Dr. Frederic Heim
Universite de Haute Alsace
Heart valve prostheses from textiles
Calcific aortic stenosis is the most common valvular disease observed in Western countries. Worldwide, aortic valve replacement represents today around 250,000 cases and that number is expected to increase by 5 % per year over the coming years. From a survival rate point of view, surgical valve therapy has an enviable track record. The mortality rate for aortic valve replacement is around 5 % which remains globally low and this shows that heart valve surgery is a sustainable technology. Among the patients who are suffering from this ailment, however, 10 % are considered high risk and approximately 15% declined for replacement/repair surgery by the physicians. For these inoperable valvular diseases, percutaneous or non invasive surgery would be a logical solution. The strength of a percutaneous procedure lies in its ability to deliver the device into position through the vascular system without having to conduct the open heart surgery. Hence this approach in which patients are not exposed to the risks of surgery is highly suitable for critical patients. The rapid developments and success in percutaneous vascular stents implantation over the last 2 decades has made this technique attractive today even for the potential aortic valve replacement. For percutaneous insertion of valve, a valve stent will need to be configured. The valve should be constructed of a material that will allow the whole assembly to be appropriately folded to the required small size in order to be snaked through the vascular system and, once deployed in position at the site, function as expected for long term service in vivo.
The goal of the lecture will be to show that textiles are suitable materials for heart valve replacement. The presentation gives some general information about heart valves, how they work, how the valve tissues behave under stress, and how they degrade over time. The currently available replacement solutions are described with a focus on the limits of the commercially available devices. The potential benefits of using an altogether a textile prostheses are mentioned. The textile heart valve prototypes obtained in our lab along with the results from some in vitro tests conducted under the physiological condition are shown. Results obtained in vitro with a textile valve associated with a stent are also presented.