Impedance detected abnormal bolus transit in patients with normal esophageal manometry. Sensitive indicator of esophageal functional abnormality?

In ineffective esophageal motility, failed swallows are more functionally relevant than weak swallows

BACKGROUND

Esophageal pressure topography (EPT) diagnosis of ineffective esophageal motility (IEM) can be non-specific with unclear clinical significance.

AIMS

To determine whether peristaltic vigor or lower esophageal sphincter (LES) integrity is associated with poor clearance and acid reflux in IEM.

METHODS

Bolus clearance on high-resolution impedance manometry (HRIM) and available reflux studies in patients with IEM were retrospectively reviewed. Bolus clearance was assessed using both line tracing and colored contour methods on HRIM. EPT parameters, bolus clearance, and acid reflux variables were explored.

KEY RESULTS

Eighty-eight patients with IEM were included. Bolus clearance occurred in 71% of all swallows, and 55.7% of patients had complete bolus transit (CBT, bolus clearance in ≥80% of swallows). Bolus clearance was impaired in swallows with distal contractile integral (DCI) <100 mmHg•cm•s compared to DCI 100-450 (0.43 vs 0.79, P < .0001). A cutoff at DCI 100 mmHg•cm•s was associated with clearance with an accuracy of 76% compared to 49% at DCI 450 (P = .0001 for both). A median DCI <100 was associated with a higher Eckardt score (9 vs 3, P = .03), and on reflux testing available in 47 patients, with abnormal acid exposure time (P = .002). Peristaltic reserve (PR) defined as (DCI of multiple rapid swallow/median DCI of wet swallows), integrated relaxation pressure, and resting lower esophageal sphincter pressure were not associated with clearance or acid exposure.

CONCLUSIONS & INFERENCES

Failed peristalsis, as defined by DCI <100 mmHg•cm•s, is associated with impaired bolus clearance and more severe dysphagia in IEM, and likely abnormal acid exposure.

Impedance as an adjunct to manometric testing to investigate symptoms of dysphagia: What it has failed to do and what it may tell us in the future

Dysphagia is a common reason for referral for investigations of oesophageal motility. Impedance measurement has now been incorporated into commercially available diagnostic manometry systems for more than a decade. This innovation, which offered the ability to record patterns of bolus transport without the need for simultaneous radiology, has for the most part failed to live up to expectations, offering few additional diagnostic insights. This review examines the potential pitfalls related to how impedance patterns are currently analysed and introduces and discusses the new concept of pressure-flow analysis integrating pressure and impedance measurements to derive new metrics linked to the pressures occurring within and around the bolus as it is being transported.

Viscous impedance is an important indicator of abnormal esophageal motility

BACKGROUND

Non-obstructive Dysphagia (NOD) is one of the most common symptoms evaluated using esophageal manometry. Although manometry is considered the gold standard, many NOD patients have normal evaluations. Esophageal function testing with combined multichannel intraluminal impedance and esophageal manometry (MII-EM) is performed using ten 5-mL swallows of a liquid and a viscous material and provides supplemental information about bolus transit. The aim of this study was to evaluate esophageal function using combined MII-EM in patients with NOD who had normal evaluations with liquid manometry.

METHODS

Multichannel intraluminal impedance and esophageal manometry was performed in consecutive patients presenting for evaluation of NOD. Patients were excluded if any abnormality was detected during liquid manometry. Viscous manometry and liquid and viscous impedance data were analyzed to detect manometric or bolus transit abnormalities. Patients referred for GERD evaluation without any swallowing complaints were used as patient controls and were subject to the same exclusion criteria as the NOD group. All swallow evaluations were performed with 10 liquid and 10 viscous swallows.

KEY RESULTS

Data from 240 patients were evaluated, 129 with NOD and 111 patient controls. In the NOD group, 9% (12/129) had abnormal liquid impedance and 29% (37/129) had abnormal viscous impedance. In the control group, 4% (4/111) had abnormal liquid impedance and 16% (18/111) had abnormal viscous impedance. Chi-square analysis showed a significant difference between the two study groups for viscous impedance (P = 0.02) but not for liquid impedance (P = 0.12).

CONCLUSIONS & INFERENCES

Our data support our belief that a normal liquid manometry with an abnormal viscous impedance analysis in a patient with NOD indicates abnormal esophageal motility. Therefore, viscous impedance should be performed on all patients during the evaluation of NOD.

