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A7055 - Systemic Artery to Pulmonary Artery Fistula Misdiagnosed as Pulmonary Embolism
Author Block: A. Siddiqui1, S. Sahay2, J. Gibbs3; 1Division of Pulmonary and Critical Care Medicine, Houston Methodist Hospital, Houston, TX, United States, 2Division of Pulmonary Medicine, Houston Methodist Hospital/Weill Cornell Medical College, Houston, TX, United States, 3Radiology, Houston Methodist Hospital, Houston, TX, United States.
INTRODUCTION:
Systemic artery to pulmonary arterial fistulas (SAPAF) can develop in patients with congenital heart disease. However, they are very rare in the general population. We report a case of right inferior phrenic artery and right lower pulmonary artery fistula presenting as dyspnea and tachycardia that was misdiagnosed as acute pulmonary embolism.
CASE PRESENTATION:
A 33 year old female with past medical history of asthma was evaluated in clinic for shortness of breath. She was diagnosed with pulmonary embolism four years ago and treated with anticoagulation for six months. There was no associated sputum production, fever, chills, chest pain or hemoptysis. Her physical exam was unremarkable except for sinus tachycardia. Echocardiogram showed normal ejection fraction, normal left and right ventricular chamber size, wall thickness and function, and no valvular abnormalities. Six minute walked distance was 392 meters without oxygen desaturation. CT angiogram of the chest showed systemic artery to pulmonary artery fistula in the right lower lobe. A dilated right inferior phrenic artery was seen supplying the vascular malformation in the right lower lobe, measuring approximately 1.9 x 1.1 cm, draining into the right lower lobe branch of the pulmonary artery with diminished enhancement of pulmonary artery branch due to retrograde flow. Angiogram of the chest showed a complex vascular malformation supplied by the right inferior phrenic artery branches and draining into a dilated branch of the right lower lobe pulmonary artery. The patient underwent successful embolization of the right inferior phrenic artery to pulmonary artery fistula using an arterial to arterial approach with onyx embolization material and coils by intervention radiology. She was followed up in clinic with resolution of symptoms.
DISCUSSION:
SAPAF are generally asymptomatic, but potential complications may include infection, hemorrhage, pulmonary artery hypertension and congestive heart failure. The natural course and indications for treatment have not been established. Surgical intervention used to be the mainstay of treatment but recently, embolization has become the preferred treatment option since loss of lung parenchyma and function is minimal. SAPAF presenting as pulmonary embolism has never been reported. In our case, the patient was diagnosed with pulmonary embolism involving right segmental branches of the pulmonary artery and was treated with anticoagulation for six months but it was corrected successfully using onyx embolization material and coils. SAPAF are very rare, and transcatheter embolization is a feasible therapeutic option.