Chronic arteriovenous fistulas masquerading as arteriovenous malformations: diagnostic considerations and therapeutic implications.

Arteriovenous fistulas (AVFs) and arteriovenous malformations (AVMs) may be difficult to differentiate angiographically, and this differentiation has important therapeutic implications. In five cases of chronic AVF, four originally misdiagnosed as AVMs, superselective angiography enabled the correct diagnosis. In two plantar arch fistulas, the technique was further enhanced by manual compression of arterial inflow to decrease the rate of blood flow through the fistula. All five AVFs were successfully occluded. The authors conclude that AVFs and AVMs can be distinguished by means of the appropriate angiographic techniques.