[1] Univ Rostock, Dept Cardiac Surg, Heart Ctr, Schillingallee 35, D-18057 Rostock, Germany
[2] Rostock Univ Med Ctr, Inst Pathol, Rostock, Germany
[3] Univ Rostock, Dept Diagnost & Intervent Radiol, Pediat & Neuroradiol, Rostock, Germany
[4] Univ Free State, Fac Hlth Sci, Dept Cardiothorac Surg, Bloemfontein, South Africa
[5] Univ Rostock, Dept Cardiol, Heart Ctr, Rostock, Germany