Probe-based confocal laser endomicroscopy for the diagnosis of undetermined biliary stenoses: A meta-analysis

Presently, both the accuracy and sensitivity for distinguishing biliary stenosis from benign to malignant are low. In recent articles, the probe-based confocal laser endomicroscopy (pCLE) showed a better sensitivity than traditional methods in diagnosing malignant biliary stenosis. Here, we conducted a meta-analysis to summarise the published literature.

A systematic search for literature was conducted in the Medline, Embase and Cochrane Library databases published until November 2015. Further publications were found in the reference lists of the relevant articles. A quality assessment and data extraction were performed by two reviewers independently. A meta-analysis was performed to evaluate the diagnostic efficiency of a pCLE for discriminating benign and malignant biliary stenoses.

Eight studies involving 280 patients were included in the analysis. Significant heterogeneity in specificity was observed among the studies (Cochran's Q test=15.89, degrees of freedom [df]=7, P=0.0261 and I²=55.9%), while the heterogeneity in sensitivity was not obvious (Cochran's Q test=7.99, df=7, P=0.3334 and I²=12.4%). The area under the summary receiver operating characteristic (SROC) curve was 0.8968. The meta-regression and subgroup analysis indicated that the outlier was the source of heterogeneity. When analysed in the random-effects model, the pooled sensitivity, specificity, positive likelihood ratio (LR) and negative LR were 0.90 (0.84-0.94), 0.75 (0.66-0.83), 3.17 (2.18-4.61) and 0.17 (0.11-0.26), respectively. No significant publication bias was found in our research.

A pCLE is a valuable method for the differential diagnosis between malignant and benign biliary stenoses. However, a preferable diagnostic standard should be explored and improvements in specificity are required.