Subglottic stenosis is a narrowing of the airway located just below the vocal cords. This constriction can impede air flow to the lungs, leading to breathing difficulties. The condition can manifest at birth or develop later in life, impacting individuals of all ages.
What is Subglottic Stenosis
Subglottic stenosis refers to a narrowing in the subglottic region, the part of the windpipe (trachea) situated directly beneath the vocal cords and above the main trachea. This area is enclosed by the cricoid cartilage, the only complete ring of cartilage in the airway. When constricted, it acts like a bottleneck, making it harder for air to pass through, similar to trying to breathe through a squeezed straw.
The condition can present in two forms: congenital and acquired. Congenital subglottic stenosis is present at birth. Acquired subglottic stenosis develops after birth due to various factors.
How Subglottic Stenosis Develops
The origins of subglottic stenosis vary depending on whether it is congenital or acquired. Congenital subglottic stenosis results from incomplete or improper formation of the cricoid cartilage during fetal development. The exact reasons for this developmental issue are not fully understood. This leads to an airway that is narrower than typical from birth.
Acquired subglottic stenosis, which is more common, often arises from trauma or medical procedures. A frequent cause is prolonged intubation, where a breathing tube is inserted into the windpipe. The tube’s pressure or movement against the airway can cause injury, leading to scar tissue formation and subsequent narrowing.
Other causes of acquired stenosis include external trauma. Certain systemic or autoimmune conditions can also contribute to its development. For instance, inflammatory conditions like granulomatosis with polyangiitis can lead to scar tissue buildup in the airway. In some cases, the cause remains unknown, a condition referred to as idiopathic subglottic stenosis, observed almost exclusively in women.
Recognizing Subglottic Stenosis
Recognizing subglottic stenosis involves observing specific breathing patterns and other symptoms. A high-pitched whistling noise during breathing, known as stridor, is a common indicator. Stridor from subglottic stenosis is sometimes mistaken for wheezing associated with asthma, which can delay accurate diagnosis.
Individuals may also experience difficulty breathing (dyspnea), which can worsen with physical activity. Other symptoms include hoarseness or changes in voice quality, and a persistent cough. Recurrent episodes of croup, particularly in children, can also suggest subglottic stenosis. The severity of these symptoms can vary widely and may gradually increase over time as the airway narrowing progresses.
Confirming a Diagnosis
Confirming a diagnosis of subglottic stenosis involves an evaluation by medical professionals. The process typically begins with a physical examination and a detailed review of the individual’s medical history and reported symptoms. If subglottic stenosis is suspected, further specialized tests are usually recommended.
Direct visualization of the airway is a key diagnostic method, often performed through procedures like laryngoscopy and bronchoscopy. During these procedures, a flexible or rigid tube with a camera is inserted to directly view the larynx, vocal cords, and the subglottic region, allowing professionals to assess the degree and location of the narrowing.
Imaging techniques such as CT scans of the neck can also be used to visualize the airway’s size. While pulmonary function tests measure airflow and can indicate obstruction, they are generally considered an adjunctive tool rather than a standalone diagnostic method for confirming subglottic stenosis.
Managing Subglottic Stenosis
Managing subglottic stenosis involves various approaches tailored to the condition’s severity, its cause, and the individual’s overall health. For mild cases where airway narrowing is not causing significant symptoms, close observation may be recommended. This involves regular monitoring to ensure the condition does not worsen, especially in children where mild congenital stenosis might improve as the airway grows.
Medical treatments are also used. Steroid injections into the affected area, or corticosteroid pills, may be used to reduce inflammation and scar tissue. These injections can sometimes delay or reduce the need for more invasive procedures. Additionally, managing associated conditions like gastroesophageal reflux disease (GERD) can help prevent further irritation and potential worsening of the stenosis.
When conservative measures are insufficient or the narrowing is more pronounced, surgical interventions become necessary. Endoscopic procedures are often the first line of surgical treatment for less severe cases. These can include endoscopic dilation, where a balloon is inflated to stretch the narrowed segment of the windpipe. Laser surgery may also be used to remove scar tissue and widen the airway. These endoscopic methods are less invasive but may require repeated procedures as scar tissue can regrow.
For more severe or complex cases, open surgical procedures offer more definitive solutions. Laryngotracheal reconstruction (LTR) involves widening the narrowed windpipe with cartilage grafts, while cricotracheal resection (CTR) removes the scarred section and reconnects healthy ends. These open surgeries aim to provide lasting airway widening. In severe airway compromise, a tracheostomy may be performed, creating a surgical opening below the stenosis to bypass the narrowed area. The choice of treatment depends on a detailed assessment of the individual’s condition and needs.