Unlocking the Non-invasive Assessment of Conduit and Reservoir Function in the Aorta

Aortic surgeries in congenital conditions, such as hypoplastic left heart syndrome (HLHS), aim to restore and maintain the conduit and reservoir functions of the aorta. We proposed a method to assess these two functions based on 4D flow MRI, and we applied it to study the aorta in pre-Fontan HLHS. Ten pre-Fontan HLHS patients and six age-matched controls were studied to derive the advective pressure difference and viscous dissipation for conduit function, and pulse wave velocity and elastic modulus for reservoir function. The reconstructed neo-aorta in HLHS subjects achieved a good conduit function at a cost of an impaired reservoir function (69.7% increase of elastic modulus). The native descending HLHS aorta displayed enhanced reservoir (elastic modulus being 18.4% smaller) but impaired conduit function (three-fold increase in peak advection). A non-invasive and comprehensive assessment of aortic conduit and reservoir functions is feasible and has potentially clinical relevance in congenital vascular conditions.

Automated summary

This study proposed a method to assess the conduit and reservoir functions of the aorta in congenital vascular conditions and applied it to study the aorta in pre-Fontan hypoplastic left heart syndrome patients. The reconstructed neo-aorta in these patients showed good conduit function but impaired reservoir function, while the native descending HLHS aorta displayed enhanced reservoir function but impaired conduit function. This non-invasive and comprehensive assessment has potential clinical relevance in congenital vascular conditions.