Hypoplastic left heart syndrome (HLHS) becomes of age: Assessing the young adult with HLHS including the neoaorta/aortic arch

Hypoplastic left heart syndrome (HLHS) is one of the most complex congenital heart defects (CHD), characterized by a hypoplastic left ventricle (LV), dominant right ventricle (RV) and small left-sided heart structures. The introduction of the Norwood operation has significantly improved outcomes, with 5-year survival reported up to 65 %. Despite these advances, post-operative morbidity and mortality remain high, and the long-term complications in adult survivors represent a challenge. The number of HLHS patients with Fontan circulation is expected to double in the next 20 years, leading to a growing population requiring specialized care from adult congenital heart disease (ACHD) teams.

This article reviews current management strategies for HLHS, outlines potential long-term complications, and highlights existing knowledge gaps. Specific considerations in this population include the assessment of the neo-aorta and aortic arch, and systemic RV dysfunction in the setting of a Fontan circulation. The proposed surveillance strategy emphasizes the need for vigilant monitoring and timely intervention to treat the complications unique to this population, ensuring better outcomes for HLHS patients reaching adulthood.