Impedance characteristics of normal oesophageal motor function.

OBJECTIVE: To obtain detailed data about the correlation between oesophageal peristalsis and bolus transport for clinical oesophageal motility testing.
METHODS: Oesophageal motility testing was performed in 25 healthy subjects by using the newly developed technique of concurrent impedancometry and manometry. Parameters of oesophageal motility and bolus transport as well as the correlation between transit and motility were analysed after swallowing saline or yogurt.
RESULTS: Detailed data about bolus transport and oesophageal motility could be obtained during a single investigation step. Air was observed in front of the bolus in 76% of the swallows. Resting baseline impedance was significantly higher in the oesophagus than in the stomach (2832+/-118 Omega vs 688+/-119 Omega). The deglutitive impedance gradient was 222+/-26 Omega for saline and 482+/-38 Omega for yogurt. Bolus propagation velocity and bolus transit time as impedance parameters of bolus transport discriminated fluid from semisolid bolus (4.0+/-0.1 cm/s vs 3.2+/-0.1 cm/s and 9.9+/-0.2 s vs 11.5+/-0.2 s, for saline vs yogurt), while contraction wave amplitude as a manometry parameter of oesophageal motor function did not (91.4+/-7.5 mmHg vs 80.7+/-9.4 mmHg, for saline vs yogurt). There was a poor correlation between bolus propagation velocity and contraction wave amplitude.
CONCLUSIONS: Impedance parameters of normal oesophageal motor function have been characterized. Impedancometry and manometry provide different but complementary data about oesophageal motor function. Concurrent impedancometry and manometry allows detailed monitoring of oesophageal motility and bolus transit, which may open new perspectives for comprehensive oesophageal motility testing.