First-in-human left atrial appendage closure using the WATCHMAN FLX Pro device: a case report

Background: Device-related thrombosis (DRT) is a known complication to left atrial appendage closure (LAAC). The surface of a LAAC device should ideally have antithrombotic properties. The novel WATCHMAN FLX Pro (WFP) incorporates a fluoropolymer-coated fabric membrane designed to increase thromboresistance and facilitate endothelialization. Such features could potentially allow for a minimal post-procedural antithrombotic regimen. Radiopaque platinum markers at the device shoulders and a large 40 mm device are other novel features of the WFP. Case summary: -weighted scan, used for visualization of fresh thrombus, suggested this to represent tissue ingrowth rather than thrombus. Discussion: The advanced follow-up imaging protocol suggested a good WFP implantation result with signs of tissue ingrowth at 45 days. The added radiopaque markers facilitated optimal deployment, evaluation of device stability during tug test, and assessment of device protrusion into the LA.