Three-dimensional contrast-enhanced MR angiography in diagnosis of portal vein involvement by hepatic tumors

AIM: To assess the accuracy of three-dimensional contrastenhanced magnetic resonance angiography (3D CE MRA) in evaluation of the portal vein involvement in patients with hepatic tumors.METHODS: 3D CE MlRA was performed in 62 patients with hepatic tumors to assess the patency of the main, right and left portal veins before hepatic surgery. A total of 186 veins were examined for encasement, occlusion and tumor thrombosis. The results of 3D CE NRA diagnosis were then correlated with the surgical-pathological and intra-operative sonographic findings.RESULTS: 3D CE MRA correctly detected 48 of 49 involved and 135 of 137 noninvolved portal veins with the sensitivity of 98 %, specificity of 99 %, positive predictive value of 96 % and negative predictive value of 99 %.CONCLUSION: 3D CE NRA is accurate in evaluation of the portal vein involvement in patients with hepatic tumors.

Portal vein embolization before major hepatectomy

To discuss the rationale, techniques and the unsolved issues regarding preoperative portal vein embolization (PVE) before major hepatectomy. After a systematic search of Pubmed, we reviewed and retrieved literature related to PVE. Preoperative PVE is an approach that is gaining increasing acceptance in the preoperative treatment of selected patients prior to major hepatic resection. Induction of selective hypertrophy of the nondiseased portion of the liver with PVE in patients with either primary or secondary hepatobiliary, malignancy with small estimated future liver remnants (FLR) may result in fewer complications and shorter hospital stays following resection. Additionally, PVE performed in patients initially considered unsuitable for resection due to lack of sufficient remaining normal parenchyma may add to the pool of candidates for surgical treatment. The results suggest that PVE is recomm-endable in treating the cirrhotic patients before major liver resection.

Portal venous arterialization resulting in increased portal inflow and portal vein wall thickness in rats

AIM： To explore the influence of portal vein hemodynamic changes after portal venous arterialization （PVA） on peribiliary vascular plexus （PVP） morphological structure and hepatic pathology, and to establish a theoretical basis for the clinical application of PVA. METHODS： Sprague-Dawley rats were randomly divided into control and PVA groups. After PVA, hemodynamic changes of the portal vein and morphological structure of hepatohilar PVP were observed using Doppler ultrasound, liver function tests, ink perfusion transparency management and three-dimensional reconstruction of computer microvisualization, and pathological examination was performed on tissue from the bile duct wall and the liver. RESULTS： After PVA, the cross-sectional area and blood flow of the portal vein were increased, and the increase became more significant over time, in a certain range. If the measure to limit the flow in PVA was not adopted, the high blood flow would lead to dilatation of intrahepatic portal vein and its branches, increase in collagen and fiber degeneration in tunica intima. Except glutamic pyruvic transaminase （GPT）, other liver function tests were normal. CONCLUSION： Blood with a certain flow and oxygen content is important for filling the PVP and meeting the oxygen requirement of the bile duct wall. After PVA, It is the anatomic basis to maintain normal morphology of hepatohilar bile duct wall that the blood with high oxygen content and high flow in arterialized portal vein may fill PVP by collateral vessel reflux. A adequate measure to limit blood flow is necessary in PVA.