Phase concept: Novel dynamic endoscopic assessment of intramural antireflux mechanisms (with video).

Objectives: The gastroesophageal junction (GEJ) consists of various anatomical components that together form a barrier to prevent reflux of gastric content. This study introduces a novel phase concept to dynamically evaluate the antireflux barrier (ARB) during endoscopy and analyzes its functionality.
Methods: We reviewed previously the recorded endoscopic videos of subjects who underwent the endoscopic pressure study integrated system (EPSIS) from February to April 2024 for indications other than gastroesophageal reflux disease symptoms. This device was used as an auxiliary tool to measure intragastric pressure (IGP) during endoscopy with a retroflex view. The ARB dynamic was divided into three phases: Phase I (gastric phase), Phase II (lower esophageal sphincter phase), and Phase III (esophageal clearance phase). We evaluated the morphological changes in the ARB during insufflation using EPSIS.
Results: The median age of the 30 subjects was 58 years (interquartile range [IQR] 46.5-68.8), including 20 men and 10 women. Endoscopic findings and IGPs were recorded during the three phases. In Phase I, at low IGP (median 6.75 mmHg), the gastroesophageal flap valve and longitudinal folds were observed in 80% of cases. In Phase II, at moderate IGP (median 11.8 mmHg), the scope holding sign was observed in 86.7%. In Phase III, at high IGP (median 19 mmHg) inducing belching, peristalsis was observed in 80% of cases with median recovery time of 5 s.
Conclusion: The phase concept provides a valuable framework for understanding the antireflux mechanism. Further research is needed to validate these findings in GEJ disorders and explore correlations with other modalities.
(© 2024 The Author(s). Digestive Endoscopy published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)