Outcome of medical treatment of bacterial abscesses without therapeutic drainage: Review of cases reported in the literature

The usual treatment of bacterial abscesses, except lung or tube-ovarian abscesses, includes therapeutic drainage. Increasing evidence suggests that some abscesses respond to antimicrobial therapy without drainage. To study this issue, a MEDLINE search of the literature (1966-1994) was performed for cases of bacterial abscess in which treatment without definitive drainage was attempted. Four hundred sixty-five cases were identified. The most commonly involved organs were the liver, brain, and kidney. The success rate of antimicrobial therapy was 85.9%. Factors that predicted a less favorable outcome were abscess diameter of greater than or equal to 5 cm (odds ratio [OR] = 37.7; P = .0003), involvement of greater than or equal to 1 organism (OR = 5.2; P = .014), presence of gram-negative bacilli COR = 3.4; P = .022), length of therapy of < 4 weeks (OR = 49.1; P < .0001), and use of an aminoglycoside as the only active agent (OR = 11.8; P = .008). Many bacterial abscesses can be treated without drainage; abscess size, the organisms involved, and therapy utilized may influence outcome.