What are subglottic hemangiomas?

Hemangiomas are the most common vascular malformation in infants and children. The malformation is composed of capillaries and other small vessels. They may occur anywhere on the body and most appear as solitary skin lesions without involvement if the airway.

Subglottic hemangiomas may form a large mass in the subglottic airway, causing varying degrees of airway obstruction. They grow rapidly for at least 12 to 18 months followed by slow shrinking (called involution). However, not every subglottic hemangioma will shrink completely. Many require active intervention because of their life-threatening nature in the airway.

Testing and diagnosis

Your child will first have a plain neck X-ray, which alone may show a mass. A flexible laryngoscopy in the office may also be enough to reveal a mass. To confirm the diagnosis, a microlaryngoscopy and bronchoscopy will determine the extent of the hemangioma and ensure there is no extension. An MRI of the neck and head might be performed at the same time to ensure the hemangioma has not extended into the neck or skull.

Treatment for subglottic hemangiomas

There are many potential treatments for subglottic hemangiomas, which will depend on the severity of your child's case. A drug called propranolol is rapidly becoming the first-line treatment for severe subglottic hemangiomas.

How propranolol works

Propranolol shows promise in rapid reduction of airway symptoms for children with subglottic hemangiomas. All patients must undergo a cardiac evaluation before beginning this therapy. Propranolol is a beta blocker that causes capillary vasoconstriction, decreased expression of vascular endothelial growth factors, and apoptosis (death) of capillary endothelial cells. This causes the hemangioma to shrink.

The most common side effect of propranolol is drowsiness and hypoglycemia (low blood sugar). For this reason, patients are observed in the Hospital when they start taking the drug, and the dosage is gradually increased to therapeutic levels over several days. This treatment may be supplemented with steroids. Most patients will respond within one to two weeks, but some may not respond at all and require other treatments.

At Children’s Hospital of Philadelphia (CHOP), these children are always followed closely by the vascular malformation team.

Other treatment options

Subglottic hemangiomas can be treated using steroids, tracheostomy, laser, intralesional steroid injections, microdebrider excision, and open surgical excision. These all come with some risk.

• Lasers and microdebridement of the subglottic hemangioma carries the risk of scarring, which may lead to subglottic stenosis.
• Steroids may improve symptoms but put the child at risk of many side effects. Steroid use is only advised for short periods of time.
• Open surgery is a very effective treatment, but is a major operation with some risks. It is usually reserved for cases that fail more conservative approaches.
• Tracheostomy may be used to bypass the airway until the hemangioma shrinks, but comes with risk of mucous plugging, accidental dislodgement, and other life-threatening risks. Furthermore, many hemangiomas may not shrink on their own, requiring further treatment.