1 Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore; Department of Cardiac, Thoracic and Vascular Surgery, National University Hospital, National University Health System, Singapore 119228, Singapore. Electronic address: vitaly_sorokin@nuhs.edu.sg.
2 Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore.