Low wall shear stress is associated with the rupture of intracranial aneurysm with known rupture point: case report and literature review

Abstract

BackgroundFew previous hemodynamic studies demonstrated the detailed features of rupture point of intracranial aneurysms. The hemodynamic simulation for the case that ruptured during angiography was even rare. In the present study, we studied the hemodynamic characteristics of a posterior communicating artery segment aneurysm that ruptured during angiography and detailed the hemodynamic features at the rupture point.Case presentationOne 64-years-patient was 60–69 years old and suffered a subarachnoid hemorrhage within 24 h. Standard digital subtraction angiography and three-dimensional (3D) rotational angiography were performed and an 8 mm left posterior communicating artery segment aneurysm was found. The patient had a seizure immediately following 3D angiography for about 40 s and the immediate follow-up angiography showed contrast extravasation from the tip of identified aneurysms. The consequent vital sign of the patient became unstable. Urgent embolization under general anesthesia was planned, but the relatives refused interventional operation considering the high risk of procedure and poor condition of the patient. The computational fluid dynamic (CFD) method was used to evaluate the hemodynamic characteristics at rupture point, and the results showed that the rupture point was associated with markedly low wall shear stress and high oscillatory shear index without flow impingement.ConclusionsWe present a rare case of which the rupture site was identified during angiography. The hemodynamic simulations revealed that the rupture point was associated with markedly low WSS and high OSI without flow impingement. The result may be unique to this particular aneurysm; however, our findings provide insight into the hemodynamics of rupture point.Electronic supplementary materialThe online version of this article (doi:10.1186/s12883-016-0759-0) contains supplementary material, which is available to authorized users.

Low Wall Shear Stress Is Associated with Local Aneurysm Wall Enhancement on High-Resolution MR Vessel Wall Imaging

“…In addition, in studies on ruptured aneurysms, low WSS was associated with the aneurysm rupture point. 10,20,22,23 In our study, low WSS was also associated with a local enhanced area of the aneurysm wall; the association indicates that the enhanced area may also be the weak part of aneurysm wall. In addition, there were no statistically significant hemodynamic differences between the ruptured and unruptured aneurysms, which indicates that these unruptured aneurysms with local wall enhancement may have a potential risk similar to that of ruptured aneurysms.…”

“…Several studies also suggested that applying directly to the en- dothelial cells and acting as a mechanobiological trigger, low WSS may predispose the region to the dysfunction of flow-induced nitric oxide, upgrade endothelial surface adhesion molecules, promote the permeability of endothelial cells, and, thus, facilitate atherosclerotic and inflammatory cell infiltration. 10,14,[19][20][21] Edjlali et al 3 proposed the potential of low WSS in monitoring the aneurysm wall inflammatory process. Hu et al 4 collected a specimen of the aneurysm wall from a patient intraoperatively, which had exhibited local wall enhancement on the high-resolution MRI, and the following histologic study revealed phagocyte and lymphocyte invasion.…”

“…A laminar and incompressible blood flow, with density and viscosity set as 1060 kg/m 3 and 0.004 Pa ⅐ s, respectively, was used in the calculation. 10 The pulsatile velocity profile of the ICA, which was obtained from a middle-aged female patient with carotid duplex sonography, was imposed at the inlets, with all the vascular outlets defined as zero pressure boundary conditions. Time-step size was set at 0.02 seconds; the number of time-steps was set at 40.…”

Impacts of Internal Carotid Artery Revascularization on Flow in Anterior Communicating Artery Aneurysm: A Preliminary Multiscale Numerical Investigation

“…Our previous studies have shown that in the situation of PCoA absence, the collateral flow in ACoAA changes non-linearly with the unilateral ICA stenosis degree due to the collateral mechanism [24,25]. Therefore, instead of considering the region of UIAs alone in the computational domain [44][45][46], modeling the whole anterior circulation would be more appropriate to provide better insight into the hemodynamics change in ACoAA during ICA revascularization.…”

Computational Fluid Dynamics as an Indicator of Offending Vessel in Trigeminal Neuralgia and Hemifacial Spasms

“…CFD has had multiple applications in imaging of the cerebral aneurysms in the past. Some of CFD in cerebral aneurysm include diagnosing thin walled regions in unruptured aneurysms 9 , rupture prediction of intracranial aneurysm 10,11 .…”