He'll likely be on blood thinners for a few months, but I would think he can resume normal activity after that as long as no arrhythmia or idiosyncratic blood flow is detected. The main complication of PFO and the surgery to treat it is the potential for clots. Blood likes laminar flow, and it's made for it. When the flow of blood is interrupted or changed by an inserted catheter, an arrhythmia, etc, platelets basically start bumping into each other and forming agglomerations, ie clots. Platelets are designed to clot under certain conditions and non-laminar blood flow creates those conditions where they shouldn't be, hence the necessity for anti-coagulants for people with PFO, atrial fibrilation, etc.