Procedural Details
The procedure was performed under general anesthesia. Femoral venous access was obtained using the Seldinger technique with a micropuncture needle under ultrasound guidance. A transesophageal echocardiogram (TEE) was performed to document the absence of LAA thrombus, define LAA anatomy, and guide the transseptal puncture as well as device implantation. Echo contrast was not required for any of these studies. Transseptal access was performed in the lower, anterior quadrant of the fossa ovalis. Heparin was given prior to transseptal puncture with a goal activated clotting time (ACT) > 250 seconds. Procedural details specific to the different devices used for LAA closure are provided in the Results section. After device deployment, device position and LAA occlusion were verified by TEE and contrast injection. TEE was performed at 6 weeks after the procedure to confirm LAA occlusion.
For the WATCHMAN leak closure, a CT-derived (0.977 mm pixel size x 1.5 mm spacing) 3D printed model was prepared. Segmentation was performed using 3D Slicer software (Brigham and Women’s Hospital, Boston, MA): a 5 mm thickened shell model was generated from the contrast-defined volume of the LA and LAA and a model of the WATCHMAN was created using a higher HU threshold (Figure 3). Manual adjustment was used for both elements to improve model quality. Models were printed with a Stratasys Eden 260V printer in FLX930 and RGD720 flexible and rigid resins respectively (Stratasys, Ltd., Rehovot, Israel). The model was used to determine and test the correct type and size of the closure device.