Remodeling of pulsatile flow networks

Existing models of adaptation in biological flow networks consider their constituent vessels (e.g. veins and arteries) to be rigid at short time-scales, thus predicting a non physiological response when the drive (e.g the heart) is dynamic. Here we use a modified adaptation model that incorporates pulsatile driving and the transient spatio-temporal dynamics of elastic vessels, and show that it fundamentally alters the expected long-time structure of branched flow networks. We show that pulsatility stabilizes loops and prevents vascular shunting for a much broader range of metabolic cost functions than predicted by existing theories, and we investigate under what conditions loops proximal to the heart are preferred compared to more distal ones. Our work points to the need for a more realistic treatment of adaptation in complex elastic flow networks, especially those driven by a pulsatile source, and provides possible insights into pathologies that emerge when such pulsatility is disrupted in human beings.