In vivo functional performance and structural maturation of decellularised allogenic aortic valves in the subcoronary position

Objective Successful animal and clinical implantation of decellularised heart valves has been performed in the pulmonary position Comparable results have not yet been achieved for the aortic position with the high haemodynamic demands of the systemic circulation and the challenging implantation procedure Methods Allogenic aortic valves (n = 10) were decellularised using detergents (decellularised aortic valves (dAoVs)) Five prostheses were analysed for decellularisation quality and scaffold preservation Five valves were orthotopically implanted in juvenile sheep in a subcoronary technique After 5 months, echocardiography, immunohistology histology, electron microscopy and western blot (WB) were used for analysis Results All animals survived the follow up with increased body weight (38 8 +/- 2 8 kg vs 56 0 +/- 2 6 kg p < 0 001) After implantation, three dAoVs showed negligible and two others minor insufficiency (I), which remained unchanged at explantation Effective orifice area increased slightly (1 1 +/- 0 2 cm(2) vs 1 6 +/- 0 3 cm(2), p = 0 051) Explanted dAoVs (n = 4) showed excellent macroscopy with minor soft tissue nodules observed at the free cusp margins of only one dAoV No valve showed any signs of thrombosis or calcification On microscopic evaluation, the cusp architecture was preserved with an almost complete endothelial repopulation as confirmed by vimentin(+)/von Willebrand factor (vWF(+)) staining, WB of endothelial markers (eNOS/vWF) and scanning electron microscopy (SEM) Partial interstitial reseeding with vimentin(+)/alpha smooth muscle (alpha sm(+)) cells was noted Quantitative measurement of collagen IV, collagen I laminin and elastin (WB) demonstrated preserved scaffold composition as compared to native tissue Conclusion The dAoVs showed excellent functional outcome at 5 months in a subcoronary model of juvenile sheep Advanced endothelial and nascent interstitial repopulation, with preserved structural integrity under the high shear stress milieu of the aortic valve, encourage further long term studies (C) 2010 European Association for Cardio Thoracic Surgery Published by Elsevier B V All nghts reserved