Pulmonary thromboembolism caused by bone cement emboli
Radiologic Findings
Chest PA shows tiny calcific foci in right hilar area. High densiy is noted in thoracic vertebrae due to previous vertebroplasty. Contrast enhanced CT images show intraluminal thrombus mixed with high attenuating foci in pulmonary trunk and both main and interlobar pulmonary arteries.
Noncontrast CT images(below) show hairpin appearance of high attenuated linear opacties in azygos vein, superior vena vava, right atrium, and right ventricle, and pulmonary arteries.
Brief Review
Pulmonary thromboembolism caused by bone cement emboli after percutaneous vertebroplaty
1. Mostly caused by polymethylmethacrylate (PMMA)
- still too liquid or by applying too much pressure while injection
2.Pathophysiology
A.Percutaneous vertebroplasty (PV) is an interventional radiologic procedure that involves injection of acrylic bone cement into a diseased vertebral body under fluoroscopic or CT guidance.
B.The method was first described by Galibert in 1987 and has since become a standard treatment for osteoporotic vertebral compression fractures and osteolytic vertebral tumours.
C.Because the cement is injected into the vertebral body under high pressure there is a high risk of it entering the perivertebral venous plexus (segmental vein), vena cava and eventually into the pulmonary arteries.
D.It may also induce a local inflammatory reaction at the vessel wall, leading to superimposed thrombosis on the surface of the cement and propagation of a thrombus down into the pulmonary tree.
References
1. Kaufmann TJ et al. A technique to circumvent subcutaneous cement tracts during percutaneous vertebroplasty. AJNR 2004;25:1595-1596