Provocation of transient lower esophageal sphincter relaxations by gastricdistension with air

OBJECTIVES: Transient lower esophageal sphincter relaxations (TLESRs) are t he major mechanism permitting not only gastroesophageal reflux but also ven ting of air from the stomach. Triggering of TLESRs is provoked by gastric d istension. Antireflux surgery is associated with impaired ability to belch. It is not known whether a reduced capacity to belch results from postopera tive reduction in TLESRs. METHODS: We studied the occurrence of TLESRs, com mon cavities (indicator for gas gastroesophageal reflux), and belching afte r standardized acute gastric distension by air insufflation (750 ml). Contr ol 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. RESULTS: Gast ric 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 w as 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 fundoplicati on: 2.3 +/- 0.6 versus 4.7 +/- 0.4 in controls and 4.1 +/- 0.4 in GERD pati ents. About half of the common cavities occurred during TLESRs, and half du ring 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 pa tients with partial fundoplication and was associated with a reduced number of common cavities after gastric air insufflation. CONCLUSIONS: Short-last ing gastric air distension 1) provokes TLESRs but does not differentiate GE RD patients from controls, 2) reveals impaired belching capacity in patient s after complete fundoplication, and 3) shows that common cavities do not e xclusively occur during TLESRs. (C) 2001 by Am. Coll. of Gastroenterology.