Embolization of peripheral arteriovenous malformations and fistulas with precipitating hydrophobic injectable liquid (PHIL

This paper reports on the preliminary experience of a single center in the embolization of peripheral AVMs and fistulas with precipitating hydrophobic injectable liquid (PHIL®), focusing on technical aspects and short-term clinical outcomes. Seven males and five females were included in this study, mean age 42.16 years. For ten of them, it was the first embolization treatment; two had been previously treated with Onyx® embolization. PHIL® was injected with a transarterial approach without other embolics during the same procedure. Lesions were localized in small bowel (1), colon (1), head face (5), forefoot (1), uterus (1) and thorax (3); all were symptomatic. After 30-day clinical follow-up, a contrast-enhanced CT or MR was acquired at 3 months from intervention to detect eventual lesion residual. After a single embolization procedure, complete technical success was obtained in 50%, while clinical improvement without additional therapies was appreciable in all patients. No technical failure occurred; in two cases, a small amount of PHIL® proximally refluxed in nontarget vessels without clinical effects. No tattooing effects of superficial lesions neither artifacts at CT and cone-beam CT controls were evident. PHIL® seems to be a safe and effective liquid embolic agent for the treatment of peripheral AVMs and fistulas; although a direct comparison between PHIL and Onyx was not performed, PHIL might present the advantages of reduced artifacts at postprocedural CT scan and no need for shaking time preparation, but it is more expensive due to lower volume of product for each package and slightly less radiopaque at fluoroscopy.