Gas-forming pyogenic liver abscess: A world review

Backgrounds/Aims Gas-forming pyogenic liver abscess (GFPLA) has an incidence of up to 30% of all pyogenic liver abscesses (PLA). GFPLA has higher mortality compared to non-GFPLA. Mere presence of gas within abscess may not determine clinical outcome. Hence it is important to study biologic characteristics that make GFPLA a distinct clinical entity. The aim of this study was to conduct a world review on GFPLA. Methods We conducted literature searches in PubMed using the following MeSH terms: "gas forming" AND "Liver abscess, pyogenic", "gas" AND "Liver abscess, pyogenic", "gas" AND "Liver abscess", "gas forming" AND "Liver abscess". Thirteen case series including 313 GFPLA patients were included. Age, gender, diabetes mellitus (DM), bacteriology, underlying etiology, symptoms, investigations, operative indications, and mortality rates were tabulated. Results GFPLA is often cryptogenic. There was no difference in age, gender, or symptomatology between GFPLA and non-GFPLA patients. DM was more common in patients with GFPLA compared to that in non-GFPLA patients (mean: 83.5% vs. 38.3%). Klebsiella pneumoniae is the most common causative pathogen. GFPLA has higher mortality compared to non-GFPLA (mean: 30.3% vs. 9%). Conclusions GFPLA is associated with DM and monomicrobial Klebsiella pneumoniae infection. GFPLA has high mortality. It needs to be recognized as a distinct clinical entity.