body lumen) in which it is placed. By conforming to the treatment site, the stent anchoring frame 104 can better anchor into the treatment site, as compared to a stent anchoring frame 104 with uniform but lesser flexibility, preventing the movement of the prosthetic valve 100 when in use.
The stent anchoring frame 104, as illustrated in
The first portion 108 of the stent anchoring frame 104 can include connectors 112 positioned between each apex 114 formed by the stent frame members 106. By having the connectors 112 positioned between each apex 114 formed by the stent frame member 106 in the first portion 108, the first portion 108 of the stent anchoring frame 104 has a contiguous surface. As used herein, a “contiguous surface” is defined as a surface with no free apexes; in other words, each apex 114 is connected to an adjacent stent frame member 106 by a connector 112. For example, as shown in
As illustrated in
In some embodiments, the first portion 108 can consist of more than two stent frame members 106. In addition, because the connectors 112 are positioned at each apex 114 formed by the two stent frame members 106, the first portion 108 of the stent anchoring frame 104 is relatively stiff, or inflexible, as compared to the second portion 110 of the stent anchoring frame 104, as discussed herein. In addition, because the connectors 112 are positioned at each apex 114 formed by the stent frame members 106, a force applied to the first portion 108 can transmit the load throughout the first portion 108 uniformly, as discussed herein.
The strength and/or flexibility of the first portion 108 and the second portion 110 of the stent anchoring frame 104, however, can be adjusted by, for example, adjusting the number of frame members 106. As used herein, the “strength” of the various portions of the prosthetic valve 100 is defined as the ability to resist strain and/or stress. As used herein, the “flexibility” of the various portions of the prosthetic valve 100 is defined as the capability of being bent without breaking and/or becoming permanently deformed.
As will be appreciated, as the number of stent frame members 106 is increased in the first portion 108, the flexibility can decrease and the strength can increase. In addition, the strength and/or flexibility can be adjusted by changing the thickness of the stent frame members 106 and/or by changing the cross-sectional shape of the stent frame members 106. For example, by decreasing the thickness of the stent frame members 106, the flexibility of the first portion 108 can increase while the strength can decrease. The strength and flexibility properties of the stent anchoring frame 104 can also be determined by the material forming the stent anchoring frame 104.
As discussed herein, the second portion 110 of the stent frame 104 has greater flexibility than the first portion 108. The difference in flexibility between the first portion 108 and second portion 110 can be accomplished in several ways. For example, as illustrated in
By having the connectors 112 positioned between each apex 114 formed by the stent frame member 106 in the first portion 108, the first portion 108 is less flexible than the second portion 110. In addition, having the connectors 112 positioned between less than each apex 114 formed by the stent frame members 106 in the second portion 110 produces a second portion 110 with free apices 116. As discussed herein, the contiguous surface of the first portion 108 allows for the repositionability of the prosthetic valve 100, however, once the second portion 110 of the stent anchoring frame 104 is allowed to expand, the free apices 116 of the second portion 110 can prevent any further repositioning or realignment.
In other embodiments, the flexibility of the second portion 110 can be modified by using a more flexible material in forming the stent frame members 106, and/or by forming the second portion 110 stent frame members 106 with a smaller cross-sectional diameter as compared to the first portion 108 stent frame members 106.
In some embodiments, the greater flexibility of the second portion 110 of the stent anchoring frame 104 can increase the likelihood that the stent anchoring frame 104 will conform to curves and/or irregularities in a surface of a body lumen. By conforming with the body lumen, the second portion 110 of the stent anchoring frame 104 can more aptly embed itself into the body lumen wall, preventing migration of the stent anchoring frame 104, and thereby the valve frame 102.
As shown in
Similar to the first portion 108 of the stent anchoring frame 104, the flexibility and/or strength of the second portion 110 can be adjusted by changing the thickness of the frame members 106, by changing the cross-sectional shape of the frame members 106, and/or by choosing a material with the desired flexibility and strength. In addition, the flexibility and/or strength can be tuned to the desired value by increasing or decreasing the number of connectors 112 between the apices 114 formed by the stent frame members 106. By increasing the number of connectors 112, the flexibility can be reduced, while the strength can be increased.
In some embodiments, the stent anchoring frame 104 can include a covering around at least a portion of the exterior surface of the stent anchoring frame 104. The covering can be formed of, for example, expanded polytetrafluoroethylene (ePTFE), or other materials.
As shown in
The high flexibility stent frame member 215 is a thinner stent frame member 206 and contains additional structural undulations as compared to the low flexibility stent frame member 217. By forming the high flexibility stent frame member 215 as such, both the high and low flexibility stent frame members 215, 217 can expand to the same radial dimension and have uniform radial strength along the length of the stent anchor frame 204. However, the high flexibility stent frame members 215 can have more flexibility in the longitudinal direction.
In addition, by including the alternating stent frame members 206 as shown in
In addition, although not illustrated, one skilled in the art would appreciate that the second portion 210 of the stent anchoring frame 204 has greater flexibility than the first portion of the stent anchoring frame 204 when the first portion consists of low flexibility stent frame members 217.
As one skilled in the art will appreciate,
In some embodiments, the configuration of high flexibility stent frame members 215 and low flexibility stent frame members 217 can be used to create a stent anchoring frame 204 with different diameters along the longitudinal length of the stent anchoring frame 204. In various embodiments, the length of one of the alternating stent frame members, for example, the high flexibility stent frame members 215 can be increased to cause the, for example, high flexibility stent frame members 215 to expand to a larger dimension as compared to the low flexibility stent frame members 217.
As shown in
As shown in
Since the stent anchoring frame 304 shown in
As discussed herein, the stent anchoring frame 304 can be generally cylindrical. In some embodiments, the proximal end 324 of the second portion 310 of the stent anchoring frame 304 can flare in a radially outward direction from a center axis 326 of the stent anchoring frame 304. In some embodiments, the most-proximal frame member 328 of the second portion 310 can expand to a deployed diameter larger than the deployed diameter of the other stent frame members 306. In various embodiments, more than one stent frame member 306 at the proximal end 324 of the second portion 310 can expand to a deployed diameter larger than the deployed diameter of the other stent frame members 306.
In some embodiments, portions of the stent anchoring frame 304 can expand to different diameters. For example, the stent anchoring frame 304 can have a middle portion 329 that expands to a larger diameter than two end portions 330, producing a bulbous shaped middle portion 329. On the other hand, the two end portions 330 can expand to a larger diameter than the middle portion 329. In addition, the stent anchoring frame 304 can expand to a different diameter than the valve frame included in the prosthetic heart valve. Other configurations are also possible.
In some embodiments, the different diameters can be accomplished by including stent frame members 306 formed of different materials, or of similar materials but with different post-processing. In various embodiments, stent frame members 306 having a longer length can be compressed to a greater degree as compared to stent frame members 306 with a shorter length, where the stent frame members 306 with a longer length can expand to a larger diameter once allowed to expand, as discussed herein with respect to
Referring back to
As shown in
In one embodiment, the leaflets 132 can be derived from autologous, allogeneic, or xenograft material. As will be appreciated, sources for xenograft material (e.g., cardiac valves) include, but are not limited to, mammalian sources such as porcine, equine, bovine, and sheep. Additional biologic materials from which to form the valve leaflets 104 include, but are not limited to, explanted veins, pericardium, facia lata, harvested cardiac valves, bladder, vein wall, various collagen types, elastin, intestinal submucosa, and decellularized basement membrane materials, such as small intestine submucosa (SIS), amniotic tissue, or umbilical vein.
Alternatively, the leaflets 132 can be formed from a synthetic material. Possible synthetic materials include, but are not limited to, expanded polytetrafluoroethylene (ePTFE), polytetrafluoroethylene (PTFE), polystyrene-polyisobutylene-polystyrene (SIBS), polyurethane, segmented poly(carbonate-urethane), polyester, polyethylene (PE), polyethylene terephthalate (PET), silk, urethane, Rayon, Silicone, or the like. In an additional embodiment, the synthetic material can also include metals, such as stainless steel (e.g., 316L) and nitinol. These synthetic materials can be in a woven, a knit, a cast, or other known physical fluid-impermeable or permeable configurations. In addition, plated metals (e.g., gold, platinum, rhodium) can be embedded in the leaflet 132 material (e.g., a sandwich configuration) to allow for visualization of the leaflets 132 post placement.
The leaflets 132 can also be formed of any combination of these exemplary materials, or these materials in combination with other materials, as are known in the art. A variety of known treatments and/or coatings can also be included in the leaflets 132.
The valve frame 102, as shown in
As illustrated, the valve frame members 105 are coupled together such that all valve frame free edges 138 point in a direction towards the distal end 134 of the prosthetic valve 100. By forming the valve frame 102 so that all of the valve frame free edges 138 point in the direction towards the distal end 134 of the prosthetic valve 100, the first portion 108 of the stent anchoring frame 104 and the valve frame 102 define a length 140 of the prosthetic valve 100 that has a contiguous surface, as discussed herein. The contiguous surface allows a delivery device to repeatedly slide over the length 140 in its entirety in two longitudinal directions when the first portion 108 of the stent anchoring frame 104 and the valve frame 102 are in a partially expanded state during delivery from the delivery device, as discussed further herein.
As discussed herein, the valve frame 102 of the present disclosure can include valve frame members 105 that provide adequate radial stiffness when in the expanded, or deployed, state. Adequate radial stiffness includes enough stiffness to ensure that the valve frame 102 maintains a cylindrical shape, which ensures that the leaflets 132 close and open properly. Adequate radial stiffness can also ensure that there will be no parevalvular leakage, in other words, no leaking between the valve 100 and the aorta interface. Radial stiffness also can ensure that sufficient interaction between the prosthetic valve 100 and body lumen wall is provided so as to minimize the chance of prosthetic valve 100 migration as the prosthetic valve 100 closes and holds full body blood pressure.
In some embodiments, the valve frame 102 can include a transition zone 142, where the transition zone 142 is positioned between the valve leaflets 132 and the stent anchoring frame 104, and is coupled to a distal end 144 of the stent anchoring frame 104. As shown in
In various embodiments, the transition zone 142 can include transition zone members 146 coupled to the distal end 144 of the stent anchoring frame 104. The transition zone members 146 can be useful in distributing the load on the valve frame 102 to the stent anchoring frame 104 due to liquid going through the valve frame 102. As discussed herein, the first portion 108 of the stent anchoring frame 104 can include connectors 112 positioned at each apex 114 formed by the stent frame members 106. As liquid goes through the valve frame 102, the transition zone members 146 can transmit the load to the stent anchoring frame 104, where the configuration of the first portion 108 transmits the load throughout the first portion 108 uniformly. As such, the transition zone members 146 can be formed of a rigid material to keep the distance between the valve frame 102 and the stent anchoring frame 104 approximately static.
In some embodiments, the transition zone members 146 can be formed such that the transition zone members 146 have a high fatigue life, some compression strength, and high tensile strength. In some embodiments, the transition zone members 146 can be formed of a cable that is flexible in the radial direction but is inflexible in the longitudinal direction. In some embodiments, the transition zone members 146 can be formed of a braided member. In various embodiments, the transition zone members 146 can be formed of a cable around a solid core. As shown in
In some embodiments, the valve frame 102 can include a support ring 148 on the distal end 134 of the valve frame 102. Including the support ring 148 can reduce the amount of valve frame members 105 included in the valve frame 102. In addition, in some embodiments, the support ring 148 can flare in a radially outward direction from the center axis 126. In addition, embodiments of the valve frame 102 without the support ring 148 can include the distal end 134 of the valve frame 102 flared in a radially outward direction from the center axis 126.
In some embodiments, the valve frame 102 can include a fabric tube surrounding the exterior surface of the valve frame 102. The fabric tube can increase the likelihood that the valve frame 102 can form a fluid-tight seal at a body lumen wall. In other words, the fabric tube can prevent liquid from flowing around the valve frame 102 rather than through the valve frame 102.
The prosthetic valve 100 can further include one or more radio-opaque markers (e.g., tabs, sleeves, welds). For example, one or more portions of the valve frame 102 and/or stent anchoring frame 104 can be formed from a radio-opaque material. Radio-opaque markers can be attached to and/or coated onto one or more locations along the valve frame 102 and/or stent anchoring frame 104. Examples of radio-opaque materials include, but are not limited to, gold, tantalum, and platinum. The position of the one or more radio-opaque markers can be selected so as to provide information on the position, location, and orientation of the prosthetic valve 100 during its implantation.
As will be appreciated, the prosthetic valve 100 can be treated and/or coated with any number of surface or material treatments. Examples of such treatments include, but are not limited to, bioactive agents, including those that modulate thrombosis, those that encourage cellular ingrowth, throughgrowth, and endothelialization, those that resist infection, and those that reduce calcification.
