Correlation between 3D-MRCP and intra-operative findings in right liver donors

Abstract

A correct preoperative definition of the hepatic duct confluence anatomy of right liver living donors is a pivotal step in determining their candidacy for donation and planning the surgery. The purposes of this study are to evaluate the accuracy of three-dimensional Magnetic Resonance Cholangiography (3D MRCP) when compared with intraoperative cholangiography (IOC) in assessing biliary anatomy and to identify imaging characteristics that may help predict the yield of hepatic duct orifices in the right liver graft. Twenty consecutive right liver donors were imaged with 3D MRCP and IOC. The MRCP and IOC findings were compared, and the results confirmed against actual donor anatomy. Three-D MRCP accurately predicted the biliary anatomy in 18 of 20 cases. Specificity and positive predictive value of 3D MRCP in defining normal biliary anatomy was 100%. In 2 patients, 3D MRCP failed to indentify abnormal anatomy. The yield of more than one hepatic duct was associated with: (I) The presence of abnormal biliary anatomy, (II) The length of the main right hepatic duct, and (III) The presence of an acute angle at the confluence of right and left hepatic duct. In conclusion, 3D MRCP reliably represents normal biliary anatomy. The presence of anatomical variations decreases MRCP sensitivity and makes IOC or duct probing a necessary tool for accurately performing the transection of the right hepatic duct.

Keywords: Cholangiogram; live donors; liver transplantation; magnetic resonance cholangio-pancreaticogram (MRCP); preoperative evaluation.

Figure 1

Schematic drawing of Biliary ductal anatomy. Type 1 is typical. Type 2 involves triple confluence, the simultaneous emptying of the right anterior sectoral duct (RASD), right posterior sectoral duct (RPSD) and left hepatic duct (LHD) into the common hepatic duct (CHD). In type 3, the RPSD drains anomalously, and in type 4, the right hepatic duc (RHD) drains into the cystic duct. In type 5, an accessory duct is present, and in type 6, segments II and III drain individually into the RHD or CHD. Type 7 shows unclassified or complex variation. R = right hepatic duct; L = left hepatic duct; RA = right anterior segmental duct; RP = right posterior segmental duct; C = cystic duct; Acc = accessory duct (10)

Figure 2

Type 3B biliary anatomy diagnosed by MRC (A) in the 2 readings, and confirmed by IOC (B)

Figure 3

MRC (A) was reported as normal but on IOC (B) it was type 3 A

Figure 4

A case with narrow angle at confluence of ducts (78°) and 2 openings in the graft

Figure 5

Wide bifurcation angle (131°), but the distance between the bifurcation of CHD and the union between right anterior and posterior hepatic is too short. Two openings were found in the graft

Figure 6

Probing of the biliary system (through the cystic duct): a metal probe is seen passing through the cystic duct