An esophageal stricture is an abnormal narrowing of the esophagus, the muscular tube that transports food and liquids from the mouth to the stomach. This constriction can impede the natural passage of swallowed contents, making it difficult to eat and drink comfortably. Various factors can lead to the formation of scar tissue or other obstructions, reducing its internal diameter.
Inflammation and Acid Damage
Chronic irritation and inflammation are frequent causes of esophageal strictures, often leading to scar tissue formation. Gastroesophageal reflux disease (GERD) is a common cause, where stomach acid repeatedly flows back into the esophagus. This acidic exposure irritates the esophageal lining, causing inflammation (reflux esophagitis). Over time, this consistent irritation results in scar tissue development that contracts, narrowing the esophagus.
Eosinophilic esophagitis (EoE) is another inflammatory condition that can cause strictures. This allergic disorder involves eosinophil accumulation in the esophageal lining. This leads to chronic inflammation, which can stiffen and scar the esophageal tissue, resulting in significant narrowing.
Certain medications can induce localized inflammation and damage if they become lodged in the esophagus, known as pill-induced esophagitis. If a pill dissolves slowly or gets stuck, it can chemically burn the esophageal lining. The healing process involves scar tissue formation, which contracts and creates a localized stricture.
Physical Trauma and External Factors
Direct injury or external influences can also cause strictures through scar tissue formation. Ingesting corrosive substances, such as strong acids or alkalis, causes severe chemical burns to the esophagus. These burns trigger an inflammatory response, leading to extensive tissue damage and subsequent scarring. The resulting dense scar tissue can cause significant narrowing of the esophageal lumen.
Radiation therapy, a common treatment for chest cancers, can also damage healthy esophageal tissue. While targeting cancerous cells, radiation can inadvertently affect the esophagus, causing inflammation and cellular damage. Over time, this damage can induce fibrotic changes and scar tissue formation, resulting in a stricture that may appear months or years after treatment. The degree of stricture depends on the radiation dose and the area exposed.
Surgical procedures on the esophagus, such as for cancer or motility disorders, can sometimes lead to stricture formation. Any surgical incision or anastomosis initiates a healing process involving scar tissue. Sometimes, this natural healing results in excessive scar tissue at the surgical site, causing narrowing. This post-surgical scarring can impede food flow and may require further intervention.
Systemic Diseases and Infections
Systemic diseases and severe infections are also causes of esophageal strictures. Crohn’s disease, a chronic inflammatory bowel condition, can affect any part of the digestive tract, including the esophagus. The inflammation associated with Crohn’s disease can lead to deep ulcers and fibrosis within the esophageal wall, causing strictures as inflamed areas heal with scar tissue.
Scleroderma, an autoimmune disease, can also affect the esophagus. This disorder causes excessive collagen production, leading to hardening and thickening of esophageal tissues. This stiffening can impair normal esophageal function and lead to stricture formation.
Severe or chronic infections can contribute to esophageal strictures, especially in immunocompromised individuals. Fungal infections, such as candidiasis, or viral infections, like herpes simplex, can cause significant inflammation and ulceration of the esophageal lining. If prolonged or severe, the healing process can result in scar tissue formation and a narrowed esophagus.
Tumor Growth
Abnormal tissue growth, whether benign or malignant, can directly cause an esophageal stricture. Tumors physically occupy space within the esophageal lumen, leading to its narrowing. As a tumor enlarges, it can exert pressure on the esophageal walls, reducing the internal diameter and obstructing food passage.
Esophageal cancer is a notable cause of stricture due to the tumor’s mass. As cancerous cells proliferate, they form a solid mass that can directly block the esophagus. The tumor can also induce an inflammatory reaction in surrounding tissues, contributing to fibrotic changes and further narrowing. This combination makes food passage increasingly difficult.