Extravascular injection of sclerotic agents does not affect vessels in the rat: experimental implications for percutaneous sclerotherapy of arteriovenous malformations.

Sclerotherapy is useful for the treatment of arteriovenous vascular malformations. However, intravascular administration of sclerotic agents into small arteriovenous niduses is often difficult. Extravascular administration of sclerotic agents causes reduction of vascular flow on Doppler echo during clinical sclerotherapy. Therefore, we aimed to investigate whether the extravascular injection of sclerotic agents affects tiny vessels. Animal study. The effect of extravascular injection of sclerotic agents on vessels was investigated using rat femoral and superficial inferior epigastric vessels. After surgical exposure of vessels, absolute ethanol, 5% ethanolamine oleate and 3% polidocanol were injected into perivascular surrounding tissues, and their effect on vessels was evaluated after 14 days using histology and coloured silicone rubber injection. The integrity of the vascular lumen, endothelial cells and vascular patency were not affected by injection of sclerotic agents. Attenuation of vascular flow of an arteriovenous shunt after extravascular injection of sclerotic agents is transient and/or trivial and does not cause disruption of vessels. Therefore, sclerotic agents should be delivered to obtain sufficient destruction of arteriovenous malformation lesions and blood flow.