E5361. Imaging and Endovascular Treatment Approach to Persistent Pulmonary Arteriovenous Malformations
  1. Chinmay Kulkarni; No Affiliation
  2. Patrick Sutphin; No Affiliation
  3. Shams Iqbal; No Affiliation
  4. Sanjeeva Kalva; No Affiliation
Pulmonary arteriovenous malformations (PAVMs) are abnormal high-flow communications between pulmonary arteries and pulmonary veins. Complications are more common in untreated PAVMs compared to treated PAVMs and can sometimes be life-threatening. Hence early detection and treatment of PAVM becomes critical. Endovascular embolotherapy is the initial treatment of choice for PAVMs. However, 2–25% of successfully treated PAVMs show persistence and warrant retreatment.

Educational Goals / Teaching Points
1. Understand the mechanisms and patterns of PAVMs. 2. Understand the imaging and endovascular treatment approach to persistent PAVMs.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Symptoms of persistent PAVMs are most commonly due to the shunting of deoxygenated blood from the pulmonary to the systemic circulation. Various factors that influence the persistence of PAVMs are type of PAVM, progression of the underlying disease and angioarchitecture. Recanalization is the common pattern of persistence. Imaging is crucial to diagnose persistent PAVM and plan the embolotherapy. Patients with treated PAVMs are initially scanned by bubble ECG, which is a sensitive noninvasive tool that can be helpful in early detection of persistent PAVMs. The patients with a positive result on bubble ECG need further evaluation with contrast-enhanced CT. CT imaging allows for a detailed analysis of the angioarchitecture of PAVM and planning for embolization of complex persistent PAVMs. Symptomatic PAVMs, persistent patency of the aneurysm sac, and progressive enlargement and development of complications secondary to paradoxical embolization are indications for retreatment. The embolization technique and choice of embolizing agents depend on the vessel anatomy and hemodynamics. Embolization is performed using coils, vascular plugs, liquid embolic, or a combination of these embolic agents. Treatment outcomes are better in recanalized PAVMs compared to reperfused persistent PAVMs.

Persistent PAVM occurs due to varied mechanisms and is challenging to treat. Advancements in catheter and embolic device technology and a better understanding of the hemodynamics of PAVM due to improved imaging will lead to better endovascular treatment outcomes.