Su1591 Magnetic Resonance Cholangio-Pancreatography (MRCP) Has Low Sensitivity in Diagnosing Biliary Strictures After Liver Transplantation: a Single Tertiary Care Center Experience

sedation assistants for deep sedation during ERCP without increasing the risk of adverse events of deep sedation. Su1590 Role of the Direct PerOral Cholangioscopy Using an Ultra-Slim Endoscope After Endoscopic Extraction of Choledocholithiasis for Detecting Small Bile Duct Lesions Obscure in Conventional Imagings Hyun Jong Choi*, Jong Ho Moon, Yun Nah Lee, Hee Kyung Kim, Hyeon Jeong Goong, Moon Han Choi, Tae Hoon Lee, Sang-Woo Cha, Young Deok Cho, Sang-Heum Park Digestive Disease Center and Research Institute, Department of Internal Medicine, SoonChunHyang University School of Medicine, Bucheon and Seoul, Korea (the Republic of); Department of Pathology, SoonChunHyang University School of Medicine, Bucheon, Korea (the Republic of) Background: Direct peroral cholangioscopy (POC) using an ultra-slim upper endoscope can provide high-resolutional endoscopic images of the bile duct. Therefore, direct POC may detect obscure bile duct lesions in preceding imaging modalities including computed tomography, magnetic resonance cholangiopancreatography, and endoscopic retrograde cholangiopancreatography. The aim of this study was to evaluate the usefullness of direct POC using an ultra-slim upper endoscope after endoscopic extraction of choledocholithiais. Methods: Total 207 patients have undergone direct POC to evaluate bile duct clearance after endoscopic extraction of choledocholithiasis. All included patients had dilated extrahepatic bile duct more than 10 mm and were undergone endoscopic sphincteroplasty before POC. Patients with defined bile duct lesions in preceding imaging modalities were excluded in this study. Direct POC was performed by using an ultra-slim (! 5.5 mm in outer diameter of distal end) upper endoscopes. Abnormal POC findings were evaluated by using narrow band imaging and forceps biopsy under endoscopic guidance, if possible. Results: Direct POC was successful in 199 patients (96.1%). Abnormal intraductal lesions were detected in 31 patients (15.6%) including 3 villous mucosal lesions, 2 papillary mucosal lesions, 14 polypoid mucosal lesions and 11 nonspecific inflammatory lesions. POC-guided forceps biopsy was successful in 28/31 patients (90.3%) with tissue adequacy for the histologic evaluation in 24/31 (77.4%). Final diagnosis by histopathologic evaluation of abnormal bile duct lesions were 4 cholangiocarcinomas, 2 intraductal papillary neoplasms in the bile duct with dysplasia, 1 bile duct adenoma with dysplasia, and 24 nonspecific inflammatory lesions. Residual stones were detected in 25 patients (14.5%) and extracted under direct POC (92%, 23/25). Cholangitis conservatively managed was occurred in one patient (0.5%, 1/ 207) after direct POC. No other significant direct POC-related adverse events were occurred. Conclusion: Endoscopic evaluation with direct POC using an ultra-slim upper endoscope after endoscopic extraction of choledocholithiasis can be helpful to detect small bile duct lesions including cholangiocarcinoma that were obscure or overlooking in preceding imaging modalities. Su1591 Magnetic Resonance Cholangio-Pancreatography (MRCP) Has Low Sensitivity in Diagnosing Biliary Strictures After Liver Transplantation: a Single Tertiary Care Center Experience Ali Akbar*, Satheesh P. Nair, Mohammad K. Ismail, Muhammad Bilal, Jason Vanatta, James D. Eason, Salil Parikh, Sanjaya K. Satapathy Gastroenterology and Hepatology, University of Tennesse, Germantown, TN; Transplant