Teaching Case

A 63-year-old woman visited the emergency department because of one-week-lasting worsening dyspnoea with associated chest pain. ECG showed atrial fibrillation with tachycardic ventricular response without any sign of myocardial ischemia. Patient had a history of arterial hypertension. There was no history of previous endovascular procedures. History of thoracolumbar osteosynthesis and vertebroplasty of vertebrae Th12-L2 was obtained only retrospectively.

Orientational point-of-care cardiac ultrasound was performed which showed signs of cardiac failure. Furthermore, a linear hyper-echoic structure with associated posterior acoustic shadow in the vena cava inferior was noted that could not be explained.

Chest radiograph showed changes associated with cardiac failure – enlarged heart silhouette, interstitial oedema and bilateral pleural effusions. 

Additionally, CT pulmonary angiogram (CTPA) was performed and pulmonary embolism was excluded. CTPA also showed changes associated with heart failure – enlarged heart chambers, small bilateral pleural effusions, ground-glass opacities in the dependent parts of lung, thickened septal lines and reflux of contrast medium into vena cava inferior and hepatic veins. Osteosynthetic material following transpedicular thoracolumbar vertebrae fixation and cement material in the vertebral bodies of Th12 – L2 after vertebroplasty were evident. Additionally, a partly shown highly radiopaque thin linear foreign body in the lumen of infra-hepatic part of vena cava inferior was described.

Retrospective analysis of previous radiographs of the lumbar spine showed the radiodense linear formation in the projection of vena cava inferior extending distally to vertebral bodies of Th12 – L2 where firmly distributed cement was seen. Exactly same linear formation could also be observed on images that were performed during the vertebroplasty procedure and furthermore radiographs prior to the procedure showed no radiodense foreign formations.

Percutaneous vertebroplasty (PVP) is a safe, minimally invasive, efficient treatment for vertebral compression fractures. [1,2] The procedure is performed by percutaneous injection of polymethyl methacrylate (PMMA) into the fractured vertebral corpus [2] and offers superior results to conservative treatment. [1] The procedure was performed in our case because the patient had suffered an osteoporotic fracture of vertebra L1.

Cement leakage is the most frequently reported complication of PVP occurring in up to 73% cases and is mostly asymptomatic. [3] Severe complications which include pedicle fracture, pulmonary embolism, cement leakage into a major vein or spinal canal, pneumothorax or spinal cord compression have been reported in less than 1 %. [1,2]

Cement leakage may occur through a cortical defect into the disc space or paraspinal soft tissues, via the paravertebral veins, through the basivertebral foramen or via the needle channel [1,2,4]. In our case, the PMMA leaked outside of the left anterior cortical fracture site of the L1 vertebral body and migrated via the anterior external vertebral venous plexus into the inferior vena cava.

Cement leakage may be detected during or after the procedure. Since most cases are asymptomatic, it is usually an accidental finding detected by ultrasonography, radiography, or computed tomography. [1] Ultrasonographic appearance of the cement leakage is of a hyper-echoic focus with associated posterior acoustic shadow. Additional findings may include decreased velocity of blood flow in inferior vena cava, inability to compress the vessel and monophasic waveform in the Doppler mode. [1] In the case of intravasated cement an irregular radiodense linear focus in the topography of the inferior vena cava or anterior external vertebral venous plexus may be observed on the frontal and lateral thoracolumbar spine radiographs. [1] In case of suspected intravasated cement non-contrast CT is the study of choice where finding of irregular high density focus within the hypo-dense inferior vena cava may be detected. [1,4] MRI due to its intrinsic lack of T1WI/T2WI signal of the cement is not useful in this setting. [1]

Asymptomatic patients with a minor cement leakage require no intervention, while in cases of symptomatic thrombotic venous or pulmonary emboli or other serious complications anti-coagulation or even surgical treatment should be considered. [1] Some articles recommend preventive anti-coagulation therapy, insertion of a vena cava filter in asymptomatic patients with early imaging showing cement leakage and embolization after percutaneous vertebroplasty. [1,2,3]

Teaching point: Cement leakage into the venous system, including major vessels, notably inferior vena cava, may appear as an accidental finding on ultrasonography, radiography or CT of thorax and abdomen. Early treatment with anti-coagulation therapy or precautionary vena cava filter insertion may also be helpful even for asymptomatic patients in prevention of embolism or other complications.

Written informed patient consent for publication has been obtained.