Methods and devices for delivery of prosthetic heart valves and other prosthetics

Prosthetic valves and their component parts are described, as are prosthetic valve delivery devices and methods for their use. The prosthetic valves are particularly adapted for use in percutaneous aortic valve replacement procedures. The delivery devices are particularly adapted for use in minimally invasive surgical procedures. The preferred delivery device includes a catheter having a deployment mechanism attached to its distal end, and a handle mechanism attached to its proximal end. A plurality of tethers are provided to selectively restrain the valve during deployment. A number of mechanisms for active deployment of partially expanded prosthetic valves are also described.

CROSS REFERENCES TO RELATED APPLICATIONS

This application relates to U.S. patent application Ser. No. 11/066,126, entitled “Prosthetic Heart Valves, Scaffolding Structures, and Methods for Implantation of Same,” filed Feb. 25, 2005, which application is hereby incorporated by reference in its entirety. The foregoing application claims the benefit of U.S. Provisional Application Ser. No. 60/548,731, entitled “Foldable Stent for Minimally Invasive Surgery,” filed Feb. 27, 2004, and U.S. Provisional Application Ser. No. 60/559,199, entitled “Method and Multiple Balloon for Percutaneous Aortic Valve Implantation,” filed Apr. 1, 2004, each of which applications is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and methods. More particularly, the present invention relates to methods and devices for delivering and deploying prosthetic heart valves and similar structures using minimally invasive surgical methods.

BACKGROUND OF THE INVENTION

Diseases and other disorders of the heart valve affect the proper flow of blood from the heart. Two categories of heart valve disease are stenosis and incompetence. Stenosis refers to a failure of the valve to open fully, due to stiffened valve tissue. Incompetence refers to valves that cause inefficient blood circulation by permitting backflow of blood in the heart.

Medication may be used to treat some heart valve disorders, but many cases require replacement of the native valve with a prosthetic heart valve. Prosthetic heart valves can be used to replace any of the native heart valves (aortic, mitral, tricuspid or pulmonary), although repair or replacement of the aortic or mitral valves is most common because they reside in the left side of the heart where pressures are the greatest. Two primary types of prosthetic heart valves are commonly used, mechanical heart valves and prosthetic tissue heart valves.

The caged ball design is one of the early mechanical heart valves. The caged ball design uses a small ball that is held in place by a welded metal cage. In the mid-1960s, another prosthetic valve was designed that used a tilting disc to better mimic the natural patterns of blood flow. The tilting-disc valves had a polymer disc held in place by two welded struts. The bileaflet valve was introduced in the late 1970s. It included two semicircular leaflets that pivot on hinges. The leaflets swing open completely, parallel to the direction of the blood flow. They do not close completely, which allows some backflow.

The main advantages of mechanical valves are their high durability. Mechanical heart valves are placed in young patients because they typically last for the lifetime of the patient. The main problem with all mechanical valves is the increased risk of blood clotting.

Prosthetic tissue valves include human tissue valves and animal tissue valves. Both types are often referred to as bioprosthetic valves. The design of bioprosthetic valves are closer to the design of the natural valve. Bioprosthetic valves do not require long-term anticoagulants, have better hemodynamics, do not cause damage to blood cells, and do not suffer from many of the structural problems experienced by the mechanical heart valves.

Human tissue valves include homografts, which are valves that are transplanted from another human being, and autografts, which are valves that are transplanted from one position to another within the same person.

Animal tissue valves are most often heart tissues recovered from animals. The recovered tissues are typically stiffened by a tanning solution, most often glutaraldehyde. The most commonly used animal tissues are porcine, bovine, and equine pericardial tissue.

The animal tissue valves are typically stented valves. Stentless valves are made by removing the entire aortic root and adjacent aorta as a block, usually from a pig. The coronary arteries are tied off, and the entire section is trimmed and then implanted into the patient.

A conventional heart valve replacement surgery involves accessing the heart in the patent's thoracic cavity through a longitudinal incision in the chest. For example, a median sternotomy requires cutting through the sternum and forcing the two opposing halves of the rib cage to be spread apart, allowing access to the thoracic cavity and heart within. The patient is then placed on cardiopulmonary bypass which involves stopping the heart to permit access to the internal chambers. Such open heart surgery is particularly invasive and involves a lengthy and difficult recovery period.

A less invasive approach to valve replacement is desired. The percutaneous implantation of a prosthetic valve is a preferred procedure because the operation is performed under local anesthesia, does not require cardiopulmonary bypass, and is less traumatic. Current attempts to provide such a device generally involve stent-like structures, which are very similar to those used in vascular stent procedures with the exception of being larger diameter as required for the aortic anatomy, as well as having leaflets attached to provide one way blood flow. These stent structures are radially contracted for delivery to the intended site, and then expanded/deployed to achieve a tubular structure in the annulus. The stent structure needs to provide two primary functions. First, the structure needs to provide adequate radial stiffness when in the expanded state. Radial stiffness is required to maintain the cylindrical shape of the structure, which assures the leaflets coapt properly. Proper leaflet coaption assures the edges of the leaflets mate properly, which is necessary for proper sealing without leaks. Radial stiffness also assures that there will be no paravalvular leakage, which is leaking between the valve and aorta interface, rather than through the leaflets. An additional need for radial stiffness is to provide sufficient interaction between the valve and native aortic wall that there will be no valve migration as the valve closes and holds full body blood pressure. This is a requirement that other vascular devices are not subjected to. The second primary function of the stent structure is the ability to be crimped to a reduced size for implantation.

Prior devices have utilized traditional stenting designs which are produced from tubing or wire wound structures. Although this type of design can provide for crimpability, it provides little radial stiffness. These devices are subject to “radial recoil” in that when the device is deployed, typically with balloon expansion, the final deployed diameter is smaller than the diameter the balloon and stent structure were expanded to. The recoil is due in part because of the stiffness mismatches between the device and the anatomical environment in which it is placed. These devices also commonly cause crushing, tearing, or other deformation to the valve leaflets during the contraction and expansion procedures. Other stenting designs have included spirally wound metallic sheets. This type of design provides high radial stiffness, yet crimping results in large material strains that can cause stress fractures and extremely large amounts of stored energy in the constrained state. Replacement heart valves are expected to survive for many years when implanted. A heart valve sees approximately 500,000,000 cycles over the course of 15 years. High stress states during crimping can reduce the fatigue life of the device. Still other devices have included tubing, wire wound structures, or spirally wound sheets formed of nitinol or other superelastic or shape memory material. These devices suffer from some of the same deficiencies as those described above.

A number of improved prosthetic heart valves and scaffolding structures are described in co-pending U.S. patent application Ser. No. 11/066,126, entitled “Prosthetic Heart Valves, Scaffolding Structures, and Methods for Implantation of Same,” filed Feb. 25, 2005, (“the '126 application”) which application is hereby incorporated by reference in its entirety. Several of the prosthetic heart valves described in the '126 application include a support member having a valvular body attached, the support member preferably comprising a structure having three panels separated by three foldable junctions. The '126 application also describes several delivery mechanisms adapted to deliver the described prosthetic heart valve. Although the prosthetic heart valves and delivery systems described in the '126 application represent a substantial advance in the art, additional delivery systems and methods are desired, particularly such systems and methods that are adapted to deliver and deploy the prosthetic heart valves described therein.

