US20050137687A1 - Heart valve anchor and method - Google Patents

Abstract

Apparatus for endovascularly replacing a patient's heart valve. In some embodiments the apparatus includes an expandable anchor with a lip region and a skirt region; and a replacement valve, wherein the lip region and skirt region are configured for percutaneous expansion to engage leaflets of the heart valve. The invention is also a method for endovascularly replacing a patient's heart valve. In some embodiments the method includes the steps of endovascularly delivering apparatus including an anchor having lip and skirt regions, and a replacement valve coupled to the anchor, to a vicinity of the heart valve in a collapsed delivery configuration; and expanding the apparatus such that leaflets of the heart valve are captured between the lip and skirt regions of the anchor.

Description

BACKGROUND OF THE INVENTION
• The present invention relates to methods and apparatus for endovascularly replacing a heart valve. More particularly, the present invention relates to methods and apparatus for endovascularly replacing a heart valve with a replacement valve using an expandable and retrievable anchor.
• Heart valve surgery is used to repair or replace diseased heart valves. Valve surgery is an open-heart procedure conducted under general anesthesia. An incision is made through the patient's sternum (sternotomy), and the patient's heart is stopped while blood flow is rerouted through a heart-lung bypass machine.
• Valve replacement may be indicated when there is a narrowing of the native heart valve, commonly referred to as stenosis, or when the native valve leaks or regurgitates. When replacing the valve, the native valve is excised and replaced with either a biologic or a mechanical valve. Mechanical valves require lifelong anticoagulant medication to prevent blood clot formation, and clicking of the valve often may be heard through the chest. Biologic tissue valves typically do not require such medication. Tissue valves may be obtained from cadavers or may be porcine or bovine, and are commonly attached to synthetic rings that are secured to the patient's heart.
• Valve replacement surgery is a highly invasive operation with significant concomitant risk. Risks include bleeding, infection, stroke, heart attack, arrhythmia, renal failure, adverse reactions to the anesthesia medications, as well as sudden death. 2-5% of patients die during surgery.
• Post-surgery, patients temporarily may be confused due to emboli and other factors associated with the heart-lung machine. The first 2-3 days following surgery are spent in an intensive care unit where heart functions can be closely monitored. The average hospital stay is between 1 to 2 weeks, with several more weeks to months required for complete recovery.
• In recent years, advancements in minimally invasive surgery and interventional cardiology have encouraged some investigators to pursue percutaneous replacement of the aortic heart valve. Percutaneous Valve Technologies (“PVT”) of Fort Lee, N.J., has developed a balloon-expandable stent integrated with a bioprosthetic valve. The stent/valve device is deployed across the native diseased valve to permanently hold the valve open, thereby alleviating a need to excise the native valve and to position the bioprosthetic valve in place of the native valve. PVT's device is designed for delivery in a cardiac catheterization laboratory under local anesthesia using fluoroscopic guidance, thereby avoiding general anesthesia and open-heart surgery. The device was first implanted in a patient in April of 2002.
• PVT's device suffers from several drawbacks. Deployment of PVT's stent is not reversible, and the stent is not retrievable. This is a critical drawback because improper positioning too far up towards the aorta risks blocking the coronary ostia of the patient. Furthermore, a misplaced stent/valve in the other direction (away from the aorta, closer to the ventricle) will impinge on the mitral apparatus and eventually wear through the leaflet as the leaflet continuously rubs against the edge of the stent/valve.
• Another drawback of the PVT device is its relatively large cross-sectional delivery profile. The PVT system's stent/valve combination is mounted onto a delivery balloon, making retrograde delivery through the aorta challenging. An antegrade transseptal approach may therefore be needed, requiring puncture of the septum and routing through the mitral valve, which significantly increases complexity and risk of the procedure. Very few cardiologists are currently trained in performing a transseptal puncture, which is a challenging procedure by itself.
• Other prior art replacement heart valves use self-expanding stents as anchors. In the endovascular aortic valve replacement procedure, accurate placement of aortic valves relative to coronary ostia and the mitral valve is critical. Standard self-expanding systems have very poor accuracy in deployment, however. Often the proximal end of the stent is not released from the delivery system until accurate placement is verified by fluoroscopy, and the stent typically jumps once released. It is therefore often impossible to know where the ends of the stent will be with respect to the native valve, the coronary ostia and the mitral valve.
• Also, visualization of the way the new valve is functioning prior to final deployment is very desirable. Visualization prior to final and irreversible deployment cannot be done with standard self-expanding systems, however, and the replacement valve is often not fully functional before final deployment.
• Another drawback of prior art self-expanding replacement heart valve systems is their lack of radial strength. In order for self-expanding systems to be easily delivered through a delivery sheath, the metal needs to flex and bend inside the delivery catheter without being plastically deformed. In arterial stents, this is not a challenge, and there are many commercial arterial stent systems that apply adequate radial force against the vessel wall and yet can collapse to a small enough of a diameter to fit inside a delivery catheter without plastically deforming. However when the stent has a valve fastened inside it, as is the case in aortic valve replacement, the anchoring of the stent to vessel walls is significantly challenged during diastole. The force to hold back arterial pressure and prevent blood from going back inside the ventricle during diastole will be directly transferred to the stent/vessel wall interface. Therefore the amount of radial force required to keep the self expanding stent/valve in contact with the vessel wall and not sliding will be much higher than in stents that do not have valves inside of them. Moreover, a self-expanding stent without sufficient radial force will end up dilating and contracting with each heartbeat, thereby distorting the valve, affecting its function and possibly migrating and dislodging completely. Simply increasing strut thickness of the self-expanding stent is not a practical solution as it runs the risk of larger profile and/or plastic deformation of the self-expanding stent.
• U.S. patent application Serial No. 2002/0151970 to Garrison et al. describes a two-piece device for replacement of the aortic valve that is adapted for delivery through a patient's aorta. A stent is endovascularly placed across the native valve, then a replacement valve is positioned within the lumen of the stent. By separating the stent and the valve during delivery, a profile of the device's delivery system may be sufficiently reduced to allow aortic delivery without requiring a transseptal approach. Both the stent and a frame of the replacement valve may be balloon-expandable or self-expanding.
• While providing for an aortic approach, devices described in the Garrison patent application suffer from several drawbacks. First, the stent portion of the device is delivered across the native valve as a single piece in a single step, which precludes dynamic repositioning of the stent during delivery. Stent foreshortening or migration during expansion may lead to improper alignment.
• Additionally, Garrison's stent simply crushes the native valve leaflets against the heart wall and does not engage the leaflets in a manner that would provide positive registration of the device relative to the native position of the valve. This increases an immediate risk of blocking the coronary ostia, as well as a longer-term risk of migration of the device post-implantation. Furtherstill, the stent comprises openings or gaps in which the replacement valve is seated post-delivery. Tissue may protrude through these gaps, thereby increasing a risk of improper seating of the valve within the stent.
• In view of drawbacks associated with previously known techniques for endovascularly replacing a heart valve, it would be desirable to provide methods and apparatus that overcome those drawbacks.
SUMMARY OF THE INVENTION
• The invention provides apparatus and methods for endovascularly replacing a patient's heart valve. One aspect of the invention provides an apparatus including: an expandable anchor with a lip region and a skirt region; and a replacement valve, wherein the lip region and skirt region are configured for percutaneous expansion (e.g., independent expansion or concurrent expansion) to engage leaflets of the heart valve. The lip and/or skirt regions may be adapted to preclude migration of the apparatus post-deployment and expansion. Expansion of the anchor and replacement valve may be by balloon-expansion, self-expansion, and combinations thereof. A locking element may be provided to maintain expansion.
• The invention also includes a delivery system that facilitates deployment and expansion of the apparatus to endovascularly replace the heart valve and, in some embodiments, retrieve the apparatus.
• Another aspect of the invention provides a method for endovascularly replacing a patient's heart valve. In some embodiments the method includes the steps of: endovascularly delivering apparatus having an anchor having lip and skirt regions, and a replacement valve coupled to the anchor, to a vicinity of the heart valve in a collapsed delivery configuration; and expanding the apparatus such that leaflets of the heart valve are captured between the lip and skirt regions of the anchor. The expanding step of the method may include the step of dynamically repositioning the apparatus relative to the heart valve prior to capturing the leaflets. The expanding step may also include the steps of expanding either the lip region or the skirt region, positively engaging the heart valve with the expanded lip or skirt region, and then expanding the unexpanded region. The apparatus may be retrieved, repositioned and redeployed, and the apparatus may be locked in its expanded configuration.
INCORPORATION BY REFERENCE
• All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
• The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
• FIGS.1A-B are elevational views of a replacement heart valve and anchor according to one embodiment of the invention.
• FIGS.2A-B are sectional views of the anchor and valve ofFIG. 1.
• FIGS.3A-B show delivery and deployment of a replacement heart valve and anchor, such as the anchor and valve ofFIGS. 1 and 2.
• FIGS.4A-E also show delivery and deployment of a replacement heart valve and anchor, such as the anchor and valve ofFIGS. 1 and 2.
• FIGS.5A-F show the use of a replacement heart valve and anchor to replace an aortic valve.
