Hemodynamics of patient-specific aorta-pulmonary shunt configurations

Abstract

Optimal hemodynamics in aorta-pulmonary shunt reconstruction is essential for improved post-operative recovery of the newborn congenital heart disease patient. However, prior to in vivo execution, the prediction of post-operative hemodynamics is extremely challenging due to the interplay of multiple confounding physiological factors. It is hypothesized that the post-operative performance of the surgical shunt can be predicted through computational blood flow simulations that consider patient size, shunt configuration, cardiac output and the complex three-dimensional disease anatomy. Utilizing only the routine patient-specific pre-surgery clinical data sets, we demonstrated an intelligent decision-making process for a real patient having pulmonary artery atresia and ventricular septal defect. For this patient, a total of 12 customized candidate shunt configurations are contemplated and reconstructed virtually using a sketch-based computer-aided anatomical editing tool. Candidate shunt configurations are evaluated based on the parameters that are computed from the flow simulations, which include 3D flow complexity, outlet flow splits, shunt patency, coronary perfusion and energy loss. Our results showed that the modified Blalock-Taussig (mBT) shunt has 12% higher right pulmonary artery (RPA) and 40% lower left pulmonary artery (LPA) flow compared to the central shunt configuration. Also, the RPA flow regime is distinct from the LPA, creating an uneven flow split at the pulmonary arteries. For all three shunt sizes, right mBT innominate and central configurations cause higher pulmonary artery (PA) flow and lower coronary artery pressure than right and left mBT subclavian configurations. While there is a trade-off between energy loss, flow split and coronary artery pressure, overall, the mBT shunts provide sufficient PA perfusion with higher coronary artery pressures and could be preferred for similar patients having PA overflow risk. Central shunts would be preferred otherwise particularly for cases with very low PA overflow risk.

Computational Pre-surgical Planning of Arterial Patch Reconstruction: Parametric Limits and In Vitro Validation

“…Pre-surgical hemodynamic planning15,43 integrated with the 3D rapid-prototyping technology12 has emerged as a useful tool in the surgical management of the complex congenital cardiovascular defects 29. Our recent investigations on the hemodynamic performance of right ventricular outflow conduits, suggested an improved performance when customized valve leakage area and orientation are considered 11.…”

In vitro validation of a self-driving aortic-turbine venous-assist device for Fontan patients

“…Even if higher drive power is required, the aortic flow extraction budget of iATVA can be increased beyond 10% to 20%, on the basis of the current experience with the first stage systemic-to-pulmonary shuts that are routinely used in staged single-ventricle palliation. Depending on the disease template, aortic steal through these shunts can reach up to 50% of the CO. 49 , 50 Likewise, when a Fontan fenestration is used, up to 30% preload increases are common. Furthermore, for shunt as well as fenestration systems the available hydrodynamic energy is expanded without doing any useful work and with oxygen desaturation.…”

Tetralogy of Fallot Surgical Repair: Shunt Configurations, Ductus Arteriosus and the Circle of Willis

“…The present study is a pilot investigation that focused on diseased type and shunt configurations, which will be expanded through larger shunt sizes, surgeon-specific shunt configurations and parametric pulmonary arterial diameters,45 including patient-specific anatomical cases as they become available 44. Computational results correspond to the time-averaged hemodynamics and exclude the deformation of the artery as well as the non-Newtonian effects.…”

“…Similar studies that investigate the hemodynamics of the 2nd stage shunt surgeries7,40 as well as the 1st stage surgical palliation are relatively rare 3–5,23,24,30,44. Furthermore the existing studies focused entirely on the surgical repair of HLHS48 in which the Norwood (innominate artery or the aorta shunt to the right pulmonary artery) and Sano (right ventricle to pulmonary artery shunt) shunt variations are analyzed 30.…”