SUMMARY OF THE INVENTION

The present invention provides methods and devices for deploying prosthetic heart valves and other prosthetic devices in body lumens. The methods and devices are particularly adapted for use in percutaneous aortic valve replacement. The methods and devices may also find use in the peripheral vasculature, the abdominal vasculature, and in other ducts such as the biliary duct, the fallopian tubes, and similar lumen structures within the body of a patient. Although particularly adapted for use in lumens found in the human body, the apparatus and methods may also find application in the treatment of animals.

Without intending to limit the scope of the methods and devices described herein, the deployment devices and methods are particularly adapted for delivery of prosthetic heart valves and scaffolding structures identical or similar to those described in the '126 application described above. A particularly preferred prosthetic heart valve includes a generally cylindrical support structure formed of three segments, such as panels, interconnected by three foldable junctions, such as hinges, a representative embodiment of which is illustrated in FIG. 1A of the '126 application, which is reproduced herein asFIG. 1A. The exemplary prosthetic valve30includes a generally cylindrical support member32made up of three generally identical curved panels36and a valvular body34attached to the internal surface of the support member. Each panel includes an aperture40through which extends a plurality of interconnecting braces42that define a number of sub-apertures44,46,48,50. A hinge52is formed at the junction formed between each pair of adjacent panels. The hinge may be a membrane hinge comprising a thin sheet of elastomeric material54attached to the external edge56of each of a pair of adjacent panels36.

Turning toFIG. 1B-C, a method for transforming a prosthetic valve from its expanded state to its contracted state is illustrated. These Figures show a three-panel support member without a valvular body attached. The method for contracting a full prosthetic valve, including the attached valvular body, is similar to that described herein in relation to the support member alone. As shown inFIG. 1B, each of the panels36is first inverted, by which is meant that a longitudinal centerline80of each of the panels36is forced radially inward toward the central longitudinal axis82of the support member. This action is facilitated by having panels formed of a thin, resilient sheet of material having generally elastic properties, and by the presence of the hinges52located at the junction between each pair of adjacent panels36. During the inversion step, the edges56of each of the adjacent pairs of panels fold upon one another at the hinge52. The resulting structure, shown inFIG. 1B, is a three-vertex58star shaped structure, referred to herein as a “tri-star” shape. Those skilled in the art will recognize that a similar procedure may be used to invert a four (or more) panel support member, in which case the resulting structure would be a four- (or more) vertex star shaped structure.

The prosthetic valve30may be further contracted by curling each of the vertices58of the star shaped structure to form a multi-lobe structure, as shown inFIG. 1C. As shown in that Figure, each of the three vertices58is rotated toward the center longitudinal axis82of the device, causing each of the three folded-upon edges of the adjacent pairs of panels to curl into a lobe84. The resulting structure, illustrated inFIG. 1C, is a “tri-lobe” structure that represents the fully contracted state of the prosthetic valve. Those skilled in the art will recognize that a similar procedure may be used to fully contract a four (or more) panel support member, in which case the resulting structure would be a four- (or more) lobed structure.

The foregoing processes are performed in reverse to transform the prosthetic valve from its contracted state to its expanded state. For example, beginning with the prosthetic valve in its “tri-lobe” position shown inFIG. 1C, the three vertices58may be extended radially to achieve the “tri-star” shape shown inFIG. 1B. The “tri-star” shape shown inFIG. 1Bis typically not stable, as the panels36tend to spontaneously expand from the inverted shape to the fully expanded shape shown inFIG. 1Aunless the panels are otherwise constrained. Alternatively, if the panels do not spontaneously transition to the expanded state, it will typically only require a slight amount of force over a relatively short amount of distance in order to cause the panels to fully expand. For example, because of the geometry of the three panel structure, a structure having an expanded diameter of about 21 mm would be fully expanded by insertion of an expanding member having a diameter of only 16 mm into the interior of the structure. In such a circumstance, the 16 mm diameter member would contact the centerline of each panel and provide sufficient force to cause each panel to transform from the inverted shape shown inFIG. 1Bto the fully expanded shape shown inFIG. 1A. This is in contrast to a typical “stent”-like support structure, which requires an expanding member to expand the stent to its full radial distance.

Additional details of this and other embodiments of the prosthetic heart valve and scaffolding structures are provided in the '126 application, to which the present description refers. It is to be understood that those prosthetic heart valves and scaffolding structures are only examples of such valves and prosthetic devices that are suitable for use with the devices and methods described herein. For example, the present devices and methods are suitable for delivering valves and prosthetic devices having any cross-sectional or longitudinal profile, and is not limited to those valves and devices described in the '126 application or elsewhere.

Turning to the deployment devices and methods, in one aspect of the present invention, a delivery catheter for prosthetic heart valves and other devices is provided. The delivery catheter is preferably adapted for use with a conventional guidewire, having an internal longitudinal lumen for passage of the guidewire. The delivery catheter includes a handle portion located at a proximal end of the catheter, a deployment mechanism located at the distal end of the catheter, and a catheter shaft interposed between and operatively interconnecting the handle portion and the deployment mechanism. The deployment mechanism includes several components that provide the delivery catheter with the ability to receive and retain a prosthetic valve or other device in a contracted, delivery state, to convert the prosthetic device to a partially expanded state, and then to release the prosthetic valve completely from the delivery device. In several preferred embodiments, the deployment mechanism includes an outer slotted tube, a plurality of wrapping pins attached to a hub and located on the interior of the slotted tube, and a plurality of restraining members that extend through the wrapping pins to the distal end of the catheter. Each of the deployment mechanism components is individually controlled by a corresponding mechanism carried on the handle portion of the catheter. The deployment mechanism preferably also includes a nosecone having an atraumatic distal end.

In several particularly preferred embodiments, the restraining members comprise tethers in the form of a wire, a cable, or other long, thin member made up of one or more of a metal such as stainless steel, metallic alloys, polymeric materials, or other suitable materials. A particularly preferred form of the tethers is suture material. In several embodiments, the tethers are adapted to engage the guidewire that extends distally past the distal end of the delivery catheter. The tethers preferably engage the guidewire by having a loop, an eyelet, or other similar construction at the distal end of the tether. Optionally, the tether is simply looped around the guidewire and doubles back to the catheter handle. Thus, the tethers are released when the guidewire is retracted proximally into the delivery catheter. In still other embodiments, the tethers may be released from the guidewire by actuation of a member carried on the handle mechanism at the proximal end of the catheter. In still other embodiments, a post or tab is provided on the guidewire, and the tether engages the post or tab but is able to bend or break free from the post or tab when a proximally-oriented force is applied to the tethers.

In a second aspect of the present invention, several optional active deployment mechanisms are described. The active deployment mechanisms are intended to convert a prosthetic valve, scaffolding structure, or similar device from an undeployed, partially deployed, or not-fully deployed state to its fully expanded state. Several of the active deployment mechanisms take advantage of the fact that the preferred prosthetic valves and scaffolding structures require only a small amount of force applied to any of a large number of points or locations on the valve or structure in order to cause the valve to fully expand. Exemplary embodiments of the active deployment mechanisms include embodiments utilizing expandable members that are placed into the interior of the prosthetic valve and then expanded; embodiments that operate by causing the hinges of the undeployed prosthetic valve to open, thereby transitioning to the fully expanded state; embodiments that include implements that engage one or more of the panels to cause the panel to expand to its deployed state; and other embodiments described herein.

