[Aortic Root Replacement with Cryopreserved Allograft Aortic Valve].

Aortic root replacement with a cryopreserved allograft aortic valve is effective for active infectious endocarditis and prosthetic valve endocarditis, especially with a perivalvular abscess, since an allograft seems to be resistant to infection by maintaining viable cells under the process of programmed freezing. From December 1998 to March 2017, aortic root replacement with allograft aortic valves were performed in 38 patients in the University of Tokyo. The in-hospital mortality was 18%, the 5-year survival rate was 68%, and the 5-year freedom rate of reoperation was 75%. Although the clinical outcome was improved as institutional experiences increased recently, pseudoaneurysm during the long-term follow-up period needs special attention. The health-insurance system was applied to this allograft treatment in April 2016 by the Ministry of Health, Labour and Welfare. There are still some hurdles for obtaining institutional certification and financial resources, and enough number of donor allografts, so as to use them more commonly.