In vivo gastric mucosal histopathology using endocytoscopy

AIM:To study the ability of endocytoscopy to identify normal gastric mucosa and to exclude Helicobacter pylori(H.pylori) infection.METHODS:Endocytoscopic examination of the gastric corpus and antrum was performed in 70 consecutive patients.Target biopsy specimens were also obtained from the assessed region and multiple H.pylori tests were performed.The normal endocytoscopy patterns of the corpus and antrum were divided into the normal pit-dominant type(n-Pit) or the normal papilladominant type(n-Pap), respectively characterized as either regular pits with capillary networks or round, smooth papillary structures with spiral capillaries.On the other hand, normal mucosa was defined as mucosa not demonstrating histological abnormalities, including inflammation and atrophy.RESULTS:The sensitivity and specificity of n-Pit for normal mucosa in the gastric corpus were 94.4%and 97.1%,respectively,whereas those of n-Pap for normal mucosa in the antrum were 92.0%and 86.7%,respectively.The positive predictive values of n-Pit and n-Pap for H.pylori-negative tissue were 88.6%and 93.1%,respectively,and their negative predictive values for H.pylori-negative tissues were 42.9%and41.5%,respectively.The inter-observer agreement for determining n-Pit and n-Pap for normal mucosa were0.857 and 0.769,respectively,which is considered reliable.CONCLUSION:N-Pit and n-Pap,seen using EC,are considered useful predictors of normal mucosa and theabsence of H.pylori infection.

Microvasculature of the esophagus and gastroesophageal junction: Lesson learned from submucosal endoscopy

Advanced therapeutic endoscopy,in particular endoscopic mucosal resection,endoscopic submucosal dissection,per-oral endoscopic myotomy,submucosal endoscopic tumor resection opened a new era where direct esophageal visualization is possible.Combining these information with advanced diagnostic endoscopy,the esophagus is organized,from the luminal side to outside,into five layers(epithelium,lamina propria with lamina muscularis mucosa,submucosa,muscle layer,adventitia).A specific vascular system belonging to each layer is thus visible: Mucosa with the intra papillary capillary loop in the epithelium and the sub-epithelial capillary network in the lamina propria and,at the lower esophageal sphincter(LES) level with the palisade vessels; submucosa with the drainage vessels and the spindle veins at LES level; muscle layer with the perforating vessels; periesophageal veins in adventitia.These structures are particularly important to define endoscopic landmark for the gastro-esophageal junction,helpful in performing submucosal therapeutic endoscopy.