Other aspects, features, and functions of the inventions described herein will become apparent by reference to the drawings and the detailed description of the preferred embodiments set forth below.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A. Delivery Devices and Methods of Use

Devices for delivering prosthetic valves and other devices to a treatment location in a body lumen are described below, as are methods for their use. The delivery devices are particularly adapted for use in minimally invasive interventional procedures, such as percutaneous aortic valve replacements.FIG. 2illustrates a preferred embodiment of the device, in the form of a delivery catheter. The delivery catheter100includes a handle mechanism102located at the proximal end of the catheter, a deployment mechanism104located at the distal end of the device, and a shaft106extending between and interconnecting the handle mechanism102and the deployment mechanism104. The catheter100is preferably provided with a guidewire lumen extending through the entire length of the catheter, such that a guidewire108is able to extend through the delivery catheter in an “over-the-wire” construction. In an optional embodiment (not shown in the drawings), the catheter100is provided with a “rapid-exchange” construction whereby the guidewire exits the catheter shaft through an exit port located near the distal end of the catheter. The cross-sectional profile of the deployment mechanism104and the shaft106are of a sufficiently small size that they are able to be advanced within the vasculature of a patient to a target location, such as the valve root of one or more of the valves of the heart. A preferred route of entry is through the femoral artery in a manner known to those skilled in the art. Thus, the deployment mechanism104has a preferred maximum diameter of approximately 24 Fr. It is understood, however, that the maximum and minimum transverse dimensions of the deployment mechanism104may be varied in order to obtain necessary or desired results.

The deployment mechanism104is provided with components, structures, and/or features that provide the delivery catheter with the ability to retain a prosthetic valve (or other prosthetic device) in a contracted state, to deliver the valve to a treatment location, to convert the prosthetic valve to its deployed state (or to allow the valve to convert to its deployed state on its own), to retain control over the valve to make any necessary final position adjustments, and to convert the prosthetic valve to its contracted state and withdraw the valve (if needed). These components, structures, and/or features of the preferred deployment mechanism are described below.

Turning toFIGS. 3 and 3A, the deployment mechanism104is shown in its fully contracted state for use when the mechanism104has not yet reached the target site within the body of a patient, such as prior to use and during the delivery process. The deployment mechanism104includes a slotted tube110that is connected to an outer sheath112of the catheter shaft106, such as by way of the attachment collar111(shown inFIG. 3A). Thus, longitudinal movement or rotation of the outer sheath112causes longitudinal movement or rotation of the slotted tube110. The slotted tube110is a generally cylindrical body that includes a plurality of longitudinal slots114that extend from the distal end of the slotted tube110to near its proximal end. In the preferred delivery catheter, the slotted tube110includes three slots114spaced equidistantly about the circumference of the slotted tube110. The slots114have a length and width that are sufficient to accommodate the extension of portions of the prosthetic valve30therethrough, as described more fully below in reference toFIG. 7, described elsewhere herein. The slotted tube110is preferably formed of stainless steel or other generally rigid material suitable for use in medical devices or similar applications.

The deployment mechanism104may also include a retainer ring116and a nosecone118. Although the retainer ring116and nosecone118are not necessary parts of the delivery catheter, each of these components may provide additional features and functionality when present. The nosecone118is located at the distal end of the delivery catheter and is preferably provided with a generally blunt, atraumatic tip120to facilitate passage of the catheter through the patient's vasculature while minimizing damage to the vessel walls. The nosecone118is preferably formed of any suitable biocompatible material. In several preferred embodiments, the nosecone is formed of a relatively soft elastomeric material, such as a polyurethane, a polyester, or other polymeric or silicone-based material. In other embodiments, the nosecone is formed of a more rigid material, such as a plastic, a metal, or a metal alloy material. The nosecone may be coated with a coating material or coating layer to provide advantageous properties, such as reduced friction or increased protection against damage. It is also advantageous to provide the nosecone with an atraumatic shape, at least at its distal end, or to form the nosecone118of materials that will provide the atraumatic properties while still providing structural integrity to the distal end of the device. The nosecone118preferably includes a plurality of throughholes122that extend through the length of the nosecone to allow passage of a plurality of tethers124, which are described more fully below. A pair of slots119are formed on the exterior of the nosecone118. The slots119provide a pair of surfaces for a wrench or other tool to grasp the nosecone118to enable manual manipulation of the nosecone118, for purposes to be described below.

The retainer ring116is a generally cylindrically shaped ring that is located generally between the slotted tube110and the nosecone118. More precisely, when the deployment mechanism104is in the fully contracted state shown inFIGS. 3 and 3A, the retainer ring116preferably overlaps a ledge126formed on the distal end of the slotted tube110. Alternatively, the inner diameter of the retainer ring116may be formed slightly larger than the outer diameter of the slotted tube110, thereby allowing the distal ends of the slotted tube110to slide within the retainer ring116without the need for a ledge126. In this way, the retainer ring116prevents the distal ends of the slotted tube110from bowing outward due to pressure caused by the prosthetic valve being stored within the deployment mechanism104.

The proximal end of the retainer ring116engages a bearing128that is formed integrally with the nosecone118, and that allows the nosecone118to rotate inside and independently from the retainer ring116. As described below, the slotted tube110is rotated relative to the nosecone shaft136and the wrapping pins130during some operations of the deployment mechanism, primarily during the expansion and contraction of the prosthetic valve. Without the bearing128(or a suitable alternative), the prosthetic valve would tend to bind up within the deployment mechanism and prevent relative rotation between the slotted tube110and the wrapping pins130. Thus, the provision of the bearing128engaged with the retainer ring116facilitates this rotation of the slotted tube110, which engages the retainer ring116.

Additional features of the interior of the deployment mechanism are illustrated in the cross-sectional view shown inFIGS. 3A-G. A plurality of fixed wrapping pins130are attached to a wrapping pin hub132and extend longitudinally from the hub132toward the distal end of the catheter. The preferred embodiment of the delivery catheter includes three wrapping pins130, although more or fewer are possible. The hub132is attached to a wrapping pin shaft134that extends proximally from the hub132beneath the outer sheath112of the catheter shaft106. Thus, movement or rotation of the wrapping pin shaft134causes longitudinal movement or rotation of the hub132and the three wrapping pins130. A wrapping pin stabilizer133is slidably attached to the outer surfaces of each of the wrapping pins130. The pin stabilizer133is a generally disc-shaped member having a center hole133aand three equally spaced throughholes133bto accommodate the three wrapping pins130. As described below, in certain orientations of the deployment mechanism104, the pin stabilizer133provides support and stability to the wrapping pins130extending distally from the wrapping pin hub132.

Turning toFIGS. 3D-F, in several of the preferred embodiments, the tethers124extend through or are otherwise engaged with the wrapping pins130. The Figures illustrate several methods by which this is done. In the closed configuration, shown inFIG. 3D, the wrapping pin130includes a central lumen131athrough which the tether124extends. The lumen131aextends through the length of the wrapping pin130and through the hub132, allowing the tether to extend proximally to the handle mechanism102. In the open configuration, shown inFIG. 3E, the wrapping pin130includes a channel131bformed on its underside. The tether124is able to be received in the channel131b, although it is not necessarily retained therein. In the guided configuration, shown inFIG. 3F, the wrapping pin130includes a channel131bformed on its underside. A tether guide135is located in the channel131b, and is preferably attached to the handle housing152by welding, adhesive, or other suitable method. The tether124is routed through the guide135, and is thereby retained within the guide135.

