Technical challenges of hepatic venous outflow reconstruction in right lobe adult living donor liver transplantation

A right lobe graft that is drained by the right hepatic vein (RHV) is obtai ned by transecting the liver on the right side of the middle hepatic vein ( MHV). On occasion, a small RHV that only drains a portion of the right lobe , with the predominant outflow achieved by the MHV, is encountered. If such variation is not recognized while performing right lobe liver transplantat ion and the RHV only is used for reconstruction, venous outflow obstruction with subsequent graft congestion and eventual graft failure will occur. Ad ditionally, preservation of the main MHV and its branch drainage of the lef t lobe is crucial to avoid outflow blockage to the remaining segment 4 in t he donor. We report 4 cases showing a variant type of small RHV and large M HV branch that drain not only segments 5 and 8, but also segments 6 and 7. These variations were simultaneously associated with a large-caliber inferi or RHV that also required reconstruction. The methods used to diagnose such anatomic variations and the techniques for reconstruction in the donor and recipient are described.