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A 3D numerical study of the collateral capacity of the Circle of Willis with anatomical variation in the posterior circulation.

Ren Y, Chen Q, Li ZY - Biomed Eng Online (2015)

Bottom Line: As for the middle cerebral artery (MCA) and the anterior cerebral artery (ACA), the transitional-type model possesses the best collateral capacity.The results demonstrate that different models have different collateral capacities in coping stenosis of unilateral ICA and these differences can be reflected by different outlets.The study could be used as a reference for neurosurgeon in choosing the best treatment strategy.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: The Circle of Willis (CoW) is the most important collateral pathway of the cerebral artery. The present study aims to investigate the collateral capacity of CoW with anatomical variation when unilateral internalcarotid artery (ICA) is occluded.

Methods: Basing on MRI data, we have reconstructed eight 3D models with variations in the posterior circulation of the CoW and set four different degrees of stenosis in the right ICA, namely 24%, 43%, 64% and 79%, respectively. Finally, a total of 40 models are performed with computational fluid dynamics simulations. All of the simulations share the same boundary condition with static pressure and the volume flow rate (VFR) are obtained to evaluate their collateral capacity.

Results: As for the middle cerebral artery (MCA) and the anterior cerebral artery (ACA), the transitional-type model possesses the best collateral capacity. But for the posterior cerebral artery (PCA), unilateral stenosis of ICA has the weakest influence on the unilateral posterior communicating artery (PCoA) absent model. We also find that the full fetal-type posterior circle of Willis is an utmost dangerous variation which must be paid more attention.

Conclusion: The results demonstrate that different models have different collateral capacities in coping stenosis of unilateral ICA and these differences can be reflected by different outlets. The study could be used as a reference for neurosurgeon in choosing the best treatment strategy.

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Related in: MedlinePlus

3D models of the CoW. (a) Patient-specific model. (b) Ideal model. The abbreviation of each artery branch is marked nearby. The last letter "L" and "R" in the abbreviations represent the left and right side of the arteries, respectively. The black dashed box shows the center of the CoW.
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Figure 1: 3D models of the CoW. (a) Patient-specific model. (b) Ideal model. The abbreviation of each artery branch is marked nearby. The last letter "L" and "R" in the abbreviations represent the left and right side of the arteries, respectively. The black dashed box shows the center of the CoW.

Mentions: Blood of the CoW is supplied by two internal carotid arteries (ICAs) and two vertebral arteries (VAs), and they are classified as the afferent arteries. Each ICA bifurcates to form one middle cerebral artery (MCA) and one anterior cerebral artery (ACA). The two VAs anastomose to form the basilar artery (BA) and then bifurcate to form bilateral posterior cerebral arteries (PCAs). Wherein, bilateral ICAs and PCAs are connected with left and right posterior communicating artery (PCoAs), while bilateral ACAs are connected with anterior communicating artery (ACoA). The ACAs, MCAs and PCAs are classified as the efferent arteries and transport blood away from the CoW to supply the whole cerebral tissue. Figure 1 shows the 3D geometric models of the CoW with the left denoting a patient-specific model of a normal subject and the right representing an ideal model. The patient-specific model was reconstructed with SIMPLEWARE software combined with MRA data. To obtain the spatial feature of the CoW, we extracted the central line from the patient-specific model. With the help of CAD software (ANSYS, Geometry), the ideal CoW model was reconstructed with each vessel branch assigned a constant diameter which was statistized in Ref. [23] basing on a huge amount of MR data.


A 3D numerical study of the collateral capacity of the Circle of Willis with anatomical variation in the posterior circulation.

Ren Y, Chen Q, Li ZY - Biomed Eng Online (2015)

3D models of the CoW. (a) Patient-specific model. (b) Ideal model. The abbreviation of each artery branch is marked nearby. The last letter "L" and "R" in the abbreviations represent the left and right side of the arteries, respectively. The black dashed box shows the center of the CoW.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4306100&req=5

Figure 1: 3D models of the CoW. (a) Patient-specific model. (b) Ideal model. The abbreviation of each artery branch is marked nearby. The last letter "L" and "R" in the abbreviations represent the left and right side of the arteries, respectively. The black dashed box shows the center of the CoW.
Mentions: Blood of the CoW is supplied by two internal carotid arteries (ICAs) and two vertebral arteries (VAs), and they are classified as the afferent arteries. Each ICA bifurcates to form one middle cerebral artery (MCA) and one anterior cerebral artery (ACA). The two VAs anastomose to form the basilar artery (BA) and then bifurcate to form bilateral posterior cerebral arteries (PCAs). Wherein, bilateral ICAs and PCAs are connected with left and right posterior communicating artery (PCoAs), while bilateral ACAs are connected with anterior communicating artery (ACoA). The ACAs, MCAs and PCAs are classified as the efferent arteries and transport blood away from the CoW to supply the whole cerebral tissue. Figure 1 shows the 3D geometric models of the CoW with the left denoting a patient-specific model of a normal subject and the right representing an ideal model. The patient-specific model was reconstructed with SIMPLEWARE software combined with MRA data. To obtain the spatial feature of the CoW, we extracted the central line from the patient-specific model. With the help of CAD software (ANSYS, Geometry), the ideal CoW model was reconstructed with each vessel branch assigned a constant diameter which was statistized in Ref. [23] basing on a huge amount of MR data.

Bottom Line: As for the middle cerebral artery (MCA) and the anterior cerebral artery (ACA), the transitional-type model possesses the best collateral capacity.The results demonstrate that different models have different collateral capacities in coping stenosis of unilateral ICA and these differences can be reflected by different outlets.The study could be used as a reference for neurosurgeon in choosing the best treatment strategy.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Background: The Circle of Willis (CoW) is the most important collateral pathway of the cerebral artery. The present study aims to investigate the collateral capacity of CoW with anatomical variation when unilateral internalcarotid artery (ICA) is occluded.

Methods: Basing on MRI data, we have reconstructed eight 3D models with variations in the posterior circulation of the CoW and set four different degrees of stenosis in the right ICA, namely 24%, 43%, 64% and 79%, respectively. Finally, a total of 40 models are performed with computational fluid dynamics simulations. All of the simulations share the same boundary condition with static pressure and the volume flow rate (VFR) are obtained to evaluate their collateral capacity.

Results: As for the middle cerebral artery (MCA) and the anterior cerebral artery (ACA), the transitional-type model possesses the best collateral capacity. But for the posterior cerebral artery (PCA), unilateral stenosis of ICA has the weakest influence on the unilateral posterior communicating artery (PCoA) absent model. We also find that the full fetal-type posterior circle of Willis is an utmost dangerous variation which must be paid more attention.

Conclusion: The results demonstrate that different models have different collateral capacities in coping stenosis of unilateral ICA and these differences can be reflected by different outlets. The study could be used as a reference for neurosurgeon in choosing the best treatment strategy.

Show MeSH
Related in: MedlinePlus