Assessment of esophageal motor function using combined multichannel intraluminal impedance and manometry in healthy volunteers: a single-center study in Taiwan

BACKGROUND: Combined multichannel intraluminal impedance and manometry (MII-EM) allow simultaneous measurement of both pressure and bolus transit. The aim of this study was to establish normative data in Chinese subjects for combined MII-EM and to correlate liquid and viscous bolus transit by impedance with esophageal contractions by manometry. METHODS: Eighteen normal volunteers (six women and 12 men; mean age 24 years, range 19-36 years) underwent combined MII-EM with a catheter containing four impedance-measuring segments and five solid-state pressure transducers. Each subject received 10 liquid and 10 viscous material swallows of 5 mL each. Tracings were analyzed for bolus presence time, total bolus transit time, contraction amplitude, duration, and onset velocity. RESULTS: A total of 180 liquid and viscous swallow responses were analyzed. In all, 98.4% percent of manometrically normal liquid and 97.7% of manometrically normal viscous swallows had complete bolus transit by impedance. More than half (56.3%) of manometrically ineffective liquid and 50% of ineffective viscous swallows had complete bolus transit. Nearly 90% of normal individuals had at least 70% complete liquid bolus transit while more than 90% of normal individuals had at least 70% complete viscous bolus transit. CONCLUSIONS: This study establishes normative data for combined MII-EM in a healthy Chinese population. These data will help provide impedance application in esophageal function testing with a reference range that could be utilized by future studies or clinical practices involving Chinese subjects.