Watchman Device - Oct 2024 Case of the Month

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A patient at risk for blood clots due to atrial fibrillation was recently referred to the 3DQ Lab for evaluation of an LAAC (Left Atrial Appendage Closure) device. Atrial fibrillation, a common type of heart arrhythmia, can pose a health risk due to its potential to form blood clots within the left atrial appendage (LAA). These clots can lead to severe complications like strokes, heart attacks, or pulmonary embolisms if they travel to other parts of the body. To mitigate this risk, LAAC devices such as the Watchman and Amulet are employed. These devices are designed to seal off the LAA, preventing blood from entering and thus, reducing the likelihood of clot formation.

Implantation of these devices involves preoperative planning and measurements, conducted through left atrial mapping scans to ensure fitting and effectiveness. The devices are typically implanted in a catheterization lab, using a minimally invasive procedure guided by real-time imaging and preoperative data.

Measurements for both LAAC devices were performed on a contrast-enhanced cardiac scan of the patient. Although both devices serve the same purpose, their design differences require unique measurement approaches for implantation. For the Amulet device, the measurements include the orifice diameter, landing zone depth, and the overall depth of the LAA. The Watchman device, meanwhile, requires assessment of the only the landing zone and depth, with slight variations in how these measurements are taken.

The choice between a Watchman or an Amulet device is based on the anatomical characteristics of the patient’s heart, of which additional images were provided as rotational movies and static images from multiple angles. The measurements of these anatomical characteristics helped clinicians decide on the Watchman device as the preferred option for this patient.

Volume Renderings and Curved Planar Reformations (CPRs) are also created to assist in preoperative planning. By segmenting the entire left atrium and appendage from the start of the pulmonary veins, the 3DQ Lab created a 3D model and rotational views of the target area. These views offered a perspective of the potential catheter’s path through the heart wall into the LAA during the procedure. Furthermore, the CPR views help visualize the best angles for device placement, offering a virtual endoscopic perspective inside the atrium which can be helpful for navigating the anatomical landscape during implantation.?

Three months post-operation, the same imaging techniques were employed to assess the device’s position, check for possible thrombus formation within the atrium, and assess the device for leaks. In this case a leak was detected, indicated by the presence of contrast inside the device. Leaks can compromise the device’s effectiveness in preventing blood from entering the LAA, thus maintaining a risk for clot formation. In situations like this, monitoring and temporary anti-coagulation therapy is performed until the tissue of the LAA grows around the device and seals the leak. Severe leaks may warrant additional intervention to reposition or replace the device.

Learn more about some of the techniques shown in this article:

Curved Planar Reformat (CPR) (2)

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