Impedance characteristics of esophageal motor function in achalasia

Abstract

Detailed data on patterns of esophageal bolus transport in patients with achalasia are still lacking. To study these we applied the novel technique of multichannel intraluminal impedance measurements. Ten patients with achalasia were studied using a 16 channel system. Liquid and semisolid boluses of 10 mL were applied with the patients in a supine position. Patterns of bolus transport were determined and analyzed as compared to results obtained from 20 healthy subjects. The healthy subjects featured a unique typical primary peristalsis pattern independent of bolus viscosity. In contrast, achalasia patients demonstrated different impedance characteristics, including: (i) significantly lower baseline esophageal impedance during the resting state as compared with healthy volunteers (999 omega +/- 108 versus 2749 omega +/- 113); (ii) failed bolus transport through the esophagus in all cases; (iii) impedance evidence of luminal content regurgitation in 35% of the swallows (iv) impedance evidence of pathological air movement within the proximal esophagus during deglutition in 38% of the swallows, so called air trapping. Thus, impedance characteristics of achalasia have been defined and can be attributed to known symptoms of achalasia. They can be used as basic findings for further classification of pathological bolus transports in other esophageal motility disorders.

Manometry data support a novel concept of the lower esophageal sphincter system

“…5 Impedance manometry tracing of a patient with pronounced chalasia in its late stages. The propulsion of the food bolus occurs in a delayed and variable manner, partly with evidence of regurgitation [20]. In the entire esophagus, coordinated propulsive transport is absent.…”

“…The food bolus fails to be transported by coordinated propulsion since the esophageal motility is diminished. The stretch sphincter segment does not open properly (frequency around 4% of patients with GERD [11, 13, 16]) manometry measurements obtained from patients suffering from this disorder [20].…”

Review article: intra‐oesophageal impedance monitoring for the assessment of bolus transit and gastro‐oesophageal reflux

“…Normal values for combined impedance monitoring and manometry (solid-state catheter) have been reported by three groups. 13,16,17 Tutuian et al 13 proposed normal values for impedance parameters for liquid and viscous swallows based on a multicentre study including 43 healthy American subjects. More than 93% of individuals with manometrically normal studies were found to have at least 80% swallows with complete liquid or at least 70% swallows with complete viscous bolus transit.…”

“…Similar bolus transit parameters were described in a study including 25 healthy German subjects. 16 Normal values of baseline impedance values and deglutitive impedance gradient during saline and semisolid (yogurt) bolus transit were also provided. On the basis of a study in 18 HV, Chen and Yi 17 reported that Chinese subjects with 70% or more complete bolus transit for either liquid or viscous are considered as having normal transit.…”

“…Impedance characteristics of oesophageal motor function in achalasia were investigated in 10 patients with achalasia as compared with healthy subjects. 23 The following impedance patterns in achalasia patients were described: low oesophageal baseline impedance; failed bolus transport; regurgitation of luminal contents during swallowing and pathological air accumulation within the proximal oesophagus (air trapping) during deglutition.…”