Systemic Artery to Pulmonary Artery Fistula Associated with Mitral Regurgitation: Successful Treatment with Endovascular Embolization

We present the case of a 60-year-old woman with symptomatic mitral regurgitation caused by a left-to-right shunt via anastomoses consisting of microfistulae, most likely of inflammatory origin, between the right subclavian artery and the right pulmonary artery. The three arteries responsible for fistulous formation, including the internal mammary, thyrocervical, and lateral thoracic arteries, were successfully occluded by transcatheter embolization using superabsorbent polymer microsphere (SAP-MS) particles combined with metallic coils. No complications have been identified following treatment with SAP-MS particles. This approach significantly reduced the patient's mitral regurgitation and she has remained asymptomatic for more than 4 years.