AIM: To study the postoperative complications in patients with preoperative portal vein thrombosis (PVT)undergoing liver transplantation (LT) and to evaluate the complications with Doppler ultrasonography.METHODS: Retrospective studies were performed on 284 patients undergoing LT (286 LT) with respect to pre- and postoperative clinical data and Doppler ultrasonography. According to the presence and grade of preoperative PVT, 286 LTs were divided into three groups: complete PVT (c-PVT), partial PVT (p-PVT) and non-PVT, with 22, 30 and 234 LTs, respectively. Analyses were carried out to compare the incidence of early postoperative complications.RESULTS: PVT, inferior vena cava (IVC) thrombosis,hepatic artery thrombosis (HAT) and biliary complications were found postoperatively. All complications were detected by routine Doppler ultrasonography and diagnoses made by ultrasound were confirmed by clinical data or/and other imaging studies. Nine out of 286 LTs had postoperative PVT. The incidence of the c-PVT group was 22.7%, which was higher than that of the p-PVT group (3.3%, P ＜ 0.05) and non-PVT group (1.3%, P ＜ 0.005). No difference was found between the p-PVT and non-PVT groups (P ＞ 0.25).Of the 9 cases with postoperative PVT, recanalizations were achieved in 7 cases after anticoagulation under the guidance of ultrasound, 1 case received portal vein thrombectomy and 1 case died of acute injection. Ten LTs had postoperative IVC thrombosis. The c-PVT group had a higher incidence of IVC thrombosis than the non-PVT group (9.1% vs 2.6%, P ＜ 0.05); no significant difference was found between either the c-PVT and p-PVT groups (9.1% vs 6.7%, P ＞ 0.5) or between the p-PVT and non-PVT groups (P ＞ 0.25). Nine cases with IVC thrombosis were cured by anticoagulation under the guidance of ultrasound, and 1 case gained natural cure without any medical treatment after 2 mo. HAT was found in 2 non-PVT cases, giving a rate of 0.7%among 286 LTs. Biliary complications were seen in 12LTs. The incidence of biliary complications in the c-PVT,p-PVT and non-PVT groups was 9.1%, 3.3% and 4.3%,respectively (P ＞ 0.25 for all), among which 2 stenosis led retransplantations and others were controlled by relative therapy.CONCLUSION: C-PVT patients tend to have a higher incidence of PVT and IVC thrombosis than non-PVT patients after LT. The incidence of postoperative complications in p-PVT patients does not differ from that of non-PVT patients. A relatively low incidence of HAT was seen in our study. Doppler ultrasonography is a convenient and efficient method for detecting posttransplant complications and plays an important role in guiding treatment.