Assessing Bolus Retention in Achalasia Using High-Resolution Manometry With Impedance: A Comparator Study With Timed Barium Esophagram

OBJECTIVES: The aim of this study was to assess whether high-resolution impedance manometry (HRIM) could be used to assess bolus retention similar to the timed barium esophagram (TBE). METHODS: Twenty achalasia patients (10 males, aged 21 - 79 years) were prospectively evaluated with HRIM and TBE to determine the correlation between barium column height and the impedance bolus height (IBH). The TBE protocol used a 200-ml barium challenge and the HRIM protocol used a 200-ml saline challenge protocol. Both protocols were performed in an upright position and the heights of the barium and impedance columns were measured at 1 and 5 min. Analysis of IBH was performed with a topographic technique and a spatial impedance variation plot. RESULTS: There was no signifi cant difference between the median IBH and barium column at 1 min (IBH: 12.0 cm (interquartile range (IQR), 8.0 - 18.0); TBE: 12.0 cm (IQR, 7.0 - 19.0); P = 0.90) or at 5 min (IBH: 11.0 cm (IQR, 1.0 - 17.0); TBE: 9.0 cm (IQR, 4.0 - 12.0); P = 0.47). In addition, the correlation between the two measurements at 1 and 5 min was 0.60 and 0.86, respectively. Using a barium column or impedance height of > 5.0 as a definition of bolus retention was associated with 75 % concordance at 1 min and 95 % concordance at 5 min. CONCLUSIONS: There was excellent agreement between TBE and high-resolution impedance manometry (HRIM) for assessing bolus retention at 5 min. Thus, HRM with impedance may be used as a single test to assess bolus retention and motor function in the management of achalasia.