Abstract
A 74-year-old male with a history of cardioembolic stroke, chronic atrial fibrillation, and cerebral hemorrhage, who had undergone left atrial appendage closure using the WATCHMAN device 1 year prior, was diagnosed with a 25-mm intra-cardiac mass in the right atrium. The patient underwent the surgical removal of the right atrial mass and the explantation of the WATCHMAN device. The WATCHMAN device was explanted with an external incision at the base of the left atrial appendage, facilitating the removal of the device and the closure of the appendage through direct suturing. The pathological examination confirmed the right atrial mass to be a thrombus. The patient was discharged on postoperative Day 13. From the perspectives of simplicity and radicality, the external approach could be a good option.