surgery, University of Tennessee, Memphis, TN; Radiology, Methodist University Hospital, Memphis, TN Aim: Biliary strictures are common complication after liver transplantation (LT). We aimed to determine the accuracy of MRCP in diagnosing biliary strictures (BS) in liver transplant recipients (LTRs) when compared to direct cholangiographic methods (Endoscopic retrograde cholangio pancreatography (ERCP) and/or percutaneous transhepatic cholangiography (PTC). Setting: Tertiary care medical center performing O100 LT a year. Methods: Retrospective chart review of LTRs from 7/2008 until 4/2014 was performed. Those who had MRCP performed for suspected BS followed by ERCP or PTC within 4 weeks were included. BS on ERCP/ PTC without prior MRCP and those who underwent surgery or followed clinically after an MRCP were excluded. A cholangiographic narrowing (on ERCP/PTC) that required balloon dilation and/or stent placement was considered a biliary stricture and was considered clinically significant if the intervention resulted in atleast 30% improvement of bilirubin (bili) and/or alkaline phosphatase (AP) within 2 weeks. Data collected include LT indication, biliary anastomosis type, Pre-MRCP bili and AP, anastomotic vs non anastomotic BS, Immunosuppression at the time of MRCP, time intervals between LT & MRCP as well as between MRCP & ERCP/PTC. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of MRCP in diagnosing biliary strictures (with known ERCP/PTC findings) were calculated. Results: After review of 679 LTRs a total of 32 patients (18 males 54.5%, median age 52.6 8.8 years) were included. All had an MRCP followed by either ERCP or PTC within 4 weeks. HCV related end stage liver disease was the most common indication for LT (19/32 59.4%). Median LT to MRCP time was 387 (35-2285) days. Biliary anastoAB342 GASTROINTESTINAL ENDOSCOPY Volume 81, No. 5S : 2015 mosis was duct to duct in all except one who had hepatico-jejunostomy. Pre-MRCP bili (8.7 8.3mg/dl) and AP (657 525 unit/L) were elevated. 27 patients (84.3%) were on tacrolimus, 13 (39.4%) on mycophenolate, 7 (21.2%) on rapamycin, 2 (6.1%) on everolimus and 1 (3%) on cyclosporine at the time of MRCP. MRCP showed anastomotic BS in 14 of 32 patients. ERCP and PTC subsequently revealed a total of 21 BS (ERCP 15, PTC 6; 20 anastomotic and 1 non-anastomotic). This included all 14 seen on MRCP (PPV of 100%). Remaining 7 BS (6-anastomotic and 1 non-anastomotic), diagnosed on ERCP (5) and PTC (2), were not detected on earlier MRCP (Sensitivity 66.7%-cholangiographic BS). However only 4 of those 7 were clinically significant (Sensitivity 77.8%). 11 LTRs had no BS on either modality (Specificity of MRCP 100%). NPV of MRCP was noted to be 61.1% for cholangiographic BS (77.8% for clinically significant BS). Conclusion: Despite excellent specificity, MRCP may not show all biliary strictures in liver transplant recipients and hence, we recommend further direct cholangiographic evaluation in appropriate clinical settings. Baseline characteristics and Results Total Patients 32 Sex (male/female) 18/14 Age (years, median SD) 52.6 8.8 Reason for transplantation (n, %) HCV Cirrhosis 19 (59.3%) HBV Cirrhosis 1 (3.1%) Alcoholic Cirrhosis 3 (9.3%) Non alcoholic steatohepatitis Cirrhosis 3 (9.3%) PBC 1 (3.1%) Sarcoidosis 1 (3.1%) Othersy 4 (12.5%) Immunosuppression at MRCP (n, %) Tacrolimus 27 (84.3%) Mycophenolic acid 13 (40.6%) Everolimus / Cyclosporine 2 (6.2%) / 1 (3.1%) Rapamune 7 (21.8%) Type of Biliary anastomosis duct-duct / bilio-digestive 31 / 1 Time from transplantation to MRCP, days (median SD) 387 35-2285 Time from MRCP to ERCP/PTC ! 4 weeks in all 32