Evaluation Of The Diagnostic Yield Of Goblet Cells For Gastric Intestinal Metaplasia Under The Confocal Laser Endomicroscopy

BackgroundIn China, gastric cancer is still of high morbidity and mortality among malignant tumors, which can be decreased significantly by early detection. It is generally accepted that gastric cancer is developed by the "atrophic gastritis-intestinal metaplasia-dysplasia-gastric cancer" mode, which is called Correa sequence. Therefore, gastric intestinal metaplasia (GIM) is regarded as an important precancerous lesion. However, many researchers show that conventional endoscopic identification of GIM has a high rate of interobserver variability and correlates poorly with the histological findings, even if with the application of chromoendoscopy, such as methylene blue or indigo carmine staining.Confocal laser endomicroscopy (CLE) is a newly developed endoscopic imaging technique which helps us get histopathologic pictures of gastric mucosa and submucosa, without biopsy during ongoing endoscopy and allows targeted biopsies. Several investigators have reported that the technique is of value for identifying and classifying GIM with high accuracy and sensitivity.ObjectiveTo evaluate the diagnostic yield of the goblet cells for gastric intestinal metaplasia under confocal laser endomicroscopy, and also evaluate its interobserver agreement retrospectively, which aim to simplify the diagnostic criteria of the GIM under CLE. Materials and methodsPatients:Between April 2008 and September 2009,95 patients were enrolled in the study, including 70 patients(45 males and 25 females, mean age 55.87±10.98) with biopsies identified GIM and 25 patients(16 males and 9 females, mean age 54.40±10.79) with biopsies identified acute or chronic inflammation.Consecutive patients with long-term upper gastrointestinal syndromes were involved, also the patients with known GIM or suspected GIM.The exclusion criteria were as follows:below 18 or above 60 years of age; a history of bronchial asthma, or known allergy to fluorescein sodium; severe inflammation of the stomach; pregnant or breast-feeding; non-correctable coagulopathy; severe co-morbidities (e.g. such as renal failure, congestive cardiac failure and liver cirrhosis).All procedures were performed using a Pentax EC3870K endomicroscope (Pentax, Tokyo, Japan) by an experienced endoscopist. After injection of 5ml of 0.1 g/ml fluorescein sodium, the macroscopic lesions or suspected lesions labeled by suction were observed carefully by CLE. Then the CLE images were stored and target biopsies were performed. The pictures for evaluation were selected by another experienced endoscopist, according to the requirement:1. all lesions with histopathologic diagnosis; 2.6-8 consecutive clear pictures.All selected CLE images were displayed and evaluated by two groups of observers (Experienced Endoscopists.EE and Inexperienced Endoscopists.IE) who were blinded to the patients'endoscopic findings and histology. The two groups of evaluators were required to make a judgment that whether there is GIM or not of the picture according to the current diagnostic criteria, and the chosen diagnostic parameters should be marked in the table.ResultsAccording to the current diagnostic criteria, the coincidence rate of EE and IE are 92.14%,82.57%respectively, the coincidence rate of goblet cells, villiform shape, brush border, columnar absorptive cells, goblet cells+villiform shape, goblet cells+ brush border, goblet cells+columnar absorptive cells are 80.46%,51.53%,39.27%, 61.69%,86.78%,81.71%respectively. So we can see that the goblet cells+villiform shape has the best diagnostic yield, then the goblet cells+columnar absorptive cells.Conclusions1. The current diagnostic criterion of GIM under CLE is of great diagnostic yield to the both experienced endoscopists and inexperienced endoscopists.2. The accuracy when we only use goblet cells as the diagnostic criteria could be more than 80%, but if we use the combined indexes, the accuracy could be higher.3. The goblet cells and columnar absorptive cells have a good interobserver agreement, while the interobserver agreement of villiform shape and brush border are low.4. In clinical use, we could regard the goblet cells as the screen index for GIM, which could be accurate in more than 80%, the accuracy could be increased to 90% around by the combination of villiform shape and columnar absorptive cells.