[1] Utilizing Hopkins' rod optic system, Walter Messenklinger visualized, recorded, and mapped the anatomy of the paranasal sinuses and the lateral nasal walls - specifically, the mucociliary routes - in cadavers.

[4] Heinz Stammberger,[5] a head and neck surgeon who worked at the University of Graz with Messerklinger was captivated by the technique and the implications for pathophysiology and treatment of sinus disease.

[14] In cases that have not responded to corticosteroid treatment, FESS can be used to decompress the orbital region by removing the ethmoid air cells and lamina papyracea.

[1][citation needed] The endoscopic approach to FESS is a less invasive method than open sinus surgery, which allows patients to be more comfortable during and after the procedure.

Entering the surgical field via the nose, rather than through an incision in the mouth as in the previous Caldwell-Luc method, decreases risk of damaging nerves which innervate the teeth.

It has been suggested that one of the main objectives in FESS surgery is to allow for the introduction of local therapeutic agents (such as steroids) to the sinuses.

Research has shown that a special modification of the nozzle of the nasal spray in patients who had FESS allows for better delivery of local therapeutic agents into the ethmoid sinuses.

[15] Functional Endoscopic Sinus Surgery is considered a success if most of the symptoms, including nasal obstruction, sleep quality, olfaction and facial pain, are resolved after a 1–2 month postoperative healing period.

[8][16][17] Reviews of FESS as a method for treating chronic rhinosinusitis have shown that a majority of patients report increased quality of life after undergoing surgery.

Other risks of surgery include infection, bleeding, double vision usually lasting a few hours, numbness of the front teeth, orbital hematoma, decreased sense of smell, and blindness.

[8] A Cochrane review in 2006 based on three randomized control trials concluded that FESS has not been shown to provide significantly better results than medical treatment for chronic rhinosinusitis.

[23] Another Cochrane review looked at postoperative care of patients after FESS using debridement (removal of blood clots, crusts, and secretions from the nasal and sinus cavities under local anaesthetic), but the evidence from the available clinical trials was uncertain.