Enhanced External Counterpulsation Treatment Inhibitting Advanced Atherosclerotic Plaque Progression by Augmenting the Plaque Wall Stress： An in vivo FSI Study Based on Animal Experiment

Enhance external counterpulsation(EECP) procedure has exhibited itself to be an effective therapy for the management of ischemic cardiovascular diseases.However,considering that EECP significantly increases the acute diastolic pressure,whether it will intervene in the chronic progression of advanced plaque causing great concern in clinical application,but yet remains elusive presently.In the current paper,a fluid-structure interface(FSI) numerical model of artery with plaque component was developed based on in vivo hemodynamic measurement performed in a porcine model,to calculate the mechanical stresses of the plaque before and during EECP,and in turn to assess the potential effects of long-term EECP treatment on plaque progression.The results show that EECP augmented the wall shear stress(WSS) and plaque wall stress(PWS) over the cardiac cycles,as well as the spacial oscillatory of WSS(WSSG).During EECP treatment,the PWS level respectively raised 6.82% and 6.07% in two simulation cases.The current pilot study suggests that EECP treatment may play a positive effect on inhibiting the continued plaque progression by increasing the PWS level over the cardiac cycles.Meanwhile,the plaque morphology should be taken into consideration while making patient-specific plan for long-term EECP treatment in clinic.

Enhanced External Counterpulsation Inducing Arterial Hemodynamic Variations and Its Chronic Effect on Endothelial Function

To make clear the precise hemodynamic mechanism underlying the anti-atherogenesis benefit of enhanced external couterpulsation(EECP) treatment, and to investigate the proper role of some important hemodynamic factors during the atherosclerotic progress, a comprehensive study combining long-term animal experiment and numerical solving was conducted in this paper. An experimentally induced hypercholesterolemic porcine model was developed and the chronic EECP intervention was subjected. Basic hemodynamic measurement was performed in vivo, as well as the arterial endothelial samples were extracted for physiological examination. Meanwhile, a numerical model was introduced to solve the complex hemodynamic factors such as WSS and OSI. The results show that EECP treatment resulted in significant increase of the instant levels of arterial WSS, blood pressure, and OSI. During EECP treatment, the instant OSI level of the common carotid arteries over cardiac cycles raised to a mean value of 8.58 ×10-2±2.13 ×10-2. Meanwhile, the chronic intervention of EECP treatment significantly reduced the atherosclerotic lesions in abdominal aortas and the endothelial cellular adherence. The present study suggests that the unique blood flow pattern induced by EECP treatment and the augmentation of WSS level in cardiac cycles may be the most important hemodynamic mechanism that contribute to its anti-atherogenesis effect. And as one of the indices that cause great concern in current hemodynamic study, OSI may not play a key role during the initiation of atherosclerosis.