Background: Transient lower esophageal sphincter relaxations (TLESRs) are triggered by gastric distension. The aim of the study was to investigate TLESRs during controlled prolonged gastric distensions using the barostat technique.
Methods: Twelve healthy volunteers (4 M, 8 F, age range 19-42 years) were studied under fasting conditions with combined esophageal manometry (Dentsleeve) and gastric barostat. Randomized isobaric distensions at 0 (control), 10, 12 and 14 mmHg were performed each period for 30 min with 30-min recovery periods in between.
Results: The frequency of TLESR was significantly (P < 0.05) higher during all distension periods compared to control periods (4.0 +/- 0.4 TLESR/30 min versus 2.6 +/- 0.4 TLESR/30 min). The frequency of TLESR in the first 15-min period of distension was significantly (P < 0.001) higher compared to the second 15-min period pointing to adaptation (2.7 +/- 0.3 TLESR/15 min versus 1.3 +/- 0.2 TLESR/15 min, respectively). The frequency of TLESR correlated significantly with intragastric pressure (r = 0.47; P < 0.01) and wall tension (r = 0.48; P < 0.01), but not with intragastric volume. TLESR characteristics such as duration were not related to pressure or wall tension.
Conclusions: Acute gastric distension increases the frequency of TLESR but adaptation occurs rapidly. The frequency of TLESR during distension is related to pressure and wall tension rather than to intragastric volume.