Is MRCP equivalent to ERCP for diagnosing biliary obstruction in orthotopic liver transplant recipients? A meta-analysis

Background: Biliary complications are the second leading cause of morbidity and mortality in orthotopic liver transplant (OLT) recipients. Endoscopic retrograde cholangiography (ERC) is considered the diagnostic criterion standard for post-orthotopic liver transplantation biliary obstruction, but incurs significant risks. Objective: To determine the diagnostic accuracy of MRCP for biliary obstruction in OLT patients. Design: A systematic literature search identified studies primarily examining the utility of MRCP in detecting post-orthotopic liver transplantation biliary obstruction. A meta-analysis was then performed according to the Quality of Reporting Meta-Analyses statement. Setting: Meta-analysis of 9 studies originally performed at major transplantation centers. Patients: A total of 382 OLT patients with clinical suspicion of biliary obstruction. Interventions: MRCP and ERCP or clinical follow-up. Main Outcome Measurements: Sensitivity and specificity of MRCP for diagnosis of biliary obstruction. Results: The composite sensitivity and specificity were 0.96 (95% CI, 0.92-0.98) and 0.94 (95% CI, 0.90-0.97), respectively. The positive and negative likelihood ratios were 17 (95% CI, 9.4-29.6) and 0.04 (95% CI, 0.02-0.08), respectively. Limitations: All but 1 included study had significant design flaws that may have falsely increased the reported diagnostic accuracy. Conclusions: The high sensitivity and specificity demonstrated in this meta-analysis suggest that MRCP is a promising test for diagnosing biliary obstruction in patients who have undergone liver transplantation. However, given the significant design flaws in most of the component studies, additional high-quality data are necessary before unequivocally recommending MRCP in this setting.