Mechanical Embolectomy of a Large Iliocaval Fat Embolus

Fat embolism syndrome (FES) is a rare, yet serious, condition associated with trauma and orthopedic surgeries. The pathogenesis is thought to be increased intramedullary pressure leading to adipose tissue extrusion into venous structures, causing systemic embolism. In the past decade, significant technological advancements have been made with devices capable of mechanical and aspirational embolectomy. This paper presents the management of a large iliocaval fat embolus in an 87-year-old female using the Inari (Inari Medical) Protrieve, FlowTriever, and RevCore. The patient was an 87-year-old female with a previous medical history significant for hyperlipidemia, hypertension, and had undergone hip surgery 2 weeks prior. She presented to our emergency department with abdominal pain and bloody stools. CT scan revealed a hypoattenuating filling defect in the distal inferior vena cava (IVC) and iliac veins (Fig 1). A fat embolus was suspected, and an urgent embolectomy was performed. The patient was positioned supine, and her right internal jugular vein was accessed. A Protrieve Sheath was used with its mesh funnel deployed in the IVC. A venogram confirmed the large embolus. Mechanical embolectomy involved the use of the Inari FlowTriever, and RevCore devices, guided by intravascular ultrasound (IVUS) for lesion characterization. The Flowtriever's mesh disks were found to be too compliant to impact the lesion, whereas the RevCore was able to successfully mobilize the embolus into the Protrieve mesh funnel and was subsequently aspirated (Fig 2). IVUS confirmed successful extraction. Postoperative imaging demonstrated a patent IVC and iliac system. Histopathology of the aspirated embolus confirmed a fat embolus with organized changes. The patient's recovery was unremarkable, and follow-up at 1 month revealed a patent IVC with no residual filling defects. This case underscores the successful application of contemporary thrombectomy techniques for managing a rare, organized fat embolus. The Inari ProTrieve sheath, combined with the RevCore, demonstrated efficacy in embolus extraction. Notably, IVUS provided valuable insights into the embolus morphology and aided in its visualization during extraction. The findings suggest that modern mechanical thrombectomy technologies, coupled with IVUS, can be effective in treating fat emboli. This experience contributes to the evolving landscape of endovascular interventions for fat embolism syndrome, emphasizing the importance of early consideration of these techniques in similar cases.Fig 2Large, organized fat embolus aspirated from the Inari Protrieve sheath.View Large Image Figure ViewerDownload Hi-res image Download (PPT)