A surgical procedure for the implantation of a coronary stent in a specific patient resulted in thrombus formation in the aortic root. The stent was placed aiming to prevent stenosis in the artery, but it was misplaced, and led to the appearance of a thrombus. This work’s primary goal is to analyze changes in blood flow conditions due to the appearance and potential growth of the thrombus in the direction of the stent and the coronary artery. In other words, numeric simulations of blood flow in the aortic root region were executed aiming to identify if the presence of the thrombus would impact in hemodynamic conditions so that it could develop risks to the health and well-being of the patient. A first test concluded that 260 thousand mesh elements is a good reference value for numerical simulations in this specific geometry. Secondly, the Carreau viscosity model, which is non Newtonian, was compared with a model of constant viscosity, and it was shown that the Newtonian model was a sufficiently adequate fit to the expected results within the coronary arteries. Finally, for the case in which the primary dimension of the thrombus was elongated enough that it reached the coronary wall, local values in pressure drops were around 4 percent, and the obstruction caused by the thrombus amounted to 26 percent of the area section of the coronary artery. Medical references indicate that, in order for the patient to face significant health risks, pressure drops should not be less than 20 percent, and the obstruction of the coronary artery section area would be around 50 percent, numbers much larger than the results produced.