Feasibility of using hyperosmolar mannitol as a liquid tumor embolization agent.

BACKGROUND AND PURPOSE This study assesses the cytotoxicity of hyperosmolar mannitol on human endothelial and meningioma cells in vitro and summarizes the initial clinical experience of using mannitol as a liquid tumor embolization agent. METHODS Human umbilical vein endothelial cells and primary meningioma cells from surgical specimens were treated with 300, 600, 900, and 1200 mOsm of mannitol, mannitol and iohexol mixture, saline, and iohexol alone. Cell death was evaluated with a Live/Dead kit and quantified with thymidine incorporation. From 1998 to 2004, 23 patients with meningioma were treated with mannitol and 31 patients were treated with polyvinyl alcohol (PVA) particles alone. Angiographic results, procedural complications, intraoperative observation, and estimated blood loss during surgical resection were retrospectively evaluated. RESULTS Minimal endothelial cell death was seen after incubation with 300 mOsm of mannitol for 15 minutes, but 43 +/- 2% of endothelial cells were damaged by 1200 mOsm of mannitol after 30 minutes. Five meningioma cell lines exhibited significant cell death (22 +/- 2%; P < .05) after incubation with mannitol. Satisfactory angiographic results were obtained in all 23 patients. Tumor necrosis was observed intraoperatively and confirmed pathologically. There was no significant difference in estimated blood loss between mannitol- and PVA-embolized patients (407 +/- 64 mL vs 381 +/- 50 mL; P > .75). CONCLUSION High concentration of mannitol can injure endothelial cells and meningioma cells in a short period of time. It is feasible to use mannitol as a liquid embolic agent to treat meningioma.