Elongated Channels Between Surgically Excluded LAA and LA: Detected by CTA But Missed by TEE.

BACKGROUND: Systematic left atrial appendage (LAA) exclusion during mitral valve surgery reduces thromboembolic risk in patients with pre- or postoperative atrial fibrillation. Rare residual LAA-left atrial (LA) communications may occasionally occur after surgical exclusion and increase thromboembolic risk, particularly in patients not receiving anticoagulation. CASE SERIES: Among more than 2,000 robotic mitral valve surgeries performed at NYU Langone Health from 2010 to 2025, LAA closure with LA posterior wall plication was performed using a continuous back-and-forth suture technique. We identified 4 patients with elongated residual LAA-LA communications that were occult on transesophageal echocardiography (TEE) but clearly visualized by cardiac computed tomography angiography (CCTA). TEE demonstrated persistent echolucency and color Doppler flow within the excluded LAA without a visible communication entrance. A tubular channel extending from the LAA, termed the "panhandle sign," was consistently observed. CCTA identified the communication orifices and guided successful transcatheter vascular plug closure. CONCLUSIONS: Rare elongated residual LAA-LA communications may be missed on routine TEE after LAA exclusion with LA plication. Persistent LAA flow and echolucency should prompt CCTA to detect occult communications and guide percutaneous closure. The "panhandle sign" may represent an imaging marker specific to our institutional extended-suture technique that facilitates earlier recognition.