Excess gastroesophageal reflux in patients with hiatus hernia is caused by mechanisms other than transient LES relaxations  Margot A. Van Herwaarden, Melvin Samsom, André J.P.M. Smout  Gastroenterology  Volume 119, Issue 6, Pages 1439-1446 (December 2000) DOI: 10.1053/gast.2000.20191 Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 1 Effect of hiatus hernia on esophageal acid exposure. Patients with a hiatus hernia (▨) had significantly more esophageal acid exposure than patients without hiatus hernia (□) during the total 124-hour, postprandial, and daytime interprandial periods. *P < 0.03; **P < 0.01. Gastroenterology 2000 119, 1439-1446DOI: (10.1053/gast.2000.20191) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 2 Percentage of reflux episodes associated with the various motor mechanisms underlying acid reflux in patients with (▨) and without (□) hiatus hernia. Patients without hiatus hernia had a higher percentage of reflux episodes associated with TLESRs and SAPLESRs than patients with hiatus hernia. Patients with hiatus hernia had a higher percentage of reflux episodes related to SANLESR, low LES pressure, straining, and deep inspiration during periods with LES pressure ≤0.4 kPa. *P < 0.03; **P ≤ 0.005; ***P < 0.001. Gastroenterology 2000 119, 1439-1446DOI: (10.1053/gast.2000.20191) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 3 Effect of hiatus hernia on basal end-expiratory LES pressure. End-expiratory LES pressures were similar in patients with and without hiatus hernia. Gastroenterology 2000 119, 1439-1446DOI: (10.1053/gast.2000.20191) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 4 Absolute number of reflux episodes related to the motor mechanisms underlying acid reflux in patients with (▨) and without (□) hiatus hernia. Patients with hiatus hernia had numbers of reflux episodes associated with TLESRs and SAPLESRs similar to those in patients without hiatus hernia. The incidence of reflux episodes associated with low LES pressure, SANLESR, straining, and deep inspiration during periods with LESP ≤0.4 kPA was higher in patients with hiatus hernia. *P = 0.04; **P = 0.003; ***P < 0.001. Gastroenterology 2000 119, 1439-1446DOI: (10.1053/gast.2000.20191) Copyright © 2000 American Gastroenterological Association Terms and Conditions

Fig. 5 Relative contribution of the various LES motor patterns to total reflux time in GERD patients with and without hiatus hernia during the interprandial, postprandial, and supine periods. TLESRs and SAPLESRs were responsible for almost all reflux episodes in patients without hiatus hernia during the interprandial, postprandial, and supine periods. In patients with hiatus hernia, a more heterogeneous pattern was observed with marked differences between time periods. Values represent means. Values <1% are not shown. Gastroenterology 2000 119, 1439-1446DOI: (10.1053/gast.2000.20191) Copyright © 2000 American Gastroenterological Association Terms and Conditions