InterPore2026

Can morphological adaptations of microvascular networks minimize anomalous transport?

21 May 2026, 10:05

1h 30m

Poster Presentation (MS09) Pore-Scale Physics and Modeling Poster

Speaker

George Atkinson (Université de Rennes)

Description

Anomalous transport in the microvasculature is increasingly recognized as a major contributor to tissue hypoperfusion. Perfusion studies often assume that metabolite delivery scales directly with blood flow volume, but this assumption neglects cases where blood may become metabolite-depleted before reaching target tissue. As a result, regions can receive seemingly normal levels of blood flow yet still suffer local metabolic deficits due to prolonged vascular travel times (Jespersen et al., 2012). For healthy vasculature, the impact of these long travel times is relatively muted. For example, models of travel time in healthy brains predict that only a small fraction of vessels (~1%) experience excessive travel times (Goirand et al., 2021). However, under pathological conditions, the same network model shows that even moderate reductions in blood flow can lead to a marked increase in the number of vessels experiencing long travel times (Goirand et al., 2021). Consequently, regions of the tissue supplied by the abnormal microvasculature may become metabolically depleted if enough flow pathways exceed a critical travel time threshold.

This raises a central question: can the microvascular network structurally adapt to limit the occurrence of long travel times? Specifically, can morphological changes to vessel diameters optimize flow distribution to reduce the number of slow, inefficient pathways?

The primary goal of this study is to determine whether morphological adaptations in microvascular networks can reduce the incidence of abnormally long travel times. Given the sensitivity of metabolite delivery to flow heterogeneity, we investigate whether adjustments to vessel diameters can promote more uniform and efficient travel times across the network. We frame this as a flow optimization problem. While classical approaches typically minimize energy dissipation or hydraulic resistance (Durand et al., 2004; Ghosh et al., 2008), models that target travel time optimization show that results depend strongly on the network’s constraints and the specific cost function used (Kirkegaard et al., 2020). For instance, minimizing travel time between a single source and sink can lead to vascular shunting, where flow is overly concentrated along the shortest path, depriving other regions and increasing travel times elsewhere in the network (Kirkegaard et al., 2020).

Our approach differs by focusing on the distribution of travel times, where travel time refers to the full path through the network, and transit time refers to flow through a single vessel. Since long travel times are primarily driven by a heavy-tailed distribution of transit times (Goirand et al., 2021), we minimize a cost function that penalizes long transit times throughout the network. In doing so, we aim to suppress the formation of long travel time pathways. We hypothesize that such morphological optimization can significantly reduce the tail of the travel time distribution, mitigating the emergence of anomalous transport patterns predicted by models without adaptation. This would suggest that the microvasculature has the capacity to structurally compensate for moderate perfusion deficits.