Explain Operation for Patients with High Pulmonary Vascular Resistance ?
When the pulmonary vascular resistance is very high (6-8 units/m2) closure of ASD is done either with fenestrated patch or flap valve patch pushed under limbus fossa ovalis.
In the flap valve technique if RA pressure goes very high it allows right to left shunt. If left atrial pressure is higher the flap valve closes against limbus fossa ovalis, which does not allow left to right shunt.