The diameter of a normal newborn subglottis is 4 mm. If the subglottis is less than 3.5 mm, it is considered narrow.
What is Subglottic Stenosis?
Subglottic stenosis is a narrowing of the airway in the part of the voice box below the vocal cords (glottis). The diameter of a normal newborn subglottis is 4 mm. If the subglottis is less than 3.5 mm, it is considered narrow. There are two kinds of Subglottic Stenosis:
- Congenital Subglottic Stenosis - A child is born with a smaller than normal airway. This occurs when the airway did not form normally before birth.
- Acquired Subglottic Stenosis - This type is not present at birth, but develops after birth. This most commonly occurs due to infection, trauma, or problems associated with intubation (a breathing tube inserted into the airway). These issues can cause scar to form in the airway that causes narrowing.
What Are the Signs and Symptoms of Subglottic Stenosis?
- High pitched noisy breathing (stridor) that occurs when your child breathes both in and out. This can worsen when your child is ill or after exercise or strenuous activity.
- At times, children have been diagnosed with multiple episodes of croup at a young age.
- Poor weight gain
- Increased effort to breathe with pulling in the neck, between or under the ribs
How is Subglottic Stenosis Diagnosed?
Tracheomalacia can be suspected based on history and physical exam. It can sometimes be seen with certain types of X-rays, including CT scan of the Chest or Airway Fluoroscopy. Diagnosis is confirmed with Direct Laryngoscopy/ Bronchoscopy. In addition to making a diagnosis, a laryngoscopy and bronchoscopy allows your doctors to grade how severe the narrowing of the airway is. In many cases, significant symptoms do not develop until the airway is more than 50-60% smaller than normal size.
How is Subglottic Stenosis Treated?
Treatment depends upon the severity of narrowing and the associated symptoms. In some cases, only supportive care and monitoring is needed. Sometimes the airway can be dilated (widened) with a balloon. For more severe problems, a surgical procedure to expand the airway, either through telescopes, or through an incision in the neck, is recommended. Often expanding the airway involves taking a piece of cartilage from another location and using it to expand the size of the airway. In rare instances, the narrowing is so severe that a tracheotomy needs to be placed to bypass the obstruction before a reconstructive surgery can take place.
The Pediatric Otolaryngologists at Nationwide Children’s have undergone additional training in pediatric airway management and will discuss all surgical and nonsurgical options with you prior to making a recommendation for treatment.
When Should I Be Concerned If My Child Has Subglottic Stenosis?
It can be difficult for a parent or family member to discern the severity of a breathing problem when a child has subglottic stenosis. If you are concerned, we urge you to seek medical evaluation immediately. If your child is showing signs of illness, consider consulting your physician for additional treatment recommendations, as this may result in severe symptoms.
In particular, signs that indicate more severe conditions include: irritability, poor feeding, pulling in of the skin at the collar bone, between the ribs, or under the ribs, flaring of the nose, increasing effort to breathe, and poor weight gain or weight loss, especially in infants.
Symptoms that should trigger emergent evaluation include: pauses in the breathing, color change of the skin (particularly if the lips, face, or hands are turning blue), appearing lethargic or tired, or any other sudden change from a child’s normal breathing pattern. If any of these or other concerning signs develop, please seek immediate medical attention.