Long-Term Outcomes of Fontan Patients With an Extracardiac Conduit: A Systematic Review and Meta-Analysis.

Background: Although Fontan palliation improves survival, it poses a large burden of lifelong morbidity. In extracardiac Fontan (ECF) patients, for example, conduit stenosis developing over time has been associated with Fontan failure and other adverse outcomes. This systematic review, for the first time, synthesized existing data on various long-term outcomes of ECF patients, including change in conduit and associated outcomes.

Methods: We searched the Medline, Embase, and Cochrane indexes from inception to 2023 and included studies reporting separate results for ECF patients with a follow-up time of at least 3 years. Full-text studies were assessed for risk of bias. We summarised information on the study, patient characteristics, and outcomes narratively and with the use of descriptive tables. Meta-analysis was performed to calculate pooled incidence rates of adverse events.

Results: We included 61 full-text studies, with most studies published after 2009 (77.0%) and using a retrospective cohort design (76.2%). The pooled incidence rates per 100 person-years were for arrhythmia 1.8 (95% confidence interval [CI] 1.3-2.6), thrombotic events 0.2 (95% CI 0.1-0.4), protein-losing enteropathy 0.7 (95% CI 0.5-1.0), conduit obstruction 0.7 (95% CI 0.3-1.5), reoperation 1.9 (95% CI 1.1-3.4), and late death 0.3 (95% CI 0.2-0.5). The ranges of hemodynamic and exercise parameters and findings from studies reporting changes in conduit size and liver disease were reported.

Conclusions: Although many studies have largely focused on long-term survival, several other adverse outcomes require further research to develop consensus-based definitions and approaches for evaluations, especially as the ECF population ages. (PROSPERO: CRD42024533080).