To assess diagnostic accuracy and clinical effectiveness including cost-effectiveness analysis of pCLE in patients after finishing the endoscopic treatment of BORN in detecting persistent/recurrent IM, recurrent neoplasia and buried glands.

Confocal laser endomicroscopy (CLE) has been developed to overcome the limitations of the current endoscopic sampling techniques. CLE allows detailed examination of cellular structures since it provides images very similar to images which a pathologist can see in the microscope. At present, probe based CLE (pCLE) is the only available technology of endomicroscopy. Before optical biopsy, a fluorescein is given intravenously and then fluorescent light coming from a horizontal special focal plane is detected during pCLE of the digestive system.

CLE provide real-time histopathological diagnosis and can lead to an immediate endoscopic treatment in case of early esophageal and gastric neoplasia.

Patients after treatment of Barrett's esophagus related esophageal neoplasia (dysplasia or early cancer) should be surveilled endoscopically with biopsies to rule out relapse of Barrett's esophagus or neoplasia.

Project A - pCLE in the detection of esophageal and gastric lesions:

We plan to investigate the diagnostic accuracy of pCLE (compared to standard histopathology) in patients with endoscopically diagnosed early esophageal and gastric lesions.

Project B - pCLE in the detection of persistent/recurrent intestinal metaplasia/dysplasia in patients after endoscopic treatment of BORN:

Investigators plan to perform a prospective cross-over study comparing the diagnostic accuracy and sensitivity of pCLE with standard biopsies in patients after completed endoscopic treatment of BORN. Surveillance endoscopies are focused on detection of persistent/recurrent IM or dysplasia (ev. neoplasia). BORN is defined as low-grade dysplasia (confirmed by a specialized esophageal pathologist) or as high grade dysplasia or early adenocarcinoma. Investigators will also examine the ability of pCLE to detect buried glands after radiofrequency ablation.

Methods:

Project A:

Patients referred to our department with a suspect and endoscopically visible lesion in the esophagus or stomach will undergo pCLE during a standard upper GI endoscopy with pCLE. After a real-time diagnosis (made by the endoscopist), the standard tissue sampling (biopsies, endoscopic resection or dissection) followed by a standard histopathological tissue assessment will follow.

Project B:

During one of surveillance endoscopies in patients after finishing the endoscopic treatment of BORN (interval depends on baseline diagnosis), pCLE will be performed in the cardia, neo-Z-line, esophagus body and visible lesions, and images will be stored. Thereafter, standard biopsies will be taken and sent for histopathological analysis.

For optical biopsy, endoscopist (real time) and two expert pathologists will independently blindly evaluate each "optical specimen". The standard biopsy specimen will be assessed independently by a pathologist not assessing the optical biopsy. Results of optical biopsy will be compared with results of standard biopsy.

Main hypothesis:

Project A:

pCLE is not inferior to standard biopsy (or resection) specimen in histopathological diagnosing of esophageal/gastric lesions.

Project B:

pCLE is not inferior compared to standard biopsies in detecting persistent/recurrent IM, recurrent neoplasia and buried glands.

Inclusion Criteria:

• age > 18
• macroscopic lesion of esophagus or stomach (Project A)
• pts after ER/ESD/RFA for BORN (Project B)
• eradication of BORN and Barrett's esophagus macro- and microscopically (Project B)
• sign agreement with study

Exclusion Criteria:

• macroscopic persistence of Barrett's esophagus (e.g. tongues)
• esophageal varices
• treatment with anticoagulants
• allergy to fluorescein
• polyvalent allergy
• pregnancy