Effect of single operator cholangioscopy on accuracy of bile duct cytology

Abstract

Introduction: This is the first study to evaluate the accuracy of bile duct brushings since the introduction of single operator cholangioscopy SpyGlass DS system in 2015. The primary aim of our study was to compare the accuracy of cytology brushings against biopsies obtained at endoscopic retrograde cholangiopancreatography (ERCP) and cholangioscopy. Method: A retrospective search for bile duct brushing specimens was performed and the charts reviewed. The gold standard for definitive diagnosis of malignancy was surgical tissue or compelling clinical evidence of malignancy. Definite negative diagnosis relied on lack of clinical/imaging features of malignancy on follow-up. Results: There was no significant difference in diagnostic accuracy of cytology specimens obtained at different procedures. Overall sensitivity for all methods was 59%, specificity 90% and accuracy of 82%. Notably, all four false-positive cases except for one were from patients with primary sclerosing cholangitis or primary biliary sclerosis. There was no significant difference in sensitivity or specificity between biopsies procured by the two methods. The combined biopsy sensitivity for all modalities was 44% with a specificity of 100%. There was 70% concordance between cytology and biopsy cases. The overall specificity and sensitivity of the combined cytology and biopsy result was 85% and 65.3%, respectively. Ranking of factors that predict clinical diagnosis shows cytology results to surpass other parameters including pancreatic mass, age and stenosis length. Similarly, the presence of two cell populations and three-dimensional clusters was not nearly as predictive of malignancy as single malignant cells. Conclusion: Biliary brush cytology specimens performed better than biopsies irrespective of whether they are procured during ERCP or cholangioscopy. The combination of cytology and biopsy had the best accuracy than either one alone.

The World Health Organization Reporting System for Pancreaticobiliary Cytopathology

“…The reported frequency of the "atypical" category for FNAB of pancreas ranges from 0 to 14% with an average of 5.5% [20,42]. The frequency in bile duct brushings is higher, ranging from 11 to 39.8%, which may be partially due to the challenge in recognizing reactive atypia inherent to primary sclerosing cholangitis, stents, and biliary stones [29,[43][44][45].…”

<p>Locally Advanced Pancreatic Ductal Adenocarcinoma: Challenges and Progress</p>

“…83,84 Brushing of the common bile/main pancreatic duct can also be performed during ERCP in patients requiring biliary stenting, although the sensitivity rate does not exceed 40% according to the available data. 83,[86][87][88] Positron Emission Tomography combined with CT (PET/CT) for diagnosis and staging of PDAC is poorly helpful and should be used selectively in addition to MDCT and/or MR. [82][83][84] However, it may be of help in the evaluation of response to NAT or in the follow-up of resected patients. [82][83][84] Patients receiving NAT should be reassessed with MDCT and/or MR despite morphological criteria indicating clinical response are still unclear.…”

Clinical practice guideline on the use of single-operator cholangioscopy in the diagnosis of indeterminate biliary stricture and the treatment of difficult biliary stones

“…However, in the remaining 5–15% of unsuccessful cases, difficult-to-extract biliary stones occur, and alternative therapies such as large-balloon papillary dilation, mechanical lithotripsy, extracorporeal lithotripsy, and cholangioscopy-guided intraductal laser or electrohydraulic treatment are required for its proper management [ 2 ]. Like difficult biliary stones, the diagnosis of the etiology of biliary strictures, which is crucial for the determination of the prognosis of the patients, through ERCP with biopsy and/or brushing, has a poor diagnostic sensitivity (35 to 70%), providing a real challenge for their practitioner [ 3 – 5 ].…”