What tissue helps operation of all four heart valves?
Pericardial heart valves:The pericardial heart valve was invented by Marian Ionescu, a British surgeon working at the General Infirmary in Leeds, England.[1] He created this artificial bioprosthetic heart valve as a three cusp structure made of chemically treated bovine pericardium attached on to a Dacron cloth covered Titanium frame.[2]