Postprandial proximal gastric acid pocket in patients after laparoscopic Nissen fundoplication.

Background: An unbuffered postprandial proximal gastric acid pocket (PPGAP) has been noticed in normal individuals and patients with gastroesophageal reflux disease (GERD). The role of gastric anatomy in the physiology of the PPGAP remains unclear. It is also unclear whether change in the PPGAP may contribute to GERD control. This study aims to analyze the presence of PPGAP in patients submitted to Nissen fundoplication.

Methods: Fifteen patients who had a laparoscopic Nissen fundoplication (mean age = 61 years, 13 females, mean time from operation 1 year) were studied. All patients were free of foregut symptoms. Patients underwent high-resolution manometry to identify the location of the lower border of the lower esophageal sphincter (LBLES).Station pull-through pH monitoring was performed from 5 cm below the LBLES to the LBLES in increments of 1 cm in a fasting state and 10 min after a standardized fatty meal.

Results: Four patterns of gastric acidity were found: (1) acid was not detected in the studied area of the stomach in 8 (53%) patients; (2) constant acidity (stomach is not alkalinized after meal), i.e., a buffered layer was not found in 3 (20%) patients; (3) PPGAP was not detected, i.e., the whole stomach is alkalinized, in 1 (7%) patient; and (4) PPGAP was noted in 3 (20%) patients with extensions of 2, 2, and 5 cm.

Conclusion: PPGAP is present in a minority of patients after Nissen fundoplication. This finding may explain part of the GERD control and that the gastric fundus may play a role in the genesis of the PPGAP.