Multiple rapid swallowing in idiopathic achalasia: evidence for patients’ heterogeneity*

Abstract

In order to evaluate the function of inhibitory neural pathways in achalasia, we compared the response of the oesophageal body and lower oesophageal sphincter (LOS) to single swallows (SS) and multiple rapid swallowing (MRS) in 20 consecutive patients with untreated idiopathic achalasia (10 men, aged 23-81 years) and in 20 control patients without dysphagia (nine men, aged 31-73 years), using sleeve manometry; 277 SS and 85 MRS were analysed. In the control group, MRS inhibited motor activity in the oesophageal body and induced a slightly lower (P < 0.05) nadir LOS pressure compared with SS. In the achalasia patients, MRS induced a variable response: eight patients had simultaneous motor activity during all MRS although onset was delayed compared with SS [median (interquartile range), 3.5 s (1.7-6.1) vs 1.4 s (0.8-3.9); P < 0.05], whereas eight patients showed motor inhibition which occurred during all MRS in four of them, and the remaining four had no motor activity both after SS and during MRS. Overall MRS did not decrease nadir LOS pressure compared with SS [12 mmHg (5-20) vs 16 mmHg (7-22); P > 0.1]; however, it induced complete LOS relaxation in three of the patients. MRS gives further evidence of functional heterogeneity among achalasia patients.

Usefulness of low- and high-volume multiple rapid swallowing during high-resolution manometry

“…In the symptomatic patients, in whom 4s IRP was more variable after SS and >15 mmHg in two, MRS decreased 4s IRP presumably as a result of greater stimulation of the inhibitory neural pathways, as suggested by previously published traditional manometry data [5]. In the achalasia patients, 4s IRP was higher than in healthy subjects and did not change after MRS, most likely because of severe damage to the inhibitory neural pathways.…”

“…Each test started with eight 5 mL single swallows (SS) of water at intervals of 20-30 s, followed by two 10 mL MRS as follows: swallows of 2 mL of water were administered through a syringe at intervals of 2-3 s, while the physician indicated the rhythm of swallowing [5]. Finally, one multiple rapid swallowing of 200 mL of water within 30 s was administered using a straw [8].…”

“…Various tests have been proposed as a means of further characterising patients with oesophageal symptoms and detecting motor abnormalities in those with normal oesophageal manometry findings, including low (10 mL) or high volume (200 mL) multiple rapid swallowing (MRS) [5][6][7][8] and the ingestion of a solid bolus [8][9][10].…”

Deglutitive Inhibition, Latency Between Swallow and Esophageal Contractions and Primary Esophageal Motor Disorders

“…3). A normal response to multiple rapid swallowing requires on the one hand indemnity of inhibitory and excitatory mechanisms and on the other hand, esophageal muscle indemnity able to respond to a strong stimulation at the end of the MRS. As expected, multiple rapid swallowing induced an abnormal response in patients with achalasia 63. In contrast, symptomatic patients (dysphagia, chest pain or heartburn) with normal standard manometry showed preserved inhibition during MRS with a more significant abnormality in the post-MRS after contractions 64…”

Heterogeneity of Lower Esophageal Sphincter Function in Children With Achalasia

“…Katz et al (9), in a series of 23 patients with achalasia, noted that 7 of 23 (30%) patients had normal mean LES relaxation. Manometric LES heterogeneous response has also been demonstrated by studying the response to deglutitive inhibition in patients with achalasia (22). Also, recent data obtained from studies using high-resolution manometry (HRM) have also suggested that there is heterogeneity in the type of manometric abnormalities seen in adults with achalasia (17,23).…”