Progressnotes - October/November 2012
- About MUSC Health
Every mother listens expectantly for the cry that marks her child’s first breath of life. For a mother of a child with congenital tracheal stenosis, a rare but devastating condition, this moment of joy can turn to horror as her child struggles to catch a breath.
Slide tracheoplasty, a surgical procedure developed in the mid to late 1990s, offers new hope to these children. Two physicians at MUSC Children’s Hospital, David White, M.D., Director of Pediatric Otolaryngology (Figure 1), and Scott Bradley, M.D., Director of Pediatric Cardiac Surgery, have performed about a dozen of these operations, four within the past year, all with a good outcome.
Congenital tracheal stenosis, or narrowing of the windpipe, is typically caused by complete tracheal rings. The normal trachea is characterized by stacked horseshoe-shaped rings with cartilage around three quarters of the trachea and a membrane around the back one quarter, where the trachea shares a common wall with the esophagus. In children with complete tracheal rings, the cartilage extends around the entire trachea, making it narrower and less flexible. As a result, these children have difficulty breathing and can present with stridor (noisy breathing), coughing and even cyanosis. Without treatment, the condition is often fatal.
Of the children with congenital tracheal stenosis, about one third require emergent surgical intervention in the first week of life to establish sufficient air flow, about one third require surgery within the first month or two of life, and the final third show symptoms, usually exercise-induced, only when older (two to three years old). Eventually, almost all children with this condition will require surgery.
Until the introduction of slide tracheoplasty, the prognosis of children with the more severe form of tracheal stenosis was poor, with 50% or more dying of complications from available surgical interventions. In contrast, morbidity and mortality are lower than 5% to 10% in patients who undergo slide tracheoplasty, a procedure in which the narrow part of the trachea is cut in half, incisions are made in both directions from that point, and the two halves of the trachea are slid over each other, making the trachea shorter but wider. The procedure must be done on cardiopulmonary bypass to oxygenate the blood while the trachea is repaired. According to Dr. Bradley, the surgery is particularly challenging “because of the surgical approach required and because of the small size of the trachea in very small babies.”
Good outcomes with this complicated but life-saving procedure require the resources of a pediatric academic medical center with a multidisciplinary team of experts experienced in this procedure. MUSC Children’s Hospital, one of the few institutions in the country with the specialized diagnostic, surgical and anesthetic equipment, surgical expertise and auxiliary support needed for this challenging procedure all in one place, serves as a regional center for this procedure.
It offers a wide variety of pediatric medical specialists and allied personnel (eg, pediatric respiratory therapists, child life specialists), who have decades of combined experience in treating children and who collaborate closely to provide the best possible care.
“What you get when you come to a dedicated pediatric facility are people with specific, advanced and dedicated training—typically many years in length—and expertise in the care of both healthy and very complicated sick children. You also benefit from the fact that their focus, interest and commitment are directed completely toward the care of children,” notes Francis X. McGowan, Jr, M.D., Professor of Anesthesiology and Pediatrics and Chief of Pediatric Anesthesia at MUSC Children’s Hospital.
The diagnostic expertise of pediatric specialists is key to recognizing congenital tracheal stenosis. Diagnosing tracheal stenosis can be difficult because the associated stridor, coughing and other breathing difficulties can also be symptomatic of many other childhood illnesses. At MUSC, Anthony M. Hlavacek, M.D., Associate Professor of Pediatric Cardiology, uses cardiac computed tomography (CT) (Figure 2) to noninvasively visualize the airway for the slide tracheoplasty team a day or two in advance of the surgery, establishing the diagnosis and allowing the team to better plan the operation. Dr. Hlavacek and his team adjust the CT scanner to the lowest dose necessary to produce a diagnostic image, usually less than is present in background solar radiation, minimizing radiation risk to children. These CT findings are confirmed immediately before the operation with a bronchoscopy performed by Dr. White.
In the one third of newborns with tracheal stenosis who require emergent care to survive, proper oxygenation must be ensured while the slide tracheoplasty team is assembled. At MUSC, pediatric surgeons, under the leadership of Dr. André Hebra, Chief of Surgery for MUSC Children’s Hospital, place these children on extracorporeal membrane oxygenation (ECMO), which provides cardiac and respiratory support prior to the operation (Figure 2).
The successful outcomes achieved by the slide tracheoplasty team at MUSC hinge on the close collaboration among its members. According to Dr. McGowan, the operation “requires not only knowledge and technical skills but also awareness of what your partners are doing and constant communication with them at each stage in the dance.”
Leading the dance are Dr. White, an ear nose and throat (ENT) specialist, and Dr. Bradley, a cardiothoracic surgeon. Dr. White establishes the diagnosis via review of the CT scans and bronchoscopic findings, assesses and manages the difficult airway and plans the operation. Dr. Bradley places the child on cardiopulmonary bypass and collaborates on the actual procedure. A top-notch pediatric perfusionist is needed to ensure proper gas exchange via cardiopulmonary bypass while the trachea is reconstructed. In children, especially in children with difficult airways such as those with tracheal stenosis, the airway is jointly managed by the surgical specialists and the pediatric anesthesiologist. Together, they ensure an adequate airway during induction of anesthesia, while the child is being placed on and removed from cardiopulmonary bypass and in the pediatric cardiac intensive care unit (PCICU), where they are assisted by experienced pediatric nurses and respiratory therapists.
The ENT specialist is responsible for follow-up of these children, who will require additional bronchoscopies to look for excessive scar tissue and to ensure that the airway grows properly with the child. For most children, only a single operation is required. In a few cases, further surgical revision has been necessary, but with the combined expertise of MUSC’s dedicated pediatric specialists, trained in the management of difficult pediatric airways and experienced in the procedure, the outcomes of these revisions have been excellent.
With the advent of slide tracheoplasty, tracheal stenosis in children, once deadly, has become a correctable condition. Because the depth of resources needed to treat these children is available in so few institutions, physicians should consider referring children with persistently difficult airways, particularly those who have been confined to a ventilator, to an ENT specialist at a dedicated pediatric facility for diagnostic bronchoscopy.
With slide tracheoplasty, not only children with tracheal stenosis but also their parents can once again breathe easily.
This article originally appeared in the April/May 2012 issue of Progressnotes.