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.