TORONTO-There is an increased awareness of sleep-disordered breathing in children, but even after tonsillectomy and adenoidectomy (T&A), between 5% and 10% of all cases have persistent obstructive sleep apnea (OSA). An expert panel at the annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) addressed various diagnostic, surgical, and therapeutic approaches that can be used to treat these patients.
The number of children who are being treated for sleep apnea in the country tends to be a fairly significant percentage or proportion of children, said panel moderator Peter Koltai, MD, Chair of Pediatric Otolaryngology at Stanford University.
There are many reasons for OSA treatment failure, including neuromuscular problems, craniofacial abnormalities, and problems with dental and occlusal mouth proportions, as well as special concerns such as primary macroglossia among the Down syndrome and other populations. In addition, there can be lingual tonsil hypertrophy (LTH) following T&A.
When it comes to diagnosis, its key to determine whether the child snores-though in some cases a child may have apnea yet not snore, according to Norman Friedman, MD, director of the pediatric pulmonary sleep lab at the University of Colorado. Children who don’t snore either have a neuromuscular disorder, or some palatal modification, he said.
Obesity represents the biggest predictor of persistent apnea postoperatively. Black race and family history of sleep disorder breathing are also predictors, along with presence of lingual tonsils.
To make the diagnosis, you want to be a good detective, Dr. Friedman said. Get a sleep study along with an EEG to determine whether REM sleep is achieved, and perform airflow and gas exchange studies.
Children who should get a postoperative sleep study include those with persistent symptoms, children with neuromuscular disorders, syndromic children, those who had severe OSA preoperatively, and those who underwent palatal modification. Children who are going to be treated with continuous positive airway pressure (CPAP) need a sleep study too, Dr. Friedman said.
Diagnostic tools can include flexible endoscopy, fluoroscopy, cine MRI, and lateral neck radiographs. Cephalometry reveals additional anatomy, including maxillary and mandibular deficiencies.
CPAP in Pediatric OSA Patients
On another note, CPAP is becoming more recognized as an option for treating children with persistent OSA-although it is not FDA-approved for children (its use is off-label) and many insurers won’t cover it, said John Houck, MD, from the University of Oklahoma.
We need to know, as otolaryngologists, what’s involved in CPAP, what are the problems, and what is the state of the art, he said. Most published studies in this area are case series, so the evidence is weak.
Studies suggest that child-sized masks work well, although custom masks are needed for children with craniofacial deformities. To determine which pressure works for a patients means having to do a CPAP titration.
A significant issue with CPAP is getting kids enthused about it and getting parents onboard. With good compliance, CPAP in kids is reportedly 86% effective.
CPAP is effective, it’s safe. You need extensive parental involvement. And it’s a reasonable alternative in difficult patients, Dr. Houck said.
Oral Appliances for OSA Children
For OSA due to orofacial causes, oral appliances may be useful, said David H. Darrow, MD, DDS, from the departments of otolaryngology and pediatrics at Eastern Virginia Medical School.
The two main groups of candidates for oral appliance therapy are long face and small jaw patients. Those with a long face have a long, lower anterior face, a steep mandibular plane, high arched palate, or narrow maxilla. A small jaw patient has a retruded mandible or short ramus.
Oral appliances are designed to increase the space available for respiration, whether it’s trying to affect the nose or trying to affect the oral cavity or pharynx, he said.
There are three main types of devices. One type is the maxillary expander, which increases the transverse dimension of the patale and expands the intranasal space. Studies show that these devices improve nasal resistance, as well as tongue position. Maxillary expanders need to be anchored to the first permanent molars.
The second group include mandibular repositioners and tongue retention devices, which are designed to position the tongue more anteriorly. Mandibular advancement devices are appliances that move the jaw forward and bring the tongue along with them passively. The idea is to increase the anteroposterior diameter of retroglossal space, Dr. Darrow said.
Children should be selected for mandibular repositioning carefully, Dr. Darrow said. Some tolerate the device poorly. Also, children with severe obstruction get only a small improvement in OSA. If they’re severely obstructed you should probably be looking at other solutions, he said.
Tongue retention devices use a suction bulb to hold the tongue forward, but are too uncomfortable for children.
The third type of device is the palatal lift device, designed to elevate the soft palate away from the tongue base. These devices are not very effective for OSA.
Data from a recent Cochrane Review suggest that CPAP is often more effective than oral devices. The problem is that CPAP is often poorly tolerated, so oral devices should be considered sort of a backup device for patients who may not tolerate CPAP, Dr. Darrow said.
Surgery is often an option for persistent OSA, but in addition to soft tissue obstruction the bony facial skeleton must be into account, said James Sidman, MD, from the Children’s Hospital-Minneapolis. Yet, working on bone in children is fraught with difficulties, in part because children are growing.
