2949 Diagnostic Comparison of Magnetic Resonance and Endoscopic Retrograde Cholangiopancreatography in Post-Orthotopic Liver Transplant Patients

Abstract

INTRODUCTION: In post-liver transplant patients, biliary tract complications are one of the leading causes of morbidity, graft loss and mortality. Many patients with a cholestatic pattern of liver injury or findings of dilated ducts on imaging undergo magnetic resonance cholangiopancreatography (MRCP) as the initial test prior to definitive therapy. The gold standard for diagnosis and treatment is endoscopic retrograde cholangiopancreatography (ERCP). Currently, there are limited studies on the sensitivity and specificity of MRCP at diagnosing biliary complications. Our aim is to assess whether MRCP may prevent unnecessary invasive procedures or aid in the diagnosis of biliary complications. METHODS: This is a retrospective review of patients aged ≥18 years old who underwent a liver transplant at our tertiary level transplant center from January 2007 to December 2017. Of those post-transplant patients, individuals that had both an MRCP and ERCP performed for the same indication were selected. Reports were analyzed to assess for correlation between MRCP and ERCP findings. Other factors analyzed were age, sex, race, cause of prior end-stage liver disease, and liver enzyme levels. RESULTS: A total of 30 patients were included in this study. The mean age of patients was 56 years old with 73% being male. The most common indication for MRCP was abnormal liver function tests (LFTs), followed by transplant rejection (10%), fever (6.7%), abnormal imaging (3.3%), and abnormal biopsy findings (3.3%). Of these patients, 56.7% of MRCP findings correlated with ERCP findings. When divided among indication for MRCP, prior abnormal imaging (i.e., ultrasound or CT) was associated with the highest correlation (80%) between MRCP and ERCP. When an MRCP was performed due to abnormal LFTs, only 57.9% of cases correlated with ERCP findings. The sensitivity and specificity of MRCP in diagnosing biliary pathologies was 59% and 33%, respectively. In most cases, MRCP did not correlate with ERCP findings when it failed to detect an anastomotic stricture that was seen on ERCP. CONCLUSION: MRCP findings more closely correlated with ERCP findings when performed for abnormal prior imaging rather than for abnormal LFTs. Further studies are warranted to determine if MRCPs aid in the diagnosis of biliary disorders or delay time to definitive therapy via ERCP, as these findings suggest that cases of anastomotic strictures may go undiagnosed given the low sensitivity and specificity of MRCP.