ObjectiveTo assess the feasibility and safety of percutaneous transcatheter closure of atrial septal defect (ASD) guided by transthoracic echocardiography (TTE) in outpatients.MethodsFrom December 2016 to June 2018, 50 simple ASD patients underwent TTE-guided transcatheter closure in the outpatient operating room of our hospital (a TTE group) including 22 males and 28 females at the age of 16-48 (27.40±6.95) years. Fifty patients with simple ASD treated with the guidance of conventional fluoroscopy during the same period were treated as a control group, including 22 males and 28 females at the age of 15-48 (28.58±6.96) years. Both groups were re-examined by TTE during follow-up at 1 month, 3 months, 6 months and 1 year.ResultsThe mean age, body weight, the size of ASD and occluder and success rate had no statistical difference between the two groups (P>0.05). Compared with the control group, the TTE group had significantly lower mean operation time (P<0.01) and less cost (P<0.01) since patients need not to be hospitalized. No related complications were found in the TTE group during follow-up.ConclusionPercutaneous transcatheter closure of ASD guided by TTE appears safe and effective for outpatients, and can significantly reduce the cost.