The present invention is related to prosthetic heart valve replacement, and more particularly to systems and methods for simulated deployment of prosthetic heart valves.
Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery.
Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve must first be collapsed or crimped to reduce its circumferential size.
When a collapsed prosthetic valve has reached the desired implant site in the patient (e.g., at or near the annulus of the patient's heart valve that is to be replaced by the prosthetic valve), the prosthetic valve can be deployed or released from the delivery apparatus and re-expanded to full operating size. For balloon-expandable valves, this generally involves releasing the entire valve, assuring its proper location, and then expanding a balloon positioned within the valve stent. For self-expanding valves, on the other hand, the stent automatically expands as the sheath covering the valve is withdrawn. Once a self-expanding valve has been fully deployed, it expands to a diameter larger than that of the sheath that previously contained the valve in the collapsed condition.
Designs of prosthetic heart valves may be tested in simulated environments (e.g., in large animals or in testing equipment) before the designs are used in human patients. Typically, aortic valves are tested in healthy tissue or similar environments, which may not accurately simulate the diseased tissue in which these heart valves are usually implanted in a human. A healthy tissue environment may be more or less resistant to radial expansion than a diseased human aorta, which may result in inaccuracies in the simulated deployment such as prosthetic heart valves migrating away from the installed location in a testing environment.
There therefore is a need for improvements to the devices, systems, and methods for simulated deployment of prosthetic heart valves. Among other advantages, the present invention may address one or more of these needs.