Experimental Assessment of the Impact of Asymptomatic Gas Emboli on the Vessel Wall

Quantitative evaluation of shear stress in the vessel wall due to the presence of asymptomatic gas emboli is lacking. The goal of this work was to assess the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis through a custom-built cardiovascular flow simulator. Gas bubbles were created by forced air from a syringe pump. The influences of embolism injection rate, pulse rate, and time-averaged flow rate on the wall mean shear stress were investigated at resting and elevated heart rate conditions. The recorded pressure and volumetric flow rate from 24 experimental settings with four repetitions each were used to calculate the mean wall shear stress (MWSS). A directly inverse relationship between gas embolus rate and MWSS in the vessel, particularly at low vascular flow and diminished pulse rates was subsequently found. This study established a positive correlation between gas bubbles in the bloodstream and diminished MWSS, which implied a potential onset of atherosclerosis.