A nosecone shaft136is located internally of the wrapping pin shaft134. The nosecone118is attached to the nosecone shaft136, and the nosecone shaft136is slidably received through the wrapping pin hub132. However, the nosecone shaft136is fixed to the wrapping pin stabilizer133. Thus, longitudinal movement of the nosecone shaft136causes longitudinal movement of the nosecone118and the pin stabilizer133, independent of any of the other components of the deployment mechanism104. However, rotation of the handle housing152causes rotation of the nosecone118, the pin stabilizer133, and the wrapping pins130. The nosecone shaft136is hollow, thereby defining a guidewire lumen137through its center.

A plurality of wrapping pin sockets138are formed on the proximal side of the nosecone118. Each socket138is generally cylindrical and has a size adapted to receive the distal portion of a wrapping pin130therein. When the distal ends of the wrapping pins130are engaged with their respective sockets138, the sockets138provide support and rigidity to the wrapping pins130. This support and rigidity is particularly needed during the wrapping and unwrapping of the prosthetic valve, as described more fully below. During those operations, a large amount of strain is imparted to each of the wrapping pins130, which strain is absorbed in part by the sockets138formed in the nosecone118. Each socket138is also provided with a hole140that provides access to a respective throughhole122in the nosecone118. As described more fully below, this provides a passage for a tether124that is contained within each wrapping pin130to extend through the hole140in each socket, through the throughhole122to the distal end of the nosecone118.

Although it is not shown in the cross-sectional view inFIG. 3A, a prosthetic valve30such as the type described herein in relation to FIGS.1A-C—and in the '126 application—may be retained on the wrapping pins130in the interior of the slotted tube110. A suitable method for loading the valve30into the device will be described below. The valve30is retained in a contracted, multi-lobe state (see, e.g.,FIG. 1C) in which each “lobe” is generally wrapped around a respective wrapping pin130, and held in place there by engagement with the interior surface of the slotted tube110.

Turning now toFIGS. 4-6, the handle mechanism102will be described. The handle mechanism102includes a slotted tube grip150that is fixedly connected to the outer sheath112while being slidably and rotatably mounted on a handle housing152. The handle housing152is a generally cylindrical hollow shaft. The slotted tube grip150is preferably formed of or covered with a corrugated polymer or rubber material to provide the ability to easily grasp and manipulate the grip150. Similarly, a wrapping pin grip154, also preferably formed of or covered with a corrugated polymer or rubber material, is slidably mounted to the handle housing152. The wrapping pin grip154includes a bolt156that extends through a slot158formed in the handle housing152, to engage the proximal end of the wrapping pin shaft134. A tether grip160is slidably mounted over the proximal end of the handle housing152. The tether grip160is also generally cylindrical, having a slightly larger diameter than the handle housing152, thereby allowing the tether grip160to slide over the handle housing152in a telescoping manner. A locking screw162extends through a slot164formed in the tether grip160and into the side of the handle housing152near its proximal end. The locking screw162allows the user to fix the position of the tether grip160relative to the handle housing152by screwing the locking screw162down.

Three tether clamps166extend from the proximal end of the tether grip160. Each tether clamp166is independently clamped to a tether124that extends through the catheter to its distal end, as explained in more detail herein. Each tether clamp166also includes a spring mechanism (not shown) that provides independent tensioning for each tether124. The proximal end of the nosecone shaft136extends out of the proximal end of the tether grip160, between the three tether clamps166, terminating in a small cylindrical nosecone shaft grip168. The guidewire108is shown extending out of the proximal end of the nosecone shaft136.

The preferred embodiment of the valve delivery catheter so described is intended to be used to deliver and deploy a prosthetic device, such as a prosthetic heart valve, to a patient using minimally invasive surgical techniques. Turning toFIGS. 6-11, a representative method of use of the device will be described. The device is intended to be introduced to the vasculature of a patient over a standard guidewire that has been previously introduced by any known technique, with access via the femoral artery being the preferred method. The guidewire is advanced to the treatment location under x-ray or other guidance, such as to the root of a heart valve, such as the aortic valve. Once the guidewire is in place, the valve delivery catheter100is advanced over the guidewire until the deployment mechanism104reaches the treatment location. During the delivery process, the deployment mechanism is in the fully contracted state shown, for example, inFIGS. 2 and 3.

Once the deployment mechanism104is located near the treatment location, the valve deployment process begins. The guidewire108is initially left in place through the deployment process, and is not withdrawn until a particular point in the process defined below. The valve deployment process includes manipulation of the slotted tube grip150, wrapping pin grip154, and tether grip160located on the handle mechanism102, which cause a series of manipulations of the slotted tube110, wrapping pin hub132and wrapping pins130, and the tethers124, in order to release and deploy the prosthetic valve in a manner that provides control during deployment and the ability to precisely position, re-position, and (if necessary) retrieve the prosthetic valve at any time during the deployment process.FIG. 6illustrates several of the positions of the components of the handle mechanism102during the preferred deployment process. These positions correspond to several of the delivery steps illustrated inFIGS. 7-11.

As noted elsewhere herein, it is possible to provide valves that are contracted into other sizes and orientations (such as two lobes or four or more lobes), which would also include a delivery catheter having a different number of slots in the slotted tube110and a different number of wrapping pins130. For clarity, the present description will focus entirely upon the valve30having three panels36and three hinges52, and a delivery catheter100having three slots114in the slotted tube110and three wrapping pins130.

Turning toFIGS. 6 and 7, the first step in deploying the prosthetic valve30is to partially expand the contracted valve from the “tri-lobe” shape (seeFIG. 1C) to the “tri-star” shape (seeFIG. 1B). This is done by causing relative rotation between the slotted tube110and the wrapping pins130. As shown inFIG. 6, this is done by rotating the slotted tube grip150around the longitudinal axis of the delivery catheter, thereby causing the slotted tube110to rotate around the wrapping pins130, which are maintained stationary. This relative rotation is facilitated by the provision of the bearing128in the nosecone118of the deployment mechanism104, as illustrated inFIG. 3A. As the slotted tube110rotates relative to the wrapping pins130, each of the vertices58of the prosthetic valve30is caused to extend outward through its respective slot114in the slotted tube110. Rotation of the slotted tube grip150is stopped when the valve30achieves the “tri-star” shape shown inFIG. 7. At all times during the process up to this point, the adjustable components on the handle mechanism (i.e., the tether grip160, the wrapping pin grip154, and the slotted tube grip150) are maintained in position “a”, wherein the tether grip160is in its fully retracted position, and the wrapping pin grip154and slotted tube grip150are each in their fully advanced positions.

Turning next toFIGS. 6 and 8, the next step in the deployment process is to retract the slotted tube110to further expose the prosthetic valve30. This is done by retracting the slotted tube grip150to position “b” (FIG. 6) while maintaining the wrapping pin grip154and tether grip160in the same position “b”. Retracting the slotted tube110causes the valve30to become more exposed, but the valve30is maintained in the “tri-star” shape by the wrapping pins130which continue to engage each of the three panels36of the valve30. Although not shown inFIG. 8, the distal ends of the wrapping pins130also remain seated in the wrapping pin sockets138located in the proximal-facing portion of the nosecone118. In this “b” position, the wrapping pin stabilizer133is located just proximally of the valve30and is just distal of the wrapping pin hub132.

