Introduction
Tracheal stenosis is a rare malformation causing partial airway obstruction and respiratory insufficiency. Tracheal stenosis occurs due to either injury (acquired tracheal stenosis) or birth defect (congenital tracheal stenosis). Congenital tracheal stenosis (CTS) causes breathing difficulties in children and often requires surgical correction.
What Is Trachea?
The trachea, or the windpipe, is a long tube about 4 inches long and less than one inch in diameter. The tube begins from the bottom of the larynx(voice box) and extends to the lungs. It transports air from and to the lungs.
What Is Congenital Tracheal Stenosis?
Congenital tracheal stenosis is a rare, life-threatening defect present at the time of birth. It leads to symptomatic airway obstruction and breathing difficulties in children because the trachea's cartilage support structure causes the airway's narrowing. It often occurs associated with cardiac abnormalities. The most common cardiac defect associated with congenital tracheal stenosis is pulmonary artery sling(PAS). Congenital tracheal stenosis usually manifests in the neonatal period or infancy. It is seen in 1 out of 64,500 cases. The exact cause of congenital tracheal stenosis is unknown.
What Is the Pathophysiology of Congenital Tracheal Stenosis?
Congenital tracheal stenosis occurs due to embryogenesis defects after the 8th week of gestation. The normal tracheal cartilage is C-shaped, and the back wall of the trachea is softer with muscles that allow the trachea to expand during breathing. In congenital tracheal stenosis, complete cartilaginous tracheal rings are present without the membranous portion due to the defect in embryogenesis. So the tracheal lumen is reduced in diameter to 2 to 3mm, causing an obstruction. The tracheal rings become prone to crusting.
What Are the Types of Congenital Tracheal Stenosis?
Cantrell and Guild have categorized congenital tracheal stenosis into three types. They are:
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Generalized stenosis.
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Funnel-like stenosis.
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Segmental stenosis.
What Are the Symptoms of Congenital Tracheal Stenosis?
The symptoms of congenital tracheal stenosis are noticed shortly after birth. The affected infants and children show signs in the respiratory tract. The symptoms include the following:
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Breathing difficulties.
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Stridor (abnormal breathing sound).
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Recurring pneumonia(inflammatory condition of the lungs).
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Wheezing.
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Cyanosis (bluish-purple skin discoloration due to insufficient oxygenation of the blood).
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Chest congestion.
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Persistent cough.
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Apnea(temporal cessation of breathing).
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Respiratory insufficiency.
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Infants have difficulty in breastfeeding or bottle feeding.
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Children may choke after eating.
Affected patients are divided into three groups based on their symptoms. They are:
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Patients with minimal or no respiratory symptoms.
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Patients with respiratory symptoms in the neonatal period.
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Patients with respiratory symptoms in late infancy.
When to Suspect Congenital Tracheal Stenosis?
Congenital tracheal stenosis may be suspected in the following circumstances:
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When a child has difficulties in breathing or noisy breathing after birth.
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If an airway malformation is detected during pregnancy by ultrasound and fetal magnetic resonance imaging (MRI).
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When the child has respiratory symptoms like asthma but not responding to asthma treatment.
How to Diagnose Congenital Tracheal Stenosis?
Congenital tracheal stenosis is identified immediately after birth or during earlier childhood. Healthcare providers perform standard diagnostic procedures in the intensive care unit under anesthesia. The diagnostic procedures include:
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Bronchoscopy - The healthcare provider inserts a thin, bendable tube into the mouth and passes it down into the trachea to examine the trachea functions and to detect any narrowing of the windpipe.
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Microlaryngoscopy - It is performed with a small rigid metal tube called a laryngoscope inserted into the nose and down into the trachea to measure the narrowing of the windpipe to determine the specific treatment.
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Computed Tomography(CT) Scan - Helps direct the windpipe's narrowing.
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Fetal Ultrasound - Shows blood vessel abnormalities such as pulmonary artery sling, usually associated with congenital tracheal stenosis.
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Pulmonary Function Test - To examine the response of the trachea when the patient is in an active state.
What Is the Treatment for Congenital Tracheal stenosis?
The treatment of congenital tracheal stenosis often requires surgical correction. The treatment options depend on the disease's severity, the child's age and weight, the extent of the stenosis, and associated cardiac abnormalities. The treatment options are:
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For children with congenital tracheal stenosis breathing well on their own, the healthcare team follows and ensures the airway's growth as the children age.
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For children with breathing difficulties, initial control of the airway is essential. It is achieved with intubation or mechanical ventilation.
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If adequate oxygenation is absent, extracorporeal membrane oxygenation(ECMO) and intraluminal tracheal stenting(to keep the trachea open temporarily) are used.
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Surgical resection or reconstruction of the trachea is the most effective type of management. The common open surgical procedures are:
- Slide Tracheoplasty - This is a complex procedure to make the airway larger. The narrowed trachea is divided across the area where it is narrowed. A smaller portion of the upper and lower tracheal segments are cut and reattached, providing a wider airway but a little shorter than before. This technique can be modified for the treatment of bronchial stenosis and other tracheal malformations.
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Laryngotracheoplasty - It is used to treat tracheal stenosis or subglottic stenosis. The narrowed diameter of the trachea is enlarged by inserting a piece of cartilage. The cartilage can be taken from the child’s rib or ear. It depends on the size of the cartilage needed to enlarge the trachea.
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Cricotracheal Resection - This procedure involves the removal of scar tissue and ring-shaped cartilage of the larynx. Then the normal trachea is brought up to replace it.
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Segmental Tracheal Resection - this procedure involves the removal of defective segments of the trachea, and the remaining ends of the trachea are sutured back to repair the airway.
Conclusion
Children with heart and lung abnormalities and genetic diseases such as Down syndrome are at a higher risk of having congenital tracheal stenosis. Management of patients with congenital tracheal stenosis is complex, requiring a multidisciplinary team including pediatricians, anesthesiologists, surgeons, and nursing staff. Each surgery has a different recovery time. Post-surgical care and follow-up after the surgery are important for the betterment of the children.
