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.

In patients with mild GORD concurrent impedancometry and manometry is sufficiently sensitive for the detection of minor oesophageal dysmotility. Several pathological features have been characterized including delayed bolus transport, impaired propulsive volume clearance, pathological transport patterns and pathological reflux patterns.

The most important etiologies of achalasia are idiopathic and related to Chagas' disease. The lower esophageal sphincter pressure (LESP) in idiopathic achalasia (Id Ach) is higher compared with a healthy group, but there are different reports in Chagasic achalasia (Ch Ach). We compared the LESP of patients with both forms of achalasia and a control group. The LESP of 213 achalasia patients without previous treatment and 32 healthy volunteers were assessed. In 126 patients, the etiology could be demonstrated using serologic tests (Id Ach, 94 and Ch Ach, 32). The LESP of 213 patients was 31.86+/-14.18 mmHg and in the control group was 17.92+/-7.03 mmHg (P < 0.0001). The LESP in Id Ach and Ch Ach was 33.28+/-13.63 mmHg and 23.5+/-12.09 mmHg (P < 0.0001), respectively. Only the Id Ach group achieved statistical difference in relation to the control group (P < 0.0001). In conclusion, the LESP of Id Ach patients was higher than in Ch Ach patients and the control group, but there was no LESP difference between the Ch Ach and control groups.

Impedance parameters of normal oesophageal motor function have been characterized. Impedancometry and manometry provide different but complementary data about oesophageal motor function. Concurrent impedancometry and manometry allows detailed monitoring of oesophageal motility and bolus transit, which may open new perspectives for comprehensive oesophageal motility testing.