To evaluate the safety and effectiveness of the SnowyTM PFO closure system in plugging patent foramen ovale
Age: 18 to 65 years old, regardless of gender
Transthoracic echocardiographic contrast echocardiography (cTTE) confirmed the presence of PFO and at least moderate (see above definition) RLS (in Valsalva active/resting state)
Existence of at least one of the following conditions： 1) Unexplained stroke or TIA 2) intractable or chronic migraine
The subjects are informed of the nature of the study and agreed to all requirements for participation in the study, signed the informed consent form, and agree to complete the follow-up and follow-up examination
Patients have definite causes of stroke unrelated to the PFO
RLS caused by other causes, such as atrial septal defect or pulmonary arteriovenous shunt
Atrial fibrillation or atrial flutter
Mitral and aortic stenosis or severe regurgitation