Sleep apnea is a respiratory dysfunction that results in a cessation or near cessation of respiration for a minimum of 10 seconds. Sleep apnea syndromes are classified as dyssomnias and include central, obstructive, or mixed apnea. Central sleep apnea is defined as a neurologic condition causing cessation of all respiratory effort during sleep. Usually, there is no mechanical obstruction associated with central sleep apnea. Obstructive sleep apnea (OSA) occurs when respiratory effort is present with the temporary collapse and obstruction of the upper airway; it is characterized by repetitive pauses in breathing. Mixed sleep apnea is a combination of central sleep apnea and OSA, with the central apneic element usually presenting prior to the obstructive apneic component. Undiagnosed and untreated individuals have repeated apneic episodes during the night, causing pronounced disruption of their sleep cycles and various daytime symptomatology.
OSA is commonly associated with airway obstruction caused by one or more of the following:
- Obesity
- Specific anatomic abnormalities of the upper airway such as, but not limited to, enlarged tonsils, enlarged adenoids, an enlarged tongue, and small jaw structure
- Retropalatal/retrolingual obstruction, adenotonsillar hypertrophy, mandibular deficiency, or macroglossia
- Upper airway tumor
- Excessive pressure across the collapsible segment of the upper airway
- Insufficient activity of the muscles of the upper airway to maintain patency
Symptoms of OSA may include, but are not limited to, the following:
- Snoring
- Morning headache
- Excessive daytime sleepiness (not explained by other factors)
- Choking or gasping during sleep
- Recurrent awakenings from sleep
- Fatigue and impaired concentration
OSA occurs most often in moderately to severely obese individuals and affects more men than women. Complications may include cardiac rhythm disturbances and hypertension. The mortality rate from stroke and myocardial infarction is significantly higher in individuals with OSA than in the general population. For obesity-related sleep apnea, weight loss often reduces obstructive apneic episodes, improves blood gases, and lessens daytime drowsiness.
The diagnosis of OSA is made by evaluating an individual’s symptoms and measuring physiological parameters during sleep, called sleep testing. Sleep testing is classified as follows:
- Type I: A sleep study performed in a facility that measures electroencephalogram (EEG), electrooculogram (EOG), electrocardiogram (EKG), electromyogram (EMG), oxygen saturation, respiratory effort, and airflow.
- Type II: A sleep study performed with portable equipment that measures a minimum of 7 channels (including EEG, EOG, EMG, ECG/heart rate, airflow, respiratory effort and oxygen saturation).
- Type III: An unattended sleep study performed with portable equipment that measures a minimum of four simultaneous and continuous recording channels (including oxygen saturation, respiratory movement, airflow, and EKG/heart rate).
- Type IV: An unattended sleep study performed with portable equipment that measures three or more physiological parameters, one of which is airflow.
- Sleep testing devices that measure three or more channels that include actigraphy (measurement of movement), oximetry (oxygen saturation), and peripheral arterial tone (pulsatile volume changes) when used to aid in the diagnosis of OSA.
The apnea hypopnea index (AHI) and respiratory disturbance index (RDI) are considered diagnostic for mild OSA if more than five and less than 15 observed apneas or hypopneas occur per hour of sleep. The AHI is equal to the average number of episodes of apnea and hypopnea per hour. The RDI is equal to the average number of respiratory disturbances per hour. Moderate-to-severe sleep apnea is generally defined as an AHI or RDI greater than or equal to 15 events an hour, or an AHI greater than five and less than or equal to 14 events per hour with additional symptoms (e.g., excessive daytime sleepiness, insomnia, mood disorders, hypertension). Individuals with severe OSA have more than 30 events recorded per hour of sleep.
PRIMARY SNORING
Primary snoring (also known as simple snoring, noisy breathing during sleep, snoring without sleep apnea, benign snoring, rhythmical snoring, and continuous snoring) is characterized by loud upper airway breathing sounds in sleep without episodes of apnea. Although snoring is a sign of upper airway obstruction during sleep, testing may determine that there are no indications of reduced airflow or other signs of sleep apnea. When no clinically significant underlying pathology is found, these individuals may be diagnosed with primary snoring.
