Materials characterization of explanted mechanical heart valves and comparison to patients' clinical data
Farè, S.; Brunella, M.F.; Bruschi, G.; Cigada, A.; Vitali, E.
International Journal of Artificial Organs 28(7): 701-710
2005
ISSN/ISBN: 0391-3988 PMID: 16049904 Document Number: 594380
In the present study, twelve explanted mechanical heart valves (MHVs) with pyrolitic carbon tilting disc and 14 bileaflet MHVs were analyzed to investigate the effects of material properties on valve performance and patients' general health conditions. Optical and scanning electron microscopy was used to investigate material imperfections, wear patterns or damages to housing and occluder components. All analyzed tilting disc valves exhibited wear effects, particularly due to abrasion and impact to both disc and housing. Wear of pyrolitic carbon disc and housing did not influence their in vivo performance. In the bileaflet MHVs, breakaway of the pyrolitic carbon coating sometimes caused malfunctioning and required surgical retrieval of the valve. In all cases, occurrence of clinical symptoms was more likely when wear effects were located in critical areas. The study supports a correlation between the properties of the MHVs material and patients' symptoms.