GERD & Barrett's Esophagus for the American Board of Internal Medicine (ABIM) Exam
Gastroesophageal Reflux Disease (GERD) and Barrett’s Esophagus for ABIM Exam
Definition
- Gastroesophageal Reflux Disease (GERD): A chronic condition characterized by the retrograde flow of gastric contents into the esophagus, leading to symptoms like heartburn, regurgitation, and, in severe cases, esophagitis or other complications. GERD occurs due to dysfunction of the lower esophageal sphincter (LES).
- Barrett’s Esophagus: A premalignant condition in which chronic GERD causes metaplasia, with the normal stratified squamous epithelium of the esophagus being replaced by columnar epithelium with intestinal features. This increases the risk of developing esophageal adenocarcinoma.
Pathophysiology
GERD
- Lower Esophageal Sphincter (LES) Dysfunction:
- The LES may relax inappropriately (transient LES relaxations) or have low resting tone, allowing reflux of acidic gastric contents into the esophagus.
- Hiatal Hernia: A structural defect where part of the stomach herniates through the diaphragm, weakening the LES and increasing reflux.
- Delayed Gastric Emptying: Causes increased intra-abdominal pressure, which can push gastric contents back into the esophagus.
- Esophageal Mucosal Damage: Recurrent exposure of the esophageal mucosa to acidic or bile-containing gastric contents can lead to inflammation (esophagitis), erosions, ulcers, and potential development of Barrett's esophagus.
Barrett’s Esophagus
- Metaplasia: In response to chronic acid exposure from GERD, the squamous epithelium of the esophagus transforms into columnar epithelium with goblet cells (intestinal metaplasia), which is more resistant to acid but carries an increased risk of malignant transformation.
- Progression to Dysplasia and Cancer: Barrett’s esophagus can progress to low-grade dysplasia, high-grade dysplasia, and eventually esophageal adenocarcinoma if not managed appropriately.
Risk Factors
GERD
- Obesity: Increases intra-abdominal pressure, promoting reflux.
- Pregnancy: Hormonal changes and increased intra-abdominal pressure contribute to GERD.
- Hiatal Hernia: Disrupts the LES and allows reflux.
- Smoking: Lowers LES tone and increases acid production.
- Dietary Triggers: Fatty foods, caffeine, alcohol, chocolate, and spicy foods relax the LES and exacerbate symptoms.
- Medications: Calcium channel blockers, nitrates, and anticholinergics relax the LES, increasing reflux.
Barrett’s Esophagus
- Chronic GERD: The most important risk factor for Barrett’s esophagus. Prolonged and severe GERD increases the likelihood of developing metaplasia.
- Age and Gender: Barrett’s esophagus is more common in older adults, particularly white males over the age of 50.
- Smoking: Increases the risk of progression from Barrett’s esophagus to esophageal adenocarcinoma.
- Obesity: Particularly central obesity, increases the risk due to increased intra-abdominal pressure.
Clinical Features
GERD
- Heartburn: A burning sensation in the retrosternal area, usually occurring after meals or when lying down.
- Regurgitation: The sensation of gastric contents moving back into the throat or mouth.
- Dysphagia: Difficulty swallowing, often due to inflammation, strictures, or severe esophagitis.
- Atypical Symptoms: Chronic cough, hoarseness, asthma exacerbations, or chest pain (non-cardiac).
Barrett’s Esophagus
- Often Asymptomatic: Barrett’s esophagus itself does not cause specific symptoms; the condition is typically discovered during endoscopy for GERD evaluation.
- Worsening GERD Symptoms: Some patients may report more frequent or severe GERD symptoms as the metaplasia progresses.
- Alarm Symptoms: Dysphagia, odynophagia (painful swallowing), weight loss, and GI bleeding (hematemesis or melena) may indicate complications like strictures, ulceration, or malignancy.
Diagnosis
GERD
- Clinical Diagnosis: GERD is often diagnosed based on symptoms (heartburn, regurgitation) and the response to empirical treatment with proton pump inhibitors (PPIs).
- Endoscopy:
- Performed if there are alarm symptoms, treatment-resistant GERD, or to evaluate for complications (e.g., esophagitis, strictures, Barrett’s esophagus).
- Findings: Esophagitis, erosions, ulcers, or hiatal hernia.
