Adult Obstructive Sleep Apnoea

Adult Obstructive Sleep Apnoea


What is Obstructive Sleep Apnoea?

Obstructive Sleep Apnoea (OSA) is a condition where the upper airway (nose, pharynx, soft palate, tongue) collapses during sleep when muscle tone is reduced. This results in repetitive periods when one is trying to breathe, but cannot move any air due to blockage (obstruction) in the upper airway. The result is:

  • The brain wakes up to a lighter level of sleep in response, so sleep is interrupted and fragmented. These sleep interruptions can occur hundreds of times during a sleep period. Although the sufferer may be unaware of these “micro-arousals” from sleep, it often manifests as fatigue and somnolence during the day.
  • The pauses in breathing are usually accompanied by a reduction in oxygen levels in the blood, causing damage in tissues, especially blood vessels. This leads to longer term effects including an increased risk of high blood pressure, heart attack, stroke and cardiac rhythm disturbance (arrhythmia).

anatomy of the pharynx and airway collapse during sleep apnoeaWhat are the Risk Factors for Obstructive Sleep Apnoea?

Sleep apnoea occurs because of a combination of:

  • Predisposing anatomy in the upper airway – the airway may already be “crowded” or narrow.
  • Loss of muscle tone during sleep, particularly deep (REM) sleep.

The degree to which anatomy and muscle tone contribute varies amongst individuals.

Risk factors for sleep apnoea include:

  • Age – as you get older, our muscle tone in the tissues of the throat is reduced, and ligaments in the throat become more lax.
  • Overweight/Obesity – collections of fat around the pharynx and tongue may compress and narrow the upper airway. Nevertheless, it is incorrect to assume that only overweight people get sleep apnoea. It really depends on ones underlying craniofacial skeleton and muscle tone. Some people are deficient (on population averages) in their craniofacial skeleton and hence have sleep apnoea even with a normal body mass index.
  • Being male (however, it is probably under-diagnosed in women).
  • Genetic predisposition.
  • Smoking – causes inflammation in the upper respiratory tract, with swelling of mucous membranes.
  • Alcohol use – alcohol is a sedative and impairs muscle tone further.

Symptoms of Sleep Apnoea

Symptoms of sleep disordered breathing include:

  • Choking or gasping episodes during sleep
  • Loud, repetitive snoring
  • Recurrent awakenings overnight
  • Unrefreshing sleep
  • Excessive daytime sleepiness
  • Impaired concentration / difficulty staying alert
  • Morning headaches
  • Personality changes
  • Decreased memory
  • Impotence
  • Depression

Why is it Important to Treat?

Early recognition and treatment of sleep apnoea is important. It may be associated with excessive sleepiness, which in turn may cause significantly reduced quality of life, and increased risk for workplace accidents or car accidents.

Moderate and severe obstructive sleep apnoea are associated with an increased risk of other medical conditions, including irregular heartbeat, high blood pressure, heart attack, and stroke.

How is it Diagnosed?

Symptoms alone correlate poorly with presence or absence of sleep apnoea. In anyone who snores and has other symptoms above, or anyone who snores and has high blood pressure, there would be a high index of suspicion. However, individuals who snore and have no other symptoms may still have sleep apnoea. The only objective measure is a sleep study or polysomnogram. I would advocate anyone undergoing surgery for snoring has a sleep study prior to intervention (except in uncommon circumstances such as massive enlargement of tonsils but otherwise favourable anatomy).

A sleep study involves monitoring and recording a number of parameters:

  • Breathing and air flow through the mouth and nose
  • Oxygen levels
  • Brain activity (stage of sleep)
  • Cardiac activity
  • Body movements

The data is analysed according to complex criteria, to indicate a diagnosis and recommendations for treatment.

Treatment Options for Obstructive Sleep Apnoea

Continuous Positive Airway Pressure (CPAP): Uses a pump to generate a positive pressure in a tube which is delivered to the upper airway via a mask that fits over the patient’s nose or nose and mouth. This is the gold standard for treating sleep apnoea. It can overcome airway collapsibility, but the problem is tolerance of the device. Some patients find it too claustrophobic or have difficulties with air leaks. Portability is another issue. Sometimes, people struggle with CPAP because of nasal blockage, and in this setting, compliance can be increased by surgery to improve the nasal airway.

Mandibular Advancement Splint (MAS): This is a mouth guard designed so that this lower guard advances forwards on the upper guard. This pulls the lower jaw forwards whilst using the appliance, which pulls the tongue forwards and indirectly stabilises the pharynx by pulling on ligaments attached to the tongue base. It can be very effective for snoring and mild sleep apnoea, but efficacy falls with increasing severity of the disorder. The splint needs to be made up by a dentist. Off the shelf solutions will invariably be uncomfortable to wear and poorly tolerated.

Surgery: Over the last 15 years, significant advances have been made in surgical options for management of obstructive sleep apnoea. Newer, more complex operations have been developed, driven by a better understanding of upper airway physiology. Detailed treatment protocols have subsequently evolved, culminating in better treatment efficacy and outcomes.

