Allografts for aortic valve or root replacement: insights from an 18-year single-center prospective follow-up study
Objective: Whether allografts are the biological valve of choice for AVR in non-elderly patients remains a topic of debate. In this light we analyzed our ongoing prospective allograft AVR cohort and compared allograft durability with other biological aortic valve substitutes. Methods: Between April 1987 and October 2005, 336 patients underwent 346 allograft AVRs (95 subcoronary, 251 root replacement). Patient and perioperative characteristics, cumulative survival, freedom from reoperation, and valve-related events were analyzed. Using microsimulation, for adult patients, age-matched actual freedom from allograft reoperation was compared to porcine and pericardial bioprostheses. Results: Mean age was 45 years (range 1 month to 83 years); 72% were males. Etiology was mainly endocarditis 32% (active 22%), congenital 31%, degenerative 9%, and aneurysm/dissection 12%. Twenty-seven percent underwent prior cardiac surgery. Hospital mortality was 5.5% (N = 19). During follow-up (mean 7.4 years, maximum 18.5 years, 98% complete), 54 patients died; there were 57 valve-related reoperations (3 early technical, 11 non-structural, 39 structural valve deterioration (SVD), 4 endocarditis), 5 cerebrovascular accidents, 1 fatal bleeding, 8 endocarditis. Twelve-year cumulative survival was 71% (SE 3), freedom from reoperation for SVD 77% (SE 4); younger patient age was associated with increased SVD rates. Actual risk of allograft reoperation was comparable to porcine and pericardial bioprostheses in a simulated age-matched population. Conclusions: The use of allografts for AVR is associated with low occurrence rates of most valve-related events, but over time the risk of SVD increases, comparable to stented xenografts. It remains in our institute the preferred valve substitute only for patients with active aortic root endocarditis and for patients in whom anticoagulation should be avoided.