Decompression of superior vena cava during bidirectional Glenn shunt.

Patients undergoing bi-directional Glenn shunt for various congenital anomalies of the heart will have their superior vena cava (SVC) clamped during the procedure. The duration of the procedure is variable, ranging from five to 30 minutes. This can affect the cerebral perfusion due to raised venous pressure [Cerebral blood flow = Mean arterial pressure − (Intracranial pressure + Central venous pressure)]. Shunting away the SVC blood is a well known technique to counter this problem, but we describe two cases where a novel technique was successfully used to decompress the SVC.