Table 1. Acceptable and unacceptable rates for the 4 CUSUMyparameters

Acceptable rate Unacceptable rate s h0, h1

Procedural success 85% 70% 0.219 �2.476Adequate biopsy 70% 50% 0.397 �2.593Accuracy of appearance 85% 70% 0.219 �2.476Complications 5% 10% 0.072 �2.941

yde Oliveira Filho GR, Anesth Analg 2002;95:411-6; h1 Z Upper control limit; h0 Z lower control limit.

Abstracts

Comparison of Cases of Resolved versus Persistent Bile Leaks at Follow-upERCP

Su1643Assessment of Balloon-Assisted Cholangioscopy Learning CurveWith Respect To Parameters of Procedural Competence and SafetyVipul Aggarwal*1, Peter Lim1, Patrick H. LAM2, Philip I. Craig11Department of Gastroenterology and Hepatology, St George Hospital,Sydney, NSW, Australia; 2The Orthopaedic Research Institute, St GeorgeHospital Campus, Sydney, NSW, AustraliaBackground: Balloon-assisted cholangioscopy (BAC) using slim scopes has improvedimage quality and lower costs compared to SpyGlass and mother-baby systems. EarlyBAC studies were in Asian patients with bile ducts over 8mm, however, we achievedsimilar results in predominantly non-Asians with smaller ducts (GIE 2013:77 (suppl):AB125). Despite emerging data on the utility of BAC as a safe diagnostic procedurewith high success rates, there appears to be a resistance to take up the technique.Plausibly this could be due to limited data concerning BAC learning curves. Aims: Toprospectively assess the learning curve of an experienced biliary endoscopist startingBAC with respect to parameters of procedural competence and safety including: 1)acceptable success and complication rates 2) adequate biliary biopsies 3) accurateinterpretation of BAC images and; 4) changes in BAC procedural time. Methods: 4.9-5.5mm (Olympus N180, XP190) scopes used. Parameters assessed were, proceduralsuccess: scope passage to the hilum or pathology; adequate biopsy: histologicalsample adequate for diagnosis; accuracy of appearance: cholangioscopic visualdiagnosis compared with final diagnosis from histology and clinical follow up, and;complications. Learning curves were constructed using a Cumulative Sum (CUSUM)method* for procedural and biopsy success, to determine the number of proce-dures required to attain a predetermined success rate. Table 1 lists acceptable andunacceptable rates for each parameter. Results: 90 BAC procedures were performed(74pts) betweenDec2009 and July 2013. BACwas successful in 69of 74pts and indicationsincluded assessment of indeterminate biliary strictures and lesions (52), assessment ofampullary adenomas (9) and stone therapy (8). Procedural success: 93% (84/90) (Fig 1).Thenegative directionof theCUSUMplot impliesprocedural competence from theoutset.The lower limit (85% success) was crossed at 40th procedure. Median bile duct diameterwas 7 (2-20) mm with no correlation between diameter and procedural success. The me-dian procedural time was 28.5 (12-90) min however, BAC procedural time decreased withexperience (rZ-0.306, p!0.03, Spearman’s correlation). Adequate biopsies were obtainedin 78%(35/45) procedures. CUSUMsuggested acceptable biopsy rates from theoutsetwitha 70% rate after 10 procedures. BAC appearance correctly identified 94% (49/52)malignantand benign biliary lesions. Acceptable accuracy for BAC appearance was achieved from theoutset with an 85% rate reached at 31 procedures by CUSUM. Complications, generally

AB244 GASTROINTESTINAL ENDOSCOPY Volume 79, No. 5S : 2014

mild, occurred in 8% (7/90) procedures. Conclusions: In BAC patients with smaller bileducts: 1) Learning curves showed early acceptable procedural success and complication

rates; 2) Procedural time decreased with experience; 3) The study supports the adoptionof BAC by experienced biliary units.

Figure 1. CUSUM for procedural success in 90 cholangioscopy proce-dures. h1 Z upper control limit (70% unacceptable rate); h0 Z lowercontrol limit (85% acceptable rate). The lower limit line crossed at the40th procedure.

