Use of probe-based confocal laser endomicroscopy (pCLE) in gastrointestinal applications. A consensus report based on clinical evidence

Abstract

Background: Probe-based confocal laser endomicroscopy (pCLE) provides microscopic imaging during an endoscopic procedure. Its introduction as a standard modality in gastroenterology has brought significant progress in management strategies, affecting many aspects of clinical care and requiring standardisation of practice and training.

Objective: This study aimed to provide guidance on the standardisation of its practice and training in Barrett's oesophagus, biliary strictures, colorectal lesions and inflammatory bowel diseases.

Methods: Initial statements were developed by five group leaders, based on the available clinical evidence. These statements were then voted and edited by the 26 participants, using a modified Delphi approach. After two rounds of votes, statements were validated if the threshold of agreement was higher than 75%.

Results: Twenty-six experts participated and, among a total of 77 statements, 61 were adopted (79%) and 16 were rejected (21%). The adoption of each statement was justified by the grade of evidence.

Conclusion: pCLE should be used to enhance the diagnostic arsenal in the evaluation of these indications, by providing microscopic information which improves the diagnostic performance of the physician. In order actually to implement this technology in the clinical routine, and to ensure good practice, standardised initial and continuing institutional training programmes should be established.

Keywords: Barrett’s oesophagus; Endomicroscopy; advanced endoscopy; biliary strictures; colorectal polyps; credentialling; gastroenterology; inflammatory bowel diseases; optical biopsy; recommendations; small polyps; training.

Figures

Figure 1.

Methodology workflow. IBD: inflammatory bowel diseases.

Figure 2.

Diagrammatic representation of the concordance between the level of agreement and the grade of evidence, as estimated by experts (r represents the Spearman’s rank correlation coefficient). Each point represents one statement; larger points represent two or three statements with the same data. ‘Agreement’ means ‘strong or moderate agreement’ and ‘evidence’ means ‘strong or moderate evidence’ (– or – –, see Table 1). The light-grey areas represent the statements with the highest levels of agreement and evidence. Dark-grey areas correspond to the statements rejected with the lowest grade of evidence. Globally, biliary strictures and BE showed the best performances, whereas colorectal lesions showed the least satisfying performance.

Figure 3.

Probe-based confocal laser endomicroscopy (pCLE) pictures showing: (a) non-dysplastic Barrett’s oesophagus with goblet cells easily identified, regular columnar-lined epithelium, equidistant glands and regular and equidistant cells, and (b) Barrett’s oesophagus with early oesophageal adenocarcinoma with goblet cells not easily identified and loss of structure.

Figure 4.

Probe-based confocal laser endomicroscopy (pCLE) pictures showing: (a) healthy bile duct mucosa with a reticular network of thin dark branching bands and a grey background, and (b) malignant bile duct mucosa (cholangiocarcinoma) with epithelial borders.

Figure 5.

Probe-based confocal laser endomicroscopy (pCLE) pictures showing: (a) healthy colon mucosa with round crypt structures and dark goblet cells, and (b) hyperplastic lesion with crypts with slit or stellate openings surrounded by uniform epithelium and goblet cells.

Figure 6.

Probe-based confocal laser endomicroscopy (pCLE) pictures showing: (a) inflamed colon mucosa with difference in shape, size and distribution of crypts, increase of capillaries dilated and distorted and cellular infiltration, and (b) dysplastic colon mucosa with ridged-lined irregular epithelial layer with loss of crypts and goblet cells and irregular cell architecture with little or no mucin. Dilated and distorted vessels with increased leakage could also be observed.