The Fontan operation has been a major forward step in the management of patients born with a functional univentricular heart.There are a number of potential advantages of extracardiac conduit cavopulmonary anastomosis , including the ability to perform the operation with no aortic cross-clamping and with minimal duration of extra-corporeal circulation. In many patients, it may be possible to perform the procedure without cardiopulmonary bypass altogether. The alternative method of cross-clamping the inferior vena cava is safe. A certain preparation may be needed, such as preservation of the Azygos venous system at the time of the bidirectional Glenn. Proper hemo-dynamic management during the operation is another factor for promoting the result .The hemodynamics and oxygen saturation must be monitored closely.When there is any question about safety, CPB should be instituted immediately. A temporary bypass between the IVC and the right atrium could be done to decompress the IVC.