Drug-induced sleep endoscopy (DISE)
Drug-induced sleep endoscopy (DISE) is a specialised diagnostic procedure used to evaluate the upper airway in patients with suspected obstructive sleep apnoea (OSA) or other sleep-related breathing disorders. It allows direct visualisation of the airway while the patient is in a sleep-like state, helping to identify the exact site and pattern of obstruction.
Mr Ryan Chin Taw Cheong, leading ENT and sleep surgeon at Cleveland Clinic London Hospital, goes into expert detail as to why this targeted approach supports more precise treatment planning, and can improve outcomes for patients who don’t respond to standard therapies.
What is drug-induced sleep endoscopy?
DISE involves the use of a flexible endoscope to examine the airway while the patient is under light sedation. The sedation mimics natural sleep, allowing the specialist to observe how the airway behaves during breathing.
Unlike standard examinations performed while the patient is awake, DISE provides dynamic, real-time information about airway collapse, including which structures are involved and how severe the obstruction is.
Why is DISE performed?
DISE is typically recommended for patients with suspected or confirmed obstructive sleep apnoea, particularly when symptoms persist despite initial treatment.
It’s often used to:
- Identify the level of airway obstruction, such as the nose, soft palate, tongue base or larynx
- Assess the pattern of airway collapse during sleep
- Guide selection of the most appropriate treatment
- Evaluate patients who are unable to tolerate continuous positive airway pressure (CPAP) therapy
By identifying the specific cause of airway obstruction, DISE helps tailor treatment to the individual patient.
What happens during the procedure?
DISE is usually carried out as a short day-case procedure. A sedative medication is administered to induce a controlled sleep-like state while maintaining spontaneous breathing.
Once the patient is adequately sedated, a thin, flexible endoscope is gently passed through the nose to examine the airway. The specialist observes the movement and collapse of airway structures during breathing.
The procedure typically takes around 15 to 30 minutes. Throughout the examination, oxygen levels, heart rate and breathing are carefully monitored to ensure safety.
What types of airway obstruction can be identified?
DISE can identify different patterns and levels of airway collapse, which may vary between individuals.
Common findings include:
- Collapse at the level of the soft palate, often contributing to snoring
- Tongue base obstruction, where the tongue falls backward during sleep
- Lateral wall collapse, involving the sides of the throat
- Epiglottic collapse, where the epiglottis partially blocks the airway
In many cases, more than one site of obstruction is present, which is why a detailed assessment is important.
How does DISE influence treatment decisions?
The information obtained during DISE helps guide treatment planning. Rather than using a one-size-fits-all approach, management can be tailored to the specific pattern of airway obstruction.
Treatment options may include positional therapy, oral appliances, or targeted surgical procedures aimed at the identified areas of collapse. In some cases, DISE can help determine whether a patient is suitable for advanced treatments such as hypoglossal nerve stimulation.
This personalised approach improves the likelihood of successful symptom control.
Is DISE safe?
DISE is considered a safe and well-tolerated procedure when performed by an experienced team. The sedation used is carefully controlled, and patients are closely monitored throughout.
After the procedure, patients may feel slightly drowsy for a short period but can usually return home the same day. Temporary nasal discomfort or mild throat irritation may occur but typically resolves quickly.
What are the benefits of DISE?
DISE provides valuable insights that cannot be obtained through standard awake examinations. By identifying the precise cause of airway obstruction, it allows for more accurate diagnosis and targeted treatment.
For patients with complex or persistent symptoms, this can lead to more effective management, improved sleep quality and better overall health outcomes.