What is it?

FESS is an abbreviation of ‘functional endoscopic sinus surgery’. This procedure involves widening the natural openings to the sinuses. Its objective is to improve sinus ventilation and drainage of mucus from the sinuses. The procedure is an endoscopic one, which means that a camera is used to look directly into the sinuses through the nostrils and to perform the procedure. Therefore, no external incisions are required to create access to the sinuses. So the appearance of the nose will not change.


This procedure can be performed for problems including:

The procedure

The procedure is performed under general anaesthetic. Fragments of the mucous membrane and bone are removed to widen the natural openings of the sinuses. At the end of the procedure, the decision may be taken to place tampons or ribbon gauze in the nose to stop bleeding and to prevent the widened sinuses from closing again due to scar tissue. These ribbon gauzes remain in place for one to a few days. They will be removed from the nose at the consultation.

Any procedure carries the risk of complications, but fortunately these are very rare. Possible complications of a sinus procedure are related to the structures in and around the nose, or to the risks associated with anaesthesia. Below are possible complications (this list is not an exhaustive):

  • nose: nosebleed, affected sense of smell
  • brain: cerebrospinal fluid leak, bleeding, infection
  • eye: bleeding, infection, sight loss, double vision
  • allergic reaction

After the procedure

After the procedure, the nose must be irrigated multiple days a day with physiological saline to keep the sinuses clean. This is because during the healing process, clots, mucus and crusts will form. Thorough irrigation of the nose is essential for proper and fast wound healing. Additionally, medication such as painkillers, antibiotics, nasal sprays and nasal ointments may be prescribed.

In the days after the procedure, you may experience the following:

  • headache
  • nasal congestion
  • mucus
  • crust formation
  • bloody nasal discharge

A few follow-up appointments will be planned for the weeks following the procedure to check up on wound healing and, if necessary, to clean the nose.

Centres and specialist areas

Ear, nose, and throat diseases

Latest publication date: 01/04/2021
Supervising author: Dr Vermeiren Judith