Abstract Background The efficient closure of patent foramen ovale (PFO) with short canal length and large width, usually associated with atrial septal aneurysm (ASA), remains challenging. These cases frequently require the use of larger PFO devices to avoid the risk of device embolism at the cost of a higher rate of residual shunting, mostly due to interdisk spacing. The use of atrial septal defect (ASD) prosthesis could be useful in these patients. Purpose To describe feasibility and early outcomes of the use of ASD device for percutaneous closure of widely open PFO representing an "ASD-like anatomy". Methods Since January 2022 in a high volume French university center, we started to use ASD device for percutaneous closure of selected cases of PFO with complex anatomy as mainly defined by a sheathed width of PFO ≥ 5 mm and sheathed canal length ≤ 10 mm (Figure 1) facing major per-operative residual shunt with PFO prostheses in some patients. In addition to the descriptive results, we compared this ASD device subgroup with a cohort of patients with similar anatomy but previously treated in our center with PFO device. All available transesophageal echocardiography (TEE) examinations were reviewed. The main objective was to describe the feasibility of the procedure (success and safety), the secondary endpoint was immediate post-procedural moderate to severe residual right-to-left shunt (RLS), defined as ≥ 10 bubbles in the left atrium within 3 cardiac cycles after transfemoral agitated saline injection. Results A total of 65 patients was treated with ASD devices, procedural success was achieved in all patients with a low rate (4,2%) of intrahospital complications (two supraventricular arrythmia, one anaphylactic shock and one minor laryngeal injury) and without device embolism. As compared with a cohort of 127 patients of similar anatomy treated with PFO device, patients in the ASD device group had more complex characteristics especially higher mean sheathed PFO width and shorter mean sheathed PFO canal length. Immediate post-procedural residual moderate to severe RLS did not differ significatively between groups (Table 1). No or minimal shunting was observed in 91% and 92% of cases (p=NS) but the three patients with severe RLS were all in the PFO device group. Conclusion Percutaneous closure of "ASD-like" PFO with ASD prostheses is feasible and safe. Larger studies and longer follow-ups are now required to confirm the expected improved sealing effect with this strategy.