BACKGROUND

The present disclosure relates to systems, devices, and methods for percutaneous implantation of a prosthetic heart valve. More particularly, it relates to systems, devices, and methods for percutaneously remodeling an implanted stented prosthetic heart valve.

Diseased or otherwise deficient heart valves can be repaired or replaced with an implanted prosthetic heart valve. Conventionally, heart valve replacement surgery is an open-heart procedure conducted under general anesthesia, during which the heart is stopped and blood flow is controlled by a heart-lung bypass machine. Traditional open surgery inflicts significant patient trauma and discomfort, and exposes the patient to a number of potential risks, such as infection, stroke, renal failure, and adverse effects associated with the use of the heart-lung bypass machine, for example.

Due to the drawbacks of open-heart surgical procedures, there has been an increased interest in minimally invasive and percutaneous replacement of cardiac valves. With percutaneous transcatheter (or transluminal) techniques, a valve prosthesis is compacted for delivery in a catheter and then advanced, for example, through an opening in the femoral artery and through the descending aorta to the heart, where the prosthesis is then deployed in the annulus of the valve to be replaced (e.g., the aortic valve annulus). Although transcatheter techniques have attained widespread acceptance with respect to the delivery of conventional stents to restore vessel patency, only mixed results have been realized with percutaneous delivery of the more complex prosthetic heart valve.

Various types and configurations of prosthetic heart valves are available for percutaneous valve procedures, and continue to be refined. The actual shape and configuration of any particular transcatheter prosthetic heart valve is dependent to some extent upon the native shape and size of the valve being repaired (i.e., mitral valve, tricuspid valve, aortic valve, or pulmonary valve). In general, prosthetic heart valve designs attempt to replicate the functions of the valve being replaced and thus will include valve leaflet-like structures. With a bioprostheses construction, the replacement valve may include a valved vein segment that is mounted in some manner within an expandable stent frame to make a valved stent (or “stented prosthetic heart valve”). For many percutaneous delivery and implantation devices, the stent frame of the valved stent is made of a self-expanding material and construction. With these devices, the valved stent is crimped down to a desired size and held in that compressed arrangement within an outer sheath, for example. Retracting the sheath from the valved stent allows the stent to self-expand to a larger diameter, such as when the valved stent is in a desired position within a patient. In other percutaneous implantation systems, the valved stent can be initially provided in an expanded or uncrimped condition, then crimped or compressed on a balloon portion of a catheter until it is as close to the diameter of the catheter as possible. Once delivered to the implantation site, the balloon is inflated to deploy the prosthesis. With either of these types of percutaneous stented valve delivery devices, conventional sewing of the prosthetic heart valve to the patient's native tissue is typically not necessary.

With transcatheter delivery, it is imperative that the stented prosthetic heart valve be accurately located relative to the native annulus immediately prior to full deployment from the catheter as successful implantation requires the prosthetic heart valve to intimately lodge and seal against the native annulus. If the prosthesis is incorrectly positioned relative to the native annulus, serious complications can result such as leaks or even dislodgement from the native valve implantation site. Further, even if optimally located, problems may arise if the implanted prosthesis does not closely “fit” the native anatomy, including paravalvular leakage, migration due to hydrodynamic forces, and damage to surrounding tissues (e.g., aorta, cardiac tissue, etc.). As a point of reference, these same concerns do not normally arise in the context of conventional vascular stent implantation; with these procedures, the stent will perform its intended function regardless of whether the expanded shape closely matches the native anatomy.

In light of the above concerns, a clinician may employ imaging technology to evaluate the native heart valve anatomy prior to performing the implantation procedure, selecting an optimally sized prosthesis based on the evaluation. However, only the size of the selected prosthesis is affected by this evaluation, and not the overall shape. Thus, while the differently sized transcatheter prosthetic heart valves made available to the clinician are generally shaped in accordance with the expected native valve anatomy, it is unlikely that a selected prosthesis will actually “match” the actual native shape. Further, there are significant limitations associated with current imaging-based sizing procedures for transcatheter prosthetic heart valves. For example, measurements are currently only taken in one or two dimensional views and therefore may not account for annular ellipticity; identifying the true leaflet basal hinge point can be difficult with calcification, imaging errors, and the non-orthogonal geometry of a tricuspid valve; unknown annular compliance makes cross-sectional geometry of an implanted stent frame difficult to predict, which can lead to unacceptable stent aspect ratios and replacement valve performance; and variable calcification profiles may interact unpredictably with the stent frame. Unfortunately, conventional transcatheter prosthetic heart valve implantation devices do not readily permit in situ remodeling or shaping of a deployed heart valve prosthesis.

