Histologic investigation of vascular malformations of the face after transarterial embolization with ethibloc and other agents. Twenty-one vascular malformations located in the facial area, 11 high-flow arteriovenous malformations and 10 slow-flow malformations, underwent combined treatment by embolization and later surgery. Embolization was performed simultaneously with superselective angiography of the branches of the external carotid artery. The new biodegradable fibrosing agent Ethibloc was used in 16 cases. Histologic examination of the surgical specimens confirmed the good target orientation by the transarterial injection of Ethibloc. Limitations of this technique are discussed. The agent proved to have thrombogenic and fibrogenic properties. Some of the vascular walls degenerated and ruptured following the embolization, but there were no instances of necrosis of interstitial tissue or skin. Embolization treatment of vascular malformations of the face was not curative, but it facilitated subsequent surgery in all examined cases. 