1 Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, Tzyou 1st Rd, Kaohsiung 80756, Taiwan.
2 Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, No. 100, Tzyou 1st Rd, Kaohsiung 80756, Taiwan. Electronic address: ytljwc@yahoo.com.tw.