Pre-operative embolization of hypervascular spinal metastasis using percutaneous direct intra-tumoural injection with Onyx under local anesthesia

Intra-operative blood loss remains a major cause of perioperative morbidity for patients with hypervascular spinal metastasis undergoing surgery. Pre-operative embolization is used to reduce intraoperative blood loss and operative time. This is commonly performed under general anesthesia via a trans-arterial approach, which carries a risk of spinal stroke. We propose an alternative technique for embolization of hypervascular metastases using the Onyx embolic agent via a percutaneous direct intra-tumoural injection under local anesthesia and sedation to reduce embolization risks and procedure time, as well as operative blood loss and operative time. A 74-year-old man presented with thoracic myelopathy with back and radicular pain on background of metastatic renal cell carcinoma. Magnetic resonance imaging (MRI) revealed a 3. cm mass centered on the right lamina of T10 with extension into the spinal canal. The patient underwent a percutaneous imaging-guided direct intra-tumoural contrast parenchymogram, and Onyx embolization via a single needle. Initial needle placement and tumour assessment was completed in 30. min; embolization time was 15. min. Complete devascularization was achieved with no complications. Surgical resection was performed with lower than expected operative blood loss (150. ml) and operative time (90. min). His pre-operative symptoms improved, and he was discharged home the following day. At 6-month follow-up there was no recurrence of his symptoms. Further evaluation of direct percutaneous intra-tumoural Onyx embolization for hypervascular spinal tumours is warranted.