Endoscopic sinus surgery
- Procedure
Through the nose and with an endoscope, the natural drainage openings of the sinuses are widened so they can aerate and clear again.
See it in 3D: Maxillary sinus · Ethmoid cells · Sphenoid sinus · Frontal sinus · Cribriform plate
What it is
Functional endoscopic sinus surgery (FESS) is based on Messerklinger's studies of mucociliary transport: if the ostiomeatal complex is opened, the diseased mucosa of the large sinuses can recover on its own. The work is done through the nose with rigid endoscopes, guided by CT and sometimes by navigation. It is the standard for chronic rhinosinusitis that does not respond to medical treatment, and the same route is now used for tumours, cerebrospinal fluid leaks, orbital decompression and pituitary access. Surgery adds to medical treatment; it does not replace it.
Indications and contraindications
- Chronic rhinosinusitis with or without polyps not responding to maximal medical treatment; recurrent acute rhinosinusitis.
- Complications of sinusitis: orbital subperiosteal abscess, mucocele, invasive fungal sinusitis (urgent debridement).
- Allergic fungal sinusitis and fungal ball; antrochoanal polyp.
- Extended: cerebrospinal fluid leak, benign tumours (inverted papilloma) and some malignant ones, orbital and optic nerve decompression, dacryocystorhinostomy, pituitary.
- Refractory posterior epistaxis: endoscopic sphenopalatine artery ligation.
- Relative contraindications: no prior medical treatment, uncorrected bleeding disorder, disease beyond endoscopic reach.
How it is done
- Before: adequate medical treatment, nasal endoscopy and non-contrast (coronal) sinus CT to map the anatomy.
- Decongestion and mucosal infiltration; a rigid endoscope is passed to the middle meatus.
- Uncinectomy: the uncinate process is removed to see the infundibulum and the natural ostium of the maxillary sinus.
- Middle meatal antrostomy: the natural maxillary ostium is widened backwards.
- Anterior ethmoidectomy opening the ethmoid bulla; if needed, the basal lamella is crossed into the posterior ethmoid.
- Sphenoidotomy through the sphenoethmoidal recess and opening of the frontal recess according to the disease.
- The lamina papyracea at the side and the ethmoid roof above are respected; polyps are sent to pathology.
- After: saline nasal irrigation, intranasal corticosteroid, endoscopic cleaning in clinic to prevent adhesions.
Structures of endoscopic sinus surgery and what lies on the other side
| Structure opened | What it drains or allows | Neighbouring risk |
|---|---|---|
| Uncinate process | Opens the infundibulum and the maxillary ostium | Lamina papyracea (orbit) and nasolacrimal duct |
| Maxillary ostium (middle meatus) | Maxillary sinus | Nasolacrimal duct in front, orbit above |
| Bulla and anterior ethmoid cells | Anterior ethmoid and frontal recess | Anterior ethmoidal artery, ethmoid roof |
| Basal lamella and posterior ethmoid | Posterior ethmoid | Optic nerve (Onodi cell) |
| Anterior wall of the sphenoid | Sphenoid sinus | Internal carotid and optic nerve on its lateral wall |
| Frontal recess | Frontal sinus | Lateral lamella of the cribriform plate (cerebrospinal fluid leak) |
Complications
- Orbital: orbital haematoma (a sight-threatening emergency), medial rectus injury with double vision, orbital emphysema.
- Cerebrospinal fluid leak from injury to the cribriform plate or lateral lamella; meningitis.
- Bleeding from the anterior ethmoidal artery or branches of the sphenopalatine artery; rarely from the internal carotid.
- Nasolacrimal duct injury with watering eye (epiphora).
- Optic nerve injury with loss of vision.
- Minor: adhesions (synechiae), frontal recess stenosis, polyp recurrence, reduced sense of smell.
Next step / Initial management
- Before referral: confirm chronic rhinosinusitis (more than 12 weeks, symptoms plus endoscopy or CT) and give medical treatment: saline irrigation and intranasal corticosteroid (fluticasone).
- Use an antibiotic (amoxicillin) only for bacterial exacerbations; short courses of oral corticosteroids for polyps are prescribed by the specialist.
- After surgery: saline irrigation several times a day, no forceful nose-blowing, follow-up for endoscopic cleaning; keep topical corticosteroid long term.
- Refer urgently, the same day, if after surgery there is eye swelling, eye pain, double vision or loss of vision (orbital haematoma), or clear watery discharge, headache with fever or neck stiffness.
- Refer on a routine basis to ENT chronic rhinosinusitis not responding to 2 or 3 months of medical treatment, and with priority one-sided disease (suspected tumour).
Test yourself
Think of the answer, then tap the question to see it.
What is the first step of classic functional endoscopic sinus surgery?
Uncinectomy: removing the uncinate process to open the infundibulum and see the natural ostium of the maxillary sinus in the middle meatus.
One hour after endoscopic sinus surgery, the patient has a proptotic, tense, painful eye with reduced vision. What do you suspect?
Retrobulbar haematoma from injury to the lamina papyracea or the anterior ethmoidal artery: an emergency needing immediate decompression (lateral canthotomy and cantholysis).
Which area of the nasal roof carries the highest risk of cerebrospinal fluid leak in endoscopic surgery?
The lateral lamella of the cribriform plate, the thinnest bone of the skull base, especially when the olfactory fossa is deep.
Which physiological principle underlies functional endoscopic sinus surgery?
Messerklinger's mucociliary transport towards the natural ostia: opening the ostiomeatal complex lets the mucosa of the large sinuses recover.
Elsewhere in DurgiPedia
Connections
See it in 3D5
The structures of Durgical's 3D anatomy where it is found.
In Pharmacology3
Educational content; it does not replace a medical assessment and is not a clinical instruction. For a real case, follow current guidelines and specialist advice.
Sources: Endoscopic Sinus Surgery (StatPearls) (StatPearls Publishing, NCBI Bookshelf, 2022); Sinusitis (MedlinePlus, U.S. National Library of Medicine, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.