Intrahepatic venous collaterals formation following outflow block in adult-to-adult living donor liver transplantation.

A right liver graft without the middle hepatic vein (MHV) trunk is now commonly used in adult-to-adult living donor liver transplantation (LDLT), but it is unclear whether hepatic venous collaterals would develop in clinical patient just after occlusion of hepatic veins. Between January 2005 and October 2006, 56 consecutive adult patients underwent LDLT using right lobe grafts without MHV in our center. Twenty-four patients (42.9%) had MHV tributaries reconstruction. Vascular flow in the graft and interposition vein graft patency was checked by Doppler ultrasonography (US) daily during hospital stay and monthly follow-up after discharge for 2 y. Among 24 cases with MHV reconstruction, interpositional graft block occurred in one case within 7 d after transplantation. A reversed flow in MHV tributaries and collaterals between MHV and right hepatic vein (RHV) was detected by Doppler US. Vessel graft blocks were found in 10 of 22 cases of MHV tributaries reconstruction between 4 to 9 mo after transplantation. Collaterals formation between MHV and RHV developed in 4 of 10 cases of vessel graft block, and their graft function did not deteriorate. In conclusion, nearly half of the patients needed reconstruction of MHV tributaries when a right lobe graft without MHV was used in LDLT. The authors thought that the reconstruction of MHV tributaries should be established when the congested area was dominant by the clamping test or when the diameter of the tributaries was >5 mm. It was found that there may not be any problems if reconstructed vessel graft obstruction was found 3 mo after transplantation, as intrahepatic venous collaterals between MHV and RHV could develop.