Natural history of congenital arteriovenous fistula.

There is no more difficult lesion to manage than congenital arteriovenous fistula. The advanced lesions are extremely vascular and unless they lend themselves to total excision, prompt recurrence is the rule. For the same reason, embolization is not successful and as the major feeding vessels are occluded, access to the tumor becomes more and more limited. In order to obliterate the tumor, it must be destroyed at the microvascular level. So far, only ethanol has proved effective in this regard, and this agent must be used conservatively to avoid excessive destruction of normal tissue and systemic damage.