Relationship between bolus transit and LES-relaxation studied with concurrent impedance and manometry

BACKGROUND/AIMS

Neuromuscular mechanisms regulating esophageal bolus transport are well studied. However, detailed data about the relationship between bolus transit and lower esophageal sphincter (LES)-relaxation during conventional motility testing are still lacking.

METHODOLOGY

We performed systematic studies in 25 normal subjects, employing a catheter that integrates the two techniques impedancometry and manometry in a single instrument for simultaneous recording and analysis of the relationship between bolus transit and LES relaxation after swallowing saline or yogurt.

RESULTS

195 swallows were analyzed. LES relaxation occurred frequently later than UES relaxation. The mean latency between bolus entry into the esophagus and LES relaxation was 3.6 +0.2 sec. Two types of swallow-induced LES relaxation were observed: (a) LES relaxation preceding bolus transit (46 cases or 24%) and (b) LES relaxation occurring during bolus transit (149 cases or 76%). In the later case, during 114 (76%) cases of this deglutition, the position of the bolus was very close to the LES.

CONCLUSIONS

During deglutition, LES relaxation seems to be modulated by bolus transit and occurs predominantly upon arrival of the bolus in the distal esophagus.

Impedance characteristics of esophageal motor function in achalasia

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.

Lower esophageal sphincter pressure in idiopathic achalasia and Chagas disease-related achalasia

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.

[Differential diagnosis of esophageal motor disorders based in characteristics of dysphagia]

BACKGROUND

Dysphagia is one of principal symptoms of esophageal disorders and its characterization is important for diagnosis and management of patients. Anamnesis is useful for differentiating organic and functional dysphagia, but data are lacking about dysphagia characterization among different motor disorders.

OBJECTIVES

To evaluate if it is possible the distinction among esophageal motor disorders according to their manometric diagnosis, based on dysphagia characteristics.

PATIENTS AND METHODS

Dysphagia characteristics (relation with bolus, frequency and localization) of 133 patients submitted to esophageal manometry were reviewed and analysed. All patients had barium swallow studies and/or endoscopy in order to exclude organic lesions.

RESULTS

Esophageal manometry was abnormal in 85% of the patients. Characteristics of dysphagia were compared among groups of patients with achalasia, esophageal spastic disorders, non-specific esophageal motor disorders and with normal test. The precise distinction among groups based solely on characteristics of dysphagia was not possible, however some aspects could point to one or another group. In achalasia patients, dysphagia for both solid food and liquids, constant and felt in substernal area, was more frequent in relation to every other group. Intermittent dysphagia was more frequent in patients with spastic disorders. Characteristics of dysphagia in patients with non-specific esophageal motor disorders were similar to those observed in the group with normal test, frequently referred in the neck.

CONCLUSION

Characteristics of dysphagia were ancillary to presume the diagnosis of these motor disturbances, however esophageal manometry is necessary for the correct diagnosis in patients with functional dysphagia.