Usefulness of the single-operator cholangioscopy system SpyGlass in biliary disease: a single-center prospective cohort study and aggregated review

Indeterminate biliary strictures and difficult bile duct stones remain clinically arduous and challenging situations. We aimed to evaluate the utility of the single-operator cholangioscopy (SOC)-system SpyGlass in both conditions in a single-center biliopancreatic interventional unit and in perspective of available aggregated literature. Usefulness of SOC was assessed for the above-mentioned indications by means of the combination of successful procedural completion, clinical success and incidence of procedure-related adverse events in our own prospective cohort from 3/2010 to 7/2014 and all available literature till 6/2015. Our single-center cohort constituted of 84 patients undergoing SpyGlass either for indeterminate strictures (n= 45) or difficult stones (n= 39). In addition, a comprehensive literature review yielded 851 patients (from 15 series) for either stenosis (n= 646, 75.9 %) and difficult stones (n= 205, 24.1 %). In our series, overall procedural success amounted to 85.7 % (with 88.9 % for stenosis or 82.1 % for stones) compared to 90.7, 91.5 and 88.3 % in overall literature, respectively. Sensitivity, specificity and accuracy for visual diagnosisin our cohort added up to 83.3, 82.9 and 82.9 % compared to 90.8, 90.9 and 90.8 % in the pooled analysis. Respective figures for SOC-directed biopsiestotaled 85.7, 100 and 95.7 % in our cohort and 72.4, 100 and 84 % overall. Overall procedure-related complications varied between 9.4 and 21.4 %. The SOC-platform SpyGlass can be considered useful in the context of indeterminate biliary strictures and difficult-to-remove biliary stones. In both, SpyGlass-assisted intervention is associated with high procedural success and alters clinical outcome compared to conventional approaches with an acceptable safety profile.