Frequency and Outcome of Pulmonary Polymethylmethacrylate Embolism during Percutaneous Vertebroplasty

BACKGROUND AND PURPOSE: During percutaneous polymethylmethacrylate (PMMA) vertebroplasty (PV), PMMA cement may migrate into the venous system and subsequently be transported to the pulmonary arteries. Frequency, outcome, and imaging findings of PMMA pulmonary embolism are poorly understood. We retrospectively assessed the frequency and outcome of PMMA embolism during PV in a large patient cohort and evaluated the relationship of the volume of injected PMMA to the occurrence of pulmonary PMMA embolism. MATERIALS AND METHODS: Between 2001 and 2007, 532 osteoporotic compression fractures in 299 consecutive patients were treated with PV. PMMA embolism was defined as venous PMMA migration toward the lungs visible on biplane fluoroscopy during PV. CT was performed immediately and 1 year after PMMA migration. RESULTS: Venous PMMA migration occurred during 11 PVs in 11 patients (2.1%, 95% confidence interval, 1.1–3.7%). CT in 8 patients demonstrated small peripheral pulmonary PMMA emboli. All 11 patients remained asymptomatic during 1-year follow-up. Repeat CT scanning after 1 year in 6 patients demonstrated unchanged pulmonary PMMA deposits without late reactive changes. Mean injected cement volume in patients with and without PMMA embolism was not different (3.6 ± 1.06 mL versus 3.3 ± 1.16 mL, P = .43). Similar comparison for thoracic and thoracolumbar vertebrae yielded P values of .07 and .9. CONCLUSION: Pulmonary PMMA embolism during PV is an infrequent complication without permanent clinical sequelae. After 1 year, no pulmonary reaction was seen on CT. No definite relationship of PMMA emboli with injected cement volume could be established.