Cardioembolism after thoracoscopic left atrial appendage clipping in a patient on oral anticoagulation therapy

Cardioembolism associated with atrial fibrillation is a major cause of ischemic stroke. Left atrial appendage occlusion in atrial fibrillation patients undergoing cardiac surgery reduces the risk of postoperative stroke. A 78-year-old man with a history of atrial fibrillation and severe mitral regurgitation underwent thoracoscopic mitral valve repair with left atrial appendage clipping and the cryo-maze procedure 4 years previously. He was taking a direct oral anticoagulant for stroke prevention because his atrial fibrillation had recurred. He presented with acute onset disturbed consciousness, omnidirectional gaze palsy, left facial palsy, severe dysarthria, bilateral limb ataxia, and sensory disturbance. National Institutes of Health Stroke Scale score was 16. Although non-contrast computed tomography showed no early ischemic changes, computed tomography angiography revealed occlusion of the basilar artery. Intravenous thrombolysis was performed, which resulted in recanalization. Transesophageal echocardiography showed left atrial spontaneous echo contrast and thrombus in the left atrial appendage. Contrast-enhanced chest computed tomography confirmed incomplete left atrial appendage occlusion. Cardioembolic stroke was diagnosed, and warfarin was initiated. Cardioembolism may occur after thoracoscopic left atrial appendage clipping despite direct oral anticoagulant therapy, particularly if appendage occlusion is incomplete. Occlusion status should be evaluated after thoracoscopic clipping.