Impact of nadir lower oesophageal sphincter pressure on bolus clearance assessed by combined manometry and multi‐channel intra‐luminal impedance measurement

Abstract

This study aimed to assess the relationship between nadir lower oesophageal sphincter pressure (LOSP) and wave amplitude (WA) in oesophageal bolus clearance. Concurrent oesophageal manometry and impedance were performed in 146 subjects [41 healthy, 24 non-obstructive dysphagia (NOD) and 81 gastro-oesophageal reflux (GOR)]. Patients with achalasia and diffuse oesophageal spasm were excluded. Swallow responses were categorized by nadir LOSP. For each category of nadir LOSP, WA at the distal 2 recording sites were grouped into bins of 10 mmHg and the proportion of waves in each bin associated with a normal bolus presence time (BPT) was determined. Nadir LOSP, distal BPT, total bolus transit time and the proportion of impaired oesophageal clearance in patients with NOD were greater than those of healthy subjects and patients with GOR. Overall, responses with impaired oesophageal clearance had significantly lower WA (54 +/- 1 vs 81 +/- 1 mmHg; P < 0.0001) and higher nadir LOSP (2.7 +/- 0.4 vs 1.0 +/- 0.1 mmHg, P < 0.001). For each level of nadir LOSP, there was a direct relationship between distal WA and successful bolus clearance of both liquid and viscous boluses from the distal oesophagus. As nadir LOSP increased, the relationship between WA and bolus clearance shifted to the right and higher amplitudes were required to achieve the same effectiveness of clearance. Hypotensive responses with nadir LOSP > or = 3 mmHg were less likely to clear than those with nadir LOSP < 3 mmHg, for both liquid (7/29 vs 162/276; P < 0.001) or viscous boluses (11/46 vs 176/279; P < 0.0001). Nadir LOSP is an important determinant of bolus clearance from the distal oesophagus, particularly in patients with NOD.

Automated impedance manometry analysis as a method to assess esophageal function

“…One possible explanation of this is that metrics which characterize features of the intrabolus domain are not well integrated into the present classification system. Bolus transit and clearance can be assessed with intraluminal impedance measurement . However, on its own, impedance measurement has failed to deliver the anticipated diagnostic gain in dysphagia, possibly because failed bolus clearance in itself occurs commonly in asymptomatic individuals.…”

“…Although an improved sensitivity to detect motor dysfunctions leading to abnormal bolus flow was expected with the use of HRM, a recent study showed that HRM based metrics were also poorly predictive of bolus transit failure, suggesting that manometry as a stand‐alone technique may not be sensitive enough to elucidate esophageal motility events underlying ineffective esophageal bolus clearance and/or dysphagia. Hence, the utility of combining the esophageal motility patterning with bolus flow using intraluminal impedance measurement was proposed and extensively used as a technique to assess bolus transport throughout the esophageal lumen and across the EGJ . However, to date, the combined manometry‐impedance technique, as routinely applied, yields little in terms of further diagnostic insights in patients presenting with dysphagia.…”

“…However, to date, the combined manometry‐impedance technique, as routinely applied, yields little in terms of further diagnostic insights in patients presenting with dysphagia. This may relate to the fact that combining the two techniques so far does bring simultaneous recordings, but the analysis of manometry and impedance parameters was still done separately, with the interaction between them being limited to co‐occurrence of the metrics . Recently, the use of a novel integrated analysis method of combined HRM and impedance measurements has been assessed for abnormal bolus flow throughout the pharynx and upper esophageal sphincter and proved to be highly sensitive and specific for the detection of bolus residual and aspiration during deglutition …”

Automated impedance‐manometry analysis detects esophageal motor dysfunction in patients who have non‐obstructive dysphagia with normal manometry

“…Manometric measurements The manometric recordings were analyzed manually to determine: (i) esophageal pressure wave amplitude and velocity, (ii) peristaltic success, and (iii) basal and nadir LES pressure. The definition of normal and various abnormal esophageal motility conditions have been previously reported 3,6,13 …”

Combined impedance-manometry for the evaluation of esophageal disorders

“…Previous studies using standard impedance-manometry recordings have shown that nadir lower esophageal sphincter (LES) pressure during swallowing has an impact on the propulsive force necessary for complete bolus transit, even within the normal range for swallow-induced LES relaxation [24]. This was particularly so for patients with nonobstructive dysphagia.…”