^○chikara shiiku, yoichi kikuchi, yuta kikuchi, yoshiaki atuta (Department of cardiovascular surgery, National Obihiro Hospital, Obihiro, Japan)

^○Norihiro Kondo, Masaru Kumae, Zaiqiang Yu, Ryosuke Kowatari, Yoshiaki Saito, Anan Nomura, Takashi Ogasawara, Tomonori Kawamura, Hiroyuki Itaya, Masahito Minakawa, Kazuyuki Daitoku, Yasuyuki Suzuki, Ikuo Fukuda (Hirosaki University)

^○Fuyuki Asami, Maiko Umezawa, Yuuki Takesue, Eiichi Ooba, Masatake Katsu, Yuuki Okamoto, Kazuo Yamamoto, Shinpei Yoshii (Tachikawa General Hospital, Nagaoka, Japan)

^○Kenji Mogi, Manabu Sakurai, Tomoki Sakata, Kengo Tani, Masanori Hashimoto, Yoshiharu Takahara (Division of Cardiovascular Surgery, Institute of Cardiovascular Disease, Funabashi Municipal Medical Center)

^○Yohei Onga, Shuichirou Takanashi, Tomoya Uchimuro, Atsushi Shimizu, Kousaku Nishigawa (Sakakibara Heart Institute)