In some embodiments, the prosthetic valve 100 can include one or more structures and/or subcomponents fabricated from a sheet and/or billet, for example, by stamping, drilling, cutting, forging, shearing, machining, etching, and the like.
In some embodiments, the valve frame 102 can include securing members for securing the prosthetic valve 100 to a body lumen, including, but not limited to, hooks, barbs, spikes, protrusions, and the like. The securing members can be disposed on the valve frame 102 and/or stent anchoring frame 104 at or around the exterior or at the proximal end 124 of the stent anchoring frame 104, the distal end 144 of the stent anchoring frame 104, and/or the distal end 134 of the valve frame 102. In some embodiments, the valve frame 102 includes one or more biologically active compounds and/or active chemical entities known in the art, for example, a drug, therapeutic agent, anti-coagulant, anti-proliferant, anti-inflammatory agent, and/or tissue growth modulating agent.
As shown in
In other aspects of the present disclosure, delivery devices for delivering a prosthetic valve to a treatment location in a body lumen are provided, as are methods for their use. The delivery devices, or systems, are particularly adapted for use in minimally invasive, interventional procedures, such as percutaneous aortic valve replacements.
In the embodiments illustrated in
As shown in
In addition, the first retractable sheath 662 can move longitudinally (e.g., slide) relative the elongate delivery catheter 660 to allow the prosthetic valve 600 to radially expand from its delivery state to its deployed state. In some embodiments, moving the first retractable sheath 662 relative the elongate delivery catheter 660 can be accomplished by pulling a proximal end 666 of the first retractable sheath 662 toward a proximal end 668 of the elongate delivery catheter 660.
In some embodiments, the first retractable sheath 662 can include an inner lining on the inside surface of the first retractable sheath 662. An inner lining can decrease the friction between the prosthetic valve 600 and the first retractable sheath 662 while also sealing the first retractable sheath 662. The inner lining can be formed of, for example, Nylon, Dacron, expanded polytetrafluoroethylene (ePTFE), and/or other materials.
The first retractable sheath 662 can have many possible configurations. For example, in some embodiments, the first retractable sheath 662 can be a flexible tube formed of a metal, metal-alloy, and/or polymers, such as polyvinyl chloride, polyethylene, polyethylene terephalate, polyamide, mixtures, and block-copolymers thereof.
Returning to
In some embodiments, the diameter of the valve frame 602 and/or the stent anchoring frame 604, when deployed, can be provided with a dimension that is from zero (0) to twenty-five (25) percent larger than the dimension of the body lumen. Once deployed, the valve frame 602 and/or the stent anchoring frame 604 can expand the dimension of the body lumen at the treatment location. In this way, the prosthetic valve 600 can reduce the possibility of fluid leakage around the periphery of the prosthetic valve 600. In addition, due to the strength and rigidity of the prosthetic valve 600, the prosthetic valve 600 can have proper apposition to the body lumen to reduce the likelihood of migration of the prosthetic valve 600 once employed.
Once the valve frame 602 is expanded, the position and alignment of the valve frame 602 can be monitored to determine whether it is in a satisfactory position. If the valve frame 602 is not positioned correctly, embodiments of the present disclosure provide for the repositioning of the prosthetic valve 600.
In some embodiments, the second retractable sheath 664 can be positioned proximal to the first retractable sheath 662. The second retractable sheath 664 can be delivered to the treatment site in a delivery state, and can be expanded when the valve frame 602 has been deployed to reposition the valve frame 602. In some embodiments, the second retractable sheath 664 can be a wallstent, where the distal and proximal ends of the wallstent are pushed towards each other to expand the diameter of the wallstent.
In various embodiments, the second retractable sheath 664 can be heat set in the delivery state, as shown in
For example, the second retractable sheath 664 can include cables 672 attached to the distal end 674 of the second retractable sheath 664 and an expandable member 676 coupled to the proximal end 678 of the second retractable sheath 664. The cables 672 can be pulled toward the proximal end 668 of the elongate delivery catheter 660 while the expandable member 676 can be pushed toward the distal end 680 of the elongate delivery catheter 660. In some embodiments, the expandable member 676 can include fingers 682 coupled to the proximal end 678 of the second retractable sheath 664 that can separate as the second retractable sheath 664 expands.
