The trachea, commonly referred to as the windpipe, is the tube-like structure responsible for channeling air from the larynx to the lungs. This airway is held open by rings of cartilage, allowing for the unobstructed passage of breath. Tracheal stenosis is defined by an abnormal narrowing of this windpipe. This constriction reduces the space available for air to travel, leading to increasing difficulty with respiration and compromising a person’s ability to breathe adequately.
What Tracheal Stenosis Is
The physical mechanism of tracheal stenosis involves the formation of excess tissue within the airway wall, often as an overzealous healing response to injury. This process typically occurs in the subglottic region, located just below the vocal cords, or within the trachea itself. The resulting scar tissue is rigid and non-compliant, causing the internal diameter of the windpipe to shrink. This narrowing physically restricts the volume of air moving into and out of the lungs. The increased resistance to airflow makes breathing an increasingly strenuous and inefficient process.
The Different Ways Stenosis Develops
Tracheal stenosis is broadly categorized into two main types: congenital, meaning present at birth, and acquired, meaning it develops later in life. Congenital tracheal stenosis is less common and occurs when the cartilage rings of the trachea form abnormally during fetal development. Instead of the typical C-shape, these rings may be complete circles, preventing the trachea from expanding to its normal diameter. This structural abnormality results in a windpipe that is narrower from the beginning, often presenting breathing challenges early in life.
The acquired form of the condition is far more frequent, often resulting from a prior injury or medical procedure. The most common cause of acquired stenosis is prolonged intubation, which involves having a breathing tube placed in the windpipe to assist respiration during surgery or critical illness. The pressure exerted by the tube’s cuff against the tracheal lining causes localized tissue injury and subsequent ulceration. As this injury heals, the body forms scar tissue that contracts over time and narrows the airway.
Other Acquired Causes
Other causes of acquired tracheal stenosis include external trauma to the neck and inflammatory conditions. In all these instances, the narrowing is a direct result of the body’s attempt to repair damaged tissue.
- External trauma to the neck.
- Inflammatory conditions that affect the respiratory system, such as autoimmune diseases.
- Radiation therapy to the neck area.
- A tracheostomy, which is a surgical opening made directly into the trachea.
Key Indicators and Symptoms
The clinical presentation of tracheal stenosis often begins subtly, as the airway narrowing progresses gradually over weeks or months. Patients may initially experience symptoms that mimic common respiratory illnesses, potentially delaying accurate diagnosis. The primary indicator of the condition is stridor, a high-pitched, harsh sound produced during breathing.
Stridor is caused by turbulent airflow attempting to pass through the narrowed upper airway, distinguishing it from the wheezing associated with lower airway conditions like asthma. As the stenosis worsens, the difficulty in breathing, known as dyspnea, becomes more pronounced. Dyspnea is typically worse during physical exertion, as the constricted passage cannot supply the higher volume of air the body demands.
Other common symptoms include a persistent cough and hoarseness, especially if the narrowing is located near the vocal cords. Because the airway is compromised, patients may also experience frequent or recurrent upper respiratory infections.
Confirming the Diagnosis and Treatment Options
Diagnosing tracheal stenosis begins with a detailed medical history, noting any past intubations or neck trauma, followed by a physical examination to listen for stridor. Imaging tests, such as a computed tomography (CT) scan, are used to visualize the airway structure and measure the length and severity of the narrowing. The most definitive diagnostic tool is a flexible or rigid bronchoscopy, where a thin tube with a camera is inserted into the airway. This procedure allows the physician to directly inspect the inner lining of the trachea, assess the extent of the scar tissue, and classify the degree of obstruction.
Treatment is determined by the specific cause, the length of the narrowed segment, and the overall health of the patient. For mild cases where the narrowing is minimal, observation and careful monitoring may be the initial approach.
Interventional Procedures
Interventional bronchoscopic treatments are often used for less extensive scar tissue. While these minimally invasive procedures can offer immediate relief, they are often considered temporary because the scar tissue frequently regrows, leading to recurrence.
- Mechanical or balloon dilation, where an instrument is used to stretch the narrowed section.
- Laser therapy to remove excess scar tissue.
- Placement of a small tube called a stent, which may be temporary or permanent, to hold the airway open.
Surgical Resection
The definitive treatment for longer or more severe segments of stenosis is often tracheal resection and reconstruction. This major surgical procedure involves removing the damaged, narrowed section of the windpipe and sewing the two healthy ends back together. Tracheal resection provides the highest rate of long-term success and is considered a durable solution for suitable patients.