Femoral artery will be cannulated with a 2.0 mm sheath of the embolization catheters and UAE will be performed by the same expert interventional radiologist with use of 355-500 μm polyvinyl alcohol particles (Boston Scientific and Cordis, Natick, MA, USA) suspended in 10 ml of iodixanol 270 mg I/ml (Visipaque; Nycomed Amersham, London, UK) mixed with 20 ml of isotonic saline. Embolization will be continued until cessation of UAE blood flow occurs.