In some embodiments, the second retractable sheath 664 can be heat set in an expanded state, as discussed herein, where the second retractable sheath 664 can be delivered under strain using an outer sheath, and can be expanded by retracting the outer sheath.
As shown in
In some embodiments, the second retractable sheath 664 can be formed of ring structure, where a number of expandable rings are connected by a flexible tube. The expandable rings can be delivered with a diameter of about five (5) mm and then expand to a diameter of about ten (10) mm to enable the second sheath to function as a repositioning device. In some embodiments, the second retractable sheath 664 can be lined with a low friction surface that can easily slide over the first portion 608 of the stent anchoring frame 604 and/or the valve frame 602, for example, ePTFE.
As illustrated in
Once the prosthetic valve 600 is re-constrained in the second sheath 664, the prosthetic valve 600 can be repositioned and the second sheath 664 can be retracted to re-deploy the valve frame 602. This process can be repeated until the position, stability, and functioning of the valve frame 602 is satisfactory. Once the valve frame 602 is in a satisfactory position, the second retractable sheath 664 and the first retractable sheath 662 can be retracted to allow the prosthetic valve 600 to fully expand, as illustrated in
To remove the system 658, the second retractable sheath 664 can be contracted by releasing the expandable member 676 coupled to the proximal end 678 of the second retractable sheath and the cables 672 holding the second retractable sheath 664 in place. Once the second retractable sheath 664 returns to the delivery state, the system 658 can be removed.
In embodiments where the second retractable sheath 664 is delivered with an outer sheath to constrain the second retractable sheath, the system 658 can be removed by contracting the second retractable sheath 664 by pulling the expandable member 676 coupled to the proximal end 678 of the second retractable sheath toward the proximal end 668 of the elongate delivery catheter 660 while the cables 672 hold the second retractable sheath 664 in place. Once the second retractable sheath 664 is contracted, the system 658 can be removed.
In some embodiments, the system 658 accomplishes the repositioning of the prosthetic valve 600 by sliding the first retractable sheath 664 over the deployed valve frame 602 rather than including a second retractable sheath 664. In such embodiments, the transition zone members 646 can be formed with an increased strength to hold the valve frame 602 in place while the valve frame 602 is contracted from a diameter of about twenty-five (25) mm to about five (5) mm.
In some embodiments, the elongate delivery catheter 660 can include a distal tip 686. The distal tip 686 can have a conical configuration, where the tip diameter decreases in size to a point at the distal end 680 of the elongate delivery catheter 660. For example, the system 658 can have a five (5) mm diameter at the prosthetic valve 600, and decrease to a two (2) mm diameter at the distal end 680 of the elongate delivery catheter 660.
As discussed herein, the prosthetic valve 600 can be formed of a self-expandable material or a material with a spring bias, where the prosthetic valve 600 can expand when the first retractable sheath 662 and/or second retractable sheath 664 has been removed. In some embodiments, an expandable balloon can be included to secure the prosthetic valve 600 inside a body lumen.
In some embodiments, the expandable balloon can be a perfusion balloon. A perfusion balloon can be used to radially expand the valve frame 602 while allowing fluid, for example, blood, to pass through the delivery catheter 660 and prosthetic valve 600 while the prosthetic valve 600 is being positioned in the vasculature.
The delivery catheter 660 can be formed of a number of materials. Materials include polymers, such as PVC, PE, PET, polyamide, mixtures, and block co-polymers thereof, as discussed herein with respect to the first retractable sheath 662. In addition, each of the delivery catheter 660, the first retractable sheath 662, and/or the second retractable sheath 664 can have a wall thickness and an inner diameter sufficient to allow the structures to slide longitudinally relative each other, as described herein, and to maintain the prosthetic valve 600 in a delivery state, as discussed herein.
In an additional embodiment, the prosthetic valve 600 can further include a sealing material positioned on the periphery of the valve frame 602. In one embodiment, once implanted, the sealing material can swell due the presence of liquid to occupy volume between the valve frame 602 and the tissue on which the prosthetic valve 600 has been implanted so as to prevent leakage of the liquid around the outside of the prosthetic valve 600.
