Aortic Root Replacement with Decellularized Aortic Valve Allografts: 10 Years of Experience of a Pioneer Series

Background: Decellularization is a technology intended to reduce tissue antigenicity and improve outcomes after allograft valve replacement. Although experimental results were very promising, long-term clinical results are unknown. The purpose of this study is to demonstrate clinical outcomes of AVR with decellularized aortic valve allografts up to 10 years of follow-up.

Methods: From November 2005 to August 2017, a total of 115 high-risk patients had AVR with decellularized aortic valve allografts as a root replacement. Decellularization was performed with sodium dodecyl sulfate (SDS) 0.1%. Mean age was 45 ± 18 years and 77 were males. More than half had associated concomitant procedures or active bacterial endocarditis. Mean allograft diameter was 22 ± 1.7 mm. Besides routine clinical and echocardiographic evaluation, patients were also studied with CT scan and MRI studies. Clinical follow-up was available in 93% of the patients and mean follow-up time was 5.1 years.

Results: Early mortality was 6% and late survival was 75% at 10 years. There were no cases of thromboembolism, but one hemorrhagic stroke. Peak gradients were low and stable, with an early mean peak gradient of 9.9 ± 7.8 mm Hg and 9.1 ± 9.2 mm Hg at the latest follow-up. Two patients developed moderate AR, one due to primary cusp prolapse and the other due to healed bacterial endocarditis. Freedom from allograft dysfunction was 94% at 10 years. Three patients were reoperated, two due to AR and one because the patient outgrew the allograft diameter. Freedom from reoperation was 94% at 10 years. By CT scan, calcium scores of the allograft root had slight elevations over time. Also, allografts diameters were stable over time at the annulus, sinus of Valsalva and sinotubular junction levels, with no case of allograft dilatation. Two explanted allografts demonstrated good tissue integrity, with partial repopulation and no signs of gross calcification.

Conclusion: Decellularized aortic valve allografts have shown excellent hemodynamics and low incidence of SVD up to 10 years of follow-up. Although longer follow-up is necessary, these results suggest that decellularized aortic allografts may be superior and advantageous to conventional cryopreserved allografts.