Background: Use of the middle hepatic vein (MHV) during transplantation of the right lobe of the liver remains controversial.  The MHV may be included in right lobe liver graft to optimize hepatic venous outflow. Splanchnic hemodynamics after LDLT still poorly understood.
Aim: The aim of this study was to systematically evaluate the role MHV on hepatic hemodynamic changes.
Materials and Methods: 75 patients undergoing right lobe LDLT between January 2003 and December 2016. We compared hemodynamic changes after right lobe LDLT with MHV (group 1; n = 37) or without MHV (group 2; n = 38). The patients age ranged from 15 to 50 years old and the male-to-female ratio was 41:34. The two groups were compared in portal venous flow volume (Qpv), peak systolic velocity (PSV) and resistance index (RI) on postoperative days (PODs) 1, 3, 5, 7, 30 using colored doppler ultrasonography.
Results: Group I had higher values of Qpv  - 687±220 ml/min ;1251±491 ml/min; 1324±372 ml/min; 1231±284 ml/min; 1042±211ml/min; 1131±301 ml/min compared with group II - 647 ± 230 ml/min; 1128±385 ml/min; 1132±372 ml/min; 1019±263 ml/min; 967±254ml/min; 935±293 ml/min on PODs  0, 1, 3, 5, 7, 30 respectively. Qpv increased after graft implantation, it was higher in group I - by 564 ml/min  on POD 1 (compared to preoperative measure on POD 0); however, in group II this parameter increased by  481 ml/min. PSV and RI on POD1 increased much more in group II (from 0,53m/s to 0,66m/s and from 0,63 to 0,72 respectively) compared with group II (from 0,57m/s to 0,58m/s and from 0,62 to 0,66 respectively).
Conclusion: After right lobe LDLT with MHV, there is an increase of Qpv and total hepatic blood flow with a decrease of PSV, as a result of optimization of the venous outflow from the graft compared with blood flow of the right lobe graft without  MHV.