CT features and risk factors of pulmonary cement embolism after vertebroplasty or kyphoplasty in patients with vertebral compression fracture: a retrospective cohort study

BACKGROUND: Pulmonary cement embolism (PCE) caused by cement leakage is one of the complications of percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP). The aim of our study was to explore the imaging features on computed tomography (CT) and analyze the risk factors of PCE in patients with a vertebral compression fracture to compare the incidences of PCE caused by PVP and PKP. METHODS: In this single-center, retrospective study, 373 patients (96 males and 277 females; mean age 76.2±9.4 years) from January 2017 to December 2020 who underwent PVP or PKP for treatment of vertebral compression fracture in the China-Japan Friendship Hospital were retrospectively included. Their clinical data were recorded, and their postprocedural chest CT scans were reviewed and evaluated for PCE. RESULTS: Of the 373 patients, 258 patients underwent PVP while the other 115 underwent PKP. PCE was found on the postprocedural chest CT scans in 64 patients (17.2%), including 47 patients with PVP and 17 patients with PKP. The incidence of PCE of PVP and PKP was similar (χ(2)=0.660; P=0.460). The typical CT findings of PCE were multiple linear or branching radiopaque densities in pulmonary arteries. The upper lobes of bilateral lungs were the most frequently involved. In addition, postprocedural chest CT demonstrated that 103 cases had cement emboli in the azygos vein, and 8 cases had cement emboli in the inferior vena cava. Binary logistic regression analysis demonstrated that PVP or PKP in the T9 vertebra [odds ratio (OR) =4.222; 95% CI: 1.490–11.966] and cement emboli in the azygos vein (OR =7.647; 95% CI: 3.937–14.856) or the inferior vena cava (OR =42.701; 95% CI: 7.525–242.302) were the risk factors of PCE. CONCLUSIONS: The incidence of PCE during PVP or PKP was 17.2%. Postprocedural chest CT clearly showed PCE as branching hyperdense or radiopaque lesions confined within the pulmonary artery courses. PVP or PKP in the T9 vertebra and cement emboli in the azygos vein or the inferior vena cava were risk factors for PCE.