Apple sauce improves detection of esophageal motor dysfunction during high-resolution manometry evaluation of dysphagia

BACKGROUND

Esophageal manometry utilizes water swallows to evaluate esophageal motor abnormalities in patients with dysphagia, chest pain, or reflux symptoms. Although manometry is the gold standard for evaluation of these symptoms, patients with dysphagia often have normal results in manometry studies.

AIM

The objective of this work was to test the hypothesis that challenging the esophagus with viscous apple sauce boluses uncovers motor abnormalities in patients with dysphagia not seen when using water swallows.

METHODS

High-resolution esophageal manometry was performed using ten water swallows followed by ten apple sauce swallows in consecutive subjects presenting with dysphagia. Subjects with grossly abnormal water swallow evaluations were excluded. Each swallow was categorized as normal, hypotensive (distal isobaric contour plots of < 30 mmHg over >5 cm), or simultaneous (distal esophageal velocity ≥ 8.0 cm/s). Ineffective esophageal motility (IEM) was defined as ≥ 30% hypotensive swallows, and pressurization was defined as ≥ 20% simultaneous pressure waves.

RESULTS

Data from 41 subjects was evaluated. Overall, 96.3% of water swallows were normal, 2.9% hypotensive, and 0.7% simultaneous. Only 70.3% of viscous swallows were normal; 16.7% were hypotensive and 13.0% were simultaneous (P < 0.001 all groups). Seven (17.1%) met criteria for IEM, and pressurization with viscous swallows was observed for nine (22.0%). Fourteen subjects (34.1%) had abnormal results from viscous studies. The presence of any abnormal water swallows was predictive of abnormal viscous swallows (OR = 9.00, CI = 2.15-80.0), although the presence of hypotensive or simultaneous water swallows was not associated with IEM (OR = 0.63, CI = 0.16-2.17) or pressurization (OR = 7.00, CI = 0.90-315.4) with viscous apple sauce.

CONCLUSIONS

Apple sauce challenge increased identification of classifiable motor disorders in patients with dysphagia and may be preferred to alternative bolus materials.

Has high-resolution manometry changed the approach to esophageal motility disorders?

PURPOSE OF REVIEW

High-resolution manometry (HRM) coupled with high-resolution esophageal topography plots (HREPT) has dramatically changed the paradigm of manometric studies. The purpose of the current review is to discuss the salient advantages of HRM that are likely to change the clinical practice of manometry.

RECENT FINDINGS

Recent studies evaluating HRM suggest a significant improvement in the sensitivity for the diagnosis of achalasia when compared with conventional manometry. By reproducibly subtyping achalasia into classic achalasia, achalasia with pressurization, or spastic achalasia with differential responses to treatment, HRM has potential to predict clinical outcomes. Preliminary observations with HRM suggest that much of what was labeled distal esophageal spasm is in fact achalasia with esophageal compression and pseudorelaxation, or spastic achalasia. HRM is capable of selectively analyzing discrete esophagogastric junction contributors (lower esophageal sphincter and crural diaphragm) during deglutitive relaxation to clearly identify the site of abnormally high outflow resistance. HRM has improved the recognition of a clinically heterogeneous entity called functional obstruction with potential for directed therapy.

SUMMARY

Improved, accurate and reproducible recognition of manometric diagnoses by HRM will allow the clinician to confidently diagnose esophageal disorders such as achalasia, direct therapy and predict outcomes.

Upper esophageal sphincter during transient lower esophageal sphincter relaxation: effects of reflux content and posture

Although some studies show that the upper esophageal sphincter (UES) contracts during transient lower esophageal sphincter relaxation (TLESR), others show that it relaxes. We hypothesized that the posture of the subject and constituents of gastroesophageal reflux (GER) may determine the type of UES response during the TLESR. High-resolution manometry and esophageal pH/impedance recording were performed in 10 healthy volunteers in the right recumbent (1 h) and upright (1 h) positions following the ingestion of a 1,000-Kcal meal. The UES pressure response during TLESR and constituents of GER (liquid, air, and pH) were determined. 109 TLESRs (58 upright and 51 recumbent) were analyzed. The majority of TLESRs were associated with GER (91% upright and 88% recumbent) events. UES relaxation was the predominant response during upright position (81% of TLESRs), and it was characteristically associated with presence of air in the reflux (92%). On the other hand, UES contraction was the predominant response during recumbent position (82% of TLESRs), and it was mainly associated with liquid reflux (71%). The rate of esophageal pressure increase (dP/dt) during the GER, but not the pH, had major influence on the type of UES response during TLESR. The dP/dt during air reflux (127 +/- 39 mmHg/s) was significantly higher than liquid reflux (31 +/- 6 mmHg/s, P < 0.0001). We concluded that the nature of UES response during TLESR, relaxation or contraction, is related to the posture and the constituents of GER. We propose that the rapid rate of esophageal pressure increase associated with air reflux determines the UES relaxation response to GER.

