Pictoral review of the endovascular treatment of pulmonary arteriovenous malformation

1.      Review the etiology, classification, and clinical presentation of pulmonary arteriovenous malformations (PAVMs)

2.      Compare the different types of endovascular devices used to treat PAVMs

3.      Review the most recent literature on the treatment of PAVMs

Background:

PAVMs are rare direct pulmonary artery-to-vein connections without intervening capillary beds, leading to right-to-left shunting or hemorrhage. Most PAVMs are congenital, approximately 70% -90% of patients have hereditary hemorrhagic telangiectasia. Acquired PAVMs commonly happen in the setting of cirrhosis, trauma, post-surgical, and others. Patients with PAVMs are usually asymptomatic but can present with dyspnea and fatigue. Complications of PAVMs include paradoxical embolization, leading to stroke, transient ischemic attack or brain abscess. We will provide a pictorial review of the different types of PAVMs.

Clinical Findings/Procedure Details: Endovascular tools used to treat PAVMs include detachable balloons, coils, or plugs. Traditionally, the distal aspect of the feeding artery beyond significant branches supplying the lung yet proximal to the venous sac is embolized. However, most recent meta-analysis and systematic review showed that venous sac embolization with or without feeding artery embolization is superior when compared to feeding artery embolization alone in the management of PAVMs {1}. We will provide pictorial case examples from the literature and institutional experience to help show the different embolization methods. This will include an introduction to the different catheters designed to access the pulmonary circulation and help subselect vessels. In addition, we will also demonstrate how to deploy the different embolic devices.

Conclusion and/or Teaching Points:

Most recent literature showed that venous sac embolization with or without feeding artery embolization is more efficacious than feeding artery embolization alone. Currently, vascular plug embolization is being utilized more as an endovascular therapy, which shows greater promise due to lower rates of recanalization. Further literature has complicated the effect of embolics in PAVMs. There are still many questions unanswered for PAVM treatment, including the goals of therapy, implications of persistence and which technique is superior, etc. We hope to highlight and provide the most up-to-date technical and procedural aspects of PAVM embolization in an easy-to-read pictorial format.