Abstract
Coronary sinus atrial septal defect (CS‑ASD) is an uncommon congenital anomaly that accounts for <1% of all atrial septal defects. Over the past decade, around 10 adult CS‑ASD cases have been reported, and none have included simultaneous left ventricular (LV) thrombectomy. We describe the case of a 71‑year‑old man who presented with chest pain and ST‑segment‑elevation myocardial infarction caused by proximal right coronary artery occlusion, which was successfully treated with stent placement. Subsequent cardiac examination revealed CS-ASD and LV thrombosis. Using an endoscopic approach, we successfully repaired the defect and removed the thrombus. Because the defect lacked an adequate surrounding rim and a transcatheter device could jeopardize coronary‑sinus patency, percutaneous closure was deemed contraindicated, and thus surgical patch repair was undertaken. Endoscopic surgery performed via a right mini‑thoracotomy afforded excellent exposure of the atrial septum and LV cavity while being less invasive and allowing sternal preservation, thereby facilitating an expedited postoperative recovery, advantages that are particularly pertinent when concomitant CS‑ASD closure and LV thrombectomy are required.