1 The National Research University Project, RIHES, Chiang Mai University, Chiang Mai, Thailand Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
2 Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand Academic Division of Human Development & Health, Faculty of Medicine, University Hospital Southampton, United Kingdom Shanghai Jiao Tong University School of Medicine, Shanghai, China rm1@soton.ac.uk.