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 × 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.