Background and purpose: The reported incidence of PCE during PV varies, depending on the sensitivity of diagnostic tests used. To assess the true incidence of PCE, we performed native chest CT during follow-up in a large proportion of patients from the VERTOS II trial.
Materials and methods: VERTOS II is a prospective multicenter randomized controlled trial comparing PV with conservative therapy in 202 patients. After a mean follow-up of 22 months (median, 21 months; range, 6-42 months), 54 of 78 patients (69%) with 80 vertebrae treated with PV underwent native chest CT to detect possible PCE. The presence, location, number, and size of PCE were recorded. In addition, the presence of pulmonary parenchymal changes adjacent to PCE was noted. Possible risk factors for PCE, such as age, sex, number of treated vertebrae, cement volume per vertebra, and presence and location of perivertebral cement leakage, were evaluated.
Results: PCE was detected in 14 of 54 patients (26% 95% CI, 16%-39%). All patients were asymptomatic. Cement emboli were small and randomly distributed in peripheral small vessels. There were no reactive pulmonary changes. Cement leakage in the azygos vein was the only risk factor for the occurrence of PCE (OR, 43; 95% CI, 5-396).
Conclusions: Small and clinically silent PCE occurred in a quarter of patients treated with PV. Cement leakage into the azygos vein was the only risk factor. With time, these small cement emboli remained inert, without inflammatory pulmonary response. Standard postprocedural CT or chest radiographs are not necessary.
Trial registration: ClinicalTrials.gov NCT00232466.