Surgical closure of patent foramen ovale (PFO) has been considered definitive and the gold standard for preventing recurrent paradoxical embolism. However, in contrast to transcatheter PFO closure, patients undergoing operation have not systematically been re-evaluated for residual shunting. This study aimed to assess the efficacy of surgical PFO closure during follow-up by transesophageal echocardiography (TEE).