Background: Percutaneous catheter drainage (PCD) is currently the preferred therapeutic procedure of pyogenic liver abscesses (PLAs). However, multilocular poorly liquefied PLAs (MPLPs) are unsuitable for PCD. As reports on MPLPs are scarce, we aimed to explore possible therapeutic strategies for this serious type of PLA.

Methods: The medical records of patients with PLA who were hospitalized at our institution between January 2011 to December 2015 were retrospectively reviewed. Demographic factors, biochemical, bacteriological, and imaging results, and treatment outcomes were evaluated.

Results: Fourteen patients with MPLPs and 37 with drainable PLAs were identified and included in the study. Clinical characteristics were generally similar between the two groups. Klebsiella pneumoniae accounted for the majority of the culprit pathogens in MPLPs. Patients with MPLPs were managed medically without PCD. Despite this, treatment outcomes were not inferior compared to patients with drainable PLAs. Contrast-enhanced images revealed that the intricate septa of the MPLP maintained its blood perfusion. Most MPLPs did not liquefy over the treatment period.

Conclusion: We should remember that MPLP is not rare. The septa may have delivered antibiotics adequately into the MPLPs, thus producing good treatment outcomes. Despite our findings, a high level of suspicion of treatment failure is crucial in these patients to ensure favorable treatment outcomes.

Keywords: pyogenic liver abscess, multilocular, liquefaction, drainage, klebsiella pneumonia

ESBL, extended-spectrum β-lactamase; PCD, percutaneous catheter drainage; PLA, pyogenic liver abscess; MPLP, multilocular poorly liquefied pla

Pyogenic liver abscess (PLA) is the most frequent, potentially life-threatening type of visceral abscess, with an increasing incidence worldwide.^1,2 The etiologies and microbiological spectrum show distinct regional differences around the world. Klebsiella pneumoniae is the most common causative pathogen of PLA in eastern Asian countries,^3–5 whereas Streptococcus spp. predominates in Europe, Canada, and Australia.^6–10 However, recently, Klebsiella pneumoniae has become a more frequent causative pathogen of PLA in Western countries.^11,12

Although there is no consensus on the guidelines regarding optimal management strategies of PLA, percutaneous catheter drainage (PCD) is currently the initial treatment option of choice.^13,14 In the majority of patients, PCD is reported to be a safe and sufficient treatment, even for huge PLAs measuring ≥10cm.¹⁵ In this modern era of minimally invasive PLA management, multilocular poorly liquefied PLA (MPLP) remains a challenge. MPLP is unsuitable for PCD due to its intricate septations and thick viscid pus, and therefore it is treated rather reluctantly with antibiotics alone. This conservative treatment strategy sometimes raises concerns about the risk of treatment failure and certain complications. Indeed, we have experienced a case of huge MPLP with an intraperitoneal rupture who required surgical treatment.¹⁶ This MPLP was caused by Klebsiella pneumoniae infection, which is reported to be often associated with multilocular PLA.^17,18

Diagnosis of multiloculation of PLA may vary depending on the capacity of the imaging modalitie