1 Department of Cardiovascular Surgery, University Hospital Frankfurt and Goethe University Frankfurt, Theodor-Stern-Kai 7, 60596 Frankfurt/Main, Germany. Electronic address: tomasholubec@email.cz.
2 Department of Cardiovascular Surgery, University Hospital Frankfurt and Goethe University Frankfurt, Theodor-Stern-Kai 7, 60596 Frankfurt/Main, Germany.