A variety of suitable materials for the sealing material are possible. For example, the sealing material can be selected from the general class of materials that include polysaccharides, proteins, and biocompatible gels. Specific examples of these polymeric materials can include, but are not limited to, those derived from poly(ethylene oxide) (PEO), poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone) (PVP), poly(ethyloxazoline) (PEOX) polyaminoacids, pseudopolyamino acids, and polyethyloxazoline, as well as copolymers of these with each other or other water soluble polymers or water insoluble polymers. Examples of the polysaccharide include those derived from alginate, hyaluronic acid, chondroitin sulfate, dextran, dextran sulfate, heparin, heparin sulfate, heparan sulfate, chitosan, gellan gum, xanthan gum, guar gum, water soluble cellulose derivatives, and carrageenan. Examples of proteins include those derived from gelatin, collagen, elastin, zein, and albumin, whether produced from natural or recombinant sources.
In some embodiments, the stent anchoring frame 604 can include a sealing band surrounding the stent anchoring frame 604 to prevent leakage of liquid around the outside of the prosthetic valve 600. The sealing band may comprise a relatively soft biocompatible material, such as polyurethane or other polymer. In some embodiments, the sealing band can be porous or is otherwise capable of expanding or swelling when exposed to fluids, thereby enhancing the ability of the sealing band. The sealing band may include a functional composition such as an adhesive, a fixative, or therapeutic agent such as a drug or other materials.
The embodiments of the prosthetic valve 600 described herein may be used to replace, supplement, or augment valve structures within one or more lumens of the body. For example, embodiments of the present invention may be used to replace an incompetent cardiac valve of the heart, such as the aortic and/or pulmonary valves of the heart. In one embodiment, the native cardiac valve can either remain in place or be removed (e.g., via a valvoplasty procedure) prior to implanting the cardiac valve of the present disclosure.
In addition, positioning the system 658 having the prosthetic valve 600 as discussed herein includes introducing the system into the cardiovascular system of the patient using minimally invasive percutaneous, transluminal techniques. For example, a guidewire can be positioned within the cardiovascular system of a patient that includes the predetermined location. The system 658 of the present disclosure, including the prosthetic valve 600 as described herein, can be positioned over the guidewire and the system 658 advanced so as to position the prosthetic valve 600 at or adjacent the predetermined location. In one embodiment, radio opaque markers on the catheter 660 and/or the prosthetic valve 600, as described herein, can be used to help locate and position the prosthetic valve 600.
The prosthetic valve 600 can be deployed from the system at the predetermined location in any number of ways, as described herein. In one embodiment, the prosthetic valve 600 of the present disclosure can be deployed and placed in any number of cardiovascular locations. For example, the prosthetic valve 600 can be deployed and placed within a major artery of a patient. In one embodiment, major arteries include, but are not limited to, the aorta. In addition, valves of the present invention can be deployed and placed within veins. Other locations are also possible.
Once implanted, the prosthetic valve 600 can provide sufficient contact with the body lumen wall to allow the leaflets 632 to prevent retrograde flow between the prosthetic valve 600 and the body lumen wall. In addition, the stent anchoring frame 604 can securely locate the prosthetic valve 600 and prevent migration of the prosthetic valve 600. The prosthetic valve 600 described herein also displays sufficient flexibility and resilience so as to accommodate changes in the body lumen diameter, while maintaining the proper placement of prosthetic valve 600. As described herein, the prosthetic valve 600 can engage the lumen so as to reduce the volume of retrograde flow through and around prosthetic valve 600. It is, however, understood that some leaking or fluid flow may occur between the valve frame 602 and the body lumen and/or through valve leaflets 632.
While the present invention has been shown and described in detail above, it will be clear to the person skilled in the art that changes and modifications may be made without departing from the spirit and scope of the invention. As such, that which is set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined by the following claims, along with the full range of equivalents to which such claims are entitled. In addition, one of ordinary skill in the art will appreciate upon reading and understanding this disclosure that other variations for the invention described herein can be included within the scope of the present invention.
In the foregoing Detailed Description, various features are grouped together in several embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
This application is a continuation of U.S. application Ser. No. 15/416,669, filed Jan. 26, 2017, which is a continuation of U.S. application Ser. No. 12/005,881, filed Dec. 28, 2007.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15416669 | Jan 2017 | US |
| Child | 16139868 | US | |
| Parent | 12005881 | Dec 2007 | US |
| Child | 15416669 | US |