Next, turning toFIGS. 6 and 9, the wrapping pins130are retracted by retracting the wrapping pin grip154to position “c” (as shown in the Figure, transitioning from position “b” to position “c” requires no adjustment of either the slotted tube grip150or the tether grip160). Retracting the wrapping pins130causes the wrapping pins130to become disengaged from the valve30and to retract to the interior of the slotted tube110. The wrapping pin stabilizer133, which is fixed to the nosecone shaft136, slides along the length of the wrapping pins130until maximum retraction of the wrapping pins130, which corresponds to the position shown inFIG. 9, with the stabilizer133near the distal ends of each of the wrapping pins130. In this position, the stabilizer133provides support and rigidity to the nosecone shaft136, which is otherwise only supported by the wrapping pin hub132. As shown, for example, inFIG. 9, the stabilizer133effectively decreases the cantilever length of the nosecone shaft136, thereby providing it with increased stability. The stabilizer133also serves as a backing member for the prosthetic valve30, preventing the valve30from moving proximally as the wrapping pins130are retracted. Further, the stabilizer133also serves as a guide for the tethers124as they extend from the distal ends of the wrapping pins130.

The valve remains in the “tri-star” position due to the presence of the tethers124, the spacing of which is maintained by the holes in the stabilizer133through which the wrapping pins130and tethers124extend. In the preferred embodiment shown inFIGS. 9 and 9A, a tether124extends through each of the wrapping pins130, through the hole140in the socket138, through the throughholes122in the nosecone118, and is looped around the guidewire108on the distal side of the nosecone118. The tethers124each extend proximally through and within the catheter shaft106and is received and retained in its respective tether clamp166near the proximal end of the catheter100. In the position shown inFIG. 9, the tethers124are all maintained sufficiently taut that they retain the valve30in the “tri-star” orientation shown in the Figure. This corresponds with position “c” of the tether grip160relative to the handle housing152, shown inFIG. 6.

In an alternative embodiment, the tethers124may be tensioned by manipulation of the distal connection of the tethers124to the guidewire108. For example, rotation of the nosecone shaft136will cause the tethers124to wrap around the guidewire108, thereby providing tension to the tethers124. Other suitable methods for tensioning the tethers124are also contemplated, as will be understood by those skilled in the art.

Turning next toFIGS. 6 and 10, expansion of the valve30is obtained by loosening the tethers124that otherwise hold the valve30in the “tri-star” position. This transition is achieved by advancing the tether grip160to position “d”, as shown inFIG. 6. (Note: Transitioning from position “c” to position “d” requires no adjustment of either the slotted tube grip150or the wrapping pin grip154). Advancement of the tether grip160relative to the handle housing152creates slack in the tethers124, which slack is taken up by the radial expansion of the valve30. In the typical deployment, the valve30will automatically fully expand to the deployment position shown inFIG. 10when the tension is released from the tethers124. For those situations in which the valve30does not automatically expand, or when the valve only partially expands, one or more alternative mechanisms and/or methods may be utilized to obtain full expansion. Several of these preferred mechanisms and methods are described below in Section B.

It is significant that, in the position shown inFIG. 10, the tethers124no longer interfere with the expansion of the valve30, but they remain in control of the valve30. In this position, it is possible to make any final positional adjustments of the valve30, if necessary. This can be done by simply advancing or withdrawing the catheter100, which tends to drag or push the valve30along with it. This may also be facilitated by slight advancement of the wrapping pin grip154and/or retraction of the tether grip160, each of which actions will tend to apply tension to the tethers154. In this manner, the valve position may be adjusted by the user while the valve is in its fully expanded state, under control of the tethers124.

Alternatively, the valve30may be partially or fully contracted once again by increasing the tension on the tethers124, as by retracting the tether grip160relative to the handle housing152. (I.e., moving from position “d” to position “c” inFIG. 6). If necessary, the valve30may be fully contracted by retracting the tether grip160, and then the deployment mechanism104may be fully restored to the undeployed position by simply reversing the above steps, in order. (I.e., moving to position “c”, then position “b”, then position “a”). This reversal of the process includes a step of advancing the wrapping pins130back over the contracted valve panels as the valve30is maintained in the “tri-star” shape. This process is facilitated by the presence of the tethers124, which act as guides for the wrapping pins130to “ride up” over the edges of the valve panels under the guidance of the tethers124. Once the wrapping pins130are in place, the slotted tube110is advanced over the valve30, with each of the vertices of the valve “tri-star” extending through its respective slot114. The slotted tube110is then rotated relative to the wrapping pins130and valve30, causing the valve to transition to the fully contracted “tri-lobe” shape fully contained within the slotted tube110. At that point, the delivery catheter may be removed from the patient without deploying the valve30. Any or all of these adjustment or removal steps may be taken, depending upon the clinical need or depending upon any situation that may arise during the deployment procedure.

Turning toFIGS. 6 and 11, assuming that the valve30is placed in its final position and is ready to be released, the valve is released from the delivery catheter100by retracting the guidewire108to a position such that the distal end of the guidewire108no longer extends past the distal end of the nosecone118of the delivery catheter100. At this point, the tethers124are released from their engagement with the guidewire108. Preferably, the tethers124are then retracted at least into the wrapping pins130, and may alternatively be fully retracted through and from the proximal end of the delivery catheter100. This is reflected as handle position “f” inFIG. 6, in which the tether grip160is retracted at least to its initial position, and no change is made to the positions of either the wrapping pin grip154or the slotted tube grip150. As shown inFIG. 11, the valve30is completely free from the delivery catheter100. The nosecone118remains distal of the valve30, and the nosecone shaft136extends through the body of the valve30.

To complete the delivery process, the delivery catheter is preferably contracted to its pre-delivery state by advancing the wrapping pins130into engagement with the nosecone118by advancing the wrapping pin grip154on the handle back to position “a”, then by advancing the slotted tube110into engagement with the retainer ring116by advancing the slotted tube grip150on the handle back to position “a”. At this point, the delivery catheter100may be removed from the patient, leaving the prosthetic valve30in place.

B. Variations in Construction, Components, and/or Features of Delivery Device

Preferred delivery catheters and methods of use are described above. A number of variations of several of the components, features, and other aspects of the device have been contemplated, and are described below.

Turning first toFIGS. 12A-B, an alternative method of connecting the tethers124to the guidewire108is shown. In the embodiment described above, the tethers124are looped over the guidewire108. In the embodiment shown inFIGS. 12A-B, each tether124has an eyelet125formed at its distal end. The eyelet125is connected to the tether by an adhesive bond, or by crimping, or by any other suitable method. Each eyelet125has a hole formed at its distal end that is large enough to accommodate the guidewire108extending therethrough. The eyelet125may have a generally curved shape to rest alongside the nosecone118, and a terminal end that is generally perpendicular to the longitudinal axis defined by the guidewire108.

