Abstract: AIM: To evaluate the therapeutic efficacy and safety of transcatheter closure of patent foramen ovale(PFO) with cryptogenic stroke.METHODS: Infarcted lesions were confirmed by CT or MRI in 26 patients with PFO with ischemic stroke(aged 35±12 years,range 7-52 years).Other identifiable causes such as aorta and cerebral vascular disease or left ventricular system disease were excluded.TCD displayed right to left shunting through PFO during Valsalva and TTE/TEE confirmed atrial septum aneurysm(ASA).All patients underwent transcatheter closure of patent foramen ovale.RESULTS: TEE showed that the average diameter of PFO in the 26 patients was(3±1) mm(range: 1-5 mm) and five cases were defined as PFO with ASA.TCD and bubble test assessed the degree of shunting,including six cases of grade 1,nine cases of grade 2,and 11 cases of grade 3 or higher.Twenty-four cases were successfully occluded,with the success rate of 92.3%.The size of the occluder was from 18-35 mm,including six cases of 18 mm,seven cases of 25 mm,eight cases of 30 mm and three cases of 35 mm.The main cause for the two unsuccessful cases was the failure of the wire to go through the atrial septum.No displacement of occluder and no residual shunt were observed by TTE during the 6-month to 1-year follow-up.No recurrence of ischemic cerebral infarction occurred.CONCLUSION: Transcatheter interventional occlusion of PFO is safe and effective in reducing recurrence of ischemic stroke.