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Method and apparatus for replacing a prosthetic valve

Method and apparatus for replacing a prosthetic valve description/claims

The present invention relates to embodiments of a method and apparatus for replacing a previously implanted prosthetic valve, such as a surgically implanted prosthetic heart valve, without removing the previously implanted valve from the body.

Prosthetic valves, such as prosthetic heart valves, are implanted in the body to replace a failing or diseased natural valve. Should the prosthetic valve begin to fail, it also may need to be replaced with another prosthetic valve. Surgically implanted, prosthetic heart valves, such as a prosthetic aortic valve, typically are replaced about every 15 years. The current method for replacing a surgically implanted, prosthetic heart valve involves open heart surgery wherein the patient's chest is opened and the existing prosthetic valve is removed and replaced with a new prosthetic valve. As can be appreciated, this is a traumatic and high risk procedure accompanied by substantial morbidity and mortality, and in some cases, cannot even be attempted due to the advanced age and/or medical condition of the patient.

Therefore, it would be preferable to replace a prosthetic heart valve with a percutaneously implanted valve that is delivered to the implantation site via the patient's vasculature and deployed within the previously implanted valve. However, because existing prosthetic heart valves can vary widely in size and shape, there are substantial difficulties associated with the development and validation of a percutaneously delivered replacement valve that is compatible with different types of existing prosthetic heart valves. More particularly, difficulties arise because a replacement valve that does not conform to the geometry of the previously implanted valve may not be able to adequately anchor to the previously implanted valve and/or form an effective seal with the previously implanted valve.

In one aspect, the present disclosure concerns a percutaneously delivered adapter stent that is deployed within a previously implanted prosthetic valve and serves as an anchor or platform for implanting a percutaneously delivered replacement valve within the previously implanted valve. The replacement valve can be any known percutaneous valve. The adapter stent can be adapted to provide a suitable mounting platform for implanting a percutaneous replacement valve in a wide range of existing surgical valves, which typically vary widely in size and shape from patient to patient. In one advantageous feature, the adapter stent increases the frictional forces between the percutaneous replacement valve and the failing surgical valve, thereby providing a more predictable orientation and securement of the percutaneous replacement valve. Hence, this technique is particularly suited for replacing a surgically implanted prosthetic heart valve, but also could be used for replacing a percutaneously implanted prosthetic valve.

The adapter stent can be delivered to the implantation site via the patient's vasculature and positioned within the previously implanted valve. The stent can then be deployed to cause the stent to expand and become anchored to the inner surface of the previously implanted valve. Subsequently, the replacement valve can be positioned within the adapter stent and deployed to cause the replacement valve to expand and become anchored to the adapter stent.

In particular embodiments, the adapter stent and the replacement valve can be mounted on the same delivery catheter for delivery to the implantation site. In one implementation, for example, the adapter stent and the replacement valve can be crimped around respective first and second balloons of a double-balloon catheter. In this approach, the adapter stent is positioned in the previously implanted valve and expanded into contact with the previously implanted valve by inflating the first balloon. The catheter is then repositioned to place the replacement valve in the deployed adapter stent, after which the valve is expanded into contact with the adapter stent by inflating the second balloon. In another implementation, the adapter stent and the replacement valve are self-expandable. The self-expandable adapter stent and valve can be mounted on a common delivery catheter adapted to retain the stent and the valve in compressed positions while they are advanced through the patient's vasculature. Using the catheter, the adapter stent and the valve can be successively positioned and deployed within the previously implanted valve.

The adapter stent in exemplary embodiments can comprise an expandable frame that mounts a flexible annular sealing member. The sealing member provides a seal between the previously implanted valve and the replacement valve to prevent or at least minimize blood flow between the original and replacement valves.

The adapter stent may be configured to have a length that is greater than the length of the previously implanted valve that needs to be replaced. This allows the stent to extend over the entire inner surface of the previously implanted valve to provide sufficient surface area for anchoring the replacement valve and to ensure that the previously implanted valve does not interfere with the positioning and deployment of the replacement valve. In certain embodiments, the adapter stent, when expanded, has enlarged end portions that flare or extend radially outwardly past the adjacent ends of the previously implanted valve to assist in securing the adapter stent in place.

In one representative embodiment, a method is provided for percutaneously implanting a replacement prosthetic valve at a site occupied by a previously implanted prosthetic valve. The method includes positioning an adapter stent within the previously implanted valve, deploying the adapter stent to cause the adapter stent to become anchored to the previously implanted valve, positioning the replacement valve within the deployed adapter stent, and deploying the replacement valve to cause the replacement valve to become anchored to the adapter stent.

In another representative embodiment, a method of percutaneously implanting a replacement prosthetic valve in a patient at a site occupied by a previously implanted prosthetic valve includes advancing a catheter carrying an adapter stent through the patient's vasculature to position the adapter stent within the previously implanted valve. The catheter also carries the replacement valve. The method further includes deploying the adapter stent to cause the adapter stent to become anchored to the previously implanted valve, repositioning the catheter to position the replacement valve within the deployed adapter stent, and deploying the replacement valve to cause the replacement valve to become anchored to the adapter stent.

In another representative embodiment, an assembly is provided for percutaneous replacement of a previously implanted prosthetic valve without removal of the previously implanted valve. The assembly comprises an adapter stent comprising a frame and an annular sealing member. The adapter stent is adapted to be deployed within the previously implanted valve. The assembly also includes a percutaneous, replacement prosthetic valve comprising a frame and a flexible valve member. The valve is adapted to be deployed within the deployed adapter stent such that the sealing member provides a seal between the previously implanted valve and the replacement valve.

In yet another representative embodiment, an assembly for percutaneous replacement of a previously implanted prosthetic valve comprises a percutaneous, replacement prosthetic valve comprising a frame and a flexible valve member. The assembly also includes means for anchoring and sealing the replacement valve to the previously implanted valve, said means being separately deployable within the previously implanted valve prior to deploying the replacement valve within said means.

The foregoing and other features and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

FIG. 1 is a side elevation view of one embodiment of an assembly comprising a percutaneous prosthetic valve and an adapter stent for anchoring the prosthetic valve within a previously implanted prosthetic valve.

FIG. 2 is a perspective view of the prosthetic valve shown in FIG. 1.

FIG. 3 is a schematic side view of an embodiment of a double-balloon catheter showing the prosthetic valve and the adapter stent of FIG. 1 crimped around respective balloons on the catheter for percutaneous delivery to an implantation site.

• Provisional Patent
• Utility Patent

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