• FIGS.6A-F show the use of a replacement heart valve and anchor with a positive registration feature to replace an aortic valve.
• FIG. 7 shows the use of a replacement heart valve and anchor with an alternative positive registration feature to replace an aortic valve.
• FIGS.8A-C show another embodiment of a replacement heart valve and anchor according to the invention.
• FIGS.9A-H show delivery and deployment of the replacement heart valve and anchor ofFIG. 8.
• FIG. 10 is a cross-sectional drawing of the delivery system used with the method and apparatus ofFIGS. 8 and 9.
• FIGS.11A-C show alternative locks for use with replacement heart valves and anchors of this invention.
• FIGS.12A-C show a vessel wall engaging lock for use with replacement heart valves and anchors of this invention.
• FIG. 13 demonstrates paravalvular leaking around a replacement heart valve and anchor.
• FIG. 14 shows a seal for use with a replacement heart valve and anchor of this invention.
• FIGS.15A-E show alternative arrangements of seals on a replacement heart valve and anchor.
• FIGS.16A-C show alternative seal designs for use with replacement heart valves and anchors.
• FIG. 17 shows an alternative anchor lock embodiment in an unlocked configuration.
• FIG. 18 shows the anchor lock ofFIG. 17 in a locked configuration.
• FIG. 19 shows an alternative anchor deployment tool attachment and release mechanism for use with the invention.
• FIG. 20 shows the attachment and release mechanism ofFIG. 19 in the process of being released.
• FIG. 21 shows the attachment and release mechanism ofFIGS. 19 and 20 in a released condition.
• FIG. 22 shows an alternative embodiment of a replacement heart valve and anchor and a deployment tool according to the invention in an undeployed configuration.
• FIG. 23 shows the replacement heart valve and anchor ofFIG. 22 in a partially deployed configuration.
• FIG. 24 shows the replacement heart valve and anchor ofFIGS. 22 and 23 in a more fully deployed configuration but with the deployment tool still attached.
• FIG. 25 shows yet another embodiment of the delivery and deployment apparatus of the invention in use with a replacement heart valve and anchor.
• FIG. 26 shows the delivery and deployment apparatus ofFIG. 25 in the process of deploying a replacement heart valve and anchor.
• FIG. 27 show an embodiment of the invention employing seals at the interface of the replacement heart valve and anchor and the patient's tissue.
• FIG. 28 is a longitudinal cross-sectional view of the seal shown inFIG. 27 in compressed form.
• FIG. 29 is a transverse cross-sectional view of the seal shown inFIG. 28.
• FIG. 30 is a longitudinal cross-sectional view of the seal shown inFIG. 27 in expanded form.
• FIG. 31 is a transverse cross-sectional view of the seal shown inFIG. 30.
• FIG. 32 shows yet another embodiment of the replacement heart valve and anchor of this invention in an undeployed configuration.
• FIG. 33 shows the replacement heart valve and anchor ofFIG. 32 in a deployed configuration.
• FIG. 34 shows the replacement heart valve and anchor ofFIGS. 32 and 33 deployed in a patient's heart valve.
• FIGS.35A-H show yet another embodiment of a replacement heart valve, anchor and deployment system according to this invention.
• FIGS.36A-E show more detail of the anchor of the embodiment shown in FIGS.35A-H.
• FIGS.37A-B show other embodiments of the replacement heart valve and anchor of the invention.
• FIGS.38A-C illustrate a method for endovascularly replacing a patient's diseased heart valve.
• FIGS.39A-B show an anchor for use in a two-piece replacement heart valve and anchor embodiment of the invention.
• FIGS.40A-B show a replacement heart valve for use in a two-piece replacement heart valve and anchor embodiment of the invention.
• FIGS.41A-D show a method of coupling the anchor ofFIG. 39 and the replacement heart valve ofFIG. 40.
• FIG. 42 shows a delivery system for use with the apparatus shown inFIGS. 39-41.
• FIG. 43 shows an alternative embodiment of a delivery system for use with the apparatus shown inFIGS. 39-41.
• FIG. 44 shows yet another alternative embodiment of a delivery system for use with the apparatus shown inFIGS. 39-41.
• FIGS.45A-I illustrate a method of delivering and deploying a two-piece replacement heart valve and anchor.
• FIGS.46A-B shows another embodiment of a two-piece replacement heart valve and anchor according to this invention.
• FIG. 47 shows yet another embodiment of a two-piece replacement heart valve and anchor according to this invention.
• FIG. 48 shows yet another embodiment of a two-piece replacement heart valve and anchor according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
• While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
• With reference now toFIGS. 1-4, a first embodiment of replacement heart valve apparatus in accordance with the present invention is described, including a method of actively foreshortening and expanding the apparatus from a delivery configuration and to a deployed configuration.Apparatus10 comprisesreplacement valve20 disposed within and coupled toanchor30.FIG. 1 schematically illustrate individual cells ofanchor30 ofapparatus10, and should be viewed as if the cylindrical anchor has been cut open and laid flat.FIG. 2 schematically illustrate a detail portion ofapparatus10 in side-section.
• Anchor30 has alip region32, askirt region34 and abody region36. First, second andthird posts38a,38band38c, respectively, are coupled toskirt region34 and extend withinlumen31 ofanchor30.Posts38 preferably are spaced 120° apart from one another about the circumference ofanchor30.
• Anchor30 preferably is fabricated by using self-expanding patterns (laser cut or chemically milled), braids and materials, such as a stainless steel, nickel-titanium (“Nitinol”) or cobalt chromium but alternatively may be fabricated using balloon-expandable patterns where the anchor is designed to plastically deform to it's final shape by means of balloon expansion.Replacement valve20 is preferably from biologic tissues, e.g. porcine valve leaflets or bovine or equine pericardium tissues, alternatively it can be made from tissue engineered materials (such as extracellular matrix material from Small Intestinal Submucosa (SIS)) but alternatively may be prosthetic from an elastomeric polymer or silicone, Nitinol or stainless steel mesh or pattern (sputtered, chemically milled or laser cut). The leaflet may also be made of a composite of the elastomeric or silicone materials and metal alloys or other fibers such Kevlar or carbon.Annular base22 ofreplacement valve20 preferably is coupled toskirt region34 ofanchor30, whilecommissures24 ofreplacement valve leaflets26 are coupled to posts38.
• Anchor30 may be actuated using external non-hydraulic or non-pneumatic force to actively foreshorten in order to increase its radial strength. As shown below, the proximal and distal end regions ofanchor30 may be actuated independently. The anchor and valve may be placed and expanded in order to visualize their location with respect to the native valve and other anatomical features and to visualize operation of the valve. The anchor and valve may thereafter be repositioned and even retrieved into the delivery sheath or catheter. The apparatus may be delivered to the vicinity of the patient's aortic valve in a retrograde approach in a catheter having a diameter no more than 23 french, preferably no more than 21 french, more preferably no more than 19 french, or more preferably no more than 17 french. Upon deployment the anchor and replacement valve capture the native valve leaflets and positively lock to maintain configuration and position.
• A deployment tool is used to actuate, reposition, lock and/or retrieveanchor30. In order to avoid delivery ofanchor30 on a balloon for balloon expansion, a non-hydraulic or non-pneumatic anchor actuator is used. In this embodiment, the actuator is a deployment tool that includes distalregion control wires50, control rods ortubes60 and proximalregion control wires62.Locks40 include posts orarms38 preferably with male interlockingelements44 extending fromskirt region34 and matingfemale interlocking elements42 inlip region32. Male interlockingelements44 haveeyelets45.Control wires50 pass from a delivery system forapparatus10 through female interlockingelements42, througheyelets45 of male interlockingelements44, and back through female interlockingelements42, such that a double strand ofwire50 passes through each female interlockingelement42 for manipulation by a medical practitioner external to the patient to actuate and control the anchor by changing the anchor's shape.Control wires50 may comprise, for example, strands of suture.
• Tubes60 are reversibly coupled toapparatus10 and may be used in conjunction withwires50 to actuateanchor30, e.g., to foreshorten and lockapparatus10 in the fully deployed configuration.Tubes60 also facilitate repositioning and retrieval ofapparatus10, as described hereinafter. For example,anchor30 may be foreshortened and radially expanded by applying a distally directed force ontubes60 while proximally retractingwires50. As seen inFIG. 3,control wires62 pass through interior lumens61 oftubes60. This ensures thattubes60 are aligned properly withapparatus10 during deployment and foreshortening.Control wires62 can also actuateanchor60; proximally directed forces oncontrol wires62 contacts theproximal lip region32 ofanchor30.Wires62 also act to couple and decoupletubes60 fromapparatus10.Wires62 may comprise, for example, strands of suture.
• FIGS. 1A and 2A illustrateanchor30 in a delivery configuration or in a partially deployed configuration (e.g., after dynamic self-expansion expansion from a constrained delivery configuration within a delivery sheath).Anchor30 has a relatively long length and a relatively small width in the delivery or partially deployed configuration, as compared to the foreshortened and fully deployed configuration ofFIGS. 1B and 2B.
• InFIGS. 1A and 2A,replacement valve20 is collapsed withinlumen31 ofanchor30. Retraction ofwires50 relative totubes60 foreshortens anchor30, which increases the anchor's width while decreasing its length. Such foreshortening also properly seatsreplacement valve20 withinlumen31 ofanchor30. Imposed foreshortening will enhance radial force applied byapparatus10 to surrounding tissue over at least a portion ofanchor30. In some embodiments, the anchor exerts an outward force on surrounding tissue to engage the tissue in such way to prevent migration of anchor caused by force of blood against closed leaflet during diastole. This anchoring force is preferably 1 to 2 lbs, more preferably 2 to 4 lbs, or more preferably 4 to 10 lbs. In some embodiments, the anchoring force is preferably greater than 1 pound, more preferably greater than 2 pounds, or more preferably greater than 4 pounds. Enhanced radial force of the anchor is also important for enhanced crush resistance of the anchor against the surrounding tissue due to the healing response (fibrosis and contraction of annulus over a longer period of time) or to dynamic changes of pressure and flow at each heart beat In an alternative embodiment, the anchor pattern or braid is designed to have gaps or areas where the native tissue is allowed to protrude through the anchor slightly (not shown) and as the foreshortening is applied, the tissue is trapped in the anchor. This feature would provide additional means to prevent anchor migration and enhance long term stability of the device.
