The effect of beta-blockers on hemodynamic parameters in patient-specific blood flow simulations of type-B aortic dissection: a virtual study

Abstract

Aortic dissection (AD) is one of the fatal and complex conditions. Since there is a lack of a specific treatment guideline for type-B AD, a better understanding of patient-specific hemodynamics and therapy outcomes can potentially control the progression of the disease and aid in the clinical decision-making process. In this work, a patient-specific geometry of type-B AD is reconstructed from computed tomography images, and a numerical simulation using personalised computational fluid dynamics (CFD) with three-element Windkessel model boundary condition at each outlet is implemented. According to the physiological response of beta-blockers to the reduction of left ventricular contractions, three case studies with different heart rates are created. Several hemodynamic features, including time-averaged wall shear stress (TAWSS), highly oscillatory, low magnitude shear (HOLMES), and flow pattern are investigated and compared between each case. Results show that decreasing TAWSS, which is caused by the reduction of the velocity gradient, prevents vessel wall at entry tear from rupture. Additionally, with the increase in HOLMES value at distal false lumen, calcification and plaque formation in the moderate and regular-heart rate cases are successfully controlled. This work demonstrates how CFD methods with non-invasive hemodynamic metrics can be developed to predict the hemodynamic changes before medication or other invasive operations. These consequences can be a powerful framework for clinicians and surgical communities to improve their diagnostic and pre-procedural planning.

Synthetic 18F-FDG PET Image Generation Using a Combination of Biomathematical Modeling and Machine Learning

“…The summary of the procedure for calculating intravascular blood flow with adaptable vessels and non-continuous blood behavior is as below: Consider initial guesses for parameters of the model (i.e., intravascular blood pressure (IBP), blood viscosity, hematocrit, and vessel diameter); Calculate IBP in each vascular node iteratively through an algorithm called successive over-relaxation (SOR); Calculate hematocrit and total adaptive stimuli (i.e., wall shear stress stimulus, pressure stimulus of capillaries, and metabolic stimulus); Update capillary diameter based on a new value calculated in step 3; Calculate laminar intravascular blood flow rate according to Poiseuille’s law due to the low Reynolds number [ 29 , 30 ]; Calculate the velocity in each capillary; Find hematocrit at the vessel bifurcations; Update the apparent viscosity according to the capillary diameter and hematocrit; Ensure accurate solving by calculating the maximum relative error of IBP and vessel diameter using max , in which can be each of IBP or vessel diameter and and correspond to the current and previous time steps, respectively; If the maximum relative error is greater than the defined threshold (10 −4 ), the iterative procedure should be back to step 2, and the new solutions of parameters should be substituted for the previous quantities. Otherwise, the procedure is considered to be finished, and the IBP values can be used in the next stage of the simulation.…”

“…Calculate laminar intravascular blood flow rate according to Poiseuille’s law due to the low Reynolds number [ 29 , 30 ];…”

A Systematic Review and Meta‐Analysis of the Relationship between Receiving the Flu Vaccine with Acute Cerebrovascular Accident and Its Hospitalization in the Elderly

“…William Osler was one of the first to describe the role of infectious agents in the pathogenesis of atherosclerosis [ 52 ]. In the late 1970s, scientists began to study the role of herpes, chlamydia, or pneumonia and later Helicobacter pylori, Mycoplasma pneumonia, and Enterovirus into animal models and observed that these factors were associated with atherosclerosis [ 49 , 50 , 53 – 60 ]. These efforts coincided with the emergence of new evidence of atherosclerosis as an inflammatory disease [ 61 ].…”

Aortic arch surgery for type B aortic dissection: How far should we go? The value of a hybrid approach

“…Besides, a more personalized approach based on patient‐specific modeling may add a different dimension. 58 , 59 , 60 , 61 , 62 The ability to model and simulate the effect of device implantation with reference to key elements and discuss the findings during a MDT meeting would allow visualization of the intended therapeutic approach and help with preoperative planning in relation to treatment optimization and outcome prediction. 63 , 64 , 65 , 66 , 67 The mapping of certain patterns of flow behavior may also help identify potential problems during patients' follow‐up and become an aid for decision‐making should further treatment be required.…”