Aortic root replacement with a novel decellularized cryopreserved aortic homograft: Postoperative immunoreactivity and early results

Objective: Novel antigen-reduction SynerGraft technology (CryoLife Inc, Kennesaw, Ga) reduces the cellular components of a cadaver homograft with an enzymatic and washing process, leaving the extracellular matrix intact. We report the immunoreactivity (positive panel reactive antibody assay) and early operative results of the CryoLife SynerGraft aortic valve conduit homograft. Methods: Twenty-two patients (age 53 ± 14 years, range 31-80 years) from April 2002 to July 2003 underwent aortic root replacement with a CryoLife SynerGraft aortic valve conduit homograft (CryoLife Inc, Kennesaw, Ga) for congenital or acquired aortic valve disease, aortic aneurysm with aortic valve disease, or native or prosthetic aortic valve endocarditis. Baseline percentage positive panel reactive antibody results were negative (<10%) for all and were assessed at 1 month, 3 months, and 1-year. Homograft function was evaluated by echocardiography. Results: Early mortality was 0%. Two late deaths at 1 postoperative year were unrelated to homograft function. At 1 postoperative month, panel reactive antibody results were negative in 20 patients (91%). At 3 months, 19 of 22 patients (86%) had negative results, including 1 with previous positive results. At 1 year, 19 of 20 patients (95%) had negative results, including 2 of the 3 with previous positive results. The mean aortic valve gradients were 12 ± 8 mm Hg (n = 21) at discharge and 11 ± 7 mm Hg (n = 18) at 1 year. At a mean follow-up of 30.3 ± 5.2 months, the mean gradient was 8.8 ± 6.3 mm Hg. Conclusion: The SynerGraft decellularization technology successfully removed antigens from an aortic valve homograft conduit. Aortic root reconstruction with the CryoLife SynerGraft aortic valve homograft resulted in low transvalvular gradients, similar to those seen with standard cryopreserved homografts. These early results suggest an advancement in homograft technology. The low panel reactive antibody response may enhance durability by eliminating immune complex-mediated reaction against the homograft. The lack of allosensitization in patients who may require organ transplantation in the future is an added benefit.