Flexible fibreoptic nasolaryngoscopy (FOL)

Information on flexible fibreoptic nasolaryngoscopy updated 18 January 2016

This out-patient examination procedure may also be referred to as

  • Fibreoptic nasendoscopy – FNE
  • Fibreoptic laryngoscopy or laryngoscope
  • Nasal laryngoscopy or Nasal laryngoscope
  • Rhinolaryngoscopy or Rhino-laryngoscope
  • Video laryngoscope (if done with a monitor)
  • Laryngeal stroboscopy (if done with a strobe light source)
  • Vocal cord check

Flexible fibreoptic nasolaryngoscopy is carried out to diagnose conditions of the nose and throat. Typical symptoms to be investigated with flexible fibreoptic nasolarynggoscopy include

  • Blocked nose
  • Catarrh
  • Post nasal drip
  • Sore throat
  • Hoarse voice
  • Difficulty swallowing
  • Feeling of a lump in the throat
  • Cough
  • Lump in the neck

A flexible laryngoscope

  • allows close up view of inaccesible areas of nose and throat
  • the flexible instrument allows us to see around corners
  • the vocal cords can be seen in motion
  • very bright illumination helps diagnose conditions of the nose, nasopharynx, larynx and hypopharynx accurately

Having flexible fibreoptic nasolaryngoscopy: What to expect

Before the procedure
local anaesthetic spray applied to nose before flexible fibreoptic nasolaryngoscopy

  • you will normally receive a local anaesthetic spray immediately beforehand to reduce any tendency to gag
  • the local anaesthetic will taste bitter and you may imagine your throat is swelling up. Don’t panic, that is just the local anaesthetic working
  • it is also possible to undergo the examination without any local anaesthetic spray – but it may be a little painful in the nose, and you may tend to gag

During the procedureFlexible fibreoptic nasolaryngoscopy: ENT Specialist passing flexible endoscopic camera through the seated patient's nose, while nurse supports the head from behind

  • the instrument will be passed gently through your nose & into your throat
  • sit still and breathe through the mouth, the nurse will support you
  • you may be asked to sing a high pitched note, maybe to cough, and to puff out your cheeks – don’t worry, you will be told exactly what to do during the procedure

After the procedure

  • don’t get up until the nurse says so – you may be dizzy
  • Surgeon's view of laryngitis as seen by flexible fibreoptic nasolaryngoscopywe will normally tell you the result of the examination straight away
  • you should not eat or drink till the local anaesthetic has worn off – about an hour
  • you should be ok to drive after an hour

What other options are there?

Indirect laryngoscopy (mirror examination of voice box)

Until we had the flexible scopes, the standard way of examining the larynx was to use a mirror held in the mouth, with the patient’s tongue pulled out. This technique is known as indirect laryngoscopy. Indirect laryngoscopy (mirror examination) can still be done, but it requires considerable skill and practice. In those parts of the world where the flexible fibreoptic laryngoscope is readily available, indirect laryngoscopy using a mirror is a dying art. Most patients find it less tolerable than the scope, and the view for the doctor is not so good.

Direct laryngoscopy under general anaesthesia

Before we had the flexible fibreoptic laryngoscope, many patients were subjected to a general anaesthetic for a direct laryngoscopy, just because it was not possible to get a good enough view with the mirror. It is still sometimes necessary to carry out a direct laryngoscopy under a general anaesthetic for the rare patient who cannot tolerate the flexible laryngoscope. It may also be necessary to have a general anaesthetic where it is necessary to take a biopsy from something found with the flexible scope.