Sidora Gurnish, Haley Anna L, Cancelliere Nicole M, Pereira Vitor M, Steinman David A
Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.
Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Ontario, Canada.
J Neurointerv Surg. 2025 Aug 13;17(9):1005-1010. doi: 10.1136/jnis-2024-022074.
Venous sinus stenosis can be associated with cerebrovascular disorders. Understanding the role of blood flow disturbances in these disorders is often hampered by the lack of patient-specific flow rates. Our goal was to demonstrate the impact of this by predicting individual flow rates retrospectively from routine manometry and angiography.
Ten cases, spanning a range of stenosis severities and pressure gradients, were selected from a cohort of patients who had undergone venous stenting for pulsatile tinnitus. Lumen geometries were digitally segmented from CT venograms. A simplified Bernoulli formula was derived to estimate individual cycle-average flow rates from clinical pressure gradients and minimum lumen cross-section areas. High-fidelity pulsatile computational fluid dynamics (CFD) simulations were performed to compare predictions of flow disturbances using generic versus individual flow rates, and to validate the Bernoulli formula.
Individual flow rates derived from the Bernoulli formula deviated by up to 47% from the assumed generic flow rate, resulting in substantial differences in CFD predictions of post-stenotic flow instabilities. Pressure gradients estimated by the simplified Bernoulli formula were, however, highly predictive of pressure gradients from the full CFD simulations (R=0.95; slope=0.98, 95% CI 0.88 to 1.09).
A simple Bernoulli formula can predict CFD-estimated trans-stenotic pressure gradients in realistic venous geometries. As demonstrated here, this may be used to recover individual flow rates from routine-but-invasive clinical measurements; however, it also suggests a simpler path towards non-invasive estimation of trans-stenotic pressure gradients that may avoid some of the challenges associated with 4D flow MRI approaches.
静脉窦狭窄可能与脑血管疾病相关。由于缺乏患者特异性流速，了解血流紊乱在这些疾病中的作用常常受到阻碍。我们的目标是通过回顾性地从常规测压和血管造影预测个体流速来证明其影响。
从因搏动性耳鸣接受静脉支架置入术的患者队列中选择10例病例，涵盖一系列狭窄严重程度和压力梯度。从CT静脉造影中对管腔几何形状进行数字分割。推导了一个简化的伯努利公式，以根据临床压力梯度和最小管腔横截面积估计个体周期平均流速。进行了高保真搏动计算流体动力学（CFD）模拟，以比较使用通用流速与个体流速对血流紊乱的预测，并验证伯努利公式。
从伯努利公式得出的个体流速与假定的通用流速偏差高达47%，导致对狭窄后血流不稳定性的CFD预测存在显著差异。然而，简化伯努利公式估计的压力梯度与完整CFD模拟的压力梯度具有高度预测性（R=0.95；斜率=0.98，95%CI为0.88至1.09）。
一个简单的伯努利公式可以预测实际静脉几何形状中CFD估计的跨狭窄压力梯度。如此处所示，这可用于从常规但有创的临床测量中恢复个体流速；然而，这也提示了一条通往跨狭窄压力梯度无创估计的更简单途径，可能避免与4D流MRI方法相关的一些挑战。
