Effective treatment for many congenital heart diseases diagnosed before birth has become available since the last three decades. Continuous improvements in surgical knowledge and techniques have allowed patients born with severe heart defects to survive through adulthood. However, palliative surgery often implies profound modifications of classical circulatory physiology, which must be taken into account particularly when general anesthesia is needed for major noncardiac surgery. Among the palliative surgeries, Fontan repair is an intervention aiming at excluding the right heart chambers with a total cavopulmonary conduit, which directs blood flow from both inferior and superior vena cavae directly to the right pulmonary artery. In such condition, patients are very sensitive to both preload reduction and pulmonary vascular resistances increase, so that a careful monitoring during anesthesia is required. Unfortunately, standard monitoring with a pulmonary artery catheter is not possible because of altered anatomy of right sections. In this case scenario, the authors report the perioperative management of a young woman who underwent major gynecologic surgery, who was managed using a transpulmonary thermodilution technique that was deemed more accurate than noncalibrated pulse-contour method and also able to provide more information regarding preload status. The authors adopted an integrated approach merging together hemodynamic and functional data (ScvO2 and venoarterial CO2 difference) to assess the appropriateness of hemodynamic management. The authors describe also pathophysiologic changes during such condition and also potential drawbacks of chosen technique.