Boudewijn F. Kessing

Esophageal acid exposure decreases intraluminal baseline impedance levels.

OBJECTIVES:Intraluminal baseline impedance levels are determined by the conductivity of the esophageal wall and can be decreased in gastroesophageal reflux disease (GERD) patients. The aim of this study was to investigate the baseline impedance in GERD patients, on and off proton pump inhibitor (PPI), and in healthy controls.METHODS:Ambulatory 24-h pH–impedance monitoring was performed in (i) 24 GERD patients with and 24 without pathological esophageal acid exposure as well as in 10 healthy controls and in (ii) 20 patients with refractory GERD symptoms despite PPI, once on PPI and once off PPI. Baseline impedance levels in the most distal and the most proximal impedance channels were assessed.RESULTS:Median (interquartile range) distal baseline impedance in patients with physiological (2,090 (1,537–2,547) Ω) and pathological (781 (612–1,137) Ω) acid exposure was lower than in controls (2,827 (2,127–3,270) Ω, P<0.05 and P<0.001). A negative correlation between 24-h acid exposure time and baseline impedance was observed (r=−0.7, P<0.001). In patients measured off and on PPI, median distal baseline impedance off PPI was significantly lower than on PPI (886 (716–1,354) vs. 1,372 (961–1,955) Ω, P<0.05) and distal baseline impedance in these groups was significantly lower than in healthy controls (P<0.05 and P<0.001). Proximal baseline impedance did not differ significantly between the patients off PPI and on PPI (1,793 (1,384–2,489) vs. 1,893 (1,610–2,561) Ω); however, baseline impedance values in both measurements were significantly lower than in healthy controls (3,648 (2,815–3,932) Ω, both P<0.001).CONCLUSIONS:These findings suggest that baseline impedance is related to esophageal acid exposure and could be a marker of reflux-induced changes to the esophageal mucosa.

Normal values for solid-state esophageal high-resolution manometry in a European population; an overview of all current metrics

Esophageal high‐resolution manometry (HRM) allows accurate evaluation of esophageal motility. Normal values for HRM were established in the United States and several new parameters were introduced since. We aimed to provide a complete set of normal values for HRM obtained in a European population, including all current metrics used to describe the function of the upper esophageal sphincter (UES), the esophageal body, and the esophagogastric junction (EGJ).

Objective Manometric Criteria for the Rumination Syndrome

OBJECTIVES:The rumination syndrome is a behavioral disorder resulting in recurrent regurgitation of undigested food. The diagnosis of this syndrome is currently based on clinical features. We aimed to determine criteria for the rumination syndrome based on physiological measurements.METHODS:We studied patients with clinically confirmed rumination syndrome and gastroesophageal reflux disease (GERD) patients with predominant symptoms of regurgitation. All patients underwent combined high-resolution manometry and pH-impedance measurement after a standardized meal. All reflux events extending to the proximal esophagus were analyzed. Furthermore, ambulatory measurements were performed in the majority of patients.RESULTS:In the rumination group, the amplitude of the abdominal pressure increase during proximal reflux events and the esophageal pressure peaks were significantly higher compared with GERD patients. None of the GERD patients exhibited abdominal pressure peaks >30 mm Hg, whereas in the rumination patients 70% of the pressure peaks had an amplitude >30 mm Hg. Abdominal pressure patterns were also observed during ambulatory pH impedance–pressure monitoring in the rumination patients. pH-impedance monitoring alone could not differentiate between GERD and rumination, however, a higher percentage of reflux events reached the proximal esophagus in the rumination patients. Notably, three different mechanisms of rumination were observed: (i) primary rumination, in which the abdominal pressure increase preceded the retrograde flow, (ii) secondary rumination, consisting of an increase in abdominal pressure following the onset of a reflux event and (iii) supragastric belch-associated rumination, consisting of a supragastric belch immediately followed by a rumination event.CONCLUSIONS:The diagnosis of the rumination syndrome can be made when reflux events extending to the proximal esophagus that are closely associated with an abdominal pressure increase >30 mm Hg and an esophageal pressure increase are observed during combined pressure-impedance monitoring.

