Liu Xin, Dornbos David, Pu Yuehua, Leng Xinyi, Song Ligang, Jia Baixue, Pan Yuesong, Wang David, Miao Zhongrong, Wang Yilong, Liu Liping, Wang Yongjun
a Department of Neurology , Beijing Tiantan Hospital, Capital Medical University , Beijing , China.
b Department of Neurological Surgery , The Ohio State University Wexner Medical Center , Columbus , OH , USA.
Neurol Res. 2017 Jun;39(6):498-503. doi: 10.1080/01616412.2017.1315483. Epub 2017 Apr 23.
Fractional flow reserve (FFR) accurately predicts the degree of stenosis and is now widely used to identify clinically significant severe coronary artery lesions. In the current study, we utilized a similar indicator, fractional flow (FF), to determine the hemodynamic impact of symptomatic intracranial atherosclerotic stenosis (ICAS) and to assess the correlation of FF with the severity of stenosis and collateral circulation.
Patients with symptomatic ICAS (70-99% stenosis) confirmed on digital subtraction angiography (DSA) were consecutively recruited. FF was obtained during DSA examination with the use of pressure sensors and was measured as a ratio, comparing measurements distal to an ICAS lesion (Pd) and within the aorta (Pa). The degree of leptomeningeal collateralization was graded from zero (absent) to four (complete compensatory). The correlation between FF, anatomical stenosis, and collateral status was then analyzed.
Twenty-five patients with a mean age of 55.6 years were analyzed. The median percentage of stenosis and median FF were 82.3 and 0.68%, respectively. Eleven patients were found to have poor collateralization (grade 0-2), and fourteen patients were identified with good collateral circulation (grade 3-4). Overall, the hemodynamic impact of an atherosclerotic lesions worsened (decreased FF) as the percentage of stenosis increased, although this did not reach statistical significance (r = -0.398, p = 0.06). However, the status of collateralization significantly altered this correlation, worsening the hemodynamic impact in patients with poor collateral circulation (r = -0.677, p = 0.032). There was no difference in patients with good collateral circulation (r = -0.279, p = 0.356).
An anatomically severe (70-99%) symptomatic ICAS lesion may generate significant hemodynamic stress downstream as assessed by the indicator FF, particularly in patients with poor collateral circulation. Further, good collateralization may mitigate this hemodynamic impact, partially explaining the protective effect of collateral circulation against recurrent stroke in such patients.
血流储备分数（FFR）能准确预测狭窄程度，目前已广泛用于识别具有临床意义的严重冠状动脉病变。在本研究中，我们使用了一种类似的指标，即血流分数（FF），来确定有症状的颅内动脉粥样硬化狭窄（ICAS）的血流动力学影响，并评估FF与狭窄严重程度及侧支循环的相关性。
连续纳入经数字减影血管造影（DSA）证实为有症状ICAS（狭窄70%-99%）的患者。在DSA检查期间使用压力传感器获取FF，并将其测量为一个比值，即比较ICAS病变远端（Pd）和主动脉内（Pa）的测量值。软脑膜侧支循环程度从零（无）到四级（完全代偿）进行分级。然后分析FF、解剖学狭窄和侧支状态之间的相关性。
分析了25例平均年龄为55.6岁的患者。狭窄的中位数百分比和FF中位数分别为82.3%和0.68%。发现11例患者侧支循环不良（0-2级），14例患者侧支循环良好（3-4级）。总体而言，随着狭窄百分比增加，动脉粥样硬化病变的血流动力学影响恶化（FF降低），尽管这未达到统计学意义（r = -0.398，p = 0.06）。然而，侧支循环状态显著改变了这种相关性，使侧支循环不良患者的血流动力学影响恶化（r = -0.677，p = 0.032）。侧支循环良好的患者之间无差异（r = -0.279，p = 0.356）。
通过FF指标评估，解剖学上严重（70%-99%）的有症状ICAS病变可能在下游产生显著的血流动力学应激，特别是在侧支循环不良的患者中。此外，良好的侧支循环可能减轻这种血流动力学影响，部分解释了侧支循环对这类患者复发性卒中的保护作用。