Transient lower oesophageal sphincter relaxation in achalasia: everything but LOS relaxation

In conducting clinical high-resolution oesophageal pressure topography (HROPT) studies we observed that after subjects sat upright between series of supine and upright test swallows, they frequently had a transient lower oesophageal sphincter relaxation (TLOSR). When achalasia patients were studied in the same protocol, they exhibited a similar HROPT event leading to the hypothesis that achalasics had incomplete TLOSRs. We reviewed clinical HROPT studies of 94 consecutive non-achalasics and 25 achalasics. Studies were analyzed for a TLOSR-like event during the study and, when observed, that TLOSR-like event was characterized for the degree and duration of distal oesophageal shortening, the degree of LOS relaxation, associated crural diaphragm (CD) inhibition, oesophageal pressurization and upper oesophageal sphincter (UOS) relaxation. About 64/94 (68%) non-achalasics and 15/24 (63%) of achalasics had a pressure topography event after the posture change characterized by a prolonged period of distal oesophageal shortening and/or LOS relaxation. Events among the non-achalasics and achalasics were similar in terms of magnitude and duration of shortening and all were associated with CD inhibition. Similar proportions had associated non-deglutitive UOS relaxations. The only consistent differences were the absence of associated LOS relaxation and the absence of HROPT evidence of reflux among the achalasics leading us to conclude that their events were incomplete TLOSRs. Achalasic patients exhibit a selective defect in the TLOSR response suggesting preservation of all sensory, central and efferent aspects of the requisite neural substrate with the notable exception of LOS relaxation, a function of inhibitory (nitrergic) myenteric plexus neurons.

High-resolution manometry in clinical practice: utilizing pressure topography to classify oesophageal motility abnormalities

High-resolution manometry capable of pressure monitoring from the pharynx to the stomach together with pressure topography plotting represents an unquestionable evolution in oesophageal manometry. However, with this advanced technology come challenges and one of those is devising the optimal scheme to apply high-resolution oesophageal pressure topography (HROPT) to the clinical evaluation of patients. The first iteration of the Chicago classification was based on a systematic analysis of motility patterns in 75 control subjects and 400 consecutive patients. This review summarizes the analysis process as it has evolved. Individual swallows are analysed in a stepwise fashion for the morphology of the oesophagogastric junction (OGJ), the extent of OGJ relaxation, the propagation velocity of peristalsis, the vigour of the peristaltic contraction, and abnormalities of intrabolus pressure utilizing metrics that have now been customized to HROPT. These results are then synthesized into a comprehensive diagnosis that, although based on conventional manometry criteria, is also customized to HROPT measures. The resultant classification objectifies the identification of three unique subtypes of achalasia. Additionally, it provides enhanced detail in the description of distal oesophageal spasm, nutcracker oesophagus subtypes, and OGJ obstruction. It is our expectation that modification of this classification scheme will continue to occur and this should further clarify the utility of pressure topography plotting in assessing oesophageal motility disorders.

Oesophageal peristaltic transition zone defects: real but few and far between

This study analysed the association between oesophageal transition zone (TZ) defects [characterized by a delay and/or spatial gap between the terminus of the proximal oesophageal (striated muscle) contraction and the initiation of the distal oesophageal (smooth muscle) contraction] and dysphagia in a large patient cohort. Four hundred consecutive patients (178 with dysphagia) and 75 controls were studied with 36-channel high-resolution manometry (HRM). The resultant pressure topography plots were first analysed for impaired oesophagogastric junction (OGJ) relaxation, distal segment contractile abnormalities, and proximal contractile abnormalities using normal values from the 75 controls. If these aspects of oesophageal motility were deemed normal, the TZ was characterized by length and duration between the proximal and distal contractions using a 20 mmHg isobaric contour to establish the segment boundaries. Patients were then classified according to whether or not they exhibited TZ defects (spatial separation or delay) and the occurrence of unexplained dysphagia. Of the 400 patients, 267 were suitable for TZ analysis and of these 55 had a spatial or temporal TZ measurement exceeding the 95th percentile of the controls (2 cm, 1 s). Exactly 34.6% of the patients (n = 19) with spatial and/or temporal TZ defects had unexplained dysphagia, which was significantly more than seen with normal TZ dimensions (19.8%). Although far less common than distal peristaltic or OGJ abnormailites, TZ defects may be related to dysphagia in a minority of patients (<4% in this series) and should be considered a distinct oesophageal motility disorder.