What are the indications and steps for Functional Endoscopic Sinus Surgery (FESS)?

Functional Endoscopic Sinus Surgery (FESS): Indications and Steps

Functional endoscopic sinus surgery (FESS) is indicated for patients with chronic rhinosinusitis who have failed appropriate medical management, have persistent symptoms despite 8-12 weeks of medical therapy, and when anticipated benefits exceed nonsurgical management alone. 1

Indications for FESS

Primary Indications:

• Chronic rhinosinusitis (CRS) refractory to medical treatment 2, 1
• CRS with nasal polyps unresponsive to medical therapy 1
• Fungal sinusitis 2
• Recurrent acute rhinosinusitis (2-3 episodes per year despite appropriate treatment) 1
• Complications of acute sinusitis (orbital or intracranial involvement) 2, 1
• Anatomic abnormalities contributing to sinus obstruction 2

Medical Management Before Considering Surgery:

• Antibiotics (amoxicillin-clavulanate or high-dose amoxicillin) 1
• Intranasal corticosteroids 1
• Nasal saline irrigations 1
• Treatment duration of at least 8-12 weeks 1

Diagnostic Criteria Supporting Surgical Intervention:

• Objective evidence of disease on CT scan 1
• Endoscopic evidence of sinusitis 1
• Symptoms persisting >12 weeks 2, 1

Steps of FESS Procedure

Preoperative Assessment:

1. Coronal CT scan (gold standard) with cuts through the ostiomeatal complex 1
2. Nasal endoscopy to assess extent of disease 2
3. Evaluation of comorbidities (asthma, allergies, GERD) 1

Surgical Procedure:

1. Patient Positioning and Anesthesia:

   • General anesthesia (most common) or local anesthesia 3
   • Patient in semi-recumbent position

2. Endoscopic Examination:

   • Initial endoscopic assessment of nasal cavity
   • Identification of key landmarks (middle turbinate, uncinate process)

3. Surgical Steps:

   • Uncinectomy: Removal of the uncinate process to expose the natural maxillary sinus ostium
   • Middle meatal antrostomy: Enlargement of the natural maxillary sinus ostium
   • Anterior ethmoidectomy: Removal of diseased ethmoid air cells
   • Posterior ethmoidectomy: If disease extends to posterior ethmoids
   • Frontal sinusotomy: Opening the frontal recess if frontal sinusitis is present
   • Sphenoidotomy: Opening the sphenoid sinus if disease is present 1

4. Disease-Specific Modifications:

   • Removal of polyps if present
   • Partial middle turbinectomy when indicated (safe procedure) 4
   • Removal of fungal material if fungal sinusitis is present 2

5. Hemostasis and Closure:

   • Careful hemostasis
   • Placement of absorbable packing if needed

Extent of Surgery:

• Tailored to the extent of disease identified on preoperative CT and intraoperative findings 2
• Limited to affected sinuses rather than routine complete ethmoidectomy 2
• Conservative approach recommended for primary surgery 2

Postoperative Management

1. Immediate Care:

   • Most procedures (>84%) can be performed on an outpatient basis 4
   • Pain control with appropriate analgesics

2. Follow-up Care:

   • Endoscopic debridement as needed
   • Continued medical therapy (intranasal corticosteroids, saline irrigations) 1
   • Assessment between 3-12 months post-surgery 1

3. Outcomes Assessment:

   • Symptom relief
   • Quality of life improvement
   • Endoscopic evaluation of healing 1

Complications

Major Complications (rare, <0.5%):

• Orbital injury
• Cerebrospinal fluid leak
• Intracranial injury 2, 4

Minor Complications (approximately 8%):

• Bleeding
• Synechiae formation
• Infection 4

Expected Outcomes

• 88% of patients symptom-free or improved with mean follow-up of 17 months 4
• Approximately 41.5% may still require some medical therapy 4
• Revision surgery needed in approximately 10% within 3 years 2

Pitfalls and Caveats

• Smoking significantly worsens long-term outcomes; consider carefully in patients who continue to smoke 2
• FESS should be reserved for patients who do not respond to appropriate medical treatment 2
• Extended surgery does not yield better results than limited procedures in primary cases 2
• Failure to recognize complications can have serious consequences 1
• Patients with immunodeficiencies, cystic fibrosis, or Wegener's granulomatosis may require specialized approaches 1

FESS has revolutionized the surgical approach to chronic rhinosinusitis by focusing on the functional restoration of sinus ventilation and drainage rather than radical sinus procedures, with high success rates and minimal morbidity when performed by experienced surgeons.