New Treatment Approaches to Arteriovenous Malformations

Abstract

Arteriovenous malformations (AVMs) are high-flow vascular anomalies that have demonstrated a very high recurrence rate after endovascular treatment, surgical treatment, or a combination of both. Surgical treatments have shown good response when they are small and well localized but a poor response when diffuse. A better understanding of the nature of the lesion has led to a better response rate and a safer treatment for these patients. This has been accomplished through a detailed understanding of the angioarchitecture of the lesion, enabling a tailored approach in reaching and targeting the nidus of the AVM with different liquid embolic agents, more specifically ethanol. Flow reduction techniques help in exposing the nidus to sclerosant agents. A clinical classification, the Schobinger classification, will help determine the appropriate time to start or to pursue therapy.

Keywords: arteriovenous malformation; embolization; ethanol injection; nidus destruction; vascular anomalies.

Fig. 1

Angiographic classification according to Cho et al.

Fig. 2

Angiographic classification according to Yakes and Baumgartner.

Fig. 3

( a ) CTA showing venous aneurysm from direct fistula. (b) Selective renal artery angiography with dilated vein and early enhancement of renal vein from at least two fistulas. ( c ) Coil embolization of the fistulas. ( d ) Follow-up angiography. ( e ) Follow-up CTA at 6 months confirming treatment of direct fistulas.

Fig. 4

( a, b ) A 50-year-old woman with foot AVM. ( c ). endovascular approach with distal microcatheter and ethanol injection. ( d ) Direct puncture of nidus. ( e ) Outflow compression to get better exposure of nidus to ethanol. ( f ) Final angiography with satisfactory result.

Fig. 5

( a, b ) Prominent pelvic AVM mainly from uterine artery and important dilated venous draining vein. ( c–e ) Endovascular approach and ethanol injection to decrease inflow. ( f ) Embolization with glue up to the venous sac with a proximal flow control with an occlusion balloon. ( g, h ) Final angiography shows complete resolution of AVM.

Fig. 6

( a ) Foot angiography with AVM involving first toe. (b, c) Distal selective angiography showing normal arteries at the tip of toe. ( d, e ) Protection of distal aspect of toe with tourniquet and ethanol injection through microcatheter and direct puncture. ( f ) Final run with normal aspect of distal toe and treatment of fistulas.

Fig. 7

( a–e ) A 40-year-old male patient presenting with priapism and nonhealing ulcer of penis from pelvic AVM draining in venous aneurysm and refluxing all the way to penile veins causing venous congestion. ( f ) Endovascular approach and filling of nidus of to the venous aneurysm with Onyx. ( g, h ) Patient asymptomatic at 2-month follow-up with absence of significant shunting on angiography.

Fig. 8

( a–d ) CTA of a 55-year-old male patient with intermittent bleeding that developed intractable abdominal pain for the past 3 weeks. AVM nidus in mesosigmoid with early draining veins and inferior mesenteric vein increased in size. Wall of sigmoid colon thickened with fat straining confirming ischemic changes. ( e–h ) Embolization with Onyx before surgical resection.

Fig. 9

( a ) Pelvic AVM draining into a prominent gonadal vein. (b, c) Feeding artery coming primarily from ovarian branch originating from renal artery. (d) Arterial endovascular approach and ethanol embolization to decrease the inflow. (e, f) Balloon occlusion to decrease outflow and further embolization with ethanol from microcatheter inserted through the balloon catheter. ( g ) Deployment of an Amplatzer plug to avoid thrombus migration. ( h ) Follow-up CTA confirming occlusion of AVM.

Fig. 10

( a ) MIP MRA showing a small but very symptomatic AVM in right labial region. (b, c) Angiography shows multiple feeding arteries that are very small in size. ( d, e ) Microcatheterization as deep as possible and injection with Onyx. ( f ) Follow-up angiography demonstrated a residual nidus at superior aspect too small for microcatheterization. ( g ) Direct puncture under ultrasound guidance and ethanol injection. ( h, i )Follow-up angiography demonstrates complete embolization.