Progressive Giant Left Atrial Appendage Thrombus After Aborted Appendage Occlusion Despite Anticoagulation

Figures

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  Visual Summary. Clinical Timeline of Progressive Giant Left Atrial Appendage Thrombus Formation After Aborted LAAO, Highlighting Early Thrombus Suspicion, Progressive Enlargement Despite Continued Anticoagulation, Surgical Treatment, and Pathological Findings MICS = minimally invasive cardiac surgery.

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  Figure 1. Transesophageal Echocardiography During the Watchman Implantation Procedure Marked blood flow stagnation within the device is observed during provisional deployment.

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  Figure 2. Transthoracic Echocardiography on the Day After the Aborted Procedure A thrombus measuring 4.6 mm × 10.6 mm is suspected in the left atrial appendage (LAA) without obvious mobility.

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  Figure 3. Transesophageal Echocardiography Performed 98 Days After the Aborted Watchman Procedure A giant thrombus measuring 20 mm × 25 to 30 mm with high echogenicity and limited mobility is observed, partially protruding from the left atrial appendage.

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  Figure 4. Gross Appearance of the Surgical Specimen Obtained During Left Atrial Appendage Resection Pseudo-endocardial tissue is seen on the left side, the thrombus in the center, and the left atrial appendage wall on the right. The thrombus appears partially organized and loosely attached to the pseudo-endocardial tissue, forming a single mass.

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  Figure 5. Histopathological Examination of Surgical Specimens Obtained During Left Atrial Appendage Resection Performed 100 Days After the Aborted Watchman Procedure (A) Azan-stained low-power view demonstrating pseudo-endocardial tissue with marked fibrous thickening. (B) Higher-power view showing fibroblast infiltration and neovascularization within the pseudo-endocardial layer. (C) Hematoxylin-eosin staining showing a fibrin-rich thrombus with entrapped erythrocytes and inflammatory cell infiltration, consistent with a subacute thrombus.