Search

The esophagogastric junction (EGJ) is a complex barrier between the thoracic and abdominal luminal gut compartments, comprised primarily of the lower esophageal sphincter (LES) and crural diaphragm. Although closed at rest, the EGJ relaxes to allow antegrade bolus transit and retrograde venting of air. Abnormal relaxation is the hallmark of achalasia spectrum disorders, while increased frequency of transient lower esophageal sphincter relaxations and/or EGJ disruption are seen in gastroesophageal reflux disease. High resolution manometry (HRM) is the modern day gold standard for assessment of EGJ morphology and function, with better performance characteristics compared with endoscopy and barium esophagography. Conventional LES metrics defining EGJ function include resting LES pressure as well as postswallow residual pressures. Newer HRM-based metrics include EGJ contractile integral, which measures static barrier function at rest, and EGJ morphology, which characterizes the relationship between LES and crural diaphragm. Provocative maneuvers assess dynamic EGJ function during physiological or pharmacologic stress. The most useful of these maneuvers, the rapid drink challenge, assesses for latent obstruction, while multiple rapid swallows evaluate adequacy of deglutitive inhibition. Amyl nitrate and cholecystokinin administration can segregate motor from structural obstruction. Newer provocative tests (straight leg raise maneuver, abdominal compression) and novel diagnostic tools (functional lumen imaging probe) complement HRM evaluation of the EGJ. Although current HRM metrics and maneuvers show promise in identifying clinically relevant EGJ abnormalities, future investigations evaluating management outcomes will improve segregation of normal from abnormal EGJ morphology and function.

INTRODUCTION Normal response to multiple rapid swallows (MRS) during high-resolution esophageal manometry is deglutitive inhibition; opioids may interfere with this. The aim of this study was to evaluate the response to MRS in patients on opioids, not on opioids, and healthy controls. METHODS Response to MRS was evaluated for complete vs impaired inhibition in 72 chronic opioid users, 100 patients not on opioids, and 24 healthy controls. RESULTS Impaired deglutitive inhibition was significantly more frequent in chronic opioid users compared with patients not on opioids and healthy controls (54% vs 14% vs 0%; P < 0.0001). DISCUSSION Impaired deglutitive inhibition during MRS is frequent in opioid users, supporting that opioids interfere with esophageal inhibitory signals.

BACKGROUND The timed water swallow test (TWST) is a test of sequential swallowing where a measured volume is ingested as quickly as comfortably possible. We undertook a study of the biomechanics underpinning the TWST in healthy young and older participants. METHODS Thirty healthy volunteers underwent high-resolution impedance manometry (MMS; Unisensor, 2.7 mm diameter, 32 pressure sensors, 16 impedance segments). Participants were asked to drink 150 mL, 0.9% normal saline solution rapidly. Swallowing biomechanics and bolus flow characteristics were assessed using pressure-flow analysis and compared using t test and Fisher's exact test with significance as P

Although dysphagia for solids is a common complaint, the motor response to eating is not routinely studied during diagnostic manometry. Esophageal motility was examined in 47 patients with a history of dysphagia and 34 patients without dysphagia. In 22 of those with dysphagia, the symptoms were reproduced in the laboratory when the patients ate bread. These patients had a higher swallow frequency, reduced peristaltic swallow rate, and an increased rate of synchronous contractions compared to patients without dysphagia. In 22 of 53 separate episodes of dysphagia, a mixed pattern of esophageal motility was seen with peristaltic synchronous and nonconducted swallows (although peristaltic swallows were

The effect of closely spaced swallows to decrease peristalsis (‘deglutitive inhibition’) is believed to be due to both central inhibitory impulses and smooth muscle refractoriness. Ten volunteers (three females, age 26–65) were given both four pairs and two series of four swallows at 5-, 10-, 15-s intervals and control swallows at 30-s intervals. Oesophageal function was assessed using combined multichannel intraluminal impedance and oesophageal manometry (MII–OM). Swallows were considered manometrical effective if distal oesophageal pressures ≥30 mmHg. Complete bolus transit was defined as bolus exiting from all three distal impedance segments. During swallowing at 5-s intervals the majority of initial swallows were ineffective with incomplete bolus transit while the last swallow in both series and pairs was manometrically effective with complete bolus transit. During swallowing at 10–15-s intervals the number of manometric ineffective swallows and swallows with incomplete bolus transit progressively increased with the number of swallows. The functional information obtained by MII–OM indicates pooling of liquid in the distal oesophagus that is cleared by the last swallow determined by, previously reported, neural inhibition occurring during swallowing spaced 5 s apart whereas incomplete bolus transit is related to manometrically ineffective swallows resulting from muscle refractoriness occurring during swallowing at 10–15-s intervals.

