Abstract: Objective  To explore the efficacy and safety of standalone left atrial appendage closure under total thoracoscopy on stroke prevention in patients with non-valvular atrial fibrillation at high bleeding risks. Methods  A total of 66 patients with non-valvular atrial fibrillation at high risk of bleeding were enrolled, including 7 patients with paroxysmal atrial fibrillation, and 59 patients with persistent or permanent atrial fibrillation.  The efficacy of standalone left atrial appendage closure under total thoracoscopy was evaluated in patients with non-valvular atrial fibrillation at high bleeding risks. Furthermore, adverse events associated with operation were recorded to demonstrate the protective effect on stroke during follow-up. Results  The left atrial appendage were successfully closed in all the participants, with an average duration of (2.22±0.97) hours. About 90% of patients showed residual roots no more than 10 mm after surgery, and all patients had no internal leakage or displacement of the auricle clip. No significant differences in surgery time, postoperative drainage, and surgical success rate were observed between elderly patients and comparators. One should be noted that elderly patients showed a longer postoperative extubation time compared to other age groups, while all patients were successfully extubated. No unplanned secondary surgeries were performed, accompanied with no perioperative deaths based on safety parameters. Bleeding event was reported in one patient, which was attributed to the pull of the auricle tip during surgery. Bleeding event was efficiently ceased after releasing the auricle clip. An average follow-up lasted (17.3±0.7) months. Two patients developed new onset of ischemic stroke, with one presenting with new cerebral infarction and the other presenting with transient ischemic attack. Conclusions  The standalone left atrial appendage closure under total thoracoscopy serves as a novel treatment option for stroke prevention in patients with non-valvular atrial fibrillation at high bleeding risks. This procedure is characterized with high success rate, low incidence of leaks and fewer complications. Furthermore, similar efficacy and safety were observed in elderly patients undergoing surgery compared to the control group matched with other factors.

Key words: total thoracoscopy, standalone left atrial appendage closure, non-valvular atrial fibrillation, stroke prevention, high bleeding risk