Intra-arterial Onyx Embolization of Vertebral Body Lesions
A 74-year-old male patient with ongoing persistent lower lumbar spine pain, shortness of breath, and cough was initially treated symptomatically for his pain and for presumed pneumonia. Computed tomography (CT) demonstrated an 11 mm right middle lobe lesion and an indeterminate 13 mm right adrenal lesion, prompting further evaluation with positron emission tomography (PET)-CT. A PET-CT demonstrated a fluorodeoxyglucose (FDG)-avid left renal mass suggestive of malignancy with an associated L2 vertebral body and left humeral head destructive lesion. He underwent total spine magnetic resonance imaging (MRI) and lumbar spine CT imaging, revealing a large destructive L2 vertebral body lesion with a pathologic fracture and 4-mm soft tissue extension into the ventral spinal canal, resulting in moderate left-sided spinal canal narrowing (). Significant L2-L3 left subarticular zone, neural foraminal narrowing, and compression on the left traversing L3 and exiting L2 nerve roots were also identified. There was no cord compression or signal abnormality. The patient was referred for embolization prior to planned surgical resection.\nThe patient was placed under general anesthesia and standard access with a 5 French sheath in the common femoral artery was achieved. A 5 French Mickelson catheter (Cook Medical Inc., Bloomington, IN, USA) was employed to selectively catheterize the left L2 segmental artery and an angiographic run demonstrated an obvious pathologic blush in the region of the L2 vertebral body (). Opacification of a spinal pial artery (artery of Adamkiewicz) was not seen. An Echelon microcatheter (eV3, Plymouth, MN, USA) was advanced through the Mickelson catheter (Cook Medical Inc., Bloomington, IN, USA) into the distal left L2 segmental artery and Onyx-18 (eV3, Plymouth, MN, USA) was injected, creating a cast within the segmental artery. The injected Onyx-18 was allowed to reflux into the vertebral body until the metastatic lesion was completely embolized (). A total volume of 0.64 milliliters (mL) of Onyx was used. Subsequent selective injection of the right L2 segmental artery demonstrated minimal pathologic blush. The total fluoroscopy time for the procedure was 33 minutes, and the procedural duration was 2.5 hours. Post-procedure plain X-ray films confirmed Onyx distribution in the left half of the vertebral body, within the tumor (). The patient subsequently underwent an uneventful corpectomy and fusion with minimal blood loss (less than 100 cc) and recovered without complications.