Drug-induced sleep endoscopy (DISE): what it is and why it matters
For patients with obstructive sleep apnoea or significant snoring who are considering surgical treatment, drug-induced sleep endoscopy (DISE) represents one of the most important advances in the field in recent decades. It allows clinicians to observe precisely what happens to a patient's airway during sleep, providing information that no other investigation can reliably replicate. DISE is not simply an additional test. It is the investigation that allows sleep apnoea surgery to be planned with precision.
DISE does not simply inform surgical planning. In many cases, it fundamentally changes it.
Why is observing the airway during sleep so important?
Obstructive sleep apnoea and snoring result from collapse or narrowing of the upper airway at one or more sites during sleep. The nose, soft palate, tongue base and throat can all contribute to obstruction, and the pattern varies considerably between individuals. A clinical examination carried out while the patient is awake gives only a limited picture of what is happening during sleep: the relevant muscles are toned, the airway is supported, and the conditions that lead to collapse are simply not present. For patients who have not yet had a home sleep study, this is typically the investigation that precedes DISE in the diagnostic pathway.
Without DISE, surgical decisions for sleep apnoea are based partly on inference. With it, the surgeon can see exactly where the airway is failing, and plan accordingly.
DISE changes this fundamentally by creating controlled, reproducible sleep-like conditions and allowing the surgeon to examine the airway in real time.
What does the procedure involve?
DISE is performed as a day-case procedure in a clinical setting. A short-acting sedative (typically propofol) is administered by an anaesthetist to induce a state of light sedation that closely mimics natural sleep. The drug is carefully titrated to reproduce the muscle relaxation associated with sleep without causing deep anaesthesia.
Once the patient is sedated, the surgeon passes a thin flexible endoscope through the nose and into the throat. This allows direct visualisation of the nasopharynx, soft palate, lateral pharyngeal walls, tongue base and epiglottis. The surgeon observes how and where the airway collapses, records the pattern of obstruction, and assesses the degree of movement in each region.
The entire procedure typically takes around fifteen to twenty minutes. Patients wake quickly once the sedative is stopped and are usually ready to go home within one to two hours.
What can DISE reveal?
DISE identifies the specific sites and patterns of airway collapse, which can include:
Palatal collapse: the soft palate falls backwards to obstruct the airway, either partially or completely.
Lateral wall collapse: the sidewalls of the throat narrow inwards.
Tongue base obstruction: the base of the tongue falls posteriorly to block the airway.
Epiglottic collapse: the epiglottis folds downwards, an important finding with direct implications for surgical planning.
Multi-level obstruction: collapse occurring at more than one site simultaneously, which is common.
How does DISE change treatment decisions?
The impact of DISE on surgical planning is significant. Studies have consistently shown that DISE findings lead to changes in the planned surgical approach in a substantial proportion of patients: in some series, the approach was altered in more than half of cases compared with decisions based on awake examination alone.
Where palatal collapse is the primary finding, palatal surgery is likely to be most effective. Where tongue base obstruction is prominent, different techniques are required. Where epiglottic collapse is identified, this changes both the technical approach and the expected outcome. In patients with multi-level obstruction, a staged or combined surgical plan can be designed with confidence.
Equally importantly, DISE can identify patients in whom surgery is unlikely to be effective, sparing them an operation that would not address the true cause of their obstruction, and directing them towards alternative treatments such as CPAP or mandibular advancement therapy. A full overview of available treatment options is outlined on our snoring and sleep wellness page.
What patients often misunderstand about surgical treatment for sleep apnoea
One of the most consequential misconceptions among patients considering surgery is that any nasal procedure will adequately address their apnoea. In reality, nasal surgery that improves airflow but does not address palatal or tongue base collapse may reduce snoring noise without meaningfully improving apnoea severity, a clinically important distinction that DISE is specifically designed to clarify before surgery is undertaken.
Is DISE uncomfortable or risky?
DISE is a safe and well-tolerated procedure. Patients are sedated throughout and have no awareness of the endoscopy. The sedative wears off rapidly and the vast majority of patients describe the experience as straightforward. A period of observation after the procedure is standard, and patients should arrange to be accompanied home.
Who is DISE recommended for?
At Hillser Clinic, DISE is recommended for patients with significant snoring or confirmed obstructive sleep apnoea who are considering surgical treatment, or in whom the pattern of obstruction is uncertain following initial assessment. It is also used in cases where a previous surgical procedure has not delivered the expected result, and a more detailed understanding of residual obstruction is needed before further intervention is considered.
Not every patient who presents with sleep apnoea or snoring will require DISE. For patients being managed with CPAP or a mandibular advancement device who are doing well, the investigation adds little. Its value lies specifically in the surgical planning context, where the precision it provides directly improves both the selection of the right procedure and the likelihood of a successful outcome.
Our doctors will advise during your consultation whether DISE is appropriate for your specific circumstances and what the findings are likely to add to your management plan.
Frequently asked questions about DISE
Is DISE painful?
No. Patients are sedated throughout the procedure and have no awareness of the endoscopy being performed. The sedative used is short-acting and wears off quickly, and the vast majority of patients describe the experience as entirely comfortable. A short period of observation following the procedure is standard before discharge.
How long does DISE take?
The procedure itself typically takes fifteen to twenty minutes. Including preparation and the post-procedure recovery period, most patients are ready to go home within one to two hours of arrival. You will need to arrange to be accompanied home, as you will have received sedation.
Will DISE definitely mean I need surgery?
Not necessarily. DISE is a diagnostic investigation, not a commitment to surgery. In some cases the findings confirm that surgery is well-indicated and identify the most appropriate procedure; in others, they suggest that surgery is unlikely to be effective and that non-surgical management is the better path. The purpose of DISE is to ensure that any subsequent treatment decision is based on precise clinical evidence rather than inference.
How soon after DISE will I know the results?
Your surgeon will review the endoscopic recording with you at a follow-up appointment, typically within a short period after the procedure. The findings will be explained clearly, including which sites of obstruction were identified and what they mean for your treatment options. You will have the opportunity to ask questions and to take as much time as you need before making any decisions.
Can DISE be done under local anaesthetic?
No. DISE requires light sedation administered by an anaesthetist in order to reproduce the muscle relaxation that occurs during natural sleep. This is what makes the investigation clinically meaningful: a flexible endoscopy performed on a conscious, awake patient cannot replicate the conditions that cause airway collapse during sleep and would not provide the same diagnostic information.
Is DISE available privately at Hillser Clinic?
Yes. DISE is available as a private day-case procedure at Hillser Clinic, with rapid access and a clear pathway from assessment through to results review. The procedure includes a pre-procedure consultation, the endoscopy itself, and a follow-up appointment to discuss findings and treatment options.
Book a DISE assessment at Hillser Clinic
If you have been diagnosed with obstructive sleep apnoea or significant snoring and are considering whether surgery might be appropriate for you, DISE provides the most accurate basis for that decision currently available. Ms Maria Pulido offers drug-induced sleep endoscopy at Hillser Clinic as part of a comprehensive sleep surgery assessment pathway. To arrange a consultation or to find out whether DISE is the right next step for you, please contact our team.
