Effectiveness of cholangioscopy guided biopsy versus ERCP guided brushings in diagnosing malignant biliary strictures

Background: Evaluation of lesions of the biliary tract are essential to diagnose given the dismal outcomes of cholangiocarcinoma. Historically, these diagnoses were made using brush biopsies obtained under Endoscopic Retrograde Cholangiopancreatography (ERCP). To increase the accuracy of biliary biopsies, SpyGlassTM Discover cholangioscopy guided biopsy has been developed, providing greater tissue yield and direct visualization of the biliary epithelium. We evaluated the diagnostic accuracy of ERCP guided brushings and SpyGlassTM Discover guided biopsies at a single institution.

Methods: Following IRB approval, all diagnostic biliary biopsies utilizing both ERCP guided brushings and/or SpyGlassTM Discover between 8/2015 and 6/2022 were retrospectively evaluated. Demographic and clinicopathologic data were collected. Fischer's t-tests and Chi-square analyses were completed as appropriate (p < 0.05).

Results: Overall, 46 patients with an average age of 61 years were included in this study; 59% of the patients were female and 41% were male. 87% of patients had at least one SpyGlassTM Discover guided biopsy and one ERCP guided brushing and 13% of patients had at least one SpyGlassTM Discover guided biopsy alone. SpyGlassTM Discover correctly identified 82% of malignancies while brushings identified only 47% of malignancies.

Conclusions: SpyGlassTM Discover guided biopsies yield a greater diagnostic result than ERCP guided brushings. Therefore, SpyGlassTM Discover should be considered as the standard for diagnosing biliary lesions at our institution in conjunction with ERCP procedure. The classification of visual characteristics of biliary lesions should be investigated in the future as the high-resolution image generated by SpyGlassTM Discover can allow for detailed visual observation of strictures and potentially aid in better characterization and location of disease.