Su1644Implication of Liver Test Fluctuations Prior to ERCP for Bile DuctStonesJames L. Buxbaum*, Sajiv Chandradas, Bhavesh Patel, Niraj Jani,Didi MwengelaDivision of Gastrointestinal & Liver Diseases, Univ. of SouthernCalifornia, Los Angeles, CAIntroduction: ERCP is the primary method of bile duct stone removal. Given proceduralmorbidity, it is reserved for those with intermediate to high probability of choledocholi-thiasis. It has been suggested that even in patients whomeet these criterion ERCPmay bereconsidered in those in whom liver tests decline during the time between presentationand the planned procedure. Inflection (fall-then-rise or rise-then-fall) and increase in livertests have been proposed to represent persistent intraductal stones. Our aim is to assesswhether liver test fluctuations in the period immediately prior to ERCP predicts the pres-ence or absence of bile duct stones. Methods: We analyzed consecutive patients whounderwent ERCP for intermediate or high probability of choledocholithiasis. Three setsof liver tests (AST, ALT, alkaline phosphatase, and total bilirubin) immediately prior to theprocedure were recorded as well as noninvasive imaging results, clinical presentation,and demographics. The primary outcome was the confirmation of bile duct stones versusnormal duct by cholangiography. Patients with cholangitis and strictures were excludedfrom the analysis. Results: Between September 2010 and November 2012, ERCP wasperformed in 390 patients among whom 305 had definite stones and 85 normal ducts.The median age was 40, 85% were of Hispanic ethnicity, and 71% were female. Non-invasive imaging prior to ERCP was performed in 98%. All of the patients with bile ductstones and those confirmed to have normal bile ducts initially presented with elevatedAST, ALT, and total bilirubin (Table 1). Alkaline phosphatase elevated three time theupper limit of normal (3xULN) was more frequent in those with stones (p!0.1). Thesensitivities of the inflection, decrease, or increase of AST, ALT, alkaline phosphatase, andtotal bilirubin for bile duct stones were all!0.6 (Table 1). However, increasing alkalinephosphatase, AST, and ALT had a specificity of O0.8. Conclusions: In patients with in-termediate to high risk of bile duct stones increase, decrease, or inflection of AST, ALT,alkaline phosphatase, or total bilirubin immediately prior to the procedure are not sen-sitive indicators of the presence or absence of stones. ERCP should not be routinelyreconsidered based on fluctuation of these tests. If another high fidelity method for bileduct stone confirmation, particularly endoscopic ultrasound, is available immediatelyprior to ERCP, it would be most likely to change management in patients who do not

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Table 1Stone (%) Normal Bile Duct (%) Sensitivity Specificity

Alkaline Phosphatase Inflection 42.4 38.9 0.42 0.54

Decreasing Alkaline Phosphatase 41.9 50.0 0.42 0.49

Increasing Alkaline Phosphatase 26.1 25.0 0.26 0.85

AST Inflection 38.6 58.8 0.39 0.78

Decreasing AST 53.7 57.1 0.54 0.32

Increasing AST 18.6 7.1 0.19 0.83

ALT Inflection 38.3 33.3 0.38 0.63

Decreasing ALT 56.4 60.7 0.56 0.43

Increasing ALT 18.8 17.9 0.19 0.84

Bilirubin Inflection 38.2 11.8 0.38 0.49

Decreasing Bilirubin 39.8 39.3 0.40 0.57

Increasing Bilirubin 24.7 39.3 0.25 0.77

Age O 55 20.0 30.6 0.22 0.69

Filling Defect on Imaging 71.1 53.1 0.71 0.47

Alkaline Phosphatase O100 U/L (1XULN) 87.1 86.6 0.87 0.13

Alkaline PhosphataseO300 U/L (3xULN) 21.7 11.9 0.22 0.88

ASTO40 U/L (1XULN) 100.0 100.0 1.00 0.00

ASTO120U/L (3XULN) 58.8 56.1 0.59 0.44

ALTO40 U/L(1xULN) 100.0 100.0 1.00 0.00

ALTO120 U/L (3xULN) 72.8 73.1 0.73 0.27

BilirubinO1 mg/dL (1xULN) 100.0 100.0 1.00 0.00

BilirubinO3 mg/dL (3xULN) 41.7 37.3 0.42 0.63

Table 1. Predictors of a normal postoperative cholangiogram

Normal post-op

Cholangiogram

(n[ 41)

Abnormal

Cholangiogram

(n[89)

