Cohort-based multiscale analysis of hemodynamic-driven growth and remodeling of the embryonic pharyngeal arch arteries.

Growth and remodeling of the primitive pharyngeal arch artery (PAA) network into the extracardiac great vessels is poorly understood but a major source of clinically serious malformations. Undisrupted blood flow is required for normal PAA development, yet specific relationships between hemodynamics and remodeling remain largely unknown. Meeting this challenge is hindered by the common reductionist analysis of morphology to single idealized models, where in fact structural morphology varies substantially. Quantitative technical tools that allow tracking of morphological and hemodynamic changes in a population-based setting are essential to advancing our understanding of morphogenesis. Here, we have developed a methodological pipeline from high-resolution nano-computed tomography imaging and live-imaging flow measurements to multiscale pulsatile computational models. We combine experimental-based computational models of multiple PAAs to quantify hemodynamic forces in the rapidly morphing Hamburger Hamilton (HH) stage HH18, HH24 and HH26 embryos. We identify local morphological variation along the PAAs and their association with specific hemodynamic changes. Population-level mechano-morphogenic variability analysis is a powerful strategy for identifying stage-specific regions of well and poorly tolerated morphological and/or hemodynamic variation that may protect or initiate cardiovascular malformations.