In light of the above, a need exists for transcatheter prosthetic heart valve delivery systems and methods that facilitate modeling of an implanted prosthesis to the native valve anatomy.

SUMMARY

Some aspects in accordance with principles of the present disclosure relate to a method of restoring (e.g., replacing) a defective heart valve of a patient. The method includes manipulating a delivery device to percutaneously deliver a stented prosthetic heart valve in a compressed arrangement to an implantation site of the defective heart valve. The stented prosthetic heart valve includes a stent frame to which a valve structure is attached, with the stent frame being configured to radially self-expand from the compressed arrangement. The delivery device is operated to release the stented prosthetic heart valve, including permitting the stent frame to self-expand from the compressed arrangement toward a deployed arrangement in which the prosthesis is implanted within the defective heart valve in an initial state. A post-dilatation balloon is percutaneously delivered, in a deflated state, to the implantation site. A compliant segment of the balloon is arranged within a region of the implanted stented prosthetic heart valve for which remodeling is desired. The balloon is then inflated such that the compliant segment expands and contacts the implanted stented prosthetic heart valve in the remodeling region. The remodeling region is expanded from the initial state via continued inflation of the compliant segment to alter a shape of the implanted prosthetic heart valve to a remodeled state. In some embodiments, the method includes directing the delivery device through a catheter to deliver the compressed prosthesis to the implantation site, followed by removal of the delivery device and subsequent insertion of the balloon through the catheter. In other embodiments, the implanted prosthetic heart valve defines an inflow side and an outflow side, with the compliant segment contacting the stent frame at a location between the inflow and outflow sides. In related embodiments, the balloon further includes first and second segments at immediately opposite sides of the compliant segment, respectively, with the first and second segments expanding to a predetermined maximum outer diameter while the compliant segment increases in maximum outer diameter with continued inflation of the balloon. With these and related techniques, remodeling of an implanted, stented prosthetic heart valve to better match the native shape is possible, providing many benefits such as reducing the risk of paravalvular leaks, optimal valve hydrodynamic performance, and durability.

Other aspects in accordance with principles of the present disclosure relate to a system for percutaneously restoring (e.g., replacing) a native heart valve of a patient. The system includes a stented prosthetic heart valve, a delivery device, and a post-dilatation balloon assembly. The stented prosthetic heart valve has a stent frame to which a valve structure is attached. The stent frame is configured to radially self-expand from a compressed arrangement. The delivery device includes a delivery sheath sized for percutaneously accessing a native heart valve. The delivery device provides a delivery state in which the delivery sheath compressively maintains the stented prosthetic heart valve in the compressed arrangement, as well as a deployment state in which the delivery sheath is withdrawn from the stented prosthetic heart valve to permit the prosthesis to self-expand from the compressed arrangement to a normal, expanded arrangement. The post-dilatation balloon assembly includes a catheter and a balloon fluidly attached to the catheter. The balloon is sized for percutaneously accessing the stented prosthetic heart valve once implanted to the native heart valve. In this regard, the balloon includes a compliant segment having a longitudinal length that is less than a longitudinal length of the prosthetic heart valve. Further, a maximum outer diameter of the compliant segment continuously expands with continuous inflation of the balloon. In some embodiments, the compliant segment has, in an inflated state of the balloon, an obround shape in longitudinal cross-section. In other embodiments, the balloon further defines first and second segments at immediately opposite sides of the compliant segment, respectively, with the first and second segments being less compliant than the compliant segment. In related embodiments, a wall thickness of the balloon along the compliant segment is less than a wall thickness of the balloon along the first and second segments.