Turning toFIGS. 12C-D, an optional recess131may be formed in the distal end of each of the wrapping pins130. The recess131is preferably formed having a shape and size to accommodate the eyelet125that is optionally provided at the distal end of each of the tethers124. Accordingly, when no recess131is available (see, e.g.,FIG. 12C), the eyelet125may be unable to be withdrawn into the lumen provided for passage of the tether124. When a recess131is provided (see, e.g.,FIG. 12D), the eyelet125is retracted into the recess131and does not extend out of the distal end of the wrapping pin130.

FIG. 12Eillustrates an embodiment including a plurality of dual or redundant tethers124a-b. As shown in the Figure, a pair of tethers124a-bare provided on each of the panels of the valve30. The dual tethers124a-bmay be provided to increase tether strength, where needed, or to provide redundancy in the case of failure of one of the tethers.FIGS. 12F and 12Gillustrate two possible methods for attaching the dual tethers124a-bto a guidewire108. In the first method, shown inFIG. 12F, a collar176is formed near the distal ends of and is attached to both of the tethers124a-bnear their distal ends, thereby forming a loop through which the guidewire108extends. In this construction, the loop will remain even if one of the tethers fails. In the second method, shown inFIG. 12G, each of the tethers124a-bincludes a separate attachment loop178a-b, through which the guidewire108extends. In each method, the tethers124a-bare released when they are disengaged from the guidewire108in the manner described above.

Turning toFIG. 13, a valve stop142may be provided on each of the tethers124. Each valve stop142is in the form of a small cleat, barb, tab, or other transverse extension from the tether124. The valve stop142is intended to provide another mechanism to prevent the valve30from slipping or migrating relative to the tethers124when the tethers124are in engagement with the valve30. Thus, the valve stop142is located at a particular known position on each tether124to provide an optimal amount of control to the device100when the tethers124are engaged with the valve30.

FIGS. 14A-Billustrate tethers formed of linkages144and tether sections146. Each tether includes an eyelet125at its distal end connecting the tether to the guidewire108. The eyelet125is connected directly to a first linkage member144a, which may comprise a relatively rigid member formed of a metallic material, a rigid polymeric material, or the like. The linkage144is of a length sufficient to accommodate the valve30in its expanded state, as shown inFIG. 14A. The first linkage144ais connected to a tether section146that extends through the length of the valve30, and then connects to a second linkage member144b. The second linkage member144bthen connects to another section of the tether146, which extends proximally into the remainder of the delivery catheter. Each linkage member144a,144bincludes a pivot at each end thereof, thereby enabling the linkage member144a,144bto pivot relative to the member to which it is attached. Thus, when the tethers are relaxed, the valve30is allowed to expand, as shown inFIG. 14A. However, when the tethers are pulled taut, the linkages144a,144bpivot, thereby causing the tethers to become taut and to convert the valve to its “tri-star” shape, as shown inFIG. 14B. Preferably, the nosecone118is provided with slots that accommodate the first linkage members144awhen they are pulled taut in the position shown inFIG. 14B.

FIG. 15illustrates a slight variation of the preferred embodiment described above. In this embodiment, the tethers124each include a loop148formed on their distal ends. Each loop148is adapted to engage the guidewire108. The tethers124, in turn, are routed through throughholes122formed in the nosecone118, as described above. Each tether124is then routed through a lumen formed in its respective wrapping pin130. This particular routing orientation provides a mechanical advantage over other routing orientation because the tethers are captured by the nosecone118and wrapping pins130in close relation to the valve30. This orientation also results in less migration of the tethers from side-to-side relative to the valve30.

Turning next toFIGS. 16A-B, an alternative method for routing the tethers124in and around the nosecone118is to provide a plurality of slots121on the exterior of the nosecone118. Each slot121is adapted to receive and retain a tether124when the tethers124are pulled taut. The slots121also allow the tethers to arise out of and disengage from its respective slot121, for example, when the tethers124are slack and the valve30expands.

FIG. 17illustrates another embodiment containing tethers formed of two separate components, including a thick, or broad primary tether124aand a thin, or narrow secondary tether124b. The primary tether124amay be formed of a round or flat wire, and may be provided as either a straight component or it may be provided with a degree of shape memory. The secondary tether124bmay be made from a finer, smaller diameter material that is less traumatic to the vessel when it is pulled from between the valve30and the vessel. The secondary tether124bmay also be more easily retracted through the wrapping pins130. Although a two-component tether124is shown, it should be appreciated that three or more components may also be incorporated to make up the tether124and to obtain various performance characteristics.

Turning next toFIGS. 18A-B, a pair of loops170are shown formed on the external surface of the valve30. The loops170are intended to provide an engagement member on the surface of the valve30for the tethers124to engage to prevent the tethers124from migrating on the surface of the valve30. For example, if the tether124migrates from the centerline of a valve panel36, it may no longer have the ability to cause the valve panel36to invert or to restrain it in its inverted shape. By providing the loops170, such migration of the tethers124is substantially prevented. It will be appreciated that mechanisms other than loops170may also be provided to restrain tether migration. For example, holes, barbs, slots, bumps, or other members may be provided on the surface or integrated into the body of the valve panel36to substantially restrain tether migration. One or more such members may be sufficient to provide sufficient restraining capability.

Turning toFIGS. 19A-D, several alternative wrapping pin embodiments are illustrated. The alternative embodiments represent several methods by which wrapping pin deflection may be overcome. As shown, for example, inFIG. 19A, when the wrapping pin hub132is rotated to cause wrapping up of a prosthetic valve30by the wrapping pins130, an amount of torque “T” is imparted to the hub132, and a corresponding deflecting force “F” is imparted to the distal end of the wrapping pin130. The deflecting force “F” tends to cause the wrapping pin130to deflect in the direction of the deflecting force “F”, which tends to interfere with the wrapping procedure. To counteract the deflection force, the wrapping pin130may be formed having a gradual curving shape, as shown inFIG. 19B, to offset the deflection and to provide more even wrapping of the valve30. The degree and nature of the curvature will vary depending upon the materials, sizes, and other properties of the delivery device and the valve, although the curvature will typically be directed toward the deflecting force. Alternatively, the wrapping pin130may be attached to the hub132at a fixed angle, or canted, as illustrated inFIG. 19C. Once again, the cant angle may be determined and will vary. Another alternative is shown inFIG. 19D, in which the wrapping pin130is provided with an offset between its proximal and distal ends. Once again, the degree of offset may be varied according to need for a given device.

Turning toFIGS. 20A-B, in several additional alternative embodiments, the wrapping pins330are not fixed in shape or orientation relative to the hub332. In several such embodiments, the wrapping pins330include articulating segments331connected by rotating joints332, thereby allowing each wrapping pin330to move radially relative to the longitudinal axis of the device. The concerted movement of the multiple wrapping pins330(three pins being preferred, but more or fewer also being possible) allows the structure to act as a gripper for manipulating the prosthetic valve30. In the preferred embodiments, movement of each articulated wrapping pin330is independently controlled, thereby allowing the user to move each articulated wrapping pin330independently from a position generally comparable to that of the fixed wrapping pins330illustrated in the drawings (seeFIG. 20A), to a position substantially radially outwardly spaced from the longitudinal axis of the device (seeFIG. 20B). Thus, the close-in position (FIG. 20A) is suitable for restraining the valve in its contracted or “tri-star” shape, while the radially spaced position (FIG. 20B) is suitable for releasing the valve to its expanded state, or for retrieving the valve from its expanded state in order to transition the valve back to its contracted state.

