Embolization of Recurrent Pulmonary Arteriovenous Malformations by Ethylene Vinyl Alcohol Copolymer (Onyx®) in Hereditary Hemorrhagic Telangiectasia: Safety and Efficacy

Abstract

Objectives: To evaluate short- and long-term safety and efficacy of embolization with Onyx^® for recurrent pulmonary arteriovenous malformations (PAVMs) in hereditary hemorrhagic telangiectasia (HHT).

Methods: In total, 45 consecutive patients (51% women, mean (SD) age 53 (18) years) with HHT referred to a reference center for treatment of recurrent PAVM were retrospectively included from April 2014 to July 2021. Inclusion criteria included evidence of PAVM recurrence on CT or angiography, embolization using Onyx^® and a minimal 1-year-follow-up CT or angiography. Success was defined based on the standard of reference criteria on unenhanced CT or pulmonary angiography if a recurrence was suspected. PAVMs were analyzed in consensus by two radiologists. The absence of safety distance, as defined by a too-short distance for coil/plug deployment, i.e., between 0.5 and 1 cm, between the proximal extremity of the primary embolic material used and a healthy upstream artery branch, was reported.

Results: In total, 70 PAVM were analyzed. Mean (SD) follow-up was 3 (1.3) years. Safety distance criteria were missing in 33 (47%) PAVMs. All procedures were technically successful, with a short-term occlusion rate of 100% using a mean (SD) of 0.6 (0.5) mL of Onyx^®. The long-term occlusion rate was 60%. No immediate complication directly related to embolization was reported, nor was any severe long-term complication such as strokes or cerebral abscesses.

Conclusions: In HHT, treatment of recurrent PAVM with Onyx^® showed satisfactory safety and efficacy, with an immediate occlusion rate of 100% and a long-term rate of 60%.

Keywords: Rendu–Osler–Weber disease; arteriovenous malformations; embolization; hereditary hemorrhagic telangiectasia; thorax.

Figure 1

Study flowchart.

Figure 2

Case examples of a 68-year-old man (A–C) and 48-year-old man (D–F) treated for a simple recurrent pulmonary arteriovenous malformation. In both cases, digital subtraction angiography unsubtracted images showed a distance >10 mm between the first coil and the aneurysmal sac, which is considered a risk factor for recanalization. (A–C). Embolization was performed using Onyx^® (0.3 mL) to fill the afferent artery in and downstream of the pre-implanted coils and resulted in an immediate complete occlusion, maintained after 23 months follow-up. No leak in the aneurysm or in the vein was reported. (A). Opacification of the afferent artery showed a recanalization through the pre-implanted coils (full arrowhead). (B). Opacity within, downstream and upstream of the coils (empty arrowheads) showed the distribution of Onyx^® without any evidence of a leak in the aneurysmal sac. (C). Opacification of the afferent artery showed the absence of opacification of the aneurysmal sac and the efferent vein in favor of immediate occlusion. The opacification of the healthy arterial branch did not reveal any perfusion defect. (D–F). Embolization was performed using Onyx^® (0.4 mL) to fill the afferent artery in and downstream of the pre-implanted coils and resulted in an immediate complete occlusion, with a recurrence 36 months after the procedure. No leak in the aneurysm or in the vein was reported. (D). Opacification of the afferent artery showed a recanalization through the pre-implanted coils (full arrowhead). (E). Opacity within, downstream and upstream of the coils (empty arrowheads) showed the distribution of Onyx^® without any evidence of a leak in the aneurysmal sac. (F). Opacification of the afferent artery showed the absence of opacification of the aneurysmal sac and the efferent vein in favor of immediate occlusion.

