Incomplete stent expansion (IncSE) is occasionally seen in flow-diversion (FD) treatment of intracranial aneurysms; however, its haemodynamic consequences remain inconclusive. Through a parametric study, we quantify the aneurysmal haemodynamics subject to different severities of IncSE occurring in different portions of the stent. Two patient cases with IncSE confirmed in vivo were studied. To investigate a wider variety of IncSE scenarios, we modelled IncSE at two severity levels respectively located in the proximal, central, or distal segment of a stent, yielding a total of 14 treatment scenarios (including the ideal deployment). We examined stent wire configurations in 14 scenarios and resolved aneurysm haemodynamics through computational fluid dynamics (CFD). A considerable degradation of aneurysm flow-reduction performance was observed when central or distal IncSE occurred, with the maximal elevations of the inflow rate (IR) and energy loss (EL) being 10% and 15%. The underlying mechanism might be the increased resistance for flow to remain within the FD stent, which forces more blood to leak into the aneurysm sac. Counter-intuitively, a slight reduction of aneurysm inflow was associated with proximal IncSE, with the maximal further reduction of the IR and EL being 5% and 8%. This may be due to the disruption of the predominant parent-artery flow by the collapsed wires, which decreased the strength and altered the direction of aneurysmal inflow. The effects of IncSE vary greatly with the location of occurrence, revealing the importance of performing individualised, patient-specific risk assessment before treatment.

中文翻译：

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分流治疗中支架扩张不完全影响动脉瘤血流动力学：对载瘤动脉不同节段发生不同严重程度贴壁不良影响的治疗进行定量比较

不完全支架扩张 (IncSE) 偶尔会出现在颅内动脉瘤的分流 (FD) 治疗中；然而，其血液动力学后果仍无定论。通过参数研究，我们量化了在支架不同部分发生的不同严重程度的 IncSE 下的动脉瘤血流动力学。研究了两个体内确认的 IncSE 患者病例。为了研究更广泛的 IncSE 场景，我们对分别位于支架近端、中央或远端部分的两个严重程度级别的 IncSE 进行建模，产生总共 14 种治疗场景（包括理想部署）。我们检查了 14 种情况下的支架线配置，并通过计算流体动力学 (CFD) 解决了动脉瘤血流动力学问题。当发生中央或远端 IncSE 时，观察到动脉瘤流量减少性能显着下降，流入速率 (IR) 和能量损失 (EL) 的最大升高分别为 10% 和 15%。潜在的机制可能是增加了流动在 FD 支架内的阻力，这迫使更多的血液泄漏到动脉瘤囊中。与直觉相反，动脉瘤流入量的轻微减少与近端 IncSE 相关，IR 和 EL 的最大进一步减少分别为 5% 和 8%。这可能是由于塌陷的导线破坏了主要的母动脉流动，从而降低了强度并改变了动脉瘤流入的方向。IncSE 的影响随着发生地点的不同而有很大差异，揭示了执行个性化、