P

value

Female Gender 75.6% (31) 66.3% (59) 0.29

Age [mean� Standard error of mean

(SEM)]

49.8�2.8 years 52�2.2 years 0.31

Cholecystectomy at Tertiary Center 70.7% (29) 68.5% (61) 0.6

Indication for Surgery

Acute cholecystitis 36.6% (15) 35.9% (32) 0.18

Biliary Colic 39% (16) 51.7% (46)

Biliary Pancreatitis 24.4% (10) 12.4% (11)

IOC finings

Filling defect 80.5% (33) 93.3% (83) 0.085

Non-passage of Contrast 14.6% (6) 5.6% (5)

Stricture 4.9% (2) 1.1% (1)

ERCP finding

Periampullary Diverticulum 7.3% (3) 7.8% (7) 0.91

Duct Diameter (mean� SEM) 8.5�0.3 mm 8.7�0.4 mm 0.7

Time to ERCP (median� interquartile

range)

2.5 (1.5-6.4) days 2.6 (1.6-5.4) days 0.3

Abnormal Liver Enzymes pre-ERCP 65.9% (27) 68.5% (61) 0.76

Abstracts

have elevated alkaline phosphatase and in those who do not have increasing AST, ALT, oralkaline phophatase.

.

Su1645Evaluation of Patients With Suspected Bile Duct Stone onIntraoperative Cholangiogram (IOC): Should EndoscopicRetrograde Cholangiopancreatography (ERCP) Be the Initial Studyof Choice?Jason Bill*, Daniel Mullady, Faris Murad, Riad R. Azar, Jeffrey J. Easler,Dayna S. Early, Steven a. Edmundowicz, Vladimir M. KushnirGastroenterology, Washington University School of Medicine, St. Louis, MOBackground: ERCP is currently the method of choice for the postoperative evalua-tion of suspected bile duct stones seen on IOC. The false positive rate of IOC hasranged widely in prior studies, from 2-60% and it is unclear whether there arespecific predictors that could be used risk stratify patients to undergo postoperativeERCP vs. less invasive diagnostic testing. Aims: 1. Evaluate the sensitivity of IOC foridentifying common bile duct stones (CBDS). 2. To identify those patients withabnormal IOC who are most likely benefit from a postoperative ERCP to evaluate forCBDS. Methods: A retrospective study of 130 (age 51.3�1.7 years, 69.2% female)consecutive patients who underwent ERCP for the evaluation of abnormalitiesidentified on IOC at a single center between 2005-2013. Univariate and multivariateregression analyses were performed to determine predictors of CBDS on postop-erative ERCP. Predictors included gender, bile duct diameter, age, BMI, time toERCP, abnormal liver function tests, location of IOC (community vs. academichospital), indication for cholecystectomy and findings on IOC. ERCP proceduraldetails and complications were recorded. Results: IOC findings included: filling defectin the bile duct 116 (89.2%), non-passage of contrast into duodenum 11 (8.5%) and distalbile duct stricture 3 (2.3%). ERCP was successful in all 130 subjects. Median(interquartilerange) time from cholecystectomy to ERCP was 2.5 (1.5-5.8) days. Biliary cannulation wasconsidered difficult in 8 (6.2%) cases, pancreatic duct stent was placed in 14 (10.8%) casesand pre-cut sphincterotomy was required to obtain biliary access in 4 (3.1%) cases. 41(31.5%) had subjects had a normal cholangiogram at time of ERCP. Of those that wereabnormalCBDSwere found in87(66.9%),malignantbiliary stricture in1(0.8%)andbile leakin1(0.8%).PresenceofCBDSat timeofERCPwasnot significantly associatedwithanyof theincluded variables, on univariate (table 1) or multivariate analysis. ERCP related complica-tions occurred in 6 (4.3%)patients, including self-limitedpost-sphincterotomybleeding in 3(2.3%) and mild post-ERCP pancreatitis in 3 (2.3%). Conclusions: In this study 31.5% ofpatients with a suspected bile duct stone on IOC had a normal postoperative ERCP.Presence of CBDS on post-operative ERCP could not be predicted based on the includedvariables. If less invasive diagnostic modalities had been used to screen patients prior toERCP significant pathology could have been missed in 1/130 patients (bile leak). Ourresults indicate that use of less invasive diagnostic modalities, such as endoscopic ultra-sound or MRCP may be a reasonable alternative to up front ERCP in patients with sus-pected CBDS on IOC.

