Direct Tumor Embolization of Sinonasal Unclassified Spindle Cell Sarcoma

Introduction: Embolization is a well-established technique that facilitates the subsequent surgical removal of vascularized sinonasal tumors. Preoperative transarterial embolization (TAE) has proven beneficial for decreasing intraoperative blood loss and facilitating endoscopic visualization to aid in tumor removal. However, complete devascularization is often not achieved by TAE. Direct tumor embolization has been utilized to overcome this limitation. While this technique has been reported in the management of juvenile nasopharyngeal angiofibroma, other hypervascular tumors may also be managed using direct intratumoral embolization. We report our experience with direct tumor embolization of a highly vascular intranasal unclassified differentiated spindle cell sarcoma.

Method: A 45-year-old female presented to clinic with a large left nasal mass. Magnetic resonance imaging revealed multiple flow voids, and biopsy of this mass in the operating room led to extensive blood loss. Initial pathology was thought to be a hemangiopericytoma. In planning for endoscopic excision, the patient underwent bilateral internal maxillary artery endovascular embolization. However, extensive remaining blood supply on the superior aspect of the tumor via ophthalmic artery collaterals was noted on angiography. Direct tumor embolization with ONYX-18, an embolic system consisting of ethylene vinyl-alcohol copolymer (EVAC) in dimethyl-sulfoxide (DMSO) under endoscopic visualization was performed by directly puncturing the tumor with an 18 gauge spinal needle. Fluoroscopy was also utilized to ensure no embolic material spilled from the mass, and to ensure maximum diffusion into the mass.

Result: Good tumor penetration was achieved via direct tumor puncture without any embolic spill from the mass. Despite dual blood supply from both carotid systems, complete endoscopic tumor resection was achieved wih reasonable blood loss. Final pathology was consistent with intermediate grade unclassified spindle cell sarcoma. Follow up MRI 2 months post operatively showed no tumor recurrence.

Conclusion: Direct tumor embolization can be utilized in the resection of hypervascular sinonasal tumors, allowing for endoscopic visualization and complete tumor removal.