Kuribara Tomoyoshi, Mikami Takeshi, Iihoshi Satoshi, Hirano Toru, Sasamori Daisuke, Nonaka Tadashi, Mikuni Nobuhiro
Department of Neurosurgery, Sapporo Medical University, Sapporo, Hokkaido, Japan.
Department of Endovascular Neurosurgery, Saitama Medical University, International Medical Center, Hidaka, Saitama, Japan.
Surg Neurol Int. 2021 Jul 27;12:378. doi: 10.25259/SNI_439_2021. eCollection 2021.
Ischemic tolerance has been evaluated by the balloon test occlusion (BTO) for cerebral aneurysms and tumors that might require parent artery occlusion during surgery. However, because of its invasiveness, a non-invasive evaluation method is needed. In this study, we assessed the possibility of virtual test occlusion using computational fluid dynamics (CFD) as a non-invasive alternative to BTO for evaluating ischemic tolerance.
Twenty-one patients who underwent BTO were included in the study. Virtual test occlusion was performed using CFD analysis, and the flow rate (FR) and wall shear stress (WSS) of the middle cerebral artery on the occlusion side were calculated. The correlations between these parameters and examination data including the parameters of computed tomography perfusion during BTO were assessed and the cutoff value of CFD parameters for detecting the good collateral group was calculated.
The FR was strongly correlated with mean transit time (MTT) during BTO and moderately correlated with collateral flow grade based on angiographic appearance. The WSS was moderately correlated with collateral flow grade, mean stump pressure (MSP), and MTT. Furthermore, the FR and WSS were strongly correlated with the total FR and the diameters of the inlet vessels. The cutoff value of FR for detecting the good collateral group was 126.2 mL/min, while that of the WSS was 4.54 Pa.
The parameters obtained through CFD analysis were correlated with collateral flow grade and MSP in addition to MTT. CFD analysis may be useful to evaluate ischemic tolerance as a non-invasive alternative to BTO.
对于可能在手术中需要闭塞供血动脉的脑动脉瘤和肿瘤，已通过球囊试验闭塞（BTO）来评估缺血耐受性。然而，由于其具有侵入性，需要一种非侵入性评估方法。在本研究中，我们评估了使用计算流体动力学（CFD）进行虚拟试验闭塞作为BTO的非侵入性替代方法来评估缺血耐受性的可能性。
本研究纳入了21例行BTO的患者。使用CFD分析进行虚拟试验闭塞，并计算闭塞侧大脑中动脉的血流速度（FR）和壁面剪应力（WSS）。评估这些参数与包括BTO期间计算机断层扫描灌注参数在内的检查数据之间的相关性，并计算用于检测良好侧支循环组的CFD参数的截断值。
FR与BTO期间的平均通过时间（MTT）密切相关，与基于血管造影表现的侧支血流分级中度相关。WSS与侧支血流分级、平均残端压力（MSP）和MTT中度相关。此外，FR和WSS与总FR及入路血管直径密切相关。检测良好侧支循环组的FR截断值为126.2 mL/min，而WSS的截断值为4.54 Pa。
通过CFD分析获得的参数除了与MTT相关外，还与侧支血流分级和MSP相关。CFD分析作为BTO的非侵入性替代方法，可能有助于评估缺血耐受性。
