Assessment of gastric volume changes with sonometry compared with barostat

AIM: The aim was to investigate the validity of sonometry on the assessment of gastric volumes in comparison with gastric barostat. METHOD: Six dogs were implanted with gastric serosal electrodes, sonometric sensors, and a gastric cannula. Experiments were performed to assess sensor distance when an intragastric balloon was inflated with different volumes, after a meal with or without a balloon, and with gastric electrical stimulation. RESULTS: (i) The distance measured using sonometry was reproducible and stable, and there was a correlation between sensor distance and the gastric volume measured with barostat. (ii) Simultaneous recordings by sonometry and barostat showed a similar postprandial response, while the postprandial increase of the sensor distance was much smaller without the balloon (3.2+/-0.2 mm vs 9.7+/-1.5 mm, P<0.02). (iii) The sensor distance was increased with gastric electrical stimulation. CONCLUSIONS: Sonometry is able to detect gastric volume changes as validated by gastric perturbations with distensions, food ingestion and electrical stimulation. The postprandial increase in gastric volume measured by sonometry with barostat balloon is greater because of the presence of the intragastric balloon.