Thrombus-in-Transit Following Watchman Device Implantation.

Thrombus-in-transit crossing an interatrial communication is a rare but potentially serious clinical condition, which has so far not been described after implantation of left atrial appendage (LAA) closure devices. Here, we describe the case of a 76-year-old woman with permanent atrial fibrillation and contraindication for oral anticoagulation therapy, who developed pericardial tamponade and acute pulmonary embolism with visible thrombus-in-transit formation following LAA closure. Most likely manipulation of the Watchman device in the LAA during two failed attempts in device positioning led to pericardial tamponade and venous puncture, manual compression after completion of the procedure and further immobilization resulted in deep vein thrombosis with consecutive pulmonary embolism and thrombus-in-transit formation. This case highlights the value of echocardiography after LAA closure.