Risk factors and outcomes in post-liver transplantation bile duct stones and casts: A case-control study

Bile duct stones and casts (BDS) after liver transplantation are associated with significant morbidity. Risk factors for BDS formation and the efficacy of treatment in liver transplant recipients have not been systematically studied. The aim of this study was to evaluate potential risk factors for the formation of BDS in patients post-liver transplant. A case-control study of consecutive liver transplant recipients at a university hospital from 1989 to 2007 was performed to identify risk factors for BDS formation. Cases included all liver transplant recipients with BDS, excluding those with concurrent t-tubes or biliary stents. Controls were chosen randomly from the total liver transplant population matched for year of transplantation. Pre- and post-OLT risk factors were analyzed with univariate and multivariate analyses. There were 49 cases and 101 controls over an 18-year-period (1289 liver transplants performed) with an incidence of 3.8% for BDS. In the cases, the median time to BDS diagnosis was 613 days from time of transplant. The controls had a median follow-up of 1530 days. Use of ursodeoxycholic acid was protective (P = 0.005), whereas bile duct pathology (P = 0.003), total cholesterol >/= 200 mg/dL (P = 0.008), and triglyceride >/= 150 mg/dL (P = 0.008) were significant risk factors for BDS formation. Endoscopic retrograde cholangiopancreatography (ERCP) was technically successful in all cases with resolution or improvement of liver chemistries in 59% (29) of patients. In conclusion, significant risk factors for forming BDS included bile duct pathology and elevated total cholesterol and triglyceride levels. Ursodeoxycholic acid had a significant effect in preventing the development of posttransplant BDS and should be used in those that are at increased risk. ERCP is a safe and effective diagnostic and therapeutic modality for these patients.