- 24-hour Esophageal pH Monitoring:
- Used to confirm GERD in patients with atypical symptoms or when the diagnosis is uncertain. Measures the amount of acid reflux into the esophagus.
- Esophageal Manometry:
- Assesses LES function and esophageal motility, especially in patients with dysphagia or before anti-reflux surgery.
Barrett’s Esophagus
- Endoscopy with Biopsy:
- The gold standard for diagnosing Barrett’s esophagus. Intestinal metaplasia is confirmed by the presence of goblet cells on biopsy.
- Endoscopic surveillance is recommended for patients with confirmed Barrett’s to monitor for dysplasia or early cancer.
- Surveillance Intervals:
- For non-dysplastic Barrett's esophagus, endoscopy every 3-5 years is recommended.
- For Barrett’s with low-grade or high-grade dysplasia, more frequent endoscopy or therapeutic intervention is necessary.
Treatment
GERD
- Lifestyle Modifications:
- Weight loss: Reduces intra-abdominal pressure and reflux.
- Dietary changes: Avoid trigger foods (e.g., fatty foods, caffeine, alcohol, chocolate).
- Elevating the head of the bed: Reduces nighttime reflux.
- Avoid lying down after meals: Wait 2-3 hours after eating before lying down.
- Smoking cessation: Improves LES tone and reduces symptoms.
- Pharmacologic Therapy:
- Proton Pump Inhibitors (PPIs): First-line treatment. Suppress gastric acid production and promote healing of esophagitis.
- Common agents: omeprazole, pantoprazole, esomeprazole.
- H2-Receptor Antagonists (H2RAs): For patients with mild or intermittent symptoms.
- Less effective than PPIs but useful for mild cases or nighttime symptom control.
- Antacids: Provide rapid relief of mild symptoms but are not suitable for chronic management.
- Surgical Management:
- Fundoplication: An anti-reflux surgery in which the fundus of the stomach is wrapped around the LES to reinforce its function.
- Considered for patients with refractory GERD, intolerant to medications, or with large hiatal hernias.
Barrett’s Esophagus
- PPI Therapy: Chronic acid suppression with PPIs helps reduce acid reflux and may prevent the progression of Barrett’s esophagus.
- Endoscopic Surveillance: Regular endoscopy with biopsies to monitor for dysplasia.
- Treatment of Dysplasia:
- Endoscopic Ablation Therapy: Used for Barrett’s with low-grade or high-grade dysplasia.
- Radiofrequency Ablation (RFA): Ablates the abnormal epithelium, allowing normal squamous epithelium to regenerate.
- Endoscopic Mucosal Resection (EMR): Removes dysplastic or early cancerous tissue during endoscopy.
- Esophagectomy: Considered in patients with high-grade dysplasia or early adenocarcinoma if endoscopic therapy is not feasible or successful.
Complications
GERD
- Erosive Esophagitis: Inflammation leading to erosions and ulcers in the esophagus.
- Esophageal Strictures: Chronic inflammation and scarring can cause narrowing, leading to dysphagia.
- Aspiration Pneumonia: Chronic reflux can lead to aspiration of gastric contents, causing respiratory infections or chronic cough.
Barrett’s Esophagus
- Esophageal Adenocarcinoma: The major long-term complication of Barrett’s esophagus. Patients with Barrett’s are at increased risk of developing esophageal cancer, especially if dysplasia is present.
Prevention
- GERD Management: Effective long-term management of GERD with lifestyle modifications and acid suppression therapy reduces the risk of Barrett’s esophagus.
- Surveillance in Barrett’s Esophagus: Regular endoscopic surveillance helps detect dysplasia early and prevent progression to adenocarcinoma.
Key Points
- GERD is caused by dysfunction of the LES, leading to acid reflux and symptoms such as heartburn and regurgitation.
- Barrett’s esophagus is a premalignant condition resulting from chronic GERD, where the esophageal squamous epithelium undergoes metaplasia.
- Diagnosis of GERD is primarily clinical, with endoscopy reserved for patients with alarm symptoms or refractory cases. Barrett’s esophagus is diagnosed via endoscopy and biopsy.
- Treatment of GERD includes lifestyle modifications, PPIs, and surgery for refractory cases. Barrett’s esophagus requires regular surveillance and may require endoscopic or surgical intervention if dysplasia is present.
- Complications include erosive esophagitis, esophageal strictures, and an increased risk of esophageal adenocarcinoma in