Mandibular surgery in very young children is very effective and has few long-term complications and numerous long-term benefits. However, the effectiveness of maxillary distraction is still unknown.
Mandibular distraction is done primarily for micrognathic children, although not all micrognathic children have Pierre-Robin sequence-some may have Treacher-Collins or other syndromes.
We begin distraction after three to five days.…If it’s an older child who is already trached or has a safe airway, then we can send them home on post-op day two or three, Dr. Sidman said. Distraction is done twice a day at about three-quarters of a millimeter. The parents can do the linear distraction and the otolaryngologist does the nonlinear distraction.
External distractors leave small marks on the side of the face, but there is no significant scarring, Dr. Sidman said. The procedure can be done in children as small as 2 or 3 kg.
Midface distractions are for nasal and nasopharyngeal obstruction, but there must be adequate bone stock, and the child should be at least 4 years old.
Models help with surgical planning. The models are plastic and based on the patient’s CT scans. We use models of the facial skeleton that we operate on beforehand, and put the distractors on the models, so we have our vectors exactly planned before we operate, Dr. Sidman said.
The maxillary procedure is generally reserved for children who can’t tolerate CPAP or BiPAP, who have severe obstruction as seen through endoscopy. However, the operation is not proven long-term and there is significant relapse when there is insufficient bone stock.
Once you’ve done the distraction, consider going in and putting in either absorbable plates or long-term titanium plates to try to help hold the regenerate in position long-term, he said.
Obstruction at the Tongue Base
Obstruction at the base of the tongue is another important cause of persistent apnea. This was addressed by Sally Shott, MD, from the Cincinnati Children’s Hospital Medical Center, who described surgical interventions.
After T&A, the incidence of persistent OSA is higher in the Down syndrome population. The tongue is involved in the highest percentage-macroglossia, glossoptosis, and also enlarged lingual tonsils, she said.
Traditional surgical options included resection of a wedge at the base of the tongue. The problem with this surgery is it hurts a lot and recovery is protracted, Dr. Shott said.
Radiofrequency (RF) ablation reduction to the base of the tongue is another option for treating glossoptosis and macroglossia. In adults, initial studies showed RF reduction resulted in a 55% reduction in the RDI.
Dr. Shott’s experience, however, has shown that RF reduction is usually not enough. I more commonly use this in addition to other procedures on the base of the tongue, she said.
With the midline osteotomy genioglossus advancement the intent is to take a segment of the midline mandible with attached genioglossus muscle, and pull it forward.
The problem is that in children it’s limited in that they have to have their secondary dentition in. I don’t feel it gives enough pull to the base of the tongue, particularly in children who have a lot of hypotonia, she said.
An alternative version of the technique is the Repose genioglossus advancement. A permanent suture is anchored at the genial tubercle with a 3-mm titanium screw. The suture is passed in a triangular fashion through the base of the tongue and posterior to the circumvallate papillae, and a small titanium screw is attached. It is done via a submental incision and initial results have been good.
A newer procedure is the submucosal minimally invasive lingual excision (SMILE). Through a midline dorsum incision on the dorsum, 2 cm from the tongue tip, submucosal removal of tomgue muscle is done using the Coblater II Surgery system.
The surgery is done medial to the lingual arteries, which can be identified with ultrasound, which lowers the risk of hypoglossal nerve injury. The procedure is apparently associated with less postoperative pain. However, its use has been reported on only four patients.
Dr. Koltai discussed some of the challenges with the rarely performed lingual tonsillectomy.
Lingual tonsil hypertrophy (LTH) is not very common. On the other hand, airway obstruction secondary to lingual tonsil hypertrophy is well recognized, he said.
It usually presents as sleep-disordered breathing and in Down syndrome. To do lingual tonsillectomy, children need to undergo nasotracheal intubation.
Especially challenging cases are post-T&A cases with no obvious lateral lingual tonsil hypertrophy, or cases with no previous T&A and no anatomical cause.
The two most important diagnostic tools for this are the office fiberoptic laryngoscopy and sleep endoscopy. The latter is done under a light general anesthesia where the child is spontaneously breathing in a recumbent position.
What is seen is a large pad of lingual tonsil along with glossoptosis, forcing the epiglottis up against the posterior pharyngeal wall. The indications for lingual tonsillectomy would include a high RDI and oxygen desaturations and a dynamic confirmation of LTH.
The only tool that I’ve found that’s consistently effective for this is the coblator, Dr. Koltai said. The volume of the tongue can be effectively reduced with no bleeding. RDI is improved with the operation, but it’s hard to get it under 5.
©2007 The Triological SocietyMulti-Page