• Deployment ofapparatus10 is fully reversible untillock40 has been locked via mating of male interlockingelements44 with female interlockingelements42. Deployment is then completed bydecoupling tubes60 fromlip section32 ofanchor30 by retracting one end of eachwire62 relative to the other end of the wire, and by retracting one end of eachwire50 relative to the other end of the wire until each wire has been removed fromeyelet45 of its corresponding male interlockingelement44.
• As best seen inFIG. 2B,body region36 ofanchor30 optionally may comprisebarb elements37 that protrude fromanchor30 in the fully deployed configuration, for example, for engagement of a patient's native valve leaflets and to preclude migration of the apparatus.
• With reference now toFIG. 3, a delivery and deployment system for a self-expanding embodiment ofapparatus10 including asheath110 having alumen112. Self-expandinganchor30 is collapsible to a delivery configuration withinlumen112 ofsheath110, such thatapparatus10 may be delivered viadelivery system100. As seen inFIG. 3A,apparatus10 may be deployed fromlumen112 by retractingsheath110 relative toapparatus10,control wires50 andtubes60, which causesanchor30 to dynamically self-expand to a partially deployed configuration.Control wires50 then are retracted relative toapparatus10 andtubes60 to impose foreshortening uponanchor30, as seen inFIG. 3B.
• During foreshortening,tubes60 push againstlip region32 ofanchor30, whilewires50 pull onposts38 of the anchor.Wires62 may be retracted along withwires50 to enhance the distally-directed pushing force applied bytubes60 tolip region32. Continued retraction ofwires50 relative totubes60 would locklocks40 and fully deployapparatus10 withreplacement valve20 properly seated withinanchor30, as inFIGS. 1B and 2B.Apparatus10 comprises enhanced radial strength in the fully deployed configuration as compared to the partially deployed configuration ofFIG. 3A. Onceapparatus10 has been fully deployed,wires50 and62 may be removed fromapparatus10, thereby separatingdelivery system100 andtubes60 from the apparatus.
• Deployment ofapparatus10 is fully reversible untillocks40 have been actuated. For example, just prior to locking the position of the anchor and valve and the operation of the valve may be observed under fluoroscopy. If the position needs to be changed, by alternately relaxing and reapplying the proximally directed forces exerted bycontrol wires50 and/orcontrol wires62 and the distally directed forces exerted bytubes60, expansion and contraction of the lip and skirt regions ofanchor30 may be independently controlled so that the anchor and valve can be moved to, e.g., avoid blocking the coronary ostia or impinging on the mitral valve.Apparatus10 may also be completely retrieved withinlumen112 ofsheath110 by simultaneously proximally retractingwires50 andtubes60/wires62 relative tosheath110.Apparatus10 then may be removed from the patient or repositioned for subsequent redeployment.
• Referring now toFIG. 4, step-by-step deployment ofapparatus10 viadelivery system100 is described. InFIG. 4A,sheath110 is retracted relative toapparatus10,wires50 andtubes60, thereby causing self-expandable anchor30 to dynamically self-expandapparatus10 from the collapsed delivery configuration withinlumen112 ofsheath110 to the partially deployed configuration.Apparatus10 may then be dynamically repositioned viatubes60 to properly orient the apparatus, e.g. relative to a patient's native valve leaflets.
• InFIG. 4B,control wires50 are retracted whiletubes60 are advanced, thereby urginglip region32 ofanchor30 in a distal direction while urgingposts38 of the anchor in a proximal direction. This foreshortensapparatus10, as seen inFIG. 4C. Deployment ofapparatus10 is fully reversible even after foreshortening has been initiated and has advanced to the point illustrated inFIG. 4C.
• InFIG. 4D, continued foreshortening causes male interlockingelements44 oflocks40 to engagefemale interlocking elements42. The male elements mate with the female elements, thereby lockingapparatus10 in the foreshortened configuration, as seen inFIG. 4E.Wires50 are then pulled througheyelets45 ofmale elements44 to remove the wires fromapparatus10, andwires62 are pulled through the proximal end ofanchor30 to uncoupletubes60 from the apparatus, thereby separatingdelivery system100 fromapparatus10. Fully deployedapparatus10 is shown inFIG. 4F.
• Referring toFIG. 5, a method of endovascularly replacing a patient's diseased aortic valve withapparatus10 anddelivery system100 is described. As seen inFIG. 5A,sheath110 ofdelivery system100, havingapparatus10 disposed therein, is endovascularly advanced over guide wire G, preferably in a retrograde fashion (although an antegrade or hybrid approach alternatively may be used), through a patient's aorta A to the patient's diseased aortic valve AV. Anosecone102 precedessheath110 in a known manner. InFIG. 5B,sheath110 is positioned such that its distal region is disposed within left ventricle LV of the patient's heart H.
• Apparatus10 is deployed fromlumen112 ofsheath110, for example, under fluoroscopic guidance, such thatanchor30 ofapparatus10 dynamically self-expands to a partially deployed configuration, as inFIG. 5C. Advantageously,apparatus10 may be retracted withinlumen112 ofsheath110 viawires50—even afteranchor30 has dynamically expanded to the partially deployed configuration, for example, to abort the procedure or to repositionapparatus10 ordelivery system100. As yet another advantage,apparatus10 may be dynamically repositioned, e.g. viasheath110 and/ortubes60, in order to properly align the apparatus relative to anatomical landmarks, such as the patient's coronary ostia or the patient's native valve leaflets L. When properly aligned,skirt region34 ofanchor30 preferably is disposed distal of the leaflets, whilebody region36 is disposed across the leaflets andlip region32 is disposed proximal of the leaflets.
• Once properly aligned,wires50 are retracted relative totubes60 to impose foreshortening uponanchor30 and expandapparatus10 to the fully deployed configuration, as inFIG. 5D. Foreshortening increases the radial strength ofanchor30 to ensure prolonged patency of valve annulus An, as well as to provide a better seal forapparatus10 that reduces paravalvular regurgitation. As seen inFIG. 5E, locks40 maintain imposed foreshortening.Replacement valve20 is properly seated withinanchor30, and normal blood flow between left ventricle LV and aorta A is thereafter regulated byapparatus10. Deployment ofapparatus10 advantageously is fully reversible untillocks40 have been actuated.
• As seen inFIG. 5F,wires50 are pulled fromeyelets45 ofmale elements44 oflocks40,tubes60 are decoupled fromanchor30, e.g. viawires62, anddelivery system100 is removed from the patient, thereby completing deployment ofapparatus10.Optional barb elements37 engage the patient's native valve leaflets, e.g. to preclude migration of the apparatus and/or reduce paravalvular regurgitation.
• With reference now toFIG. 6, a method of endovascularly replacing a patient's diseased aortic valve withapparatus10 is provided, wherein proper positioning of the apparatus is ensured via positive registration of a modified delivery system to the patient's native valve leaflets. InFIG. 6A, modifieddelivery system100′ deliversapparatus10 to diseased aortic valve AV withinsheath110. As seen inFIGS. 6B and 6C,apparatus10 is deployed fromlumen112 ofsheath110, for example, under fluoroscopic guidance, such thatanchor30 ofapparatus10 dynamically self-expands to a partially deployed configuration. As when deployed viadelivery system100, deployment ofapparatus10 viadelivery system100′ is fully reversible untillocks40 have been actuated.
• Delivery system100′ comprisesleaflet engagement element120, which preferably self-expands along withanchor30.Engagement element120 is disposed betweentubes60 ofdelivery system100′ andlip region32 ofanchor30.Element120 releasably engages the anchor. As seen inFIG. 6C, the element is initially deployed proximal of the patient's native valveleaflets L. Apparatus10 andelement120 then may be advanced/dynamically repositioned until engagement element positively registers against the leaflets, thereby ensuring proper positioning ofapparatus10. Alsodelivery system100′ includes filter structure61A (e.g., filter membrane or braid) as part ofpush tubes60 to act as an embolic protection element. Emboli can be generated during manipulation and placement of anchor from either diseased native leaflet or surrounding aortic tissue and can cause blockage. Arrows61B inFIG. 6E show blood flow through filter structure61A where blood is allowed to flow but emboli is trapped in the delivery system and removed with it at the end of the procedure.
• Alternatively, foreshortening may be imposed uponanchor30 whileelement120 is disposed proximal of the leaflets, as inFIG. 6D. Upon positive registration ofelement120 against leaflets L,element120 precludes further distal migration ofapparatus10 during additional foreshortening, thereby reducing a risk of improperly positioning the apparatus.FIG. 6E details engagement ofelement120 against the native leaflets. As seen inFIG. 6F, onceapparatus10 is fully deployed,element120,wires50 andtubes60 are decoupled from the apparatus, anddelivery system100′ is removed from the patient, thereby completing the procedure.
• With reference toFIG. 7, an alternative embodiment of the apparatus ofFIG. 6 is described, whereinleaflet engagement element120 is coupled to anchor30 ofapparatus10′, rather than todelivery system100.Engagement element120 remains implanted in the patient post-deployment ofapparatus10′. Leaflets L are sandwiched betweenlip region32 ofanchor30 andelement120 in the fully deployed configuration. In this manner,element120 positively registersapparatus10′ relative to the leaflets and precludes distal migration of the apparatus over time.
• Referring now toFIG. 8, an alternative delivery system adapted for use with a balloon expandable embodiment of the present invention is described. InFIG. 8A,apparatus10″ comprisesanchor30′ that may be fabricated from balloon-expandable materials.Delivery system100″ comprisesinflatable member130 disposed in a deflated configuration withinlumen31 ofanchor30′. InFIG. 8B, optionalouter sheath110 is retracted, andinflatable member130 is inflated to expandanchor30′ to the fully deployed configuration. Asinflatable member130 is being deflated, as in earlier embodiments,wires50 and62 andtubes60 may be used to assist deployment ofanchor30′ and actuation oflocks40, as well as to provide reversibility and retrievability ofapparatus10″ prior to actuation oflocks40. Next,wires50 and62 andtubes60 are removed fromapparatus10″, anddelivery system100″ is removed, as seen inFIG. 8C.
• As an alternative delivery method,anchor30′ may be partially deployed via partial expansion ofinflatable member130. The inflatable member would then be advanced withinreplacement valve20 prior to inflation ofinflatable member130 and full deployment ofapparatus10″. Inflation pressures used will range from about 3 to 6 atm, or more preferably from about 4 to 5 atm, though higher and lower atm pressures may also be used (e.g., greater than 3 atm, more preferably greater than 4 atm, more preferably greater than 5 atm, or more preferably greater than 6 atm). Advantageously, separation ofinflatable member130 fromreplacement valve20, until partial deployment ofapparatus10″ at a treatment site, is expected to reduce a delivery profile of the apparatus, as compared to previously known apparatus. This profile reduction may facilitate retrograde delivery and deployment ofapparatus10″, even whenanchor30′ is balloon-expandable.
