Laryngeal stenosis

Laryngeal stenosis means narrowing of the airway at any level starting from the epiglottis until the trachea. Narrowing at the vocal cords is called glottic stenosis, and one that is just below the vocal cords as subglottic stenosis. The narrowing could be involving one or multiple levels of the larynx.

The glottic web is a membrane of varying thickness and can involve varying length of the vocal cords. Stenosis of the back (posterior) portion of the glottis with or without fixation of the vocal cord joints is called posterior glottic stenosis. Narrowing involving all the levels of the larynx is called transglottic stenosis.

A child could be born with a congenital anomaly of the cricoid cartilage (congenital subglottic stenosis). A very pre mature baby may have predeliction for such a pathology. Frequently, such an infant is intubated for several weeks leading to an acquired form of stenosis (in such a case a mixed form: acquired on a congenital cause). Congenital subglottic stenosis would have the subglottic diameter less than 4.0 mm in a full-term neonate and 3.0 mm in a premature baby.

Accidental strangulation, neck injuries, ingestion of caustic products are some other causes of airway stenosis. There could be an associated stenosis of the pharynx and the esophagus (food pipe).

Stenosis of the larynx will have respiratory and voice complaints. Problems of the posterior glottis affect the respiration. Voice complaints are associated with the anterior glottis. Mild subglottic stenosis may have few symptoms. Moderate narrowing may cause noisy breathing (stridor) and may limit activities as the child gets short of breath. In babies, there may be feeding problems. Severe subglottic stenosis and fusion of the vocal cords require a tracheotomy tube insertion to allow the child to breathe. The voice is usually normal unless the stenosis is very severe or complete.

Children and infants with subglottic stenosis could have other associated problems and comorbidities like complex lung conditions (bronchopulmonary dysplasia), cardiac and neurological conditions, gastroesophageal reflux, swallowing and feeding problems. To get the best results in the treatment of airway stenosis, it is important that all associated problems and comorbidites are treated by a multidisciplinary team. This would allow the best conditions before we correct the airway stenosis. There could be also several syndromes (e.g Trisomy 21 or Downs’s syndrome) which need a holistic broad outook and special care to achieve optimum results.

There is treatment for all kinds of laryngeal stenosis. Broadly, the treatment can be endoscopic or by an external surgery. It is during an endoscopic evaluation that this decision is taken. At times there could be multiple levels of stenosis. In such a case, we can never think of decannulation (removing of tracheostomy canula) if all levels have not been treated optimally.

There are two main operations used to correct subglottic stenosis: laryngotracheal reconstruction (LTR) and cricotracheal resection (CTR). Both these surgeries can be done in one or two stages, and this decision depends on each individual case.

• Laryngotracheal reconstruction (LTR) is an expansion procedure for the airway done by inserting cartilage grafts (harvested from rib, ear or larynx). With time, the expanser cartilage gets integrated into the tracheal and subglottic walls and becomes part of the airway.

  Single-stage LTR in the immediate post operative period will need the child to have a nasal endotracheal tube and admission in the intensive care for 5-7 days. Operations done in 2 stages will have a stent (Monnier’s Laryngotracheal LT Mold) and a tracheostomy. The LT mold is used to calibrate the expanded airway and stabilize the cartilage reconstruction. The LT mold is kept for weeks to months depending on each individual case. It requires a separate endoscopic procedure to remove the stent. The tracheostomy is removed after successful decannulation trials (read below).

• Cricotracheal resection (CTR) is more invasive and technically challenging. It removes (excises) the narrow portion of the airway and then joins the remaining normal diameter of the airway. It is used for more severere type of stenosis.

  The CTR is usually single-stage, but could be in two stages in certain conditions (children with cardiopulmonary and neurological comorbidities). The extended CTR is always in two stages.

A third variety of surgery is the extended CTR which combines the principles of airway expansion with a cartilage graft and cricotracheal resection.

It must be remembered that, it is always a trade-off between the AIRWAY and the VOICE when performing surgical interventions on the airway. Priority is given to decannulation (removal of the tracheostomy canula) which changes the quality of life for the patient and avoids multiple problems associated with the tracheostomy.

The decision of the type of surgery depends on the exact site of stenosis, length of stenosis, involvement of the vocal cords within the stenotic segment and associated comorbidities.

Combined aero-digestive stenosis requires a step-wise management and includes ENT plus pediatric or digestive surgeons.

It is important to note that the best results of airway reconstruction and eventual decannulation (removal of the tracheostomy) lies in the first surgery.

The growth of the trachea is normal and remains unaffected after these interventions. The child has normal development and there is an immense improvement in his quality of life.