TREATMENT OF OSA
OSA is chronic and relapsing; therefore, multiple therapeutic approaches may be necessary. Treatment options for mild-to-moderate OSA include:
- Weight reduction
- Sleep position training
- Oral appliances designed to keep the tongue and jaw forward
- Nasal continuous positive airway pressure (CPAP)
- Medications (i.e., medroxyprogesterone acetate, protriptyline), indicated for a small number of individuals who satisfy specific criteria
- A variety of surgical procedures
CONTINUOUS POSITIVE AIRWAY PRESSURE (CPAP), AUTO-ADJUSTING CONTINUOUS POSITIVE AIRWAY PRESSURE (CPAP), AND BI-LEVEL (INTERMITTENT) POSITIVE AIRWAY PRESSURE
The recommended initial treatment for individuals diagnosed with mild OSA with certain co-morbidities, moderate OSA, or severe OSA is a trial of CPAP. CPAP is a noninvasive technique that prevents upper airway occlusion by splinting the pharyngeal airway with low levels of positive pressure delivered through the nares via a nasal mask. The purpose is to prevent the collapse of the oropharyngeal walls and the obstruction of airflow during sleep. Auto-adjusting CPAP automatically adjusts the level of air pressure for each breath taken based on the level of resistance. Bi-level positive airway pressure also delivers continuous pressure and allows the pressure to be adjusted separately during inspiration and expiration. The device cycles between a predetermined inspiratory PAP phase and a preset expiratory PAP phase.
ORAL APPLIANCES
Oral appliances are used for:
- Individuals diagnosed with primary snoring and/or mild OSA who do not respond to or are not appropriate candidates for behavioral measures such as weight loss or sleep position training
- Individuals with OSA who refuse or do not respond to nasal CPAP or auto-adjusting CPAP
- Individuals who refuse or are not candidates for surgical interventions
The effectiveness of the oral appliance is determined by its ability to advance the mandible in a vertical and sagittal plane. Appliances that are custom made and adjustable have been found to be more effective than fixed, thermoplastic-type appliances. In general, prefabricated devices are not effective. It has been shown that tongue retaining and other inactive devices do not improve AHI, oxygen saturation, Epworth Sleepiness Scale, or blood pressure.
A custom-fabricated oral appliance is one which is individually and uniquely made for a specific individual. It involves taking an impression of the individual’s teeth and making a positive model of plaster or equivalent material. Custom fabrication requires more than trimming, bending, or making other modifications to a substantially prefabricated item. A-custom fabricated oral appliance may include a prefabricated component (e.g., the joint mechanism).
A custom-fabricated mandibular advancement device incorporates all of the below:
- A fixed mechanical hinge at the sides, front, or palate. A fixed hinge is defined as a mechanical joint, containing an inseparable pivot point. Interlocking flanges, tongue and groove mechanisms, hook and loop or hook and eye clasps, elastic straps or bands, etc, (not all-inclusive) do not meet this requirement.
- Capability to protrude the individual's mandible beyond the front teeth when adjusted to maximum protrusion.
- Incorporates a mechanism that allows the mandible to be easily advanced by the individual in increments of one millimeter or less.
- Retains the adjustment setting when removed from the mouth.
- Maintains the adjusted mouth position during sleep.
- Remains fixed in place during sleep to prevent dislodging the device.
- Requires no return visits beyond the initial 90-day fitting and adjustment period to perform ongoing modification and adjustments in order to maintain effectiveness.
In October 2020, the FDA gave 510(k) approval to the Slow Wave DS8, an intra-oral device intended to reduce or alleviate snoring and mild to moderate Obstructive Sleep Apnea while sleeping in adults. This mandibular repositioning device acts to increase the users’ pharyngeal space and improves their ability to exchange air during sleep. The device consists of two separate trays worn on the maxilla and mandible and it does not incorporate a mechanical hinge. The DS8 allows the user to open and close their jaw when asleep and provides full lateral movement of the mandible. This custom fabricated oral device is created from a digital intraoral scan and is 3D digitally printed in a lab.
The US Food and Drug Administration (FDA) has approved several custom oral devices to be used in the treatment of OSA. Some examples include Klearway™, Modified Herbst™, Elastic Mandibular Advancement (EMA™), Thornton Adjustable Positioner (TAP™), Adjustable PM Positioner™, Silencer™, and Oral Pressure Appliance (OPAP™). Individuals requiring these devices must have impressions of their mouths made.
POSITIONAL TREATMENT (NON-SUPINE POSTURE)
ZZOMA POSITIONAL SLEEPER
Positional treatment for sleep related disorders include devices designed to prevent individuals from rolling onto their backs (supine position) during sleep. This prevents the soft tissues of the throat from sagging down into the airway and disrupting air flow, causing snoring, breathing difficulty, and awakenings that disturb normal sleep patterns. In May 2010, the ZZOMA Positional Sleeper received premarket clearance through FDA’s 510(k) program for the treatment of mild to moderate, predominantly positional obstructive sleep apnea (OSA) and to reduce or alleviate snoring. Peer reviewed literature is limited to one small (n=38) randomized controlled crossover trial comparing the ZZOMA Positional Device to CPAP for treating OSA. Subjects were initially randomized to either a full night of CPAP therapy or positional device use then crossed over to the opposite therapy for a second full night of study intervention. Although the Zzoma device reduced AHI in the study sample, statistically significant improvement was noted for CPAP compared to baseline. Evidence at this time is insufficient to permit conclusions regarding the effect of this technology on health outcomes.
