Effects of Patent Ductus Arteriosus on the Hemodynamics of Modified Blalock–Taussig Shunt Based on Patient-Specific Simulation

Abstract

The question of preserving the patent ductus arteriosus (PDA) during the modified Blalock–Taussig shunt (MBTS) procedure remains controversial. The goal of this study was to investigate the effects of the PDA on the flow features of the MBTS to help with preoperative surgery design and postoperative prediction. In this study, a patient with pulmonary atresia and PDA was included. A patient-specific three-dimensional model was reconstructed, and virtual surgeries of shunt insertion and ductus ligation were performed using computer-aided design. Computational fluid dynamics was utilized to analyze the hemodynamic parameters of varied models based on the patient-specific anatomy and physiological data. The preservation of the PDA competitively reduced the shunt flow but increased total pulmonary perfusion. The shunt flow and ductal flow collided, causing significant and complicated turbulence in the pulmonary artery where low wall shear stress, high oscillatory shear index, and high relative residence time were distributed. The highest energy loss was found when the PDA was preserved. The preservation of PDA is not recommended during MBTS procedures because it negatively influences hemodynamics. This may lead to pulmonary overperfusion, inadequate systemic perfusion, and a heavier cardiac burden, thus increasing the risk of heart failure. Also, it seems to bring no benefit in terms of reducing the risk for thrombosis.

Investigation of the influence of intersystem shunt characteristics on hemodynamic parameters and oxygen distribution

“…Значения осредненных за сердечный цикл пристеночных касательных напряжений в пиковый момент систолы достигают максимальных значений в области шунта, что может способствовать тромбозу шунта [41,42]. Кроме того, высокие значения касательных напряжений наблюдаются в области вихревого движения крови в нижней части легочной артерии [43].…”

“…Особенно это выражено у пациента 2 при центральном расположении шунта и у пациента 3 при левом расположении шунта. В работах [12,43] исследователи пришли к схожим результатам, выявив асимметричное распределение кровотока в легочных артериях независимо от места установки межсистемного шунта.…”

“…Для пациента 3 правое расположение приводит к меньшим потерям энергии по сравнению с шунтами того же размера, но другого расположения. Другие авторы в своих исследованиях тоже говорят о негативном влиянии больших значений EL на сердечно-сосудистую систему, в частности сердце и его миокард [43]. В работе [12] была проанализирована потеря энергии и получены результаты в диапазоне 0.065-0.15 Вт.…”

Multiscale Modeling Is Required for the Patent Ductus Arteriosus in Preterm Infants

“…On the other hand, if the modeling goal is to investigate the detailed 3D flow patterns, e.g., the formation of vortex and flow separations after constriction in PDA, and the wall shear stress, then a 3D flow model should be applied ( 19 , 20 ). A recent model simulated the 3D flow in the PDA to investigate the effects of the PDA on the flow features of the modified Blalock-Taussig shunt ( 21 ). Another study investigated the 3D flow in the PDA with respect to three typical pulmonary artery (PA) dysplasia structures and different sizes of PDA ( 22 ).…”