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Contemporary outcomes of the Fontan operation: An Australian and New Zealand Fontan Registry study
Michael Daley1,2,3, Igor E Konstantinov1,2,3, Supreet Marathe4,5
1Department of Cardiothoracic Surgery, Royal Children's Hospital, Melbourne, Australia.
Insights
Extracardiac conduit size does not impact long-term Fontan procedure outcomes. However, lateral tunnel Fontan surgery and fenestration are linked to increased risks of supraventricular tachycardia and adverse events, respectively.
Area of Science:
- Pediatric Cardiology
- Congenital Heart Disease Surgery
- Cardiovascular Outcomes Research
Background:
- The Fontan procedure is a palliative surgery for single-ventricle congenital heart defects.
- Optimizing long-term outcomes after the Fontan procedure remains a critical challenge.
- Extracardiac conduits are commonly used, but their size impact is debated.
Purpose of the Study:
- To evaluate the influence of extracardiac conduit size on long-term outcomes following the Fontan procedure.
- To identify risk factors associated with adverse events after contemporary Fontan surgery.
Main Methods:
- A binational registry was utilized to collect data on patients undergoing the Fontan procedure.
- Composite outcomes included death, transplant, Fontan failure, SVT, thromboembolism, and pacemaker implantation.
- Multivariable and landmark analyses were performed to assess risk factors and long-term survival.
Main Results:
- Thirty-year transplant-free survival was 85%, with 75% freedom from Fontan failure.
- No significant difference in outcomes was observed between smaller (≤18 mm) and larger (≥20 mm) extracardiac conduits.
- Lateral tunnel, isomerism, and fenestration were associated with increased risk of sustained SVT and thromboembolic events.
Conclusions:
- Extracardiac conduit size does not appear to affect long-term clinical outcomes after the Fontan procedure.
- Patients with lateral tunnel Fontan surgery have a higher incidence of sustained SVT.
- Fontan fenestration may increase the incidence of late adverse events, necessitating careful consideration.
Objective:
We sought to review the impact of extracardiac conduit size and risk factors on the long-term outcomes of the contemporary Fontan procedure: lateral tunnel and extracardiac conduits.
Methods:
Data were collected from a binational registry. Composite outcome of late adverse events included death, transplant, Fontan failure, supraventricular tachycardia (SVT), thromboembolism, or pacemaker implantation.
Results:
Transplant-free survival and freedom from Fontan failure was 85% (95% CI, 80%-89%) and 75% (95% CI, 70%-80%) at 30 years, respectively. Extracardiac conduit sizes were available in 1075 patients, with 18 mm (n = 596) and 20 mm (n = 355) being the most common. There was no difference in transplant-free survival, Fontan failure, or late adverse events between patients who received extracardiac conduits with smaller or larger conduits (≤18 mm vs ≥20 mm, P = .41, P = .50, and P = .27, respectively). Only 8 patients (<1%) underwent conduit upsizing during follow-up, all concurrently with another intervention. Lateral tunnel, isomerism, and fenestration were associated with sustained SVT on multivariable analysis (hazard ratio [HR], 2.0, P = .002; HR, 2.4, P < .001; HR, 1.7, P = .013, respectively). Only Fontan fenestration and isomerism were associated with the incidence of thromboembolic events (n = 161) on multivariable analysis (HR, 1.5, P = .021 and HR, 1.4, P = .025, respectively). Landmark analysis was performed from 16 years of age in patients without Fontan failure (n = 813). Transplant-free survival and freedom from Fontan failure were 87% (95% CI, 81%-91%) and 80% (95% CI, 72%-85%) at 20 years from this time point, respectively.
Conclusions:
Despite recent suggestions, extracardiac conduit sizes do not appear to affect long-term clinical outcomes. Patients with lateral tunnel have a greater incidence of sustained SVT, and Fontan fenestration may increase incidence of late adverse events.