Transarterial embolization of a large high-flow right renal arteriovenous fistula using stents and an across-stent wire-trapping technique

Abstract

Renal arteriovenous fistulas (AVFs) are rare vascular abnormalities. Their high-flow nature may result in increased cardiac output and lead to heart failure. Transcatheter endovascular management of renal AVFs with various embolization materials has been the treatment of choice in recent years. Embolization of large renal AVFs poses a risk of embolization through the AVF to the pulmonary circulation. Herein, we present the case of a patient whose large high-flow renal AVF was treated by a novel method involving the use of a bare stent and detachable metallic coils-called a wire-trapping technique-as well as compare this method with vascular plugs.

Keywords: Across-stent wire trapping; Arteriovenous fistula; Transcatheter embolization.

Fig 1

Coronal computed tomography angiography image showing a large tortuous right renal arteriovenous fistula (AVF; arrow) with engorged inferior vena cava.

Fig 2

Aortogram showing a large tortuous right renal arteriovenous fistula (AVF; arrow) with early opacification of inferior vena cava, indicating high flow.

Fig 3

A, Right renal angiogram showing status after deployment of a bare-metal stent in the renal arteriovenous fistula (AVF), with a total of three catheters, including a VER catheter (arrow) for in-stent coil deployment and two Progreat microcatheters (arrowheads) for out-stent coil deployment. B, Contrast medium filling in the stent, indicating a 0.018-inch metallic coil out-in-out of the stent as a barrier (arrowhead) and a 0.035-inch metallic coil in the stent (arrow) trapped by the 0.018-inch coil. C, Multiple 0.035-inch metallic coils deployed in the stent and 0.018-inch metallic coils deployed outside the stent in the renal AVF, blocked by bare-metal stent without migration.

Fig 4

A, Final angiography. B, Follow-up computed tomography angiography showing complete occlusion of the arteriovenous fistula (AVF).

Fig 5

Step-by-step illustration of the wire-trapping technique. The red area indicates feeding branch of renal artery, and the blue area indicates drainage vein. A, Two preplaced microcatheters (dark blue thin catheters) from guiding catheter. B, Relationship of bare-metal stent and catheters, including two preplaced microcatheters and central VER catheter (central midsized catheter). C, Third microcatheter advanced from the VER catheter, through opposite sides of stent mesh. A 0.018-inch coil was deployed from this catheter and left in the path. D, After deployment of two 0.018-inch coils as in-stent barriers. E, Deployment of 0.035-inch coils in stent, entangled with in-stent barriers. F, Deployment of 0.018-inch coils outside the stent to fill the gap between stent and vessel. d-f, Demonstration of cross-sectional view corresponding to D-F.