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The goal of this work is to assess the impact of vascular anatomy definition degree in the predictions of blood flow models of the arterial network. To this end, results obtained with an anatomically detailed network containing over 2000 vessels are systematically compared with those obtained with an anatomically simplified network containing the main 86 vessels, the latter being a truncated version of the former one. The comparison is performed quantitatively and qualitatively in terms of pressure and flow rate waveforms, wave intensity analysis and impedance analysis. Comparisons are performed under physiological conditions and for the case of common carotid artery occlusion. Mechanisms of blood flow delivery to the brain, as well as different blood flow steal phenomena, are unveiled in light of model predictions. Results show that detailed and simplified models are in reasonable agreement regarding the hemodynamics in larger vessels and in healthy scenarios. The anatomically detailed arterial network features improved predictive capabilities at peripheral vessels. Moreover, discrepancies between models are substantially accentuated in the case of anatomical variations or abnormal hemodynamic conditions. We conclude that physiologically meaningful agreement between models is obtained for normal hemodynamic conditions. This agreement rapidly deteriorates for abnormal blood flow conditions such as those caused by total arterial occlusion. Differences are even larger when modifications of the vascular anatomy are considered. This rational comparison allows us to gain insight into the need for anatomically detailed arterial networks when addressing complex hemodynamic interactions.

Development of blood flow distribution criteria is a mandatory step toward developing computational models and numerical simulations of the systemic circulation. In the present work, we (i) present a systematic approach based on anatomical and physiological considerations to distribute the blood flow in a 1D anatomically detailed model of the arterial network and (ii) develop a numerical procedure to calibrate resistive parameters in terminal models in order to effectively satisfy such flow distribution. For the first goal, we merge data collected from the specialized medical literature with anatomical concepts such as vascular territories to determine blood flow supply to specific (encephalon, kidneys, etc.) and distributed (muscles, skin, etc.) organs. Overall, 28 entities representing the main specific organs are accounted for in the detailed description of the arterial topology that we use as model substrate. In turn, 116 vascular territories are considered as the basic blocks that compose the distributed organs throughout the whole body. For the second goal, Windkessel models are used to represent the peripheral beds, and the values of the resistive parameters are computed applying a Newton method to a parameter identification problem to guarantee the supply of the correct flow fraction to each terminal location according to the given criteria. Finally, it is shown that, by means of the criteria developed, and for a rather standard set of model parameters, the model predicts physiologically realistic pressure and flow waveforms.