Multimodal ultrasound in the diagnosis and treatment of caudate lobe Klebsiella pneumoniae liver abscess complicated by rare gas-containing inferior vena cava thrombosis: a case report

BACKGROUND: Klebsiella pneumoniae liver abscess (KLA) is an emerging public health concern in Asia. Involvement of the caudate lobe with concurrent inferior vena cava thrombosis is exceedingly rare but life-threatening. Timely diagnosis and management are critical but challenging. Multimodal ultrasound can play a pivotal role in both diagnosis and treatment guidance. CASE PRESENTATION: A 66-year-old woman with diabetes presented with 10 days of fever and chills. Imaging revealed a caudate lobe liver abscess containing gas with extension to the inferior vena cava (IVC) and associated septic thrombosis. Contrast-enhanced ultrasound and CT confirmed a Klebsiella pneumoniae liver abscess. Ultrasound-guided percutaneous drainage was performed, and cultures identified an ESBL-producing Klebsiella pneumoniae. The patient was treated with broad-spectrum antibiotics, therapeutic anticoagulation, and catheter drainage. Despite an episode of septic shock during hospitalization, she gradually improved, and follow-up imaging showed near-complete resolution of the abscess and complete disappearance of the IVC thrombus. CONCLUSION: The caudate lobe KLA complicated by IVC thrombosis, particularly gas-containing septic thrombosis, is rare but life-threatening. Multimodal ultrasound plays an important role in the early diagnosis and interventional management of KLA complicated by IVC thrombosis. Timely ultrasound-guided drainage with targeted antimicrobial therapy and individualized anticoagulation can achieve effective source control and favorable outcomes without open surgery.