JTCVS Open. 2026 May 4;32:101833. doi: 10.1016/j.xjon.2026.101833. eCollection 2026 Aug.
ABSTRACT
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.
PMID:42604323 | PMC:PMC13477081 | DOI:10.1016/j.xjon.2026.101833