Functional endoscopic sinus surgery (FESS) is a minimally invasive surgical procedure that opens up sinus air cells and sinus ostia (openings) with an endoscope.
The use of FESS as a sinus surgical method has now become widely accepted and the term "functional" is meant to distinguish this type of endoscopic surgery from non-endoscopic, more conventional sinus surgery procedures.
Description of Functional endoscopic sinus surgery (FESS)
After inducing adequate vasoconstriction with cocaine or ephedrine
, the surgeon locates the middle turbinate, the most important landmark for the FESS procedure. On the side of the nose at the level of the middle turbinate lies the uncinate process, which the surgeon removes. The surgeon opens the back ethmoid air cells, to allow better ventilation, but leaves the bone covered with the mucous membrane. Following this step, the ostium located near the jaw is checked for obstruction and, if necessary, opened with a middle meatal antrostomy. This surgical procedure often greatly improves the function of the osteomeatal complex and provides better ventilation of the sinuses.
Purpose of Functional endoscopic sinus surgery (FESS)
The purpose of FESS is to restore normal drainage of the sinuses. Normal function of the sinuses requires ventilation through the ostia (mouth-like opening) and is facilitated by a mucociliary transport process that maintains a constant flow of mucus out of the sinuses. All sinuses need ventilation to prevent infection and inflammation, a condition known as sinusitis. In healthy individuals, sinus ventilation occurs through the ostia into the nose. The sinuses open into the middle meatus (curved passage in each nasal cavity) under the middle turbinate (thin, bony process that is the lower portion of the ethmoid bone in each nasal cavity), which together are known as the osteomeatal complex, the key area of the nose. The hair-like cilia direct the flow of mucus toward the ostia.
develops when there is a problem in the area where the maxillary and frontal sinuses meet near the nose or, occasionally, by dental infection. When sinusitis occurs, the cilia work less efficiently, preventing the flow of mucus. The mucous membranes of the sinuses become engorged, resulting in ostia closure. Poor ventilation and accumulation of mucus then produce the conditions required for bacterial infection.
Preparation for Functional endoscopic sinus surgery (FESS)
As with many diseases, the history of a patient with sinusitis represents a key part of the preoperative evaluation. Before considering FESS, the ear, nose and throat (ENT) specialist
will proceed with a thorough diagnostic examination. The development of such diagnostic tools as the fiberoptic endoscope and CT scanning has greatly improved the treatment of sinus disease
. The fiberoptic endoscope is used to examine the nose and all its recesses thoroughly. The specific features the physician must examine and evaluate are the middle turbinate and the middle meatus, any anatomic obstruction, and the presence of pus and nasal polyps
CT scanning can also be used to identify the diseased areas, a process that is required for planning the surgery. It shows the extent of the affected sinuses, as well as any abnormalities that may make a patient more susceptible to sinusitis.
FESS is usually performed under local anaesthesia with intravenous sedation on an outpatient basis with patients going home one to two hours after surgery. It usually does not cause facial swelling or bruising, and does not generally require nasal packing.
Risks associated with Functional endoscopic sinus surgery (FESS)
The most serious risk associated with FESS is blindness
resulting from damage to the optic nerve. The chances of this complication occurring, however, are extremely low. Cerebrospinal fluid leak represents the most common major complication of FESS. The leak is usually recognized at the time of surgery and can easily be repaired. Other less serious and rare complications includes orbital hematoma and nasolacrimal duct stenosis. All of these complications are also associated with conventional sinus surgery and not only with FESS.
Normal results of Functional endoscopic sinus surgery (FESS)
The FESS procedure is considered successful if the patient's sinusitis is resolved. Nasal obstruction and facial pain are usually relieved. The outcome has been compared with that of the Caldwell-Luc procedure and, although both methods are considered effective, there is a strong patient preference for FESS. The extent of the disease before surgery
dictates the outcome, with the best results obtained in patients with limited nasal sinusitis.