Functional Endoscopic Sinus Surgery (FESS)
1. Definition: Functional Endoscopic Sinus Surgery (FESS) is a minimally invasive surgical technique used to restore proper ventilation and drainage of the paranasal sinuses. It is performed using a rigid endoscope inserted through the nose, allowing the surgeon to visualize and enlarge the natural drainage pathways of the sinuses, most importantly the Ostio-Meatal Complex (OMC), while preserving as much normal, healthy mucosa as possible.
2. Indications for Performing the Operation
3. Brief Description of the Main Stages - https://youtu.be/R3i1P6_ARvI?si=UvZUFe6ZW6jskMtu
FESS is typically performed under general anesthesia with the aid of image guidance systems (using a pre-operative CT scan) for complex cases or revision surgery to enhance surgical safety. The operation is highly site-specific, but the main goal is to clear the OMC.
I. Preparation and Anesthesia
- Local Anesthesia/Vasoconstriction: The nasal cavity is packed with cottonoid pledgets soaked in a topical vasoconstrictor mixed with local anesthetic (e.g., Lidocaine). This reduces bleeding and provides mucosal shrinkage.
- Injectable Anesthesia: Anesthetic is often injected into the middle turbinate and surrounding areas (e.g., greater palatine foramen) for improved hemostasis and pain control.
II. Endoscopic Assessment and Initial Steps
- Endoscopy: The nasal cavity is thoroughly inspected using a rigid endoscope (usually 0°and 30°).
- Uncinectomy (Uncinate Process Removal): This is often the first formal step of the procedure. This opens the middle meatus and provides access to the anterior ethmoid and maxillary sinus ostia.
III. Ethmoidectomy
- Anterior Ethmoidectomy: Removal of the anterior ethmoid air cells to widely open the OMC.
- Posterior Ethmoidectomy: If disease extends posteriorly, the posterior ethmoid cells are removed. This step requires extreme caution due to the proximity of the skull base (above) and the optic nerve(posteriorly).
IV. Maxillary Sinus Ostium Enlargement (Middle Meatal Antrostomy)
- Once the uncinate process is removed, the natural ostium of the maxillary sinus is visualized.
- The ostium is gently enlarged (antrostomy) posteriorly and inferiorly to create a wide, functional opening.
V. Frontal and Sphenoid Sinus Exploration
- Frontal Sinusotomy: Access to the frontal recess, often by removing ethmoid cells and sometimes the anterior attachment of the middle turbinate. Draf procedures are reserved for severely diseased frontal sinus obstruction.
- Sphenoid Sinusotomy: The sphenoid ostium, which opens into the sphenoethmoidal recess, is identified and opened. This is critical for severe sphenoid disease or to access the skull base.