Does the gravity orientation of saccular aneurysms influence hemodynamics? An experimental study with and without flow diverter stent.
Most intracranial aneurysms morphologic studies focused on characterization of size, location, aspect ratio, relationship to the surrounding vasculature and hemodynamics. However, the spatial orientation with respect to the gravity direction has not been taken into account although it could trigger various hemodynamic conditions. The present work addresses this possibility. It was divided in two parts: 1) the orientations of 18, 3D time-of-flight MRI (3D TOF MRI), scans of saccular aneurysms were analyzed. This investigation suggested that there was no privileged orientation for cerebral aneurysms. The aneurysms were oriented in the brain as follows: 9 - down, 9 - up; 11 - right, 7 - left; 6 - front, 12 - back. 2) Based on these results, subsidiary in vitro experiments were performed, analyzing the behavior of red blood cells (RBCs) within a silicone model of aneurysm before and after flow diverter stent (FDS) deployment in the parent vessel. These experiments used a test bench that reproduces physiological pulsatile flow conditions for two orientations: an aneurysm sack pointing either up (opposite to gravitational force) and down (along the gravitational force). The results showed that the orientation of an aneurysm significantly affects the intra-aneurysmal RBCs behavior after stenting, and therefore that gravity can affect the intra-aneurysm behavior of RBCs. This suggests that the patient׳s aneurysm orientation could impact the outcome of the FDS treatment. The implementation of this effect in patient-specific numerical and preoperative decision support techniques could contribute to better understand the intrasaccular biological and hemodynamic events induced by FDS.
Laboratory of Experimental Medicine (ULB 222 unit), Université Libre de Bruxelles, Chu de Charleroi, Belgium. Electronic address: kamil.chodzynski@chu-charleroi.be.
Kamil J
KJ
Chodzyński
Department of Neuroradiology, Hôpital Gui de Chauliac, CHRU Montpellier, France.
Omer F
OF
Eker
Laboratory of Experimental Medicine (ULB 222 unit), Université Libre de Bruxelles, Chu de Charleroi, Belgium.
Axel E
AE
Vanrossomme
Laboratory of Experimental Medicine (ULB 222 unit), Université Libre de Bruxelles, Chu de Charleroi, Belgium.
Daniel Ribeiro
DR
de Sousa
Department of Fluids-Machines, Faculty of Engineering, University of Mons, Belgium.
Grégory
G
Coussement
Laboratory of Experimental Medicine (ULB 222 unit), Université Libre de Bruxelles, Chu de Charleroi, Belgium; Institute for Molecular Biology and Medicine (IBMM), Université Libre de Bruxelles, Belgium.
Luc
L
Vanhamme
Microgravity Research Center (MRC), Université Libre de Bruxelles, Belgium.
Frank
F
Dubois
Department of Neuroradiology, Hôpital Gui de Chauliac, CHRU Montpellier, France.
Alain
A
Bonafé
Scientific and Parallel Computing Group, CUI, University of Geneva, Switzerland.
Bastien
B
Chopard
Univ Lyon, CNRS UMR 5220, INSERM U1206, Université Lyon1, Université Jean Monnet Saint-Etienne, INSA Lyon, CREATIS, F-69621, LYON, France.
Guy
G
Courbebaisse
Laboratory of Experimental Medicine (ULB 222 unit), Université Libre de Bruxelles, Chu de Charleroi, Belgium.
Karim
K
Zouaoui Boudjeltia
D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology; D002560:Cerebrovascular Circulation; D004912:Erythrocytes / Q000502:physiology; D005260:Female; D006112:Gravitation; D006439:Hemodynamics; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D015607:Stents
Flow diverter stent; Gravity; In vitro test bench; Intracranial aneurysms; Red Blood Cells