First Closed-Heart Surgery Using a Nitinol Stent

Researchers at the Centre Hospitalier Universitaire de Saint-Étienne (France) have reported the first successful TEAVR procedure, which has not been feasible previously because of the currently available designs of stented tissue valves. The two patients, aged 82 and 93 years of age, suffered from aortic valve stenosis. In all, the patients spent about two and a half hours under cardiopulmonary bypass, but the actual implantation of the device took only 45 minutes. Both patients were discharged from the hospital in a week and have had no serious complications since.

The new procedure may enable surgeons to replace the aortic valve without opening the chest, though it will still require cardiopulmonary bypass and excision of the old valve. The key to the new procedure is the recent availability of sutureless aortic valve bioprostheses, in this case the 3f Enable bioprosthesis, which is mounted on a compressible self-expanding nitinol stent. Sutureless substitutes are not yet available for the other cardiac valves, such as the mitral valve. The study describing the new procedure was published in the March 2014 issue of Journal of Thoracic and Cardiovascular Surgery.

“These first procedures show that totally endoscopic sutureless aortic valve replacement is technically feasible,” said lead surgeon Marco Vola, MD. “It is important to note that when performing TEAVR, a quick and safe conversion to minithoracotomy under direct view can be made if circumstances demand. This would still offer significantly reduced chest trauma.”

The 3f Aortic Bioprosthesis, a product of Medtronic (Minneapolis, MN, USA), is composed of three equine pericardial leaflets, shaped in the form of a tube, which collapse in response to pressure, reproducing the functional characteristics of a native aortic valve. The design preserves aortic sinuses by maintaining continuity between the annulus and the sinotubular junction, without the need for a second suture line. The greatest stress is toward the semilunar “belly” of the cusps, as observed in healthy aortic valves.

The aortic valve is the outlet valve from the left ventricle and usually requires repair or replacement when it either does not open completely, or does not close properly, and therefore blood leaks back into the left ventricle. The symptoms most often associated with aortic valve disease are shortness of breath, chest pain, fatigue, arrhythmias, palpitations, and syncope usually associated with exertion.

Related Links:
Centre Hospitalier Universitaire de Saint-Étienne
Medtronic