Migliavacca Francesco, Balossino Rossella, Pennati Giancarlo, Dubini Gabriele, Hsia Tain-Yen, de Leval Marc R, Bove Edward L
Laboratory of Biological Structure Mechanics, Department of Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan, Italy.
J Biomech. 2006;39(6):1010-20. doi: 10.1016/j.jbiomech.2005.02.021. Epub 2005 Apr 25.
Multiscale computing is a challenging area even in biomechanics. Application of such a methodology to quantitatively compare postoperative hemodynamics in congenital heart diseases is very promising. In the treatment of hypoplastic left heart syndrome, which is a congenital heart disease where the left ventricle is missing or very small, the necessity to feed the pulmonary and systemic circulations is obtained with an interposition shunt. Two main options are available and differ from the sites of anastomoses: (i) the systemic-to-pulmonary conduit (Blalock-Taussig shunt known as the Norwood Operation (NO)) connecting the innominate artery (NO-BT) or the aorta (NO-CS) to the right pulmonary artery and (ii) the right ventricle to pulmonary artery shunt (known as Sano operation (SO)). The proposition that the SO is superior to the NO remains controversial. 3-D computer models of the NO (NO-BT and NO-CS) and SO were developed and investigated using the finite volume method. Conduits of 3, 3.5 and 4 mm were used in the NO models, whereas conduits of 4, 5 and 6 mm were used in the SO model. The hydraulic nets (lumped resistances, compliances, inertances and elastances) which represent the systemic, coronary and pulmonary circulations and the heart were identical in the two models. A multiscale approach was adopted to couple the 3-D models with the circulation net. Computer simulation results were compared with post-operative catheterization data. Results showed that (i) there is a good correlation between predicted and observed data: higher aortic diastolic pressure, decreased pulmonary arterial pressure, lower pulmonary-to-systemic flow ratio and higher coronary perfusion pressure in SO; (ii) there is a minimal regurgitant flow in the SO conduit. The close correlation between predicted and observed clinical data supports the use of mathematical modelling, with a mandatory multiscale approach, in the design and assessment of surgical procedures.
即使在生物力学领域，多尺度计算也是一个具有挑战性的领域。将这种方法应用于定量比较先天性心脏病术后的血流动力学非常有前景。在左心发育不全综合征（一种左心室缺失或非常小的先天性心脏病）的治疗中，通过插入分流术来满足肺循环和体循环的供血需求。有两种主要选择，它们在吻合部位有所不同：（i）体肺分流管（称为诺伍德手术（NO）的布莱洛克 - 陶西格分流术），将无名动脉（NO - BT）或主动脉（NO - CS）与右肺动脉相连；（ii）右心室到肺动脉分流术（称为佐野手术（SO））。关于SO优于NO的观点仍存在争议。利用有限体积法开发并研究了NO（NO - BT和NO - CS）和SO的三维计算机模型。NO模型中使用了3毫米、3.5毫米和4毫米的分流管，而SO模型中使用了4毫米、5毫米和6毫米的分流管。在这两个模型中，代表体循环、冠状动脉循环、肺循环和心脏的水力网络（集中电阻、顺应性、惯性和弹性）是相同的。采用多尺度方法将三维模型与循环网络耦合。将计算机模拟结果与术后导管插入术数据进行比较。结果表明：（i）预测数据与观察数据之间具有良好的相关性：SO中主动脉舒张压更高、肺动脉压降低、肺循环与体循环血流量比值更低且冠状动脉灌注压更高；（ii）SO分流管中的反流流量最小。预测临床数据与观察临床数据之间的密切相关性支持在手术程序的设计和评估中使用数学建模，并采用强制性的多尺度方法。
