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Agathos E.A.,Athens Medical Psychico Clinic | Shen M.,Perouse Medical Shanghai Co | Katsiboulas M.,Surgery Academy | Koutsoukos P.,University of Patras | Gloustianou G.,Athens Medical Psychico Clinic
ASAIO Journal | Year: 2011

Calcification remains the main reason for failure of bioprosthetic valves. The aim of this study was to evaluate the in vivo calcification response of a new bioprosthetic valve, derived from cardiac tissue of Phoca groenlandica. Aortic and pulmonary leaflets, bovine, and Phoca groenlandica pericardia were fixed in buffered glutaraldehyde solution. Tissues were divided into four groups: group 1, bovine pericardium (BP); group 2, pulmonary leaflets; group 3, seal pericardium; and group 4, aortic leaflets. All samples were implanted subdermally into four sets of eight female 12-day-old Wistar rats for 21 days. The tissues were divided into two parts for calcium measurement, and histology with hematoxylin-eosin, von Kossa, and Weigert Van Gieson staining. All groups experienced significant calcification. Group 1 with 1.39 mg/g (0.34) before and 125.78 mg/g (21.48) after implantation (p < 0.001), group 2 with 1.50 mg/g (0.43) before and 151.85 mg/g (19.1) after (p < 0.001), group 3 with 3.15 mg/g (0.62) before and 116.38 mg/g (33.74) after (p < 0.001), and group 4 with 1.84 mg/g (0.52) before and 126.95 mg/g (13.37) after (p < 0.001). Explant samples showed foreign body response, disorganized collagen, and obvious calcification. The cardiac valve and pericardium of Phoca groenlandica calcify to the same extent as the BP. Copyright © American Society of Artificial Internal Organs.

Agathos E.A.,FETCS | Agathos E.A.,Perouse Medical Shanghai Co | Agathos E.A.,National and Kapodistrian University of Athens | Shen M.,FETCS | And 14 more authors.
ASAIO Journal | Year: 2012

Biological valves offer significant advantages over mechanical valves, and for this reason, we studied the possibility of using a new animal source such as that of Phoca groenlandica. Four aortic and four pulmonary leaflets were cut radially and their uniaxial tensile testing was evaluated. Three prototype pulmonary valves of Phoca groenlandica preserved in buffered glutaraldehyde solution 0.625% at pH 7.4 were mounted on a 19, 21, and 27 mm novel support system (stent) with heart shape commissural posts covered with polytetrafluoroethylene. The valves were tested in a steady flow system, the peak pressure gradients (PPGs) were measured, and the effective orifice areas (EOAs) were calculated for the flows of 3, 4, 5, 6, and 8 L/min. There were five different measurements for each flow variant. Aortic and pulmonary leaflets present no statistically significant difference in failure strength (p = 0.93). The PPGs across the valves for the flow of 3, 4, 5, 6, and 8 L/min for all three tested valves were low and the corresponding calculated EOAs were large. The new bioprosthetic valve derived from the pulmonary valve of Phoca groenlandica mounted on this novel support system presented a satisfactory hydrodynamic performance in a steady flow system. More research is needed before it can be considered suitable for human cardiac valve replacement. Copyright © 2012 by the American Society for Artificial Internal.

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