ABSTRACT
BACKGROUND AND AIMS OF THE STUDY: Structural valve deterioration of bioprostheses is mainly caused by progressive calcification. It has not yet been convincingly demonstrated whether pericardial or porcine bioprostheses are more prone to calcification. METHODS: A previously described in vitro test protocol consisting of non-destructive holographic interferometry, which permits quantitative deformation analysis of heart valves and accelerated dynamic calcification in vitro was used to evaluate five stented pericardial bioprostheses of different sizes and design (three or two leaflets) from one manufacturer. The extent of calcification was assessed after up to 20 x 10(6) cycles in the valve tester by microradiography, and areas of calcification were compared by holographic interferometry using computerized image processing. Calcification was confirmed by EDX-analysis and Von Kossa staining. Results were compared with in vitro testing of 25 porcine bioprostheses from different manufacturers. RESULTS: The tested pericardial bioprostheses had an individual distribution of mechanical stresses detectable by holographic interferometry, which resulted in different calcification of valve leaflets. A strong correlation between calcification and stress distribution was found (correspondence of affected areas: 82.3 +/- 10.1%, r = 0.97). Variability in calcification and stress distribution, respectively, of pericardial valves compared well with our findings for porcine prostheses. Overall, the extent of leaflet calcification was not statistically different for pericardial and porcine bioprostheses (p = 0.21). CONCLUSIONS: The biological material of bioprostheses (pericardial versus porcine) does not seem to be the crucial factor in the calcification process. Mechanical stresses detectable by holographic interferometry have a more pronounced impact and predict calcification of individual prostheses, at least in the in vitro setting.
Subject(s)
Bioprosthesis , Calcinosis/pathology , Heart Valve Prosthesis , Pericardium/pathology , Animals , Cattle , Holography , Interferometry/methods , Prosthesis Design , SwineABSTRACT
Implantable left-ventricular assist devices have been remarkably free of mechanical failures. We describe an uncommon Novacor N100 PCq LVAS malfunction caused by an internal short circuit of the device due to urine aspiration via the vent line. Device replacement was managed via a subcostal approach without sternotomy. Patient recovery was uneventful and successful transplantation was performed one month after the device exchange.
Subject(s)
Equipment Failure , Heart-Assist Devices/adverse effects , Prosthesis Implantation/methods , Shock, Cardiogenic/therapy , Adult , Cardiomyopathy, Dilated/complications , Cardiomyopathy, Dilated/therapy , Equipment Safety , Follow-Up Studies , Humans , Male , Reoperation , Shock, Cardiogenic/etiology , Sternum/surgeryABSTRACT
Medical data monitoring is an effective tool to insure high quality and efficient performance of health care providers. In the Department of Thoracic and Cardiovascular Surgery of the University of Muenster this is based on a comprehensive data management system. This system has been custom tailored to enable optimal monitoring of quality, performance and cost aspects based on access to all available data. Data acquisition is achieved online and allows for continuous data analysis. This data monitoring is the basis for objective quality control of medical performance as well as for the evaluation of the impact of politically induced economic restrictions on the quality of care.