NIGHTBALANCE SLEEP POSITION TRAINER
In May 2018 the NightBalance Lunoa System received premarket clearance through FDA’s 510(k) program for the treatment of adults with positional OSA with a non-supine apnea-hypopnea index less than 20. The evidence on NightBalance Sleep Position Training device Includes RCTs and single arm studies. The RCTs suggest that the device may be as effective as oral appliances and more comfortable than positive airway pressure in patients with positional OSA. However, the studies are limited by a high dropout rate and short follow-up. A 6 month prospective study found that 64% of patients used the sleep position trainer for more than 4 h per night, but another observational study found that only a quarter of patients may be both able to tolerate the device and have a reduction in supine AHI in the short-term. Further study is needed to evaluate who may receive benefit and continue utilization after the trial period.
PALATE AND MANDIBLE EXPANSION DEVICES
Palate and mandible expansion devices function as an expander for palate/jaw/bone acting to increase pharyngeal space and propose to treat, reduce and eliminate OSA. In May 2014, the FDA gave 510(k) approval to the Mandibular Repositioning Nighttime Appliance (mRNA) an intraoral device for the treatment of mild to moderate OSA. In a 2017 study, Singh and Cress reported on a series of 19 individuals who had mild-to-moderate sleep apnea who were treated with a Daytime Nighttime Appliance (DNA) or mRNA. Only individuals who complied with oral appliance wear were included in the study. The mean AHI was reduced from 12.85 to 6.2 events per hour (p<0.001) without the appliance while the oxygen saturation index improved from 6.3 percent to 2.6 percent (p<0.001). Moreover, these devices have been studied in severe OSA. In 2016, Singh et al reported on a series of 15 consecutive individuals with severe sleep apnea who were treated with a DNA Appliance or mRNA Appliance. All individuals had failed to comply with CPAP. Pre- and post treatment AHI was assessed in a home sleep study without the oral appliance. AHI decreased from a mean 45.9 events per hour to 16.5 (p<0.01) after a mean 9.7 months of treatment. Limitations of these studies included uncertain blinding of the physician evaluating the sleep study, the small number of individuals studied, the lack of intention-to-treat analysis, and the lack of long-term follow-up.
NASAL EXPIRATORY POSITIVE AIRWAY PRESSURE (EPAP)
In December 2010, the U.S. Food and Drug Administration gave 510(k) approval to the Provent sleep apnea therapy, a nasal expiratory positive airway pressure (EPAP) device for the treatment of OSA. The Provent device, which is placed just inside the nostrils, is proposed to increase pressure in the airway in an effort to prevent the collapse of the airway during sleep. Use of the EPAP device has been reported in several prospective case series and one industry-sponsored randomized controlled trial. The main finding of the trial was a decrease in AHI with minor impact on oxygenation and the Epworth Sleepiness Scale (ESS). Evidence at this time is insufficient to permit conclusions regarding the effect of this technology on health outcomes.
ORAL PRESSURE THERAPY
Oral pressure therapy (OPT) provides light negative pressure to the oral cavity by using a flexible mouthpiece connected to a bedside console that delivers negative pressure. In October 2012, the U.S. Food and Drug Administration gave 510(k) approval to the Winx Sleep Therapy System, which uses OPT for the treatment of OSA. This device is proposed to increase the size of the retropalatal airway by pulling the soft palate forward and stabilizing the base of the tongue. Evidence at this time is insufficient to permit conclusions regarding the effect of this technology on health outcomes.
DAYTIME ELECTRICAL STIMULATION OF THE TONGUE
In February 2021, the FDA granted De Novo authorization for the eXciteOSA, a tongue muscle stimulation device intended to reduce snoring and mild OSA for individuals 18 years or older. The evidence on eXciteOSA includes 2 prospective single arm studies in individuals with primary snoring or mild OSA, no controlled trials were identified. The available evidence suggests that when used for 20 minutes a day over 6 weeks, the treatment may reduce snoring. In the overall population, the effects on AHI were not clinically significant. For the subgroup of patients with mild OSA, the improvement in AHI in these uncontrolled trials remained modest. With a mean ESS of less than 10, this group of individuals might not be considered symptomatic. Controlled studies are needed to evaluate whether patients who meet criteria for treatable OSA improve and whether individuals would continue use after the 6 week trial period.
