Efficacy of digital single-operator cholangioscopy in the visual interpretation of indeterminate biliary strictures: a systematic review and meta-analysis

Objective Indeterminate biliary strictures remain a significant diagnostic challenge. Digital single-operator cholangioscopy (D-SOC) incorporates digital imaging which enables higher resolution for better visualization and diagnosis of biliary pathology. We aimed to conduct a systematic review and meta-analysis of available literature in an attempt to determine the efficacy of D-SOC in the visual interpretation of indeterminate biliary strictures. Material and methods Electronic searches were performed using Medline (PubMed), EMBASE, and Cochrane Library. All D-SOC studies that reported the diagnostic performance in visual interpretation of indeterminate biliary strictures and biliary malignancies were included. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 was used to evaluate the quality of the included studies. All data were extracted and pooled to construct a 2 x 2 table. The visual interpretation of D-SOC was compared to resected surgical specimens or clinical follow-up in the included patients. Pooled sensitivity, specificity, positive predictive value, negative predictive value, prevalence, positive likelihood ratio (+LR), negative likelihood ratio (-LR), and diagnostic odds ratio (OR) were calculated. The summarized receiver operating characteristic (SROC) curve corresponding with the area under the curve (AUC) was also analyzed. Results The search yielded 465 citations. Of these, only six studies with a total of 283 procedures met inclusion criteria and were included in the meta-analysis. The overall pooled sensitivity and specificity of D-SOC in the visual interpretation of biliary malignancies was 94% (95% CI 89-97) and 95% (95%CI 90-98), respectively, while +LR, -LR, diagnostic OR, and AUC were 15.20 (95%CI 5.21-44.33), 0.08 (95%CI 0.04-0.14), 308.83 (95%CI 106.46-872.82), and 0.983, respectively. The heterogeneity among 6 included studies was moderate for specificity (I-2 = 0.51) and low for sensitivity (I-2 = 0.17) and diagnostic OR (I-2 = 0.00). Conclusion D-SOC is associated with high sensitivity and specificity in the visual interpretation of indeterminate biliary strictures and malignancies. D-SOC should be considered routinely in the diagnostic workup of indeterminate biliary lesions.