Cement Leakage in Percutaneous Vertebroplasty for Spinal Metastases

Study Design. Retrospective assessment of risk factors using univariate and multivariate analyses. Objective. To evaluate risk factors retrospectively for cement leakage (CL), including vascular cement leakage (vCL) and cortical cement leakage (cCL), in percutaneous vertebroplasty of spinal metastasis. Summary of Background Data. Complications of vertebroplasty for spine metastasis are rare but related to extravertebral cement leakage that is pulmonary embolism and medullary compression. Better understanding of the risk factors for vascular and cortical types of cement leakage is necessary to prevent these complications. Methods. Fifty-six cancer patients (30 females, 26 males; age, 56 +/- 12 yr) (81 vertebrae) were treated in 58 sessions under fluoroscopy or computed tomography-fluoroscopy guidance. Leakage rates were reported. The following items were assessed for occurrence of CL, vCL, and cCL: primary tumor site, prior radiotherapy or local tumor ablation or embolization, appearance on computed tomography, cortical osteolytic destruction, vertebral collapse, operator's experience, guidance modality, and cement filling. Results. CL, vCL, and cCL rates were 53%, 25%, and 32%. History of prior treatment correlated with a decrease in CL (P = 0.018). vCL decreased when lung was the primary tumor site (P = 0.036), in osteolytic vertebrae (P = 0.033) or when there was a vertebral collapse (P = 0.037). cCL correlated with operator's experience (P = 0.021) and vertebral collapse (P < 0.001). Superior discal cCL correlated with superior endplate cortical destruction (P = 0.012). Although history of prior treatment seemed to be an independent protective factor (odds ratio = 0.24; 95% confidence interval, 0.087-0.7; P = 0.001), vertebral collapse was isolated as a risk factor for cCL (odds ratio = 32; 95% confidence interval, 6.7-161; P = 0.001). Conclusion. Risk factors for cCL and vCL are distinct. Vertebral collapse and cortical destruction are risk factors for cCL. History of prior treatment is a protective factor for CL.