Doppler Ultrasound Evaluation of Postoperative Portal Vein Stenosis in Adult Living Donor Liver Transplantation

Aim. To evaluate the postoperative portal vein stenosis (PVS) and the diagnostic efficiency of Doppler ultrasound (DUS) in adult living donor liver transplantation (ALDLT). Materials and Method. From January 2007 to December 2008, 103 ALDLTs were performed and postoperatively followed by routine DUS. The morphologic narrowing at the anastomotic site (AS) of the PVS was analyzed. We calculated the PV stenotic ratio (SR) using the following formula: SR (%) = PRE-AS/PRE (PRE = pre-stenotic caliber). An SR >50% was defined as the critical point for PVS. We also calculated the velocity ratio (VR) between the AS and PRE, and set the significant VR as >3:1. Statistical analyses were carried out to determine clinical significance. Results. Using the definition of morphologic PVS by DUS, there were total 20 cases (19.4%) in this series with SR >50%, which included 17 cases with VR >3:1. Eight cases of severe PVS had a stenotic AS >5 mm and subsequently underwent interventional management. Doppler criteria of SR and VR values were elevated up to 75.8% and 7.5:1, respectively, in these treated cases. Two cases of severe PVS subsequently developed PV thrombosis. Intervention by balloon dilation and/or stenting was performed successfully in this PVS case. Conclusion. DUS is the most convenient and efficient imaging modality to detect and follow postoperative PVS in ALDLT. The Doppler criteria of SR and VR are both sensitive but less specific. Cases of AS <5 mm require interventional management for good long-term graft survival.