Soft-palate implants for obstructive sleep apnoea (interventional procedures consultation)

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional Procedure Consultation Document

Soft-palate implants for obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is a breathing disorder in which the airway is blocked intermittently and repeatedly during sleep, as the muscles of the mouth and throat relax. Patients with OSA usually snore and experience sleep disturbance and daytime sleepiness. The soft palate (part of the roof of the mouth) is involved in OSA in some patients. Small pieces of synthetic fibre can be implanted into the soft palate, with the aim of making it stiffer and less likely to collapse during sleep.


The National Institute for Health and Clinical Excellence is examining soft-palate implants for obstructive sleep apnoea and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about soft-palate implants for obstructive sleep apnoea.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

  • comments on the preliminary recommendations
  • the identification of factual inaccuracies
  • additional relevant evidence.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows.

  • The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
  • The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the Institute's website (www.nice.org.uk/ipprogrammemanual).

Closing date for comments: 21 August 2007
Target date for publication of guidance: December 2007


Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.


1 Provisional recommendations
 
1.1 Current evidence on soft-palate implants for obstructive sleep apnoea (OSA) raises no major safety concerns, but there is inadequate evidence that the procedure is efficacious in the treatment of OSA. Therefore, soft-palate implants should not be used in the treatment of this condition.
 
 
2 The procedure
 
2.1 Indications
 
2.1.1 OSA is characterised by repeated, reversible episodes of apnoea (temporary suspension of breathing) and hypopnoea (abnormally slow or shallow respiration) during sleep, loud snoring and excessive daytime sleepiness.
2.1.2 The soft pharyngeal structures of patients with OSA collapse when the patient is asleep, causing apnoea or hypopnoea (reduction of airflow by at least 50% over 10 seconds or more). In response to an apnoea/hypopnoea episode the patient will spontaneously move or waken, often subconsciously, to reopen the airway. The apnoea/hypopnoea episodes can recur through the night. This disturbs both the patient and their sleeping partner. OSA is associated with extreme daytime sleepiness, although patients themselves may be unaware of the condition. OSA is more common in obese individuals and can be exacerbated by alcohol consumption and sedative medication.
2.1.3 The diagnosis and severity of OSA can be confirmed by sleep studies, which involve inspiratory airflow measurement, pulse oximetry, recording of snoring, EEG recording of sleep patterns or video recording. The apnoea-hypopnoea index (AHI) is the combined number of apnoea and hypopnoea episodes experienced on average per hour of sleep. An AHI score of 5-14 events per hour is defined as mild, 15-30 as moderate, and a score above 30 as severe OSA
2.1.4 OSA may be improved by various lifestyle changes such as weight loss, smoking cessation, changes in sleeping position and avoidance of alcohol or sleeping tablets. Continuous positive airway pressure (CPAP) is most commonly used for severe OSA. Mandibular advancement devices, injection snoreplasty (injection of sclerosant into the soft palate), radiofrequency ablation of the soft palate, laser-assisted uvulopalatoplasty, uvulopalatopharyngoplasty and cautery-assisted palatal stiffening have also be used.
 
 
2.2 Outline of the procedure
 
2.2.1 Under local anaesthesia, a hollow introducer needle containing the implant is used to pierce the soft palate close to the junction with the hard palate, into its muscle layer. The needle is then withdrawn, leaving the implant in position. Mirror examination or nasal endoscopy may be used to check that the implant has not penetrated the nasal surface of the soft palate. Typically, two or three implants are inserted in a single procedure, at the midline of the soft palate or parallel to it. The implants may be removed with forceps if necessary. The aim of the procedure is to stiffen the soft palate over subsequent weeks as a result of fibrosis.
 
 
2.3 Efficacy
 
2.3.1 In four case series of patients treated with soft-palate implants and with follow-up of between 3 and 6 months, mean AHI decreased from 25.0 to 22.0 (n = 63, p against baseline = 0.05), from 12.7 to 11.5 (n = 29 patients, not significant), from 16.2 to 12.1 (n = 25, p = 0.033), and from 33 to 25 (n = 23 p < 0.05).
 
2.3.2 Three case series of 63, 25 and 23 patients reported baseline daytime tiredness (measured using the Epworth sleepiness scale [ESS] from 0 [best] to 24 [worst]). At follow-up intervals between 3 and 6 months, there were significant reductions from baseline in mean ESS scores from 11.0 to 6.9, 9.7 to 5.5, and 13.2 to 8.7, respectively (p < 0.001 for all). A case series of 29 patients reported a reduction in ESS score in 52% (15/29) of patients (4-6 months' follow-up).
2.3.3 In the two case series of 63 and 23 patients, the mean lowest oxygen saturation during sleep was reported as 81.8% and 87% at baseline, and 83.2% and 89% at 90 days' and 6 month follow-up respectively (n = 53, not significant at 90 days and p < 0.05 at six months). For more details, refer to the sources of evidence (see appendix).
2.3.4 The Specialist Advisers considered key efficacy outcomes to be reduction in snoring, change in AHI, sleep quality, oximetry, snoring intensity and quality of life.
 
2.4 Safety
 
2.4.1 In four case series, extrusion of the implant was reported in 8% (2/25) of patients (74-100 days' follow-up), none of 23 patients (6 months' follow-up), 2.7% (10/372) of implants (n = 125 patients, 4-6 months' follow-up), and 10% (20/202) of implants (n = 63 patients, 90 days' follow-up). Most studies reported that extruded implants were easily removed, however the study of 29 patients reported that ?considerable force' under local anaesthesia was required to remove one extruded implant.
2.4.2 The two case series that combined patients with mild OSA and simple snoring reported partial extrusion of implants in 18% (6/34) and 17% (2/12) of patients or 9% (9/102) and 9% (3/34) of implants, respectively.
2.4.3 Mucosal irritation or ulceration at the site of implantation occurred in 6% (4/63) of patients in one case series and resolved within 2 weeks. Case series of 23, 34 and 12 patients reported that no patients experienced infection or inflammation at the implantation site. No other adverse effects were reported in any of the studies. For more details, refer to the sources of evidence (see appendix).
2.4.4 The Specialist Advisers considered potential adverse events to include sepsis, local infection, migration or extrusion of the implant, failure of the implant, ?foreign-body' sensation, minor scarring of the soft palate and compromise of CPAP.
   
   
 
2.5 Other Comments
2.5.1 The Committee noted specialist advice that the soft-palate implants might exceptionally be appropriate for the treatment of snoring associated with sleep apnoea.
3 Further Information
3.1 The Institute has issued Interventional Procedures (IP) guidance on radiofrequency ablation of the soft palate for snoring (ipg124) and is developing IP guidance on soft-palate implants for simple snoring (/). NICE is also developing Technology Appraisals guidance on continuous positive airway pressure (CPAP) for the treatment of sleep apnoea (/proxy/?sourceUrl=http%3a%2f%2fguidance.nice.org.uk%2fpage.aspx%3fo%3d350198).
 
 
   

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
July 2007

Appendix: Sources of evidence
 

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

  • 'Interventional procedure overview of soft-palate implants for obstructive sleep apnoea, March 2007'

Available from: www.nice.org.uk/ip404overview.

This page was last updated: 30 March 2010