Pierre Robin Sequence
The diagnosis of Pierre Robin is made up of three things: a small jaw (micrognathia), enlarged or protruding tongue (glossoptosis), and airway obstruction. The formation of these three things takes place while the baby is still in the womb or uterus. Most of the time a hole in the roof of the mouth (cleft palate) occurs as well and is a 4th sign of Pierre Robin Sequence. In about 4% of Pierre Robin cases a cleft palate does not occur. While the child is still developing the mandible is restricted causing poor growth. This in turn causes the tongue to be pushed upwards in the mouth preventing the roof of the mouth from forming correctly resulting in a cleft palate. The tongue now will be positioned very far in the back of the throat causing problems with breathing and swallowing. This results in what is called obstructive airway disease or obstructive sleep apnea where the child has difficulty breathing while sleeping. The neonate will also have difficulty feeding due to the small jaw and the cleft palate.
Isn’t this Pierre Robin syndrome?
Some people interchange the word “sequence” for “syndrome,” which can lead to some confusion. The simple explanation is that it truly does not matter since people understand what the diagnosis is for the person. The technical term is to use the word sequence since this is a series of events that take place to form the diagnosis we call “Pierre Robin Sequence.”
What is the treatment for Pierre Robin Sequence?
The treatment depends on the severity of the baby’s situation. Some babies can sleep on their stomach to allow the tongue to fall forward to breathe while sleeping then will outgrow the small jaw. This however requires constant monitoring to make sure the baby does not have any issues with breathing or swallowing. Some babies have such severe airway obstruction that intubation is required with a breathing tube placed in the airway to allow for them to breathe. This is typically converted to a more permanent breathing tube called a tracheotomy which is a tube that is inserted through the neck into the airway. Typically it is left in place until the child is old enough to breathe on his or her own.
Recently a new technique has been developed which is called mandibular distraction. This surgery is based on the idea that the main problem is the small jaw that prevents the tongue from moving forward. Therefore if the jaw is advance or moved forward, then the tongue will also move forward and allow the airway to become open. This surgery is done in two stages and involves placing a device that over several weeks stretches the bone to make the jaw larger. The device is removed after 3 months at a second surgery. The biggest benefit is not having to deal with the possible issues and problems with a tracheotomy since a normal airway has been established.
Is my baby a candidate for jaw distraction to enlarge the jaw?
Before a baby is a candidate for mandibular distraction several tests need to be performed to determine if the airway obstruction is truly the cause of breathing in the infant. One of the first tests is a sleep study which monitors the baby while sleeping to determine how often the baby may stop breathing or hold his or her breath. This is done in a carefully monitored environment where the oxygen levels in the baby are continuously checked. Once the sleep study confirms that the baby has obstructive sleep apnea, then a formal examination of the airway must be performed by an Ear-Nose-Throat specialist or otolaryngologist. If the ENT specialist notes that the obstruction is only due to the tongue sitting too far back in the throat, then mandibular distraction can be performed. If the obstruction is due to a lower airway issue such as laryngomalacia or tracheomalacia, then a tracheotomy may be the best option.
What should be done about the cleft palate?
The cleft palate is typically repaired at a later date after surgery. Most plastic and craniofacial surgeons repair the palate at 9 months of age. Some surgeons perform a two stage approach to the palate repair by first repairing the soft palate at 3 months of age then the hard palate at 18 months of age. The theory is that this will allow the soft palate muscles to begin working earlier and allow the hard palate to continue to grow before full speech is developed. If a mandibular distraction is being performed, then a two stage palatoplasty does not add an extra surgery for the child. During the operation to remove the mandibular distraction device, the soft palate can be repaired in what is termed a veloplasty which is the first stage in a 2-stage palatoplasty. In infants who have not undergone mandibular distraction, we typically will wait until they have outgrown their mild obstructive sleep apnea. We rely on sleep studies to determine the severity of the airway obstruction letting us know the best timing for the palatoplasty. Some infants may need to wait until they are over a year old or even close to 2 years old for a cleft palate repair to be performed safely.