Features of Hepatic Abscesses on Computed Tomography: Predicting the Outcomes of Percutaneous Catheter Drainage or Needle Aspiration

Background: Percutaneous catheter drainage (PCD) and percutaneous needle aspiration (PNA) have become the primary options for treating hepatic abscesses. Thus far, various studies have examined the clinical data and computed tomography (CT) features for predicting PCD outcomes. Objectives: The goal was to compare CT features between hepatic abscesses classified based on strain and quantitative outcome of PCD or PNA, and to analyze clinical outcomes. Patients and Methods: Eighty-seven patients who had undergone PCD or PNA with pyogenic hepatic abscess in a 5-year period were included. They were divided into Klebsiella pneumoniae monomicrobial pyogenic hepatic abscess (KHA) group and non- Klebsiella pneumoniae monomicrobial or polymicrobial pyogenic hepatic abscess (non-KHA) group. Patients were categorized into the following subgroups based on strain and percentage of initial drainage volume per CT volume: groups A (< 50%) and B (≥ 50%), groups C and D in KHA group, and groups E and F in non-KHA group. We compared clinical findings, CT features, and clinical outcomes between the two groups, respectively. Results: In univariate and multivariate analysis, patients with KHA group were associated with less frequent rim enhancement (P = 0.024). More frequent occurrence of thicker wall (P < 0.001) and lower mean attenuation (P = 0.047) were the most significant predictors in group B and thicker wall (P = 0.002) was the most significant predictor in group D. Length of hospitalization in group D was significantly shorter than that in group C (P = 0.026). Conclusion: Less frequent occurrence of rim enhancement on CT may serve as an indicator of KHA and presence of thick wall on CT may serve as a predictor of greater percentage of initial drainage amount per CT volume during PCD or PNA in hepatic abscess with a tendency of shorter length of hospital stay. Hence, CT findings may be useful for predicting the outcome of PCD or PNA in patients with hepatic abscess.