What is the definition of polymethylmethacrylate (PMMA) pulmonary cement embolism?
PMMA Pulmonary embolism refers to the embolization of acrylic cement into the lungs. PMMA is used in vertebroplasty and kyphoplasty to treat vertebral compression fractures secondary to osteoporosis or malignancy. Pulmonary cement embolism occurs due to the extravasation of the cement from the vertebral body into the adjacent vasculature. Multiple myeloma has the highest risk of pulmonary cement embolism.
Which are the clinical manifestations of pulmonary PMMA cement embolism?
Most patients with pulmonary PMMA embolism are asymptomatic or present mild pulmonary symptoms, and it may be detected incidentally for imaging done for another reason. However, some rare patients may exhibit severe symptoms, even life-threatening.
What are the radiographic and computed tomography (CT) features of pulmonary PMMA embolism?
Pulmonary PMMA embolism may show multiple dense opacities with a tubular branching shape scattered throughout the lungs, corresponding to segmental and subsegmental pulmonary arteries distribution, without reactive pulmonary changes. CT may show extruded cement within the cardiac chambers and paravertebral and epidural veins.
What consists of the general treatment of pulmonary PMMA embolism?
There is not enough evidence-based data to underlay the treatment strategy. The therapeutic of pulmonary PMMA embolism includes observation and follow-up in asymptomatic patients with peripheral embolism. In some symptomatic patients or with central cement embolism, Despite controversies, the treatment may be initial administration of heparin or coumarin treatment for 3-6 months. Embolectomy only in rare severe cases of central cement embolism.
What are the complications of extravasation of PMMA due to vertebroplasty and kyphoplasty?
The complications of extravasation of PMMA in vertebroplasty and kyphoplasty are spinal cord compression, nerve injury, intervertebral disc involvement, cardiac embolization, and perforation from cement material lodged in cardiac chambers, and pulmonary embolism of PMMA due to leakage of cement into perivertebral veins.
The CT images show multiple small tubular branching high dense opacities distributed in the segmental and subsegmental branches of pulmonary arteries bilaterally, predominantly on the right side, representing pulmonary acrylic cement embolism - polymethylmethacrylate (PMMA). There is also a PMMA fragment in the right ventricle. There is not lung infarction, nor pleural effusion.
There are widespread osseous changes of multiple myeloma, characterized by osteopenic bone, lytic lesions, and various vertebrae endplate fractures, resulting in kyphosis. CT features of status post vertebroplasty with cement in treated vertebral bodies T12, L1, and L2. The dense lines beyond the confines of these vertebral bodies correspond to leakage of PMMA into the perivertebral veins.
Impression: The CT features are consistent with post-vertebroplasty pulmonary cement embolism.