Erroneous Diagnosis of Gastroesophageal Reflux Disease in Achalasia

BACKGROUND & AIMS Most experienced gastroenterologists have seen one or several cases of achalasia patients who have been erroneously diagnosed with gastroesophageal reflux disease (GERD) or even underwent antireflux surgery. We aim to describe the current knowledge about the diagnostic features of achalasia and their overlap with GERD. Furthermore, we present 3 cases in which achalasia was mistaken for GERD. METHODS Search of the literature published in English using the PubMed database and relevant abstracts presented at international conventions. RESULTS Typical features of GERD such as heartburn, retrosternal pain, esophagitis, and pathologic acid exposure can be observed in achalasia patients. Diagnostic tests such as endoscopy and radiography lack sensitivity and specificity for achalasia. Current diagnostic guidelines for antireflux surgery do not stipulate that achalasia should be ruled out preoperatively. CONCLUSIONS Clinical presentation as well as the diagnostic work-up of achalasia patients can show overlap with GERD. Mistaking achalasia for GERD can be avoided by esophageal manometry and this should therefore be performed in all patients undergoing surgical fundoplication.

Clinical Applications of Esophageal Impedance Monitoring and High-Resolution Manometry

Esophageal impedance monitoring and high-resolution manometry (HRM) are useful tools in the diagnostic work-up of patients with upper gastrointestinal complaints. Impedance monitoring increases the diagnostic yield for gastroesophageal reflux disease in adults and children and has become the gold standard in the diagnostic work-up of reflux symptoms. Its role in the work-up for belching disorders and rumination seems promising. HRM is superior to other diagnostic tools for the evaluation of achalasia and contributes to a more specific classification of esophageal disorders in patients with non-obstructive dysphagia. The role of HRM in patients with dysphagia after laparoscopic placement of an adjustable gastric band seems promising. Future studies will further determine the clinical implications of the new insights which have been acquired with these techniques. This review aims to describe the clinical applications of impedance monitoring and HRM.

The Pathophysiology, Diagnosis and Treatment of Excessive Belching Symptoms

Excessive belching is a commonly observed complaint in clinical practice that can occur not only as an isolated symptom but also as a concomitant symptom in patients with gastroesophageal reflux disease (GERD) or functional dyspepsia. Impedance monitoring has revealed that there are two mechanisms through which belching can occur: the gastric belch and the supragastric belch. The gastric belch is the result of a vagally mediated reflex leading to relaxation of the lower esophageal sphincter and venting of gastric air. The supragastric belch is a behavioral peculiarity. During this type of belch, pharyngeal air is sucked or injected into the esophagus, after which it is immediately expulsed before it has reached the stomach. Patients who belch excessively invariably exhibit an increased incidence of supragastric, not of gastric belches. Moreover, supragastric belches can elicit regurgitation episodes in patients with the rumination syndrome and sometimes appear to induce reflux episodes as well. Behavioral therapy has been proven to decrease belching complaints in patients with isolated excessive belching, but its effect is unknown in frequently belching patients with GERD, functional dyspepsia or rumination.

Water-perfused esophageal high-resolution manometry: normal values and validation

