Purpose: To examine the characteristics of recurrent pulmonary arteriovenous malformations (PAVMs) and compare the success of proximal versus distal embolization technique for treatment of recanalized PAVMs.
Materials: Between July 2007 and October 2018, 26 consecutive patients underwent embolization of 64 previously treated recurrent PAVMs at a single center with imaging follow-up. PAVM angioarchitecture was classified as either simple (1 feeding artery) or complex (≥ 2 feeding arteries). The mechanism of recurrence was characterized as recanalization (flow through previously placed embolic material) or reperfusion (flow through accessory arteries). For recanalized PAVMs, we compared embolizing proximal to or within the existing embolic (proximal embolization technique) versus embolizing distal to the existing embolic (distal embolization technique). Follow-up imaging was reviewed to determine treatment success, defined as decrease of the draining vein or sac size by at least 70%.
Results: Mean patient age was 47.6 years (range 22-72 years), and 61.5% were female. Twenty-four patients (92.3%) had hereditary hemorrhagic telangiectasia, a disorder associated with PAVM formation. 31/64 (48.4%) PAVMs were simple, and 33/64 (51.6%) PAVMs were complex. Recanalization was the most common pattern of recurrence, occurring in 54/64 (84.4%) PAVMs. Treatment success following repeat embolization was 54.7% at a mean follow-up time of 1.6 years. For recanalized PAVMs, treatment success was significantly more likely with distal embolization technique (14/15, 93.3%) than with proximal embolization technique (19/33, 57.6%) (P = 0.0180).
Conclusion: Recurrent PAVMs are difficult to treat, with high rates of recurrence following repeat embolization. Distal embolization technique is more likely to produce durable occlusion than proximal embolization.
Keywords: Embolization; Hereditary hemorrhagic telangiectasia; Pulmonary arteriovenous malformations; Recanalization; Reperfusion.