The Transdiaphragmatic Pressure Gradient and the Lower Esophageal Sphincter in the Pathophysiology of Gastroesophageal Reflux Disease: an Analysis of 500 Esophageal Function Tests.

BACKGROUND: Gastroesophageal reflux disease (GERD) pathophysiology is multifactorial. Greater importance has been attributed to a defective lower esophageal sphincter (LES) in comparison to an altered transdiaphragmatic pressure gradient (TPG). This study aims to evaluate the role of the TPG and LES disfunction in GERD pathogenesis. METHODS: Five hundred consecutive esophageal function tests from patients with clinically suspected GERD were reviewed. Patients were classified according to the pH monitoring in GERD positive or GERD negative. Abdominal pressure, thoracic pressure, TPG (abdominal-thoracic pressures), LES resting pressure (mid-respiratory, expiratory, and EGJ-CI), and LES retention pressure (LES resting pressure-TPG) were determined. RESULTS: GERD was present in 296 (59%) individuals. GERD-positive patients were mostly males. LES resting pressure (by all parameters) and thoracic pressure were not different between groups. Abdominal pressure and TPG were higher in GERD-positive patients. LES retention pressure (by all parameters) was lower in GERD-positive patients. DeMeester score had a positive correlation with LES resting pressure, TPG, and LES retention pressure (by all parameters) but not with abdominal pressure and thoracic pressure. CONCLUSIONS: LES valvular competency as measured by absolute resting pressure was not reliable to predict GERD; however, it was associated with GERD severity. Relative LES pressure (LES retention pressure) predicted GERD presence and severity, but no parameter showed superiority. TPG plays an important role in the pathophysiology of GERD since it is related to GERD presence and severity; still TPG is altered mostly based on a higher abdominal pressure.

Changes in the Treatment of Primary Esophageal Motility Disorders Imposed by the New Classification for Esophageal Motility Disorders on High Resolution Manometry (Chicago Classification 4.0).

The Chicago Classification is the most used classification for primary esophageal motility disorders (PEMD). This classification was recently updated to the 4.0 version. This opinion piece focuses on the possible implications for the treatment of PMED determined by the new classification. Chicago Classification 4.0 included two new concepts for the diagnosis of achalasia: (1) type III achalasia diagnosis demands 100% absent peristalsis defined as either failed peristalsis or spasm; (2) "inconclusive diagnosis of achalasia" was added as a possibility. Both may decrease unnecessary treatment. Esophagogastric junction outflow obstruction, distal esophageal spasm, and hypercontractile esophagus were only considered clinically significant when correlated to supportive testing and relevant clinical symptoms and in the absence of gastroesophageal reflux disease. This may decrease the surge of treatment, especially peroral endoscopic myotomy, based solely on manometric diagnosis.

O papel do gradiente pressórico transdiafragmático na fisiopatologia da doença do refluxo gastroesofágico / The role of the transdiaphragmatic pressure gradient in the pathophysiology of gastroesophageal reflux disease

ABSTRACT Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract in the Western world. GERD pathophysiology is multifactorial. Different mechanisms may contribute to GERD including an increase in the transdiaphragmatic pressure gradient (TPG). The pathophysiology of GERD linked to TPG is not entirely understood. This review shows that TPG is an important contributor to GERD even when an intact esophagogastric barrier is present in the setting of obesity and pulmonary diseases.

RESUMO A doença do refluxo gastroesofágico (DRGE) é a enfermidade mais comum do trato digestivo alto no mundo ocidental. A fisiopatologia da DRGE é multifatorial. Diferentes mecanismos podem contribuir para um aumento do gradiente pressórico transdiafragmático (GPT). A fisiopatologia da DRGE associada ao GPT não é totalmente compreendida. Esta revisão enfoca que o GPT é um importante contribuinte para DRGE mesmo na presença de uma barreira gastroesofágica intacta como na obesidade e doenças pulmonares crônicas.

THE ROLE OF THE TRANSDIAPHRAGMATIC PRESSURE GRADIENT IN THE PATHOPHYSIOLOGY OF GASTROESOPHAGEAL REFLUX DISEASE.

Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract in the Western world. GERD pathophysiology is multifactorial. Different mechanisms may contribute to GERD including an increase in the transdiaphragmatic pressure gradient (TPG). The pathophysiology of GERD linked to TPG is not entirely understood. This review shows that TPG is an important contributor to GERD even when an intact esophagogastric barrier is present in the setting of obesity and pulmonary diseases.

Chronic Obstructive Pulmonary Disease Exacerbations Are Influenced by Gastroesophageal Reflux Disease.

Gastroesophageal reflux disease (GERD) is associated with different pulmonary diseases, including chronic obstructive pulmonary disease (COPD). Whether GERD is contributory to COPD severity remains unclear. This study aims to evaluate the contribution of GERD to the clinical manifestation of COPD based on ventilatory parameters and yearly clinical exacerbations. We studied 48 patients (56% females, age 66 years) with COPD. All patients underwent high-resolution manometry and esophageal pH monitoring. The patients were separated into two groups according to the presence of GERD. GERD was present in 21 (44%) patients. GERD + and GERD - groups did not differ in regard to gender, age, and body mass index. Pulmonary parameters were not different in the absence or presence of GERD. The number of yearly exacerbations was higher in patients GERD+. The severity of GERD (as measured by DeMeester score) correlated with the number of exacerbations. Our results show the following: 1) GERD does not influence pulmonary parameters and 2) GERD is associated with a higher number of annual clinical exacerbations. We believe GERD must be objectively tested in patients with COPD because the prevalence of GERD in these patients is underestimated when only symptoms are considered. GERD treatment might decrease the frequency of episodes of exacerbation.

Inhaled Beta Agonist Bronchodilator Does Not Affect Trans-diaphragmatic Pressure Gradient but Decreases Lower Esophageal Sphincter Retention Pressure in Patients with Chronic Obstructive Pulmonary Disease (COPD) and Gastroesophageal Reflux Disease (GERD).

BACKGROUND: Chronic obstructive pulmonary disease (COPD) patients have a high incidence of gastroesophageal reflux disease (GERD) whose pathophysiology seems to be linked to an increased trans-diaphragmatic pressure gradient and not to a defective esophagogastric barrier. Inhaled beta agonist bronchodilators are a common therapy used by patients with COPD. This drug knowingly not only leads to a decrease in the lower esophageal sphincter (LES) resting pressure, favoring GERD, but also may improve ventilatory parameters, therefore preventing GERD. AIMS: This study aims to evaluate the effect of inhaled beta agonist bronchodilators on the trans-diaphragmatic pressure gradient and the esophagogastric barrier. METHODS: We studied 21 patients (mean age 67 years, 57 % males) with COPD and GERD. All patients underwent high-resolution manometry and esophageal pH monitoring. Abdominal and thoracic pressure, trans-diaphragmatic pressure gradient (abdominal-thoracic pressure), and the LES retention pressure (LES basal pressure-transdiaphragmatic gradient) were measured before and 5 min after inhaling beta agonist bronchodilators. RESULTS: The administration of inhaled beta agonist bronchodilators leads to the following: (a) a simultaneous increase in abdominal and thoracic pressure not affecting the trans-diaphragmatic pressure gradient and (b) a decrease in the LES resting pressure with a reduction of the LES retention pressure. CONCLUSION: In conclusion, inhaled beta agonist bronchodilators not only increase the thoracic pressure but also lead to an increased abdominal pressure favoring GERD by affecting the esophagogastric barrier.