In Vitro and In Vivo Evaluation of Lyophilized Bioprosthetic Valve

Autor(es)

Maizato, Marina J. S. ^[1] ; Hayashida, Sergio A. ^[1] ; Taniguchi, Fabio P. ^[1] ; Higa, Olga Z. ^[2] ; Pitombo, Ronaldo N. M. ^[3] ; Cestari, Idagene A. ^[1] ; Leirner, Adolfo A. ^[1] ; Stolf, Noedir A. G. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Med, Heart Inst InCor, Bioengn Div, BR-05403000 Sao Paulo - Brazil

^[2] IPEN CNEN SP, Ctr Biotechnol, Energy & Nucl Res Inst, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Sch Pharmaceut Sci, Dept Biochem & Pharmaceut Technol, BR-05403000 Sao Paulo - Brazil

^[4] Univ Sao Paulo, Sch Med, Heart Inst InCor, Div Cardiothorac Surg, BR-05403000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ARTIFICIAL ORGANS; v. 35, n. 5, p. 490-496, MAY 2011.
• Citações Web of Science: 4

Resumo

Freeze-drying of biological tissues allows for dry storage and gamma ray sterilization, which may improve their use as a medical prosthesis. The objective of this study was to evaluate the rehydration characteristics and hydrodynamic performance of prosthetic valves before and after lyophilization. Two size 23 bovine pericardium aortic valve prostheses from different manufacturers were evaluated in a Shelhigh (Union, NJ, USA) pulse duplicator (80 ppm, 5 L/min) before and after lyophilization. Flow and transvalvular pressure gradient were registered in vitro and in vivo, and images of opening and closing of the prosthesis were obtained in the pulse duplicator in a digital camera. Rehydration was evaluated by comparison of dry valve weight with valve weight after 15 min, and 1, 24, 48, and 72 h in saline solution, inside the pulse duplicator. In vivo performance was assessed by surgical implantation in Santa Ines young male sheep in the pulmonary position after 30 min rehydration with 0.9% saline. Transvalvular pressure gradient and flow measurements were obtained immediately after implantation and 3 months after surgery when valves were explanted. Captured images showed a change in the profile opening and closing of valve prosthesis after lyophilization. The gradient measured (in vitro) in two valves was 17.08 +/- 0.57 and 18.76 +/- 0.70 mm Hg before lyophilization, and 34.24 +/- 0.59 and 30.40 +/- 0.97 mm Hg after lyophilization. Rehydration of both lyophilized valves was approximately 82%. Drying changed the profile of the opening and closing of valve prostheses, and increased on average by 83% the gradient in vitro tests. The result of the in vivo tests suggests maintaining pressure levels of the animal with the lyophilized prostheses within acceptable levels. (AU)

• Processo FAPESP: 04/09566-8 - Liofilização de tecidos biológicos: pesquisa sob ponto de vista do desenvolvimento de biomateriais
• Beneficiário: Ronaldo Nogueira de Moraes Pitombo
• Modalidade de apoio: Auxílio à Pesquisa - Temático