[1] Hirosaki Univ, Dept Thorac & Cardiovasc Surg, Grad Sch Med, 5 Zaifu Cho, Hirosaki, Aomori 0368562, Japan
[2] Hirosaki Univ, Dept Diagnost Radiol, Grad Sch Med, Hirosaki, Aomori, Japan
[3] China Med Univ, Affiliated Hosp 4, Dept Thorac Surg, 4 Chongshan Rd, Shenyang 110032, Peoples R China
[4] Suita Tokushukai Hosp, Dept Cardiovasc Surg, Suita, Osaka 5650814, Japan
[5] Tokiwakai Hosp, Dept Internal Med, Fujisakimachi, Aomori 0381216, Japan
[6] Natl Hosp Org, Hirosaki Hosp, Dept Thorac Surg, Tominocho, Hirosaki, Aomori 0368174, Japan