FIGS. 21A-Billustrate an alternative construction for the slotted tube110. In this construction, each of the longitudinal members180forming the slotted tube110includes an internal base portion182formed of a rigid material such as stainless steel or other metallic material, or a rigid polymeric material. The base portion182is intended to provide strength and resiliency to the slotted tube110to perform its functions of receiving, retaining, and manipulating the valve30in response to manipulations of the components contained on the handle mechanism102of the delivery catheter. Surrounding the base portion182of the slotted tube110are a number of air gaps184and/or filled sections186that are filled with a more flexible, less rigid material relative to the material forming the base portion182. A wide variety of filler materials are possible, including several polymeric material such as polyurethane, or other soft materials such as one or more silicone based materials. The purpose for the air gaps184and/or filled portions186are to provide a less traumatic construction to reduce the likelihood of causing damage to the valve30or any of its panels36or hinges52while the valve is being loaded, stored, or deployed. By providing an air gap184or filled sections186on the edges of the longitudinal sections180of the slotted tube110, the valve30is more protected during roll-up or deployment of the valve, during which time the edges of the longitudinal members180impose force against the valve panels36to cause them to roll up within the deployment mechanism104or to deploy out of the slotted tube110.

Turning toFIG. 21C, another mechanism for protecting the valve panels36while they are retained within the slotted tube110is comprised of a series of runners190formed on the internal-facing surfaces of the longitudinal members180making up the slotted tube110. The runners190provide a raised surface upon which the panels36will ride to minimize the contact between the panels36and the slotted tube110. The runners190also serve to decrease friction between the two components and decrease the amount of abrasion that is imparted to the panels.

FIGS. 22A-Billustrate another alternative construction for a portion of the deployment mechanism104of the delivery catheter100. In this alternative construction, the wrapping pins130are not needed. Instead, an inner slotted tube194is provided coaxially with and interior to the outer slotted tube110. As the inner slotted tube194is rotated relative to the outer slotted tube110, the valve30is converted from a “tri-star” shape to a “tri-lobe” shape, as shown, for example, inFIG. 22A. Reversing the relative rotation causes the valve30to extend out of the slots formed in each of the inner slotted tube194and the outer slotted tube110to form the “tri-star” shape shown inFIG. 22B. The valve30may then be deployed by retracting both the inner slotted tube194and the outer slotted tube110relative to the valve30, thereby allowing the valve to expand to its deployed state.

FIGS. 23A-Cillustrate an optional shape set nosecone shaft136. The shape set nosecone shaft136includes a pre-set shape formed into the distal end of the nosecone shaft136to facilitate the ability for the distal end of the delivery catheter100to pass over the aortic arch. This is particularly useful when the delivery catheter100is used for delivery of a prosthetic aortic valve. The shape set shown inFIG. 23Ais generally in the form of a hook-shape, although other shapes is possible in order to improve the performance of the catheter. The shape set is also useful to stabilize the position of the catheter once it is delivered over the aortic arch. The shape set may be imparted by any mechanical or other method known to those skilled in the art. An optional tensioning member336may be provided on the external surface of the nosecone shaft136. The tensioning member336is used to straighten the curvature of the shape set nosecone shaft136under the user's control. For example, as a tension force “T” is imparted to the tensioning member336, such as by the user pulling proximally on the tensioning member336from the handle mechanism102, the nosecone shaft136is straightened, as shown inFIG. 23C. The operation of the tensioning member336thereby provides the ability to manipulate the distal end of the delivery catheter100in a manner that provides an ability for the user to effectively steer the catheter over difficult or tortuous portions of the patient's vasculature. Other uses of the tensioning member336are described elsewhere herein.

C. Active Deployment of Undeployed and Not-Fully Deployed Valves

Although typically a prosthetic valve30such as those illustrated and described above in relation to FIGS.1A-C—and those described in the '126 application and elsewhere—will fully deploy once it is released from the delivery catheter, it sometimes occurs that the valve does not deploy, or does not fully deploy. In most of these circumstances, the failure to deploy or to fully deploy is due to the fact that one or more panels36of a multi-panel valve30fails to change from its inverted state to its expanded state. One such example is illustrated inFIG. 24B, in which two panels36of a three-panel prosthetic valve30have expanded, but the upper panel36remains in a partially inverted state. Several mechanisms and methods for actively correcting these undeployed and not-fully deployed valves are described herein.

Several of the described mechanisms take advantage of the fact that, in most circumstances of non-full deployment, only a point contact is needed to cause the valve to fully expand. Accordingly, it may not be necessary to fully occlude the vessel in order to cause the valve or similar prosthetic device to fully expand. Thus, in most of the mechanisms and methods described, fluid flow or perfusion is still allowed through the valve and vessel as the active deployment procedure takes place. This is to be distinguished from the deployment methods applicable to most stent-like prosthetic devices in which fibrillation is induced to decrease flow during the deployment procedure. No such fibrillation is required for delivery and deployment of the prosthetic valves and similar devices described herein, nor for the active deployment mechanisms and methods described.

Turning toFIGS. 24A-C, a first such mechanism200includes a collar202and a plurality of wire forms204extending proximally from the collar202. The mechanism200is intended to ride closely along the nosecone shaft136on any of the embodiments of the delivery catheter100described herein. As the mechanism200is advanced distally, it will enter and pass through the body of the partially-expanded valve30. Once it is located there, the collar202may be retracted proximally, as shown by the arrow “A” inFIG. 24A, thereby causing the wire forms204to bow radially outward, (see, e.g.,FIGS. 24A and 24C), engaging any inverted panels36of the valve30and causing them to expand to the fully expanded state. Preferably, the collar202is retracted by a tether or other control member that is connected to the collar202and that extends proximally to the handle where it can be manipulated by the user. Once the valve30is fully expanded, the collar202is advanced distally to cause the wire forms204to return to their unbowed state. The mechanism200may then be retracted into the delivery catheter100. In alternative embodiments, the collar202may be provided with threads that engage threads formed on the nosecone shaft136. Any other engagement providing relative movement between the collar202and the nosecone shaft136is also suitable.

As an alternative to the wire forms204shown in the above embodiment, a continuous segment of metallic or polymeric material having sufficient elasticity to expand and contract in the manner shown may be used. Other alternatives including using only a single band or material, or two, three, or more bands. Other alternative constructions and materials capable of expanding and contracting in the involved space internal of the undeployed or partially deployed prosthetic valve30are also contemplated, and are suitable for use as the active deployment mechanism200described herein.

Another alternative construction for the active deployment mechanism is illustrated inFIGS. 25A-C. A partially deployed valve30includes an upper panel36that has not yet fully deployed. The deployment mechanism200comprises a collar212and a plurality of wire forms214extending proximally from the collar212. Prior to use, the collar212is located internally of the catheter shaft106along the nosecone shaft136, and the wire forms214lie flat along the nosecone shaft136proximally to the collar212. (SeeFIG. 25A). The collar212is advanced distally through the partially deployed valve30until the collar212engages the proximal side of the nosecone118, where further distal advancement is stopped. (SeeFIG. 25B). As additional distal-oriented force is applied to the mechanism200, the wire forms214are caused to bow radially outward within the valve30to cause the upper panel36to fully deploy, as shown inFIG. 25C. The mechanism200is then collapsed and retracted proximally.

Turning toFIGS. 26A-E, several alternative balloon-based active deployment mechanism are described. The balloon-based systems include use of a balloon or other expandable member to cause an otherwise non-fully deployed valve30to expand to its fully expanded state upon deployment. Preferably, each of the balloons described herein includes an inflation lumen that is communicatively connected to the handle mechanism102or otherwise provided with a mechanism for selectively inflating the balloon(s) as needed.

FIG. 26Aillustrates a first embodiment in which a balloon220is provided internally of a prosthetic valve30. The balloon220includes a pair of broad portions222athat correspond with the proximal and distal ends of the valve30, and a narrowed waist portion222bthat corresponds with the middle portion of the valve30. The balloon220may optionally be provided in a fixed relationship with the valve body, as illustrated inFIG. 26B, wherein the balloon220is packaged with the valve30as the valve30is loaded into the delivery catheter and delivered to a treatment location. Thus, if the valve30is found not to have fully expanded after deployment, the balloon220may be inflated to cause full deployment.

A number of optional balloon shapes and sizes are illustrated inFIGS. 26C-E. For example, inFIG. 26C, a single balloon220is shown having two large diameter portions222aand a narrow, or smaller diameter portion222bconnecting the other two portions. InFIG. 26D, a single balloon220is shown, and would preferably extend through the entire length of the valve30. InFIG. 26E, three separate balloons220a-care illustrated in an offset-tangent arrangement. The offset-tangent arrangement provides a number of benefits, including the ability to selectively inflate only one or more of the balloons220a-cdepending upon which valve panel36requires expansion. Also, the offset-tangent arrangement removes the need to fully occlude the vessel, thereby allowing fluid to flow around the balloon structure.

Turning toFIGS. 27A-B, in another alternative arrangement, a pair of toroidal balloons226are attached to the external surface of a prosthetic valve30near its proximal and distal ends, respectively. The pair of toroidal balloons226may be selectively expandable in order to actively deploy an otherwise non-fully deployed prosthetic valve30. Upon expansion of the valve, the balloons226may then be deflated and left in place to serve as a seal against the vessel wall230, as shown inFIG. 27B. Alternatively, the toroidal balloons226may be attached to the internal wall of the prosthetic valve30, and may then be selectively detached from the valve30after the valve has been fully deployed.

FIG. 28illustrates another active deployment mechanism234that includes a roller member236and a pincher member238, each of which may be included on the distal end of a shaft that may be included with, or separate from, the delivery catheter100. The roller236and pincher238advance along a panel36until the components encounter a hinge52. Because of the diameter of the roller236relative to the hinge52, when the roller236and pincher238engage the hinge52, they force the hinge52to open, thereby causing the valve panel36to fully deploy.

FIGS. 29A-Billustrate yet another deployment mechanism242that includes a wedge-shaped member having an upper guide244and a lower separator246. As with the previous deployment mechanism234, the present embodiment242be included on the distal end of a shaft that may be included with, or separate from, the delivery catheter100. The wedge mechanism242is intended to be guided onto each of the hinges52of the undeployed or not-fully deployed valve30. Because of the relative size and shape of the separator246portion of the wedge, the separator246causes the hinges52to open, thereby causing the valve panels36to expand to the fully deployed state.

Turning next toFIG. 30, another deployment mechanism250includes a torsion spring252mounted to the internal surface of the valve30. The torsion spring252may be integrated into and/or may form part of the hinge52of the valve30, but is provided with a pair of arms254that extend into the interior of the valve30, and which are biased to force the valve panels36radially outward to fully deploy the valve30. The torsion spring252may be formed integrally with the valve30, in which case it remains in place after valve deployment.

Turning toFIGS. 31A-B, yet another active valve deployment mechanism256includes a membrane balloon258formed on or attached to the external surface of each of the longitudinal members180of the slotted tube110. The membrane balloons258are selectively and independently inflatable, as needed to actively deploy one or more undeployed panels of a prosthetic valve30. As shown inFIG. 31A, the slotted tube110is first inserted into the valve30, then one or more of the membrane balloons258is expanded. The expansion is initially to a first state260in which the membrane balloon engages the valve body panels36, then, ultimately, to a second state262corresponding with full valve deployment. After deployment, the balloon may be deflated and the device removed from the patient's vasculature.

Turning toFIG. 32, a still further alternative active valve deployment mechanism266includes a plurality of (preferably three) linkage members268, each including a pivot270allowing the linkage member to expand radially, such as under the expansion force of an internal balloon272or other expandable member. Thus, as the deployment mechanism266is inserted into the undeployed prosthetic valve30, it is able to be expanded by expanding or inflating the balloon272.

FIGS. 33A-Billustrate another active deployment mechanism276that incorporates a balloon278or other expandable member that is formed within the internal volume of the nosecone118. In its undeployed state, shown inFIG. 33A, the balloon278does not extend past the distal end of the nosecone118. However, if needed to expand the undeployed or not-fully deployed valve30, the balloon278is expanded, as shown inFIG. 33B, thereby expanding the valve30to its expanded state.

FIGS. 34A-Cillustrate an active deployment mechanism that includes a yoke282that is slidably engaged over the nosecone shaft136. A set of rotating linkages284a-fare connected to the sliding yoke282such that, when the yoke282slides proximally along the nosecone shaft136, as shown by the arrows “A” inFIG. 34A, the linkages284a-fextend radially outward from the shaft136. In the preferred embodiment, the free ends284d-fof each of the linkages284a-fare selectively attached to a respective panel of the valve30by a temporary mechanism. For example, the free ends284d-fof the linkages may be attached to the valve panels by the tethers124, such that when the tethers124are retracted, the valve panels are released from the linkages284a-f. The nosecone118is preferably hollow to accommodate the mechanism prior to deployment.

Another optional active deployment mechanism utilizes the shape set nosecone shaft136and tensioning member336shown inFIGS. 23A-C. In the case of a valve30that does not fully deploy, it may be possible to manipulate the tensioning member336to cause either the nosecone118, the nosecone shaft136, or some other portion of the deployment mechanism104to engage the undeployed portion of the valve sufficiently to cause it to fully deploy. In a particularly preferred method, the tethers124associated with all of the fully deployed panels are allowed to remain slack, while the tether124associated with the undeployed panel is pulled taut to apply tension to the tether. By doing so, the nosecone118and the respective wrapping pin130are pulled to the respective distal and proximal edges of the valve panel, creating a relatively rigid linkage between the components. Once this is done, the tensioning member336(or other suitable steering mechanism) is actuated in order to cause the relatively rigid linkage to bias the still-inverted panel radially outward to the expanded position. This process may be repeated for each panel that is not fully expanded.

Finally, another alternative active deployment mechanism is to pressurize the aorta (or other treatment vessel) to cause the tissue defining the vessel to expand, thereby providing an adequate (increased) volume within which the valve30or other device is able to expand to its fully expanded state. Pressurization of the aorta (or other vessel) may be obtained by simply occluding the vessel, or by actively pressuring the vessel using an external source.

The preferred embodiments of the inventions that are the subject of this application are described above in detail for the purpose of setting forth a complete disclosure and for the sake of explanation and clarity. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure. Such alternatives, additions, modifications, and improvements may be made without departing from the scope of the present inventions, which is defined by the claims.