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

Abstract

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). 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. There was no significant 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. 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.