High resolution impedance manometric findings in dysphagia of Huntington’s disease

Conventional manometry presents significant challenges, especially in assessment of pharyngeal swallowing, because of the asymmetry and deglutitive movements of oropharyngeal structures. It only provides information about intraluminal pressure and thus it is difficult to study functional details of esophageal motility disorders. New technology of solid high resolution impedance manometry (HRIM), with 32 pressure sensors and 6 impedance sensors, is likely to provide better assessment of pharyngeal swallowing as well as more information about esophageal motility disorders. However, the clinical usefulness of application of HRIM in patients with oropharyngeal dysphagia or esophageal dysphagia is not known. We experienced a case of Huntington’s disease presenting with both oropharyngeal and esophageal dysphagia, in which HRIM revealed the mechanism of oropharyngeal dysphagia and provided comprehensive information about esophageal dysphagia.

Comparison of bolus transit patterns identified by esophageal impedance to barium esophagram in patients with dysphagia

Bolus transit through the esophagus has not been validated by videoesophagram in patients with dysphagia and changes in impedance with abnormal barium transit have not been described in those patients. The aim of this study was to compare esophageal impedance findings with barium esophagram measurements in patients with dysphagia. The consecutive patients with dysphagia underwent conventional multichannel esophageal impedance manometry, after which a barium videoesophagram was performed simultaneously with multichannel esophageal impedance manometry using a mean of three swallows of barium. Esophageal emptying patterns shown in the esophagogram were classified by the degree of intraesophageal stasis and presence of intraesophageal reflux. Bolus transit patterns in impedance were classified as complete and incomplete transit. Sixteen patients (M : F = 8 : 8, mean age, 47 years) were enrolled. Their manometric diagnosis were normal (n= 6), ineffective esophageal motility (n= 1), diffuse esophageal spasm (DES; n= 2), and achalasia (n= 7). Sixty-three swallows were analyzed. According to impedance analysis, 21/22 swallows with normal barium emptying showed complete transit (96%) and 31/32 swallows with severe stasis showed incomplete transit (97%). Nine swallows with mild stasis showed either complete or incomplete transit patterns in impedance. Swallows with mild barium stasis and complete transit in impedance were observed in patients who had received treatment (two patients with achalasia with history of esophageal balloonplasty and a patient with DES after nifedipine administration). Impedance reflected severe stasis with retrograde barium movement and described typical bolus transit patterns in patients with achalasia and DES. In conclusion, impedance-barium esophagram concordance is high for swallows with normal esophageal emptying and for severe barium stasis in patients with dysphagia.

An audit of combined multichannel intraluminal impedance manometry in the assessment of dysphagia

BACKGROUND

Multichannel Intraluminal Impedance (MII) Monitoring is a method of examining oesophageal bolus transit without the need for radiation. In combination with oesophageal manometry it allows correlation of bolus transit with peristaltic activity. The clinical application of impedance manometry is still being refined. This audit looked to examine whether impedance manometry had advantages over standard manometry in assessment of patients with dysphagia.

METHODS

41 patients with the presenting symptom of dysphagia were assessed by combined MII and oesophageal manometry at a Wellington Hospital between February 2008 and December 2009. Each underwent manometry and MII using standardised techniques.

FINDINGS

Achalasia was diagnosed in 23 patients (56.1%), Ineffective oesophageal motility (IEM) in 5 patients (12.2%), Diffuse oesophageal Spasm (DES) in 7 patients (17.1%), and Nutcracker oesophagus in 2 patients (4.9%). 4 patients had normal manometry studies (9.8%). All patients with achalasia, IEM, and DES had abnormal bolus transit. All patients with normal manometry had abnormal bolus transit. Both patients with nutcracker oesophagus had normal bolus transit. 4 patients with achalasia had undergone previous Hellers myotomy. Two of these patients (50.0%) now had normal LES relaxation pressures, but all four still had abnormal oesophageal peristalsis and abnormal bolus transit.

INTERPRETATION

Multichannel Intraluminal Impedance manometry has advantages over standard manometry in characterising the physiological abnormalities associated with dysphagia. Patients in this study had severe defects including achalasia where bolus transit was invariably poor meaning little further information was gained. Extension of this study to include a wider group of patients with dysphagia may yield different results.