1. Department of Cardiovascular Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
2. Department of Cardiovascular Surgery, The First People's Hospital of Foshan (Affiliated Foshan Hospital of Sun Yat-sen University), Foshan, Guangdong 528000, P.R. China
3. Department of Cardiovascular Surgery, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi 541001, P.R. China