PT  - JOURNAL ARTICLE
AU  - Narata, A.P.
AU  - de Moura, F.S.
AU  - Larrabide, I.
AU  - Perrault, C.M.
AU  - Patat, F.
AU  - Bibi, R.
AU  - Velasco, S.
AU  - Januel, A.-C.
AU  - Cognard, C.
AU  - Chapot, R.
AU  - Bouakaz, A.
AU  - Sennoga, C.A.
AU  - Marzo, A.
TI  - The Role of Hemodynamics in Intracranial Bifurcation Arteries after Aneurysm Treatment with Flow-Diverter Stents
AID  - 10.3174/ajnr.A5471
DP  - 2018 Feb 01
TA  - American Journal of Neuroradiology
PG  - 323--330
VI  - 39
IP  - 2
4099  - http://www.ajnr.org/content/39/2/323.short
4100  - http://www.ajnr.org/content/39/2/323.full
SO  - Am. J. Neuroradiol.2018 Feb 01; 39
AB  - BACKGROUND AND PURPOSE: Treatment of intracranial bifurcation aneurysms with flow-diverter stents can lead to caliber changes of the distal vessels in a subacute phase. This study aims to evaluate whether local anatomy and flow disruption induced by flow-diverter stents are associated with vessel caliber changes in intracranial bifurcations.MATERIALS AND METHODS: Radiologic images and demographic data were acquired for 25 patients with bifurcation aneurysms treated with flow-diverter stents. Whisker plots and Mann-Whitney rank sum tests were used to evaluate if anatomic data and caliber changes could be linked. Symmetry/asymmetry were defined as diameter ratio 1 = symmetric and diameter ratio <1 = asymmetric. Computational fluid dynamics was performed on idealized and patient-specific anatomies to evaluate flow changes induced by flow-diverter stents in the jailed vessel.RESULTS: Statistical analysis identified a marked correspondence between asymmetric bifurcation and caliber change. Symmetry ratios were lower for cases showing narrowing or subacute occlusion (medium daughter vessel diameter ratio = 0.59) compared with cases with posttreatment caliber conservation (medium daughter vessel diameter ratio = 0.95). Computational fluid dynamics analysis in idealized and patient-specific anatomies showed that wall shear stress in the jailed vessel was more affected when flow-diverter stents were deployed in asymmetric bifurcations (diameter ratio <0.65) and less affected when deployed in symmetric anatomies (diameter ratio ∼1.00).CONCLUSIONS: Anatomic data analysis showed statistically significant correspondence between caliber changes and bifurcation asymmetry characterized by diameter ratio <0.7 (P < .001). Similarly, computational fluid dynamics results showed the highest impact on hemodynamics when flow-diverter stents are deployed in asymmetric bifurcations (diameter ratio <0.65) with noticeable changes on wall sheer stress fields. Further research and clinical validation are necessary to identify all elements involved in vessel caliber changes after flow-diverter stent procedures.DRdaughter vessel diameter ratioFDSflow-diverter stentWSSwall shear stress