What causes esophageal stricture

Overview

An esophageal stricture is a medical condition characterized by the narrowing or tightening of the esophagus, the muscular tube that connects the throat to the stomach. This narrowing can impede the passage of food and liquids, leading to symptoms like difficulty swallowing (dysphagia), pain during swallowing, a sensation of food getting stuck, regurgitation, and unintended weight loss. Understanding the causes of esophageal strictures is crucial for effective diagnosis and treatment.

Common Causes of Esophageal Stricture

The underlying mechanism for most esophageal strictures involves damage to the esophageal lining, followed by an inflammatory response and subsequent scarring. This scar tissue is less flexible than healthy tissue and can contract over time, leading to a progressive narrowing of the esophageal lumen.

Gastroesophageal Reflux Disease (GERD)

GERD is by far the most frequent culprit behind esophageal strictures, particularly peptic strictures. In GERD, stomach acid and contents frequently back up into the esophagus. The esophagus is not designed to withstand prolonged exposure to stomach acid, which is highly corrosive. Chronic exposure leads to inflammation (esophagitis), ulceration, and eventual scarring. Over time, this chronic damage can cause the esophageal tissue to heal with scar tissue, leading to a stricture. It's estimated that up to 50% of individuals with long-standing, severe GERD may develop a peptic stricture. The severity and duration of untreated GERD are key factors in stricture formation.

Eosinophilic Esophagitis (EoE)

EoE is an immune-mediated, allergic inflammatory disease that affects the esophagus. It is characterized by an accumulation of eosinophils, a type of white blood cell, in the esophageal lining. EoE often presents in childhood or early adulthood and is frequently associated with other allergic conditions like asthma, eczema, and food allergies. The chronic inflammation caused by EoE can lead to significant tissue remodeling, fibrosis, and the development of esophageal strictures. Studies suggest that around 20% of patients diagnosed with EoE will develop a stricture. Distinguishing EoE strictures from peptic strictures is important as their management differs.

Radiation Therapy

Radiation therapy, often used to treat cancers of the chest, neck, or upper abdomen, can inadvertently damage the esophageal tissue. The radiation can cause inflammation and fibrosis (scarring) in the esophagus, leading to the formation of a stricture, typically several months to years after treatment. The risk is dose-dependent and depends on the area irradiated. It is estimated that 15% or more of patients undergoing radiation therapy to the chest may develop radiation-induced esophageal strictures.

Ingestion of Corrosive Substances

Accidental or intentional ingestion of strong acids (like battery acid) or alkalis (like drain cleaner or bleach) can cause immediate and severe chemical burns to the esophagus. The damage can be extensive, leading to deep ulcerations, necrosis (tissue death), and significant inflammation. As these severe injuries heal, they often result in extensive scarring and the formation of a tight stricture. These types of strictures can be particularly challenging to treat due to the severity of the initial injury.

Other Causes

While less common, other factors can contribute to esophageal strictures:

• Pills lodged in the esophagus: Certain medications, especially large pills or those that dissolve slowly, can cause irritation and inflammation if they get stuck in the esophagus, leading to localized strictures. Common culprits include potassium chloride supplements, NSAIDs, and bisphosphonates.
• Infections: Certain infections, such as Candida (yeast) or Herpes Simplex Virus (HSV), can cause severe esophagitis, which, if left untreated or if particularly severe, can lead to scarring and strictures.
• Surgical Procedures: Rarely, complications from surgery on the esophagus or surrounding areas can lead to stricture formation.
• Certain Systemic Diseases: Conditions like Crohn's disease or amyloidosis can, in rare instances, affect the esophagus and contribute to stricture development.
• Idiopathic Strictures: In some cases, the cause of an esophageal stricture cannot be identified, and these are termed idiopathic.

Diagnosis and Symptoms

Symptoms of esophageal stricture usually become apparent when the narrowing is significant enough to obstruct food passage. The most common symptom is dysphagia, a feeling of difficulty or pain when swallowing. Food may feel like it's getting stuck in the chest or throat. Other symptoms can include regurgitation of undigested food, heartburn, chest pain, and unintentional weight loss. Diagnosis typically involves an upper endoscopy (esophagogastroduodenoscopy or EGD), where a flexible camera is inserted down the esophagus to visualize the lining and measure the narrowing. Barium swallow X-rays can also be used to assess the size and location of the stricture.

Management

Treatment for esophageal strictures aims to relieve the narrowing and improve swallowing. The primary treatment is usually esophageal dilation, where a balloon or dilator is passed through the stricture to stretch it open. In some cases, surgery may be necessary, especially for very long or complex strictures. Addressing the underlying cause, such as managing GERD or treating EoE, is also a critical part of long-term management to prevent recurrence.