The 2-Dimensional and 3-Dimensional Anatomy of the Adult Brachial Plexus Divisions and Cords.

Background: The objective of this work was to perform a critical review of the 2-dimensional and 3-dimensional anatomy of the adult brachial plexus divisions and cords. Methods: Twelve adult brachial plexuses from fresh cadavers were dissected. All were male and aged between 30 and 50 years. Only corpses without brachial plexus injuries were selected. The purpose of the dissections was to identify the origin of the anterior and posterior divisions of the adult brachial plexus in their respective trunks, as well as the positioning of the posterior, lateral, and medial cords. Results: The posterior division of all trunks had a cranial and dorsal origin, while the anterior division of all trunks had a caudal and ventral origin. The posterior cord was the most cranial of all, the lateral cord was central, and the medial cord was the most caudal of all cords. The posterior division of the superior trunk was always between the suprascapular nerve and the anterior division. Conclusions: Brachial plexus diagrams in most textbooks and papers are different from what was found in our dissections. Contrary to the known diagram, the posterior divisions always had a cranial origin in the superior, middle, and inferior trunks.

An anatomically detailed arterial network model for one-dimensional computational hemodynamics.

Simulation platforms are increasingly becoming complementary tools for cutting-edge cardiovascular research. The interplay among structural properties of the arterial wall, morphometry, anatomy, wave propagation phenomena, and ultimately, cardiovascular diseases continues to be poorly understood. Accurate models are powerful tools to shed light on these open problems. We developed an anatomically detailed computational model of the arterial vasculature to conduct 1-D blood flow simulations to serve as simulation infrastructure to aid cardiovascular research. An average arterial vasculature of a man was outlined in 3-D space to serve as geometrical substrate for the mathematical model. The architecture of this model comprises almost every arterial vessel acknowledged in the medical/anatomical literature, with a resolution down to the luminal area of perforator arteries. Over 2000 arterial vessels compose the model. Anatomical, physiological, and mechanical considerations were employed for the set up of model parameters and to determine criteria for blood flow distribution. Computational fluid dynamics was used to simulate blood flow and wave propagation phenomena in such arterial network. A sensitivity analysis was developed to unveil the contributions of model parameters to the conformation of the pressure waveforms. In addition, parameters were modified to target model to a patient-specific scenario. On the light of the knowledge domain, we conclude that the present model features excellent descriptive and predictive capabilities in both patient-generic and patient-specific cases, presenting a new step toward integrating an unprecedented anatomical description, morphometric, and simulations data to help in understanding complex arterial blood flow phenomena and related cardiovascular diseases.

Blood flow distribution in an anatomically detailed arterial network model: criteria and algorithms.

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.