[1] Qingdao Univ, Dept Human Anat Histol & Embryol, Sch Basic Med, Qingdao 266071, Shandong, Peoples R China
[2] Qingdao Univ, Affiliated Hosp, Dept Cardiac Surg, Qingdao 266071, Shandong, Peoples R China
[3] Third Mil Med Univ, Affiliated Xinqiao Hosp, Dept Urol, Chongqing 400038, Peoples R China
[4] Qingdao Univ, Sch Basic Med, Coll Med, Qingdao 266071, Shandong, Peoples R China