Cement vertebral augmentation has a role in neoplastic lytic lesions of the spine for pain palliation and structural strengthening. In fact, differently from osteoporotic compression fractures, neoplastic vertebral fractures have a high potential of compression and compromise of neural structures. The more extensive the lytic involvement of the vertebral body, the higher the risk of fracture, and consequently, in theory, the more desirable a structural strengthening with bone cement.

Unfortunately, in such cases the indication for the treatment has to be balanced with its risks. While vertebral augmentation in osteoporotic fractures is known to have a very good safety profile, the literature reports a significantly higher complication rate in neoplastic cases. Possible reasons for such complications, besides the inherent fragility of neoplastic patients, rest in the combination of tumoral tissue in the vertebral body (in some cases highly vascularized) competing or unpredictably influencing the distribution of the injected bone cement and the discontinuity of eroded cortical bone facilitating fluid cement leakage outside of the vertebral body boundaries. In particular, cortical erosion of the posterior wall represents a relative contraindication to vertebral augmentation due to the increased risk of cement leak in the epidural space, with potential compression of nervous structures. Similarly,

the frequent association with an epidural soft tissue mass reduces the security space in the central canal, and poses the risk for cement injection to further displace soft tissue in the central canal. Nevertheless, these conditions are not rare, and may represent those critical cases that most need vertebral augmentation.

Our aim was to assess vertebral augmentation in vertebrae with posterior wall erosion and epidural mass. We evaluated the technical success of filling the vertebral body with cement, in order to ensure mechanical support and stability, technical complications such as epidural cement leak, and their clinical relevance, along with other clinical complications. In our consecutive series we observed that epidural cement leaks do occur but are usually small and rarely symptomatic. In fact, we reported a clinically significant complication in only 1.5% of cases. The technical success rate was also very satisfactory.

These are certainly challenging cases, and results may be operator-dependent. The procedures were individualized rather than standardized, yet we thought that some technical factors positively influenced the overall low complication rate and good technical success results. We stressed the importance of image-guidance quality, with correct visualization at the target level; when deemed appropriate, intra-operative myelography and/or CT-guidance were used; cavity creation in the vertebral body was obtained in most cases with plasma ionization (coblation), osteotomic curette, or inflatable balloons. Finally, real-time fluoroscopic visualization during injection of high-viscosity PMMA bone cement was adopted so that cement leaks could be recognized early and limited.

These results show that we can offer with a reasonable safety profile a valid minimally invasive option for pain palliation and stabilization to patients with critical and challenging lytic vertebral body lesions. Yet these procedures remain challenging and deserve respect from the operator, because significant complications may occur.

 

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