Swallowing

High resolution manometry

Supine position

Geology

Bolus (digestion)

Radiology

Internal medicine

Esophagus

Remote sensing

High resolution

Medicine

Saline

Nuclear medicine

Peristalsis

Fluoroscopy

Achalasia

Neurogastroenterology & Motility

Background This study aimed to develop a methodology for quantifying esophageal bolus retention using a high‐resolution esophageal impedance topography ( EIT ) technique. Methods The ability of impedance to quantify bolus retention was validated by comparison with concurrent fluoroscopic imaging (barium bolus) in 10 healthy subjects. High‐resolution impedance manometry ( HRIM ) studies without fluoroscopy were performed in another 15 healthy subjects to define normal values using saline. HRIM data from each subject were analyzed using a MATLAB program customized for calculating the esophageal impedance integral ( EII ) prior to the contraction wave front as EII 1 and after the contraction as EII 2, and presented as a ratio of EII 2/ EII 1, which was compared to the percent of barium areas retained in the esophagus on fluoroscopy determined by a blinded reviewer. Key Results In 93% (37/40) of barium swallows, the results from the EIT method were in agreement with fluoroscopy results with one of three patterns: (1) 25 normal bolus transit, (2) eight bolus stasis, and (3) four retrograde escape or reflux. Three swallows (8%) had slight retention identified by EIT , but no retention detected by fluoroscopy. The correlation between percent of bolus retained in the esophagus detected by fluoroscopy and percent of bolus retention ( EII 2/ EII 1) after swallows with EIT method was r = 0.96 ( p &lt; 0.001) in supine and r = 0.69 ( p &lt; 0.001) in upright position. Conclusions &amp; Inferences The EII ratio ( EII 2/ EII 1) is a surrogate for the fraction of retained bolus after a swallow and this metric may be useful in better defining esophageal function.

Parameters for quantifying bolus retention with high‐resolution impedance manometry