Transvenous Doppler guidewire sonographic monitoring during treatment of a complex vertebral arteriovenous fistula associated with neurofibromatosis Type 1

A Doppler sonographic guidewire was used to monitor incremental changes in draining vein (DV) flow during endovascular occlusion of a complex vertebral arteriovenous fistula (AVF) in a patient with neurofibromatosis type 1, Transvenous monitoring of average peak velocity (APV) and the maximum-minus-minimum peak velocity (MxPV-MnPV) demonstrated a progression from a highly pulsatile, fast flow before embolization to a nonpulsatile, slow now indicating a successful occlusion of the AVF (hemodynamic endpoint of treatment). Prior to this, apparent angiographic occlusion of the AVF was thought to signify a successful end-point: however, persistently elevated values for APV and MxPV-MnPV in the DV signalled the presence of an additional contralateral arterial contribution. Transvenous monitoring of flow velocity appears to be ideally suited to establishing a hemodynamic endpoint of embulotherapy in the presence of complex arteriovenous shunting, as may occur with the vasculopathy of neurofibromatosis.