Management of Pyogenic Liver Abscesses

Pyogenic liver abscesses (PLAs) are a suppurative infection of the hepatic parenchyma responsible for significant morbidity and mortality. PLAs are categorized into a variety of mechanisms: (1) via the portal vein, (2) through the biliary tract, (3) via the hepatic artery, (4) from trauma, (5) contiguously via direct extension, and (6) cryptogenically. The pathogenesis of PLA, which informs treatment, can often be discerned based on host factors, clinical presentation, and causative microorganisms. The Streptococcus anginosus group, hypervirulent Klebsiella pneumoniae , and multidrug-resistant gram-negative pathogens have emerged as microbiologically challenging organisms to treat. The identification of hypervirulent K. pneumoniae should prompt for assessment for metastatic spread and consideration of prolonged antimicrobial treatment. Abdominal imaging is indispensable in characterizing PLAs and facilitating source control interventions. Source control remains the most critical aspect of PLA management, followed by antimicrobial therapy. Empiric antibiotics for PLAs are informed by the suspected etiology of PLA formation. Duration of antimicrobial therapy is individualized and dependent on multiple components, including the success of achieving source control, host factors, mechanism of PLA development, and the illness course of the individual—factoring in clinical, biochemical, and radiographic parameters.