Risk factors of biliary intervention by imaging after livingdonor liver transplantation

AIM:To determine the risk factors of biliary intervention using magnetic resonance cholangiopancreatography(MRCP) after living donor liver transplantation(LDLT).METHODS: We retrospectively enrolled 196 patients who underwent right lobe LDLT between 2006 and 2010 at a single liver transplantation center. Direct duct-to-duct biliary anastomosis was performed in all 196 patients. MRCP images routinely taken 1 mo after LDLT were analyzed to identify risk factors for biliary intervention during follow-up, such as retrograde cholangiopancreatography or percutaneous transhepatic biliary drainage. Two experienced radiologists evaluated the MRCP findings, including the anastomosis site angle on three-dimensional images, the length of the filling defect on maximum intensity projection, bile duct dilatation, biliary stricture, and leakage.RESULTS: Eighty-nine patients underwent biliary intervention during follow-up. The anastomosis site angle [hazard ratio(HR) = 0.48; 95% confidence interval(CI), 0.30-0.75, P < 0.001], a filling defect in the anastomosis site(HR = 2.18, 95%CI: 1.41-3.38,P = 0.001), and biliary leakage(HR = 2.52, 95%CI: 1.02-6.20, P = 0.048) on MRCP were identified in the multivariate analysis as significant risk factors for biliary intervention during follow-up. Moreover, a narrower anastomosis site angle(i.e., below the median angle of 113.3°) was associated with earlier biliary intervention(38.5 ± 4.2 mo vs 62. 1 ± 4.1 mo, P < 0.001). Kaplan-Meier analysis comparing biliary intervention-free survival according to the anastomosis site angle revealed that lower survival was associated with a narrower anastomosis site angle(36.3% vs 62.0%, P < 0.001).CONCLUSION: The biliary anastomosis site angle in MRCP after LDLT may be associated with the need for biliary intervention.