Impact of bifurcation angle and inflow coefficient on the rupture risk of bifurcation type basilar artery tip aneurysms

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OBJECTIVE

Risk factors for aneurysm rupture have been extensively studied, with several factors showing significant correlations with rupture status. Several studies have shown that aneurysm shape and hemodynamics change after rupture. In the present study the authors investigated a static factor, the bifurcation angle, which does not change after rupture, to understand its effect on aneurysm rupture risk and hemodynamics.

METHODS

A hospital database was retrospectively reviewed to identify patients with cerebral aneurysms treated surgically or endovascularly in the period between 2008 and 2015. After acquiring 3D rotational angiographic data, 3D stereolithography models were created and computational fluid dynamic analysis was performed using commercially available software. Patient data (age and sex), morphometric factors (aneurysm volume and maximum height, aspect ratio, bifurcation angle, bottleneck ratio, and neck/parent artery ratio), and hemodynamic factors (inflow coefficient and wall shear stress) were statistically compared between ruptured and unruptured groups.

RESULTS

Seventy-one basilar tip aneurysms were included in this study, 22 ruptured and 49 unruptured. Univariate analysis showed aspect ratio, bifurcation angle, bottleneck ratio, and inflow coefficient were significantly correlated with a ruptured status. Logistic regression analysis showed that aspect ratio and bifurcation angle were significant predictors of a ruptured status. Bifurcation angle was inversely correlated with inflow coefficient (p < 0.0005), which in turn correlated directly with mean (p = 0.028) and maximum (p = 0.014) wall shear stress (WSS) using Pearson's correlation coefficient, whereas aspect ratio was inversely correlated with mean (0.012) and minimum (p = 0.018) WSS.

CONCLUSIONS

Bifurcation angle and aspect ratio are independent predictors for aneurysm rupture. Bifurcation angle, which does not change after rupture, is correlated with hemodynamic factors including inflow coefficient and WSS, as well as rupture status. Aneurysms with the hands-up bifurcation configuration are more prone to rupture than aneurysms with other bifurcation configurations.

ABBREVIATIONS AUC = area under the curve; HD = hands-down; HN = hands-neutral; HU = hands-up; ROC = receiver operating characteristic; WSS = wall shear stress.
Article Information

Contributor Notes

Correspondence Kuniyasu Niizuma, Department of Neurosurgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. email: niizuma@nsg.med.tohoku.ac.jp.INCLUDE WHEN CITING Published online March 3, 2017; DOI: 10.3171/2016.10.JNS161695.Disclosures The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
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References
  • 1

    Amenta PSYadla SCampbell PGMaltenfort MGDey SGhosh S: Analysis of nonmodifiable risk factors for intracranial aneurysm rupture in a large, retrospective cohort. Neurosurgery 70:6937012012

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 2

    Baharoglu MISchirmer CMHoit DAGao BLLMalek AM: Aneurysm inflow-angle as a discriminant for rupture in sidewall cerebral aneurysms: morphometric and computational fluid dynamic analysis. Stroke 41:142314302010

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3

    Brinjikji WZhu YQLanzino GCloft HJMurad MHWang Z: Risk factors for growth of intracranial aneurysms: a systematic review and meta-analysis.. AJNR Am J Neuroradiol [epub ahead of print]2015

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4

    Brisman JLSong JKNewell DW: Cerebral aneurysms. N Engl J Med 355:9289392006

  • 5

    Chien ASayre J: Morphologic and hemodynamic risk factors in ruptured aneurysms imaged before and after rupture. AJNR Am J Neuroradiol 35:213021352014

  • 6

    Cornelissen BMSchneiders JJPotters WVvan den Berg RVelthuis BKRinkel GJ: Hemodynamic differences in intracranial aneurysms before and after rupture. AJNR Am J Neuroradiol 36:192719332015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 7