Surgery for Obstructive Sleep Apnoea (Airway Reconstruction Surgery)

No two patients are exactly the same in terms of anatomy and airway collapsibility when asleep, so treatment begins with a thorough clinical assessment to identify levels of collapse in the airway, which are often multiple. In patients with sleep apnoea, the upper airway behaves like a long tube, with a number of floppy “choke points”. One of these is often most significant, with secondary choke points around it. All areas have to be stabilised to achieve treatment success. With each stage of surgery a number of these choke points may be addressed (with a number of procedures combined together in one sitting), but there is a limit to what can be done at any one time, so more than one stage may be necessary to achieve full control. Sometimes multiple procedures are required to control a single choke point. Prior to commencing the surgical protocol, specialised scans of the upper airway are obtained to determine underlying bone and soft tissue anatomy, and help plan what procedures are most likely to give benefit.

One way to evaluate the choke points in the airway is a technique known as sleep (sedation) endoscopy. This procedure involves administration of sedative medication by an anaesthetist to simulate the loss of muscle tone normally seen during deep sleep, and induce snoring. A fibre-optic endoscope is then passed via the nose to evaluate levels of airway collapse. Whilst the technique simulates sleep, because it is induced by medication it is not a perfect representation of sleep physiology. Clinical assessment has now evolved to the point where a decision regarding appropriate surgery can be made confidently, so sleep endoscopy is no longer required in most cases, and is less frequently performed. It can still be helpful in planning further stages of surgery, where the impact of the initial stage(s) is not clear.

Initial surgery may focus on improving the nasal airway. Addressing anatomical problems in the nose will not reduce or cure sleep apnoea, but it is important to set the scene for any further surgery that may be required. If there is turbulent air flow through the nose, the rest of the airway “downstream” becomes more collapsible. Mouth breathing also compromises the airway further by rotation of the lower jaw (mandible) which pushes the tongue base backwards. Nasal surgery may also be helpful in improving compliance with other modalities such as CPAP or a MAS.

Airway reconstruction surgery is designed to either remove or re-orientate soft tissues to increase the airway diameter and stability, or to shift tissues by working on the underlying skeleton (upper and lower jaws). The latter procedures are designed not to alter dental occlusion. Some of the procedures performed include:

On the palate:

  • Radiofrequeny ablation
  • Tonsillectomy
  • Various modifications of uvulopalatopharyngoplasty
  • Transpalatal advancement pharyngoplasty

On the tongue:

  • Lingual tonsillectomy
  • Geniotubercle advancement
  • Submucosal lingualplasty (tongue volume reduction)
  • Trans-cervical tongue volume reduction
  • Hyoid suspension / advancement
  • Radiofrequency tongue base ablation

Outcomes of Airway Reconstruction Surgery

Treatment goals are two-fold. The first is to reduce long term cardiovascular risk, by reducing the severity of the sleep apnoea. Whilst CPAP can usually completely abolish any obstructive episodes, use of a CPAP machine for 4 hours a night, 5 days a week is considered adequate treatment. This is less than half of usual sleep time. Surgery may not completely abolish apnoeas, but any improvement from airway surgery will be in effect for the entire sleep time. There is evidence that a full response part of the time (ie. CPAP) is equivalent to a partial response all of the time (ie. surgery) in terms of risk reduction. As such, based on sleep study data, we may accept a less than “perfect” result, provided this is not associated with long term health risk.

The second goal is to control short term symptoms, including snoring and daytime tiredness.

Overall, about 50% of patients will have a successful outcome from one stage of surgery, rising to 70-80% with a second stage. Occasionally further stages are required to achieve control, with success rates increasing with each additional stage.

Recovery from each stage of surgery can be a little variable, but in general one would expect 1 to 2 nights in hospital, two weeks for initial discomfort to settle, and about 4 weeks for swallowing and speech to return close to pre-surgical functioning. Risks of surgery depend on the procedures being performed.

A repeat sleep study is generally obtained after 3 months following a stage of surgery, to see if a further stage is required. It is important to have objective evidence of success, as improvement in snoring and daytime tiredness does not necessarily correlate with improvement in sleep apnoea (though is usually a good indicator of improvement).

10% of patients who continue through airway reconstruction protocols will still have sleep apnoea despite treatment. For these patients, there is the option of maxillo-mandibular osteotomy and advancement (moving both upper and lower jaws forwards). This can increase rates of success to in excess of 95%. Occasionally, if patients are significantly deficient in upper and lower jaws, they will benefit most from MMOA as an initial procedure, though this needs to be carefully considered, as it is a potentially more morbid procedure that impacts on facial appearance.

An important factor that will influence outcome is weight, with chance of success significantly reduced once body mass index (BMI) is above 36. Patients in this category would be better served by weight reduction, and may be candidates for weight reduction surgery (bariatric surgery) provided they have made appropriate dietary and lifestyle changes.

With regard to long term outcomes, data suggests that if control of sleep apnoea is achieved now, that stability in the airway will remain in 10 years, unless there is significant weight gain.


Dr Schembri undertook post graduate training in airway reconstruction surgery for obstructive sleep apnoea, under the mentorship of the late Dr Samuel Robinson (one of the pioneers of modern day sleep apnoea surgery). He has several years of experience with airway surgery for management of snoring and sleep apnoea, and has developed and refined surgical protocols over this time with a positive impact on outcomes.