HYPOGLOSSAL NERVE STIMULATION
In April 2014, the Inspire II Upper Airway Stimulation System (UAS) (Inspire Medical Systems) received FDA approval for use in individuals 22 years and older who have been confirmed to fail or cannot tolerate positive airway pressure treatments and who do not have a complete concentric collapse at the soft palate level. Implanted components include the implantable pulse generator (IPG), stimulation lead, and sensing lead, and external components include the physician programmer and the patient programmer (sleep remote). The IPG detects the individual's breathing pattern and maintains an open airway with mild stimulation of the hypoglossal nerve, which controls tongue movement, during inhaled breathing. The professional provider adjusts the stimulation settings using the external physician programmer. The patient sleep remote allows the individual to turn therapy on before they go to sleep and to turn therapy off when they wake up. Studies suggest that UAS may improve OSA symptoms in individuals with moderate-to-severe OSA in whom prior CPAP/BPAP did not work or was not tolerated.
The evidence on hypoglossal nerve stimulation for the treatment of obstructive sleep apnea (OSA) includes case series and a multicenter prospective, single group, cohort design study (STAR) that were surgically implanted with an upper airway stimulation device with obstructive sleep apnea who had difficulty either accepting or adhering to CPAP therapy and were followed for 5 years. Prospective cohort study is gold standard for epidemiologic studies. The study strengths included measuring primary and secondary outcomes and at 12-month visits, a second randomized study within the study where participants were randomly assigned into two groups with one group having the device turned off for 7 days and the other continued with the device turned on. Polysomnography was performed after the randomization period to measure the effects of therapy withdrawal as compared to continued use of the therapy.
Hypoglossal nerve stimulation has shown improved outcomes in this single arm study when used in a select group of patients. For the patients that met the inclusion criteria for AHI, BMI and favorable pattern for palatal collapse about two-thirds met the study definition of success. Results observed at the 12 month follow-up were maintained at 3 years. Patient based outcomes at 48 months, concluded these patients maintained a sustained benefit on patient reported outcomes (Epworth Sleepiness Score, Functional Outcomes of Sleep Questionnaire and snoring). Conclusions from the 5 year outcomes were that UAS is a nonanatomic surgical treatment with long-term benefit for individuals with moderate to severe OSA who have failed nasal continuous positive airway pressure. Safety and effectiveness were evaluated using multiple outcome measures.
For Individuals with obstructive sleep apnea who are treated with hypoglossal nerve stimulation, the evidence is sufficient to determine that the technology results in a meaningful improvement in the net health outcome.
SURGICAL TREATMENTS
Surgical treatments for OSA are used to achieve upper airway reconstruction and can be divided into phase I and phase II procedures. Phase I surgeries advance the tongue off the back of the throat by advancing the front of the jaw and consist of one, or a combination of, procedures, including uvulopalatopharyngoplasty (UPPP)/laser-assisted uvulopalatoplasty (LAUP), glossectomy, lingualplasty, genioglossus advancement with or without hyoid suspension, inferior sagittal mandibular osteotomy, and tracheostomy. Phase II surgery achieves advancement of both the maxilla and mandible and is called maxillomandibular osteotomy and advancement (MMA).
When OSA is caused by specific anatomic abnormalities of the upper airway such as, but not limited to, enlarged tonsils, enlarged adenoids, an enlarged tongue, small jaw structure, or retropalatal/retrolingual obstruction, surgery is performed to correct these anomalies. Examples of these surgical procedures are tonsillectomy, adenoidectomy, septoplasty, and genioplasty.
The following are descriptions of surgical procedures that may be performed for the treatment of OSA:
Palatopharyngoplasty (e.g., uvulopalatopharyngoplasty [UPPP], uvulopharyngoplasty, uvulopalatal flap, expansion sphincter pharyngoplasty, lateral pharyngoplasty, palatal advancement pharyngoplasty, relocation pharyngoplasty) enlarges and opens the airway by removing or shortening the uvula, removing the tonsils and adenoids if present, and/or removing part of the soft palate or roof of the mouth.
An inferior sagittal mandibular osteotomy brings the lower bone of the jaw forward, while an MMA procedure separates the maxilla and the mandible; both enlarge the retrolingual airway.
A midline glossectomy procedure reduces the size of the back of the tongue by excising a v-shaped portion of the center part of the tongue. A lingualplasty is a more aggressive procedure that additionally removes side wedges.
