The Fontan palliation is associated with numerous complications during long-term. The Fontan conversion operation has been advocated as an option to avoid some of these problems by converting classical Fontan types to modern forms of the circulation. Early mortality of Fontan conversion, however, remains unclear as available reports include limited numbers of patients and the results are heterogeneous.

We reviewed all original articles from 1994 to 2016 reporting Fontan conversion operations. Reports were analysed with specific reference to patient demographics, patient number, concomitant arrhythmia surgery, pacemaker implantation and early mortality.

Overall, 37 Fontan conversion studies with a total of 1182 patients were analysed, including 35 single-centre studies and 2 registers. In the 35 single-centre studies the average age at the time of conversion was 21.6 years (range 10.2–30.9 years). Concomitant arrhythmia operation was performed in 71.6% of patients and concomitant pacemaker implantation procedure was performed in 59.3% of patients. Early mortality varied greatly between publications ranging from 0 to 21%. Based on a random and a fixed effect model mean mortality was 5.3% and 6.2%, respectively. Lower mortality was observed in series including younger patients at the time of conversion (average age < 20 years, 4.6%) and in the highest volume centre (1.4%).

Fontan conversion carries a substantial mortality risk. However, results vary between centres. Overall, the combination with arrhythmia surgery seems to be associated with lower early mortality especially when patients are referred at an earlier age and are treated at highly experienced centres.