Application Of MSCT In Hepatic Vein Outflow Tract Before And After Adult Living Donor Liver Transplantation Using Right Lobe Graft

Objective To study the clinical application of multi-slice CT angiography(MSCTA) in hepatic vein anatomy and variation of donor,hepatic vein reconstruction and congestion of recipient in LDLT using right lobe graft.Methods Enhanced MSCT covering abdomen was perfomed in 89 pre-donors and 73 recipients,the delay time of portal vein phase was 60-70s,MPR,MIP and VR were aquired based on the postprocessed date with thickness of 2.5 mm and interval of 1.25 mm.The rate of forming a common trunk of LHV and MHV,the distance and angle between RHV and MHV were also explored.The frequency,diameter of IRHV and the distance from RHV were measured.The number and diameter ofⅣ,Ⅴ,Ⅷsegment tributaries were measured and types of MHV,LHV were classified.The operation road map were designed according to MSCTA evaluation and they were compared with the operation results.The reconstructive type of hepatic vein was identified,the anastomoses of V5,V8 segment tributaries of MHV and IRHV were assessed.When the bridge veins were abnormal,the hepatic vein anatomy types were compared,the changes of TB within one week after operation were analysed. The density changes of HVC with and without MHV and corresponding hepatic vein were analyzed.The flow rate of RHV,MHV and bridge vein were measured at postoperative 7 days,the security of graft with and without MHV was compared.Results The rate of forming a common trunk of LHV and MHV was 57.30%.The average distance and angle between RHV and MHV was 11.07 mm±3.35 mm and 45.76°±16.63°.There were seven types of main hepatic vein:RHV thick(n=24); MHV thick(n=4);LHV thick(n=5);RHV,LHV equal(n=17);RHV,MHV equal (n=8);MHV,LHV equal(n=7);RHV,MHV,LHV equal(n=24).When RHV was relatively thick,it was fit to right lobe graft wihout MHV.The frequency of IRHV was 55.06%,the frequency of single,double and three IRHV were 61.23%,36.73%, 2.04%respectively,they occured mostly in MHV thick type.The diameter of IRHV larger than 5 mm and distance more than 40 mm was 23.19%.IRHV larger than 5 mm should be reserved in the operation.There were 185 V8,149 V5of MHV, 23.78%V8,42.28%V5 larger 5 mm.The length of V8 and V5 were 0.00 mm-71.80 mm,43.90 mm-l 04.80 mm,V8 and V5 larger than 5mm should be reserved and reconstructed in graft without MHV.The shape of MHV included 5 types: bifurcation(n=33);branch(n=34);end-furcation(n=13);truck(n=6);branchlet (n=3).The types of LHV were classified:A1,only reflowing into MHV(n=14);B1, mainly reflowing into MHV(n=4),both type A1 and B1 were not fit to the graft without MHV;C1,only reflowing into LHV(n=20);D1,mainly reflowing into LHV (n=9),both type C1 and D1 may choose graft with MHV;type E1,reflowing into both MHV an LHV equally(n=22).There were 4 types of LHV whenⅣa segment tributaries formed a trunk.The analyses of MSCTA were consistant with the results of operation.There were no statistic significance of flow rate between RHV and RHV,bridge vein and MHV in liver graft without and with MHV.Large segment tributaries of MHV and IRHV were reconstructed.Reconstructive types and numbers were following:V5(n=2),V8(n=2),V5和V8(n=19),V5和IRHV (n=2),V5,V8和IRHV(n=10),90 veins were reconstructed in 35 cases,3 becoming thin,1 showing narrow,the course and diameter of other veins were displayed no abnormality.The tendency of TB in recipients with liver graft of normal and thin bridge veins kept in concordance.HVC in some liver graft with or without MHV were displayed high density,iso-density or low density in four phases of CT,the density changes of congestion included 7 types,few graft with MHV and in RHV relatively thick type without MHV occured congestion.Conclusion MSCTA can clearly detected course,anatomic type and variation of hepatic vein correlated with tranplantation.It is helpful to choose the proper donor and useful to definite the safe cross-section of right lobe graft.It can detect the course and distribution of reconstructed veins and identify the degree of narrow vessels.It is beneficial to discover hepatic vein congestion in earlier period and helpful to assess the liver function of recipients and provide useful information to direct clinical therapy.