Safety and efficacy of vascular tumor embolization using Onyx: Is angiographic devascularization sufficient? Clinical article

Object. The authors assessed the safety and efficacy of embolization of head, neck, and spinal tumors with Onyx and determined the correlation between tumor embolization and intraoperative blood loss. Methods. The authors prospectively collected all head, neck, and spinal tumors embolized with Onyx at their institution over a 28-month period. Information on tumor type, location, extent of tumor devascularization, endovascular and surgical complications, and intraoperative estimated blood loss (EBL) was evaluated. Results. Forty-three patients with various head, neck, and spinal lesions underwent vascular tumor embolization with Onyx. Indications for embolization included uncontrolled tumor bleeding in 8 cases, elective preoperative devascularization in 34, and tumor-induced consumptive thrombocytopenia in 1 case. Embolization was performed via direct tumoral puncture in 14 cases and through the traditional transarterial route in the remaining lesions. Embolization was successful in ending uncontrolled tumor bleeding in all 8 cases and in reversing the consumptive coagulopathy in 1 case. Intraparenchymal penetration of embolic material was possible in all percutaneously embolized tumors and in 4 of the 20 tumors embolized preoperatively via the transarterial route. The mean percentage of devascularization in tumors with intraparenchymal penetration of Onyx was 90.3% compared with 83.7% in tumors without intraparenchymal penetration. The mean EBL with intraparenchymal penetration of Onyx was significantly lower than when there was no intraparenchymal penetration (459 vs 2698 ml; p = 0.0067). There were no neurological complications related to the embolization procedures. Conclusions. Embolization of vascular tumors with Onyx can be performed safely but may not reach optimal effectiveness in reducing intraoperative EBL if the embolic material does not penetrate the tumor vasculature. In the authors' experience, the best method of intraparenchymal penetration is achieved with direct tumor puncture. Transarterial embolization may not result in tumor penetration, particularly when injected from a long distance through small caliber or slow flow vessels.