61.04 Late Durability of Decellularized Allografts for Aortic Valve Replacement: a Word of Caution

M. R. Helder1, N. T. Kouchoukos4, K. Zehr2, J. A. Dearani1, C. N. Heins3, H. V. Schaff1 1Mayo Clinic,Cardiovascular Surgery,Rochester, MN, USA 2Johns Hopkins University School Of Medicine,The John Hopkins Heart & Vascular Institute,Baltimore, MD, USA 3Mayo Clinic,Biomedical Statistics And Informatics,Rochester, MN, USA 4Missouri Baptist Medical Center,St. Louis, MO, USA

Introduction: Decellularized bioprostheses utilized for aortic valve replacement (AVR) have the theoretical advantage of reduced antigenicity and increased durability. Prior studies demonstrated satisfactory early outcome and negative panel reactive antibody in >90% of pt with DAVA 1 year postoperatively. However, long-term durability of DAVA is unknown.

Methods: We reviewed 42 consecutive pt who underwent AVR with a decellularized allograft from March 12, 2002 to October 6, 2004 at 2 institutions. We compared this cohort to 29 consecutive control pt who underwent AVR with a standard cryopreserved allograft during the same interval. The primary outcome was aortic valve reoperation, and secondary outcome was overall mortality.

Results:In pt undergoing AVR with DAVA, aortic reoperation was required in 37% (15/41) of survivors, and the most common indication was allograft regurgitation (7/15, 47%). In the 29 control pt receiving standard cryopreserved allografts, aortic valve reoperation was required in 17% (4/24), and aortic regurgitation was the indication in 2 (50%). Freedom from reoperation 5 yr postoperatively was 92% (95% CI, 84%-100%) in the DAVA group compared to 100% in the control group. Freedom from reoperation at 10 yr postoperatively was 51% (95% CI, 34%-76%) in pt receiving DAVA compared to 80% (95% CI, 60%-100%) in the control group (p=0.06). Overall 5 and 10-yr survival were 90% (95% CI, 80%-100%) and 76% (95% CI, 61%-93%) in the decellularized group compared the 72% (95% CI, 57%-90%) and 57% (95% CI, 38%-79%) in the control group (p=0.09).

Conclusion: Late survival of pt receiving DAVA was similar to that of pt with standard cryopreserved allografts. This study identified a strong trend for late allograft deterioration and reoperation beyond 5 yr postoperatively in the DAVA group. These findings should be considered when designing clinical trials of tissue-engineered bioprostheses.