Institute of Biomedical Engineering, University of Toronto, Toronto, Canada.
Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.
Ann Biomed Eng. 2021 Sep;49(9):2297-2310. doi: 10.1007/s10439-021-02771-6. Epub 2021 Apr 9.
Surgical repair of Tetralogy of Fallot (TOF) involves a series of steps to remove right ventricular outflow tract and pulmonary artery obstruction. However, the large degree of anatomic variability among preoperative TOF patients may impact the effectiveness of different repair strategies and, subsequently, different geometric modifications for different patients. This study investigates the relationships between geometric and hemodynamic parameters and mechanical energy efficiency for a patient-specific dataset of 16 postoperative TOF repairs, using morphometric and statistical shape analyses, as well as computational fluid dynamics simulations with physiologically-relevant inlet and outlet boundary conditions. Quantitatively, negative correlations were found between the right and left pulmonary artery centerline tract cumulative torsion and energy efficiency (r = - 0.65, p = 0.01, for both). A positive correlation was also found for a statistical shape mode associated with skewing of the geometric sub-regions (r = 0.61, p = 0.01). Qualitatively, medium- and low-efficiency geometries exhibit disturbed flow and much more proximal vortex formation as compared to a high-efficiency geometry. Thus, it is recommended, as much as possible, to both relieve and avoid the introduction of torsion into the patient's anatomy during surgical repair of TOF.
法洛四联症（TOF）的手术修复包括一系列步骤，以去除右心室流出道和肺动脉阻塞。然而，术前 TOF 患者的解剖学变异性很大，可能会影响不同修复策略的有效性，进而影响不同患者的不同几何修正。本研究使用形态计量学和统计形状分析，以及具有生理相关入口和出口边界条件的计算流体动力学模拟，对 16 例术后 TOF 修复的患者特定数据集的几何和血流动力学参数与机械能量效率之间的关系进行了研究。定量结果显示，右肺动脉和左肺动脉中心线轨迹的累积扭转与能量效率之间呈负相关（r = -0.65，p = 0.01，两者均如此）。与几何子区域偏斜相关的统计形状模式也呈正相关（r = 0.61，p = 0.01）。定性分析表明，与高效几何结构相比，中低效几何结构的血流紊乱，近端涡旋形成更多。因此，建议在 TOF 的手术修复过程中，尽可能减轻并避免将扭转引入患者的解剖结构中。
