A Retrospective Study of Pyogenic Liver Abscess Caused Primarily by Klebsiella Pneumoniae Vs. Non-Klebsiella Pneumoniae: CT and Clinical Differentiation

Purpose: The incidence of Klebsiella pneumoniae pyogenic liver abscesses (KP-PLA) is increasing. However, its diagnosis and treatment are often delayed, leading to complications. In this study, we aimed to retrospectively compare computed tomographic (CT) features of KP-PLAs with those of abscesses caused by other bacterial pathogens (non-KP-PLAS) and to further identify prognostic factors for PLA.

Methods: Data of 219 study patients including clinical presentation, comorbid conditions, metastatic infection, treatment duration, and mortality were retrospectively collated. CT characteristics of abscesses were recorded. Etiology was established by pus and/or blood culture. The differentiating CT features and clinical findings were compared between the monomicrobial KP-PLA and non-KP-PLA groups. Furthermore, factors related to in-hospital case fatality were analyzed.

Results: Multivariate analysis identified thin-walled abscesses, absent rim enhancement, metastatic infection, and absence of underlying biliary tract disease as significant predictors of KP-PLA. With 3/4 criteria applied in combination, a specificity of 96.5% was achieved for KP-PLA diagnosis. The in-hospital mortality rate was 3.7%. Multivariate analysis revealed that diabetes mellitus (P = 0.031), multiple abscesses (P = 0.026), internal gas bubble (P = 0.041), metastatic infection (P = 0.004), and septic shock (P = 0.002) were significantly associated with mortality.

Conclusion: Thin-walled abscess, metastatic infection, absence of rim enhancement, and absence of underlying biliary tract disease are potentially useful CT findings for early KP-PLA diagnosis.