The use of PTFE graft for various hepatobiliary surgical procedures including LDLT has been permissible in the investigators' institution. Only after parenchymal transection of the donor liver, the size and shape of suitable vessel allograft for MHV reconstruction is determined. Thus the use of PTFE graft will be decided at this time after checking the list of all available allograft stored at the institutional tissue bank. The indication of PTFE use will be confined to the occasions that adequate allograft was not available. Permission for potential use of PTFE graft will be obtained from all cases of LDLT using a right lobe graft. This study protocol is approved by the institutional review board for clinical study.