Objective: No standard protocol is available for the management of children with Down's syndrome (DS) and a functional single ventricle. This review attempts to determine the outcomes of the single ventricular surgical palliation pathway in high-risk children with DS.

Methods: Several databases were searched using the following MeSH terms: 'Congenital heart disease', 'Atrioventricular septal defect', 'Balanced AVSD', 'Unbalanced AVSD', 'Down's syndrome', 'Univentricular repair', 'bidirectional Glenn procedure', and 'Fontan procedure'. A structured algorithm was used for the selection of studies for an in-depth analysis.

Results: There was no universal agreement on the best surgical approach for unbalanced atrioventricular septal defect in DS. The majority of paediatric cardiac surgeons did not recommend the complete Fontan procedure; conversely, the use of a Glenn shunt (superior cavopulmonary connection) was preferred.

Conclusions: Careful assessment of the suitability for Fontan surgery, including the absence of elevated pulmonary vascular resistance, pulmonary arterial anatomy, and function of the dominant ventricle, is mandatory. A staged surgical procedure ending with complete Fontan repair provides acceptable medium-term results.