LAUSR

OBJECTIVES Management of "failing" and "failed" Fontan circulation particularly the indications, timing, and type of re-intervention currently remain nebulous. Factors contributing to pathogenesis and mortality following Fontan procedure differ between children and adults. METHODS Since organ systems in individual patients are affected differently, we searched the extant literature for a "failing" and "failed" Fontan reviewing the clinical phenotypes, diagnostic modalities, pharmacological, non-pharmacological, and surgical techniques employed, and their outcomes. RESULTS A total of 410 investigations were synthesized. Although proper candidate selection, thoughtful technical modifications, timely deployment of mechanical support devices, tissue engineered conduits, and Fontan takedown have decreased the perioperative mortality from 9-15% and 1-3% percent in recent series, pernicious changes in organ function are causing long-term patient attrition. In the setting of a failed Fontan circulation, literature documents three surgical options: Fontan revision, Fontan conversion or cardiac transplantation. The reported morbidity of 25% and mortality of 8-10% among Fontan conversion continue to improve in select institutions.While operative mortality following cardiac transplantation for Fontan failure is 30% higher than for other congenital heart diseases, there is no difference in long-term survival with actuarial 10 years survival of around 54%. Mechanical circulatory assistance, stem cells and tissue engineered-Fontan conduit for destination therapy or as a bridge to transplantation are in infancy for failing Fontan circulation. CONCLUSIONS An individualized management strategy according to clinical phenotypes may delay the organ damage in patients with a failing Fontan circulation. At present, cardiac transplantation remains the last stage of palliation with gradually improving outcomes.