Department;
of;
Urology,;
the;
First;
Affiliated;
Hospital,;
Medical;
School;
of;
Xi-an;
Jiaotong;
University,;
Xi-an;
710061,;
China;
Department;
of;
Anatomy,;
Medical;
School;
of;
Xi-an;
Jiaotong;
University,;
Xi-an;
710061,;
China;