SLEEP APNOEA SURGERY FAQ:

Is sleep apnoea only a disorder of obese people?

The majority of the population have what we call an “intermediate craniofacial load”. What this really means is that at normal weight we have sufficient anatomical space that we do not have sleep apnoea. As we gain weight we deposit fat around the throat (pharynx) and this leads to compromise of the airway. A few people have such fantastic craniofacial skeletons that they can gain a large amount of weight and still have no airway compromise. 30% of the population have a “deficiency” of their craniofacial skeleton, so may have sleep apnoea even at normal body weight, simply because there is not enough room. So the disorder is not just one of obese people, and it can affect young adults as well.

Why is it important to have surgery as an option for sleep apnoea?

Sleep apnoea is a disorder that can have potentially serious and detrimental long term health implications. That moderate and severe sleep apnoea warrants treatment is fairly universally accepted. CPAP (a machine that delivers positive air pressure to splint the airway open) is an effective treatment, when it’s tolerated! For CPAP to be considered effective, you need to use it 4 hours per night for 5 nights a week. That’s about half of average sleep time in adults. Yet with this in mind, compliance rates with CPAP are only 40%. Many people cannot tolerate having a mask strapped to their face whilst asleep. Additionally, although modern machines are very good, the device can still cause partner disturbance. For many young people, the thought of spending the rest of their life with a CPAP machine is daunting, not to mention the impracticalities of travel.

A second conservative option is a mandibular advancement splint (a jaw splint designed to pull the lower jaw forwards, and hence pull the tongue forwards). Efficacy of such splints is inversely proportional to the severity of sleep apnoea. If these two options fail or are not tolerated, there is an option of surgery to try and increase airway space and stabilise the upper airway during sleep.

Is surgery a perfect treatment? Definitely not. Is everyone cured? No (see below). Is it for everyone? No. Does it carry some risk? Yes. Nevertheless, where other conservative options have failed, it is a reasonable option for management.

Although I am a surgeon, I always advocate conservative treatment first, if my patient is entertaining the idea. Nevertheless it is reasonable to consider surgery as the first option for treatment in some cases, for reasons cited above.

I heard / read that sleep apnoea surgery has a bad reputation, is this true?

For many years, the scope of surgery for snoring and sleep apnoea was confined to one operation, uvulopalatopharyngoplasty. Understanding of upper airway physiology was in its infancy, and not surprisingly this one operation failed to address the full problem in many cases. It is also a procedure that carries some morbidity in terms of recovery, because of associated pain. It is no wonder that the concept of surgery for sleep apnoea became an idea that was baulked at by our respiratory medicine colleagues.

Furthermore, even with modern airway surgery techniques, proving surgery works is a challenge. We know it can help people on a case by case basis, but the highest level of evidence demands a double blind, randomized, prospective, controlled trial. This may be possible for a trial of a new drug, but it is impossible to blind a surgeon to the operation he or she is performing, and unethical to subject patients to a “sham” operation for comparison purposes! This is true of any surgery – we know taking out a gallbladder for gallstones improves quality of life, but there is no highest level evidence to support this. Fortunately, sleep surgeons have always placed stringent criteria on defining surgical success, and because of previous criticism over surgery, more and more well designed trials demonstrating surgical efficacy are being published each year.

The concept of multi-stage protocols for management of sleep apnoea dates back to 1993, when Riley & Powell (Stanford) published their data on surgical management of sleep apnoea. Several procedures for managing the upper airway have been conceived and have evolved since. Each year, outcomes from current protocols are assessed and the protocols are refined to try and maximise outcomes in the smallest number of stages possible, depending on the patient’s clinical and radiological assessment of their anatomy. As a result, modern airway surgery protocols are robust and outcomes are good.

Will I be cured with a straightforward or single operation?

Unfortunately in most cases, this is not correct. There is a small group of patients who have very “favourable” facial skeletons and soft tissue anatomy that makes surgeons “jump for joy”, as we know we can help the problem with a relatively straightforward surgical procedure. For example, massive enlargement of the tonsils. You can predict success with a tonsillectomy or uvulopalatopharyngoplasty procedure alone. The majority of people, however, will have some craniofacial predisposition to sleep apnoea, as well as anatomical soft tissue problems, and poor muscle tone when asleep. In order to combat all of these, a number of procedures may be necessary. We can usually perform more than one procedure in one sitting (known as a stage of surgery), though there is a limit to what people will tolerate and what is safe or technically feasible. Many people, then, will require more than one stage of surgery. This is what modern airway surgery is all about, a calculated step-wise approach to deal with the anatomical problems in the airway. I certainly do not pretend that it is an easy path to take, but having said this not many people drop out of the surgical protocols once they have started on this path (although they are of course free to do so at any stage). You can read about outcomes below.

What is a radiofrequency (ablation / coblation) procedure on the tongue?

Radiofrequency tongue base channelling involves using a fine needle point probe that is inserted into the tongue muscle at several different anatomical points, using bursts of radiofrequency energy to dissolve tissue and produce some reduction in volume and some scar tissue which helps tension the tongue and stop it from falling back and obstructing the airway. It is a procedure with a relatively low risk profile and relatively easy recovery. There has been some press in the not too distant past suggesting that minimally invasive tongue surgery can cure up to 70% of patients. What was not mentioned were the other procedures that were done at the same time. Nor was there mention of patient selection and severity of the disorder prior to surgery.

When looking objectively at the technique, there certainly is an attraction with how easily it can be performed (and taught to other surgeons), and the low risk profile to the patient. However, volumetric analysis of tongue tissue pre and post treatment, suggests that the technique has a modest effect at best. Of course if this was the magic bullet, it would be performed much more widely. This does not mean it does not work or should not be done. It is a useful adjunctive procedure in many cases, but does not carry the same power in terms of volume reduction as submucosal lingualplasty or trans-cervical tongue volume reduction. So patients with moderate to severe sleep apnoea with unfavourable anatomical proportions that lead to collapse of the airway at the level of the tongue, are less likely to benefit, and we may advocate more invasive surgery as the first stage, based on current protocols.

I have a high body mass index (BMI) – how effective is sleep surgery?

As we gain weight, we deposit fat around the tongue base and pharynx, leading to further compromise of the pharyngeal airway. Where BMI is greater than 36, airway surgery for sleep apnoea is unlikely to be effective.

At this level, there are several reasons to consider weight reduction, because of potential effects such as osteoarthritis, hypertension, hypercholesterolaemia, gastro-oesophageal reflux, and impaired glucose tolerance / diabetes mellitus. Lifestyle modification alone (diet and exercise) may be insufficient, because once you reach this weight, body metabolism changes considerably to favour fat retention. In addition, finding the energy to exercise on the background of sleep apnoea can be problematic.

Such patients may benefit from bariatric surgery (weight reduction surgery, such as gastric bypass or gastric sleeving), provided the lifestyle modification is in place prior to surgery, as keeping the weight off is the key.

What are the success rates with surgery?

With surgery we aim to do two things. The first is reduce long term risk of cardiovascular disease. The second is eliminate acute symptoms such as snoring and daytime tiredness. We may accept a less than perfect result on a sleep study following surgery, if the above criteria are met. There is evidence that improvement with surgery (even if not absolute cure on the basis of the figures on the sleep study) is as good as the average use of CPAP in terms of health benefit. You can read more about sleep apnoea surgery here.

ABOUT THE AUTHOR, DR MARK SCHEMBRI:

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.

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