Sughimoto Koichi, Takahara Yoshiharu, Mogi Kenji, Yamazaki Kenji, Tsubota Ken'ichi, Liang Fuyou, Liu Hao
Department of Cardiac Surgery, The Royal Children's Hospital Melbourne, 50 Flemington Rd, Parkville, VIC, 3052, Australia,
Heart Vessels. 2014 May;29(3):404-12. doi: 10.1007/s00380-013-0381-7. Epub 2013 Jul 14.
Aortic aneurysms may cause the turbulence of blood flow and result in the energy loss of the blood flow, while grafting of the dilated aorta may ameliorate these hemodynamic disturbances, contributing to the alleviation of the energy efficiency of blood flow delivery. However, evaluating of the energy efficiency of blood flow in an aortic aneurysm has been technically difficult to estimate and not comprehensively understood yet. We devised a multiscale computational biomechanical model, introducing novel flow indices, to investigate a single male patient with multiple aortic aneurysms. Preoperative levels of wall shear stress and oscillatory shear index (OSI) were elevated but declined after staged grafting procedures: OSI decreased from 0.280 to 0.257 (first operation) and 0.221 (second operation). Graftings may strategically counter the loss of efficient blood delivery to improve hemodynamics of the aorta. The energy efficiency of blood flow also improved postoperatively. Novel indices of pulsatile pressure index (PPI) and pulsatile energy loss index (PELI) were evaluated to characterize and quantify energy loss of pulsatile blood flow. Mean PPI decreased from 0.445 to 0.423 (first operation) and 0.359 (second operation), respectively; while the preoperative PELI of 0.986 dropped to 0.820 and 0.831. Graftings contributed not only to ameliorate wall shear stress or oscillatory shear index but also to improve efficient blood flow. This patient-specific modeling will help in analyzing the mechanism of aortic aneurysm formation and may play an important role in quantifying the energy efficiency or loss in blood delivery.
主动脉瘤可能导致血流紊乱并造成血流能量损失，而对扩张的主动脉进行移植可改善这些血液动力学紊乱，有助于提高血流输送的能量效率。然而，评估主动脉瘤内血流的能量效率在技术上一直难以估计，且尚未得到全面理解。我们设计了一个多尺度计算生物力学模型，引入了新的血流指数，以研究一名患有多个主动脉瘤的男性患者。术前壁面切应力和振荡切变指数（OSI）水平升高，但在分期移植手术后下降：OSI从0.280降至0.257（第一次手术）和0.221（第二次手术）。移植可能从策略上对抗有效血液输送的损失，以改善主动脉的血液动力学。术后血流的能量效率也有所提高。评估了搏动压力指数（PPI）和搏动能量损失指数（PELI）的新指数，以表征和量化搏动血流的能量损失。平均PPI分别从0.445降至0.423（第一次手术）和0.359（第二次手术）；而术前的PELI为0.986，降至0.820和0.831。移植不仅有助于改善壁面切应力或振荡切变指数，还有助于改善有效血流。这种针对患者的建模将有助于分析主动脉瘤形成的机制，并可能在量化血液输送中的能量效率或损失方面发挥重要作用。
