Speech Bubble Sign—Insights Regarding Incomplete Left Atrial Appendage Closure via Electrocardiography-Synchronized Computed Tomography in Robotic Surgery Cases

OBJECTIVES: In atrial fibrillation (AF), surgical management of the left atrial appendage (LAA) is crucial to prevent stroke. However, incomplete closure poses a residual embolic risk. METHODS: We retrospectively analyzed patients who underwent LAA closure using a continuous polypropylene suture technique during mitral valve surgery with the da Vinci system. Closure completeness was assessed via electrocardiogram-gated computed tomography (CT), and 3 D imaging was used to localize incomplete sites. RESULTS: Of 125 patients, 100 underwent postoperative CT. Complete closure (cLAA) was achieved in 76%, while 24% had incomplete closure (iLAA), typically at the mitral valve junction or suture start. These showed a characteristic "speech bubble" appearance. iLAA was associated with tricuspid valve repair and low V1 f-wave amplitude. Stroke rates were similar between groups over 24 months. CONCLUSIONS: Incomplete LAA closure occurred in 24% of cases despite direct visualization using robotics. Anatomical factors likely contribute more than technique alone. For high-risk patients with long-standing AF, techniques such as lumen crushing or external clips may enhance closure success. Further refinements are needed to improve the reliability of internal LAA closure methods.