Computationally guided in-vitro vascular growth model reveals causal link between flow oscillations and disorganized neotissue

AbstractDisturbed shear stress is thought to be the driving factor of neointimal hyperplasia in blood vessels and grafts, for example in hemodialysis conduits. Despite the common occurrence of neointimal hyperplasia, however, the mechanistic role of shear stress is unclear. This is especially problematic in the context ofin situscaffold-guided vascular regeneration, a process strongly driven by the scaffold mechanical environment. To address this issue, we herein introduce an integrated numerical-experimental approach to reconstruct the graft-host response and interrogate the mechanoregulation in dialysis grafts. Starting from patient data, we numerically analyze the biomechanics at the vein-graft anastomosis of a hemodialysis conduit. Using this biomechanical data, we show in anin vitrovascular growth model that oscillatory shear stress, in the presence of cyclic strain, favors neotissue development by reducing the secretion of remodeling markers by vascular cells and promoting the formation of a dense and disorganized collagen network. These findings identify scaffold-based shielding of cells from oscillatory shear stress as a potential handle to inhibit neointimal hyperplasia in grafts.</jats:p

Recovering Surfaces from the Restoring Force

Abstract. We present a new theoretical method and experimental re-sults for direct recovery of the curvatures, the principal curvature direc-tions, and the surface itself by explicit integration of the Gauss map. The method does not rely on polygonal approximations, smoothing of the data, or model tting. It is based on the observation that one can recover the surface restoring force from the Gauss map, and (i) applies to orientable surfaces of arbitrary topology (not necessarily closed); (ii) uses only rst order linear dierential equations; (iii) avoids the use of unstable computations; (iv) provides tools for ltering noise from the sampled data. The method can be used for stable extraction of surfaces and surface shape invariants, in particular, in applications requiring ac-curate quantitative measurements.

Data underlying the publication: Computationally guided in-vitro vascular growth model reveals causal link between flow oscillations and disorganized neotissue

This repository contains the data and scripts required to reproduce the subfigures of figure 2 of: van Haaften et al 2021 "Computationally guided in-vitro vascular growth model reveals causal link between flow oscillations and disorganized neotissue" related to the computational simulations. More specifically, this repository contains:1) Datasets to visualize the time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI) and the strain (ε) in graft at the venous anastomosis in Paraview. 2) Scripts and data to produce histograms of the time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI) and the strain (ε) in the graft at the venous anastomosis in MATLA