Timing of doppler examination for the detection of arteriovenous fistula after percutaneous renal biopsy

Percutaneous renal biopsy is frequently performed, and postbiopsy arteriovenous fistula (AVF) formation is not uncommon. In most cases, it is asymptomatic and remains undiagnosed, because Doppler examination is not performed routinely. We describe 2 cases of postbiopsy AVF of the kidney that were detected 61 and 17 months after renal biopsy, respectively. The subsequent superselective transcatheter arterial embolization was successful in both cases. An undetected AVF of the kidney can progress and lead to serious consequences. A follow-up Doppler examination of the kidney soon after renal biopsy and 6 months later is recommended for early detection of nonresolving AVFs to prevent further complications.