Arteriovenous fistula after biopsy of renal transplant: detection and monitoring with color flow and duplex ultrasonography.

An asymptomatic intrarenal arteriovenous fistula was incidentally discovered by color flow and duplex ultrasonography approximately 2 weeks after a percutaneous biopsy of a renal allograft. On the basis of information obtained from the color flow image and pulsed Doppler analysis, the vascular communication could be characterized without the need for angiographic correlation. The patient was managed successfully with close observation aided by serial ultrasound examinations. Spontaneous resolution of the fistula occurred within 4 weeks after the biopsy and was evident on a follow-up ultrasound examination. Duplex ultrasonography in conjunction with color flow imaging proved to be a valuable noninvasive technique for diagnosing and monitoring this postbiopsy vascular complication.