Po-Kuei Hsu1, Yu-Chung Wu2. 1. Division of Thoracic Surgery, Department of Surgery, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: hsupokuei@yahoo.com.tw. 2. Division of Thoracic Surgery, Department of Surgery, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan.