Systematic Review and Meta-analysis of the Change in Pharyngeal Bacterial Cultures After Pediatric Tonsillectomy

Objective To review all available biomedical literature to assess published data regarding the effect of pediatric tonsillectomy on the culture results of potentially pathogenic respiratory pharyngeal bacteria before and after surgery. Data Sources Biomedical literature databases (PubMed, Embase, Web of Science) from January 1970 to December 2019. Review Methods A systematic review of the literature was performed with the assistance of a medical librarian. Inclusion criteria consisted of pediatric patients and extractable data regarding respiratory bacteria culture data before and after tonsillectomy. Meta-analysis with random effects modeling was used on a limited basis. Results Only 5 studies met the inclusion criteria. The grand mean age was 5.9 years; the sample size range was 31 to 134; and the range of follow-up was 1 to 12 months. Group A beta hemolytic Streptococcus was generally the least commonly cultured pathogenic bacteria on preoperative cultures. Qualitative culture data generally showed an overall decrease in potentially pathogenic bacteria and some increase in nonpathologic respiratory flora after tonsillectomy. Meta-analysis showed significant reductions in postoperative culture rates for group A beta hemolytic Streptococcus (positive post- vs preoperative culture: risk ratio [RR], 0.144; 95% CI, 0-0.342), Haemophilus influenzae (RR, 0.437; 95% CI, 0.266-0.608), and Streptococcus pneumoniae (RR, 0.268; 95% CI, 0-0.567) and mixed results for Moraxella catarrhalis (0.736; 95% CI, 0.446-1.03) but no significant reduction for Staphylococcus aureus (RR, 0.774; 95% CI, 0.157-1.39). Conclusion The majority of published evidence shows that pediatric tonsillectomy appears to reduce the quantity of most cultured potentially pathogenic respiratory bacteria in the pharynx after surgery. The implications and possible benefits of this favorable change in the microbiologic environment after surgery require further study.