"Treat acid pocket" and follow up high-risk patients endoscopically

Gastroesophageal reflux disease ( GERD) is the most common benign disease of the upper gastrointestinal tract in the Western world. For symptomatic treatment, it is recommended to use alginates in PPI-refractory reflux symptoms. Chronic acid exposure of the esophagus can lead to complications such as reflux esophagitis, peptic stenosis, Barrett’s esophagus, or adenocarcinoma. As a recent study shows, esophageal adenocarcinoma is affecting more and more people under 50 years of age.

20-30% of the Swiss population suffer from reflux symptoms [1]. If left untreated, may cause inflammation of the esophagus, which, if chronic, may lead to the development of stenosis or tumor in the esophagus. In 1-2% of patients, the top layer of the esophagus changes into a so-called Barrett’s mucosa. In very rare cases, it can develop into cancer.

GERD as a risk factor for esophageal adenocarcinoma.

Esophageal cancer is the seventh most common cancer worldwide, with approximately 500,000 people dying from it each year [2,3]. The most clinically relevant forms are adenocarcinomas and squamous cell carcinomas. Adenocarcinomas are almost always based on Barrett’s esophagus secondary to gastroesophageal reflux disease (GERD). Obesity and smoking are other important risk factors. The diagnosis of esophageal cancer is made endoscopically by esophagogastroduodenoscopy and esophageal gross examination. “The incidence of esophageal adenocarcinoma is increasing among young adults,” said Ali Al-Kaabi, MD, Radboud University Medical Centre, Nijmegen (NL). According to a study from the Netherlands presented at the United European Gastroenterology (UEG) Week 2021, the number of esophageal cancer cases in people under 50 years of age has tripled over the past 30 years [4] (box) . Symptoms of esophageal cancer such as difficulty swallowing, nausea, heartburn, and indigestion can be confused with other gastrointestinal complaints. The study findings suggest the importance of further diagnostic workup in high-risk groups with appropriate symptoms – particularly in under-50 smokers and overweight individuals – to increase survival, Dr. Al-Kaabi said. As cancer screening, regular endoscopic follow-up is recommended in high-risk patients.

Gastroesophageal reflux episodes: “acid pocket” in focus

GERD is a motility disorder caused by the weakened barrier between the stomach and esophagus. Acid reflux following food intake is the predominant factor in gastroesophageal reflux disease. In the postprandial phase, an accumulation of acid, called an “acid pocket,” forms in the stomach below the esophageal sphincter on top of the food pulp. In reflux disease, the contents of these can enter the esophagus and trigger postprandial heartburn. The acid pocket is present in both healthy individuals and reflux patients, but particularly in patients with hiatal hernia and/or hypotensive lower esophageal sphincter, the acid pocket may extend beyond the gastroesophageal junction into the distal esophagus [5]. This leads to increased acid exposure, especially of the most distal esophageal segment, and thus to reflux symptoms. In recent years, the acid pocket has been postulated as a possible target of pharmacologic and surgical GERD therapies. While acid inhibiting medications such as proton pump inhibitors (PPI) reduce acidity of the acid pocket, alginate substances, prokinetics, and fundoplication surgery dislocate the acid pocket distally away from the gastroesophageal junction.

Alginates should be considered if there is an inadequate response to PPI

According to the Lyon Consensus Conference, the diagnosis of GERD is considered confirmed when there is severe reflux esophagitis (Los-Angeles grade C or D), peptic stricture, histologically confirmed Barrett’s metaplasia greater than 1 cm, or esophageal acid exposure of >6% of the measured time (24 h) [6]. GERD is considered excluded with acid exposure <4% and <40 reflux episodes per day [6]. Proton pump inhibitors (PPIs) lead to a satisfactory therapeutic effect in about 70% of patients with reflux symptoms [7]. About one-third of GERD patients, however, cannot be satisfactorily treated with PPI. In these patients, differentiated esophageal functional diagnostics and further therapeutic measures are recommended (Fig. 1) [9,10]. Alginates have proven effective as an add-on or alternative treatment option in PPI-refractory cases. By allowing alginate to form a stable alginic acid gel in the acidic environment of the stomach, which is deposited on the surface of the Acid Pocket within a few minutes and serves as a pH-neutral protection, reflux is mechanically prevented [8]. The inclusion of_CO2 from the hydrogen carbonate contained in the preparation, which at the same time neutralizes part of the stomach acid, gives the gel the necessary buoyancy.

Congress: United European Gastroenterology Week 2021

Literature:

KSSG: Reflux, Gastroesophageal Reflux Disease (GERD), www.kssg.ch/gastroenterologie-hepatologie/leistungsangebot/reflux (last accessed 07/10/21).
Huang J, et al: Global Burden, Risk Factors, and Trends of Esophageal Cancer: An Analysis of Cancer Registries from 48 Countries. Cancers (Basel) 2021; 13(1): 141.
GBD 2017 Esophageal Cancer Collaborators, The Lancet Gastroenterology & Hepatology, 2020; 5(6): 582-597.
“Oesophageal adenocarcinoma cases triple in younger people over past 30 years, new study finds,” UEG Week Virtual, Vienna, Oct. 5, 2021.
Sauter M, Fox MR: The acid pocket: a new target for the treatment of gastroesophageal reflux disease. Z Gastroenterol 2018; 56(10): 1276-1282.
Gyawali CP, et al: Modern diagnosis of GERD: the Lyon consensus. Gut 2018; 67: 1351-1362.
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