A surgical paradigm shift makes it possible for kids with severely restricted airways to breathe on their own.
A new surgical approach for Treacher Collins syndrome redefines it as a rotation deformity of the entire face and not a lower jaw issue. It’s a paradigm shift that is changing the current standard of care and allowing children who have the most severe form of the syndrome to breathe normally after having lived with tracheostomies since birth.
Dr. Richard Hopper, surgical director of Seattle Children’s Craniofacial Center and chief of the Division of Plastic Surgery, developed the new procedure with his team (including craniofacial orthodontist Dr. Hitesh Kapadia) out of sheer necessity. By coincidence, they saw two patients with a very rare type of craniofacial microsomia (characterized by an abnormally small jaw) who could no longer be supported for tracheostomy and had to have their breathing tubes taken out.
“When we were puzzling over the kids with craniofacial macrosomia, we had an aha! moment,” explains Hopper. “We realized that their entire faces were rotated backwards, squishing the entire upper airway. That led to the question, how do we unrotate the face?”
The surgery (called subcranial rotation distraction) was so successful that, with a few modifications, they knew it could also help children with the most severe form of Treacher Collins syndrome, a rare genetic condition that affects fetal development of the bones, jaw, skin and facial muscles. Babies born with the condition typically have problems breathing, chewing, swallowing, hearing and speaking. In the most severe form, with underdeveloped or missing facial bones restricting their airway, this causes life-threatening respiratory problems and creates the need for a tracheostomy.
To date, four children have had completely normal sleep studies after undergoing the yearlong three-surgery procedure that takes distraction osteogenesis – a way to lengthen a bone – to a new level.
Rethinking the status quo
For the last two decades, the standard treatment for a patient with Treacher Collins with a tracheostomy was to lengthen the lower jaw – a treatment designed to create more space for the tongue so it wasn’t pushing against the throat and blocking the airway. But success rates for the isolated jaw surgery were extremely low, as were other airway surgeries done on the inside of the nose and mouth to try to make breathing better.
Hopper says the airway is like a narrow tunnel and treatments in the past have only been able to remove single speed bumps within the tunnel, so air still gets held up. “Subcranial rotation distraction takes the whole roof of the tunnel and opens it. The surgery rotates the entire face in a new location on the foundation of the skull base – and the airway improvement is like nothing anyone has ever seen before.”
A game-changing process
The three-surgery procedure, typically performed on children age 9 and older after the upper part of their face is finished growing, is one of the most all-encompassing at Seattle Children’s Craniofacial Center: over the course of the treatment phases, it involves more than 40 clinicians from 18 different disciplines. Children undergoing the surgery must have breathing and feeding tubes in throughout the yearlong process.
“The airway improvement is like nothing anyone has ever seen before.” – Dr. Richard Hopper
During the first, and most complex, surgery, Hopper begins with an osteotomy (cut in a bone) to separate the child’s entire face from its attachments at the skull base – a technique that makes the entire face loose and able to move as one single piece. Then, he wires the upper and lower jaws shut and creates a metal hinge at the top of the nose that allows a brace called a midface distraction device (in concert with paired mandible distraction devices) to swing the entire face forward in the weeks after surgery. This movement unlocks the breathing space behind the jaws and nose. A U-shaped distractor wraps around the sides of the child’s head and attaches to the skull with special screws and to the lower jaw with pins that pass across the face in front of the spinal cord.
Once the surgery is complete, the devices are activated at a slow rate to gently rotate the child’s face into its new position over a month’s time. Since the child is an outpatient (but remains close to the hospital during this phase), a parent or caregiver uses a special tool to turn the distractor one to two millimeters a day – much like tightening braces on teeth. The daily turning keeps tension on the distractor and very gradually moves the cuts in the jaw bones apart. A taffylike substance called generative tissue forms in the gaps between the face and the skull base. Once Hopper determines that the bones are in the right position, the turning stops and the generative tissue begins to turn to hardened bone, forming a longer lower jaw and a newly positioned upper jaw.
The second surgery is a quick day surgery to release the wires locking the child’s jaw so they can open and close their mouth. At this point, the child goes home still wearing the distractor so that the bones can consolidate fully over a period of two to three months.
Hopper credits the entire craniofacial team as the reason patients and families have been successful during the distraction period. Bay Sittler, a nurse practitioner in the Craniofacial Center, is heavily involved with children undergoing distraction. “This is a huge marathon for a child and their family with different phases. Bay is always there, making sure they’re getting all the care they need and helping avoid all the potential pitfalls. We couldn’t do this without her.”
In the third and final surgery, Hopper and his team take off the distractor, and use bone grafts from the child’s skull to build cheek bones to protect their eyes. During the next three months, the child’s parent or caregiver slowly gets the child used to breathing through their nose and mouth by partially capping their breathing tube. Once the child is able to sleep with their breathing tube completely blocked, they have a sleep study. If it’s normal, the final step is to permanently remove the tracheostomy.
Evidence advances care
Hopper is tracking outcomes of the procedure until his patients finish growing in their mid-to-late teens.
“The old standard of care has a very high relapse rate within a year or two because the lower jaw can’t hold the strain of the entire face,” he says. “Our approach gives much greater stability to the normal tension of the face, because everything is moving together and the entire face is reset to a new normal position. Sometime in the next five years or so, the burden of evidence will become high enough that craniofacial centers around the country and across the world will choose subcranial rotation distraction as the new standard of care.”
Note as of August 2018
Subcranial rotation distraction is now known as counterclockwise craniofacial distraction osteogenesis (C3DO). Read more in Plastic and Reconstructive Surgery, Journal of the American Society of Plastic Surgeons.