What is the significance of grading in Functional Endoscopic Sinus Surgery (FESS)?

The Significance of Grading in Functional Endoscopic Sinus Surgery (FESS)

Grading in FESS is essential for standardized assessment, treatment planning, and monitoring treatment response in patients with chronic rhinosinusitis, directly impacting surgical outcomes and patient morbidity and mortality. 1

Grading Systems in FESS

• The most commonly used standardized endoscopic scoring systems include the Lund-Kennedy scale and the 0-4 polyp grading scale, which evaluate polyp size and extent within the nasal cavity 1
• The 0-4 polyp grading scale classifies polyps as: Grade 0 (no visible polyps), Grade 1 (small polyps in middle meatus), Grade 2 (polyps reaching below lower border of middle turbinate), and Grade 4 (large polyps causing complete obstruction of inferior nasal cavity) 1
• The Lund-Kennedy endoscopic scoring system evaluates multiple parameters including polyps (0-2), edema (0-2), discharge (0-2), scarring/adhesions (0-2), and crusting (0-2), with total scores ranging from 0-12 1

Clinical Significance of Grading

Surgical Decision-Making

• Grading helps determine the appropriate extent of surgery needed - when sinuses involve polyps, osteitis, bony erosion, or fungal disease, surgeons should perform full exposure of the sinus cavity and removal of diseased tissue, not just balloon or manual ostial dilation 2
• The extent of disease identified through grading systems directly influences whether minimal, full, extended, or radical FESS approaches are required 2
• Proper grading identifies anatomical variations that may contribute to disease recurrence and need for revision surgery, such as persistent frontoethmoidal cells (found in 81.2% of revision cases) 3

Treatment Outcomes

• Grading helps predict surgical outcomes - studies show that higher grades of disease severity correlate with lower control rates after surgery 2
• In a 12-year follow-up study, only 16% of patients achieved complete disease control after FESS, with 44% partially controlled and 40% uncontrolled, highlighting the importance of accurate preoperative grading 2
• Patients with higher-grade disease (extensive polyps, osteitis) are more likely to require revision surgery, with approximately 10-15% of FESS patients eventually needing revision procedures 3

Post-Surgical Monitoring

• Grading systems provide objective measures to monitor disease progression and treatment response over time 2
• The minimally important clinical difference for the modified Lund-Kennedy endoscopy scale is approximately 3 points on the 0-12 scale, helping clinicians determine meaningful changes after intervention 1
• Surgeons should routinely follow up to assess and document outcomes of sinus surgery using standardized grading systems 2

Practical Application of Grading

• Nasal endoscopy should be performed after applying topical decongestant and anesthetic to the nasal mucosa, examining key areas including the nasal cavity, middle meatus, uncinate process, and sphenoethmoidal recess 1
• To differentiate polyps from severely edematous mucosa, a topical vasoconstrictor can be applied - polyps will not shrink, unlike edematous mucosa 1
• Polyp scores should be assessed bilaterally, with each side scored separately, then combined for a total score 1
• CT scanning should complement endoscopic grading for surgical planning, especially for unilateral polyps or when endoscopic evaluation is inadequate 1

Impact on Patient Outcomes

• Proper grading correlates with patient-reported outcome measures - studies show average SNOT-22 scores of 9.7,22.2, and 44.8 for controlled, partly controlled, and uncontrolled disease respectively 2
• VAS total nasal symptom scores correlate with disease control categories (0.8,2.7, and 5.7 for controlled, partly controlled, and uncontrolled respectively) 2
• Accurate grading helps identify patients at higher risk for complications or treatment failure, such as those with aspirin intolerance or requiring revision surgery 2

Pitfalls and Caveats

• Relying solely on symptoms without endoscopic grading may lead to inadequate surgical planning - in 95.1% of cases, nasal endoscopy findings align with symptom-based assessments, but the 4.9% discrepancy can be clinically significant 2
• Failure to properly grade and address anatomical variations during primary surgery is a major factor in surgical failure, with persistent frontoethmoidal cells, anterior and posterior ethmoid cells being the most common findings in revision cases 3
• Overreliance on minimal approaches for higher-grade disease can lead to increased need for revision surgery and prolonged patient morbidity 2