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.