Color Doppler Ultrasonography to Verify the Closure of Dural AV Fistulae After r-Knife Radiosurgery

Abstract

Purpose To evaluate the role of color Doppler ultrasonography (CDUS) in verifying the closure of a dural arteriovenous (AV) fistula after r-knife radiosurgery (GKRS). Materials and Methods A total of 22 patients with dural AV fistulae, superior ophthalmic vein (SOV) drainage, and who had undergone GKRS therapy were followed up with CDUS until the closure was confirmed. The CDUS method was a trans-orbital scan with a focus on the evaluation of the SOV. The SOV was classified into three grades according to its velocity: severe, moderate and mild. All patients received angiography to confirm the findings of the CDUS. Results Before GKRS, CDUS revealed a reversed pulsatile flow (10 right SOVs, 8 left SOVs, and 4 bilateral SOVs). Six patients were graded as severe, eight as moderate, and eight as mild. All patients had their closure confirmed by CDUS, which was then further validated with angiography. Conclusion CDUS is an excellent modality for monitoring the hemodynamic changes in the SOV of patients with dural AV fistula following GKRS therapy. CDUS may become the modality for follow-up until complete closure occurs.