Optimizing cerebral perfusion and hemodynamics during cardiopulmonary bypass through cannula design combining in silico, in vitro and in vivo input

Abstract

Cardiopulmonary bypass (CPB) is a standard technique for cardiac surgery, but comes with the risk of severe neurological complications (e.g. stroke) caused by embolisms and/or reduced cerebral perfusion. We report on an aortic cannula prototype design (optiCAN) with helical outflow and jet-splitting dispersion tip that could reduce the risk of embolic events and restores cerebral perfusion to 97.5% of physiological flow during CPB in vivo, whereas a commercial curved-tip cannula yields 74.6%. In further in vitro comparison, pressure loss and hemolysis parameters of optiCAN remain unaffected. Results are reproducibly confirmed in silico for an exemplary human aortic anatomy via computational fluid dynamics (CFD) simulations. Based on CFD simulations, we firstly show that optiCAN design improves aortic root washout, which reduces the risk of thromboembolism. Secondly, we identify regions of the aortic intima with increased risk of plaque release by correlating areas of enhanced plaque growth and high wall shear stresses (WSS). From this we propose another easy-to-manufacture cannula design (opti2CAN) that decreases areas burdened by high WSS, while preserving physiological cerebral flow and favorable hemodynamics. With this novel cannula design, we propose a cannulation option to reduce neurological complications and the prevalence of stroke in high-risk patients after CPB.

Evaluation of Different Cannulation Strategies for Aortic Arch Surgery Using a Cardiovascular Numerical Simulator

“…The effect of arterial filtration on cerebral auto-regulation [73,74] and the choice of pH management [75] has also been addressed. A combined experimental and computational approach may have a role to play with the optimisation of cerebral blood flow on cardiopulmonary bypass in terms of a reduction in neurological events [76,77]. The presence of carotid or intracranial atherosclerotic disease does not seem to affect the incidence of stroke during aortic arch surgery, whilst its perioperative cause remains predominantly embolic [78].…”

Improving Circulatory Support in Cases of Acute DeBakey Type I Aortic Dissection: A Novel Arterial Cannulation Approach and Its Effects on Perfusion and Minimizing Complications

“…However, these conventional approaches pose challenges for patients with extensive involvement of the aortic arch and its three branches. Tese methods can result in elevated intraoperative perfusion pressure, excessive cerebral perfusion, and inadequate systemic organ perfusion [4]. Tese factors are closely associated with poor patient outcomes.…”

A Computational Fluid Dynamics Study to Compare Two Types of Arterial Cannulae for Cardiopulmonary Bypass

“…Several contributions described the CFD analysis to investigate the flow pattern induced by the aortic cannula during CPB [14][15][16][17] or in the presence of aortic pathologies [18,19]. Over recent years, the development and improvement of the aortic cannulation procedure has been the subject of enormous interest.…”

“…Deng et al [15] used a numerical model based on computational fluid dynamics to analyze the difference of several cannulation methods on the blood flow property in a type A aortic dissection (TAAD) model. Hungeroth et al [16] dealt with an outflow-optimized cannula design (optiCAN), which was improved using computational fluid dynamics models, prototyped, and tested in vitro as well as in vivo. In Caruso et al [17], a comparative multi-scale study was performed, by coupling three-dimensional computational fluid dynamics and a 0D model in order to establish the modifications of blood flow caused by the changes in the cannula insertion angle during a cardiopulmonary bypass.…”