Nongalenic pial arteriovenous fistula: Prenatal diagnosis.

Pial arteriovenous (AV) fistulae have rarely been diagnosed in utero. They are characterized by one or more pial arteries flowing directly into a cortical vein without any shunt or interposed capillary bed. In the fetus and the newborn up to 2 years of age, the most common clinical manifestation is heart failure resulting from fistula overload. Later on, hydrocephalus, focal neurologic deficits, headaches, seizures, and cerebral hemorrhage are the most common manifestations. We present a case of nongalenic pial AV fistula diagnosed in the 25th week of pregnancy, which resulted in intrauterine fetal death due to congestive heart failure.