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

Abstract

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 3cm 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 30min; embolization time was 15min. Complete devascularization was achieved with no complications. Surgical resection was performed with lower than expected operative blood loss (150ml) and operative time (90min). 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.