B46-26 Fatemeh Abbasi, MD Interventional Pulmonary Fellow

Abstract Massive hemoptysis is a life-threatening emergency, with a mortality of 10-40% despite current endovascular therapies. Bronchial arteries are the most common site of bleeding in massive hemoptysis, accounting for 90% of reported cases. The other remaining cases arise from non-bronchial systemic arteries and, rarely, the pulmonary arteries. Among all non-bronchial sources, the inferior phrenic artery is a rarely documented site of hemorrhage. A systemic-to-pulmonary venous fistula is even more exceptional. We present a unique case of recurrent massive hemoptysis in the setting of an inferior phrenic artery to right lower lobe pulmonary vein fistula, which was successfully treated with coil embolization. A 74-year-old male, chronically anticoagulated with apixaban for atrial fibrillation, presented initially with scant hemoptysis after multiple recent hospitalizations for recurrent pneumonia. Computed tomography angiography revealed a right lower lobe consolidation containing a 0.5 cm focus of contrast, consistent with extravasation or pseudoaneurysm. The Interventional Radiology team completed angiography that identified abnormal communication between the right inferior phrenic artery and the right lower lobe pulmonary vein, consistent with a systemic-to-pulmonary venous fistula. The IR team then completed embolization with four metallic coils, and hemostasis was achieved before discharge. Four days later, the patient had recurrent hemoptysis after resuming apixaban and was readmitted to the hospital. Repeat CTA did not identify any new contrast extravasation, and no active bleed was found on re-evaluation. Inferior phrenic artery-related hemoptysis is a rare but recognized pathology that most often involves systemic-to-pulmonary arterial shunts. Our reported case of an inferior phrenic artery to pulmonary vein fistula is exceedingly rare based on the currently available literature. Given no prior history of hemoptysis, we suspect that the patient acquired this fistula via post-infectious neovascularization in the setting of pneumonia and possible lung abscess. Follow-up management after coil embolization was complicated by the risk of re-bleeding with resumption of his anticoagulation for atrial fibrillation. This case presents a rare but treatable source of massive hemoptysis. Awareness of similar anatomical abnormalities as bleeding sources is vital for prompt diagnosis and intervention in patients with similar risk factors. This abstract is funded by: NA