Transsphincteric pH Profile at the Gastroesophageal Junction Jyothi Mekapati, Linda C. Knight, Alan H. Maurer, Robert S. Fisher, Henry P. Parkman  Clinical Gastroenterology and Hepatology  Volume 6, Issue 6, Pages 630-634 (June 2008) DOI: 10.1016/j.cgh.2008.01.003 Copyright © 2008 AGA Institute Terms and Conditions

Figure 1 (A) Eight-probe pH recording assembly traversing the gastroesophageal junction with pH probes positioned 5 and 1.5 cm above the proximal manometric border of the LES, at the LES (0 cm), and 1.5, 3.0, 4.5, 6.0, and 9.5 cm below the proximal manometric border of the LES. (B) Radiographic image of the 8-probe pH recording assembly traversing the gastroesophageal junction in a normal study subject. Clinical Gastroenterology and Hepatology 2008 6, 630-634DOI: (10.1016/j.cgh.2008.01.003) Copyright © 2008 AGA Institute Terms and Conditions

Figure 2 Intraluminal pH recording from 8 pH probes positioned at 5 and 1.5 cm above and at 0, 1.5, 3.0, 4.5, 6.0, and 9.5 cm below the proximal LES border. The top tracing is 5.0 cm proximal to the proximal manometric border of the LES; whereas the bottom tracing is 9.5 cm distal to the proximal manometric border of the LES. This tracing is a 6-hour period from 4 pm to 10 pm. The shaded yellow area is the meal ingestion period of dinner—a turkey sandwich. The proximal sensors are recording a pH of around 6 during the fasting period, but then the pH has frequent, multiple excursions of less than 4 during the meal and for the 1- to 2-hour period thereafter. Clinical Gastroenterology and Hepatology 2008 6, 630-634DOI: (10.1016/j.cgh.2008.01.003) Copyright © 2008 AGA Institute Terms and Conditions

Figure 3 Composite results of 24-hour intraluminal pH recordings from 8 sites traversing the gastroesophageal junction in 10 normal subjects. The vertical axis represents the percentage of time that the intraluminal pH was less than 4 for the entire recording period. The horizontal axis represents the location of each of 8 pH recording probes. Acid exposures at the 3 intrasphincteric sites (0, 1.5 cm, and 3 cm beyond the proximal border of the LES) were significantly higher than in the distal esophagus and significantly lower than in the proximal stomach. The total percentage of acid exposure correlated significantly with the position of the pH probes (r = 0.95; P < .01). Each bar represents the mean ± SEM. Blue, total; red, upright; yellow, recumbent. Clinical Gastroenterology and Hepatology 2008 6, 630-634DOI: (10.1016/j.cgh.2008.01.003) Copyright © 2008 AGA Institute Terms and Conditions

Figure 4 Relationship between gastric retention of a standardized scrambled egg meal and intragastric acidity. The horizontal axis represents the time in minutes after ingestion of the radiolabeled meal. The vertical axis represents the values for both curves: intragastric [H] ions 6 cm below the proximal manometric border of the LES (diamond markers) and the percentage retention of the radiolabeled meal (square markers). While the meal was in the stomach intragastric acid was buffered by the meal, but as the meal emptied the stomach acidity increased as indicated by increased hydrogen ion concentration (diamond markers). Gastric emptying as indicated by percent retention of the egg meal, was correlated inversely with intragastric acidity (r = −0.818). Clinical Gastroenterology and Hepatology 2008 6, 630-634DOI: (10.1016/j.cgh.2008.01.003) Copyright © 2008 AGA Institute Terms and Conditions