Deglutitive inhibition attenuates ongoing esophageal contractions if swallows are separated by short time intervals. This study aimed to determine whether esophageal shortening, mediated by longitudinal muscle, was similarly affected. Eight healthy subjects with two distal esophageal segments demarcated by mucosal clips and manometric recording sites positioned within those segments underwent concurrent manometry and fluoroscopy. Peristaltic amplitude and change in distal segment lengths were quantified during single swallows, paired swallows separated by progressively prolonged intervals, and a series of rapid repetitive swallows. During grouped swallows, deglutitive inhibition with complete attenuation of both the manometric contraction and segment shortening was evident with short-interval swallows and rapid-sequence swallows. No inhibition of either was evident with long-interval pairs. With intermediate interswallow intervals, the occurrence and degree of deglutitive inhibition between peristaltic amplitude and segment shortening were closely correlated. Deglutitive inhibition affects both the longitudinal and circular muscle layers of the esophageal wall, and the occurrence of inhibition evident in one layer is strongly correlated with the other.

Animal studies have shown that primary esophageal peristalsis is preceded by a wave of inhibition spreading rapidly down the esophagus and lasting longer in more distal segments. In humans, its presence in the esophageal body cannot be demonstrated manometrically because of the absence of tone. To study deglutitive inhibition in humans, an artificial high-pressure zone was created by inflating an intraesophageal balloon to a critical level. The pressure changes at the interface between the balloon and the esophageal wall at various levels along the esophagus were measured. In this artificial high-pressure zone, deglutition induced a relaxation beginning simultaneously at various levels of the esophagus but lasting progressively longer in progressively more distal segments. Latency from onset of deglutition to onset of relaxation at 13 cm and 8 cm above the lower esophageal sphincter and at the lower esophageal sphincter was 0.06 +/- 0.19 seconds, 0.10 +/- 0.31 seconds, and 0.89 +/- 0.53 seconds, respectively; latency to contraction was 4.45 +/- 0.54 seconds, 6.04 +/- 0.79 seconds, and 9.14 +/- 1.04 seconds, respectively. This is the first direct evidence that deglutition produces in the human esophagus a wave of inhibition that precedes the primary peristaltic contraction.

A 56-year-old woman presented to our outpatient clinic because she had been having swallowing difficulty of solid food and liquid for the past month. Intense psychiatric stress and eating quickly provoked dysphagia, but exercise relieved the symptoms. The physical examination was unremarkable, and there were no abnormal findings on esophagogastroduodenoscopy. High-resolution manometry revealed an elevated mean integrated relaxation pressure (IRP) of 15.5 mmHg. Additionally, a simultaneous contraction was observed in 6 out of 10 swallows (Fig. 1). There were no abnormalities noted on a multiple swallow test (Fig. 2). Figure 1 High-resolution manometry (HRM) spatio-temporal plots. (A) HRM revealed elevated integrated relaxation pressure (15.9 mmHg) with increased contractile front velocity (9.8 cm/sec). (B) HRM also showed increased integrated relaxation pressure (17.5 mmHg) ... Figure 2 Normal peristalsis with deglutitive inhibition was observed on the multiple swallow test. According to the Chicago classification published in 2008, it was impossible to define the combination of these 2 findings with a single term.1 Because of the elevated mean IRP, this presentation was initially classified as impaired esophagogastric junction (EGJ) relaxation. However, there was no category consistent with both the simultaneous contraction and elevated contractile front velocity in impaired EGJ relaxation. Aside from the elevated mean IRP, this presentation was compatible with distal esophageal spasm with a contractile front velocity > 8 cm/sec in 20% of swallows. Since esophageal spasm occasionally accompanies impaired EGJ relaxation, we diagnosed the patient as distal esophageal spasm with impaired EGJ relaxation.2 However, the revised Chicago classification published in 2011 classifies this presentation as variant achalasia.3 This new classification enabled us to categorize our findings as EGJ outflow obstruction due to elevated IRP and some instances of intact peristalsis. Thereafter, we have been able to diagnose this presentation as variant achalasia more specifically after ruling out the mechanical obstruction and hypercontractility.3 Our case exhibited characteristic findings of the newly proposed category in the 2011 Chicago classification, which addresses the findings not classifiable by the 2008 Chicago classification system.