Provocation of transient lower esophageal sphincter relaxations by gastric distension with air

Transient lower esophageal sphincter relaxations (TLESRs) are the major mechanism permitting not only gastroesophageal reflux but also venting of air from the stomach. Triggering of TLESRs is provoked by gastric distension. Antireflux surgery is associated with impaired ability to belch. It is not known whether a reduced capacity to belch results from postoperative reduction in TLESRs.

We studied the occurrence of TLESRs, common cavities (indicator for gas gastroesophageal reflux), and belching after standardized acute gastric distension by air insufflation (750 ml). Control subjects (n = 10), patients with gastroesophageal reflux disease (GERD) (n = 22), and patients after fundoplication (n = 24) were studied. LES and esophageal motilities were recorded with perfusion manometry.

Gastric distension with air significantly (p < 0.05) increased TLESR frequency in controls (1.6+/-0.3 to 3.5+/-1.0 per 20 min), GERD patients (1.2+/-0.3 to 3.1+/-0.5 per 20 min), and patients after fundoplication (0.5+/-0.1 to 1.8+/-0.6 per 20 min). Postfundoplication the number of TLESRs was significantly reduced (p < 0.05) both under fasting conditions and after air insufflation. The number of common cavities and belches after gastric air distension also was significantly reduced (p < 0.05) after fundoplication: 2.3+/-0.6 versus 4.7+/-0.4 in controls and 4.1+/-0.4 in GERD patients. About half of the common cavities occurred during TLESRs, and half during other mechanisms. An impaired ability to belch in daily life correlated with an impaired belching response during the test. An impaired ability to belch occurred only in patients with complete fundoplication and not in patients with partial fundoplication and was associated with a reduced number of common cavities after gastric air insufflation.

Short-lasting gastric air distension 1) provokes TLESRs but does not differentiate GERD patients from controls, 2) reveals impaired belching capacity in patients after complete fundoplication, and 3) shows that common cavities do not exclusively occur during TLESRs.