title: Comparative study of the L-hydro process and glutaraldehyde preservation.
abstract: Commercial bioprosthetic heart valves are commonly preserved in glutaraldehyde and are cytotoxic to host cells, preventing spontaneous endothelialization. The aim of this study was to demonstrate the potential for in vivo endothelialization of bioprostheses treated by the L-Hydro process which consists of mild extraction of antigenic substances and incorporation of antiinflammatory and antithrombotic agents. Seven stented porcine heart valves treated by the L-Hydro process and 3 glutaraldehyde-fixed porcine heart valves were implanted in the mitral position in juvenile sheep. The valves were evaluated by echocardiography, angiography, histology, and histochemistry. No hemodynamic differences were observed, but scanning and transmission electron microscopy showed nearly complete coverage by endothelial cells of all leaflets in the L-Hydro-treated valves after 5 months of implantation. The endothelial cells were in direct contact with the underlying collagen and expressed von Willebrand-related antigens. The surfaces of the glutaraldehyde-treated valves were covered by fibrin, macrophages, calcium, and thrombotic material; only sparse endothelial cells were observed and contact with the underlying tissue was incomplete. These data indicate that L-Hydro-treated porcine valves are capable of inducing spontaneous endothelialization.
authors.affiliation: The Heart Institute (HC-InCor), University of São Paulo Medical School, São Paulo, Brazil. rvnina@aol.com
authors.forename: Vinicius J S
authors.initials: VJ
authors.lastname: Nina
authors.forename: Pablo M A
authors.initials: PM
authors.lastname: Pomerantzeff
authors.forename: Ivan S J
authors.initials: IS
authors.lastname: Casagrande
authors.forename: David T
authors.initials: DT
authors.lastname: Cheung
authors.forename: Carlos M A
authors.initials: CM
authors.lastname: Brandão
authors.forename: Sérgio A
authors.initials: SA
authors.lastname: Oliveira
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001705:Bioprosthesis; D002114:Calcinosis / Q000473:pathology; D002454:Cell Differentiation; D003094:Collagen / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology; D004730:Endothelium, Vascular / Q000378:metabolism; D005169:Factor VIII / Q000378:metabolism; D005343:Fibrinolytic Agents; D005404:Fixatives; D005976:Glutaral; D006350:Heart Valve Prosthesis; D006861:Hydrogen Peroxide; D008853:Microscopy; D008943:Mitral Valve; D011092:Polyethylene Glycols; D012756:Sheep; D012997:Solvents; D014021:Tissue Preservation / Q000379:methods*
chemical_list: D000891:Anti-Infective Agents, Local; D000894:Anti-Inflammatory Agents, Non-Steroidal; D005343:Fibrinolytic Agents; D005404:Fixatives; D012997:Solvents; D011092:Polyethylene Glycols; D005169:Factor VIII; D003094:Collagen; D006861:Hydrogen Peroxide; D005976:Glutaral