Gastroesophageal Reflux Disease (GERD) and Barrett’s Esophagus for USMLE Step 3

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Gastroesophageal Reflux Disease (GERD) and Barrett’s Esophagus for USMLE Step 3

Definition

Gastroesophageal Reflux Disease (GERD): A chronic condition where gastric contents reflux into the esophagus due to lower esophageal sphincter (LES) dysfunction, causing symptoms like heartburn, regurgitation, and potential esophageal damage.

Barrett’s Esophagus: A premalignant condition resulting from chronic GERD, where normal squamous epithelium of the esophagus is replaced by columnar epithelium with intestinal metaplasia, increasing the risk of esophageal adenocarcinoma.

Pathophysiology

GERD

LES Dysfunction: Transient relaxations or hypotension of the LES allow acid reflux into the esophagus.
Hiatal Hernia: Structural abnormality where part of the stomach herniates through the diaphragm, promoting reflux.
Mucosal Injury: Repeated exposure to gastric acid damages the esophageal mucosa, leading to inflammation (esophagitis), ulcerations, and possibly Barrett’s esophagus.

Barrett’s Esophagus

Chronic Acid Exposure: Persistent reflux causes the normal squamous epithelium to be replaced by columnar epithelium with goblet cells (intestinal metaplasia), more resistant to acid.
Progression: Barrett’s esophagus can progress to dysplasia, increasing the risk of developing esophageal adenocarcinoma.

Risk Factors

GERD

Obesity: Increased intra-abdominal pressure promotes reflux.
Smoking: Lowers LES tone and increases gastric acid production.
Dietary Triggers: Fatty foods, caffeine, alcohol, and chocolate weaken the LES, exacerbating symptoms.
Pregnancy: Increased intra-abdominal pressure and hormonal changes contribute to reflux.

Barrett’s Esophagus

Chronic GERD: The strongest risk factor for Barrett’s esophagus.
Male Gender and Age: More common in men over 50.
Smoking and Obesity: Both are associated with an increased risk of Barrett’s and esophageal cancer.

Clinical Features

GERD

Heartburn: Retrosternal burning pain, often after meals or when lying down.
Regurgitation: Acid or food returning to the throat or mouth.
Dysphagia: Difficulty swallowing due to esophageal inflammation or strictures.
Atypical Symptoms: Chronic cough, hoarseness, asthma exacerbations, or non-cardiac chest pain.

Barrett’s Esophagus

Asymptomatic: Usually discovered during evaluation for GERD; Barrett’s itself does not cause specific symptoms.
Persistent GERD Symptoms: GERD symptoms may be more severe or long-standing.
Alarm Symptoms: Dysphagia, weight loss, or gastrointestinal bleeding (hematemesis or melena) suggest complications like malignancy or strictures.

Diagnosis

GERD

Clinical Diagnosis: Based on typical symptoms like heartburn and regurgitation, confirmed by response to proton pump inhibitors (PPIs).
Endoscopy: Indicated in patients with alarm symptoms (e.g., dysphagia, weight loss) or refractory GERD. Can detect complications like esophagitis or Barrett’s esophagus.
24-hour pH Monitoring: Measures esophageal acid exposure and is used to confirm GERD in patients with atypical symptoms.

Barrett’s Esophagus

Endoscopy with Biopsy: The gold standard for diagnosing Barrett’s esophagus, confirming intestinal metaplasia with goblet cells.
Surveillance Endoscopy: Regular endoscopy is recommended for patients with Barrett’s esophagus to monitor for dysplasia or progression to adenocarcinoma.

Treatment

GERD

Lifestyle Modifications: Weight loss, avoid trigger foods (e.g., caffeine, alcohol, fatty foods), elevate the head of the bed, and avoid lying down after meals.
Proton Pump Inhibitors (PPIs): First-line treatment. PPIs reduce gastric acid production and heal esophagitis.
H2-Receptor Antagonists: Used for mild or intermittent symptoms.
Surgery (Fundoplication): Recommended for patients with refractory GERD or large hiatal hernias.

Barrett’s Esophagus

PPI Therapy: Long-term PPI use reduces acid exposure and may prevent the progression of Barrett’s esophagus.
Endoscopic Surveillance: Regular endoscopic evaluations with biopsies to monitor for dysplasia or cancer.
Endoscopic Ablation: For dysplastic Barrett’s, techniques like radiofrequency ablation (RFA) or endoscopic mucosal resection (EMR) remove or destroy abnormal tissue to prevent cancer.

Complications

GERD

Erosive Esophagitis: Inflammation leading to erosions or ulcers.
Esophageal Strictures: Chronic inflammation causes scarring and narrowing, leading to dysphagia.
Aspiration Pneumonia: Refluxed gastric contents may be aspirated into the lungs, leading to pneumonia.

Barrett’s Esophagus

Esophageal Adenocarcinoma: Barrett’s esophagus significantly increases the risk of esophageal adenocarcinoma, especially if dysplasia is present.

Prevention

GERD Management: Long-term treatment with PPIs and lifestyle changes can reduce the risk of developing Barrett’s esophagus.
Surveillance: Regular endoscopy in Barrett’s esophagus helps detect dysplasia early and prevent progression to cancer.

Key Points

GERD results from LES dysfunction, causing reflux of gastric contents and symptoms like heartburn and regurgitation.
Barrett’s esophagus is a complication of chronic GERD and increases the risk of esophageal adenocarcinoma.
Diagnosis of GERD is often clinical, but endoscopy is used for patients with alarm symptoms or refractory disease. Barrett’s esophagus is diagnosed with endoscopy and biopsy.
Treatment of GERD includes lifestyle changes and PPIs, while Barrett’s esophagus requires endoscopic surveillance and ablation for dysplasia.
Complications of GERD include esophagitis, strictures, and aspiration pneumonia. Barrett’s esophagus increases the risk of esophageal cancer.