Intra-Vertebral Contrast Phlebography During Balloon Kyphoplasty: A Cautionary Tale of Using Antegrade Inferior Vena Cavogram in Preventing Pulmonary Cement Embolism

Pulmonary embolism of cement is considered a catastrophic complication of kyphoplasty. Considering the predilection of thoracic and upper lumbar levels as well as the role of valveless vertebral plexus and abdominal caval system, we report the utility of performing an intra-osseous phlebography in the fractured vertebral body visualized through lateral view fluoroscopic cine-images to assess the direct contrast efflux towards the Inferior Vena Cava (IVC). The flow patterns of anterior external vertebral venous plexus and its tributaries are shown using schematic diagrams and fluoroscopic images. Stepwise technique of this perivertebral venogram is discussed as well as recognition of confounding paravertebral/ radiculomedullary arterial anatomy. The new venous channels opening up after balloon inflation are highly likely to be the surrogate pathways for cement embolization to the heart and pulmonary artery. This simple additional imaging step (“antegrade inferior vena cavogram”) helps to avoid anterior venous plexus extravasation of cement towards the IVC, using bipedicular contrast lavage and sequential injection using different viscosities. This article also highlights the management of pulmonary embolism using interventional radiology as well as open surgical methods. The article also eludes into some alternate vertebral augmentation device strategies to achieve complete obviation of cement extravasation as well.