Jain Mika S, Telischak Nicholas A, Heit Jeremy J, Do Huy M, Massoud Tarik F
Departments of Physics and Computer Science, Stanford University School of Humanities and Sciences, Stanford, California, USA.
Division of Neuroimaging and Neurointervention, Department of Radiology, and Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA.
J Neurointerv Surg. 2022 Dec;14(12):1213-1219. doi: 10.1136/neurintsurg-2021-018067. Epub 2021 Dec 10.
High-flow fistulas related to plexiform nidi are found in 40% of large brain arteriovenous malformations (AVMs). Endovascular occlusion of intranidal fistulas before plexiform components is empirically considered safe, but potential ensuing dangerous re-routing of flow through plexiform vessels may in theory raise their rupture risk. It remains unclear whether it is safer to embolize plexiform or fistulous vessels initially. We used a novel biomathematical AVM model to compare theoretical hemodynamic changes and rupture risks on sequential embolizations of both types of nidus vessels.
We computationally modeled a theoretical AVM as an electrical circuit containing a nidus consisting of a massive stochastic network ensemble comprising 1000 vessels. We sampled and individually simulated 10 000 different nidus morphologies with a fistula angioarchitecturally isolated from its adjacent plexiform nidus. We used network analysis to calculate mean intravascular pressure (P) and flow rate within each nidus vessel; and Monte Carlo analysis to assess overall risks of nidus rupture when simulating sequential occlusions of vessel types in all 10 000 nidi.
We consistently observed lower nidus rupture risks with initial fistula occlusion in different network morphologies. Intranidal fistula occlusion simultaneously reduced P and flow rate within draining veins.
Initial occlusion of AVM fistulas theoretically reduces downstream draining vessel hypertension and lowers the risk of rupture of an adjoining plexiform nidus component. This mitigates the theoretical concern that fistula occlusion may cause dangerous redistribution of hemodynamic forces into plexiform nidus vessels, and supports a clinical strategy favoring AVM fistula occlusion before plexiform nidus embolization.
在40%的大型脑动静脉畸形（AVM）中发现与丛状巢相关的高流量瘘。在处理丛状成分之前对巢内瘘进行血管内闭塞在经验上被认为是安全的，但理论上，随后通过丛状血管的血流重新分布可能会增加其破裂风险。最初栓塞丛状血管还是瘘管血管哪种更安全仍不清楚。我们使用一种新型生物数学AVM模型来比较两种类型巢血管序贯栓塞时的理论血流动力学变化和破裂风险。
我们将一个理论性AVM计算建模为一个电路，其中包含一个由1000条血管组成的大量随机网络集合构成的巢。我们对10000种不同的巢形态进行采样并单独模拟，其中瘘管在血管造影结构上与其相邻的丛状巢分离。我们使用网络分析来计算每个巢血管内的平均血管内压力（P）和流速；并使用蒙特卡罗分析来评估在模拟所有10000个巢中血管类型的序贯闭塞时巢破裂的总体风险。
在不同的网络形态中，我们一致观察到初始瘘管闭塞时巢破裂风险较低。巢内瘘管闭塞同时降低了引流静脉内的P和流速。
理论上，AVM瘘管的初始闭塞可降低下游引流血管的高血压，并降低相邻丛状巢成分破裂的风险。这减轻了关于瘘管闭塞可能导致血流动力学力量危险地重新分布到丛状巢血管中的理论担忧，并支持一种在栓塞丛状巢之前优先进行AVM瘘管闭塞的临床策略。
