Graded Transthoracic Contrast Echocardiography After Pulmonary Arteriovenous Malformation Embolization: Can Chest CT Be Avoided in Patients With a Low-Grade Shunt?

Abstract

BackgroundPulmonary arteriovenous malformations (PAVMs) are direct connections between the pulmonary artery and vein, creating right-to-left shunting (RLS). Embolization is indicated to prevent complications. Guidelines recommend follow-up chest CTs to confirm persistent occlusion and embolization of all treatable PAVMs. Graded transthoracic contrast echocardiography (TTCE) after PAVM embolization may offer a reliable alternative in a subgroup of patients while preventing radiation exposure. Research questionCan TTCE predict the need for additional embolotherapy in the post-embolization population as accurately as it does in treatment-naïve population? Study design and methodsSince 2018, follow-up after PAVM embolization at the study institution includes both TTCE and chest-CT after 6-12 months and every 3-5 years thereafter. Patients who underwent at least one follow-up TTCE and chest-CT were included. The indication for additional embolotherapy was discussed in a multidisciplinary team meeting. The primary outcome was the indication for additional embolotherapy in each RLS-grade. Additionally, the association between the RLS-grade and indication for additional embolotherapy was investigated. Results339 patients with 412 embolization procedures were included, median time to follow-up TTCE was 7.5 months. A RLS was present in 399 post-embolization TTCEs (97%): RLS grade 1 in 93 patients (23%), grade 2 in 149 patients (36%) and grade 3 in 157 patients (38%). In patients with a RLS grade 0-1, no treatable PAVMs were found on CT. In patients with RLS grade 2-3, 22 (15%) and 72 (46%) underwent additional embolizations. InterpretationThis study shows chest CT might be forgone in patients with an RLS grade 0-1 after PAVM embolization.