AneurysmIntra-aneurysmal hemodynamics in a large middle cerebral artery aneurysm with wall atherosclerosis
Section snippets
Objectives
The human artery is capable of sensing environmental changes such as the magnitude of fluid-induced wall shear stress and alters its histologic structure in responding to those changes [5], [6]. This histologic alteration is called arterial remodeling [6], [12], [21], [24]. The fluid-induced wall shear stress is a very small frictional force on the inner surface of the vessels induced by running blood, and the capacity of the endothelial cell to sense the magnitude of wall shears tress is one
In vitro aneurysm models
One unruptured large MCA aneurysm on the right was selected from the UCLA aneurysm CTA library. The aneurysm measured 16.6 mm in its largest diameter with a neck size of 5.8 mm. Moderate atherosclerotic changes were noted on the aneurysm wall during the surgical exposure, and 4 clips were used to obliterate the aneurysm (Fig. 1). An in vitro aneurysm model made of silicon rubber was constructed based on the patient's CTA (Fig. 2). The construction method of in vitro aneurysm model has been
Results
The hemodynamic spectrum of this aneurysm is presented in Fig. 3. An inward flow is noted in the anterior-superior aspect of the aneurysm (Fig. 3A, B), and the inward flow moves toward posterior-inferior direction along the lateral wall of the aneurysm (Fig. 3C, D). A slower outward flow moves superiorly along the medial wall of the aneurysm (Fig. 3B, C, and E). The plaque was located posteriorly on the lateral side and was exposed to a unidirectional flow (Fig. 3C, D).
The magnitude of the wall
Discussion
The arterial remodeling is involved in the pathogenesis of various vascular diseases such as atherosclerotic plaque formation [5], [6], [22]. The endothelial cell is sensitive to sustained changes of wall shear stress and plays a key role in the normal and pathologic arterial remodeling processes. In responding to the changes in the magnitude of wall shear stress, the endothelial cell modulates the functions of arterial wall, including regulation of the permeability of plasma lipoproteins,
Conclusions
The authors present hemodynamic data collected from an in vitro model of a large MCA aneurysm with a wall atherosclerotic plaque. The atherosclerotic portion of the aneurysm wall showed lower shear stress when compared with nonatherosclerotic portions of the wall of the aneurysm. These findings are in keeping with hemodynamic findings in other vascular diseases such as carotid atherosclerotic plaques.
References (24)
- et al.
Transcranial Doppler ultrasound for the assessment of intracranial arterial flow velocity—part 1: examination technique and normal values
Surg Neurol
(1987) - et al.
Shear-stress effect on mitochondrial membrane potential and albumin uptake in cultured endothelial cells
Biochem Biophys Res Commun
(2000) - et al.
Challenges and opportunities in abdominal aortic aneurysm research
J Vasc Surg
(2007) Aspects of fluid dynamics applied to the larger arteries
J Theol Biol
(1999)- et al.
Macrophage-derived matrix metalloproteinase-2 and -9 promote the progression of cerebral aneurysms in rats
Stroke
(2007) - et al.
Vascular extracellular matrix remodeling in cerebral aneurysms
J Neurosurg
(1988) - et al.
- et al.
Characterization of cerebral aneurysms for assessing risk of rupture by using patient-specific computational hemodynamics models
Am J Neuroradiol
(2005) - et al.
Matrix metalloproteinases in vascular remodeling and atherogenesis: the good, the bad, and the ugly
Circ Res
(2002) - et al.
The emerging concept of vascular remodeling
N Engl J Med
(1994)
A proposed parent vessel geometry-based categorization of saccular intracranial aneurysms: computational flow dynamics analysis of the risk factors for lesion rupture
J Neurosurg
Swine model of carotid artery atherosclerosis: experimental induction by surgical partial ligation and dietary hypercholesterolemia
Am J Neuroradiol
Cited by (15)
Predictors of Atherosclerotic Change in Unruptured Intracranial Aneurysms and Parent Arteries During Clipping
2019, World NeurosurgeryCitation Excerpt :Previous studies have reported that thin or translucent portions of the aneurysmal wall were correlated with rupture points.6,24 Another study revealed that shear stress acting on an arterial wall tended to be lower in areas with atherosclerotic changes than in areas without such changes.25 Atherosclerosis might induce stenosis or kinking of a parent artery during ligation, which could indicate that atherosclerosis has progressed to a clinically relevant point.
Computational Fluid Dynamics Analysis Features in Aneurysm Development in Rats
2023, Neurologia Medico-ChirurgicaFluid–structure interaction (FSI) simulation for studying the impact of atherosclerosis on hemodynamics, arterial tissue remodeling, and initiation risk of intracranial aneurysms
2022, Biomechanics and Modeling in Mechanobiology