A genioglossus advancement procedure with or without hyoid suspension pulls the back of the tongue forward, thereby enlarging the airspace behind the tongue. It is performed under general anesthesia through an incision inside the lower lip. A rectangular or circular segment of chin bone (just below the four front teeth) is pulled forward and held in place with a titanium screw or plate. A hyoid advancement is performed by making an incision in the neck just above the Adam's apple. The hyoid bone is moved forward and attached to the Adam's apple or to the jawbone. This additional procedure also enlarges the airspace behind the tongue.
Tracheostomy is the surgical opening of the trachea to facilitate breathing. This procedure remains the surgical approach with the greatest effectiveness because it bypasses all areas of obstruction in the nasal, palatal, lingual, and pharyngeal areas. However, tracheostomy is associated with significant morbidity.
Tonsillectomy is the surgical removal of tonsils or a tonsil.
Adenoidectomy is the surgical removal of adenoids.
Septoplasty involves major repair of the nasal septum.
Genioplasty is the surgical advancement or reduction of the chin. This surgery is often performed to correct a maxillofacial abnormality that is causing OSA.
Radiofrequency ablation reduces excess tissue of the palate, uvula, and tongue base in individuals with sleep-disordered breathing associated with OSA. The Somnoplasty System (Olympus, formally Gyrus ACMI and Somnus Medical Technologies; Center Valley, PA) is a device with an FDA 510(k) approval for reducing the incidence of airway obstruction in individuals suffering from upper airway resistance syndrome or OSA. There is insufficient published peer-reviewed literature to establish the efficacy of this procedure at this time.
The ENT Coblator Surgery System (ArthroCare Corp.; Austin, TX) is a device that has FDA approval for otorhinolaryngology (ear, nose, and throat [ENT]) procedures such as throat surgery to reduce excess tissue in the uvula/soft palate for the treatment of snoring. It is also approved for traditional uvulopalatoplasty and tonsillectomy. Tissue is vaporized, one cell layer at a time, without using heat energy. There is insufficient published peer-reviewed literature to establish the efficacy of this procedure at this time.
The AlRvance™System (Medtronic, Inc.; Jacksonville, FL) and Encore™ System (Siesta Medical; Los Gatos, CA) enable minimally invasive surgical treatment of tongue- and hyoid-based obstructive sleep apnea. There are two surgical procedures that may be performed with these systems to treat OSA: the tongue suspension procedure and the hyoid suspension procedure.
The tongue suspension procedure with these systems employs a titanium screw that is secured to the anterior mandible and a permanent suture that is looped through the posterior tongue base. When the suture is tightened, the tongue base is stabilized, which prevents collapse and airway obstruction.
The hyoid suspension procedure with these systems employs two titanium screws with attached sutures that are implanted in the lower mandible. When the sutures are looped around the hyoid bone, the hyoid bone is suspended to help maintain an open airway. There is insufficient published peer-reviewed literature to establish the safety and efficacy of these systems at this time.
Palatal stiffening procedures include a cautery-assisted palatal stiffening operation (CAPSO), injection of sclerosing agents, and the insertion of palatal implants (The Pillar™ Palatal Implant System, also known as the Pillar procedure [Restore Medical Inc.; St Paul, MN acquired by Medtronic, Inc.; Jacksonville, FL in 2008]).
The CAPSO procedure uses a cautery to induce a midline palatal scar designed to stiffen the soft palate to eliminate excessive snoring. There is insufficient published peer-reviewed literature to establish the safety and efficacy of this procedure at this time.
The Pillar procedure involves the placement of three tiny woven inserts that stiffen the structure of the soft palate to help reduce the vibration that causes snoring and limit the ability of the soft palate to obstruct the airway. The Pillar™ Palatal Implant System has FDA 510(k) approval. The device is a cylindrical-shaped segment of braided polyester filaments that is permanently implanted submucosally in the soft palate. It is intended to reduce the incidence of airway obstruction in individuals suffering from mild-to-moderate OSA.
There is insufficient published peer-reviewed literature to establish the efficacy of palatal stiffening procedures at this time.
Laser-assisted uvulopalatoplasty (LAUP) utilizes a carbon dioxide (CO2) laser that progressively reshapes the uvula and associated soft-palate tissues in order to enlarge the oropharyngeal airway. Less tissue is removed than with UPPP, as LAUP usually does not remove tonsils or lateral pharyngeal wall tissues. The procedure, using local anesthesia, is typically performed in an outpatient setting three to seven times and at three-to-four week intervals. LAUP cannot be considered an equivalent procedure to the standard UPPP, with the laser representing a surgical tool that the provider opts to use. There is insufficient published peer-reviewed literature to establish the efficacy of LAUP at this time.