Hemodynamic parameters and vessel tortuosity: an investigation with a mesenterial vascular network

Roberto Annunziata,Bettina Reglin,Emanuele Trucco,Axel R Pries

doi:10.35119/maio.v1i4.46

Abstract

Purpose: The effect of hemodynamic parameters on vessel tortuosity remains un-clear. Here we investigate the correlation of tortuosity with a set of hemodynamicparameters in a mesenterial vascular network.Methods: A mesenterial vascular network of 389 vessels (131 arteries, 132 veins, and 126 capillaries) was imaged. Eleven hemodynamic parameters were measured (pressure, wall shear stress, diameter, blood velocity and flow, viscosity, haematocrit, partial oxygen saturation, oxygen saturation, wall thickness, and local vessel density). Tortuosity was assessed quantitatively with a validated algorithm and correlation computed with subsets of hemodynamic parameters selected by a lasso regressor.Results: Results suggest that tortuosity is related to pressure, wall shear stress, diameter, blood velocity, viscosity, partial but not full oxygen saturation, and wall thickness for the arteries; diameter, blood flow, hematocrit, and density for the veins; and viscosity (but not hematocrit), partial and full oxygen saturation, and density for the capillaries. The combination of hemodynamic parameters correlating best with tortuosity is the set of all parameters except density (r = 0.64, p < 0.01), using as tortuosity definition the set of tortuosity features (geometric measures) correlating best with a single hemodynamic factor for the arteries.Conclusion: This pilot suggests two general conclusions. First, the quantitative definition of tortuosity (i.e., the set of geometric features adopted) should be tuned to the specific data and problem considered. Second, tortuosity is caused by a combination of hemodynamic factors, not a single one.

Highlights

Vessel tortuosity is a qualitative clinical index associated with the degree of bendiness of a vascular network or segments thereof
These results suggest that tortuosity is related to: pressure, wall shear stress, diameter, blood velocity, viscosity, partial but not full oxygen saturation, and wall thickness for the arteries; diameter, blood flow, hematocrit, and density for the veins; viscosity, partial and full oxygen saturation, and density for the capillaries
The motivation behind Experiment ( ) is that correlations between each tortuosity feature and each hemodynamic factor are typically low (i.e., < . ), suggesting that tortuosity is caused by a combination of hemodynamic factors, not a single one

Summary

Introduction

Vessel tortuosity is a qualitative clinical index associated with the degree of bendiness of a vascular network or segments thereof. Changes in retinal vessel tortuosity have been associated with several conditions, both systemic and eye-specific, and several computational models of tortuosity developed. – Kylstra et al modeled the deformation of a blood vessel experimentally using a latex tube resting on a horizontal surface. They measured shape changes of the tube following variations of the pressure inside the tube. They observed that diameter changes dominate over tortuosity ones as long as the pressure remains below a certain level; beyond this level, buckling occurs and tortuosity increases more rapidly than diameter

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Results

Discussion

Conclusion