Confocal laser endomicroscopy for Barrett's esophagus and gastroesophageal reflux disease

Background: Confocal laser endomicroscopy (CLE) provides 'live' microscopic images of mucosal histology in the gastrointestinal tract. Two common gastrointestinal disorders, Barrett's esophagus (BE) and gastroesophageal reflux disease (GERD), present diagnostic challenges during evaluation with standard upper endoscopy (EGD). BE causes esophageal adenocarcinoma and detection of early neoplasia is difficult, since early neoplasia can be microscopic. GERD symptoms unresponsive to medications are common, leading to multiple additional tests. As CLE identifies microscopic detail, it may be useful for the evaluation of patients with Barrett's esophagus and GERD. Aims: 1) To determine whether CLE with optical biopsy and targeted mucosal biopsy (CLE-TB) improves the diagnostic yield of endoscopically inapparent, BE neoplasia compared to standard endoscopy with 4--quadrant random biopsies (SE-RB). 2) To characterize endomicroscopic features of GERD by comparing CLE findings in patients with normal and abnormal 48 hour wireless esophageal pH testing.;Methods: Patients with BE or unlocalized BE neoplasia underwent CLE-TB and SE-RB in randomized order. CLE-TB and SE-RB were compared for neoplasia yield and reduction in mucosal biopsies. GERD patients had EGD with CLE and 48 hour wireless pH testing. CLE features suspected of being associated with GERD were documented during the procedure. These features were compared between patients with normal and abnormal esophageal pH.;Results: In BE patients, CLE-TB almost doubled the diagnostic yield for neoplasia and reduced the number of biopsies needed for diagnosis, Two thirds of patients in the BE surveillance group did not need any mucosal biopsies due to absence of neoplasia on CLE imaging. In GERD patients, CLE features associated with abnormal esophageal pH included dilation of intercellular spaces, increased intrapapillary capillary loops, and leaking fluorescein.;Conclusion: CLE -TB significantly improved the yield for BE neoplasia compared to SE-RB. CLE also greatly reduced the mucosal biopsies needed per patient and allowed some patients to completely forgo mucosal biopsy, which may be beneficial. In GERD, several CLE image features are associated with abnormal esophageal pH. Technology improvements and further studies are needed if CLE is to be a viable alternative to other tests in patients with GERD that is not responsive to medical therapy.