Figure 3

Case example of a 57-year-old woman treated for a simple recurrent pulmonary arteriovenous malformation (PAVM) in the lower left lobe. Digital subtraction angiography unsubtracted images showed a distance between the last coil and a healthy arterial branch too short to add additional coils. Embolization was thus performed using Onyx^® (0.4 mL) to fill the afferent artery within the pre-implanted coils and resulted in an immediate complete occlusion, maintained after 13 months follow-up. No leak in the aneurysm or in the vein was reported. A leak upstream the coils in the segmental artery was reported without any consequence on lung perfusion (empty arrowhead). (A). Opacification of the afferent artery of a PAVM showed a recanalization through the pre-implanted coils (arrowhead). (B). Opacity in the coils and afferent artery showed the distribution of Onyx^®, with an upstream leak in a segmental arterial branch (empty arrowhead). (C). Opacification of the afferent artery showed the absence of opacification of the aneurysmal sac and the efferent vein in favor of immediate occlusion. The opacification of the healthy arterial branch did not reveal any perfusion defect.

Figure 4

Case example of an 18-year-old man treated for a complex recurrent pulmonary arteriovenous malformation in the middle lobe. Digital subtraction angiography unsubtracted images showed a recanalization in two different segmental feeder arteries (A–F). Embolization was performed using Onyx^® (0.5 mL in each artery) to fill the afferent artery upstream and within the pre-implanted coiling and resulted in an immediate complete occlusion, maintained after 43 months follow-up. No leak in the aneurysm or in the vein was reported. (A). Opacification of an afferent artery (full head arrow) showed a recanalization through the pre-implanted coils. (B). Opacity upstream and in the last coil (empty arrowhead) showed the distribution of Onyx^® without any evidence of a leak in the aneurysmal sac or proximal arterial branch. (C). Opacification of the afferent artery showed the absence of opacification of the aneurysmal sac and the efferent vein in favor of immediate occlusion. The opacification of the healthy arterial branch did not reveal any perfusion defect. (D). Opacification of a second afferent (full head arrow) artery showed a recanalization through the pre-implanted coils. (E). Opacity upstream of the coils showed a leak of Onyx^® (empty arrowhead) without evidence of any leak in the aneurysmal sac. (F). Opacification of the afferent artery showed the absence of opacification of the aneurysmal sac and the efferent vein in favor of immediate occlusion. The opacification of the healthy arterial branch did not reveal any lung perfusion defect.

Figure 5

Case example of a 37-year-old woman treated for a simple recurrent pulmonary arteriovenous malformation in the lower right lobe. Embolization was performed using Onyx^® (0.5 mL) to fill the afferent artery within the pre-implanted coils and resulted in an immediate complete occlusion, maintained at 34 months follow-up. No leak in the aneurysm or in the vein was reported, but a leak in the upstream sub-segmental arteries was identified. (A). Opacification of the afferent artery showed a recanalization through existing coiling. (B). Opacity within and upstream of the pre-implanted coils (empty arrowheads) showed the distribution of Onyx^®, with a leak in a proximal arterial branch. (C). Opacification of the afferent artery showed the absence of opacification of the aneurysmal sac and the efferent vein in favor of immediate occlusion. An altered opacification in the upstream branch (full arrowhead) was identified due to the leak of Onyx^®. (D). The one-year follow-up chest CT showed a distal lung infarction related to embolization. Of note, the patient did not suffer from chest pain or pleural effusion after the embolization procedure.

Figure 6

Case example of a 35-year-old man treated for a recurrent simple pulmonary arteriovenous malformation in the right lower lobe. The pulmonary angiograph showed a distance between the last coil and a healthy arterial branch too short to add additional coils. Embolization was thus performed using Onyx^® (0.4 mL) to fill the afferent artery upstream and in the pre-implanted coils, without any leak neither in the aneurysm nor in the vein. It resulted in an immediate complete occlusion until 46 months after the procedure when a recurrence was reported. (A). Opacification of the afferent artery of a PAVM in the lower right lobe showing a recanalization through the pre-implanted coils. (B). Opacity in and upstream (empty arrowheads) the coils showing the distribution of the Onyx^®, without any evidence of a leak in the aneurysmal sac, but with a leak in the small arterial branches. (C). Opacification of the afferent artery showing the absence of opacification of the aneurysmal sac and the efferent vein in favor of immediate occlusion. A perfusion defect was identified in a sub-segmental territory (full head arrow), not related to a symptomatic lung infarction.