Endothelialized biological heart valve prostheses in the non-human primate model

Abstract

OBJECTIVE: The main disadvantage of implanted cardiac valvebioprostheses remains primarily tissue failure due to calcification.Coating of bioprostheses with viable autologous endothelial cells may delayor even eliminate tissue calcification and subsequent cardiac dysfunction.METHODS: Glutaraldehyde-preserved Hancock bioprostheses (n = 5), pretreatedwith glutamic acid (8%) and cryopreserved allografts (n = 5) were lined,using endothelial cells harvested from the external jugular vein. Coatedspecimens were cultivated for 9 days in Medium 199 supplemented with 20%fetal calf serum and basic fibroblast growth factor. Endothelialized graftswere anastomosed into the descending thoracal aorta of adult Chacmababoons. Untreated valve bioprostheses (n = 4) served as controls. Fortydays after implantation the prostheses were examined morphologically andimmunohistochemically. RESULTS: After implantation endothelializedprostheses showed a positive Factor VIII related antigen reaction byimmunohistochemistry on all valve surfaces. Scanning electron microscopyshowed confluently lined leaflets with transplanted endothelial cells anddisplayed cobblestone morphology on all coated allografts. In contrast, thesurface of pretreated xenograft valves revealed uncoated areas withplatelet and leucocyte aggregates. No endothelium was observed on theleaflets of untreated controls 40 days after implantation. CONCLUSION: Invitro endothelialization of cardiac valve bioprostheses with autologousendothelial cells is possible. The newly created endothelium is shearstress resistant and the antithrombotic as well as the antiaggregatorycapacity of the transplanted cells were retained. Lining with autologousendothelial cells could improve the durability and clinical outcome ofbiological valve prostheses.