• Althoughanchor30′ has illustratively been described as fabricated from balloon-expandable materials, it should be understood thatanchor30′ alternatively may be fabricated from self-expanding materials whose expansion optionally may be balloon-assisted. In such a configuration,anchor30′ would expand to a partially deployed configuration upon removal ofouter sheath110. If required,inflatable member130 then would be advanced withinreplacement valve20 prior to inflation.Inflatable member130 would assist full deployment ofapparatus10″, for example, when the radial force required to overcome resistance from impinging tissue were too great to be overcome simply by manipulation ofwires50 andtubes60. Advantageously, optional placement ofinflatable member130 withinreplacement valve20, only after dynamic self-expansion ofapparatus10″ to the partially deployed configuration at a treatment site, is expected to reduce a delivery profile of the apparatus, as compared to previously known apparatus. This reduction may facilitate retrograde delivery and deployment ofapparatus10″.
• With reference toFIGS. 9 and 10, methods and apparatus for a balloon-assisted embodiment of the present invention are described in greater detail.FIGS. 9 and 10 illustratively showapparatus10′ ofFIG. 7 used in combination withdelivery system100″ ofFIG. 8.FIG. 10 illustrates a sectional view ofdelivery system100″.Inner shaft132 ofinflatable member130 preferably is about 4 Fr in diameter, and compriseslumen133 configured for passage of guidewire G, having a diameter of about 0.035″, therethrough. Pushtubes60 and pullwires50 pass throughguidetube140, which preferably has a diameter of about 15 Fr or smaller.Guide tube140 is disposed withinlumen112 ofouter sheath110, which preferably has a diameter of about 17 Fr or smaller.
• InFIG. 9A,apparatus10′ is delivered to diseased aortic valve AV withinlumen112 ofsheath110. InFIG. 9B,sheath110 is retracted relative toapparatus10′ to dynamically self-expand the apparatus to the partially deployed configuration. Also retracted and removed isnosecone102 which is attached to a pre-slit lumen (not shown) that facilitates its removal prior to loading and advancing of a regular angioplasty balloon catheter over guidewire and insidedelivery system110.
• InFIG. 9C, pullwires50 and pushtubes60 are manipulated from external to the patient to foreshortenanchor30 and sufficiently expandlumen31 of the anchor to facilitate advancement ofinflatable member130 withinreplacement valve20. Also shown is the tip of anangioplasty catheter130 being advanced throughdelivery system110.
• The angioplasty balloon catheter orinflatable member130 then is advanced within the replacement valve, as inFIG. 9D, and additional foreshortening is imposed uponanchor30 to actuatelocks40, as inFIG. 9E. The inflatable member is inflated to further displace the patient's native valve leaflets L and ensure adequate blood flow through, and long-term patency of,replacement valve20, as inFIG. 9F.Inflatable member130 then is deflated and removed from the patient, as inFIG. 9G. A different size angioplasty balloon catheter could be used repeat the same step if deemed necessary by the user. Pushtubes60 optionally may be used to further setleaflet engagement element120, or optional barbs B along posts38, more deeply within leaflets L, as inFIG. 9H. Then,delivery system100″ is removed from the patient, thereby completing percutaneous heart valve replacement.
• As will be apparent to those of skill in the art, the order of imposed foreshortening and balloon expansion described inFIGS. 9 and 10 is only provided for the sake of illustration. The actual order may vary according to the needs of a given patient and/or the preferences of a given medical practitioner. Furthermore, balloon-assist may not be required in all instances, and the inflatable member may act merely as a safety precaution employed selectively in challenging clinical cases.
• Referring now toFIG. 11, alternative locks for use with apparatus of the present invention are described. InFIG. 11A, lock40′ comprises male interlockingelement44 as described previously. However, female interlockingelement42′ illustratively comprises a triangular shape, as compared to the round shape of interlockingelement42 described previously. The triangular shape of female interlockingelement42′ may facilitate mating of male interlockingelement44 with the female interlocking element without necessitating deformation of the male interlocking element.
• InFIG. 11B, lock40″ comprises alternative male interlockingelement44′ having multiple in-line arrowheads46 along posts38. Each arrowhead comprises resilientlydeformable appendages48 to facilitate passage through female interlockingelement42.Appendages48 optionally compriseeyelets49, such thatcontrol wire50 or a secondary wire may pass therethrough to constrain the appendages in the deformed configuration. To actuatelock40″, one ormore arrowheads46 of male interlockingelement44′ are drawn through female interlockingelement42, and the wire is removed fromeyelets49, thereby causingappendages48 to resiliently expand and actuatelock40″.
• Advantageously, providingmultiple arrowheads46 alongposts38 yields a ratchet that facilitates in-vivo determination of a degree of foreshortening imposed upon apparatus of the present invention. Furthermore, optionally constrainingappendages48 ofarrowheads46 viaeyelets49 prevents actuation oflock40″ (and thus deployment of apparatus of the present invention) even aftermale element44′ has been advanced throughfemale element42. Only after a medical practitioner has removed thewire constraining appendages48 islock40″ fully engaged and deployment no longer reversible.
• Lock40′″ ofFIG. 11C is similar to lock40″ ofFIG. 11B, except thatoptional eyelets49 onappendages48 have been replaced byoptional overtube47.Overtube47 serves a similar function toeyelets49 by constrainingappendages48 to prevent locking until a medical practitioner has determined that apparatus of the present invention has been foreshortened and positioned adequately at a treatment site.Overtube47 is then removed, which causes the appendages to resiliently expand, thereby fully actuatinglock40′″.
• With reference toFIG. 12, an alternative locking mechanism is described that is configured to engage the patient's aorta. Male interlockingelements44″ oflocks40″ ″ comprisearrowheads46′ having sharpenedappendages48′. Upon expansion from the delivery configuration ofFIG. 12A to the foreshortened configuration ofFIG. 12B,apparatus10 positions sharpenedappendages48′ adjacent the patient'saorta A. Appendages48′ engage the aortic wall and reduce a risk of device migration over time.
• With reference now toFIG. 13, a risk of paravalvular leakage or regurgitation around apparatus of the present invention is described. InFIG. 13,apparatus10 has been implanted at the site of diseased aortic valve AV, for example, using techniques described hereinabove. The surface of native valve leaflets L is irregular, and interface I between leaflets L andanchor30 may comprise gaps where blood B may seep through. Such leakage poses a risk of blood clot formation or insufficient blood flow.
• Referring toFIG. 14, optional elements for reducing regurgitation or leakage are described.Compliant sacs200 may be disposed about the exterior ofanchor30 to provide a more efficient seal along irregularinterface I. Sacs200 may be filled with an appropriate material, for example, water, blood, foam or a hydrogel. Alternative fill materials will be apparent.
• With reference toFIG. 15, illustrative arrangements forsacs200 are provided. InFIG. 15A,sacs200 are provided as discrete sacs at different positions along the height ofanchor30. InFIG. 15B, the sacs are provided as continuous cylinders at various heights. InFIG. 15C, a single sac is provided with a cylindrical shape that spans multiple heights. The sacs ofFIG. 15D are discrete, smaller and provided in larger quantities.FIG. 15E provides a spiral sac. Alternative sac configurations will be apparent to those of skill in the art.
• With reference toFIG. 16, exemplary techniques for fabricatingsacs200 are provided. InFIG. 16A,sacs20 comprise ‘fish-scale’slots202 that may be back-filled, for example, with ambient blood passing throughreplacement valve20. InFIG. 16B, the sacs comprisepores204 that may be used to fill the sacs. InFIG. 16C, the sacs open to lumen31 ofanchor30 and are filled by blood washing past the sacs as the blood moves throughapparatus10.
• FIGS. 17 and 18 show yet another alternative embodiment of the anchor lock.Anchor300 has a plurality of male interlockingelements302 havingeyelets304 formed therein. Male interlocking elements are connected tobraided structure300 by inter-weaving elements302 (and308) or alternatively suturing, soldering, welding, or connecting with adhesive.Valve commissures24 are connected to male interlockingelements302 along their length.Replacement valve20annular base22 is connected to thedistal end34 of anchor300 (or30) as is illustrated inFIGS. 1A and 1B. Male interlockingelements302 also includeholes306 that mate withtabs310 extending intoholes312 infemale interlocking elements308. To lock,control wires314 passing througheyelets304 andholes312 are pulled proximally with respect to the proximal end ofbraided anchor300 to draw the male interlocking elements throughholes312 so thattabs310 engageholes306 in male interlockingelements302. Also shown isrelease wires314B that passes througheylet304B infemale interlocking element308. If needed, during the procedure, the user may pull onrelease wires314B reversing orientation oftabs310 releasing the anchor and allowing for repositioning of the device or it's removal from the patient. Only when final positioning as desired by the operating physician, would releasewire314B andcontrol wire314 are cut and removed from the patient with the delivery system.
• FIGS. 19-21 show an alternative way of releasing the connection between the anchor and its actuating tubes and control wires.Control wires62 extend throughtubes60 from outside the patient, loop through the proximal region ofanchor30 and extend partially back intotube60. The doubled up portion ofcontrol wire62 creates a force fit withintube60 that maintains the control wire's position with respect totube60 when allcontrol wires62 are pulled proximally to place a proximally directed force onanchor30. When asingle control wire62 is pulled proximally, however, the frictional fit between that control wire and the tube in which it is disposed is overcome, enabling theend63 ofcontrol wire62 to pull free of the tube, as shown inFIG. 21, thereby releasinganchor30.
• FIGS. 22-24 show an alternative embodiment of the anchor.Anchor350 is made of a metal braid, such as Nitinol or stainless steel. Areplacement valve354 is disposed withinanchor350.Anchor350 is actuated in substantially the same way asanchor30 ofFIGS. 1-4 through the application of proximally and distally directed forces from control wires (not shown) andtubes352.
• FIGS. 25 and 26 show yet another embodiment of the delivery and deployment apparatus of the invention. As an alternative to the balloon expansion method described with respect toFIG. 8, in this embodiment the nosecone (e.g.,element102 ofFIG. 5) is replaced by anangioplasty balloon catheter360. Thus,expandable balloon catheter360 precedessheath110 on guidewire G. Whenanchor30 andvalve20 are expanded through the operation oftubes60 and the control wires (not shown) as described above,balloon catheter360 is retracted proximally within the expanded anchor and valve and expanded further as described above with respect toFIG. 8.