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Su1646Diagnostic Yield of Magnetic ResonanceCholangiopancreatography (MRCP) in Patients With IntermediateProbability of CholedocholithiasisHari P. Sayana*1, Mir Fahad Faisal1, Dany Jacob1, Stephen Simon2,Sreenivasa Jonnalagadda11Gastroenterology and Hepatology, University of Missouri - Kansas City,Kansas City, MO; 2Department of Biomedical and Health informatics,University of Missouri- Kansas City, Kansas City, MOBackground: Patientswith suspectedcholedocholithiasis canberisk stratified intoa low(!10%), intermediate (10-50%) or high probability (O50%) of having common bile duct(CBD) stonebasedon clinical predictors. Presenceof anyof the following; bilirubinO4mg/dl, CBDstoneon trans-abdominal ultrasound (US), ascending cholangitis or dilatedCBDonUS (O6 mmwith gall bladder in situ) along with a bilirubin level 1.8-4 mg/dl is consideredhigh probability and preoperative ERCP is recommend. Presence of abnormal liver chem-istries other than bilirubin, ageO55 years, or gall stone pancreatitis is considered inter-mediate probability and pre-operative Endoscopic ultrasound (EUS), Magnetic ResonanceCholangiopancreatography (MRCP) or Intra-operative cholangiography (IOC) is recom-mended. In patients with intermediate probability, ERCP is deferred due to its potential riskof complications. MRCP is commonly performed, as EUS is not widely available. However,the diagnostic yield of MRCP in this subset of patients is not well defined. Methods: Aretrospective review of all patients admitted with symptomatic cholelithiasis that hadcholecystectomy and underwent MRCP for evaluation of choledocholithiasis between theperiods of Jan 2007 and Oct 2013 at an academic tertiary referral center was performed.Patients who met the criteria for intermediate likelihood of CBD stone and underwentperioperative MRCP, IOC or ERCP were included in the study. Patients with any intrinsicliver disease, or hepato-biliary malignancy or! 18 years of age were excluded. Pertinentdemographic, clinical, biochemical and ultrasound parameters were collected. Results: Atotal of 215 patients met the inclusion criteria for intermediate probability of choledo-cholithiasis. Of these, 124 patients got either IOC or perioperative ERCP and wereincluded in final analysis. Mean age of all patients was 52�20 years with 35 % males(nZ43). A total of 81 patients had IOC and 51 had ERCP. MRCP was positive for CBDstone in 28% of patients (nZ35/124). CBD stone was present in 31% (nZ39/124) pa-tients as confirmed by either IOC (nZ7/81) or ERCP (nZ35/51). False positive rate ofMRCP was 31.4% (11/35) and false negative rate was 17% (nZ15/89). Of the 15 falsenegative patients, 5 had IOC that showed stone and 10 had pre-op ERCP based onpersistently elevated liver enzymes and were found to have impacted stone. Sensitivityand specificity of MRCP in detection of impacted stone was 61% and 87% respectively.Positive predictive and negative predictive values were 68% and 83% respectively.Conclusion: MRCP has a poor sensitivity in patients with intermediate probability of chol-edocholithiasis. Intraoperative cholangiography or endoscopic ultrasound is recommen-ded when available for definitive evaluation for a residual bile duct stone in this subgroup

Su1647Hmb Score Differentiates Prognosis of Patients With MalignantBiliary Stricture Receiving Only Conservative Therapy After ERCPRui Huang, Hui Luo, Yanglin PAN*, Xuegang GuoDepartment of Gastroenterology, Xijing Hospital, Xi’an, ChinaBackground: ERCP is widely used for the palliative treatment of malignant biliarystricture (MBS). After biliary drainage, some patients with MBS may choose con-servative treatment only because of several reasons. The survival data and the high-risk factors related to survival in this group of patients are largely known. Patientsand Methods: In this retrospective study, 157 consecutive patients with definiteMBS underwent biliary drainage by ERCP in Xijing Hospital were enrolled be-tween Jan 2011 and July 2013. All the patients received only conservativetherapy after ERCP. The effect of patient- and MBS-related parameters onoverall survival (OS) was investigated by log rank test. A point score to

ume 79, No. 5S : 2014 GASTROINTESTINAL ENDOSCOPY AB245