Efficacy of EUS-guided needle-based confocal laser endomicroscopy in the diagnosis of pancreatic lesions: A systematic review and meta-analysis

Background and Objectives: Needle-based confocal laser endomicroscopy (nCLE) is a procedure in which an AQ-Flex nCLE mini-probe is passed through an EUS-FNA needle into a pancreatic lesion to enable subsurface in vivo tissue analysis. In this study, we conducted a systematic review and meta-analysis of nCLE for the diagnosis of pancreatic lesions. Materials and Methods: We conducted a comprehensive search of several databases and conference proceedings, including PubMed, EMBASE, Google-Scholar, MEDLINE, SCOPUS, and Web of Science databases (earliest inception to March 2020). The primary outcomes assessed the pooled rate of diagnostic accuracy for nCLE and the secondary outcomes assessed the pooled rate of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and adverse events (AE) of nCLE to diagnose premalignant/malignant pancreatic lesions. Results: Eleven studies on 443 patients were included in our analysis. The pooled rate of diagnostic accuracy of EUS nCLE was 83% (95 confidence interval [CI] = 79-87; I 2 = 0). The pooled rate of sensitivity, specificity, PPV and NPV of EUS nCLE was 85.29% (95% CI = 76.9-93.68; I 2 = 85%), 90.49% (95% CI = 82.24-98.74; I 2 = 64%), 94.15% (95% CI = 88.55-99.76; I 2 = 68%), and 73.44% (95% CI = 60.16-86.72; I 2 = 93%), respectively. The total AE rate was 5.41% (±5.92) with postprocedure pancreatitis being the most common AE at 2.28% (±3.73). Conclusion: In summary, this study highlights the rate of diagnostic accuracy, sensitivity, specificity, and PPV for distinguishing premalignant/malignant lesions. Pancreatic lesions need to be further defined with more validation studies to characterize CLE diagnosis criteria and to evaluate its use as an adjunct to EUS-FNA.