• FIGS. 27-31show seals370 that expand over time to seal the interface between the anchor and valve and the patient's tissue.Seals370 are preferably formed from Nitinol wire surrounded by an expandable foam. As shown in cross-section inFIGS. 28 and 29, at the time of deployment, thefoam372 is compressed about thewire374 and held in the compressed form by a time-releasedcoating376. After deployment,coating376 dissolves in vivo to allowfoam372 to expand, as shown inFIGS. 30 and 31.
• FIGS. 32-34 show another way to seal the replacement valve against leakage. Afabric seal380 extends from the distal end ofvalve20 and back proximally overanchor30 during delivery. When deployed, as shown inFIGS. 33 and 34,fabric seal380 bunches up to create fabric flaps and pockets that extend into spaces formed by thenative valve leaflets382, particularly when the pockets are filled with blood in response to backflow blood pressure. This arrangement creates a seal around the replacement valve.
• FIGS.35A-H show another embodiment of a replacement heart valve apparatus in accordance with the present invention.Apparatus450 comprises replacement valve460 (seeFIGS. 37B and 38C) disposed within and coupled toanchor470.Replacement valve460 is preferably biologic, e.g. porcine, but alternatively may be synthetic.Anchor470 preferably is fabricated from self-expanding materials, such as a stainless steel wire mesh or a nickel-titanium alloy (“Nitinol”), and compriseslip region472,skirt region474, andbody regions476a,476band476c.Replacement valve460 preferably is coupled toskirt region474, but alternatively may be coupled to other regions of the anchor. As described hereinbelow,lip region472 andskirt region474 are configured to expand and engage/capture a patient's native valve leaflets, thereby providing positive registration, reducing paravalvular regurgitation, reducing device migration, etc.
• As seen inFIG. 35A,apparatus450 is collapsible to a delivery configuration, wherein the apparatus may be delivered viadelivery system410.Delivery system410 comprisessheath420 havinglumen422, as well aswires424aand424bseen inFIGS. 35D-35G.Wires424aare configured to expandskirt region474 ofanchor470, as well asreplacement valve460 coupled thereto, whilewires424bare configured to expandlip region472.
• As seen inFIG. 35B,apparatus450 may be delivered and deployed fromlumen422 ofcatheter420 while the apparatus is disposed in the collapsed delivery configuration. As seen inFIGS. 35B-35D,catheter420 is retracted relative toapparatus450, which causesanchor470 to dynamically self-expand to a partially deployed configuration.Wires424aare then retracted to expandskirt region474, as seen inFIGS. 35E and 35F. Preferably, such expansion may be maintained via locking features described hereinafter.
• InFIG. 35G,wires424bare retracted to expandlip region472 and fully deployapparatus450. As withskirt region474, expansion oflip region472 preferably may be maintained via locking features. After bothlip region472 andskirt region474 have been expanded, wires424 may be removed fromapparatus450, thereby separatingdelivery system410 from the apparatus.Delivery system410 then may be removed, as seen inFIG. 35H.
• As will be apparent to those of skill in the art,lip region472 optionally may be expanded prior to expansion ofskirt region474. As yet another alternative,lip region472 andskirt region474 optionally may be expanded simultaneously, in parallel, in a step-wise fashion or sequentially. Advantageously, delivery ofapparatus450 is fully reversible untillip region472 orskirt region474 has been locked in the expanded configuration.
• With reference now to FIGS.36A-E, individual cells ofanchor470 ofapparatus450 are described to detail deployment and expansion of the apparatus. InFIG. 36A, individual cells oflip region472,skirt region474 andbody regions476a,476band476care shown in the collapsed delivery configuration, as they would appear while disposed withinlumen422 ofsheath420 ofdelivery system410 ofFIG. 35. A portion of the cells forming body regions476, for example, every ‘nth’ row of cells, comprises locking features.
• Body region476acomprises male interlockingelement482 oflip lock480, whilebody region476bcomprisesfemale interlocking element484 oflip lock480.Male element482 compriseseyelet483.Wire424bpasses fromfemale interlocking element484 througheyelet483 and back throughfemale interlocking element484, such that there is a double strand ofwire424bthat passes throughlumen422 ofcatheter420 for manipulation by a medical practitioner external to the patient.Body region476bfurther comprises male interlockingelement492 ofskirt lock490, whilebody region476ccomprisesfemale interlocking element494 of the skirt lock.Wire424apasses fromfemale interlocking element494 througheyelet493 ofmale interlocking element492, and back throughfemale interlocking element494.Lip lock480 is configured to maintain expansion oflip region472, whileskirt lock490 is configured to maintain expansion ofskirt region474.
• InFIG. 36B,anchor470 is shown in the partially deployed configuration, e.g., after deployment fromlumen422 ofsheath420. Body regions476, as well aslip region472 andskirt region474, self-expand to the partially deployed configuration. Full deployment is then achieved by retracting wires424 relative to anchor470, and expandinglip region472 andskirt region474 outward, as seen inFIGS. 36C and 36D. As seen inFIG. 36E, expansion continues until the male elements engage the female interlocking elements oflip lock480 andskirt lock490, thereby maintaining such expansion (lip lock480 shown inFIG. 36E). Advantageously, deployment ofapparatus450 is fully reversible untillip lock480 and/orskirt lock490 has been actuated.
• With reference to FIGS.37A-B, isometric views, partially in section, further illustrateapparatus450 in the fully deployed and expanded configuration.FIG. 37A illustrates the wireframe structure ofanchor470, whileFIG. 37B illustrates an embodiment ofanchor470 covered in a biocompatible material B. Placement ofreplacement valve460 withinapparatus450 may be seen inFIG. 37B. The patient's native valve is captured betweenlip region472 andskirt region474 ofanchor470 in the fully deployed configuration (seeFIG. 38B).
• Referring to FIGS.38A-C, in conjunction withFIGS. 35 and 36, a method for endovascularly replacing a patient's diseased aortic valve withapparatus450 is described.Delivery system410, havingapparatus450 disposed therein, is endovascularly advanced, preferably in a retrograde fashion, through a patient's aorta A to the patient's diseased aortic valve AV.Sheath420 is positioned such that its distal end is disposed within left ventricle LV of the patient's heart H. As described with respect toFIG. 35,apparatus450 is deployed fromlumen422 ofsheath420, for example, under fluoroscopic guidance, such thatskirt section474 is disposed within left ventricle LV,body section476bis disposed across the patient's native valve leaflets L, andlip section472 is disposed within the patient's aorta A. Advantageously,apparatus450 may be dynamically repositioned to obtain proper alignment with the anatomical landmarks. Furthermore,apparatus450 may be retracted withinlumen422 ofsheath420 via wires424, even afteranchor470 has dynamically expanded to the partially deployed configuration, for example, to abort the procedure or to repositionsheath420.
• Once properly positioned,wires424aare retracted to expandskirt region474 ofanchor470 within left ventricle LV.Skirt region474 is locked in the expanded configuration viaskirt lock490, as previously described with respect toFIG. 36. InFIG. 38A,skirt region474 is maneuvered such that it engages the patient's valve annulus An and/or native valve leaflets L, thereby providing positive registration ofapparatus450 relative to the anatomical landmarks.
• Wires424bare then actuated external to the patient in order to expandlip region472, as previously described inFIG. 35.Lip region472 is locked in the expanded configuration vialip lock480. Advantageously, deployment ofapparatus450 is fully reversible untillip lock480 and/orskirt lock490 has been actuated. Wires424 are pulled fromeyelets483 and493, anddelivery system410 is removed from the patient. As will be apparent, the order of expansion oflip region472 andskirt region474 may be reversed, concurrent, etc.
• As seen inFIG. 38B,lip region472 engages the patient's native valve leaflets L, thereby providing additional positive registration and reducing a risk oflip region472 blocking the patient'scoronary ostia0.FIG. 38C illustrates the same in cross-sectional view, while also showing the position ofreplacement valve460. The patient's native leaflets are engaged and/or captured betweenlip region472 andskirt region474. Advantageously,lip region472 precludes distal migration ofapparatus450, whileskirt region474 precludes proximal migration. It is expected thatlip region472 andskirt region474 also will reduce paravalvular regurgitation.
• With reference toFIGS. 39-41, a first embodiment of two-piece apparatus of the present invention adapted for percutaneous replacement of a patient's heart valve is described. As seen inFIG. 41,apparatus510 comprises a two-piece device having custom-designedexpandable anchor piece550 ofFIG. 39 and expandablereplacement valve piece600 ofFIG. 40. Bothanchor piece550 andvalve piece600 have reduced delivery configurations and expanded deployed configurations. Both may be either balloon expandable (e.g. fabricated from a stainless steel) or self-expanding (e.g. fabricated from a nickel-titanium alloy (“Nitinol”) or from a wire mesh) from the delivery to the deployed configurations.
• When replacing a patient's aortic valve,apparatus510 preferably may be delivered through the patient's aorta without requiring a transseptal approach, thereby reducing patient trauma, complications and recovery time. Furthermore,apparatus510 enables dynamic repositioning ofanchor piece550 during delivery and facilitates positive registration ofapparatus510 relative to the native position of the patient's valve, thereby reducing a risk of device migration and reducing a risk of blocking or impeding flow to the patient's coronary ostia. Furthermore, the expanded deployed configuration ofapparatus510, as seen inFIG. 41D, is adapted to reduce paravalvular regurgitation, as well as to facilitate proper seating ofvalve piece600 withinanchor piece550.
• As seen inFIG. 39,anchor piece550 preferably comprises three sections.Lip section560 is adapted to engage the patient's native valve leaflets to provide positive registration and ensure accurate placement of the anchor relative to the patient's valve annulus during deployment, while allowing for dynamic repositioning of the anchor during deployment.Lip section560 also maintains proper positioning of composite anchor/valve apparatus510 post-deployment to preclude distal migration.Lip section560 optionally may be covered or coated with biocompatible film B (seeFIG. 41) to ensure engagement of the native valve leaflets. It is expected that coveringlip section560 with film B especially would be indicated when the native leaflets are stenosed and/or fused together.
