['To evaluate the efficacy and safety of gelified ethanol, a newly developed sclerosing agent for slow-flow vascular malformations.', 'Seventy-nine sclerotherapy procedures were performed on 44 patients with 37 venous malformations, 2 glomuvenous malformations, 2 lymphatic malformations, 2 lymphatico-venous malformations, and 1 Klippel-Trenaunay syndrome. The median injected volume was 1.00 mL/site of injection. Effects of sclerotherapy on pain, functional and cosmetic disturbance were statistically evaluated with a final result score. Local and systemic complications were recorded.', 'The mean Visual Analogue Scores were 5.20 \u2009±\u2009 2.81 before and 1.52\u2009 ±\u2009 1.25 after treatment (p\u2009<\u20090.001). Functional and aesthetic improvement was achieved in 31/35 patients (89%) and in 33/41 (80%), respectively. Minor local side effects included necrosis with or without issue of ethylcellulose, palpable residue, and hematoma. No systemic side-effects occurred.'] Is radio-opaque ethylcellulose-ethanol a safe and efficient sclerosing agent for venous malformations?