### Date : 2024-11-12 16:41 ### Topic : Esophageal Achalasia #gastroenterology ---- ### **Esophageal Achalasia** **Esophageal achalasia** is a rare disorder of the esophagus characterized by the **inability of the lower esophageal sphincter (LES) to relax** properly and **loss of peristalsis in the esophageal body**. This results in difficulty swallowing (dysphagia), regurgitation of undigested food, and sometimes chest pain. --- ### **Pathophysiology** 1. **LES Dysfunction**: - The LES fails to relax due to degeneration of inhibitory neurons (primarily those that release nitric oxide) in the **myenteric plexus** (Auerbach's plexus) of the esophagus. - This leads to constant high resting pressure in the LES. 2. **Loss of Peristalsis**: - The esophageal body loses its ability to perform coordinated contractions due to nerve degeneration. - As a result, swallowed food cannot move effectively into the stomach. 3. **Progressive Dilation**: - Over time, the esophagus dilates above the tight LES, forming a "bird-beak" appearance on imaging. --- ### **Causes of Achalasia** 1. **Primary Achalasia** (Idiopathic): - The exact cause is unknown but thought to be autoimmune or neurodegenerative. - Degeneration of inhibitory neurons in the myenteric plexus is a hallmark. 2. **Secondary Achalasia (Pseudoachalasia)**: - Caused by conditions that mimic achalasia, such as: - **Chagas Disease**: Infection with *Trypanosoma cruzi*, leading to destruction of the myenteric plexus. - **Malignancy**: Esophageal or gastric tumors invading the LES. - **Other Disorders**: Amyloidosis, sarcoidosis, or neurodegenerative diseases. --- ### **Clinical Features** 1. **Dysphagia**: - Difficulty swallowing, initially for solids and later for liquids. - The most common presenting symptom. 2. **Regurgitation**: - Undigested food may be regurgitated, especially when lying down. - Increases the risk of aspiration pneumonia. 3. **Chest Pain**: - Intermittent and non-specific; may mimic angina. - Caused by esophageal spasm or food retention. 4. **Weight Loss**: - Due to difficulty eating and inadequate calorie intake. 5. **Nocturnal Symptoms**: - Patients may experience coughing or choking at night due to regurgitation and aspiration. --- ### **Diagnosis** 1. **Esophageal Manometry** (Gold Standard): - Confirms diagnosis by showing: - **Incomplete LES relaxation**. - **High LES resting pressure**. - **Absence of peristalsis** in the esophageal body. 2. **Barium Swallow Study**: - Reveals the classic **"bird-beak" appearance** of the distal esophagus due to the narrowed LES and dilated proximal esophagus. 3. **Endoscopy**: - Used to rule out secondary causes like malignancy or strictures. - May show food retention or esophageal dilation. 4. **CT Scan or EUS (Endoscopic Ultrasound)**: - Performed when malignancy is suspected as a cause of pseudoachalasia. --- ### **Classification of Achalasia** Achalasia is classified into three types based on manometric findings (Chicago Classification): 1. **Type I (Classic Achalasia)**: - No peristalsis and minimal esophageal pressurization. 2. **Type II (Achalasia with Compression)**: - No peristalsis, but pan-esophageal pressurization is seen. - Responds best to treatment. 3. **Type III (Spastic Achalasia)**: - Premature, spastic contractions in the esophagus. - Often associated with more chest pain. --- ### **Treatment of Esophageal Achalasia** The goal of treatment is to relieve symptoms by reducing LES pressure and improving esophageal emptying. Options include: #### **Non-Surgical Approaches** 1. **Pneumatic Dilation**: - A balloon is used to stretch and partially tear the LES muscle. - Effective in reducing symptoms, but may require repeated procedures. 2. **Botulinum Toxin Injection**: - Injected directly into the LES via endoscopy to inhibit muscle contraction. - Temporary relief (lasting 3-6 months); often used in patients who are not surgical candidates. 3. **Medications**: - **Nitrates** (e.g., isosorbide dinitrate) or **calcium channel blockers** (e.g., nifedipine) to relax the LES. - Used as adjunctive therapy, but less effective. #### **Surgical Approaches** 1. **Heller Myotomy**: - A laparoscopic procedure where the LES is surgically divided to allow better passage of food. - Often combined with a partial fundoplication to prevent reflux. 2. **Peroral Endoscopic Myotomy (POEM)**: - A minimally invasive endoscopic procedure that involves cutting the LES muscle. - Effective for all types of achalasia, including spastic variants. --- ### **Prognosis** - With appropriate treatment, most patients experience significant symptom relief. - However, complications like gastroesophageal reflux disease (GERD) are common after myotomy or dilation, requiring long-term management with proton pump inhibitors (PPIs). --- ### **Complications** 1. **Aspiration Pneumonia**: - Regurgitated food can enter the lungs, leading to infection. 2. **Esophageal Dilation and Stasis**: - Long-term stasis of food can cause esophagitis and increased risk of malignancy (esophageal squamous cell carcinoma). 3. **Reflux Esophagitis**: - A common complication after LES-relaxing treatments. --- ### **Summary** - **Esophageal Achalasia** is characterized by LES dysfunction and loss of esophageal peristalsis, leading to dysphagia, regurgitation, and chest pain. - Diagnosis relies on **manometry**, **barium swallow**, and **endoscopy**. - Treatment includes **pneumatic dilation**, **botulinum toxin injection**, and surgical options like **Heller myotomy** or **POEM**. - Early diagnosis and treatment can improve symptoms and prevent complications. ### Reference: - ### Connected Documents: -