• Groove section570 ofanchor piece550 is adapted to engage an expandable frame portion, described hereinbelow, ofvalve piece600 to coupleanchor piece550 tovalve piece600. As compared to previously known apparatus,groove section570 comprises additional material and reduced openings or gaps G, which is expected to reduce tissue protrusion through the gaps upon deployment, thereby facilitating proper seating of the valve within the anchor.Groove section570 optionally may be covered or coated with biocompatible film B (seeFIG. 41) to further reduce native valve tissue protrusion through gaps G.
• Finally,skirt section580 ofanchor piece550 maintains proper positioning of composite anchor/valve apparatus510 post-deployment by precluding proximal migration. When replacing a patient's aortic valve,skirt section580 is deployed within the patient's left ventricle. As withlip section560 andgroove section570,skirt section580 optionally may be covered or coated with biocompatible film B (seeFIG. 41) to reduce paravalvular regurgitation. As will be apparent to those of skill in the art, all, a portion of, or none ofanchor piece50 may be covered or coated with biocompatible film B.
• InFIG. 39A, a portion ofanchor piece550 has been flattened out to illustrate the basic anchor cell structure, as well as to illustrate techniques formanufacturing anchor piece550. In order to form the entire anchor,anchor550 would be bent at the locations indicated inFIG. 39A, and the basic anchor cell structure would be revolved to form a joined 360° structure.Lip section560 would be bent back into the page to form a lip that doubles over the groove section,groove section570 would be bent out of the page into a ‘C’- or ‘U’-shaped groove, whileskirt section580 would be bent back into the page.FIG. 39B shows the anchor portion after bending and in an expanded deployed configuration.
• The basic anchor cell structure seen inFIG. 39A is preferably formed through laser cutting of a flat sheet or of a hollow tube placed on a mandrel. When formed from a flat sheet, the sheet would be cut to the required number of anchor cells, bent to the proper shape, and revolved to form a cylinder. The ends of the cylinder would then be joined together, for example, by heat welding.
• If balloon expandable,anchor piece550 would be formed from an appropriate material, such as stainless steel, and then crimped onto a balloon delivery catheter in a collapsed delivery configuration. If self-expanding and formed from a shape-memory material, such as a nickel-titanium alloy (“Nitinol”), the anchor piece would be heat-set such that it could be constrained within a sheath in the collapsed delivery configuration, and then would dynamically self-expand to the expanded deployed configuration upon removal of the sheath. Likewise, ifanchor piece550 were formed from a wire mesh or braid, such as a spring steel braid, the anchor would be constrained within a sheath in the delivery configuration and dynamically expanded to the deployed configuration upon removal of the sheath.
• InFIG. 40,valve piece600 is described in greater detail.FIG. 40A illustratesvalve piece600 in a collapsed delivery configuration, whileFIG. 40B illustrates the valve piece in an expanded deployed configuration.Valve piece600 comprisesreplacement valve610 coupled toexpandable frame620.Replacement valve610 is preferably biologic, although synthetic valves may also be used.Replacement valve610 preferably comprises three leaflets611 coupled to threeposts621 ofexpandable frame620.Expandable frame620 is preferably formed from a continuous piece of material and may comprisetips622 in the collapsed delivery configuration, which expand to formhoop624 in the deployed configuration.Hoop624 is adapted to engagegroove section570 ofanchor piece550 forcoupling anchor piece550 tovalve piece600. As withanchor piece550,valve piece600 may be balloon expandable and coupled to a balloon delivery catheter in the delivery configuration. Alternatively,anchor piece550 may be self-expanding, e.g. Nitinol or wire mesh, and constrained within a sheath in the delivery configuration.
• Referring again toFIG. 41, a method for deployingvalve piece600 and coupling it to deployedanchor piece550 to form two-piece apparatus510 is described. InFIG. 41A,valve piece600 is advanced withinanchor piece550 in an at least partially compressed delivery configuration. InFIG. 41B,tips622 offrame620 are expanded such that they engagegroove section570 ofanchor piece550. InFIG. 41C,frame620 continues to expand andform hoop624.Hoop624 flares out from the remainder ofvalve piece600 and acts to properly locate the hoop withingroove section570.FIG. 41D showsvalve piece600 in a fully deployed configuration, properly seated and friction locked withingroove section570 to form composite anchor/valve apparatus510.
• Anchor piece550 andvalve piece600 ofapparatus510 preferably are spaced apart and releasably coupled to a single delivery catheter while disposed in their reduced delivery configurations. Spacing the anchor and valve apart reduces a delivery profile of the device, thereby enabling delivery through a patient's aorta without requiring a transseptal approach. With reference toFIG. 42, a first embodiment of singlecatheter delivery system700 for use withapparatus510 is described.Delivery system700 is adapted for use with a preferred self-expanding embodiment ofapparatus510.
• Delivery system700 comprisesdelivery catheter710 havinginner tube720, middledistal tube730, andouter tube740.Inner tube720 compriseslumen722 adapted for advancement over a standard guide wire, per se known. Middledistal tube730 is coaxially disposed about a distal region ofinner tube720 and is coupled to adistal end724 of the inner tube, thereby forming proximally-orientedannular bore732 betweeninner tube720 andmiddle tube730 at a distal region ofdelivery catheter710.Outer tube740 is coaxially disposed aboutinner tube720 and extends from a proximal region of the inner tube to a position at least partially coaxially overlapping middledistal tube730.Outer tube740 preferably comprisesdistal step742, whereinlumen743 ofouter tube740 is of increased diameter.Distal step742 may overlap middledistal tube730 and may also facilitate deployment ofvalve piece600, as described hereinbelow with respect toFIG. 45.
• Proximally-orientedannular bore732 betweeninner tube720 and middledistal tube730 is adapted to receiveskirt section580 andgroove section570 ofanchor piece550 in the reduced delivery configuration.Annular space744 formed at the overlap between middledistal tube730 andouter tube740 is adapted to receivelip section560 ofanchor piece550 in the reduced delivery configuration. More proximalannular space746 betweeninner tube720 andouter tube740 may be adapted to receivereplacement valve610 andexpandable frame620 ofvalve piece600 in the reduced delivery configuration.
• Inner tube720 optionally may compriseretainer elements726aand726bto reduce migration ofvalve piece600. Retainer elements726 preferably are fabricated from a radiopaque material, such as platinum-iridium or gold, to facilitate deployment ofvalve piece600, as well as coupling of the valve piece to anchorpiece550. Additional or alternative radiopaque elements may be disposed at other locations aboutdelivery system700 orapparatus510, for example, in the vicinity ofanchor piece550.
• With reference now toFIG. 43, an alternative delivery system for use with apparatus of the present invention is described.Delivery system750 comprises two distinct catheters adapted to deliver the anchor and valve pieces, respectively:anchor delivery catheter710′ andvalve delivery catheter760. In use,catheters710′ and760 may be advanced sequentially to a patient's diseased heart valve for sequential deployment and coupling ofanchor piece550 tovalve piece600 to form composite two-piece apparatus510.
• Delivery catheter710′ is substantially equivalent tocatheter710 described hereinabove, except thatcatheter710′ does not comprise retainer elements726, andannular space746 does not receivevalve piece600. Rather,valve piece600 is received withincatheter760 in the collapsed delivery configuration.Catheter760 comprises inner tube770 andouter tube780. Inner tube770 compriseslumen772 for advancement ofcatheter760 over a guide wire. The inner tube optionally may also comprise retainer elements774aand774b, e.g. radiopaque retainer elements774, to reduce migration ofvalve piece600.Outer tube780 is coaxially disposed about inner tuber770 and preferably comprisesdistal step782 to facilitate deployment and coupling ofvalve piece600 toanchor piece550, as described hereinbelow.Valve piece600 may be received in annular space776 between inner tube770 andouter tube780, and more preferably may be received within annular space776 between retainer elements774.
• Referring now toFIG. 44, another alternative delivery system is described. As discussed previously, eitheranchor piece550 or valve piece600 (or portions thereof or both) may be balloon expandable from the delivery configuration to the deployed configuration.Delivery system800 is adapted for delivery of an embodiment ofapparatus510 wherein the valve piece is balloon expandable. Additional delivery systems—both single and multi-catheter—for deployment of alternative combinations of balloon and self-expandable elements of apparatus of the present invention will be apparent to those of skill in the art in view of the illustrative delivery systems provided inFIGS. 42-44.
• InFIG. 44,delivery system800 comprisesdelivery catheter710″.Delivery catheter710″ is substantially equivalent todelivery catheter710 ofdelivery system700, except thatcatheter710″ does not comprise retainer elements726, andannular space746 does not receive the valve piece. Additionally,catheter710″ comprisesinflatable balloon802 coupled to the exterior ofouter tube740″, as well as an inflation lumen (not shown) for reversibly delivering an inflation medium from a proximal region ofcatheter710″ into the interior ofinflatable balloon802 for expanding the balloon from a delivery configuration to a deployed configuration.Valve piece600 may be crimped to the exterior ofballoon802 in the delivery configuration, then deployed and coupled toanchor piece550 in vivo.Delivery catheter710″ preferably comprises radiopaque marker bands804aand804bdisposed on either side ofballoon802 to facilitate proper positioning ofvalve piece600 during deployment of the valve piece, for example, under fluoroscopic guidance.
• With reference now toFIG. 45, in conjunction withFIGS. 39-42, an illustrative method of endovascularly replacing a patient's diseased heart valve using apparatus of the present invention is described. InFIG. 45A, a distal region ofdelivery system700 ofFIG. 42 has been delivered through a patient's aorta A, e.g., over a guide wire and under fluoroscopic guidance using well-known percutaneous techniques, to a vicinity of diseased aortic valve AV ofheart H. Apparatus510 ofFIGS. 39-41 is disposed in the collapsed delivery configuration withindelivery catheter710 withgroove section570 andskirt section580 ofanchor piece550 collapsed withinannular bore732, andlip section560 ofanchor piece550 collapsed withinannular space744.Valve piece600 is disposed in the collapsed delivery configuration between retainer elements726 within more proximalannular space746. Separation ofanchor piece550 andvalve piece600 ofapparatus510 along the longitudinal axis ofdelivery catheter710 enables percutaneous aortic delivery ofapparatus510 without requiring a transseptal approach.
• Aortic valve AV comprises native valve leaflets L attached to valve annulus An. Coronary ostia O are disposed just proximal of diseased aortic valve AV. Coronary ostia O connect the patient's coronary arteries to aorta A and are the conduits through which the patient's heart muscle receives oxygenated blood. As such, it is critical that the ostia remain unobstructed post-deployment ofapparatus510.
