Part I: Functional Endoscopic Sinus Surgery

Understanding Functional Endoscopic Sinus Surgery (FESS)
Despite the availability of several different types of procedures in the treatment of recurrent acute and chronic sinusitis, the overwhelming and most common operation is known as a functional endoscopic sinus surgery, or “FESS”, for short). Simply put, in performing a FESS operation, surgeons use microinstruments and a nasal endoscope attached to a fiber optic lens into through the nostrils to assist in the removal of obstructive and infected sinus bone and tissue.
Prior to the advent of the FESS procedure, surgeons were only well-versed in treating infections in the maxillary paranasal sinuses. If a fungus or bacteria occurred in the ethmoid, frontal, or sphenoid sinuses, patients usually experienced only a partial improvement of their chronic sinusitis. Doctors seldom knew which sinus was infected, since the sinus CAT scan was not yet in wide use, affecting the success rate dramatically. Traditional sinus surgery had not yet been perfected, so patients were left with scars and only a marginal improvement in their sinusitis.
The FESS procedure is thus considered the mainstay for patients seeking effective results in battling sinusitis and nasal polyps, and is the go-to procedure for not only chronic sinusitis, but also for recurrent acute sinusitis and sinus problems resulting from bacterial and/or fungal infection.
Dr. Bennett uses the FESS for most of his sinus procedures due to its outstanding success rate coupled with its minimally invasive character. It is an outstanding example of how today’s modern medical technology has made a complex condition much more treatable.

Popularity and Efficacy of the FESS
The nasal endoscope was introduced in the 1950’s which allowed the development of the FESS procedure. Developed during the 1980’s the FESS effectively transformed and modernized the surgical treatment of chronic sinusitis. This is partly due to the fact that it permits the surgeon to access all the paranasal sinuses using this method, including:
- Frontal sinuses (located in the forehead)
- Maxillary sinuses (located in the cheeks)
- Ethmoid sinuses (located between the eyes)
- Sphenoid sinuses (located at the back of the nasal cavity in the middle of the head)
Currently, over 200,000 patients per year undergo this type of surgery, making it overwhelmingly the most widespread and common type of sinus surgery. This is likely due to its high success rate, as studies published in medical journals report a success rate between 80% to as high as 98% on average. Note that revision FESS procedures also exist, with similar success rates.
How is Functional Endoscopic Sinus Surgery Performed?
In a FESS procedure, the primary instrument used by your surgeon is an endoscope. An endoscope is a long, slender medical instrument used to examine the interior of the paranasal sinuses and nasal cavity. Endoscopes serve several important functions:
First, endoscopes improve intranasal visibility using high quality fiber-optics. Secondly, a camera attached to the endoscope will allow the surgeon more detail by televising a magnified image onto a larger screen in the operating room. Finally, endoscopes permit the surgeon to carefully and accurately remove tissue in the infected sinuses to reestablish more normal sinus drainage.
Thus, in a typical FESS operation, the surgeon inserts the endoscope into the nostrils, views an enlarged image of the tissue in the paranasal sinuses and nasal cavity more closely, locates and subsequently opens the affected areas as needed. Tissue removed from the nose is generally sent to a pathologist for examination.
Image guidance can be used as a tool to assist in a FESS. Image guidance may be used if there are nasal polyps, frontal or sphenoid sinus disease, or if it is a revision sinus surgery. While using image guidance, the instruments used will show the sinus CAT scan in 3 views at the location of the instrument inside the nose. This can be compared to the live image on the monitor to provide additonal information about the sinuses.
How is each Sinus treated by Functional Endoscopic Sinus Surgery ?
The maxillary sinus drains through an opening near its top called the maxillary ostia. When this ostia is obstructed the maxillary sinus can have acute or chronic sinus infections. The opening to the maxillary sinus on each side is covered by a flap of bone and mucosa called an ‘uncinate’. Removal of the uncinate and enlargement of the maxillary sinus opening can help establish normal drainage and improved function of the sinus.
Ethmoid sinuses can be thought of as small bony sacs (cells) covered with nasal mucosa. Each ethmoid cell has a tiny hole that ventilates it and there are 5 to10 ethmoid sinus cells on each side. Removal of the bony walls of the ethmoids and enlargement of the openings will prevent the ethmoids from becoming obstructed and assist in drainage. Ethmoids near the frontal and maxillary sinuses can also contribute to obstruction of those sinuses.
The frontal sinuses are formed from the anterior ethmoids expanding into the frontal bones. They are rarely symmetric between the left and the right sides. They have narrow openings which can become obstructed with bone or swollen tissue. Opening of the frontal sinuses can reestablish drainage and improve function. Because the frontal sinuses are so narrow, they require delicate surgical care and are still prone to re-stenosing.
The sphenoid sinuses are located at the back of the nose in the middle of the head. They drain at their midportion into the back ofth nose. They are the least commonly infected sinuses. Opening the front wall of the sphenoid sinus can allow for the sinus to drain normally.
Additional Procedures with Functional Endoscopic Sinus Surgery.
Sometimes, surgeons will also perform additional operations depending upon the patient’s needs. Common procedures often coupled with a FESS surgery include:

