Functional Endoscopic Sinus Surgery


Functional endoscopic sinus surgery (FESS) aims to improve ventilation and drainage of the paranasal sinuses by correcting anatomic problems in the osteomeatal complex and other sinus drainage portals in order to establish a physiologic pathway for mucociliary clearance.

Indications for Surgery

  • Chronic rhinosinusitis with persistent symptoms despite maximal medical therapy
  • Recurrent acute rhinosinusitis with persistent symptoms despite maximal medical therapy
  • Acute-on-chronic rhinosinusitis with persistent symptoms despite maximal medical therapy
  • Invasive or allergic fungal rhinosinusitis
  • Obstructive sinonasal polyposis
  • Mucocele
  • Mycetoma/fungal ball
  • Cerebrospinal fluid leaks and meningoencephaloceles of the anterior cranial fossa
  • Orbital extension of infectious/inflammatory sinus disease
  • Orbital decompression, most commonly for thyroid-associated orbitopathy
  • Foreign body removal
  • Sinonasal tumors (if amenable to endoscopic approach)

Contraindications to Surgery

  • Medical comorbidities that would preclude surgical or anesthesia risk
  • Surgery is not indicated in asymptomatic patients, even if radiographic or endoscopic findings suggesting inflammatory disease are present

Pre-Operative Evaluation

  • Sinus CT, with intraoperative image guidance navigation protocol for some skull base or revision cases
  • MRI of the orbits is indicated for sinonasal tumors and conditions that extend to, or incorporate, the orbits or skull base
  • Some physicians recommend pre-operative antibiotics and steroids to minimize inflammation at time of surgery


General, via endotracheal tube or laryngeal mask airway

Surgical Technique

  1. The patient is placed supine on the operating table and general anesthesia is induced. Pledgets with topical decongestant are placed in the nares.
  2. Bilateral transoral sphenopalatine nerve blocks are performed by injecting the greater palatine foramina with 1% lidocaine.
  3. The image guidance system, if used, is registered to the patient and calibrated for intraoperative navigation.
  4. Both nasal cavities are examined with the 0-degree rigid nasal endoscope, and local anesthetic with decongestant is injected along the middle turbinate and lateral nasal walls.
  5. The middle turbinate is medialized using a Freer elevator, and the middle meatus is entered.
  6. The uncinate is carefully identified, reflected, and resected in an inferior-to-superior fashion, revealing the natural ostium of the maxillary sinus.
  7. The microdebrider may be used to remove tissue at this site to better identify the natural ostium and complete the antrostomy.
  8. To perform an anterior ethmoidectomy, the ethmoid bulla is identified and removed with a dissecting instrument. If performing a total ethmoidectomy, the basal lamella of the middle turbinate is traversed and diseased posterior ethmoid cells and partitions are removed until the superior turbinate is encountered. Care is taken not to enter the orbit and skull base by using anatomical landmarks in combination with the CT as guidance.
  9. If required, a total ethmoidectomy is completed in a posterior-to-anterior fashion along the skull base using angled endoscopes to completely but delicately remove remnant ethmoid partitions and diseased tissue. The location of the anterior ethmoid artery must be appreciated as, if cut, it may retract into the orbit and the resulting hematoma may compress the optic nerve causing loss of vision.
  10. The sphenoid ostia are located just medial to the superior turbinates, and sphenoidotomies, when required, are made and widened.This procedure often reveals additional landmarks within the sphenoid, including the posterior skull base and impressions of the carotid artery, optic nerves, and sella turcica (which contains the pituitary gland).
  11. The frontal sinus and frontal recess that leads into the nose are often complex spaces due to the wide anatomical variability in this region. In the most straightforward dissection of the frontal outflow tract, the frontal recess can be gently explored with a curette in the space behind the Agger nasi cell and face of the ethmoid bulla, and possibly cannulated smoothly with a malleable suction. Often, angled 45- or 70-degree endoscopes are utilized for this dissection.
  12. At the end of the case, some surgeons may place hemostatic biosealants, spacers, or sinus stents in the nasal cavities to minimize postoperative hemorrhage and scar tissue formation within the paranasal sinuses. Splints or quilting stitches may also be placed if a turbinate or septal procedure was performed in the same setting.
  13. Upon completion of the case, an orogastric tube is passed to suction the oropharynx and stomach, and care of the patient is returned to the anesthesiologist for extubation and recovery.

Post-Operative Care

  • FESS is usually performed on an elective, outpatient basis.
  • A visual and mental status examination should be performed prior to discharge.
  • Patients are discharged with nasal saline sprays and a short course of nasal decongestant, as nasal obstruction due to swelling and blockage by crusting or clots is often present in the first few weeks.
  • Antibiotics and oral steroids are used in selected cases.
  • Patients are instructed to avoid strenuous activity and nose blowing.
  • Patients who use continuous positive airway pressure (CPAP) devices for obstructive sleep apnea are generally advised to avoid using them for the first post-operative week.
  • The first post-operative follow-up office visit should occur within 1-2 weeks of surgery; at this time, any crusts, clots, and debris obstructing the sinus ostia are gently debrided.


  • Epistaxis
  • Hyposmia or anosmia
  • Adhesions or synechiae
  • Mucocele formation
  • Headache and/or facial pain/pressure
  • Dental sensitivity, especially over upper alveolar ridge dentition
  • Epiphora (excessive tearing) due to injury to the nasolacrimal duct
  • Swelling of the eye indicates a possible hematoma within the orbit due to injury of the anterior ethmoid artery. This is an emergency requiring orbital decompression as visual loss may rapidly result.