• InFIG. 45A, a distal end ofdelivery catheter710 has been delivered across diseased aortic valve AV into the patient's left ventricle LV. As seen inFIG. 45B,outer tube740 is then retracted proximally relative toinner tube720 and middledistal tube730.Outer tube740 no longer coaxially overlaps middledistal tube730, andlip section560 ofanchor piece550 is removed fromannular space744.Lip section560 self-expands to the deployed configuration. As seen inFIG. 45C,inner tube720 and middle tube730 (or all of delivery catheter710) are then distally advanced untillip section560 engages the patient's native valve leaflets L, thereby providing positive registration ofanchor piece550 to leaflets L. Registration may be confirmed, for example, via fluoroscopic imaging of radiopaque features coupled toapparatus510 ordelivery system700 and/or via resistance encountered by the medical practitioner distally advancinganchor piece550.
• Lip section560 may be dynamically repositioned until it properly engages the valve leaflets, thereby ensuring proper positioning ofanchor piece550 relative to the nativecoronary ostia0, as well as the valve annulus An, prior to deployment ofgroove section570 andskirt section580. Such multi-step deployment ofanchor piece550 enables positive registration and dynamic repositioning of the anchor piece. This is in contrast to previously known percutaneous valve replacement apparatus.
• As seen inFIG. 45D, once leaflets L have been engaged bylip section560 ofanchor piece550,inner tube720 and middledistal tube730 are further distally advanced within left ventricle LV, whileouter tube740 remains substantially stationary.Lip section560, engaged by leaflets L, precludes further distal advancement/migration ofanchor piece550. As such,groove section570 andskirt section580 are pulled out of proximally-orientedannular bore732 betweeninner tube720 and middledistal tube730 when the tubes are distally advanced. The groove and skirt sections self-expand to the deployed configuration, as seen inFIG. 45E.Groove section570 pushes native valve leaflets L andlip section560 against valve annulus An, whileskirt section580 seals against an interior wall of left ventricle LV, thereby reducing paravalvular regurgitation across aortic valve AV and precluding proximal migration ofanchor piece550.
• Withanchor piece550 deployed and native aortic valve AV displaced,valve piece600 may be deployed and coupled to the anchor piece to achieve percutaneous aortic valve replacement.Outer tube740 is further proximally retracted relative toinner tube720 such thatvalve piece600 is partially deployed fromannular space746 betweeninner tube720 andouter tube740, as seen inFIG. 45F.Expandable frame620 coupled toreplacement valve610 partially self-expands such thattips622 partially formhoop624 for engagement ofgroove section570 of anchor piece550 (seeFIG. 41B). A proximal end ofexpandable frame620 is engaged bydistal step742 ofouter tube740.
• Subsequent re-advancement ofouter tube740 relative toinner tube720 causesdistal step742 to distallyadvance valve piece600 withinanchor piece550 untiltips622 ofexpandable frame620 engagegroove section570 ofanchor piece550, as seen inFIG. 45G. As discussed previously,groove section570 comprises additional material and reduced openings or gaps G, as compared to previously known apparatus, which is expected to reduce native valve tissue protrusion through the gaps and facilitate engagement oftips622 with the groove section.Outer tube740 then is proximally retracted again relative toinner tube720, andvalve piece600 is completely freed fromannular space746.Frame620 ofvalve piece600 fully expands to formhoop624, as seen inFIG. 45H.
• Hoop624 friction locks withingroove section570 ofanchor piece550, thereby coupling the anchor piece to the valve piece and forming composite two-piece apparatus510, which provides a percutaneous valve replacement. As seen inFIG. 451,delivery catheter710 may then be removed from the patient, completing the procedure. Blood may freely flow from left ventricle LV throughreplacement valve610 into aorta A. Coronary ostia0 are unobstructed, and paravalvular regurgitation is reduced byskirt section580 ofanchor piece550.
• Referring now toFIG. 46, an alternative embodiment of two-piece apparatus510 is described comprising an alignment/locking mechanism. Such a mechanism may be provided in order to ensure proper radial alignment of the expandable frame of the valve piece with the groove section of the anchor piece, as well as to ensure proper longitudinal positioning of the frame within the hoop. Additionally, the alignment/locking mechanism may provide a secondary lock to further reduce a risk of the anchor piece and the valve piece becoming separated post-deployment and coupling of the two pieces to achieve percutaneous valve replacement.
• InFIG. 46,apparatus510′ comprisesvalve piece600′ ofFIG. 46A andanchor piece550′ ofFIG. 46B.Anchor piece550′ andvalve piece600′ are substantially the same asanchor piece550 andvalve piece600 described hereinabove, except thatanchor piece550′ comprisesfirst portion652 of illustrative alignment/locking mechanism650, whilevalve piece600′ comprisessecond portion654 of the alignment/locking mechanism for coupling to the first portion.First portion652 illustratively comprises threeguideposts653 coupled toskirt section580′ ofanchor piece550′ (only one guidepost shown in the partial view ofFIG. 46B), whilesecond portion654 comprises threesleeves655 coupled toposts621′ ofexpandable frame620′ ofvalve piece600′.
• Whenanchor piece550′ is self-expanding and collapsed in the delivery configuration,guideposts653 may be deployed withskirt section580′, in which case guideposts653 would rotate upward with respect toanchor piece550′ into the deployed configuration ofFIG. 46B. Alternatively, whenanchor piece550′ is either balloon or self-expanding and is collapsed in the delivery configuration,guideposts653 may be collapsed againstgroove section570′ of the anchor piece and may be deployed with the groove section. Deployingguideposts653 withskirt section580′ has the advantages of reduced delivery profile and ease of manufacturing, but has the disadvantage of significant dynamic motion during deployment. Conversely, deployingguideposts653 withgroove section570′ has the advantage of minimal dynamic motion during deployment, but has the disadvantage of increased delivery profile. Additional deployment configurations will be apparent to those of skill in the art. As will also be apparent,first portion652 of alignment/locking mechanism650 may be coupled to alternative sections ofanchor piece550′ other thanskirt section580′.
• Sleeves655 ofsecond portion654 of alignment/locking mechanism650 compriselumens656 sized for coaxial disposal ofsleeves655 aboutguideposts653 offirst portion652. Upon deployment,sleeves655 may friction lock toguideposts653 to ensure proper radial and longitudinal alignment ofanchor piece550′ withvalve piece600′, as well as to provide a secondary lock of the anchor piece to the valve piece. The secondary lock enhances the primary friction lock formed bygroove section570′ of the anchor piece withhoop624′ ofexpandable frame620′ of the valve piece.
• To facilitate coupling of the anchor piece to the valve piece, suture or thread may pass from optional eyelets651aofguideposts653 throughlumens656 ofsleeves655 to a proximal end of the delivery catheter (seeFIG. 47). In this manner,second portion654 ofmechanism650 may be urged into alignment withfirst portion652, and optional suture knots (not shown), e.g. pre-tied suture knots, may be advanced on top of the mechanism post-coupling of the two portions to lock the two portions together. Alternatively,guideposts653 may comprise optional one-way valves651bto facilitate coupling of the first portion to the second portion. Specifically,sleeves655 may be adapted for coaxial advancement over one-way valves651bin a first direction that couples the sleeves toguideposts653, but not in a reverse direction that would uncouple the sleeves from the guideposts.
• Referring now toFIG. 47, an alternative embodiment ofapparatus510′ comprising an alternative alignment/locking mechanism is described.Apparatus510″ is illustratively shown in conjunction withdelivery system700 described hereinabove with respect toFIG. 42.Valve piece600″ is shown partially deployed fromouter tube740 ofcatheter710. For the sake of illustration,replacement valve610″ ofvalve piece600″, as well asinner tube720 and middledistal tube730 ofdelivery catheter710, are not shown inFIG. 47.
• InFIG. 47,anchor piece550″ ofapparatus510″ comprisesfirst portion652′ of alignment/locking mechanism650′, whilevalve piece600″ comprisessecond portion654′ of the alternative alignment/locking mechanism.First portion652′ compriseseyelets660 coupled togroove section570″ ofanchor piece550″.Second portion654′ comprises knotted loops of suture662 coupled totips622″ ofexpandable frame620″ ofvalve piece600″.Suture661 extends from knotted loops of suture662 througheyelets660 and out throughannular space746 betweenouter tube740 and inner tube720 (seeFIG. 42) ofcatheter710 to a proximal end ofdelivery system700. In this manner, a medical practitioner may radially and longitudinally alignvalve piece600″ withanchor piece550″ by proximally retracting sutures661 (as shown by arrows inFIG. 47) while distally advancingdistal step742 ofouter tube740 againstvalve piece600″ untiltips622″ of the valve piece engagegroove section570″ ofanchor piece550″. Proximal retraction ofouter tube740 then causesexpandable frame620″ to further expand andform hoop624″ that friction locks withgroove section570″ ofanchor piece550″, thereby formingapparatus510″ as described hereinabove with respect toapparatus510. A secondary lock may be achieved by advancing optional suture knots (not shown) to the overlap ofeyelets660 and knotted loops of suture662. Such optional suture knots preferably are pre-tied.
• With reference now toFIG. 48, yet another alternative embodiment ofapparatus510′, comprising yet another alternative alignment/locking mechanism650, is described.First portion652″ of alignment/locking mechanism650″ is coupled to anchorpiece550′″ ofapparatus510′″, whilesecond portion654″ is coupled tovalve piece600′″. The first portion comprisesmale posts670 having flared ends671, while the second portion comprisesfemale guides672 coupled totips622′″ ofexpandable frame620′″ ofvalve piece600′″.
• Female guides672 are translatable aboutmale posts670, but are constrained by flared ends671 of the male posts. In this manner,anchor piece550′″ andvalve piece600′″ remain coupled and in radial alignment with one another at all times—including delivery—but may be longitudinally separated from one another during delivery. This facilitates percutaneous delivery without requiring a transseptal approach, while mitigating a risk of inadvertent deployment of the anchor and valve pieces in an uncoupled configuration. Additional alignment/locking mechanisms will be apparent in view of the mechanisms described with respect toFIGS. 46-48.
• Prior to implantation of one of the replacement valves described above, it may be desirable to perform a valvoplasty on the diseased valve by inserting a balloon into the valve and expanding it using saline mixed with a contrast agent. In addition to preparing the valve site for implant, fluoroscopic viewing of the valvoplasty will help determine the appropriate size of replacement valve implant to use.

