The bidirectional Glenn's shunt (BDG) is the first step in the systematic, staged approach to a Fontan operation for patients with univentricular hearts. For the BDG to function well, the flow of blood through the pulmonary circulation must be free from significant impediments so that systemic venous pressure does not reach physiologically unacceptable levels. High systemic venous pressures are associated with high morbidity because of persistent bilateral pleural effusions and pericardial effusions, low oxygenation, increased plasma transfusion requirements, albumin infusions to maintain plasma protein levels, and prolonged ICU stay. We present a case of BDG complicated by prolonged pleural effusions in the immediate postoperative period, which was managed successfully using a percutaneous catheter-based approach, and thereby avoiding the complications of a major redo cardiac surgery.