Days and weeks leading up to FESS surgery
(1) Medications: Your surgeon will advise whether you should discontinue certain medications you are currently taking leading up to surgery, to reduce post-operative nosebleeds. If bleeding occurs, Afrin or nasal packing may be used to stop the bleeding. Common medications that induce bleeding, and must be discontinued, with approval of your primary care physician, include:
- Aspirin and Ibuprophen
- Prescription blood thinners (i.e. Coumadin and Plavix)
- Vitamin E
- Certain diet pills
- Herbal remedies
Patients with high blood pressure also risk the chance of a severe nosebleed, and must take special care to have blood pressure under excellent control before surgery. These patients also need to stop any medications that will increase the likelihood of additional bleeding after surgery.
(2) Smoking: It is crucial to stop smoking at least two weeks prior to the surgery. Smoking not only interrupts the natural healing process of the sinuses, but also serves as an irritant to the nasal cavity. Smoking decreases the blood flow to the nose which can inhibit healing factors from getting to the recovering nasal tissue.
As an aside, Dr. Bennett reminds patients that smoking in general is harmful to anyone with a history of sinusitis or sinus problems, due its impact on an individual’s respiratory system. The harmful ingredients contained in cigarette smoke increase congestion, and contribute to nasal drainage problems. Cigarettes have been reported to also destroy the delicate “cilia” in the mucus membranes of the sinus, which act as an air filtration system – cleaning out the dirt and bacteria from the nose to decrease sinus infections and inflammation. Although the cilia have the capacity to regenerate, this is only possibly if one stops smoking.
Cigarette smoke and second-hand smoke also contribute to a host of various other severe medical and health issues, including respiratory and cardiovascular diseases that are separate and apart from the sinuses.
(3) Drinking and Eating: Patients should take extra care not to drink or eat anything (including water) starting at midnight on the night before the sinus surgery. This is for anesthesia purposes. This reduces the likelihood of nausea and vomiting once surgery is complete and you are transferred to the recovery room.
What happens immediately after surgery?
After a FESS procedure, you will most likely experience some sinus congestion and sinus headaches. Oozing of blood from the nose is common for a few days to weeks after FESS. It is critical to allow your sinuses and body to heal following surgery, so it is recommended that you rest for several days to a week, ideally taking time off from work, especially if you have a physically rigorous profession.
FESS operations are performed in one to two hours for most patients, and following surgery, if you are in good health, you are usually permitted to leave the surgery center the same day. Unlike traditional sinus surgery, nasal packing is rarely needed, depending upon the severity of the infection.
If you chose to undergo a FESS procedure, keep in mind that it may take several months for you to reap the full benefits of the surgery. The sinuses may till become infected during the healing process and you should not overexert yourself too soon after surgery even if you feel great. Most patients report a rapid relief of sinus pain, however it is likely that it will take a bit longer for your sinuses to completely heal and experience a new, healthy-breathing lifestyle.

Learn more about choosing the right sinus surgery with the next types in the following guides:
Guide to choosing the right sinus surgery, balloon sinus surgery.
Guide to choosing the right sinus surgery, traditional sinus surgery.