Background. Aortic root replacement with cryopreserved allografts is associated with excellent hemodynamics, little endocarditis, low thromboembolic event rates, and no need for anticoagulation. There is, however, concern regarding the long-term durability of this valve substitute, especially in younger patients. Meta-analysis and microsimulation were used to calculate age-specific long-term prognosis after allograft aortic root replacement based on current evidence. Methods. Our center's experience with cryopreserved allograft aortic root replacement in 165 adult patients was combined in a meta-analysis with reported and individual results from four other hospitals. Using this information, the microsimulation model predicted age- and gender-specific total and reoperation-free and event-free life expectancy. Results. The pooled results comprised 629 patients with a total follow-up of 1860 patient-years (range 0 to 12.8 years). Annual risks were 0.6% for thromboembolism, 0.05% for bleeding, 0.5% for endocarditis, and 0.5% for nonstructural valve failure. Structural allograft failure requiring reoperation occurred in 15 patients, and a patient age-specific Weibull function was constructed accordingly. Calculated total life expectancy varied from 27 years in a 25-year-old to 12 years in a 65-year-old male; corresponding actual lifetime risk of reoperation was 89% and 35%, respectively. Conclusions. Cryopreserved aortic allografts have an age-related limited durability. This results in a considerable lifetime risk of reoperation, especially in young patients. The combination of meta-analysis and micro-simulation provides an appropriate tool for estimating individualized long-term outcome after aortic valve replacement and can be useful both for patient counseling and prognostic research purposes.,
The Annals of Thoracic Surgery
Department of Cardio-Thoracic Surgery

Takkenberg, H., Eijkemans, R., van Herwerden, L., Steyerberg, E., Lane, M., Elkins, R., … Bogers, A. (2003). Prognosis after aortic root replacement with cryopreserved allografts in adults. The Annals of Thoracic Surgery, 75(5), 1482–1489. doi:10.1016/S0003-4975(02)04722-7