Diagnosis of Biliary Strictures Using Probe-Based Confocal Laser Endomicroscopy under the Direct View of Peroral Cholangioscopy: Results of a Prospective Study (with Video)

Abstract

Background. The accurate diagnosis of biliary strictures remains problematic. The aim of the present study was to prospectively evaluate the clinical utility of probe-based confocal laser endomicroscopy (pCLE) under the direct view of peroral cholangioscopy (POCS) for the diagnosis of biliary strictures. Methods. Consecutive patients with biliary strictures were included. We investigated sensitivity, specificity, and accuracy to diagnose malignancy for (1) ERCP alone, (2) POCS, (3) pCLE under the direct view of POCS, and (4) tissue sampling under the direct view of POCS. Results. A total of 30 patients (17 with malignant lesions) were prospectively enrolled. (1) ERCP alone showed 88.2% sensitivity, 46.2% specificity, and 70% (95% confidence interval (CI), 52.1%–83.3%) accuracy. (2) POCS showed 100% sensitivity, 76.9% specificity, and 90% (95% CI, 74.4%–96.5%) accuracy. (3) pCLE under the direct view of POCS showed 94.1% sensitivity, 92.3% specificity, and 93.3% (95% CI, 78.7%–98.8%) accuracy. (4) Tissue sampling under the direct view of POCS showed 82.4% sensitivity, 100% specificity, and 90% (95% CI, 74.4%–96.5%) accuracy. Conclusions. pCLE under the direct view of POCS provided highly accurate and sensitive characterization of biliary strictures and showed the potential for more diagnostic reliability and reduction of delays in diagnosis. This trial was registered at UMIN (registration number: UMIN000033801).

Diagnostic Process Using Endoscopy for Biliary Strictures: A Narrative Review

“…Although pCLE can be performed both under fluoroscopy guidance or direct view with POCS, the pCLE findings under direct view with POCS can be accurately matched with biopsy tissue. Therefore, these results could be diagnostically more reliable [58,64].…”

“…Benign findings include: (i) a fine network of thin vessels and a flat surface with or without shallow pseudodiverticula; (ii) a lower homogeneous papillogranular surface without primary masses, suggesting hyperplasia; (iii) a bumpy surface with or without pseudodiverticula, suggesting inflammation; and (iv) a white surface with a convergence of folds, suggesting scarring. Table 3 provides the data on the diagnostic yield of POCS visual findings for indeterminate biliary strictures [37,41,48,49,[54][55][56][57][58]. The sensitivity for malignancy is in the range of 83-100%, the specificity is 67-96%, and the accuracy is 85-96%.…”

“…Table 3 also provides data on the diagnostic yield of POCS-guided biopsy for indeterminate biliary strictures. The sensitivity for malignancy is in the range of 64-86%, the specificity is 89-100%, and the accuracy is 70-90% [37,41,48,49,[54][55][56][57][58]. In a systematic review and meta-analysis of the diagnostic yield of the POCS-guided biopsy, the pooled sensitivity and specificity for diagnosing ma-lignant biliary strictures were 60.1% (95% CI (54.9-65.2%)) and 98.0% (95% CI (96.0-99.0%)), respectively [59].…”

“…Subsequently, to solve the problem of false-positive cases (such as inflammation) as a result of using the Miami classification, the Paris classification was created [66]. Table 4 provides the data on the diagnostic yield of pCLE for biliary strictures [58,[64][65][66][67][68]. The sensitivity for malignancy is in the range of 83-98%, the specificity is 33-93%, and the accuracy is 78-93%.…”

Recent advances of diagnostic approaches for indeterminate biliary tract obstruction

“…Therefore, these results could be diagnostically more reliable. 38,39 The Miami classification was initially created to differentiate malignant and benign tumors. 40 The criteria for the diagnosis of malignancy are listed as follows:…”