Renal arteriovenous fistula with rapid blood flow successfully treated by transcatheter arterial embolization: application of interlocking detachable coil as coil anchor.

A 70-year-old woman presented to our outpatient clinic with a large idiopathic renal arteriovenous fistula (AVF). Transcatheter arterial embolization (TAE) using interlocking detachable coils (IDC) as an anchor was planned. However, because of markedly rapid blood flow and excessive coil flexibility, detaching an IDC carried a high risk of migration. Therefore, we first coiled multiple loops of a microcatheter and then loaded it with an IDC. In this way, the coil was well fitted to the arterial wall and could be detached by withdrawing the microcatheter during balloon occlusion ("pre-framing technique"). Complete occlusion of the afferent artery was achieved by additional coiling and absolute ethanol. This technique contributed to a safe embolization of a high-flow AVF, avoiding migration of the IDC.