Baráth Krisztina, Cassot Francis, Rüfenacht Daniel A, Fasel Jean H D
Department of Radiology, University Hospital of Geneva, Rue Micheli-du-Crest 24, CH-1211 Geneva 14, Switzerland.
AJNR Am J Neuroradiol. 2004 Nov-Dec;25(10):1750-9.
Stent implantation alone might not be sufficient to produce definitive treatment of cerebral aneurysms. Therefore, extended experimental work is needed to improve results. We show the feasibility of using an in vitro anatomically shaped elastic model for flow evaluation before and after stent implantation.
Based on human vascular casting, an anatomic elastic internal carotid artery model, including an aneurysm on the supraclinoid portion, was manufactured. The model was connected to a circulatory loop to simulate physiological flow. After visualization of the flow by using glass particles and laser sheet translumination, the digitally recorded data were transferred for computer analysis. Intra-saccular flow pattern changes and the vortex velocity reduction induced by the stent were investigated qualitatively and quantitatively.
The distal neck of the aneurysm behaved as a flow divider. Therefore, it was directly exposed to the hemodynamic stress. Inside the sac, a well-defined vortex formed and progressed along the wall toward the proximal neck. After stent implantation this pattern changed significantly; the vortex appeared more dispersed and its residence time increased. The velocity reduction was 32%. Velocity peak was observed close to the distal neck in both cases.
In vitro anatomic elastic models are feasible for flow evaluation with laser sheet translumination. In our model, stent implantation resulted in hemodynamic changes that might favor the exclusion of the aneurysm from the circulation and can prevent regrowth of the aneurysmal sac.
单纯的支架植入可能不足以对脑动脉瘤进行彻底治疗。因此，需要开展更多的实验工作来改善治疗效果。我们展示了使用体外解剖形状的弹性模型来评估支架植入前后血流情况的可行性。
基于人体血管铸型，制作了一个解剖学弹性颈内动脉模型，该模型包括床突上段的一个动脉瘤。将该模型连接到一个循环回路以模拟生理血流。使用玻璃颗粒和激光片透射法对血流进行可视化后，将数字记录的数据传输至计算机进行分析。定性和定量研究了支架引起的瘤内血流模式变化和涡流速度降低情况。
动脉瘤的远端颈部起到了分流器的作用。因此，它直接暴露于血流动力学应力之下。在瘤腔内，形成了一个明确的涡流，并沿着壁向近端颈部发展。支架植入后，这种模式发生了显著变化；涡流看起来更加分散，其停留时间增加。速度降低了32%。在两种情况下，速度峰值均出现在靠近远端颈部的位置。
体外解剖弹性模型对于使用激光片透射法进行血流评估是可行的。在我们的模型中，支架植入导致了血流动力学变化，这可能有利于将动脉瘤排除在循环之外，并可防止动脉瘤囊的再生长。
