Transsphincteric pH profile at the gastroesophageal junction

Area of Science:

• Gastroenterology
• Esophageal Physiology
• Acid Reflux Research

Background:

• Conventional measurement of esophageal acid exposure is performed 5 cm above the lower esophageal sphincter (LES).
• The precise location of maximal acid exposure within the gastroesophageal junction remains incompletely understood.
• Understanding acid distribution is crucial for diagnosing and managing acid-related esophageal conditions.

Purpose of the Study:

• To compare pH profiles at multiple sites within the LES, distal esophagus, and proximal stomach.
• To evaluate acid exposure at sites closer to and within the LES compared to the standard measurement point.

Main Methods:

• Ten healthy subjects underwent esophageal manometry and 24-hour ambulatory pH monitoring.
• An 8-channel pH probe recorded data at 5 cm and 1.5 cm above, and at 0, 1.5, 3.0, 4.5, 6.0, and 9.5 cm below the proximal LES.
• A 4-hour gastric emptying test was conducted concurrently with pH monitoring.

Main Results:

• A progressive increase in acid exposure was observed from the esophageal to the gastric sensors.
• Acid exposure (pH < 4) was significantly higher at 1.5 cm above and within the LES compared to 5 cm above the LES.
• Intrasphincteric acidity increased postprandially, and gastric emptying correlated inversely with intragastric acidity.

Conclusions:

• Acid exposure is significantly underestimated when measured only 5 cm above the LES.
• High acid exposure within the intrasphincteric region may contribute to esophageal pathologies.
• These findings suggest a need to reconsider standard pH monitoring sites for improved diagnostic accuracy.