Is antibiotic prophylaxis recommended in Functional Endoscopic Sinus Surgery (FeSS)?

Antibiotic Prophylaxis in Functional Endoscopic Sinus Surgery (FESS)

Antibiotic prophylaxis is not routinely recommended for FESS, as it is classified as clean-contaminated surgery with expected infection rates below 5%, and high-quality evidence shows that postoperative antibiotics do not improve outcomes or reduce bacterial growth after FESS. 1

Evidence Against Routine Prophylaxis

The strongest direct evidence comes from a randomized controlled trial specifically evaluating postoperative antibiotic use after FESS. This study demonstrated that:

• Postoperative amoxicillin/clavulanate for 3 weeks after FESS did not improve symptom scores, endoscopic findings, or decrease bacterial growth compared to no antibiotics 1
• Both groups showed significant symptom improvement after surgery regardless of antibiotic use 1
• No differences were found in bacterial culture rates or outcomes between antibiotic and control groups at 3 weeks post-FESS 1

Guideline Framework for Clean-Contaminated Surgery

International surgical prophylaxis guidelines provide the broader context for FESS:

• For clean-contaminated ENT surgery with oropharyngeal opening (primarily neoplastic surgery), antibiotic prophylaxis is indicated due to high infection risk (~30%) 2
• However, standard FESS without extensive mucosal resection or oropharyngeal communication does not fall into this high-risk category 2
• When prophylaxis is indicated for ENT procedures, duration should not exceed 24 hours, as this represents prophylaxis rather than curative therapy 2

When Prophylaxis May Be Considered

If you decide to use prophylaxis in specific high-risk FESS cases, follow this protocol:

• Target organisms: Streptococcus, anaerobes, S. aureus, K. pneumoniae, E. coli 2
• First-line agent: Amoxicillin/clavulanate based on local microbial patterns 3
• Timing: Single dose within 30-60 minutes before incision 2, 4
• Duration: Discontinue within 24 hours postoperatively 5, 6
• Do not extend antibiotics beyond 24 hours even if drains are present 5

Microbiology Considerations

Recent microbiological data from CRS patients undergoing FESS shows:

• Most common pathogens: Peptostreptococcus spp., Propionibacterium spp., S. aureus, Pseudomonas spp., Fusobacterium spp., and H. influenzae 3
• Amoxicillin-clavulanic acid demonstrates appropriate coverage based on antibiotic susceptibility patterns 3
• Metronidazole cannot be recommended due to high resistance rates among anaerobic isolates 3

Critical Pitfalls to Avoid

• Do not routinely prescribe postoperative antibiotics for standard FESS, as this provides no benefit and increases antimicrobial resistance 1, 7
• Do not confuse prophylaxis with therapeutic antibiotics—if postoperative infection develops with fever ≥38.5°C, cellulitis >5cm, or systemic signs, this requires treatment, not prophylaxis 8
• Extending antibiotics beyond 24 hours does not reduce infection rates but increases C. difficile infection, antimicrobial resistance, hypersensitivity reactions, and renal failure 5

When Therapeutic Antibiotics Are Indicated

Postoperative antibiotics are only warranted if true surgical site infection develops:

• Clinical signs: Fever, purulent drainage, erythema >5 cm, pain, and swelling 5
• Systemic signs: Temperature ≥38.5°C or pulse ≥100 beats/min 8
• Treatment requires surgical drainage first, with antibiotics added only for systemic involvement 8