Biomedical Flow Dynamics Laboratory, Tohoku University Institute of Fluid Science, Sendai, Miyagi, Japan.
Department of Neurosurgery, Saitama Medical University Saitama Medical Center, Kawagoe, Saitama, Japan.
J Neurointerv Surg. 2021 Feb;13(2):164-170. doi: 10.1136/neurintsurg-2020-016724. Epub 2020 Oct 23.
Despite a decade of research into virtual stent deployment and the post-stenting aneurysmal hemodynamics, the hemodynamic factors which correlate with successful treatment remain inconclusive. We aimed to examine the differences in various post-treatment hemodynamic parameters between successfully and unsuccessfully treated cases, and to quantify the additional flow diversion achievable through stent compaction or insertion of a second stent.
A systematic review and meta-analysis were performed on eligible studies published from 2000 to 2019. We first classified cases according to treatment success (aneurysm occlusion) and then calculated the pooled standardized mean differences (SMD) of each available parameter to examine their association with clinical outcomes. Any additional flow diversion arising from the two common strategies for improving the stent wire density was quantified by pooling the results of such studies.
We found that differences in the aneurysmal inflow rate (SMD -6.05, 95% CI -10.87 to -1.23, p=0.01) and energy loss (SMD -5.28, 95% CI -7.09 to -3.46, p<0.001) between the successfully and unsuccessfully treated groups were indicative of statistical significance, in contrast to wall shear stress (p=0.37), intra-aneurysmal average velocity (p=0.09), vortex core-line length (p=0.46), and shear rate (p=0.09). Compacting a single stent could achieve additional flow diversion comparable to that by dual-stent implantation.
Inflow rate and energy loss have shown promise as identifiers to discriminate between successful and unsuccessful treatment, pending future research into their diagnostic performance to establish optimal cut-off values.
尽管在虚拟支架置入和支架置入后动脉瘤血流动力学方面已经开展了十年的研究，但与成功治疗相关的血流动力学因素仍不确定。我们旨在研究治疗成功和治疗失败病例之间各种治疗后血流动力学参数的差异，并量化支架压缩或置入第二个支架可增加的分流。
对 2000 年至 2019 年发表的合格研究进行系统回顾和荟萃分析。我们首先根据治疗成功（动脉瘤闭塞）对病例进行分类，然后计算每个可用参数的汇总标准化均数差值（SMD），以研究它们与临床结果的相关性。通过汇总此类研究的结果，量化了通过两种常见策略改善支架线密度可增加的任何额外分流。
我们发现，成功治疗组和治疗失败组之间的动脉瘤流入率（SMD -6.05，95%CI -10.87 至 -1.23，p=0.01）和能量损失（SMD -5.28，95%CI -7.09 至 -3.46，p<0.001）存在差异具有统计学意义，而壁切应力（p=0.37）、动脉瘤内平均速度（p=0.09）、涡旋核心线长度（p=0.46）和剪切率（p=0.09）则无差异。压缩单个支架可实现与双支架植入相当的额外分流。
流入率和能量损失已显示出作为区分成功和失败治疗的标志物的潜力，需要进一步研究其诊断性能以确定最佳截断值。