Water-perfused high-resolution manometry (HRM) catheters with 36 unidirectional pressure channels have recently been developed, but normal values are not yet available. Furthermore, the technique has not been validated and compared with solid-state HRM. We therefore aimed to develop normal values for water-perfused HRM and to assess the level of agreement between water-perfused HRM and solid-state HRM. We included 50 healthy volunteers (mean age 35 yr, range 21-64 yr; 15 women, 35 men). Water-perfused HRM and solid-state HRM were performed in a randomized order. Normal values were calculated as 5th and 95th percentile ranges, and agreement between the two systems was assessed with intraclass correlation coefficient (ICC) statistics. The 5th-95th percentile range was 3.0-6.6 cm/s for contractile front velocity (CFV), 141.6-3,674 mmHg·s·cm for distal contractile integral (DCI), 6.2-8.7 s for distal contraction latency (DL), and 1.0-18.8 mmHg for integrated relaxation pressure (IRP 4s). Mean (SD) and ICC for water-perfused HRM and solid-state HRM were 4.4 (1.1) vs. 3.9 (0.9) cm/s, ICC: 0.49 for CFV; 1,189 (1,023) vs. 1,092 (1,019) mmHg·s·cm, ICC: 0.90 for DCI; 7.4 (0.8) vs. 6.9 (0.9) s, ICC: 0.50 for DL; and 8.1 (4.8) vs. 7.9 (5.1), ICC: 0.39 for IRP 4s. The normal values for this water-perfused HRM system are only slightly different from previously published values with solid-state HRM, and moderate to good agreement was observed between the two systems, with only small differences in outcome measures.

Oesophageal baseline impedance values are decreased in patients with eosinophilic oesophagitis

Background Gastro-oesophageal reflux has been suggested to play a role in eosinophilic oesophagitis (EoO). Oesophageal acid exposure decreases baseline intraluminal impedance, a marker of mucosal integrity, in patients with gastro-oesophageal reflux disease (GORD). Objectives The aim of this study was to assess oesophageal baseline impedance levels in EoO patients and to investigate their relationship with oesophageal acid exposure. Methods Ambulatory 24-h pH-impedance monitoring was performed in 11 EoO patients and in 11 healthy controls with matched oesophageal acid exposure. We assessed baseline impedance levels in the distal, mid-, and proximal oesophageal impedance channels. Results Baseline impedance levels in EoO patients were markedly lower compared to controls in the distal oesophagus (median (interquartile range): 988 (757–1978) vs. 2259 (1767–2896) Ω, p = 0.015), mid-oesophagus (1420 (836–2164) vs. 2614 (2374–3879) Ω, p = 0.003), and proximal oesophagus (1856 (1006–2625) vs. 2868 (2397–3439) Ω, p = 0.005). Whereas baseline impedance decreased from proximal to distal in healthy subjects (p = 0.037), no such gradient was seen in EoO patients (p = 0.123). Conclusions Throughout the oesophagus, baseline impedance values are decreased in EoO patients, indicating impaired mucosal integrity. Our findings suggest that factors other than acid reflux are the cause of low baseline impedance in EoO.

Esophagogastric junction distensibility identifies achalasia subgroup with manometrically normal esophagogastric junction relaxation.

Manometric criteria to diagnose achalasia are absent peristalsis and incomplete relaxation of the esophagogastric junction (EGJ), determined by an integrated relaxation pressure (IRP) >15 mm Hg. However, EGJ relaxation seems normal in a subgroup of patients with typical symptoms of achalasia, no endoscopic abnormalities, stasis on timed barium esophagogram (TBE), and absent peristalsis on high‐resolution manometry (HRM). The aim of our study was to further characterize these patients by measuring EGJ distensibility and assessing the effect of achalasia treatment.

Current diagnosis and management of the rumination syndrome.

The rumination syndrome is a behavioral condition characterized by postprandial regurgitation. In contrast to what many think, the disorder does not exclusively occur in mentally disabled patients or children but also in otherwise healthy adults. As symptoms of postprandial regurgitation are often mistaken for gastroesophageal reflux disease or vomiting, the rumination syndrome is an underappreciated condition. Rumination episodes are caused by an intragastric pressure increases which forces the gastric content into the esophagus and mouth and occurs during 3 distinct mechanisms: primary rumination, secondary rumination, and supragastric belch-associated rumination. Combined manometry-impedance can distinguish rumination from gastroesophageal reflux disease. Treatment of the rumination syndrome consists of a thorough explanation of the mechanisms underlying the rumination episodes and behavioral therapy. As behavioral therapy is a time-consuming and often expensive treatment, we propose that a clinical suspicion of the disorder is always confirmed by a manometry-impedance measurement.