547 A Study On the Intercellular Space of Squamous Epithelium in Lower-Esophagus with Light Microscopy in the Diagnosis of GERD

Abstract

(between 53.0 and 66.4%) or alkaline (between 0.5 and 1.3%) was similar in all groups. However, the median nadir pH of reflux episodes decreased with increasing severity of mucosal damage and was highest in the controls (pH 3.8) and lowest in the patients with Barrett (pH 2.5). Besides an increased number of reflux episodes, the acid clearance time of the acid reflux episodes was significantly longer in the patients with severe esophagitis (134±20 s) and Barrett's esophagus (104±21 s) compared to the controls (58±30 s), patients with NERD (73±14 s), LA A (84±49 s) and LA B (70±35 s). Comparison with normal values revealed that none of the controls, 40% of the patients with NERD, 50% of the patients with LA A, 80% of the patients with LA B and all patients with LA C/D or Barrett's esophagus had an abnormally high total number of reflux episodes. In the patients with severe esophagitis a significantly higher percentage of reflux episodes reached the proximal esophagus (43.8%) compared to the patients with Barrett's esophagus (19.2%). Conclusions: Not only the number of acid reflux episodes but also the number of weakly acidic reflux episodes is increased in patients with increasing severity esophagitis and Barrett's esophagus. However, a large overlap between the groups exists which implies that comparison to normal values is of limited relevance. In patients with Barrett's esophagus fewer reflux episodes reach the (more sensitive) proximal esophagus which might explain their low sensitivity to reflux.