Effect of Increased Intra-abdominal Pressure on the Esophagogastric Junction: A Systematic Review

With the advent of high-resolution esophageal manometry, it is recognized that the antireflux barrier receives a contribution from both the lower esophageal sphincter (intrinsic sphincter) and the muscle of the crural diaphragm (extrinsic sphincter). Further, an increased intra-abdominal pressure is a major force responsible for an adaptive response of a competent sphincter or the disruption of the esophagogastric junction resulting in gastroesophageal reflux, especially in the presence of a hiatal hernia. This review describes how the pressure dynamics in the lower esophageal sphincter were discovered and measured over time and how this has influenced the development of antireflux surgery.

Severity of GERD and disease progression

BACKGROUND

Many factors may play a role in the severity and progression of gastroesophageal reflux disease (GERD) since pathophysiology is multifactorial. Data regarding the progression of GERD are controversial: some reports of increased esophageal acid exposure (EAE) and mucosal damage were considered as evidence for a stable disease course, while others interprete these findings as disease progression. The aim of this study is to analyze a large patient-population with persisting symptoms indicative of GERD under protonpumpinhibitor-therapy and identify components characterizing disease severity and progression.

METHODS

Patients with symptoms indicative of GERD were included in the study in a tertiary referral center (Frankfurt, Germany). All selected patients were under long-term protonpumpinhibitor-therapy with persistant symptoms. All patients underwent investigations to collect data on their physical status, EAE, severity of esophagitis, anatomical changes, and esophageal functional defects as well as their relation to the duration of the disease. Incidence over time was plotted as survival curves and tested with Log-rank tests for the four main disease markers. Multivariate modeling with COX-regression model was used to estimate the general impact of the four main disease markers on the time course of the disease. In order to elucidate possible causal relationships over time, a path analysis (structural equation model) was calculated.

RESULTS

From the database with 1480 data sets, 972 patients were evaluated (542 males, 430 females). The mean age was 50.5 years (range18-89). The mean body mass index was 27.2(19-48). The mean time between the onset of symptoms and the diagnostic investigations was 8.2 years (1-50). A longer disease history for GERD was significantly associated with a higher risk for LES-incompetence. The mean duration from symptom onset to the time of clinical investigation was 9 years for patients with LES-incompetence (n = 563), compared to a mean of 6 years for those with mechanically intact LES (n = 95). A longer period from symptom onset to diagnostics was significantly associated with higher acid exposure. The pathway analysis was significant for the following model: 'history' (P < 0.001➔LES-incompetence & Hiatal Hernia➔(p < 0,001)➔pH-score (P < 0.001).Conclusion: LES-incompetence, the functional deterioration of the LES, and the anatomical alteration at the esophagogastric junction (Hiatal Hernia) as well as an increased EAE were associated with a long history of suffering from GERD. Path modeling suggests a causal sequence overtime of the main disease-parameters, tentatively allowing for a prediction of the course of the disease.

Relationship between esophageal motility and severity of gastroesophageal reflux disease according to the Los Angeles classification

The current study aimed to investigate the relationship between the severity of gastroesophageal reflux disease (GERD) according to the Los Angeles (LA) classification and esophageal motility using high-resolution manometry (HRM) and 24-hour esophageal pH monitoring.We examined 124 patients with GERD from January 2016 to June 2018. The LA classification of each patient was determined by endoscopy. HRM was performed by the intraluminal water infusion method. HRM and 24-hour esophageal pH monitoring parameters of the patients were studied and statistically compared.On HRM examination, GERD symptoms were found to be associated with worsened distal contractile integral (DCI), ineffective esophageal motility (IEM), peristalsis break (PB), lower esophageal sphincter (LES) pressure, and the 4-second integrated relaxation pressure (IRP4s) of LES pressure along with the grade of LA classification, especially in patients having grade C and D GERD who had transverse mucosal breaks. The 24-hour pH monitoring study revealed that patients classified as having grade C or D GERD had an esophageal pH < 4.0 for a longer time than those with grade O, A, or B GERD. Similar results were found regarding the duration of the longest reflux event, the number of reflux episodes longer than 5 minutes, and the number of reflux episodes. Patients with higher grade esophagitis had higher De Meester scores, which suggested greater esophageal acid exposure. Hiatal hernia (HH) was more closely related to LES pressure, IRP4s, and acid exposure, whereas DCI, IEM, and PB were not statistically different between patients with GERD with and without HH.Patients with severe esophagitis may have motor dysfunction not only in the LES but also in the esophageal body, with resulting increased esophageal acid exposure, which causes esophagitis. Low LES pressure might be the main reason that patients with HH develop esophagitis. GERD without HH may be due to a variety of motor dysfunctions.

Ambulatory reflux monitoring for diagnosis of gastro-esophageal reflux disease: Update of the Porto consensus and recommendations from an international consensus group

BACKGROUND

An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro-esophageal reflux disease (GERD).

METHODS

Literature search was focused on indications and technical recommendations for GERD testing and phenotypes definitions. Statements were proposed and discussed during several structured meetings.

KEY RESULTS

Reflux testing should be performed after cessation of acid suppressive medication in patients with a low likelihood of GERD. In this setting, testing can be either catheter-based or wireless pH-monitoring or pH-impedance monitoring. In patients with a high probability of GERD (esophagitis grade C and D, histology proven Barrett's mucosa >1 cm, peptic stricture, previous positive pH monitoring) and persistent symptoms, pH-impedance monitoring should be performed on treatment. Recommendations are provided for data acquisition and analysis. Esophageal acid exposure is considered as pathological if acid exposure time (AET) is greater than 6% on pH testing. Number of reflux episodes and baseline impedance are exploratory metrics that may complement AET. Positive symptom reflux association is defined as symptom index (SI) >50% or symptom association probability (SAP) >95%. A positive symptom-reflux association in the absence of pathological AET defines hypersensitivity to reflux.

CONCLUSIONS AND INFERENCES

The consensus group determined that grade C or D esophagitis, peptic stricture, histology proven Barrett's mucosa >1 cm, and esophageal acid exposure greater >6% are sufficient to define pathological GERD. Further testing should be considered when none of these criteria are fulfilled.