The microbiology of recurrent rhinosinusitis after endoscopic sinus surgery.

OBJECTIVE To determine the microbiology of recurrent sinus infections occurring in patients after endoscopic sinus surgery (ESS). DESIGN Retrospective review of sinus cultures obtained over a 4-year period from a consecutive series of patients who underwent ESS. SETTING An academic general otolaryngology practice. RESULTS A total of 290 cultures were performed in 125 patients after ESS. The female-male ratio of cultures was 2.5:1 with an average patient age of 47.3 years. This group of patients represents 14.5% of 860 patients who underwent ESS during the same period. A total of 65 patients had 1 culture performed, and 60 patients had multiple cultures. Of the 290 culture specimens, 87 (30.0%) demonstrated no growth. Gram-positive cocci predominated, accounting for 37.9% of culture results. Gram-negative rods constituted 14.8% of the isolates. Of the cultures yielding gram-negative rods, 90.7% occurred in patients who had multiple cultures (P = .03). Fungal forms were cultured in 1.7% of the specimens. None of the Streptococcus pneumoniae isolates demonstrated penicillin-based resistance. The percentages of beta-lactamase-producing strains for Haemophilus influenzae and Branhamella (Moraxella) catarrhalis were 45.4% and 81.8%, respectively. Staphylococcal species also exhibited significant antibiotic resistance patterns, but no statistical association with multiple cultures was noted (P = .23). CONCLUSIONS A wide range of bacteria may be present in the infected post-ESS sinus cavity, with a considerable population of gram-negative organisms, including Pseudomonas species. Beta-Lactamase-producing organisms continue to be prevalent in postoperative sinus infections. Culture and sensitivity analyses of pathologic secretions may identify drug-resistant organisms or organisms related to difficult-to-treat infections in exacerbations of chronic rhinosinusitis in the postoperative setting.