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Trans-nasal oesophagoscopy (TNO)

Patient information A-Z

What is a trans-nasal oesophagoscopy?

A trans-nasal oesophagoscopy is a procedure which allows the doctor to examine your nose, throat and upper gullet under local anaesthetic using a small flexible telescope passed through the nose.

Information about your procedure

Patients who require investigations into their throat and upper gullet have usually needed to be put to sleep for this procedure (general anaesthetic). Trans-nasal oesophagoscopy is a new technique available at the Addenbrooke’s hospital, Cambridge, which enables the doctor to examine patients under local anaesthesia in the outpatient clinic using a small flexible telescope passed through the nose. This avoids the need for admission to hospital and reduces the risk to patients by avoiding a general anaesthetic.

Before your appointment

  • Do not eat or drink for four hours before the test. Normal medicines should be taken but use as little water as possible.
  • Make sure you inform the medical or nursing staff about any allergies that you have.


  • If you take blood thinning tablets such as Warfarin or Clopidogrel or other thinners, make sure you let the team know in advance as they may want you to stop this medication for 2 to 5 days before the procedure.

Patients with diabetes

If you use insulin to control your diabetes you should consult with your GP as you will need to adjust your morning insulin as you will not be able to eat or drink on the morning of your test.

What happens at my appointment?

The test is carried out in the outpatient department; you will be awake the entire time. The doctor will explain the procedure to you and ask you to sign a form to consent to the examination and in some cases to for the recording and use of images from the investigation.

  • A local anaesthetic spray will be sprayed into your nose and throat. This takes a few minutes to work properly.
  • A flexible telescope will then be placed in your nose and passed into your throat and down into the swallowing tube (oesophagus).
  • The doctor also passes some air or water into the swallowing tube through the telescope, this can make you belch which is normal.
  • You are able to breath, swallow and cough quite normally during the investigation.

Some patients may require a biopsy (where the doctor takes a small sample of tissue) or other procedures. These can often be performed at the same time as the examination although a further admission for a procedure under general anaesthesia may be recommended in some cases. The doctor will record the examination and then replay the recording slowly and explain to you the findings of the test.

How long will the procedure take?

It takes 5 to 10 minutes for the spray to work properly. Generally, the procedure itself takes between 5 to15 minutes. Overall, appointments will generally last about 30 to 45 minutes.

Does the procedure hurt?

The doctor sprays both the nose and throat with a solution of local anaesthetic, which makes the area numb. Patients may feel some pressure doing the procedure but will rarely experience discomfort. If you do experience any discomfort during the procedure make the doctor performing the TNO aware.

Can I go home straight away?

The advantage of treatment in the outpatient department is that patients do not require hospital admission and after a few minutes of observation after the procedure they can go home again. .

There are no restrictions to driving or operating machinery after the procedure when it is performed using local anaesthetic.

After the procedure

You will be asked to remain in the department to recover for a short period of time. The nose and throat will remain numb for a while after the procedure which may make you less aware of food / drink temperatures so do not eat or drink anything that is hot for two hours after the procedure. Some patients may also feel a little bloated and pass wind or belch for a while after the procedure, this is normal and the feeling will pass after an hour or two.

You may have some mild discomfort in the throat or nose for a few hours. You can use Paracetamol for this.

Patients using anticoagulation medication (such as warfarin) should resume their use as directed by the GP or anticoagulant clinic.

If you experience any of the following symptoms, call your doctor immediately:

  • Breathing problems such as shortage of breath or rapid breathing
  • Spitting up bright red blood
  • Temperature over 38 degrees
  • Chest pain

If you have any questions, you may contact the ENT department via the hospital switch board on 01223 245151.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151