Achalasia: Causes, Symptom and Treatment

Achalasia is a rare but impactful condition that affects the esophagus, the muscular tube responsible for moving food from the mouth to the stomach.

This disorder can significantly affect one’s quality of life, making eating and drinking a challenge. Understanding achalasia, from its causes to treatment options, is essential for managing it effectively.

What is Achalasia?

Achalasia is a condition where the lower esophageal sphincter (LES)—the ring of muscle between the esophagus and stomach—fails to relax properly.

This leads to difficulty in swallowing, as food and liquids struggle to pass into the stomach. Over time, the esophagus can become dilated and lose its ability to push food effectively.

Globally, achalasia affects approximately 1 in 100,000 people annually. It is equally common in men and women and typically presents between the ages of 25 and 60. While rare, its progressive nature requires timely diagnosis and treatment.

How Does Achalasia Occur?

The pathophysiology of achalasia revolves around the dysfunction of the LES and the esophageal muscles.

Normally, the LES relaxes to allow food to enter the stomach. In achalasia, nerve cells (myenteric plexus) in the esophageal wall degenerate, disrupting this process.

Imagine the esophagus as a conveyor belt. In achalasia, the motor controlling the belt (nerves) is damaged, causing food to get stuck. Over time, the conveyor belt becomes less functional, leading to further complications.

What Are the Causes of Achalasia?

While the exact cause of achalasia remains unclear, several factors have been linked to its development:

• Idiopathic degeneration: In most cases (80-90%), the exact trigger for nerve damage is unknown.
• Autoimmune factors: Some theories suggest the immune system mistakenly attacks the esophageal nerves.
• Infections: Certain infections, such as those caused by Trypanosoma cruzi (Chagas disease), can lead to secondary achalasia.
• Genetics: Rare familial cases suggest a potential genetic component.

What Are the Risk Factors?

Although achalasia is not a lifestyle-related disease, some factors may increase the likelihood of developing it:

1. Age: Most cases occur in individuals aged 25-60.
2. Chronic infections: Particularly in regions where Chagas disease is prevalent.
3. Family history: Rare genetic mutations linked to achalasia may run in families.
4. Autoimmune diseases: Conditions like lupus or scleroderma may heighten the risk.

Among these, idiopathic cases remain the most common, highlighting the disease’s enigmatic nature.

Symptoms of Achalasia

The symptoms of achalasia often develop gradually but worsen over time. Key symptoms include:

1. Dysphagia (difficulty swallowing): This is the hallmark symptom, affecting both solids and liquids.
2. Regurgitation: Undigested food and saliva may flow back into the mouth.
3. Chest pain: A result of esophageal spasms, it can mimic heart-related pain.
4. Weight loss: Caused by reduced food intake.
5. Heartburn: Despite the name, this is due to retained food rather than acid reflux.
6. Aspiration: Food or liquids entering the airway can lead to coughing or recurrent respiratory infections.

These symptoms arise because the esophagus cannot effectively push food into the stomach, causing a backlog.

Differential Diagnosis

Achalasia shares symptoms with other conditions, making its diagnosis challenging without specific tests. Common conditions to consider include:

1. Gastroesophageal reflux disease (GERD): Though GERD causes heartburn, it is due to acid reflux rather than esophageal dysfunction.
2. Esophageal stricture: Narrowing of the esophagus, often due to scarring or cancer.
3. Scleroderma: A connective tissue disorder affecting esophageal motility.
4. Zenker’s diverticulum: A pouch in the esophagus that traps food.

Differentiating these conditions requires detailed clinical evaluation and diagnostic tests.

How to Diagnose Achalasia?

Diagnosing achalasia involves a combination of clinical history, imaging, and specialized tests. The gold standard investigation is esophageal manometry. Here’s how it works:

1. Esophageal Manometry: A thin tube with pressure sensors is passed into the esophagus. This measures the muscle contractions and determines whether the LES is relaxing properly.
2. Barium Swallow X-ray: Patients drink a barium solution, and X-rays are taken. A characteristic “bird’s beak” narrowing at the LES is a hallmark finding.
3. Endoscopy: This allows direct visualization of the esophagus and rules out conditions like cancer or strictures.

Together, these tests confirm the diagnosis and rule out other potential causes.

Treatment of Achalasia

Treatment focuses on relieving symptoms by reducing LES pressure and improving esophageal emptying. Options include:

1. Medical Management

• Nitrates and calcium channel blockers: These medications relax the LES but provide only temporary relief.
• Botulinum toxin (Botox) injection: Injected into the LES, Botox temporarily reduces pressure but requires repeated treatments.

2. Non-Surgical Interventions

• Pneumatic dilation: A balloon is inserted into the LES and inflated to widen it. This provides long-term relief for many patients but may require multiple sessions.

3. Surgical Treatments

• Heller myotomy: This minimally invasive surgery cuts the LES muscle to reduce pressure. It is often combined with a fundoplication (wrapping the stomach around the esophagus) to prevent reflux.
• Peroral endoscopic myotomy (POEM): A newer, incision-free technique that achieves similar results to Heller myotomy.

4. Lifestyle Modifications

• Eating smaller meals.
• Avoiding lying down after eating.
• Elevating the head of the bed to minimize regurgitation.

For severe cases, esophagectomy (removal of the esophagus) may be considered, though it is rare.

Prognosis and Follow-Up

With appropriate treatment, most patients experience significant symptom relief. However, achalasia is a chronic condition, and long-term follow-up is essential to monitor for complications like:

• Esophageal dilation.
• Risk of esophageal cancer, particularly squamous cell carcinoma.

Patients should remain under regular medical care to address emerging concerns.

References

1. Vaezi, M. F., et al. (2022). Achalasia: Clinical features and diagnosis. The Lancet Gastroenterology & Hepatology.
2. Pandolfino, J. E., & Gawron, A. J. (2015). Achalasia: A systematic review. JAMA.
3. Patel, D. A., et al. (2021). Modern management of achalasia. Annals of Thoracic Surgery.