Iatrogenic coronary artery dissection is a complication of coronary intimal injury and dissection due to improper catheter manipulation. The impact of tear direction on the prognosis of coronary artery dissection (CAD) remains unclear. This study examines the hemodynamic effects of different tear directions (transverse and longitudinal) of CAD and evaluates the risk of thrombosis, rupture and further dilatation of CAD. Two types of CAD models (Type I: transverse tear, Type II: longitudinal tear) were reconstructed from the aorto-coronary CTA dataset of 8 healthy cases. Four WSS-based indicators were analyzed, including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and cross flow index (CFI). A thrombus growth model was also introduced to predict the trend of thrombus growth in CAD with two different tear directions. For most of the WSS-based indicators, including TAWSS, RRT, and CFI, no statistically significant differences were observed across the CAD models with varying tear directions, except for OSI, where a significant difference was noted ( < 0.05). Meanwhile, in terms of thrombus growth, the thrombus growing at the tear of the Type I (transverse tear) CAD model extended into the true lumen earlier than that of the Type II (longitudinal tear) model. Numerical simulations suggest that: (1) The CAD with transverse tear have a high risk of further tearing of the dissection at the distal end of the tear. (2) The CAD with longitudinal tear create a hemodynamic environment characterized by low TAWSS and high OSI in the false lumen, which may additionally increase the risk of vessel wall injury. (3) The CAD with transverse tear may have a higher risk of thrombosis and coronary obstruction and myocardial ischemia in the early phase of the dissection.

中文翻译：

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评估冠状动脉夹层撕裂方向对血栓形成的影响：血流动力学计算研究

医源性冠状动脉夹层是由于导管操作不当导致冠状动脉内膜损伤和夹层的并发症。撕裂方向对冠状动脉夹层（CAD）预后的影响尚不清楚。本研究探讨了 CAD 不同撕裂方向（横向和纵向）对血流动力学的影响，并评估 CAD 血栓形成、破裂和进一步扩张的风险。根据8例健康病例的主动脉-冠状动脉CTA数据集重建了两种类型的CAD模型（I型：横向撕裂，II型：纵向撕裂）。分析了四个基于 WSS 的指标，包括时间平均壁面剪应力 (TAWSS)、振荡剪切指数 (OSI)、相对停留时间 (RRT) 和错流指数 (CFI)。还引入了血栓生长模型来预测两种不同撕裂方向的 CAD 中血栓生长的趋势。对于大多数基于 WSS 的指标，包括 TAWSS、RRT 和 CFI，在具有不同撕裂方向的 CAD 模型中没有观察到统计学上的显着差异，但 OSI 除外，其中存在显着差异 ( < 0.05)。同时，在血栓生长方面，I型（横向撕裂）CAD模型撕裂处生长的血栓比II型（纵向撕裂）模型更早延伸到真腔。数值模拟表明：（1）存在横向撕裂的CAD在撕裂远端发生夹层进一步撕裂的风险较高。 (2) 具有纵向撕裂的 CAD 在假腔中产生了以低 TAWSS 和高 OSI 为特征的血流动力学环境，这可能另外增加血管壁损伤的风险。 (3)伴有横向撕裂的CAD在夹层早期发生血栓、冠状动脉阻塞和心肌缺血的风险较高。