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Updated: Oct 3, 2025
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
Comparison of left atrial appendage parameters using computed tomography vs. transesophageal echocardiography for
Yasar Sattar1, Ritika Kompella2, Bachar Ahmad3
1Department of Cardiology, West Virginia University, Morgantown, Wv, USA.
Insights
Computed tomography (CT) provides larger left atrial appendage (LAA) measurements than transesophageal echocardiography (TEE) for Watchman device implantation. CT improves device sizing accuracy and reduces fluoroscopy time, with no impact on clinical outcomes.
Area of Science:
- Cardiology
- Medical Imaging
- Interventional Procedures
Background:
- Inaccurate sizing of left atrial appendage (LAA) occlusion devices, such as the Watchman device, is linked to increased stroke risk.
- Optimal device selection requires precise LAA anatomical assessment.
Purpose of the Study:
- To compare the accuracy of LAA size measurements between computed tomography (CT) and transesophageal echocardiography (TEE) for Watchman device implantation.
- To evaluate the impact of imaging modality on predicting correct device size and procedural outcomes.
Main Methods:
- A systematic literature search was conducted to identify studies comparing LAA measurements and procedural outcomes using CT versus TEE for Watchman implantation.
- Meta-analysis was performed on data from seven studies involving 242 patients assessed by TEE and 232 by CT.
Main Results:
- CT consistently yielded larger LAA orifice measurements compared to TEE (mean difference 0.30 mm, max difference 0.69 mm).
- CT, including 3D models, demonstrated higher odds of predicting the correct Watchman device size (OR 1.64).
- CT imaging was associated with significantly reduced fluoroscopy time (SMD -0.78 min).
Conclusions:
- CT imaging offers superior LAA size assessment compared to TEE for Watchman device implantation.
- Utilizing CT for LAA occlusion procedures can enhance device sizing accuracy and procedural efficiency.
- No significant differences in clinical outcomes were observed between the imaging modalities.
Background:
Inaccurate sizing of left atrial appendage (LAA) occlusion devices is associated with increased stroke risk. We compared the LAA size to implant the Watchman device assessed by computed tomography (CT) to transesophageal echocardiography (TEE).
Methods:
Databases were searched to identify studies comparing LAA anatomical measurements and procedural outcomes across imaging modalities for the Watchman device implantation.
Results:
Seven studies were included in the analysis (242 patients on TEE, and 232 on CT). The LAA orifice was larger when sized with CT compared to TEE (CT mean vs TEE SMD 0.30 mm, 95%CI 0.09-0.51 mm, P < 0.01; and CT max vs TEE SMD 0.69 mm, 95%CI 0.51-0.87 mm, P < 0.001). Additionally, CT, including CT-based 3-dimensional models, had higher odds of predicting correct device size compared to TEE (OR 1.64; 95%CI 1.05-2.56; P = 0.03). CT resulted in a lower fluoroscopy time vs TEE (SMD -0.78 min, 95% CI -1.39 to -0.18, P = 0.012). No significant differences were found in device clinical outcomes.
Conclusion:
Compared to TEE, CT resulted in larger LAA orifice measurements, improved odds of predicting correct device size, and reduced fluoroscopy time in patients undergoing LAA occlusion with the Watchman device. There were no significant differences in other procedural outcomes.
