Right atrial thrombus and pulmonary embolism one year after ventricular septal defect patch repair: successful surgical management of a complicated case.

BACKGROUND: Right heart thrombi are rare but life-threatening, with particularly high mortality when accompanied by pulmonary embolism (PE). Cardiac surgery may predispose to in-situ thrombus formation via suture lines or patch material, yet thromboembolic risk and preventive strategies following Ventricular Septal Defect (VSD) repair remain unclear. Here, we report a case of a young patient with a massive right atrial (RA) thrombus with PE one year after VSD repair in the absence of any known hypercoagulable state. CASE PRESENTATION: A 17-year-old male with a history of surgical VSD repair one year earlier, who was not taking any antithrombotic therapy prior to presentation, presented with acute dyspnea, tachycardia, and severe hypoxia. Transthoracic echocardiography revealed a large, freely mobile RA mass. Subsequent CT pulmonary angiography and cardiac magnetic resonance confirmed a massive right pulmonary artery embolus and characterized the RA mass as an intracardiac thrombus. Because of clinical deterioration despite therapeutic anticoagulation, he underwent a successful urgent cardiac surgery with RA mass excision and pulmonary embolectomy. Postoperative histopathology confirmed the mass to be a thrombus. CONCLUSIONS: Our case highlights a rare late RA thrombus with PE one year after surgical VSD repair, requiring urgent surgery. Further research is needed to clarify post-VSD closure surveillance and thromboprophylaxis strategies.