Background: Tricuspid atresia (TA) is the second most common form of functionally univentricular heart. For patients with TA and normally related great arteries (Type I), left ventricular outflow tract obstruction (LVOTO) is rare.
Methods: From the Congenital Heart Surgeons' Society multi-institutional cohort of 445 patients with Type I TA enrolled from 1999 to 2024 from 42 sites, 14 infants (3%) had interventions for associated LVOTO, either at presentation or after their first TA-related intervention.
Results: Of seven infants initially undergoing Norwood/Damus-Kaye-Stansel (DKS), six survived to Stage II, of whom five survived with one developing pulmonary hypertension and four achieving Fontan. An additional seven infants who were first managed with pulmonary artery band placement subsequently had bidirectional superior cavopulmonary anastomosis (BCPA) and a DKS procedure; there were six survivors, all achieving Fontan. All ten survivors who underwent the Fontan procedure had normal left ventricular and mitral valve function at the latest follow-up. The overall Kaplan-Meier survival estimate at 20 years for these 14 patients was 79% (70% CI, 66%-88%), and the median follow-up was 8.3 years (0.24-21.5).
Conclusions: While infants with TA and transposition of the great arteries are more likely to have LVOTO, this can also occur in the setting of normally related great arteries. Infants with Type I TA and LVOTO can be managed in the neonatal period with the Norwood procedure ensuring complete arch relief with acceptable outcomes. If LVOTO becomes evident after initial pulmonary artery band placement, a subsequent DKS procedure facilitates satisfactory success to Fontan.
Keywords: Norwood procedure; cardiac anatomy/pathologic anatomy; functionally univentricular heart; tricuspid atresia.