Claims (18)

1. Apparatus for endovascularly replacing a patient's heart valve, the apparatus comprising:

an expandable anchor comprising a lip region and a skirt region; and

a replacement valve,

wherein the lip region and skirt region are configured for percutaneous expansion to engage leaflets of the heart valve.

2. The apparatus ofclaim 1 wherein the lip region and skirt region are configured for independent expansion.

3. The apparatus ofclaim 1 wherein the lip region and skirt region are configured for concurrent expansion.

4. The apparatus ofclaim 1 wherein the lip region is adapted to preclude distal migration of the apparatus post-deployment and expansion.

5. The apparatus ofclaim 1 wherein the skirt section is adapted to preclude proximal migration of the apparatus post-deployment and expansion.

6. The apparatus ofclaim 1 wherein the anchor is at least partially covered by a biocompatible film.

7. The apparatus ofclaim 1 wherein the replacement valve is configured to be coupled to the anchor during percutaneous delivery.

8. The apparatus ofclaim 1 wherein the anchor and the replacement valve are adapted for expansion from the delivery to the deployed configurations via a mechanism chosen from the group consisting of balloon-expansion, self-expansion, and combinations thereof.

9. The apparatus ofclaim 1 further comprising a delivery system configured for percutaneous advancement of the apparatus to a vicinity of the patient's diseased valve while the anchor is disposed in a collapsed delivery configuration.

10. The apparatus ofclaim 9 wherein the delivery system facilitates deployment and expansion of the apparatus to endovascularly replace the heart valve.

11. The apparatus ofclaim 10 wherein the delivery system is configured to retrieve the apparatus.

12. The apparatus ofclaim 1 further comprising at least one locking element configured to maintain expansion of the lip region and the skirt region.

13. A method for endovascularly replacing a patient's heart valve, the method comprising:

endovascularly delivering apparatus comprising an anchor having lip and skirt regions, and a replacement valve coupled to the anchor, to a vicinity of the heart valve in a collapsed delivery configuration;

expanding the apparatus such that leaflets of the heart valve are captured between the lip and skirt regions of the anchor.

14. The method ofclaim 13, wherein expanding the apparatus further comprises dynamically repositioning the apparatus relative to the heart valve prior to capturing the leaflets.

15. The method ofclaim 13, wherein expanding the apparatus further comprises expanding either the lip region or the skirt region, positively engaging the heart valve with the expanded lip or skirt region, and then expanding the unexpanded region.

16. The method ofclaim 13 wherein expanding the apparatus further comprises retrieving the apparatus, repositioning the apparatus, and redeploying the apparatus.

17. The method ofclaim 13 further comprising locking the apparatus in the expanded configuration.

18. The method ofclaim 13, wherein capturing the leaflets further comprises precluding proximal and distal migration of the apparatus relative to the patient's diseased valve.

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