    Greving JPWermer MJBrown RD JrMorita AJuvela SYonekura M: Development of the PHASES score for prediction of risk of rupture of intracranial aneurysms: a pooled analysis of six prospective cohort studies. Lancet Neurol 13:59662014

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 8

    Hassan TTimofeev EVSaito TShimizu HEzura MMatsumoto Y: A proposed parent vessel geometry-based categorization of saccular intracranial aneurysms: computational flow dynamics analysis of the risk factors for lesion rupture. J Neurosurg 103:6626802005

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 9

    Ho ALMouminah ADu R: Posterior cerebral artery angle and the rupture of basilar tip aneurysms. PLoS One 9:e1109462014

  • 10

    Hoh BLSistrom CLFirment CSFautheree GLVelat GJWhiting JH: Bottleneck factor and height-width ratio: association with ruptured aneurysms in patients with multiple cerebral aneurysms. Neurosurgery 61:7167232007

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 11

    Juvela SPorras MPoussa K: Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture. J Neurosurg 108:105210602008

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 12

    Lin NHo AGross BAPieper SFrerichs KUDay AL: Differences in simple morphological variables in ruptured and unruptured middle cerebral artery aneurysms. J Neurosurg 117:9139192012

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 13

    Meng HTutino VMXiang JSiddiqui A: High WSS or low WSS? Complex interactions of hemodynamics with intracranial aneurysm initiation, growth, and rupture: toward a unifying hypothesis. AJNR Am J Neuroradiol 35:125412622014

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 14

    Nikolic ITasic GBogosavljevic VNestorovic BJovanovic VKojic Z: Predictable morphometric parameters for rupture of intracranial aneurysms—a series of 142 operated aneurysms. Turk Neurosurg 22:4204262012

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 15

    Prestigiacomo CJHe WCatrambone JChung SKasper LPasupuleti L: Predicting aneurysm rupture probabilities through the application of a computed tomography angiography-derived binary logistic regression model. J Neurosurg 110:162009

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 16

    Schneiders JJMarquering HAvan den Berg RVanBavel EVelthuis BRinkel GJ: Rupture-associated changes of cerebral aneurysm geometry: high-resolution 3D imaging before and after rupture. AJNR Am J Neuroradiol 35:135813622014

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 17

    Shojima MOshima MTakagi KTorii RHayakawa MKatada K: Magnitude and role of wall shear stress on cerebral aneurysm: computational fluid dynamic study of 20 middle cerebral artery aneurysms. Stroke 35:250025052004

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 18

    Vlak MHAlgra ABrandenburg RRinkel GJ: Prevalence of unruptured intracranial aneurysms, with emphasis on sex, age, comorbidity, country, and time period: a systematic review and meta-analysis. Lancet Neurol 10:6266362011

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19

    Wiebers DOTorner JCMeissner I: Impact of unruptured intracranial aneurysms on public health in the United States. Stroke 23:141614191992

  • 20

    Xiang JNatarajan SKTremmel MMa DMocco JHopkins LN: Hemodynamic-morphologic discriminants for intracranial aneurysm rupture. Stroke 42:1441522011

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 21

    Yasuda RStrother CMTaki WShinki KRoyalty KPulfer K: Aneurysm volume-to-ostium area ratio: a parameter useful for discriminating the rupture status of intracranial aneurysms. Neurosurgery 68:3103182011

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 22

    You SHHKong DSSKim JSSJeon PKim KHRoh HK: Characteristic features of unruptured intracranial aneurysms: predictive risk factors for aneurysm rupture. J Neurol Neurosurg Psychiatry 81:4794842010

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 23

    Zarins CKZatina MAGiddens DPKu DNGlagov S: Shear stress regulation of artery lumen diameter in experimental atherogenesis. J Vasc Surg 5:4134201987

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24

    Zhang YMu SChen JWang SLi HYu H: Hemodynamic analysis of intracranial aneurysms with daughter blebs. Eur Neurol 66:3593672011

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