Acquired Coronary Artery Fistulas in Metastatic Renal Cell Carcinoma: A Case Report

Coronary artery fistulas (CAFs) are a rare, typically congenital coronary anomaly. They may cause myocardial ischemia through a coronary steal phenomenon. Acquired CAFs are exceptionally uncommon and are usually due to an intervention or trauma. We re-port the case of a 79-year-old man with history of clear cell renal cell carcinoma previ-ously treated with right nephrectomy in 2015. Seven years later, he underwent percu-taneous coronary intervention of severe LAD stenosis following out-of-hospital cardi-ac arrest. During follow-up, progressive exertional dyspnea and inducible lateral is-chemia led to repeated coronary angiography 15 months later revealing fistulous communications from the circumflex and right coronary arteries draining into a left pulmonary mass. Right-heart catheterization showed a small left-to-right shunt at rest (Qp/Qs 1.3). Thoracic computed tomography and biopsy confirmed a large pulmonary metastasis from clear cell renal cell carcinoma, suggesting that the fistulas developed as part of tumor angiogenesis. Transcatheter coil embolization would have been a strategy to reduce tumor perfusion and the coronary steal; however, we just limited our treatment to the tyrosine kinase inhibitor Axitinib due to the metastatic disease. This case describes a rare mechanism of acquired CAF formation in metastatic renal cell carcinoma.