The Research Of The Diagnostic Value Of Gastric Cancer And Precancerosis By Confocal Laser Endomicroscopy

Background and aimsGastric cancer is the second commonest cause of cancer-associated death in the world.Recently,the incidence and mortality of gastric cancer are submitted rising tendency in our country.The pathogenesis of intestinal-type gastric cancer involves a multistep process,from chronic superficial gastritis to chronic atrophic gastritis,gastric mucosa intestinal metaplasia to gastric mucosa intraepithelial neoplasia and finally to gastric cancer.This is called correa rank. It is generally accepted that the gastric mucosa atrophy with IM or IN was precancerous lesion of gastric cancer.The early diagnosis of gastric carcinoma is more important to the next therapy.So far,the histopathological examination is necessary for the diagnosis of gastric cancer.Confocal laser endomicroscopy (CLE) has been developed which is integration of a confocal laser microscope in the distal tip of a conventional videoendoscope.The components enable confocal microscopy in addition to standard videoendoscopy.The new device can provide real-time,high magnification,cross-sectional images of the gastrointestinal surface and subsurface during routine endoscopy.Compared with other new optics technique,the greatest advantage of the CLE is that it can enable surface and subsurface imaging of living cells in the mucosa during ongoing endoscopy.The confocal images that approximately 1000-fold magnification readily permits single cells in the gastrointestinal tract to be resolved.The diagnostic value of gastric cancer and precancerous is still not clear. In this study we aim to identify cells and subcellular structures of normal, precancerous and cancer mucosa in CLE,definite the characteristic of confocal images,and evaluate the efficacy of CLE. MethodsCLE(Pentax EC-3870K,Pentax,Tokyo,Japan).Fluorescein sodium and acriflavine hydrochloride were used as contrast agent.Normal gastric mucosa in CLE:the patients with the normal mucosa by routine endoscopy in PLA general hospital digestive endoscopy centre were recruited.The three locations were examined by CLE respectively.Images of each lesion were acquired and stored digitally,and in vivo diagnosis was performed during ongoing endoscopy.Biopsy specimens were taken from every lesion.Gastric mucosa atrophy with IM in CLE:the patient with previous history of chronic gastritis and suspected the CAG with GIM were recruited and underwent routine endoscopy and CLE respectively.The targeted biopsies were obtained at the same location.The results of video endoscopic images,confocal endoscopic images and biopsy pathology were compared respectively.The CLE and NBI-ME in IN:The patients with IN by routine endoscopy and histopathology were recruited and underwent NBI,NBI-ME and CLE respectively.Then ESD was performed in these patients.Evaluate the images features of IN with NBI and CLE by Control study.To evaluate the application of confocal laser endomicroscopy(CLE) for diagnosis gastric mucosa atrophy with IM in vivo.The results of biopsy pathology and ESD pathology were compared.The CLE in benign and malignant gastric ulcer:the patients with gastric ulcer or cancer by routine endoscopy were recruited.The benign or malignant ulcer could be distinguished according to the CLE images.Compared with the histopathology,the confocal features of cancerous differentiation could be described.1.The confocal images of normal gastric mucosa were obtained from 30 patients.In the CLE,The gastric pits of the stomach,columnar epithelium cells, connective tissue and capillaries could be visualized. Gastric fundus:superficial lamella gastric pits were round.Few pits composed one unit.Edge crack was lines.Net-like subepithelial capillary network patterns were surrounding the gastric pits.Gastric body:The gastric pits were round.Honeycomb-like subepithelial capillary network patterns were surrounding the gastric pits.Gastric antrum:The gastric pits were lines type.Coil-shaped subepithelial capillary network patterns were surrounding the gastric pits.2.75 route imaging were obtained from 42 patients and 150 pieces biopsy specimens from 75 locations.The final diagnoses among the total 30 pieces from 8 patients were CAG with IM.7200 confocal imaging were obtained from 42 patients and 150 pieces biopsy tissues from 75 locations.The final diagnoses among the total 48 pieces from 16 patients were CAG with IM.1) CAG in CLE showed the decreasing number of asymmetric gastric pits and the widen bright interspaces.2) GIM in CLE was identified if any of following three features were present in an image field:goblet cells,columnar absorptive cells,brush border, and villiform foveolar epithelium.3.18 locations from 16 patients with IN were recruited.12 HGIN and 6 LIN were diagnosed by NBI and NBI-ME.10 HGIN and 8 LIN were diagnosed by CLE.8 HGIN and 10 LIN were diagnosed by pathologic diagnosis after ESD.1) NBI and NBI-ME images in IN:LIN showed that the irregular pits,the architecture of gastric pits lost and the unclear defective delimitation.HGIN showed that the lost gastric pits lost and irregular capillaries.There were granular tuberositas and paraplasm on the pits.2) Confocal images in IN:LIN showed that the different sizes of gastric pits,any capillary network are thickening and circuitous. HGIN showed that abnormal arrange of gastric pits and the thickening capillary network.The increasing branch of blood vessels presented mass shape.4.27 patients with ulcer type lesion by routine endoscopy were recruited.8 benign ulcers and 19 malignant ulcers were diagnosed by CLE and histopathology.Among the 19 malignant ulcers,5 differentiated-type and 14 undifferentiated-type were diagnosed by CLE and histopathology.1) Benign gastric ulcer showed in CLE that basic feature of gastric pits had no change.The effusion of fluorescein sodium increased.The shapes of blood vessel were normal.Malignant gastric ulcers showed in CLE that the structure of gastric pits are disappear.Heterocyst is large and black.Capillary network is distortion and interrupted.2) Differentiated type includes high-differentiated and moderately differentiated adenocarcinoma.Undifferentiated type includes low-differentiated adenocarcinoma and signet-ring cell cancer.Differentiated type gastric cancer showed in CLE that the different sizes and shapes heterotypic gland organs replaced the normal structures gastric pits. The heterocyst could be seen.The capillary networks were increased and circuitous.Undifferentiated type gastric cancer showed in CLE that lost the gastric pits structures,the black and large heterocyst and the decreasing capillary networks.ConcludeCLE is a novel developed diagnostic tool to enable virtual histology in vivo during ongoing endoscopy,and is a new method to predict CA,GIM and IN with high accuracy,and identify the diagnosis between benign and malignant ulcer, and make a pre-judgment of differentiated degree of gastric cancer.